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Hopf fibration

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2074: 6633: 1683: 31: 67: 2069:{\displaystyle 2z_{0}z_{1}^{\ast }\cdot 2z_{0}^{\ast }z_{1}+\left(\left|z_{0}\right|^{2}-\left|z_{1}\right|^{2}\right)^{2}=4\left|z_{0}\right|^{2}\left|z_{1}\right|^{2}+\left|z_{0}\right|^{4}-2\left|z_{0}\right|^{2}\left|z_{1}\right|^{2}+\left|z_{1}\right|^{4}=\left(\left|z_{0}\right|^{2}+\left|z_{1}\right|^{2}\right)^{2}=1} 4780: 5507: 5771:
of fluid dynamics in which the fluid flows along the circles of the projection of the Hopf fibration in 3 dimensional space. The size of the velocities, the density and the pressure can be chosen at each point to satisfy the equations. All these quantities fall to zero going away from the centre. If
5739:. The Hopf mapping maps the rotation to the point on the 2-sphere given by θ and φ, and the associated circle is parametrized by ψ. Note that when θ = π the Euler angles φ and ψ are not well defined individually, so we do not have a one-to-one mapping (or a one-to-two mapping) between the 4400: 6706:: the former maps to a straight line, the latter to a unit circle perpendicular to, and centered on, this line, which may be viewed as a degenerate torus whose minor radius has shrunken to zero. Every other fiber image encircles the line as well, and so, by symmetry, each circle is linked through 6007: 4471: 1610: 1191: 5302: 5220: 4244: 3702: 2836: 2750: 2664: 2578: 1322: 3894: 6140: 6260: 4924: 2482: 235: 2396: 5638: 5053: 5778: 7243: 650: 6824: 593: 536: 479: 826: 3126: 3068: 3945: 5690:
in three dimensions. The set of all possible quaternions produces the set of all possible rotations, which moves the tip of one unit vector of such a coordinate frame (say, the
4775:{\displaystyle {\begin{bmatrix}1-2(y^{2}+z^{2})&2(xy-wz)&2(xz+wy)\\2(xy+wz)&1-2(x^{2}+z^{2})&2(yz-wx)\\2(xz-wy)&2(yz+wx)&1-2(x^{2}+y^{2})\end{bmatrix}}.} 861: 422:
versions of these fibrations. In particular, the Hopf fibration belongs to a family of four fiber bundles in which the total space, base space, and fiber space are all spheres:
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as total space, base space, and fiber can occur only in these dimensions. Fiber bundles with similar properties, but different from the Hopf fibrations, were used by
3524:; its elements are angles of rotation leaving the given point unmoved, all sharing the axis connecting that point to the sphere's center. It follows easily that the 755: 712: 5502:{\displaystyle {\frac {1}{\sqrt {2(1+c)}}}{\Big (}(1+c)\cos(\theta ),a\sin(\theta )-b\cos(\theta ),a\cos(\theta )+b\sin(\theta ),(1+c)\sin(\theta ){\Big )}.\,\!} 5113: 4395:{\displaystyle {\begin{bmatrix}x_{1}+\mathbf {i} x_{2}&x_{3}+\mathbf {i} x_{4}\\-x_{3}+\mathbf {i} x_{4}&x_{1}-\mathbf {i} x_{2}\end{bmatrix}}.\,\!} 3615: 2756: 2670: 2584: 2498: 1202: 3820: 6013: 6146: 7465: 7132: 6979: 4801: 2402: 171: 2319: 7262: 5561: 5002: 5767:
If the Hopf fibration is treated as a vector field in 3 dimensional space then there is a solution to the (compressible, non-viscous)
6002:{\displaystyle \mathbf {v} (x,y,z)=A\left(a^{2}+x^{2}+y^{2}+z^{2}\right)^{-2}\left(2(-ay+xz),2(ax+yz),a^{2}-x^{2}-y^{2}+z^{2}\right)} 7277: 6305:, admits several generalizations, which are also often known as Hopf fibrations. First, one can replace the projective line by an 6935: 6910: 363:
in space (one of which is a line, thought of as a "circle through infinity"). Each torus is the stereographic projection of the
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Banchoff, Thomas (1988). "Geometry of the Hopf Mapping and Pinkall's Tori of Given Conformal Type". In Tangora, Martin (ed.).
726:, and the distance of the points on the sphere from this origin can be assumed to be a unit length. With this convention, the 377:
is compressed to the boundary of a ball, some geometric structure is lost although the topological structure is retained (see
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YouTube animation showing dynamic mapping of points on the 2-sphere to circles in the 3-sphere, by Professor Niles Johnson.
7451: 6995: 599: 371:-sphere. (Topologically, a torus is the product of two circles.) These tori are illustrated in the images at right. When 7561: 7504:
Zamboj, Michal (8 Jan 2021). "Synthetic construction of the Hopf fibration in a double orthogonal projection of 4-space".
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which fill space. Here there is one exception: the Hopf circle containing the projection point maps to a straight line in
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Watterson, Michael; Kumar, Vijay (2020). Amato, Nancy M.; Hager, Greg; Thomas, Shawna; Torres-Torriti, Miguel (eds.).
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acts as a rotation of quaternion space, the fiber is not merely a topological circle, it is a geometric circle.
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Here we find an explicit real formula for the bundle projection by noting that the fixed unit vector along the
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Sometimes the term "Hopf fibration" is restricted to the fibrations between spheres obtained above, which are
7591: 4174:, will have the same effect. We put all these into one fibre, and the fibres can be mapped one-to-one to the 7313: 3529: 3507: 3366: 3228: 3137: 6667:). Stereographic projection preserves circles and maps the Hopf fibers to geometrically perfect circles in 7652: 7220: 3909: 103: 7268: 6849: 6377: 3552: 3488: 831: 79: 3475:
Another geometric interpretation of the Hopf fibration can be obtained by considering rotations of the
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Mosseri, R.; Dandoloff, R. (2001), "Geometry of entangled states, Bloch spheres and Hopf fibrations",
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on these tori, with the exception of the circle through the projection point and the one through its
6350: 6282: 3484: 3174: 1672:, as may be shown by adding the squares of the absolute values of the complex and real components of 723: 7551: 2974: 6767:. Similarly, the topology of a pair of entangled two-level systems is given by the Hopf fibration 1605:{\displaystyle p(z_{0},z_{1})=(2z_{0}z_{1}^{\ast },\left|z_{0}\right|^{2}-\left|z_{1}\right|^{2}).} 719: 123: 1186:{\displaystyle (x_{1},x_{2},x_{3},x_{4})\leftrightarrow (z_{0},z_{1})=(x_{1}+ix_{2},x_{3}+ix_{4})} 7513: 7435: 7409: 7387: 7361: 7297: 7187: 7138: 7107: 6699: 6637: 1615:
The first component is a complex number, whereas the second component is real. Any point on the
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a is the distance to the inner ring, the velocities, pressure and density fields are given by:
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The Hopf fibration has many implications, some purely attractive, others deeper. For example,
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above defines an explicit diffeomorphism between the complex projective line and the ordinary
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Interactive visualization of the mapping of points on the 2-sphere to circles in the 3-sphere
7344: 7523: 7493: 7427: 7371: 7322: 7281: 7229: 7171: 7120: 7077: 7061: 7028: 6897: 6760: 6314: 6310: 3544: 3361:. This means that it has a "local product structure", in the sense that every point of the 332: 2079:
Furthermore, if two points on the 3-sphere map to the same point on the 2-sphere, i.e., if
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This has many implications: for example the existence of this bundle shows that the higher
290:-sphere). The Hopf fibration, like any fiber bundle, has the important property that it is 7447: 6703: 3548: 3411: 3147: 715: 291: 7612: 7159:"Accurate High-Maneuvering Trajectory Tracking for Quadrotors: A Drag Utilization Method" 7489: 7423: 7024: 5215:{\displaystyle q_{(a,b,c)}={\frac {1}{\sqrt {2(1+c)}}}(1+c-\mathbf {i} b+\mathbf {j} a)} 4136:
Another way to look at this fibration is that every versor ω moves the plane spanned by
158:-sphere is composed of fibers, where each fiber is a circle — one for each point of the 7212: 7082: 7049: 6737: 6733: 6729: 6609: 3256: 2303: 1019: 668: 656: 7497: 7431: 5678:
Thus, a simple way of visualizing the Hopf fibration is as follows. Any point on the
7631: 7439: 7301: 7239: 7208: 7191: 7142: 6944: 6917: 6759:, and the Hopf fibration describes the topological structure of a quantum mechanical 6621: 5706:
vector does not specify the rotation fully; a further rotation is possible about the
3499: 3383: 3379: 2272: 364: 295: 351:, in which all of 3-dimensional space, except for the z-axis, is filled with nested 6967: 6833:). Moreover, the Hopf fibration is equivalent to the fiber bundle structure of the 6756: 6690:(topologically, a torus is the product of two circles) and these project to nested 6525: 5725: 5078: 3521: 3352: 382: 336: 143: 119: 6632: 3697:{\displaystyle q=x_{1}+\mathbf {i} x_{2}+\mathbf {j} x_{3}+\mathbf {k} x_{4}.\,\!} 7124: 7588:
Chapters 7 and 8 illustrate the Hopf fibration with animated computer graphics.
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in the usual way and by identifying antipodal points. This gives a fiber bundle
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This approach is related to the direct construction by identifying a quaternion
2831:{\displaystyle x_{4}=\sin \left({\frac {\xi _{2}-\xi _{1}}{2}}\right)\cos \eta } 2745:{\displaystyle x_{3}=\cos \left({\frac {\xi _{2}-\xi _{1}}{2}}\right)\cos \eta } 2659:{\displaystyle x_{2}=\sin \left({\frac {\xi _{1}+\xi _{2}}{2}}\right)\sin \eta } 2573:{\displaystyle x_{1}=\cos \left({\frac {\xi _{1}+\xi _{2}}{2}}\right)\sin \eta } 411: 99: 7606: 7601: 7158: 4015:
determine the same rotation. As noted above, the rotations act transitively on
7311:(1935), "Über die Abbildungen von Sphären auf Sphären niedrigerer Dimension", 7308: 7257: 7233: 6857: 6853: 6440: 5683: 3492: 2916: 415: 115: 7571: 7383: 7336: 7293: 7183: 7175: 7073: 7065: 1317:{\displaystyle (x_{1},x_{2},x_{3})\leftrightarrow (z,x)=(x_{1}+ix_{2},x_{3})} 392:
There are numerous generalizations of the Hopf fibration. The unit sphere in
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Yershova, Anna; Jain, Swati; LaValle, Steven M.; Mitchell, Julie C. (2010).
6719: 4996:. Multiplication of unit quaternions produces composition of rotations, and 3889:{\displaystyle p=\mathbf {i} y_{1}+\mathbf {j} y_{2}+\mathbf {k} y_{3}.\,\!} 247: 30: 7527: 7091: 17: 7622: 6636:
The fibers of the Hopf fibration stereographically project to a family of
6135:{\displaystyle p(x,y,z)=-A^{2}B\left(a^{2}+x^{2}+y^{2}+z^{2}\right)^{-3},} 5643:
which completes the bundle. But note that this one-to-one mapping between
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form the unit circle in the complex plane, it follows that for each point
66: 7414: 7050:"Generating Uniform Incremental Grids on SO (3) Using the Hopf Fibration" 6879:-sphere into disjoint great circles is possible because, unlike with the 6841: 6486: 6333:
A real version of the Hopf fibration is obtained by regarding the circle
6322: 4083:, and then the Hopf fibration can be defined as the map sending a versor 3957: 679: 419: 378: 95: 6255:{\displaystyle \rho (x,y,z)=3B\left(a^{2}+x^{2}+y^{2}+z^{2}\right)^{-1}} 4971:
consists of all those unit quaternions that send the unit vector there.
27:
Fiber bundle of the 3-sphere over the 2-sphere, with 1-spheres as fibers
7616: 7391: 7285: 7263:"Über die Abbildungen der dreidimensionalen Sphäre auf die Kugelfläche" 6278: 5740: 4919:{\displaystyle {\Big (}2(xz+wy),2(yz-wx),1-2(x^{2}+y^{2}){\Big )},\,\!} 107: 71: 7033: 7008: 3136:
A geometric interpretation of the fibration may be obtained using the
2477:{\displaystyle z_{1}=e^{i\,{\frac {\xi _{2}-\xi _{1}}{2}}}\cos \eta .} 230:{\displaystyle S^{1}\hookrightarrow S^{3}{\xrightarrow {\ p\,}}S^{2},} 7518: 6613: 3993: 3712: 2391:{\displaystyle z_{0}=e^{i\,{\frac {\xi _{1}+\xi _{2}}{2}}}\sin \eta } 1335: 386: 360: 111: 7474:
Urbantke, H.K. (2003), "The Hopf fibration-seven times in physics",
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Jia, Jindou; Guo, Kexin; Yu, Xiang; Zhao, Weihua; Guo, Lei (2022).
4117:, get mapped to the same thing (which happens to be one of the two 6764: 6691: 6683: 6631: 3555: 2959:-sphere is as follows, with points on the circles parametrized by 352: 331:
are not trivial in general. It also provides a basic example of a
65: 29: 5633:{\displaystyle {\Big (}0,\cos(\theta ),-\sin(\theta ),0{\Big )},} 5048:{\displaystyle q_{\theta }=\cos \theta +\mathbf {k} \sin \theta } 4974:
We can also write an explicit formula for the fiber over a point
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To make this more explicit, there are two approaches: the group
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By Gian Marco Todesco shows the Hopf fibration of the 120-cell.
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algorithm in motion planning. It also found application in the
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causes you to make one full circle of both limbs of the torus.
2190:-sphere. These conclusions follow, because the complex factor 7595: 3417:
For the Hopf fibration, it is enough to remove a single point
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there is a circle of unit norm, and so the restriction of the
3989:, and it is not hard to check that it preserves orientation. 722:. For concreteness, the central point can be taken to be the 6698:
which also fill space. The individual fibers map to linking
6313:. Second, one can replace the complex numbers by any (real) 5686:, which in turn is equivalent to a particular rotation of a 4073:. This is a circle subgroup. For concreteness, one can take 5659:
is not continuous on this circle, reflecting the fact that
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Geometric interpretation using the complex projective line
7108:"Control of Quadrotors Using the Hopf Fibration on SO(3)" 6996:
sci.math.research 1993 thread "Spheres fibred by spheres"
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https://ncatlab.org/nlab/show/quaternionic+Hopf+fibration
6663:, which in turn illuminates the topology of the bundle ( 4409:, and the imaginary quaternions with the skew-hermitian 345:
of the Hopf fibration induces a remarkable structure on
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YouTube animation of the construction of the 120-cell
6776: 6149: 6016: 5781: 5564: 5305: 5116: 5087:, our prototypical fiber. So long as the base point, 5005: 4804: 4474: 4247: 3912: 3823: 3618: 3077: 3019: 2977: 2759: 2673: 2587: 2501: 2405: 2322: 1686: 1473: 1205: 1031: 834: 763: 736: 688: 645:{\displaystyle S^{7}\hookrightarrow S^{15}\to S^{8}.} 602: 545: 488: 431: 174: 7539:. New York and Basel: Marcel Dekker. pp. 57–62. 7119:. Cham: Springer International Publishing: 199–215. 6819:{\displaystyle S^{3}\hookrightarrow S^{7}\to S^{4}.} 2176:. The converse is also true; any two points on the 659:
such fibrations can occur only in these dimensions.
588:{\displaystyle S^{3}\hookrightarrow S^{7}\to S^{4},} 531:{\displaystyle S^{1}\hookrightarrow S^{3}\to S^{2},} 474:{\displaystyle S^{0}\hookrightarrow S^{1}\to S^{1},} 6844:, where it was used to generate uniform samples on 62:
and their corresponding fibers with the same color.
7401:Journal of Physics A: Mathematical and Theoretical 7345:"An Elementary Introduction to the Hopf Fibration" 7261: 7245:The collected mathematical papers of Arthur Cayley 7157: 7106: 6818: 6254: 6134: 6001: 5632: 5501: 5214: 5047: 4918: 4774: 4394: 3939: 3888: 3696: 3120: 3062: 3004: 2830: 2744: 2658: 2572: 2476: 2390: 2068: 1604: 1316: 1185: 855: 820: 749: 706: 644: 587: 530: 473: 324:although locally it is indistinguishable from it. 229: 5622: 5567: 5498: 5489: 5335: 4959:-sphere where it sends the unit vector along the 4915: 4906: 4807: 4391: 3936: 3885: 3693: 118:in 1931, it is an influential early example of a 7592:An Elementary Introduction to the Hopf Fibration 6830: 6293:The Hopf construction, viewed as a fiber bundle 7506:Journal of Computational Design and Engineering 2180:-sphere that differ by a common complex factor 7054:The International Journal of Robotics Research 3255:-sphere: indeed it can be identified with the 2955:A mapping of the above parametrization to the 2313:-sphere employing the Hopf map is as follows. 7115:. Springer Proceedings in Advanced Robotics. 6446:-space) and factor out by unit quaternion (= 3300:-dimensional space. Alternatively, the point 3231:to the points of unit norm is a fibration of 821:{\displaystyle (x_{1},x_{2},\ldots ,x_{n+1})} 34:The Hopf fibration can be visualized using a 8: 7213:"On certain results relating to quaternions" 6937:Topological solitons in magnetohydrodynamics 2915:which specify circles, specifies a separate 682:, can be defined as the set of points in an 385:to circles, although they are not geometric 6972:Manifolds all of whose Geodesics are Closed 6395:The Hopf construction gives circle bundles 3121:{\displaystyle y=\sin(2\eta )\sin \xi _{1}} 3063:{\displaystyle x=\sin(2\eta )\cos \xi _{1}} 410:with circles as fibers, and there are also 6911:"Benjamin H. Smith's Hopf fibration notes" 6896:quaternionic Hopf Fibration, ncatlab.org. 6840:Hopf fibration also found applications in 6411:. This is actually the restriction of the 6277:. Similar patterns of fields are found as 5724:The rotation can be represented using the 4431:The rotation induced by a unit quaternion 4405:This identifies the group of versors with 718:which are a fixed distance from a central 7613:Video of one 30-cell ring of the 600-cell 7517: 7413: 7365: 7326: 7081: 7032: 6807: 6794: 6781: 6775: 6243: 6232: 6219: 6206: 6193: 6148: 6120: 6109: 6096: 6083: 6070: 6051: 6015: 5988: 5975: 5962: 5949: 5874: 5863: 5850: 5837: 5824: 5782: 5780: 5700:-sphere. However, fixing the tip of the 5696:vector) to all possible points on a unit 5621: 5620: 5566: 5565: 5563: 5497: 5488: 5487: 5334: 5333: 5306: 5304: 5201: 5190: 5148: 5121: 5115: 5031: 5010: 5004: 4914: 4905: 4904: 4895: 4882: 4806: 4805: 4803: 4752: 4739: 4632: 4619: 4512: 4499: 4475: 4473: 4390: 4373: 4364: 4355: 4343: 4334: 4325: 4308: 4299: 4290: 4278: 4269: 4260: 4248: 4246: 4168:is one of the circle of versors that fix 4111:is one of the circle of versors that fix 3935: 3929: 3911: 3884: 3875: 3866: 3857: 3848: 3839: 3830: 3822: 3692: 3683: 3674: 3665: 3656: 3647: 3638: 3629: 3617: 3536:-sphere, and this is the Hopf fibration. 3112: 3076: 3054: 3018: 2976: 2803: 2790: 2783: 2764: 2758: 2717: 2704: 2697: 2678: 2672: 2631: 2618: 2611: 2592: 2586: 2545: 2532: 2525: 2506: 2500: 2448: 2435: 2428: 2427: 2423: 2410: 2404: 2365: 2352: 2345: 2344: 2340: 2327: 2321: 2054: 2043: 2033: 2015: 2005: 1981: 1971: 1953: 1943: 1928: 1918: 1897: 1887: 1869: 1859: 1844: 1834: 1813: 1802: 1792: 1774: 1764: 1740: 1730: 1725: 1709: 1704: 1694: 1685: 1590: 1580: 1562: 1552: 1534: 1529: 1519: 1497: 1484: 1472: 1305: 1292: 1276: 1239: 1226: 1213: 1204: 1174: 1158: 1145: 1129: 1110: 1097: 1078: 1065: 1052: 1039: 1030: 841: 837: 836: 833: 803: 784: 771: 762: 741: 735: 687: 633: 620: 607: 601: 576: 563: 550: 544: 519: 506: 493: 487: 462: 449: 436: 430: 218: 210: 198: 192: 179: 173: 6678:The fibers over a circle of latitude on 3814:can be interpreted as a pure quaternion 3543:can either be identified with the group 3471:Geometric interpretation using rotations 976:-sphere can be defined in several ways. 122:. Technically, Hopf found a many-to-one 6883:-sphere, distinct great circles of the 6868: 165:This fiber bundle structure is denoted 56:to a ball. This image shows points on 7321:, Warsaw: Polish Acad. Sci.: 427–440, 3992:In fact, this identifies the group of 3900: 3715:, the quaternions of unit norm, those 6755:, the Riemann sphere is known as the 6675:— a "circle through infinity". 6664: 4965:axis. The fiber for a given point on 1619:-sphere must have the property that 1386:is identified with the subset of all 7: 7617:http://page.math.tu-berlin.de/~gunn/ 7164:IEEE Robotics and Automation Letters 5261:is given by quaternions of the form 3940:{\displaystyle p\mapsto qpq^{*}\,\!} 3711:-sphere is then identified with the 2224:component and in the real component 335:, by identifying the fiber with the 151: 5665:is not topologically equivalent to 4002:, modulo the fact that the versors 2196:cancels with its complex conjugate 7009:"Historical note on fiber bundles" 6728:Hopf proved that the Hopf map has 6718:. Two such linking circles form a 6659:induces a remarkable structure in 6524:. Although one can also define an 4929:which is a continuous function of 4795:, rotates to another unit vector, 856:{\displaystyle \mathbb {R} ^{n+1}} 142:-sphere is mapped from a distinct 25: 5721:-sphere, plus a single rotation. 3467:has a neighborhood of this form. 3410:. Such a fibration is said to be 2245:Since the set of complex numbers 887: = 1. For example, the 74:mimic part of the Hopf fibration. 6485:A similar construction with the 5783: 5202: 5191: 5032: 4365: 4335: 4300: 4270: 4182:rotations which is the range of 3867: 3849: 3831: 3675: 3657: 3639: 3561:In the first approach, a vector 3520:of a point is isomorphic to the 2309:A direct parametrization of the 891:-sphere consists of the points ( 359:. Here each fiber projects to a 134:-sphere such that each distinct 7477:Journal of Geometry and Physics 7007:Friedman, John L. (June 2015). 4027:which fix a given right versor 3996:with the group of rotations of 3599:is interpreted as a quaternion 3219:for any nonzero complex number 367:of a circle of latitude of the 7343:Lyons, David W. (April 2003), 6800: 6787: 6365:is diffeomorphic to a circle. 6361:is diffeomorphic to a sphere, 6171: 6153: 6038: 6020: 5939: 5921: 5912: 5891: 5805: 5787: 5611: 5605: 5590: 5584: 5484: 5478: 5469: 5457: 5451: 5445: 5430: 5424: 5409: 5403: 5388: 5382: 5367: 5361: 5352: 5340: 5327: 5315: 5209: 5175: 5169: 5157: 5140: 5122: 4901: 4875: 4860: 4842: 4833: 4815: 4758: 4732: 4718: 4700: 4692: 4674: 4664: 4646: 4638: 4612: 4598: 4580: 4570: 4552: 4544: 4526: 4518: 4492: 3916: 3099: 3090: 3041: 3032: 3005:{\displaystyle z=\cos(2\eta )} 2999: 2990: 1596: 1509: 1503: 1477: 1420:. (Here, for a complex number 1311: 1269: 1263: 1251: 1248: 1245: 1206: 1180: 1122: 1116: 1090: 1087: 1084: 1032: 815: 764: 701: 689: 626: 613: 569: 556: 512: 499: 455: 442: 185: 1: 7498:10.1016/S0393-0440(02)00121-3 7453:The Topology of Fibre Bundles 7237:; reprinted as article 20 in 6452:quaternionic projective space 3899:Then, as is well-known since 3506:-sphere. The spin group acts 3429:and the corresponding circle 3351:The Hopf fibration defines a 2923:-sphere, and one round trip ( 2186:map to the same point on the 1454:, where the star denotes the 240:meaning that the fiber space 7125:10.1007/978-3-030-28619-4_20 6831:Mosseri & Dandoloff 2001 6450:) multiplication to get the 6427:Quaternionic Hopf fibrations 3783:On the other hand, a vector 7557:Encyclopedia of Mathematics 7432:10.1088/0305-4470/34/47/324 6887:-sphere need not intersect. 6736:. In fact it generates the 6526:octonionic projective plane 5717:-sphere is mapped onto the 5682:-sphere is equivalent to a 5540:, can be given by defining 4462:is given explicitly by the 3374:whose inverse image in the 3318:can be mapped to the ratio 1458:.) Then the Hopf fibration 663:Definition and construction 7674: 7458:Princeton University Press 7250:Cambridge University Press 6934:Kamchatnov, A. M. (1982), 6748:) and has infinite order. 6547:Fibrations between spheres 6519:octonionic projective line 6481:Octonionic Hopf fibrations 6431:Similarly, one can regard 5688:Cartesian coordinate frame 5077:varies, this sweeps out a 4144:to a new plane spanned by 3956:: indeed it is clearly an 3274:one point compactification 2306:of these circular fibers. 401:fibers naturally over the 329:homotopy groups of spheres 7248:, vol. (1841–1853), 7234:10.1080/14786444508562684 6628:Geometry and applications 6357:= {1, −1}. Just as 4021:, and the set of versors 3355:, with bundle projection 3286:). The formula given for 3223:. On any complex line in 2867:runs over the range from 2847:runs over the range from 2302:-sphere is realized as a 757:, consists of the points 7176:10.1109/LRA.2022.3176449 7066:10.1177/0278364909352700 6732:1, and therefore is not 6650:stereographic projection 6457:. In particular, since 6413:tautological line bundle 6409:complex projective space 6265:for arbitrary constants 5512:Since multiplication by 4949:. That is, the image of 4413:matrices (isomorphic to 3483:-dimensional space. The 2887:can take any value from 2162:for some complex number 678:-dimensional sphere, or 403:complex projective space 394:complex coordinate space 343:Stereographic projection 36:stereographic projection 7328:10.4064/fm-25-1-427-440 7314:Fundamenta Mathematicae 6391:Complex Hopf fibrations 5769:Navier–Stokes equations 5103:, is not the antipode, 3530:principal circle bundle 3138:complex projective line 1334:is identified with the 7221:Philosophical Magazine 6923:on September 14, 2016. 6875:This partition of the 6820: 6645: 6419:to the unit sphere in 6256: 6136: 6003: 5634: 5503: 5216: 5049: 4920: 4776: 4396: 4099:. All the quaternions 4062:are real numbers with 3941: 3890: 3698: 3347:Fiber bundle structure 3334:in the Riemann sphere 3282:(obtained by adding a 3251:is diffeomorphic to a 3122: 3064: 3006: 2832: 2746: 2660: 2574: 2478: 2392: 2070: 1637:. If that is so, then 1606: 1318: 1187: 857: 822: 751: 708: 646: 589: 532: 475: 298:. However it is not a 274:(Hopf's map) projects 231: 104:four-dimensional space 75: 63: 7648:Differential geometry 7269:Mathematische Annalen 6850:probabilistic roadmap 6821: 6635: 6612:, fiber bundles with 6378:real projective space 6257: 6137: 6004: 5635: 5536:The final fiber, for 5504: 5217: 5050: 4921: 4777: 4397: 4127:to the same place as 3942: 3891: 3699: 3553:special unitary group 3123: 3065: 3007: 2833: 2747: 2661: 2575: 2479: 2393: 2071: 1607: 1319: 1188: 877: + ⋯+  858: 823: 752: 750:{\displaystyle S^{n}} 709: 707:{\displaystyle (n+1)} 647: 590: 533: 476: 379:Topology and geometry 232: 80:differential topology 69: 50:and then compressing 33: 7537:Computers in Algebra 7528:10.1093/jcde/qwab018 7353:Mathematics Magazine 6774: 6608:As a consequence of 6535:does not fiber over 6505:does not fiber over 6465:, there is a bundle 6368:More generally, the 6351:real projective line 6329:Real Hopf fibrations 6283:magnetohydrodynamics 6147: 6014: 5779: 5562: 5303: 5245:. Thus the fiber of 5114: 5003: 4955:is the point on the 4802: 4472: 4245: 3910: 3821: 3744:, which is equal to 3616: 3485:rotation group SO(3) 3479:-sphere in ordinary 3446:; thus one can take 3175:equivalence relation 3075: 3017: 2975: 2757: 2671: 2585: 2499: 2403: 2320: 1684: 1471: 1203: 1029: 832: 761: 734: 686: 600: 543: 486: 429: 302:fiber bundle, i.e., 280:onto the base space 172: 126:(or "map") from the 7594:by David W. Lyons ( 7490:2003JGP....46..125U 7424:2001JPhA...3410243M 7408:(47): 10243–10252, 7025:2015PhT....68f..11F 6974:. Springer-Verlag. 4121:rotations rotating 3461:, and any point in 2285:is a circle, i.e., 1735: 1714: 1539: 980:Direct construction 954:The Hopf fibration 250:in the total space 211: 124:continuous function 86:(also known as the 7643:Geometric topology 7638:Algebraic topology 7460:(published 1999), 7286:10.1007/BF01457962 7252:, pp. 123–126 6816: 6700:Villarceau circles 6646: 6638:Villarceau circles 6252: 6132: 5999: 5630: 5499: 5212: 5045: 4916: 4772: 4763: 4392: 4381: 3937: 3886: 3694: 3516:by rotations. The 3118: 3060: 3002: 2898:. Every value of 2828: 2742: 2656: 2570: 2474: 2388: 2066: 1721: 1700: 1602: 1525: 1314: 1183: 853: 818: 747: 704: 642: 585: 528: 471: 381:). The loops are 357:Villarceau circles 227: 76: 64: 7467:978-0-691-00548-5 7134:978-3-030-28619-4 7113:Robotics Research 7034:10.1063/PT.3.2799 6986:(§0.26 on page 6) 6981:978-3-540-08158-6 6909:Smith, Benjamin. 6854:automatic control 6753:quantum mechanics 6513:. One can regard 6501:. But the sphere 6317:, including (for 5713:axis. Thus, the 5331: 5330: 5173: 5172: 5107:, the quaternion 5058:is a rotation by 4464:orthogonal matrix 4427:Explicit formulae 4156:. Any quaternion 3950:is a rotation in 3365:-sphere has some 3284:point at infinity 3177:which identifies 2813: 2727: 2641: 2555: 2458: 2375: 2208:: in the complex 2202:in both parts of 1658:lies on the unit 1456:complex conjugate 972:-sphere over the 212: 206: 130:-sphere onto the 16:(Redirected from 7665: 7582: 7581: 7572:"Hopf fibration" 7565: 7552:"Hopf fibration" 7540: 7531: 7521: 7500: 7470: 7448:Steenrod, Norman 7442: 7417: 7415:quant-ph/0108137 7394: 7369: 7349: 7339: 7330: 7304: 7265: 7253: 7236: 7228:(171): 141–145, 7217: 7196: 7195: 7170:(3): 6966–6973. 7161: 7153: 7147: 7146: 7110: 7102: 7096: 7095: 7085: 7045: 7039: 7038: 7036: 7004: 6998: 6993: 6987: 6985: 6964: 6958: 6957: 6956: 6955: 6949: 6943:, archived from 6942: 6931: 6925: 6924: 6922: 6916:. Archived from 6915: 6906: 6900: 6894: 6888: 6886: 6882: 6878: 6873: 6825: 6823: 6822: 6817: 6812: 6811: 6799: 6798: 6786: 6785: 6761:two-level system 6710:circle, both in 6489:yields a bundle 6315:division algebra 6311:projective space 6276: 6270: 6261: 6259: 6258: 6253: 6251: 6250: 6242: 6238: 6237: 6236: 6224: 6223: 6211: 6210: 6198: 6197: 6141: 6139: 6138: 6133: 6128: 6127: 6119: 6115: 6114: 6113: 6101: 6100: 6088: 6087: 6075: 6074: 6056: 6055: 6008: 6006: 6005: 6000: 5998: 5994: 5993: 5992: 5980: 5979: 5967: 5966: 5954: 5953: 5882: 5881: 5873: 5869: 5868: 5867: 5855: 5854: 5842: 5841: 5829: 5828: 5786: 5720: 5716: 5712: 5705: 5699: 5695: 5681: 5674: 5664: 5658: 5648: 5639: 5637: 5636: 5631: 5626: 5625: 5571: 5570: 5554: 5548: 5539: 5532: 5508: 5506: 5505: 5500: 5493: 5492: 5339: 5338: 5332: 5311: 5307: 5295: 5290:, which are the 5289: 5260: 5244: 5228: 5221: 5219: 5218: 5213: 5205: 5194: 5174: 5153: 5149: 5144: 5143: 5106: 5102: 5086: 5076: 5070: 5064: 5054: 5052: 5051: 5046: 5035: 5015: 5014: 4995: 4989: 4970: 4964: 4958: 4954: 4948: 4925: 4923: 4922: 4917: 4910: 4909: 4900: 4899: 4887: 4886: 4811: 4810: 4794: 4790: 4781: 4779: 4778: 4773: 4768: 4767: 4757: 4756: 4744: 4743: 4637: 4636: 4624: 4623: 4517: 4516: 4504: 4503: 4461: 4422: 4412: 4408: 4401: 4399: 4398: 4393: 4386: 4385: 4378: 4377: 4368: 4360: 4359: 4348: 4347: 4338: 4330: 4329: 4313: 4312: 4303: 4295: 4294: 4283: 4282: 4273: 4265: 4264: 4237: 4233: 4187: 4181: 4177: 4173: 4167: 4161: 4155: 4143: 4132: 4126: 4120: 4116: 4110: 4104: 4098: 4082: 4072: 4061: 4055: 4049: 4032: 4026: 4020: 4014: 4007: 4001: 3988: 3955: 3946: 3944: 3943: 3938: 3934: 3933: 3895: 3893: 3892: 3887: 3880: 3879: 3870: 3862: 3861: 3852: 3844: 3843: 3834: 3813: 3807: 3779: 3773: 3743: 3732: 3724: 3710: 3703: 3701: 3700: 3695: 3688: 3687: 3678: 3670: 3669: 3660: 3652: 3651: 3642: 3634: 3633: 3608: 3598: 3592: 3549:unit quaternions 3542: 3535: 3527: 3515: 3505: 3497: 3482: 3478: 3466: 3460: 3445: 3439: 3428: 3422: 3409: 3391: 3377: 3373: 3364: 3360: 3342: 3333: 3317: 3299: 3295: 3291: 3281: 3271: 3254: 3250: 3242: 3236: 3218: 3194: 3172: 3161: 3156:. Equivalently, 3155: 3145: 3127: 3125: 3124: 3119: 3117: 3116: 3069: 3067: 3066: 3061: 3059: 3058: 3011: 3009: 3008: 3003: 2967: 2958: 2951: 2942: 2933: 2926: 2922: 2914: 2907: 2903: 2897: 2890: 2886: 2877: 2870: 2866: 2857: 2850: 2846: 2837: 2835: 2834: 2829: 2818: 2814: 2809: 2808: 2807: 2795: 2794: 2784: 2769: 2768: 2751: 2749: 2748: 2743: 2732: 2728: 2723: 2722: 2721: 2709: 2708: 2698: 2683: 2682: 2665: 2663: 2662: 2657: 2646: 2642: 2637: 2636: 2635: 2623: 2622: 2612: 2597: 2596: 2579: 2577: 2576: 2571: 2560: 2556: 2551: 2550: 2549: 2537: 2536: 2526: 2511: 2510: 2492: 2487:or in Euclidean 2483: 2481: 2480: 2475: 2461: 2460: 2459: 2454: 2453: 2452: 2440: 2439: 2429: 2415: 2414: 2397: 2395: 2394: 2389: 2378: 2377: 2376: 2371: 2370: 2369: 2357: 2356: 2346: 2332: 2331: 2312: 2301: 2297: 2284: 2270: 2264: 2258: 2250: 2241: 2223: 2207: 2201: 2195: 2189: 2185: 2179: 2175: 2167: 2161: 2135: 2117: 2075: 2073: 2072: 2067: 2059: 2058: 2053: 2049: 2048: 2047: 2042: 2038: 2037: 2020: 2019: 2014: 2010: 2009: 1986: 1985: 1980: 1976: 1975: 1958: 1957: 1952: 1948: 1947: 1933: 1932: 1927: 1923: 1922: 1902: 1901: 1896: 1892: 1891: 1874: 1873: 1868: 1864: 1863: 1849: 1848: 1843: 1839: 1838: 1818: 1817: 1812: 1808: 1807: 1806: 1801: 1797: 1796: 1779: 1778: 1773: 1769: 1768: 1745: 1744: 1734: 1729: 1713: 1708: 1699: 1698: 1677: 1671: 1661: 1657: 1636: 1618: 1611: 1609: 1608: 1603: 1595: 1594: 1589: 1585: 1584: 1567: 1566: 1561: 1557: 1556: 1538: 1533: 1524: 1523: 1502: 1501: 1489: 1488: 1463: 1453: 1419: 1407: 1397: 1385: 1379: 1361: 1355: 1333: 1323: 1321: 1320: 1315: 1310: 1309: 1297: 1296: 1281: 1280: 1244: 1243: 1231: 1230: 1218: 1217: 1192: 1190: 1189: 1184: 1179: 1178: 1163: 1162: 1150: 1149: 1134: 1133: 1115: 1114: 1102: 1101: 1083: 1082: 1070: 1069: 1057: 1056: 1044: 1043: 1017: 1011: 1001: 995: 989: 975: 971: 967: 951: = 1. 890: 862: 860: 859: 854: 852: 851: 840: 827: 825: 824: 819: 814: 813: 789: 788: 776: 775: 756: 754: 753: 748: 746: 745: 713: 711: 710: 705: 651: 649: 648: 643: 638: 637: 625: 624: 612: 611: 594: 592: 591: 586: 581: 580: 568: 567: 555: 554: 537: 535: 534: 529: 524: 523: 511: 510: 498: 497: 480: 478: 477: 472: 467: 466: 454: 453: 441: 440: 409: 400: 376: 370: 355:made of linking 350: 333:principal bundle 323: 317: 307: 289: 285: 279: 273: 259: 255: 245: 236: 234: 233: 228: 223: 222: 213: 204: 199: 197: 196: 184: 183: 161: 157: 149: 141: 133: 129: 114:. Discovered by 110:and an ordinary 70:Pairwise linked 61: 55: 49: 43: 21: 7673: 7672: 7668: 7667: 7666: 7664: 7663: 7662: 7658:Homotopy theory 7628: 7627: 7586:Dimensions Math 7570:Rowland, Todd. 7569: 7568: 7550: 7547: 7534: 7503: 7473: 7468: 7446: 7397: 7376:10.2307/3219300 7347: 7342: 7307: 7256: 7238: 7215: 7207: 7204: 7199: 7155: 7154: 7150: 7135: 7104: 7103: 7099: 7047: 7046: 7042: 7006: 7005: 7001: 6994: 6990: 6982: 6966: 6965: 6961: 6953: 6951: 6947: 6940: 6933: 6932: 6928: 6920: 6913: 6908: 6907: 6903: 6895: 6891: 6884: 6880: 6876: 6874: 6870: 6866: 6803: 6790: 6777: 6772: 6771: 6743: 6630: 6610:Adams's theorem 6549: 6483: 6429: 6393: 6337:as a subset of 6331: 6291: 6289:Generalizations 6272: 6266: 6228: 6215: 6202: 6189: 6188: 6184: 6183: 6145: 6144: 6105: 6092: 6079: 6066: 6065: 6061: 6060: 6047: 6012: 6011: 5984: 5971: 5958: 5945: 5887: 5883: 5859: 5846: 5833: 5820: 5819: 5815: 5814: 5777: 5776: 5765: 5763:Fluid mechanics 5718: 5714: 5707: 5701: 5697: 5691: 5679: 5666: 5660: 5650: 5644: 5560: 5559: 5550: 5547: 5541: 5537: 5531: 5513: 5301: 5300: 5291: 5288: 5280: 5262: 5246: 5230: 5226: 5117: 5112: 5111: 5104: 5088: 5082: 5072: 5066: 5059: 5006: 5001: 5000: 4991: 4975: 4966: 4960: 4956: 4950: 4930: 4891: 4878: 4800: 4799: 4792: 4786: 4762: 4761: 4748: 4735: 4721: 4695: 4668: 4667: 4641: 4628: 4615: 4601: 4574: 4573: 4547: 4521: 4508: 4495: 4476: 4470: 4469: 4432: 4429: 4414: 4410: 4406: 4380: 4379: 4369: 4351: 4349: 4339: 4321: 4315: 4314: 4304: 4286: 4284: 4274: 4256: 4249: 4243: 4242: 4235: 4232: 4222: 4212: 4202: 4192: 4183: 4179: 4175: 4169: 4163: 4157: 4145: 4137: 4128: 4122: 4118: 4112: 4106: 4100: 4084: 4074: 4063: 4057: 4051: 4034: 4028: 4022: 4016: 4009: 4003: 3997: 3961: 3951: 3925: 3908: 3907: 3871: 3853: 3835: 3819: 3818: 3809: 3805: 3798: 3791: 3784: 3775: 3772: 3765: 3758: 3751: 3745: 3734: 3726: 3716: 3708: 3679: 3661: 3643: 3625: 3614: 3613: 3600: 3594: 3590: 3583: 3576: 3569: 3562: 3540: 3533: 3525: 3511: 3503: 3495: 3480: 3476: 3473: 3462: 3447: 3441: 3430: 3424: 3418: 3412:locally trivial 3393: 3387: 3378:-sphere can be 3375: 3369: 3362: 3356: 3349: 3341: 3335: 3332: 3325: 3319: 3315: 3308: 3301: 3297: 3293: 3287: 3277: 3272:, which is the 3265: 3259: 3252: 3246: 3238: 3232: 3216: 3206: 3196: 3192: 3185: 3178: 3167: 3157: 3151: 3141: 3134: 3108: 3073: 3072: 3050: 3015: 3014: 2973: 2972: 2966: 2960: 2956: 2950: 2944: 2941: 2935: 2928: 2924: 2920: 2909: 2905: 2899: 2892: 2888: 2885: 2879: 2872: 2868: 2865: 2859: 2852: 2848: 2842: 2799: 2786: 2785: 2779: 2760: 2755: 2754: 2713: 2700: 2699: 2693: 2674: 2669: 2668: 2627: 2614: 2613: 2607: 2588: 2583: 2582: 2541: 2528: 2527: 2521: 2502: 2497: 2496: 2488: 2444: 2431: 2430: 2419: 2406: 2401: 2400: 2361: 2348: 2347: 2336: 2323: 2318: 2317: 2310: 2299: 2286: 2275: 2266: 2260: 2257:| = 1 2252: 2246: 2239: 2233:| − | 2232: 2225: 2222: 2216: 2209: 2203: 2197: 2191: 2187: 2181: 2177: 2174:| = 1 2169: 2163: 2159: 2148: 2137: 2133: 2126: 2119: 2115: 2108: 2097: 2090: 2080: 2029: 2025: 2024: 2001: 1997: 1996: 1995: 1991: 1990: 1967: 1963: 1962: 1939: 1935: 1934: 1914: 1910: 1909: 1883: 1879: 1878: 1855: 1851: 1850: 1830: 1826: 1825: 1788: 1784: 1783: 1760: 1756: 1755: 1754: 1750: 1749: 1736: 1690: 1682: 1681: 1673: 1663: 1659: 1655: 1648: 1638: 1634: 1628:| + | 1627: 1620: 1616: 1576: 1572: 1571: 1548: 1544: 1543: 1515: 1493: 1480: 1469: 1468: 1459: 1421: 1409: 1399: 1387: 1381: 1377: 1370: 1363: 1357: 1353: 1346: 1339: 1329: 1301: 1288: 1272: 1235: 1222: 1209: 1201: 1200: 1170: 1154: 1141: 1125: 1106: 1093: 1074: 1061: 1048: 1035: 1027: 1026: 1020:complex numbers 1013: 1003: 997: 991: 985: 982: 973: 969: 955: 950: 943: 936: 929: 918: 911: 904: 897: 888: 886: 876: 869: 835: 830: 829: 799: 780: 767: 759: 758: 737: 732: 731: 684: 683: 665: 657:Adams's theorem 629: 616: 603: 598: 597: 572: 559: 546: 541: 540: 515: 502: 489: 484: 483: 458: 445: 432: 427: 426: 405: 396: 372: 368: 346: 319: 313: 303: 287: 281: 275: 261: 257: 251: 241: 214: 188: 175: 170: 169: 159: 155: 147: 139: 131: 127: 57: 51: 45: 39: 28: 23: 22: 15: 12: 11: 5: 7671: 7669: 7661: 7660: 7655: 7650: 7645: 7640: 7630: 7629: 7626: 7625: 7620: 7610: 7604: 7599: 7589: 7583: 7566: 7546: 7545:External links 7543: 7542: 7541: 7532: 7512:(3): 836–854. 7501: 7484:(2): 125–150, 7471: 7466: 7444: 7395: 7340: 7305: 7254: 7240:Cayley, Arthur 7209:Cayley, Arthur 7203: 7200: 7198: 7197: 7148: 7133: 7097: 7060:(7): 801–812. 7040: 6999: 6988: 6980: 6959: 6926: 6901: 6889: 6867: 6865: 6862: 6835:Dirac monopole 6827: 6826: 6815: 6810: 6806: 6802: 6797: 6793: 6789: 6784: 6780: 6741: 6738:homotopy group 6734:null-homotopic 6730:Hopf invariant 6704:opposite point 6629: 6626: 6622:exotic spheres 6606: 6605: 6592: 6579: 6566: 6548: 6545: 6482: 6479: 6428: 6425: 6392: 6389: 6330: 6327: 6290: 6287: 6263: 6262: 6249: 6246: 6241: 6235: 6231: 6227: 6222: 6218: 6214: 6209: 6205: 6201: 6196: 6192: 6187: 6182: 6179: 6176: 6173: 6170: 6167: 6164: 6161: 6158: 6155: 6152: 6142: 6131: 6126: 6123: 6118: 6112: 6108: 6104: 6099: 6095: 6091: 6086: 6082: 6078: 6073: 6069: 6064: 6059: 6054: 6050: 6046: 6043: 6040: 6037: 6034: 6031: 6028: 6025: 6022: 6019: 6009: 5997: 5991: 5987: 5983: 5978: 5974: 5970: 5965: 5961: 5957: 5952: 5948: 5944: 5941: 5938: 5935: 5932: 5929: 5926: 5923: 5920: 5917: 5914: 5911: 5908: 5905: 5902: 5899: 5896: 5893: 5890: 5886: 5880: 5877: 5872: 5866: 5862: 5858: 5853: 5849: 5845: 5840: 5836: 5832: 5827: 5823: 5818: 5813: 5810: 5807: 5804: 5801: 5798: 5795: 5792: 5789: 5785: 5764: 5761: 5641: 5640: 5629: 5624: 5619: 5616: 5613: 5610: 5607: 5604: 5601: 5598: 5595: 5592: 5589: 5586: 5583: 5580: 5577: 5574: 5569: 5545: 5517: 5510: 5509: 5496: 5491: 5486: 5483: 5480: 5477: 5474: 5471: 5468: 5465: 5462: 5459: 5456: 5453: 5450: 5447: 5444: 5441: 5438: 5435: 5432: 5429: 5426: 5423: 5420: 5417: 5414: 5411: 5408: 5405: 5402: 5399: 5396: 5393: 5390: 5387: 5384: 5381: 5378: 5375: 5372: 5369: 5366: 5363: 5360: 5357: 5354: 5351: 5348: 5345: 5342: 5337: 5329: 5326: 5323: 5320: 5317: 5314: 5310: 5284: 5266: 5223: 5222: 5211: 5208: 5204: 5200: 5197: 5193: 5189: 5186: 5183: 5180: 5177: 5171: 5168: 5165: 5162: 5159: 5156: 5152: 5147: 5142: 5139: 5136: 5133: 5130: 5127: 5124: 5120: 5056: 5055: 5044: 5041: 5038: 5034: 5030: 5027: 5024: 5021: 5018: 5013: 5009: 4927: 4926: 4913: 4908: 4903: 4898: 4894: 4890: 4885: 4881: 4877: 4874: 4871: 4868: 4865: 4862: 4859: 4856: 4853: 4850: 4847: 4844: 4841: 4838: 4835: 4832: 4829: 4826: 4823: 4820: 4817: 4814: 4809: 4783: 4782: 4771: 4766: 4760: 4755: 4751: 4747: 4742: 4738: 4734: 4731: 4728: 4725: 4722: 4720: 4717: 4714: 4711: 4708: 4705: 4702: 4699: 4696: 4694: 4691: 4688: 4685: 4682: 4679: 4676: 4673: 4670: 4669: 4666: 4663: 4660: 4657: 4654: 4651: 4648: 4645: 4642: 4640: 4635: 4631: 4627: 4622: 4618: 4614: 4611: 4608: 4605: 4602: 4600: 4597: 4594: 4591: 4588: 4585: 4582: 4579: 4576: 4575: 4572: 4569: 4566: 4563: 4560: 4557: 4554: 4551: 4548: 4546: 4543: 4540: 4537: 4534: 4531: 4528: 4525: 4522: 4520: 4515: 4511: 4507: 4502: 4498: 4494: 4491: 4488: 4485: 4482: 4481: 4479: 4428: 4425: 4403: 4402: 4389: 4384: 4376: 4372: 4367: 4363: 4358: 4354: 4350: 4346: 4342: 4337: 4333: 4328: 4324: 4320: 4317: 4316: 4311: 4307: 4302: 4298: 4293: 4289: 4285: 4281: 4277: 4272: 4268: 4263: 4259: 4255: 4254: 4252: 4230: 4220: 4210: 4200: 4033:have the form 3948: 3947: 3932: 3928: 3924: 3921: 3918: 3915: 3903:, the mapping 3897: 3896: 3883: 3878: 3874: 3869: 3865: 3860: 3856: 3851: 3847: 3842: 3838: 3833: 3829: 3826: 3803: 3796: 3789: 3770: 3763: 3756: 3749: 3705: 3704: 3691: 3686: 3682: 3677: 3673: 3668: 3664: 3659: 3655: 3650: 3646: 3641: 3637: 3632: 3628: 3624: 3621: 3588: 3581: 3574: 3567: 3551:, or with the 3472: 3469: 3401:) ≅  3392:and a circle: 3348: 3345: 3339: 3330: 3323: 3313: 3306: 3263: 3257:Riemann sphere 3214: 3204: 3190: 3183: 3133: 3130: 3129: 3128: 3115: 3111: 3107: 3104: 3101: 3098: 3095: 3092: 3089: 3086: 3083: 3080: 3070: 3057: 3053: 3049: 3046: 3043: 3040: 3037: 3034: 3031: 3028: 3025: 3022: 3012: 3001: 2998: 2995: 2992: 2989: 2986: 2983: 2980: 2964: 2948: 2939: 2883: 2863: 2839: 2838: 2827: 2824: 2821: 2817: 2812: 2806: 2802: 2798: 2793: 2789: 2782: 2778: 2775: 2772: 2767: 2763: 2752: 2741: 2738: 2735: 2731: 2726: 2720: 2716: 2712: 2707: 2703: 2696: 2692: 2689: 2686: 2681: 2677: 2666: 2655: 2652: 2649: 2645: 2640: 2634: 2630: 2626: 2621: 2617: 2610: 2606: 2603: 2600: 2595: 2591: 2580: 2569: 2566: 2563: 2559: 2554: 2548: 2544: 2540: 2535: 2531: 2524: 2520: 2517: 2514: 2509: 2505: 2485: 2484: 2473: 2470: 2467: 2464: 2457: 2451: 2447: 2443: 2438: 2434: 2426: 2422: 2418: 2413: 2409: 2398: 2387: 2384: 2381: 2374: 2368: 2364: 2360: 2355: 2351: 2343: 2339: 2335: 2330: 2326: 2304:disjoint union 2237: 2230: 2220: 2214: 2157: 2146: 2131: 2124: 2113: 2106: 2095: 2088: 2077: 2076: 2065: 2062: 2057: 2052: 2046: 2041: 2036: 2032: 2028: 2023: 2018: 2013: 2008: 2004: 2000: 1994: 1989: 1984: 1979: 1974: 1970: 1966: 1961: 1956: 1951: 1946: 1942: 1938: 1931: 1926: 1921: 1917: 1913: 1908: 1905: 1900: 1895: 1890: 1886: 1882: 1877: 1872: 1867: 1862: 1858: 1854: 1847: 1842: 1837: 1833: 1829: 1824: 1821: 1816: 1811: 1805: 1800: 1795: 1791: 1787: 1782: 1777: 1772: 1767: 1763: 1759: 1753: 1748: 1743: 1739: 1733: 1728: 1724: 1720: 1717: 1712: 1707: 1703: 1697: 1693: 1689: 1653: 1646: 1632: 1625: 1613: 1612: 1601: 1598: 1593: 1588: 1583: 1579: 1575: 1570: 1565: 1560: 1555: 1551: 1547: 1542: 1537: 1532: 1528: 1522: 1518: 1514: 1511: 1508: 1505: 1500: 1496: 1492: 1487: 1483: 1479: 1476: 1464:is defined by 1429: + i 1414:| +  1375: 1368: 1351: 1344: 1326: 1325: 1313: 1308: 1304: 1300: 1295: 1291: 1287: 1284: 1279: 1275: 1271: 1268: 1265: 1262: 1259: 1256: 1253: 1250: 1247: 1242: 1238: 1234: 1229: 1225: 1221: 1216: 1212: 1208: 1194: 1193: 1182: 1177: 1173: 1169: 1166: 1161: 1157: 1153: 1148: 1144: 1140: 1137: 1132: 1128: 1124: 1121: 1118: 1113: 1109: 1105: 1100: 1096: 1092: 1089: 1086: 1081: 1077: 1073: 1068: 1064: 1060: 1055: 1051: 1047: 1042: 1038: 1034: 1022:) by writing: 981: 978: 948: 941: 934: 927: 916: 909: 902: 895: 881: 874: 867: 850: 847: 844: 839: 817: 812: 809: 806: 802: 798: 795: 792: 787: 783: 779: 774: 770: 766: 744: 740: 703: 700: 697: 694: 691: 669:natural number 664: 661: 653: 652: 641: 636: 632: 628: 623: 619: 615: 610: 606: 595: 584: 579: 575: 571: 566: 562: 558: 553: 549: 538: 527: 522: 518: 514: 509: 505: 501: 496: 492: 481: 470: 465: 461: 457: 452: 448: 444: 439: 435: 286:(the ordinary 260:-sphere), and 246:(a circle) is 238: 237: 226: 221: 217: 209: 202: 195: 191: 187: 182: 178: 106:) in terms of 94:) describes a 84:Hopf fibration 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 7670: 7659: 7656: 7654: 7653:Fiber bundles 7651: 7649: 7646: 7644: 7641: 7639: 7636: 7635: 7633: 7624: 7621: 7618: 7614: 7611: 7608: 7605: 7603: 7600: 7597: 7593: 7590: 7587: 7584: 7579: 7578: 7573: 7567: 7563: 7559: 7558: 7553: 7549: 7548: 7544: 7538: 7533: 7529: 7525: 7520: 7515: 7511: 7507: 7502: 7499: 7495: 7491: 7487: 7483: 7479: 7478: 7472: 7469: 7463: 7459: 7455: 7454: 7449: 7445: 7441: 7437: 7433: 7429: 7425: 7421: 7416: 7411: 7407: 7403: 7402: 7396: 7393: 7389: 7385: 7381: 7377: 7373: 7368: 7363: 7359: 7355: 7354: 7346: 7341: 7338: 7334: 7329: 7324: 7320: 7316: 7315: 7310: 7306: 7303: 7299: 7295: 7291: 7287: 7283: 7279: 7276:(1), Berlin: 7275: 7271: 7270: 7264: 7259: 7255: 7251: 7247: 7246: 7241: 7235: 7231: 7227: 7223: 7222: 7214: 7210: 7206: 7205: 7201: 7193: 7189: 7185: 7181: 7177: 7173: 7169: 7165: 7160: 7152: 7149: 7144: 7140: 7136: 7130: 7126: 7122: 7118: 7114: 7109: 7101: 7098: 7093: 7089: 7084: 7079: 7075: 7071: 7067: 7063: 7059: 7055: 7051: 7044: 7041: 7035: 7030: 7026: 7022: 7018: 7014: 7013:Physics Today 7010: 7003: 7000: 6997: 6992: 6989: 6983: 6977: 6973: 6969: 6968:Besse, Arthur 6963: 6960: 6950:on 2016-01-28 6946: 6939: 6938: 6930: 6927: 6919: 6912: 6905: 6902: 6899: 6893: 6890: 6872: 6869: 6863: 6861: 6859: 6855: 6851: 6847: 6843: 6838: 6836: 6832: 6813: 6808: 6804: 6795: 6791: 6782: 6778: 6770: 6769: 6768: 6766: 6762: 6758: 6754: 6749: 6747: 6739: 6735: 6731: 6726: 6725: 6721: 6717: 6713: 6709: 6705: 6701: 6697: 6693: 6689: 6685: 6681: 6676: 6674: 6670: 6666: 6662: 6658: 6654: 6651: 6643: 6639: 6634: 6627: 6625: 6623: 6620:to construct 6619: 6615: 6611: 6604: 6600: 6596: 6593: 6591: 6587: 6583: 6580: 6578: 6574: 6570: 6567: 6565: 6561: 6557: 6554: 6553: 6552: 6546: 6544: 6542: 6538: 6534: 6531:, the sphere 6530: 6527: 6523: 6520: 6516: 6512: 6508: 6504: 6500: 6496: 6492: 6488: 6480: 6478: 6476: 6472: 6468: 6464: 6460: 6456: 6453: 6449: 6445: 6442: 6438: 6434: 6426: 6424: 6422: 6418: 6414: 6410: 6406: 6402: 6398: 6390: 6388: 6386: 6382: 6379: 6375: 6371: 6366: 6364: 6360: 6356: 6352: 6348: 6344: 6340: 6336: 6328: 6326: 6324: 6320: 6316: 6312: 6309:-dimensional 6308: 6304: 6300: 6296: 6288: 6286: 6284: 6281:solutions of 6280: 6275: 6269: 6247: 6244: 6239: 6233: 6229: 6225: 6220: 6216: 6212: 6207: 6203: 6199: 6194: 6190: 6185: 6180: 6177: 6174: 6168: 6165: 6162: 6159: 6156: 6150: 6143: 6129: 6124: 6121: 6116: 6110: 6106: 6102: 6097: 6093: 6089: 6084: 6080: 6076: 6071: 6067: 6062: 6057: 6052: 6048: 6044: 6041: 6035: 6032: 6029: 6026: 6023: 6017: 6010: 5995: 5989: 5985: 5981: 5976: 5972: 5968: 5963: 5959: 5955: 5950: 5946: 5942: 5936: 5933: 5930: 5927: 5924: 5918: 5915: 5909: 5906: 5903: 5900: 5897: 5894: 5888: 5884: 5878: 5875: 5870: 5864: 5860: 5856: 5851: 5847: 5843: 5838: 5834: 5830: 5825: 5821: 5816: 5811: 5808: 5802: 5799: 5796: 5793: 5790: 5775: 5774: 5773: 5770: 5762: 5760: 5758: 5754: 5750: 5746: 5742: 5738: 5734: 5730: 5727: 5722: 5710: 5704: 5694: 5689: 5685: 5676: 5673: 5669: 5663: 5657: 5653: 5647: 5627: 5617: 5614: 5608: 5602: 5599: 5596: 5593: 5587: 5581: 5578: 5575: 5572: 5558: 5557: 5556: 5553: 5544: 5534: 5529: 5525: 5521: 5516: 5494: 5481: 5475: 5472: 5466: 5463: 5460: 5454: 5448: 5442: 5439: 5436: 5433: 5427: 5421: 5418: 5415: 5412: 5406: 5400: 5397: 5394: 5391: 5385: 5379: 5376: 5373: 5370: 5364: 5358: 5355: 5349: 5346: 5343: 5324: 5321: 5318: 5312: 5308: 5299: 5298: 5297: 5294: 5287: 5283: 5278: 5274: 5270: 5265: 5258: 5254: 5250: 5242: 5238: 5234: 5206: 5198: 5195: 5187: 5184: 5181: 5178: 5166: 5163: 5160: 5154: 5150: 5145: 5137: 5134: 5131: 5128: 5125: 5118: 5110: 5109: 5108: 5100: 5096: 5092: 5085: 5080: 5075: 5069: 5063: 5042: 5039: 5036: 5028: 5025: 5022: 5019: 5016: 5011: 5007: 4999: 4998: 4997: 4994: 4987: 4983: 4979: 4972: 4969: 4963: 4953: 4946: 4942: 4938: 4934: 4911: 4896: 4892: 4888: 4883: 4879: 4872: 4869: 4866: 4863: 4857: 4854: 4851: 4848: 4845: 4839: 4836: 4830: 4827: 4824: 4821: 4818: 4812: 4798: 4797: 4796: 4789: 4769: 4764: 4753: 4749: 4745: 4740: 4736: 4729: 4726: 4723: 4715: 4712: 4709: 4706: 4703: 4697: 4689: 4686: 4683: 4680: 4677: 4671: 4661: 4658: 4655: 4652: 4649: 4643: 4633: 4629: 4625: 4620: 4616: 4609: 4606: 4603: 4595: 4592: 4589: 4586: 4583: 4577: 4567: 4564: 4561: 4558: 4555: 4549: 4541: 4538: 4535: 4532: 4529: 4523: 4513: 4509: 4505: 4500: 4496: 4489: 4486: 4483: 4477: 4468: 4467: 4466: 4465: 4460: 4457: 4453: 4450: 4446: 4443: 4439: 4435: 4426: 4424: 4421: 4417: 4387: 4382: 4374: 4370: 4361: 4356: 4352: 4344: 4340: 4331: 4326: 4322: 4318: 4309: 4305: 4296: 4291: 4287: 4279: 4275: 4266: 4261: 4257: 4250: 4241: 4240: 4239: 4229: 4226: 4219: 4216: 4209: 4206: 4199: 4195: 4189: 4186: 4172: 4166: 4160: 4153: 4149: 4141: 4134: 4131: 4125: 4115: 4109: 4103: 4097: 4094: 4091: 4087: 4081: 4077: 4070: 4066: 4060: 4054: 4048: 4045: 4041: 4037: 4031: 4025: 4019: 4013: 4006: 4000: 3995: 3990: 3986: 3982: 3979: 3975: 3972: 3969: 3965: 3959: 3954: 3930: 3926: 3922: 3919: 3913: 3906: 3905: 3904: 3902: 3901:Cayley (1845) 3881: 3876: 3872: 3863: 3858: 3854: 3845: 3840: 3836: 3827: 3824: 3817: 3816: 3815: 3812: 3802: 3795: 3788: 3781: 3778: 3769: 3762: 3755: 3748: 3742: 3738: 3730: 3723: 3719: 3714: 3689: 3684: 3680: 3671: 3666: 3662: 3653: 3648: 3644: 3635: 3630: 3626: 3622: 3619: 3612: 3611: 3610: 3607: 3603: 3597: 3587: 3580: 3573: 3566: 3559: 3557: 3554: 3550: 3546: 3537: 3531: 3528:-sphere is a 3523: 3519: 3514: 3509: 3501: 3500:diffeomorphic 3494: 3490: 3486: 3470: 3468: 3465: 3458: 3454: 3450: 3444: 3437: 3433: 3427: 3421: 3415: 3413: 3408: 3404: 3400: 3396: 3390: 3385: 3381: 3372: 3368: 3359: 3354: 3346: 3344: 3338: 3329: 3322: 3312: 3305: 3290: 3285: 3280: 3275: 3269: 3262: 3258: 3249: 3244: 3241: 3235: 3230: 3226: 3222: 3213: 3210: 3203: 3200: 3189: 3182: 3176: 3170: 3165: 3160: 3154: 3149: 3144: 3139: 3131: 3113: 3109: 3105: 3102: 3096: 3093: 3087: 3084: 3081: 3078: 3071: 3055: 3051: 3047: 3044: 3038: 3035: 3029: 3026: 3023: 3020: 3013: 2996: 2993: 2987: 2984: 2981: 2978: 2971: 2970: 2969: 2963: 2953: 2947: 2938: 2932: 2918: 2912: 2902: 2896: 2882: 2876: 2862: 2855: 2845: 2825: 2822: 2819: 2815: 2810: 2804: 2800: 2796: 2791: 2787: 2780: 2776: 2773: 2770: 2765: 2761: 2753: 2739: 2736: 2733: 2729: 2724: 2718: 2714: 2710: 2705: 2701: 2694: 2690: 2687: 2684: 2679: 2675: 2667: 2653: 2650: 2647: 2643: 2638: 2632: 2628: 2624: 2619: 2615: 2608: 2604: 2601: 2598: 2593: 2589: 2581: 2567: 2564: 2561: 2557: 2552: 2546: 2542: 2538: 2533: 2529: 2522: 2518: 2515: 2512: 2507: 2503: 2495: 2494: 2493: 2491: 2471: 2468: 2465: 2462: 2455: 2449: 2445: 2441: 2436: 2432: 2424: 2420: 2416: 2411: 2407: 2399: 2385: 2382: 2379: 2372: 2366: 2362: 2358: 2353: 2349: 2341: 2337: 2333: 2328: 2324: 2316: 2315: 2314: 2307: 2305: 2296: 2293: ≅  2292: 2289: 2282: 2278: 2274: 2273:inverse image 2269: 2263: 2256: 2249: 2243: 2236: 2229: 2219: 2213: 2206: 2200: 2194: 2184: 2173: 2166: 2156: 2152: 2145: 2141: 2130: 2123: 2112: 2105: 2101: 2094: 2087: 2083: 2063: 2060: 2055: 2050: 2044: 2039: 2034: 2030: 2026: 2021: 2016: 2011: 2006: 2002: 1998: 1992: 1987: 1982: 1977: 1972: 1968: 1964: 1959: 1954: 1949: 1944: 1940: 1936: 1929: 1924: 1919: 1915: 1911: 1906: 1903: 1898: 1893: 1888: 1884: 1880: 1875: 1870: 1865: 1860: 1856: 1852: 1845: 1840: 1835: 1831: 1827: 1822: 1819: 1814: 1809: 1803: 1798: 1793: 1789: 1785: 1780: 1775: 1770: 1765: 1761: 1757: 1751: 1746: 1741: 1737: 1731: 1726: 1722: 1718: 1715: 1710: 1705: 1701: 1695: 1691: 1687: 1680: 1679: 1678: 1676: 1670: 1666: 1652: 1645: 1641: 1631: 1624: 1599: 1591: 1586: 1581: 1577: 1573: 1568: 1563: 1558: 1553: 1549: 1545: 1540: 1535: 1530: 1526: 1520: 1516: 1512: 1506: 1498: 1494: 1490: 1485: 1481: 1474: 1467: 1466: 1465: 1462: 1457: 1452: 1449: +  1448: 1444: 1440: 1436: 1432: 1428: 1424: 1417: 1413: 1406: 1402: 1395: 1391: 1384: 1374: 1367: 1360: 1350: 1343: 1337: 1332: 1306: 1302: 1298: 1293: 1289: 1285: 1282: 1277: 1273: 1266: 1260: 1257: 1254: 1240: 1236: 1232: 1227: 1223: 1219: 1214: 1210: 1199: 1198: 1197: 1175: 1171: 1167: 1164: 1159: 1155: 1151: 1146: 1142: 1138: 1135: 1130: 1126: 1119: 1111: 1107: 1103: 1098: 1094: 1079: 1075: 1071: 1066: 1062: 1058: 1053: 1049: 1045: 1040: 1036: 1025: 1024: 1023: 1021: 1016: 1010: 1006: 1000: 994: 988: 979: 977: 966: 962: 958: 952: 947: 944: +  940: 937: +  933: 930: +  926: 922: 915: 908: 901: 894: 884: 880: 873: 870: +  866: 848: 845: 842: 810: 807: 804: 800: 796: 793: 790: 785: 781: 777: 772: 768: 742: 738: 729: 725: 721: 717: 714:-dimensional 698: 695: 692: 681: 677: 673: 670: 662: 660: 658: 639: 634: 630: 621: 617: 608: 604: 596: 582: 577: 573: 564: 560: 551: 547: 539: 525: 520: 516: 507: 503: 494: 490: 482: 468: 463: 459: 450: 446: 437: 433: 425: 424: 423: 421: 417: 413: 408: 404: 399: 395: 390: 388: 384: 380: 375: 366: 365:inverse image 362: 358: 354: 349: 344: 340: 338: 334: 330: 325: 322: 316: 312:a product of 311: 306: 301: 297: 296:product space 293: 284: 278: 272: 268: 265: :  264: 254: 249: 244: 224: 219: 215: 207: 200: 193: 189: 180: 176: 168: 167: 166: 163: 153: 145: 137: 125: 121: 117: 113: 109: 105: 101: 97: 93: 89: 85: 81: 73: 68: 60: 54: 48: 42: 37: 32: 19: 7575: 7555: 7536: 7519:2003.09236v2 7509: 7505: 7481: 7475: 7452: 7405: 7399: 7360:(2): 87–98, 7357: 7351: 7318: 7312: 7273: 7267: 7244: 7225: 7219: 7167: 7163: 7151: 7116: 7112: 7100: 7057: 7053: 7043: 7016: 7012: 7002: 6991: 6971: 6962: 6952:, retrieved 6945:the original 6936: 6929: 6918:the original 6904: 6892: 6871: 6839: 6828: 6757:Bloch sphere 6750: 6745: 6727: 6723: 6715: 6711: 6707: 6695: 6687: 6679: 6677: 6672: 6668: 6660: 6656: 6652: 6647: 6641: 6607: 6602: 6598: 6594: 6589: 6585: 6581: 6576: 6572: 6568: 6563: 6559: 6555: 6550: 6540: 6536: 6532: 6528: 6521: 6514: 6510: 6506: 6502: 6498: 6494: 6490: 6484: 6474: 6470: 6466: 6462: 6458: 6454: 6447: 6443: 6441:quaternionic 6436: 6435:as lying in 6432: 6430: 6420: 6416: 6404: 6400: 6396: 6394: 6384: 6380: 6376:fibers over 6373: 6369: 6367: 6362: 6358: 6354: 6346: 6342: 6338: 6334: 6332: 6318: 6306: 6302: 6298: 6294: 6292: 6273: 6267: 6264: 5766: 5756: 5752: 5748: 5744: 5736: 5732: 5728: 5726:Euler angles 5723: 5708: 5702: 5692: 5677: 5671: 5667: 5661: 5655: 5651: 5645: 5642: 5555:, producing 5551: 5542: 5535: 5527: 5523: 5519: 5514: 5511: 5292: 5285: 5281: 5276: 5272: 5268: 5263: 5256: 5252: 5248: 5240: 5236: 5232: 5224: 5098: 5094: 5090: 5083: 5079:great circle 5073: 5067: 5061: 5057: 4992: 4985: 4981: 4977: 4973: 4967: 4961: 4951: 4944: 4940: 4936: 4932: 4928: 4787: 4784: 4458: 4455: 4451: 4448: 4444: 4441: 4437: 4433: 4430: 4419: 4415: 4404: 4227: 4224: 4217: 4214: 4207: 4204: 4197: 4193: 4190: 4184: 4170: 4164: 4158: 4151: 4147: 4139: 4135: 4129: 4123: 4113: 4107: 4101: 4095: 4092: 4089: 4085: 4079: 4075: 4068: 4064: 4058: 4052: 4046: 4043: 4039: 4035: 4029: 4023: 4017: 4011: 4004: 3998: 3991: 3984: 3980: 3977: 3973: 3970: 3967: 3963: 3952: 3949: 3898: 3810: 3800: 3793: 3786: 3782: 3776: 3767: 3760: 3753: 3746: 3740: 3736: 3728: 3721: 3717: 3706: 3605: 3601: 3595: 3585: 3578: 3571: 3564: 3560: 3538: 3522:circle group 3512: 3508:transitively 3489:double cover 3474: 3463: 3456: 3452: 3448: 3442: 3435: 3431: 3425: 3419: 3416: 3406: 3402: 3398: 3394: 3388: 3370: 3367:neighborhood 3357: 3353:fiber bundle 3350: 3336: 3327: 3320: 3310: 3303: 3288: 3278: 3267: 3260: 3247: 3245: 3239: 3233: 3229:quotient map 3224: 3220: 3211: 3208: 3201: 3198: 3187: 3180: 3168: 3158: 3152: 3142: 3135: 2961: 2954: 2945: 2936: 2934:) of either 2930: 2910: 2900: 2894: 2880: 2874: 2860: 2853: 2843: 2840: 2489: 2486: 2308: 2294: 2290: 2287: 2280: 2276: 2267: 2261: 2254: 2247: 2244: 2234: 2227: 2217: 2211: 2204: 2198: 2192: 2182: 2171: 2164: 2154: 2150: 2143: 2139: 2128: 2121: 2110: 2103: 2099: 2092: 2085: 2081: 2078: 1674: 1668: 1664: 1650: 1643: 1639: 1629: 1622: 1614: 1460: 1450: 1446: 1442: 1438: 1434: 1430: 1426: 1422: 1415: 1411: 1404: 1400: 1393: 1389: 1382: 1372: 1365: 1358: 1348: 1341: 1330: 1327: 1195: 1018:denotes the 1014: 1008: 1004: 998: 992: 986: 983: 964: 960: 956: 953: 945: 938: 931: 924: 920: 913: 906: 899: 892: 882: 878: 871: 864: 727: 675: 671: 666: 654: 416:quaternionic 406: 397: 391: 383:homeomorphic 373: 347: 341: 337:circle group 326: 320: 314: 309: 304: 299: 282: 276: 270: 266: 262: 252: 242: 239: 164: 154:). Thus the 144:great circle 135: 120:fiber bundle 91: 87: 83: 77: 58: 52: 46: 40: 7309:Hopf, Heinz 7280:: 637–665, 7258:Hopf, Heinz 6618:John Milnor 6601:with fiber 6588:with fiber 6575:with fiber 6562:with fiber 6539:with fiber 6509:with fiber 6497:with fiber 6473:with fiber 6383:with fiber 6353:with fiber 5065:around the 4178:-sphere of 3609:by writing 3296:-sphere in 2298:. Thus the 2136:must equal 1662:-sphere in 100:hypersphere 88:Hopf bundle 18:Hopf bundle 7632:Categories 7456:, PMS 14, 7367:2212.01642 7202:References 6954:2011-08-03 6858:quadrotors 6665:Lyons 2003 5684:quaternion 5538:(0, 0, −1) 5225:will send 5105:(0, 0, −1) 3780:as above. 3725:for which 3518:stabilizer 3493:spin group 3380:identified 2917:flat torus 1635:| = 1 1408:such that 1378:| = 1 1362:such that 420:octonionic 116:Heinz Hopf 7577:MathWorld 7562:EMS Press 7440:119462869 7384:0025-570X 7337:0016-2736 7302:123533891 7294:0025-5831 7192:249550496 7184:2377-3766 7143:195852176 7074:0278-3649 7019:(6): 11. 6801:→ 6788:↪ 6720:Hopf link 6487:octonions 6349:over the 6323:octonions 6321:= 1) the 6245:− 6151:ρ 6122:− 6045:− 5969:− 5956:− 5895:− 5876:− 5609:θ 5603:⁡ 5597:− 5588:θ 5582:⁡ 5549:to equal 5482:θ 5476:⁡ 5449:θ 5443:⁡ 5428:θ 5422:⁡ 5407:θ 5401:⁡ 5392:− 5386:θ 5380:⁡ 5365:θ 5359:⁡ 5227:(0, 0, 1) 5188:− 5071:axis. As 5043:θ 5040:⁡ 5026:θ 5023:⁡ 5012:θ 4870:− 4852:− 4727:− 4684:− 4656:− 4607:− 4536:− 4487:− 4362:− 4319:− 4234:with the 3931:∗ 3917:↦ 3532:over the 3382:with the 3148:subspaces 3110:ξ 3106:⁡ 3097:η 3088:⁡ 3052:ξ 3048:⁡ 3039:η 3030:⁡ 2997:η 2988:⁡ 2904:, except 2826:η 2823:⁡ 2801:ξ 2797:− 2788:ξ 2777:⁡ 2740:η 2737:⁡ 2715:ξ 2711:− 2702:ξ 2691:⁡ 2654:η 2651:⁡ 2629:ξ 2616:ξ 2605:⁡ 2568:η 2565:⁡ 2543:ξ 2530:ξ 2519:⁡ 2469:η 2466:⁡ 2446:ξ 2442:− 2433:ξ 2386:η 2383:⁡ 2363:ξ 2350:ξ 1904:− 1781:− 1732:∗ 1716:⋅ 1711:∗ 1569:− 1536:∗ 1437:| = 1249:↔ 1088:↔ 984:Identify 794:… 730:-sphere, 627:→ 614:↪ 570:→ 557:↪ 513:→ 500:↪ 456:→ 443:↪ 186:↪ 162:-sphere. 152:Hopf 1931 150:-sphere ( 7450:(1951), 7278:Springer 7260:(1931), 7242:(1889), 7211:(1845), 7092:20607113 6970:(1978). 6848:for the 6842:robotics 6399: : 6372:-sphere 5546:(0,0,−1) 4238:matrix: 4162:, where 4105:, where 4050:, where 3960:, since 3958:isometry 3733:, where 3164:quotient 1445: = 1425: = 680:n-sphere 667:For any 310:globally 248:embedded 201:→ 96:3-sphere 92:Hopf map 72:keyrings 7564:, 2001 7486:Bibcode 7420:Bibcode 7392:3219300 7083:2896220 7021:Bibcode 6714:and in 6692:toruses 6682:form a 6614:spheres 6517:as the 6279:soliton 5741:3-torus 5296:points 4793:(0,0,1) 4133:does). 3994:versors 3713:versors 3541:Spin(3) 3502:to the 3496:Spin(3) 3384:product 3173:by the 3162:is the 2919:in the 2118:, then 1338:of all 1012:(where 968:of the 912:,  905:,  898:,  387:circles 308:is not 300:trivial 292:locally 146:of the 138:of the 108:circles 7464:  7438:  7390:  7382:  7335:  7300:  7292:  7190:  7182:  7141:  7131:  7090:  7080:  7072:  6978:  5755:) and 5735:, and 4791:axis, 3491:, the 3487:has a 2878:, and 2841:Where 2271:, the 2153:  2142:  1441:  1380:, and 1336:subset 724:origin 418:, and 361:circle 205:  112:sphere 82:, the 7615:from 7514:arXiv 7436:S2CID 7410:arXiv 7388:JSTOR 7362:arXiv 7348:(PDF) 7298:S2CID 7216:(PDF) 7188:S2CID 7139:S2CID 6948:(PDF) 6941:(PDF) 6921:(PDF) 6914:(PDF) 6864:Notes 6846:SO(3) 6765:qubit 6708:every 6684:torus 6415:over 6407:over 4407:SU(2) 3978:q p p 3968:q p q 3964:q p q 3731:| = 1 3556:SU(2) 3545:Sp(1) 3440:from 3423:from 3270:∪ {∞} 3237:over 3195:with 2251:with 2168:with 1371:| + | 1328:Thus 1002:with 990:with 923:with 919:) in 863:with 720:point 716:space 674:, an 256:(the 136:point 7462:ISBN 7380:ISSN 7333:ISSN 7290:ISSN 7180:ISSN 7129:ISBN 7088:PMID 7070:ISSN 6976:ISBN 6271:and 5743:of ( 5649:and 4180:180° 4138:{1, 4119:180° 4056:and 4008:and 3966:| = 3774:for 3739:| = 3707:The 3171:\{0} 2908:and 2098:) = 1196:and 996:and 412:real 353:tori 318:and 7596:PDF 7524:doi 7494:doi 7428:doi 7372:doi 7323:doi 7282:doi 7274:104 7230:doi 7172:doi 7121:doi 7078:PMC 7062:doi 7029:doi 6856:of 6763:or 6751:In 6722:in 6694:in 6686:in 6640:in 5600:sin 5579:cos 5473:sin 5440:sin 5419:cos 5398:cos 5377:sin 5356:cos 5229:to 5081:of 5037:sin 5020:cos 4990:in 4423:). 4411:2×2 4236:2×2 4185:ωkω 4088:to 4071:= 1 3983:= | 3971:q p 3808:in 3741:q q 3593:in 3547:of 3510:on 3386:of 3276:of 3166:of 3150:of 3103:sin 3085:sin 3045:cos 3027:sin 2985:cos 2943:or 2927:to 2891:to 2871:to 2851:to 2820:cos 2774:sin 2734:cos 2688:cos 2648:sin 2602:sin 2562:sin 2516:cos 2463:cos 2380:sin 2265:in 1433:, | 1418:= 1 1398:in 1356:in 885:+ 1 828:in 655:By 102:in 98:(a 90:or 78:In 44:to 38:of 7634:: 7574:. 7560:, 7554:, 7522:. 7508:. 7492:, 7482:46 7480:, 7434:, 7426:, 7418:, 7406:34 7404:, 7386:, 7378:, 7370:, 7358:76 7356:, 7350:, 7331:, 7319:25 7317:, 7296:, 7288:, 7272:, 7266:, 7226:26 7224:, 7218:, 7186:. 7178:. 7166:. 7162:. 7137:. 7127:. 7117:10 7111:. 7086:. 7076:. 7068:. 7058:29 7056:. 7052:. 7027:. 7017:68 7015:. 7011:. 6860:. 6837:. 6655:→ 6624:. 6597:→ 6584:→ 6571:→ 6558:→ 6543:. 6537:OP 6529:OP 6522:OP 6493:→ 6477:. 6469:→ 6463:HP 6461:= 6455:HP 6423:. 6417:CP 6405:CP 6403:→ 6387:. 6381:RP 6363:RP 6359:CP 6347:RP 6345:→ 6325:. 6303:CP 6301:→ 6297:: 6285:: 5759:. 5751:, 5747:, 5731:, 5675:. 5275:, 5271:, 5255:, 5251:, 5239:, 5235:, 5097:, 5093:, 4984:, 4980:, 4943:, 4939:, 4935:, 4454:+ 4447:+ 4440:+ 4436:= 4418:× 4223:+ 4213:+ 4203:+ 4196:= 4188:. 4159:ωq 4152:ωk 4150:, 4102:ωq 4078:= 4067:+ 4042:+ 4038:= 3976:= 3799:, 3792:, 3766:+ 3759:+ 3752:+ 3720:∈ 3604:∈ 3584:, 3577:, 3570:, 3558:. 3498:, 3455:\{ 3451:= 3414:. 3405:× 3343:. 3309:, 3266:= 3248:CP 3243:. 3240:CP 3207:, 3186:, 3159:CP 3143:CP 3140:, 2968:. 2913:/2 2858:, 2856:/2 2242:. 2149:, 2127:, 2109:, 2091:, 1667:× 1649:, 1392:, 1347:, 1007:× 963:→ 959:: 622:15 414:, 407:CP 389:. 339:. 294:a 269:→ 7619:. 7598:) 7580:. 7530:. 7526:: 7516:: 7510:8 7496:: 7488:: 7443:. 7430:: 7422:: 7412:: 7374:: 7364:: 7325:: 7284:: 7232:: 7194:. 7174:: 7168:7 7145:. 7123:: 7094:. 7064:: 7037:. 7031:: 7023:: 6984:. 6885:3 6881:2 6877:3 6829:( 6814:. 6809:4 6805:S 6796:7 6792:S 6783:3 6779:S 6746:S 6744:( 6742:3 6740:π 6724:R 6716:S 6712:R 6696:R 6688:S 6680:S 6673:R 6669:R 6661:R 6657:R 6653:S 6644:. 6642:R 6603:S 6599:S 6595:S 6590:S 6586:S 6582:S 6577:S 6573:S 6569:S 6564:S 6560:S 6556:S 6541:S 6533:S 6515:S 6511:S 6507:S 6503:S 6499:S 6495:S 6491:S 6475:S 6471:S 6467:S 6459:S 6448:S 6444:n 6439:( 6437:H 6433:S 6421:C 6401:S 6397:p 6385:S 6374:S 6370:n 6355:S 6343:S 6339:R 6335:S 6319:n 6307:n 6299:S 6295:p 6274:B 6268:A 6248:1 6240:) 6234:2 6230:z 6226:+ 6221:2 6217:y 6213:+ 6208:2 6204:x 6200:+ 6195:2 6191:a 6186:( 6181:B 6178:3 6175:= 6172:) 6169:z 6166:, 6163:y 6160:, 6157:x 6154:( 6130:, 6125:3 6117:) 6111:2 6107:z 6103:+ 6098:2 6094:y 6090:+ 6085:2 6081:x 6077:+ 6072:2 6068:a 6063:( 6058:B 6053:2 6049:A 6042:= 6039:) 6036:z 6033:, 6030:y 6027:, 6024:x 6021:( 6018:p 5996:) 5990:2 5986:z 5982:+ 5977:2 5973:y 5964:2 5960:x 5951:2 5947:a 5943:, 5940:) 5937:z 5934:y 5931:+ 5928:x 5925:a 5922:( 5919:2 5916:, 5913:) 5910:z 5907:x 5904:+ 5901:y 5898:a 5892:( 5889:2 5885:( 5879:2 5871:) 5865:2 5861:z 5857:+ 5852:2 5848:y 5844:+ 5839:2 5835:x 5831:+ 5826:2 5822:a 5817:( 5812:A 5809:= 5806:) 5803:z 5800:, 5797:y 5794:, 5791:x 5788:( 5784:v 5757:S 5753:ψ 5749:φ 5745:θ 5737:ψ 5733:φ 5729:θ 5719:2 5715:3 5711:- 5709:z 5703:z 5698:2 5693:z 5680:3 5672:S 5670:× 5668:S 5662:S 5656:S 5654:× 5652:S 5646:S 5628:, 5623:) 5618:0 5615:, 5612:) 5606:( 5594:, 5591:) 5585:( 5576:, 5573:0 5568:( 5552:i 5543:q 5530:) 5528:c 5526:, 5524:b 5522:, 5520:a 5518:( 5515:q 5495:. 5490:) 5485:) 5479:( 5470:) 5467:c 5464:+ 5461:1 5458:( 5455:, 5452:) 5446:( 5437:b 5434:+ 5431:) 5425:( 5416:a 5413:, 5410:) 5404:( 5395:b 5389:) 5383:( 5374:a 5371:, 5368:) 5362:( 5353:) 5350:c 5347:+ 5344:1 5341:( 5336:( 5328:) 5325:c 5322:+ 5319:1 5316:( 5313:2 5309:1 5293:S 5286:θ 5282:q 5279:) 5277:c 5273:b 5269:a 5267:( 5264:q 5259:) 5257:c 5253:b 5249:a 5247:( 5243:) 5241:c 5237:b 5233:a 5231:( 5210:) 5207:a 5203:j 5199:+ 5196:b 5192:i 5185:c 5182:+ 5179:1 5176:( 5170:) 5167:c 5164:+ 5161:1 5158:( 5155:2 5151:1 5146:= 5141:) 5138:c 5135:, 5132:b 5129:, 5126:a 5123:( 5119:q 5101:) 5099:c 5095:b 5091:a 5089:( 5084:S 5074:θ 5068:z 5062:θ 5060:2 5033:k 5029:+ 5017:= 5008:q 4993:S 4988:) 4986:c 4982:b 4978:a 4976:( 4968:S 4962:z 4957:2 4952:q 4947:) 4945:z 4941:y 4937:x 4933:w 4931:( 4912:, 4907:) 4902:) 4897:2 4893:y 4889:+ 4884:2 4880:x 4876:( 4873:2 4867:1 4864:, 4861:) 4858:x 4855:w 4849:z 4846:y 4843:( 4840:2 4837:, 4834:) 4831:y 4828:w 4825:+ 4822:z 4819:x 4816:( 4813:2 4808:( 4788:z 4770:. 4765:] 4759:) 4754:2 4750:y 4746:+ 4741:2 4737:x 4733:( 4730:2 4724:1 4719:) 4716:x 4713:w 4710:+ 4707:z 4704:y 4701:( 4698:2 4693:) 4690:y 4687:w 4681:z 4678:x 4675:( 4672:2 4665:) 4662:x 4659:w 4653:z 4650:y 4647:( 4644:2 4639:) 4634:2 4630:z 4626:+ 4621:2 4617:x 4613:( 4610:2 4604:1 4599:) 4596:z 4593:w 4590:+ 4587:y 4584:x 4581:( 4578:2 4571:) 4568:y 4565:w 4562:+ 4559:z 4556:x 4553:( 4550:2 4545:) 4542:z 4539:w 4533:y 4530:x 4527:( 4524:2 4519:) 4514:2 4510:z 4506:+ 4501:2 4497:y 4493:( 4490:2 4484:1 4478:[ 4459:z 4456:k 4452:y 4449:j 4445:x 4442:i 4438:w 4434:q 4420:R 4416:C 4388:. 4383:] 4375:2 4371:x 4366:i 4357:1 4353:x 4345:4 4341:x 4336:i 4332:+ 4327:3 4323:x 4310:4 4306:x 4301:i 4297:+ 4292:3 4288:x 4280:2 4276:x 4271:i 4267:+ 4262:1 4258:x 4251:[ 4231:4 4228:x 4225:k 4221:3 4218:x 4215:j 4211:2 4208:x 4205:i 4201:1 4198:x 4194:q 4176:2 4171:k 4165:q 4154:} 4148:ω 4146:{ 4142:} 4140:k 4130:ω 4124:k 4114:k 4108:q 4096:ω 4093:k 4090:ω 4086:ω 4080:k 4076:p 4069:v 4065:u 4059:v 4053:u 4047:p 4044:v 4040:u 4036:q 4030:p 4024:q 4018:S 4012:q 4010:− 4005:q 3999:R 3987:| 3985:p 3981:q 3974:q 3962:| 3953:R 3927:q 3923:p 3920:q 3914:p 3882:. 3877:3 3873:y 3868:k 3864:+ 3859:2 3855:y 3850:j 3846:+ 3841:1 3837:y 3832:i 3828:= 3825:p 3811:R 3806:) 3804:3 3801:y 3797:2 3794:y 3790:1 3787:y 3785:( 3777:q 3771:4 3768:x 3764:3 3761:x 3757:2 3754:x 3750:1 3747:x 3737:q 3735:| 3729:q 3727:| 3722:H 3718:q 3709:3 3690:. 3685:4 3681:x 3676:k 3672:+ 3667:3 3663:x 3658:j 3654:+ 3649:2 3645:x 3640:i 3636:+ 3631:1 3627:x 3623:= 3620:q 3606:H 3602:q 3596:R 3591:) 3589:4 3586:x 3582:3 3579:x 3575:2 3572:x 3568:1 3565:x 3563:( 3534:2 3526:3 3513:S 3504:3 3481:3 3477:2 3464:S 3459:} 3457:m 3453:S 3449:U 3443:S 3438:) 3436:m 3434:( 3432:p 3426:S 3420:m 3407:S 3403:U 3399:U 3397:( 3395:p 3389:U 3376:3 3371:U 3363:2 3358:p 3340:∞ 3337:C 3331:0 3328:z 3326:/ 3324:1 3321:z 3316:) 3314:1 3311:z 3307:0 3304:z 3302:( 3298:3 3294:2 3289:p 3279:C 3268:C 3264:∞ 3261:C 3253:2 3234:S 3225:C 3221:λ 3217:) 3215:1 3212:z 3209:λ 3205:0 3202:z 3199:λ 3197:( 3193:) 3191:1 3188:z 3184:0 3181:z 3179:( 3169:C 3153:C 3114:1 3100:) 3094:2 3091:( 3082:= 3079:y 3056:1 3042:) 3036:2 3033:( 3024:= 3021:x 3000:) 2994:2 2991:( 2982:= 2979:z 2965:2 2962:ξ 2957:2 2949:2 2946:ξ 2940:1 2937:ξ 2931:π 2929:4 2925:0 2921:3 2911:π 2906:0 2901:η 2895:π 2893:4 2889:0 2884:2 2881:ξ 2875:π 2873:2 2869:0 2864:1 2861:ξ 2854:π 2849:0 2844:η 2816:) 2811:2 2805:1 2792:2 2781:( 2771:= 2766:4 2762:x 2730:) 2725:2 2719:1 2706:2 2695:( 2685:= 2680:3 2676:x 2644:) 2639:2 2633:2 2625:+ 2620:1 2609:( 2599:= 2594:2 2590:x 2558:) 2553:2 2547:2 2539:+ 2534:1 2523:( 2513:= 2508:1 2504:x 2490:R 2472:. 2456:2 2450:1 2437:2 2425:i 2421:e 2417:= 2412:1 2408:z 2373:2 2367:2 2359:+ 2354:1 2342:i 2338:e 2334:= 2329:0 2325:z 2311:3 2300:3 2295:S 2291:m 2288:p 2283:) 2281:m 2279:( 2277:p 2268:S 2262:m 2255:λ 2253:| 2248:λ 2240:| 2238:1 2235:z 2231:0 2228:z 2226:| 2221:1 2218:z 2215:0 2212:z 2210:2 2205:p 2199:λ 2193:λ 2188:2 2183:λ 2178:3 2172:λ 2170:| 2165:λ 2160:) 2158:1 2155:z 2151:λ 2147:0 2144:z 2140:λ 2138:( 2134:) 2132:1 2129:w 2125:0 2122:w 2120:( 2116:) 2114:1 2111:w 2107:0 2104:w 2102:( 2100:p 2096:1 2093:z 2089:0 2086:z 2084:( 2082:p 2064:1 2061:= 2056:2 2051:) 2045:2 2040:| 2035:1 2031:z 2027:| 2022:+ 2017:2 2012:| 2007:0 2003:z 1999:| 1993:( 1988:= 1983:4 1978:| 1973:1 1969:z 1965:| 1960:+ 1955:2 1950:| 1945:1 1941:z 1937:| 1930:2 1925:| 1920:0 1916:z 1912:| 1907:2 1899:4 1894:| 1889:0 1885:z 1881:| 1876:+ 1871:2 1866:| 1861:1 1857:z 1853:| 1846:2 1841:| 1836:0 1832:z 1828:| 1823:4 1820:= 1815:2 1810:) 1804:2 1799:| 1794:1 1790:z 1786:| 1776:2 1771:| 1766:0 1762:z 1758:| 1752:( 1747:+ 1742:1 1738:z 1727:0 1723:z 1719:2 1706:1 1702:z 1696:0 1692:z 1688:2 1675:p 1669:R 1665:C 1660:2 1656:) 1654:1 1651:z 1647:0 1644:z 1642:( 1640:p 1633:1 1630:z 1626:0 1623:z 1621:| 1617:3 1600:. 1597:) 1592:2 1587:| 1582:1 1578:z 1574:| 1564:2 1559:| 1554:0 1550:z 1546:| 1541:, 1531:1 1527:z 1521:0 1517:z 1513:2 1510:( 1507:= 1504:) 1499:1 1495:z 1491:, 1486:0 1482:z 1478:( 1475:p 1461:p 1451:y 1447:x 1443:z 1439:z 1435:z 1431:y 1427:x 1423:z 1416:x 1412:z 1410:| 1405:R 1403:× 1401:C 1396:) 1394:x 1390:z 1388:( 1383:S 1376:1 1373:z 1369:0 1366:z 1364:| 1359:C 1354:) 1352:1 1349:z 1345:0 1342:z 1340:( 1331:S 1324:. 1312:) 1307:3 1303:x 1299:, 1294:2 1290:x 1286:i 1283:+ 1278:1 1274:x 1270:( 1267:= 1264:) 1261:x 1258:, 1255:z 1252:( 1246:) 1241:3 1237:x 1233:, 1228:2 1224:x 1220:, 1215:1 1211:x 1207:( 1181:) 1176:4 1172:x 1168:i 1165:+ 1160:3 1156:x 1152:, 1147:2 1143:x 1139:i 1136:+ 1131:1 1127:x 1123:( 1120:= 1117:) 1112:1 1108:z 1104:, 1099:0 1095:z 1091:( 1085:) 1080:4 1076:x 1072:, 1067:3 1063:x 1059:, 1054:2 1050:x 1046:, 1041:1 1037:x 1033:( 1015:C 1009:R 1005:C 999:R 993:C 987:R 974:2 970:3 965:S 961:S 957:p 949:4 946:x 942:3 939:x 935:2 932:x 928:1 925:x 921:R 917:4 914:x 910:3 907:x 903:2 900:x 896:1 893:x 889:3 883:n 879:x 875:2 872:x 868:1 865:x 849:1 846:+ 843:n 838:R 816:) 811:1 808:+ 805:n 801:x 797:, 791:, 786:2 782:x 778:, 773:1 769:x 765:( 743:n 739:S 728:n 702:) 699:1 696:+ 693:n 690:( 676:n 672:n 640:. 635:8 631:S 618:S 609:7 605:S 583:, 578:4 574:S 565:7 561:S 552:3 548:S 526:, 521:2 517:S 508:3 504:S 495:1 491:S 469:, 464:1 460:S 451:1 447:S 438:0 434:S 398:C 374:R 369:2 348:R 321:S 315:S 305:S 288:2 283:S 277:S 271:S 267:S 263:p 258:3 253:S 243:S 225:, 220:2 216:S 208:p 194:3 190:S 181:1 177:S 160:2 156:3 148:3 140:2 132:2 128:3 59:S 53:R 47:R 41:S 20:)

Index

Hopf bundle

stereographic projection

keyrings
differential topology
3-sphere
hypersphere
four-dimensional space
circles
sphere
Heinz Hopf
fiber bundle
continuous function
great circle
Hopf 1931
embedded
locally
product space
homotopy groups of spheres
principal bundle
circle group
Stereographic projection
tori
Villarceau circles
circle
inverse image
Topology and geometry
homeomorphic
circles

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