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3-sphere

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36: 1986:. The boundary of a 3-ball is a 2-sphere, and these two 2-spheres are to be identified. That is, imagine a pair of 3-balls of the same size, then superpose them so that their 2-spherical boundaries match, and let matching pairs of points on the pair of 2-spheres be identically equivalent to each other. In analogy with the case of the 2-sphere (see below), the gluing surface is called an equatorial sphere. 3628: 3075: 120: 2368: 3512: 5724: 1989:
Note that the interiors of the 3-balls are not glued to each other. One way to think of the fourth dimension is as a continuous real-valued function of the 3-dimensional coordinates of the 3-ball, perhaps considered to be "temperature". We take the "temperature" to be zero along the gluing 2-sphere
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is a 2-sphere (unless the hyperplane is tangent to the 3-sphere, in which case the intersection is a single point). As a 3-sphere moves through a given three-dimensional hyperplane, the intersection starts out as a point, then becomes a growing 2-sphere that reaches its maximal size when the
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This construction is analogous to a construction of a 2-sphere, performed by gluing the boundaries of a pair of disks. A disk is a 2-ball, and the boundary of a disk is a circle (a 1-sphere). Let a pair of disks be of the same diameter. Superpose them and glue corresponding points on their
5459: 4826: 4397: 4147: 2041:. Returning to our picture of the unit two-sphere sitting on the Euclidean plane: Consider a geodesic in the plane, based at the origin, and map this to a geodesic in the two-sphere of the same length, based at the south pole. Under this map all points of the circle of radius 6252:
A Warning on terminology: Our two-sphere is defined in three-dimensional space, where it is the boundary of a three-dimensional ball. This terminology is standard among mathematicians, but not among physicists. So don't be surprised if you find people calling the two-sphere a
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and let one of the 3-balls be "hot" and let the other 3-ball be "cold". The "hot" 3-ball could be thought of as the "upper hemisphere" and the "cold" 3-ball could be thought of as the "lower hemisphere". The temperature is highest/lowest at the centers of the two 3-balls.
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After removing a single point from the 2-sphere, what remains is homeomorphic to the Euclidean plane. In the same way, removing a single point from the 3-sphere yields three-dimensional space. An extremely useful way to see this is via
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In a given three-dimensional hyperplane, a 3-sphere can rotate about an "equatorial plane" (analogous to a 2-sphere rotating about a central axis), in which case it appears to be a 2-sphere whose size is constant.
4243: 3988: 5824: 5070: 985: 3030: 2782: 2363:{\displaystyle {\begin{aligned}x_{0}&=r\cos \psi \\x_{1}&=r\sin \psi \cos \theta \\x_{2}&=r\sin \psi \sin \theta \cos \varphi \\x_{3}&=r\sin \psi \sin \theta \sin \varphi \end{aligned}}} 277: 539: 3993: 3314: 3176: 2180: 3171: 3507:{\displaystyle {\begin{aligned}x_{0}&=\cos \xi _{1}\sin \eta \\x_{1}&=\sin \xi _{1}\sin \eta \\x_{2}&=\cos \xi _{2}\cos \eta \\x_{3}&=\sin \xi _{2}\cos \eta .\end{aligned}}} 1156: 1994:
boundaries. Again one may think of the third dimension as temperature. Likewise, we may inflate the 2-sphere, moving the pair of disks to become the northern and southern hemispheres.
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It is called a 3-sphere because topologically, the surface itself is 3-dimensional, even though it is curved into the 4th dimension. This means that a 3-sphere is an example of a
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with a pure quaternion. (Note that the numerator and denominator commute here even though quaternionic multiplication is generally noncommutative). The inverse of this map takes
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with the plane. Stereographic projection of a 3-sphere (again removing the north pole) maps to three-space in the same manner. (Notice that, since stereographic projection is
2591: 2606: 2432: 762: 2823: 3764: 1194:. What this means, in the broad sense, is that any loop, or circular path, on the 3-sphere can be continuously shrunk to a point without leaving the 3-sphere. The 5719:{\displaystyle {\begin{pmatrix}e^{i\,\xi _{1}}\sin \eta &e^{i\,\xi _{2}}\cos \eta \\-e^{-i\,\xi _{2}}\cos \eta &e^{-i\,\xi _{1}}\sin \eta \end{pmatrix}}.} 1758:). One can even find three linearly independent and nonvanishing vector fields. These may be taken to be any left-invariant vector fields forming a basis for the 1166:
hyperplane cuts right through the "equator" of the 3-sphere. Then the 2-sphere shrinks again down to a single point as the 3-sphere leaves the hyperplane.
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There are several well-known constructions of the three-sphere. Here we describe gluing a pair of three-balls and then the one-point compactification.
4875: 4553: 3892: 5454:{\displaystyle x_{1}+x_{2}i+x_{3}j+x_{4}k\mapsto {\begin{pmatrix}\;\;\,x_{1}+ix_{2}&x_{3}+ix_{4}\\-x_{3}+ix_{4}&x_{1}-ix_{2}\end{pmatrix}}.} 5093:
inherits an important structure, namely that of quaternionic multiplication. Because the set of unit quaternions is closed under multiplication,
4821:{\displaystyle p=\left({\frac {-1+\|v\|^{2}}{1+\|v\|^{2}}},{\frac {2\mathbf {v} }{1+\|v\|^{2}}}\right)={\frac {-1+\mathbf {v} }{1+\mathbf {v} }}} 4392:{\displaystyle p=\left({\frac {1-\|u\|^{2}}{1+\|u\|^{2}}},{\frac {2\mathbf {u} }{1+\|u\|^{2}}}\right)={\frac {1+\mathbf {u} }{1-\mathbf {u} }}} 4142:{\displaystyle {\begin{aligned}z_{1}&=e^{i\,(\xi _{1}+\xi _{2})}\sin \eta \\z_{2}&=e^{i\,(\xi _{2}-\xi _{1})}\cos \eta .\end{aligned}}} 6194: 6160: 6082: 6042: 2038: 5746: 2045:
are sent to the north pole. Since the open unit disk is homeomorphic to the Euclidean plane, this is again a one-point compactification.
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The set of unit quaternions is then given by matrices of the above form with unit determinant. This matrix subgroup is precisely the
5020: 918: 79: 103:, the curves intersect each other orthogonally (in the yellow points) as in 4D. All curves are circles: the curves that intersect 3052: 2938: 2724: 6227: 513:{\displaystyle \sum _{i=0}^{3}(x_{i}-C_{i})^{2}=(x_{0}-C_{0})^{2}+(x_{1}-C_{1})^{2}+(x_{2}-C_{2})^{2}+(x_{3}-C_{3})^{2}=r^{2}.} 5908:, Stephen L. Lipscomb develops the concept of the hypersphere dimensions as it relates to art, architecture, and mathematics. 6002: 720:{\displaystyle S^{3}=\left\{(x_{0},x_{1},x_{2},x_{3})\in \mathbb {R} ^{4}:x_{0}^{2}+x_{1}^{2}+x_{2}^{2}+x_{3}^{2}=1\right\}.} 2048:
The exponential map for 3-sphere is similarly constructed; it may also be discussed using the fact that the 3-sphere is the
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Zamboj, Michal (8 Jan 2021). "Synthetic construction of the Hopf fibration in a double orthogonal projection of 4-space".
6241: 6030: 3287:{\displaystyle {\begin{aligned}z_{1}&=e^{i\,\xi _{1}}\sin \eta \\z_{2}&=e^{i\,\xi _{2}}\cos \eta .\end{aligned}}} 6107: 2117:
it is impossible to find a single set of coordinates that cover the entire space. Just as on the 2-sphere, one must use
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which consists of the real numbers 1 and −1 is also a Lie group, albeit a 0-dimensional one). One might think that
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while the 4-dimensional hypervolume (the content of the 4-dimensional region, or ball, bounded by the 3-sphere) is
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of the hypersphere's parallels (red), meridians (blue) and hypermeridians (green). Because this projection is
61: 4205: 3079: 2031: 2004: 1921:{\displaystyle (z_{1},z_{2})\cdot \lambda =(z_{1}\lambda ,z_{2}\lambda )\quad \forall \lambda \in \mathbb {T} } 1775: 96: 1018:
for details of this development of the three-sphere. This view of the 3-sphere is the basis for the study of
1801: 1763: 1751: 1195: 262: 2696:{\displaystyle dV=r^{3}\left(\sin ^{2}\psi \,\sin \theta \right)\,d\psi \wedge d\theta \wedge d\varphi .} 1049: 5501: 2144: 2455: 1014:, so the 3-sphere is important in the polar view of 4-space involved in quaternion multiplication. See 5887:, Mark A. Peterson describes three different ways of visualizing 3-spheres and points out language in 6358: 6119: 5733:
as a exponential of a linear combination of the Pauli matrices. It is seen that an arbitrary element
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Much of the interesting geometry of the 3-sphere stems from the fact that the 3-sphere has a natural
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above form simple orthogonal grids on the tori. See image to right. In the degenerate cases, when
166:, it is the set of points equidistant from a fixed central point. The interior of a 3-sphere is a 6268: 6223: 2408: 1983: 6059: 2803: 902:{\displaystyle S^{3}=\left\{(z_{1},z_{2})\in \mathbb {C} ^{2}:|z_{1}|^{2}+|z_{2}|^{2}=1\right\}} 2914:{\displaystyle \tau =(\cos \theta )i+(\sin \theta \cos \varphi )j+(\sin \theta \sin \varphi )k} 2103:
by three coordinates, just as one can parameterize the 2-sphere using two coordinates (such as
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in the 3-sphere gives a homology sphere; typically these are not homeomorphic to the 3-sphere.
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Another way to state this result is if we express the matrix representation of an element of
3876:{\displaystyle ds^{2}=d\eta ^{2}+\sin ^{2}\eta \,d\xi _{1}^{2}+\cos ^{2}\eta \,d\xi _{2}^{2}} 6363: 6278: 6127: 5133: 5118: 5005: 4995: 2122: 1683: 1199: 1191: 6020: 5894: 5104: 5084: 5014:. Note that the transition function between these two charts on their overlap is given by 1669: 1342: 1293: 1267: 1183: 737: 163: 6123: 5970: 5965: 5955: 5946: 5478: 5240: 5161: 3979: 1767: 1755: 1739:). The only other spheres with such a structure are the 0-sphere and the 1-sphere (see 1231: 127:
into 3D space and covered with surface grid, showing structure as stack of 3D spheres (
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have infinite radius (= straight line). In this picture, the whole 3D space maps the
100: 6233: 6135: 1786: 1747: 1740: 1311: 6245: 1770:. For a general discussion of the number of linear independent vector fields on a 6317:: This article uses the alternate naming scheme for spheres in which a sphere in 6302: 6184: 6024: 5951: 5917: 5490: 5486: 5187: 5154: 5149: 4964:{\displaystyle \mathbf {v} ={\frac {1}{1-x_{0}}}\left(x_{1},x_{2},x_{3}\right).} 4642:{\displaystyle \mathbf {u} ={\frac {1}{1+x_{0}}}\left(x_{1},x_{2},x_{3}\right).} 3968:{\displaystyle dV=\sin \eta \cos \eta \,d\eta \wedge d\xi _{1}\wedge d\xi _{2}.} 3562: 2597: 1933: 1805: 1759: 1335: 1007: 190: 136: 92: 2037:
A somewhat different way to think of the one-point compactification is via the
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The Shape of Space: How to Visualize Surfaces and Three-dimensional Manifolds
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to the set of 2 × 2 complex matrices. It has the property that the
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of the hypersphere, whereas in the next picture the 3D space contained the
5186:, would form a Lie group, but this fails since octonion multiplication is 1310:. Infinitely many homology spheres are now known to exist. For example, a 5925: 5856: 5183: 3561:. These coordinates are useful in the description of the 3-sphere as the 2134: 2104: 1975: 1187: 156: 119: 5941: 1735:
structure given by quaternion multiplication (see the section below on
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Experiencing Geometry: In Euclidean, Spherical, and Hyperbolic Spaces
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equates to a round trip of the torus in the 2 respective directions.
3752: 2806:. Now the unit imaginary quaternions all lie on the unit 2-sphere in 2715: 1388:
but otherwise follow no discernible pattern. For more discussion see
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Every non-empty intersection of a 3-sphere with a three-dimensional
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The round metric on the 3-sphere in these coordinates is given by
3708: 3626: 3073: 118: 91: 5202:. It turns out that the only spheres that are parallelizable are 2097:. As a 3-dimensional manifold one should be able to parameterize 1292:. Any topological space with these homology groups is known as a 4174:
specifies the position along each circle. One round trip (0 to 2
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The 3-sphere centered at the origin with radius 1 is called the
5065:{\displaystyle \mathbf {v} ={\frac {1}{\|u\|^{2}}}\mathbf {u} } 3649:) direction, represented by the blue arrow, although the terms 980:{\displaystyle S^{3}=\left\{q\in \mathbb {H} :\|q\|=1\right\}.} 3110:
For unit radius another choice of hyperspherical coordinates,
29: 3640:) direction, represented by the red arrow, and the toroidal ( 1300:
conjectured that all homology 3-spheres are homeomorphic to
3025:{\displaystyle q=e^{\tau \psi }=x_{0}+x_{1}i+x_{2}j+x_{3}k} 2777:{\displaystyle q=e^{\tau \psi }=\cos \psi +\tau \sin \psi } 2066:
are redundant since they are subject to the condition that
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Another convenient set of coordinates can be obtained via
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These coordinates have an elegant description in terms of
1700:. As with all spheres, the 3-sphere has constant positive 6226:(2001). "Chapter 20: 3-spheres and hyperbolic 3-spaces". 5125:
Lie group of dimension 3. When thought of as a Lie group
2125:. Some different choices of coordinates are given below. 2034:, round spheres are sent to round spheres or to planes.) 1039:
The 3-dimensional surface volume of a 3-sphere of radius
1766:. It follows that the tangent bundle of the 3-sphere is 5565: 5319: 1746:
Unlike the 2-sphere, the 3-sphere admits nonvanishing
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We could just as well have projected from the point
3982:, make a simple substitution in the equations above 5170:, the set of unit quaternions (The degenerate case 4466:. In the second equality above, we have identified 3106:
and their corresponding fibers with the same color.
2153:. One such choice — by no means unique — is to use 2007:. We first describe the lower-dimensional version. 1762:of the 3-sphere. This implies that the 3-sphere is 5818: 5718: 5453: 5064: 4963: 4820: 4641: 4391: 4141: 3967: 3875: 3616: 3506: 3286: 3024: 2913: 2776: 2695: 2585: 2426: 2362: 1920: 1150: 1088: 979: 901: 719: 512: 5103:. Moreover, since quaternionic multiplication is 2449:on the 3-sphere in these coordinates is given by 1936:of this action is homeomorphic to the two-sphere 1223:that is homeomorphic to the 3-sphere is called a 6232:(second ed.). Prentice-Hall. Archived from 1377:is infinite cyclic. The higher-homotopy groups ( 6261:Journal of Computational Design and Engineering 4214:from a pole onto the corresponding equatorial 2010:Rest the south pole of a unit 2-sphere on the 1151:{\displaystyle H={\frac {1}{2}}\pi ^{2}r^{4}.} 6186:Art meets mathematics in the fourth dimension 5906:Art Meets Mathematics in the Fourth Dimension 3078:The Hopf fibration can be visualized using a 1696:on the 3-sphere giving it the structure of a 8: 5993:(1948). "Quaternions et espace elliptique". 5045: 5038: 4765: 4758: 4724: 4717: 4700: 4693: 4339: 4332: 4298: 4291: 4274: 4267: 4223:. For example, if we project from the point 960: 954: 3051:is used to describe spatial rotations (cf. 5323: 5322: 5008:or "patches", which together cover all of 3617:{\displaystyle S^{1}\to S^{3}\to S^{2}.\,} 6272: 6155:. Cambridge: Cambridge University Press. 5802: 5792: 5782: 5771: 5748: 5688: 5683: 5676: 5653: 5648: 5641: 5613: 5608: 5604: 5581: 5576: 5572: 5560: 5558: 5434: 5418: 5406: 5390: 5373: 5357: 5345: 5329: 5324: 5314: 5302: 5286: 5270: 5257: 5251: 5233:, one obtains a matrix representation of 5057: 5048: 5032: 5024: 5022: 4947: 4934: 4921: 4903: 4887: 4879: 4877: 4810: 4797: 4785: 4768: 4745: 4739: 4727: 4703: 4681: 4668: 4625: 4612: 4599: 4581: 4565: 4557: 4555: 4381: 4368: 4359: 4342: 4319: 4313: 4301: 4277: 4258: 4245: 4112: 4099: 4091: 4087: 4070: 4042: 4029: 4021: 4017: 4000: 3992: 3990: 3956: 3940: 3923: 3894: 3867: 3862: 3854: 3842: 3829: 3824: 3816: 3804: 3791: 3775: 3766: 3613: 3604: 3591: 3578: 3572: 3482: 3459: 3436: 3413: 3390: 3367: 3344: 3321: 3313: 3311: 3260: 3255: 3251: 3234: 3209: 3204: 3200: 3183: 3175: 3173: 3013: 2997: 2981: 2968: 2952: 2940: 2825: 2738: 2726: 2665: 2650: 2638: 2623: 2608: 2567: 2559: 2547: 2534: 2510: 2497: 2479: 2466: 2457: 2410: 2313: 2262: 2220: 2187: 2179: 2177: 1914: 1913: 1891: 1875: 1850: 1837: 1828: 1139: 1129: 1115: 1107: 1085: 1079: 1069: 1051: 947: 946: 926: 920: 882: 877: 870: 861: 852: 847: 840: 831: 822: 818: 817: 804: 791: 770: 764: 697: 692: 679: 674: 661: 656: 643: 638: 625: 621: 620: 607: 594: 581: 568: 547: 541: 501: 488: 478: 465: 449: 439: 426: 410: 400: 387: 371: 361: 348: 332: 322: 309: 296: 285: 279: 80:Learn how and when to remove this message 5239:. One convenient choice is given by the 2434:, except for the degenerate cases, when 1394: 43:This article includes a list of general 6244:(1985). "Chapter 14: The Hypersphere". 5982: 4980:coordinates are defined everywhere but 3978:To get the interlocking circles of the 3100:to a ball. This image shows points on 2802:. This is the quaternionic analogue of 2795:; that is, a quaternion that satisfies 2442:, in which case they describe a point. 2014:-plane in three-space. We map a point 1800:giving the 3-sphere the structure of a 6033:. Vol. 2 (7th ed.). Moscow: 5842:are constrained to lie on a 3-sphere. 5829:The condition that the determinant of 2133:It is convenient to have some sort of 756:). The unit 3-sphere is then given by 5897:viewed the Universe in the same way; 5874:, and a 4-sphere is referred to as a 5190:. The octonionic structure does give 5152:that admit a Lie group structure are 2111:). Due to the nontrivial topology of 998:one identifies the 3-sphere with the 7: 6060:"The Flat Torus in the Three-Sphere" 5870:, the 3-sphere is referred to as an 5833:is +1 implies that the coefficients 2393:. Note that, for any fixed value of 2018:of the sphere (minus the north pole 1736: 1209:The 3-sphere is homeomorphic to the 6149:Rovelli, Carlo (9 September 2021). 5227:representation of the quaternions, 3557:can take any values between 0 and 2 2060:The four Euclidean coordinates for 1089:{\displaystyle SV=2\pi ^{2}r^{3}\,} 1016:polar decomposition of a quaternion 6152:General Relativity: The Essentials 3631:A diagram depicting the poloidal ( 2928:in this form, the unit quaternion 2405:parameterize a 2-sphere of radius 2056:Coordinate systems on the 3-sphere 1904: 49:it lacks sufficient corresponding 25: 5546:we can then write any element of 3055:), it describes a rotation about 3053:quaternions and spatial rotations 2586:{\displaystyle ds^{2}=r^{2}\left} 1958:, the Hopf bundle is nontrivial. 730:It is often convenient to regard 151:is a 4-dimensional analogue of a 6321:-dimensional space is termed an 6189:(2 ed.). Berlin: Springer. 5160:, thought of as the set of unit 5058: 5025: 4880: 4865:. The inverse of this map takes 4811: 4798: 4746: 4558: 4382: 4369: 4320: 3297:This could also be expressed in 3132:, makes use of the embedding of 2026:to the intersection of the line 1234:of the 3-sphere are as follows: 34: 5866:, a 1965 sequel to Flatland by 3751:, these coordinates describe a 1903: 6073:Schwichtenberg, Jakob (2015). 6003:Pontifical Academy of Sciences 5311: 5083:When considered as the set of 4118: 4092: 4048: 4022: 3597: 3584: 2905: 2884: 2875: 2854: 2845: 2833: 1982:the boundaries of a pair of 3- 1974:A 3-sphere can be constructed 1900: 1868: 1856: 1830: 878: 862: 848: 832: 810: 784: 613: 561: 485: 458: 446: 419: 407: 380: 368: 341: 329: 302: 1: 6031:Course of Theoretical Physics 3707:parameterize a 2-dimensional 1190:without boundary. It is also 5860:, published in 1884, and in 5099:takes on the structure of a 1668:The 3-sphere is naturally a 6112:American Journal of Physics 5884:American Journal of Physics 5524:Using our Hopf coordinates 5148:It turns out that the only 4990:coordinates everywhere but 4470:with a unit quaternion and 2427:{\displaystyle r\sin \psi } 155:, and is the 3-dimensional 6380: 6183:Lipscomb, Stephen (2014). 6106:Peterson, Mark A. (1979). 6026:Classical Theory of Fields 5113:can be regarded as a real 4656:, in which case the point 4165:specify which circle, and 2135:hyperspherical coordinates 2129:Hyperspherical coordinates 2022:) to the plane by sending 1998:One-point compactification 1390:homotopy groups of spheres 1211:one-point compactification 6339:Four-dimensional geometry 4200:Stereographic coordinates 3521:runs over the range 0 to 3144:. In complex coordinates 2793:unit imaginary quaternion 1820:, the action is given by 1774:-sphere, see the article 1206:) with these properties. 229:is the set of all points 193:, a 3-sphere with center 6108:"Dante and the 3-sphere" 5901:supports the same idea. 5196:one important property: 4206:stereographic projection 3080:stereographic projection 2381:run over the range 0 to 2143:in analogy to the usual 2005:stereographic projection 1962:Topological construction 1781:There is an interesting 1776:vector fields on spheres 1308:Poincaré homology sphere 1010:is important for planar 990:This description as the 115:of the bulk hypersphere. 97:Stereographic projection 5493:of the matrix image of 3886:and the volume form by 3667:For any fixed value of 1948:is not homeomorphic to 1802:principal circle bundle 527:and is usually denoted 105:⟨0,0,0,1⟩ 64:more precise citations. 5820: 5787: 5720: 5455: 5066: 4965: 4822: 4643: 4393: 4143: 3969: 3877: 3664: 3657:are arbitrary in this 3618: 3508: 3288: 3107: 3026: 2915: 2778: 2710:. Any unit quaternion 2697: 2587: 2428: 2364: 1922: 1288:for all other indices 1174:Topological properties 1152: 1090: 981: 903: 721: 514: 301: 132: 116: 6075:Physics from symmetry 5821: 5767: 5721: 5502:special unitary group 5456: 5067: 4966: 4859:is another vector in 4823: 4644: 4394: 4227:we can write a point 4144: 3970: 3878: 3630: 3619: 3509: 3289: 3094:and then compressing 3077: 3027: 2916: 2779: 2698: 2588: 2429: 2365: 2145:spherical coordinates 2052:of unit quaternions. 1923: 1153: 1091: 1035:Elementary properties 982: 904: 722: 515: 281: 123:Direct projection of 122: 95: 6283:10.1093/jcde/qwab018 6138:on 23 February 2013. 5747: 5557: 5469:algebra homomorphism 5250: 5021: 4876: 4667: 4554: 4244: 3989: 3893: 3765: 3711:. Rings of constant 3571: 3310: 3172: 3059:through an angle of 2939: 2824: 2725: 2714:can be written as a 2607: 2456: 2409: 2176: 1827: 1674:embedded submanifold 1672:, in fact, a closed 1664:Geometric properties 1225:topological 3-sphere 1198:, proved in 2003 by 1106: 1050: 919: 763: 736:as the space with 2 540: 278: 6224:Henderson, David W. 6124:1979AmJPh..47.1031P 6021:Lifshitz, Evgeny M. 5852:Edwin Abbott Abbott 3872: 3834: 1808:. If one thinks of 1702:sectional curvature 1698:Riemannian manifold 1402: 1396:Homotopy groups of 1196:Poincaré conjecture 702: 684: 666: 648: 263:4-dimensional space 162:. In 4-dimensional 27:Mathematical object 6349:Geometric topology 6344:Algebraic topology 6300:Weisstein, Eric W. 6077:. Cham: Springer. 6058:Banchoff, Thomas. 5816: 5740:can be written as 5716: 5707: 5513:as a Lie group is 5464:This map gives an 5451: 5442: 5182:, the set of unit 5062: 5004:consisting of two 4994:. This defines an 4961: 4818: 4639: 4389: 4139: 4137: 3965: 3873: 3858: 3820: 3689:, the coordinates 3665: 3614: 3504: 3502: 3284: 3282: 3108: 3022: 2911: 2774: 2693: 2583: 2424: 2360: 2358: 1918: 1395: 1219:. In general, any 1148: 1086: 1002:in the quaternion 977: 899: 738:complex dimensions 717: 688: 670: 652: 634: 510: 133: 117: 6354:Analytic geometry 6242:Weeks, Jeffrey R. 6196:978-3-319-06254-9 6162:978-1-00-901369-7 6118:(12): 1031–1035. 6084:978-3-319-19201-7 6044:978-5-02-014420-0 5991:Lemaître, Georges 5890:The Divine Comedy 5199:parallelizability 5131:is often denoted 5055: 5006:coordinate charts 4910: 4816: 4775: 4734: 4588: 4387: 4349: 4308: 2123:coordinate charts 1980:"gluing" together 1661: 1660: 1294:homology 3-sphere 1221:topological space 1123: 1012:polar coordinates 90: 89: 82: 16:(Redirected from 6371: 6324: 6320: 6313: 6312: 6286: 6276: 6255: 6237: 6209: 6208: 6180: 6174: 6173: 6171: 6169: 6146: 6140: 6139: 6134:. Archived from 6103: 6097: 6096: 6070: 6064: 6063: 6055: 6049: 6048: 6013: 6007: 6006: 5987: 5841: 5832: 5825: 5823: 5822: 5817: 5812: 5808: 5807: 5806: 5797: 5796: 5786: 5781: 5739: 5732: 5725: 5723: 5722: 5717: 5712: 5711: 5695: 5694: 5693: 5692: 5660: 5659: 5658: 5657: 5620: 5619: 5618: 5617: 5588: 5587: 5586: 5585: 5549: 5545: 5520: 5512: 5506: 5496: 5485:is equal to the 5484: 5481:of a quaternion 5476: 5460: 5458: 5457: 5452: 5447: 5446: 5439: 5438: 5423: 5422: 5411: 5410: 5395: 5394: 5378: 5377: 5362: 5361: 5350: 5349: 5334: 5333: 5307: 5306: 5291: 5290: 5275: 5274: 5262: 5261: 5238: 5232: 5219: 5213: 5207: 5195: 5181: 5175: 5169: 5159: 5144: 5136: 5130: 5112: 5098: 5092: 5085:unit quaternions 5075:and vice versa. 5071: 5069: 5068: 5063: 5061: 5056: 5054: 5053: 5052: 5033: 5028: 5013: 5003: 4993: 4989: 4983: 4979: 4970: 4968: 4967: 4962: 4957: 4953: 4952: 4951: 4939: 4938: 4926: 4925: 4911: 4909: 4908: 4907: 4888: 4883: 4868: 4864: 4858: 4827: 4825: 4824: 4819: 4817: 4815: 4814: 4802: 4801: 4786: 4781: 4777: 4776: 4774: 4773: 4772: 4750: 4749: 4740: 4735: 4733: 4732: 4731: 4709: 4708: 4707: 4682: 4659: 4655: 4648: 4646: 4645: 4640: 4635: 4631: 4630: 4629: 4617: 4616: 4604: 4603: 4589: 4587: 4586: 4585: 4566: 4561: 4546: 4540: 4505: 4469: 4465: 4443: 4435: 4429: 4398: 4396: 4395: 4390: 4388: 4386: 4385: 4373: 4372: 4360: 4355: 4351: 4350: 4348: 4347: 4346: 4324: 4323: 4314: 4309: 4307: 4306: 4305: 4283: 4282: 4281: 4259: 4236: 4230: 4226: 4219: 4213: 4195: 4186: 4177: 4173: 4164: 4155: 4148: 4146: 4145: 4140: 4138: 4122: 4121: 4117: 4116: 4104: 4103: 4075: 4074: 4052: 4051: 4047: 4046: 4034: 4033: 4005: 4004: 3974: 3972: 3971: 3966: 3961: 3960: 3945: 3944: 3882: 3880: 3879: 3874: 3871: 3866: 3847: 3846: 3833: 3828: 3809: 3808: 3796: 3795: 3780: 3779: 3750: 3748: 3747: 3744: 3741: 3740: 3732: 3728: 3719: 3706: 3688: 3686: 3685: 3682: 3679: 3678: 3670: 3648: 3639: 3623: 3621: 3620: 3615: 3609: 3608: 3596: 3595: 3583: 3582: 3560: 3556: 3547: 3538: 3536: 3535: 3532: 3529: 3528: 3520: 3513: 3511: 3510: 3505: 3503: 3487: 3486: 3464: 3463: 3441: 3440: 3418: 3417: 3395: 3394: 3372: 3371: 3349: 3348: 3326: 3325: 3302: 3293: 3291: 3290: 3285: 3283: 3267: 3266: 3265: 3264: 3239: 3238: 3216: 3215: 3214: 3213: 3188: 3187: 3164: 3143: 3137: 3131: 3105: 3099: 3093: 3087: 3070:Hopf coordinates 3065: 3058: 3050: 3043: 3031: 3029: 3028: 3023: 3018: 3017: 3002: 3001: 2986: 2985: 2973: 2972: 2960: 2959: 2931: 2927: 2920: 2918: 2917: 2912: 2817:can be written: 2816: 2812: 2801: 2790: 2783: 2781: 2780: 2775: 2746: 2745: 2713: 2702: 2700: 2699: 2694: 2664: 2660: 2643: 2642: 2628: 2627: 2592: 2590: 2589: 2584: 2582: 2578: 2577: 2573: 2572: 2571: 2552: 2551: 2539: 2538: 2515: 2514: 2502: 2501: 2484: 2483: 2471: 2470: 2441: 2437: 2433: 2431: 2430: 2425: 2404: 2400: 2396: 2392: 2389:runs over 0 to 2 2388: 2384: 2380: 2376: 2369: 2367: 2366: 2361: 2359: 2318: 2317: 2267: 2266: 2225: 2224: 2192: 2191: 2168: 2152: 2142: 2116: 2102: 2096: 2065: 2044: 2029: 2025: 2021: 2017: 2013: 1957: 1947: 1941: 1927: 1925: 1924: 1919: 1917: 1896: 1895: 1880: 1879: 1855: 1854: 1842: 1841: 1819: 1813: 1799: 1793: 1773: 1727: 1723: 1722: 1720: 1719: 1714: 1711: 1691: 1684:Euclidean metric 1681: 1657: 1647: 1630: 1606: 1589: 1572: 1562: 1552: 1542: 1532: 1522: 1512: 1502: 1492: 1476: 1408: 1403: 1401: 1383: 1376: 1364: 1333: 1332: 1330: 1329: 1324: 1321: 1305: 1291: 1287: 1265: 1249: 1218: 1200:Grigori Perelman 1192:simply connected 1186:, 3-dimensional 1178:A 3-sphere is a 1157: 1155: 1154: 1149: 1144: 1143: 1134: 1133: 1124: 1116: 1095: 1093: 1092: 1087: 1084: 1083: 1074: 1073: 1042: 1024:Georges Lemaître 1022:as developed by 986: 984: 983: 978: 973: 969: 950: 931: 930: 908: 906: 905: 900: 898: 894: 887: 886: 881: 875: 874: 865: 857: 856: 851: 845: 844: 835: 827: 826: 821: 809: 808: 796: 795: 775: 774: 755: 745: 735: 726: 724: 723: 718: 713: 709: 701: 696: 683: 678: 665: 660: 647: 642: 630: 629: 624: 612: 611: 599: 598: 586: 585: 573: 572: 552: 551: 532: 519: 517: 516: 511: 506: 505: 493: 492: 483: 482: 470: 469: 454: 453: 444: 443: 431: 430: 415: 414: 405: 404: 392: 391: 376: 375: 366: 365: 353: 352: 337: 336: 327: 326: 314: 313: 300: 295: 270: 260: 228: 224: 106: 85: 78: 74: 71: 65: 60:this article by 51:inline citations 38: 37: 30: 21: 6379: 6378: 6374: 6373: 6372: 6370: 6369: 6368: 6329: 6328: 6322: 6318: 6298: 6297: 6294: 6289: 6258: 6240: 6222: 6218: 6216:Further reading 6213: 6212: 6197: 6182: 6181: 6177: 6167: 6165: 6163: 6148: 6147: 6143: 6132:10.1119/1.11968 6105: 6104: 6100: 6085: 6072: 6071: 6067: 6057: 6056: 6052: 6045: 6037:. p. 385. 6015: 6014: 6010: 5989: 5988: 5984: 5979: 5961:Poincaré sphere 5914: 5881:Writing in the 5848: 5840: 5834: 5830: 5798: 5788: 5766: 5762: 5745: 5744: 5734: 5730: 5706: 5705: 5684: 5672: 5670: 5649: 5637: 5631: 5630: 5609: 5600: 5598: 5577: 5568: 5561: 5555: 5554: 5547: 5543: 5536: 5525: 5518: 5508: 5504: 5494: 5482: 5472: 5441: 5440: 5430: 5414: 5412: 5402: 5386: 5380: 5379: 5369: 5353: 5351: 5341: 5325: 5315: 5298: 5282: 5266: 5253: 5248: 5247: 5234: 5228: 5215: 5209: 5203: 5191: 5177: 5171: 5165: 5162:complex numbers 5153: 5138: 5132: 5126: 5108: 5094: 5088: 5081: 5079:Group structure 5044: 5037: 5019: 5018: 5009: 4999: 4991: 4985: 4981: 4975: 4943: 4930: 4917: 4916: 4912: 4899: 4892: 4874: 4873: 4866: 4860: 4856: 4849: 4842: 4832: 4803: 4787: 4764: 4751: 4741: 4723: 4710: 4699: 4683: 4680: 4676: 4665: 4664: 4657: 4653: 4621: 4608: 4595: 4594: 4590: 4577: 4570: 4552: 4551: 4542: 4538: 4531: 4524: 4517: 4507: 4501: 4491: 4481: 4471: 4467: 4464: 4457: 4450: 4439: 4437: 4431: 4430:is a vector in 4427: 4420: 4413: 4403: 4374: 4361: 4338: 4325: 4315: 4297: 4284: 4273: 4260: 4257: 4253: 4242: 4241: 4232: 4228: 4224: 4215: 4209: 4202: 4194: 4188: 4185: 4179: 4175: 4172: 4166: 4163: 4157: 4153: 4136: 4135: 4108: 4095: 4083: 4076: 4066: 4063: 4062: 4038: 4025: 4013: 4006: 3996: 3987: 3986: 3952: 3936: 3891: 3890: 3838: 3800: 3787: 3771: 3763: 3762: 3745: 3742: 3738: 3737: 3736: 3734: 3730: 3727: 3721: 3718: 3712: 3704: 3697: 3690: 3683: 3680: 3676: 3675: 3674: 3672: 3668: 3647: 3641: 3638: 3632: 3600: 3587: 3574: 3569: 3568: 3558: 3555: 3549: 3546: 3540: 3533: 3530: 3526: 3525: 3524: 3522: 3518: 3501: 3500: 3478: 3465: 3455: 3452: 3451: 3432: 3419: 3409: 3406: 3405: 3386: 3373: 3363: 3360: 3359: 3340: 3327: 3317: 3308: 3307: 3298: 3281: 3280: 3256: 3247: 3240: 3230: 3227: 3226: 3205: 3196: 3189: 3179: 3170: 3169: 3159: 3152: 3145: 3139: 3133: 3129: 3122: 3111: 3101: 3095: 3089: 3083: 3072: 3060: 3056: 3048: 3042: 3036: 3009: 2993: 2977: 2964: 2948: 2937: 2936: 2929: 2925: 2822: 2821: 2814: 2807: 2804:Euler's formula 2796: 2788: 2734: 2723: 2722: 2711: 2634: 2633: 2629: 2619: 2605: 2604: 2563: 2543: 2530: 2526: 2522: 2506: 2493: 2489: 2485: 2475: 2462: 2454: 2453: 2439: 2435: 2407: 2406: 2402: 2398: 2394: 2390: 2386: 2382: 2378: 2374: 2357: 2356: 2319: 2309: 2306: 2305: 2268: 2258: 2255: 2254: 2226: 2216: 2213: 2212: 2193: 2183: 2174: 2173: 2154: 2148: 2138: 2131: 2112: 2098: 2094: 2087: 2080: 2073: 2067: 2061: 2058: 2042: 2039:exponential map 2027: 2023: 2019: 2015: 2011: 2000: 1972: 1964: 1949: 1943: 1937: 1887: 1871: 1846: 1833: 1825: 1824: 1815: 1814:as a subset of 1809: 1795: 1789: 1771: 1737:group structure 1728:is the radius. 1725: 1715: 1712: 1709: 1708: 1706: 1705: 1687: 1677: 1670:smooth manifold 1666: 1656: 1650: 1646: 1639: 1633: 1629: 1622: 1615: 1609: 1605: 1598: 1592: 1588: 1581: 1575: 1571: 1565: 1561: 1555: 1551: 1545: 1541: 1535: 1531: 1525: 1521: 1515: 1511: 1505: 1501: 1495: 1488: 1470: 1464: 1406: 1397: 1378: 1370: 1366: 1358: 1350: 1346: 1343:homotopy groups 1325: 1322: 1319: 1318: 1316: 1315: 1301: 1289: 1277: 1271: 1268:infinite cyclic 1255: 1251: 1239: 1235: 1232:homology groups 1214: 1176: 1135: 1125: 1104: 1103: 1075: 1065: 1048: 1047: 1040: 1037: 1032: 939: 935: 922: 917: 916: 876: 866: 846: 836: 816: 800: 787: 783: 779: 766: 761: 760: 751: 741: 731: 619: 603: 590: 577: 564: 560: 556: 543: 538: 537: 528: 497: 484: 474: 461: 445: 435: 422: 406: 396: 383: 367: 357: 344: 328: 318: 305: 276: 275: 266: 258: 251: 244: 237: 230: 226: 222: 215: 208: 201: 194: 187: 164:Euclidean space 104: 86: 75: 69: 66: 56:Please help to 55: 39: 35: 28: 23: 22: 15: 12: 11: 5: 6377: 6375: 6367: 6366: 6361: 6356: 6351: 6346: 6341: 6331: 6330: 6327: 6326: 6293: 6292:External links 6290: 6288: 6287: 6267:(3): 836–854. 6256: 6238: 6236:on 2018-06-19. 6219: 6217: 6214: 6211: 6210: 6195: 6175: 6161: 6141: 6098: 6083: 6065: 6050: 6043: 6017:Landau, Lev D. 6008: 5981: 5980: 5978: 5975: 5974: 5973: 5971:Clifford torus 5968: 5966:Reeb foliation 5963: 5958: 5956:Riemann sphere 5949: 5947:Pauli matrices 5944: 5931: 5913: 5910: 5893:that suggests 5847: 5844: 5838: 5827: 5826: 5815: 5811: 5805: 5801: 5795: 5791: 5785: 5780: 5777: 5774: 5770: 5765: 5761: 5758: 5755: 5752: 5727: 5726: 5715: 5710: 5704: 5701: 5698: 5691: 5687: 5682: 5679: 5675: 5671: 5669: 5666: 5663: 5656: 5652: 5647: 5644: 5640: 5636: 5633: 5632: 5629: 5626: 5623: 5616: 5612: 5607: 5603: 5599: 5597: 5594: 5591: 5584: 5580: 5575: 5571: 5567: 5566: 5564: 5541: 5534: 5479:absolute value 5462: 5461: 5450: 5445: 5437: 5433: 5429: 5426: 5421: 5417: 5413: 5409: 5405: 5401: 5398: 5393: 5389: 5385: 5382: 5381: 5376: 5372: 5368: 5365: 5360: 5356: 5352: 5348: 5344: 5340: 5337: 5332: 5328: 5321: 5320: 5318: 5313: 5310: 5305: 5301: 5297: 5294: 5289: 5285: 5281: 5278: 5273: 5269: 5265: 5260: 5256: 5241:Pauli matrices 5188:nonassociative 5080: 5077: 5073: 5072: 5060: 5051: 5047: 5043: 5040: 5036: 5031: 5027: 4974:Note that the 4972: 4971: 4960: 4956: 4950: 4946: 4942: 4937: 4933: 4929: 4924: 4920: 4915: 4906: 4902: 4898: 4895: 4891: 4886: 4882: 4854: 4847: 4840: 4829: 4828: 4813: 4809: 4806: 4800: 4796: 4793: 4790: 4784: 4780: 4771: 4767: 4763: 4760: 4757: 4754: 4748: 4744: 4738: 4730: 4726: 4722: 4719: 4716: 4713: 4706: 4702: 4698: 4695: 4692: 4689: 4686: 4679: 4675: 4672: 4650: 4649: 4638: 4634: 4628: 4624: 4620: 4615: 4611: 4607: 4602: 4598: 4593: 4584: 4580: 4576: 4573: 4569: 4564: 4560: 4536: 4529: 4522: 4515: 4499: 4489: 4479: 4462: 4455: 4448: 4425: 4418: 4411: 4400: 4399: 4384: 4380: 4377: 4371: 4367: 4364: 4358: 4354: 4345: 4341: 4337: 4334: 4331: 4328: 4322: 4318: 4312: 4304: 4300: 4296: 4293: 4290: 4287: 4280: 4276: 4272: 4269: 4266: 4263: 4256: 4252: 4249: 4201: 4198: 4192: 4183: 4170: 4161: 4150: 4149: 4134: 4131: 4128: 4125: 4120: 4115: 4111: 4107: 4102: 4098: 4094: 4090: 4086: 4082: 4079: 4077: 4073: 4069: 4065: 4064: 4061: 4058: 4055: 4050: 4045: 4041: 4037: 4032: 4028: 4024: 4020: 4016: 4012: 4009: 4007: 4003: 3999: 3995: 3994: 3980:Hopf fibration 3976: 3975: 3964: 3959: 3955: 3951: 3948: 3943: 3939: 3935: 3932: 3929: 3926: 3922: 3919: 3916: 3913: 3910: 3907: 3904: 3901: 3898: 3884: 3883: 3870: 3865: 3861: 3857: 3853: 3850: 3845: 3841: 3837: 3832: 3827: 3823: 3819: 3815: 3812: 3807: 3803: 3799: 3794: 3790: 3786: 3783: 3778: 3774: 3770: 3725: 3716: 3702: 3695: 3671:between 0 and 3645: 3636: 3625: 3624: 3612: 3607: 3603: 3599: 3594: 3590: 3586: 3581: 3577: 3553: 3544: 3515: 3514: 3499: 3496: 3493: 3490: 3485: 3481: 3477: 3474: 3471: 3468: 3466: 3462: 3458: 3454: 3453: 3450: 3447: 3444: 3439: 3435: 3431: 3428: 3425: 3422: 3420: 3416: 3412: 3408: 3407: 3404: 3401: 3398: 3393: 3389: 3385: 3382: 3379: 3376: 3374: 3370: 3366: 3362: 3361: 3358: 3355: 3352: 3347: 3343: 3339: 3336: 3333: 3330: 3328: 3324: 3320: 3316: 3315: 3295: 3294: 3279: 3276: 3273: 3270: 3263: 3259: 3254: 3250: 3246: 3243: 3241: 3237: 3233: 3229: 3228: 3225: 3222: 3219: 3212: 3208: 3203: 3199: 3195: 3192: 3190: 3186: 3182: 3178: 3177: 3157: 3150: 3127: 3120: 3071: 3068: 3044:are as above. 3040: 3033: 3032: 3021: 3016: 3012: 3008: 3005: 3000: 2996: 2992: 2989: 2984: 2980: 2976: 2971: 2967: 2963: 2958: 2955: 2951: 2947: 2944: 2922: 2921: 2910: 2907: 2904: 2901: 2898: 2895: 2892: 2889: 2886: 2883: 2880: 2877: 2874: 2871: 2868: 2865: 2862: 2859: 2856: 2853: 2850: 2847: 2844: 2841: 2838: 2835: 2832: 2829: 2785: 2784: 2773: 2770: 2767: 2764: 2761: 2758: 2755: 2752: 2749: 2744: 2741: 2737: 2733: 2730: 2704: 2703: 2692: 2689: 2686: 2683: 2680: 2677: 2674: 2671: 2668: 2663: 2659: 2656: 2653: 2649: 2646: 2641: 2637: 2632: 2626: 2622: 2618: 2615: 2612: 2594: 2593: 2581: 2576: 2570: 2566: 2562: 2558: 2555: 2550: 2546: 2542: 2537: 2533: 2529: 2525: 2521: 2518: 2513: 2509: 2505: 2500: 2496: 2492: 2488: 2482: 2478: 2474: 2469: 2465: 2461: 2423: 2420: 2417: 2414: 2371: 2370: 2355: 2352: 2349: 2346: 2343: 2340: 2337: 2334: 2331: 2328: 2325: 2322: 2320: 2316: 2312: 2308: 2307: 2304: 2301: 2298: 2295: 2292: 2289: 2286: 2283: 2280: 2277: 2274: 2271: 2269: 2265: 2261: 2257: 2256: 2253: 2250: 2247: 2244: 2241: 2238: 2235: 2232: 2229: 2227: 2223: 2219: 2215: 2214: 2211: 2208: 2205: 2202: 2199: 2196: 2194: 2190: 2186: 2182: 2181: 2130: 2127: 2092: 2085: 2078: 2071: 2057: 2054: 1999: 1996: 1971: 1968: 1963: 1960: 1930: 1929: 1916: 1912: 1909: 1906: 1902: 1899: 1894: 1890: 1886: 1883: 1878: 1874: 1870: 1867: 1864: 1861: 1858: 1853: 1849: 1845: 1840: 1836: 1832: 1764:parallelizable 1756:tangent bundle 1665: 1662: 1659: 1658: 1654: 1648: 1644: 1637: 1631: 1627: 1620: 1613: 1607: 1603: 1596: 1590: 1586: 1579: 1573: 1569: 1563: 1559: 1553: 1549: 1543: 1539: 1533: 1529: 1523: 1519: 1513: 1509: 1503: 1499: 1493: 1486: 1483: 1480: 1477: 1466: 1461: 1460: 1457: 1454: 1451: 1448: 1445: 1442: 1439: 1436: 1433: 1430: 1427: 1424: 1421: 1418: 1415: 1412: 1409: 1386:finite abelian 1368: 1356: 1348: 1273: 1253: 1237: 1175: 1172: 1159: 1158: 1147: 1142: 1138: 1132: 1128: 1122: 1119: 1114: 1111: 1097: 1096: 1082: 1078: 1072: 1068: 1064: 1061: 1058: 1055: 1036: 1033: 1031: 1028: 1020:elliptic space 1006:. Just as the 988: 987: 976: 972: 968: 965: 962: 959: 956: 953: 949: 945: 942: 938: 934: 929: 925: 910: 909: 897: 893: 890: 885: 880: 873: 869: 864: 860: 855: 850: 843: 839: 834: 830: 825: 820: 815: 812: 807: 803: 799: 794: 790: 786: 782: 778: 773: 769: 728: 727: 716: 712: 708: 705: 700: 695: 691: 687: 682: 677: 673: 669: 664: 659: 655: 651: 646: 641: 637: 633: 628: 623: 618: 615: 610: 606: 602: 597: 593: 589: 584: 580: 576: 571: 567: 563: 559: 555: 550: 546: 521: 520: 509: 504: 500: 496: 491: 487: 481: 477: 473: 468: 464: 460: 457: 452: 448: 442: 438: 434: 429: 425: 421: 418: 413: 409: 403: 399: 395: 390: 386: 382: 379: 374: 370: 364: 360: 356: 351: 347: 343: 340: 335: 331: 325: 321: 317: 312: 308: 304: 299: 294: 291: 288: 284: 256: 249: 242: 235: 220: 213: 206: 199: 186: 183: 88: 87: 42: 40: 33: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 6376: 6365: 6362: 6360: 6357: 6355: 6352: 6350: 6347: 6345: 6342: 6340: 6337: 6336: 6334: 6316: 6310: 6309: 6304: 6303:"Hypersphere" 6301: 6296: 6295: 6291: 6284: 6280: 6275: 6270: 6266: 6262: 6257: 6254: 6253:three-sphere. 6249: 6248: 6243: 6239: 6235: 6231: 6230: 6225: 6221: 6220: 6215: 6206: 6202: 6198: 6192: 6188: 6187: 6179: 6176: 6164: 6158: 6154: 6153: 6145: 6142: 6137: 6133: 6129: 6125: 6121: 6117: 6113: 6109: 6102: 6099: 6094: 6090: 6086: 6080: 6076: 6069: 6066: 6061: 6054: 6051: 6046: 6040: 6036: 6032: 6028: 6027: 6022: 6018: 6012: 6009: 6004: 6000: 5996: 5992: 5986: 5983: 5976: 5972: 5969: 5967: 5964: 5962: 5959: 5957: 5953: 5950: 5948: 5945: 5943: 5939: 5935: 5932: 5930: 5928: 5923: 5919: 5916: 5915: 5911: 5909: 5907: 5902: 5900: 5899:Carlo Rovelli 5896: 5892: 5891: 5886: 5885: 5879: 5877: 5873: 5869: 5868:Dionys Burger 5865: 5864: 5859: 5858: 5853: 5846:In literature 5845: 5843: 5837: 5813: 5809: 5803: 5799: 5793: 5789: 5783: 5778: 5775: 5772: 5768: 5763: 5759: 5756: 5753: 5750: 5743: 5742: 5741: 5737: 5713: 5708: 5702: 5699: 5696: 5689: 5685: 5680: 5677: 5673: 5667: 5664: 5661: 5654: 5650: 5645: 5642: 5638: 5634: 5627: 5624: 5621: 5614: 5610: 5605: 5601: 5595: 5592: 5589: 5582: 5578: 5573: 5569: 5562: 5553: 5552: 5551: 5540: 5533: 5529: 5522: 5516: 5511: 5503: 5498: 5492: 5488: 5480: 5475: 5470: 5467: 5448: 5443: 5435: 5431: 5427: 5424: 5419: 5415: 5407: 5403: 5399: 5396: 5391: 5387: 5383: 5374: 5370: 5366: 5363: 5358: 5354: 5346: 5342: 5338: 5335: 5330: 5326: 5316: 5308: 5303: 5299: 5295: 5292: 5287: 5283: 5279: 5276: 5271: 5267: 5263: 5258: 5254: 5246: 5245: 5244: 5242: 5237: 5231: 5226: 5221: 5218: 5212: 5206: 5201: 5200: 5194: 5189: 5185: 5180: 5174: 5168: 5163: 5158: 5157: 5151: 5146: 5142: 5135: 5129: 5124: 5120: 5116: 5111: 5106: 5102: 5097: 5091: 5086: 5078: 5076: 5049: 5041: 5034: 5029: 5017: 5016: 5015: 5012: 5007: 5002: 4997: 4988: 4982:(−1, 0, 0, 0) 4978: 4958: 4954: 4948: 4944: 4940: 4935: 4931: 4927: 4922: 4918: 4913: 4904: 4900: 4896: 4893: 4889: 4884: 4872: 4871: 4870: 4863: 4853: 4846: 4839: 4835: 4807: 4804: 4794: 4791: 4788: 4782: 4778: 4769: 4761: 4755: 4752: 4742: 4736: 4728: 4720: 4714: 4711: 4704: 4696: 4690: 4687: 4684: 4677: 4673: 4670: 4663: 4662: 4661: 4636: 4632: 4626: 4622: 4618: 4613: 4609: 4605: 4600: 4596: 4591: 4582: 4578: 4574: 4571: 4567: 4562: 4550: 4549: 4548: 4545: 4535: 4528: 4521: 4514: 4510: 4504: 4498: 4494: 4488: 4484: 4478: 4474: 4461: 4454: 4447: 4442: 4434: 4424: 4417: 4410: 4406: 4378: 4375: 4365: 4362: 4356: 4352: 4343: 4335: 4329: 4326: 4316: 4310: 4302: 4294: 4288: 4285: 4278: 4270: 4264: 4261: 4254: 4250: 4247: 4240: 4239: 4238: 4235: 4225:(−1, 0, 0, 0) 4222: 4218: 4212: 4207: 4199: 4197: 4191: 4182: 4169: 4160: 4152:In this case 4132: 4129: 4126: 4123: 4113: 4109: 4105: 4100: 4096: 4088: 4084: 4080: 4078: 4071: 4067: 4059: 4056: 4053: 4043: 4039: 4035: 4030: 4026: 4018: 4014: 4010: 4008: 4001: 3997: 3985: 3984: 3983: 3981: 3962: 3957: 3953: 3949: 3946: 3941: 3937: 3933: 3930: 3927: 3924: 3920: 3917: 3914: 3911: 3908: 3905: 3902: 3899: 3896: 3889: 3888: 3887: 3868: 3863: 3859: 3855: 3851: 3848: 3843: 3839: 3835: 3830: 3825: 3821: 3817: 3813: 3810: 3805: 3801: 3797: 3792: 3788: 3784: 3781: 3776: 3772: 3768: 3761: 3760: 3759: 3756: 3754: 3724: 3715: 3710: 3701: 3694: 3662: 3661: 3656: 3652: 3644: 3635: 3629: 3610: 3605: 3601: 3592: 3588: 3579: 3575: 3567: 3566: 3565: 3564: 3552: 3543: 3497: 3494: 3491: 3488: 3483: 3479: 3475: 3472: 3469: 3467: 3460: 3456: 3448: 3445: 3442: 3437: 3433: 3429: 3426: 3423: 3421: 3414: 3410: 3402: 3399: 3396: 3391: 3387: 3383: 3380: 3377: 3375: 3368: 3364: 3356: 3353: 3350: 3345: 3341: 3337: 3334: 3331: 3329: 3322: 3318: 3306: 3305: 3304: 3301: 3277: 3274: 3271: 3268: 3261: 3257: 3252: 3248: 3244: 3242: 3235: 3231: 3223: 3220: 3217: 3210: 3206: 3201: 3197: 3193: 3191: 3184: 3180: 3168: 3167: 3166: 3163: 3156: 3149: 3142: 3136: 3126: 3119: 3115: 3104: 3098: 3092: 3086: 3081: 3076: 3069: 3067: 3064: 3054: 3045: 3039: 3019: 3014: 3010: 3006: 3003: 2998: 2994: 2990: 2987: 2982: 2978: 2974: 2969: 2965: 2961: 2956: 2953: 2949: 2945: 2942: 2935: 2934: 2933: 2908: 2902: 2899: 2896: 2893: 2890: 2887: 2881: 2878: 2872: 2869: 2866: 2863: 2860: 2857: 2851: 2848: 2842: 2839: 2836: 2830: 2827: 2820: 2819: 2818: 2811: 2805: 2799: 2794: 2771: 2768: 2765: 2762: 2759: 2756: 2753: 2750: 2747: 2742: 2739: 2735: 2731: 2728: 2721: 2720: 2719: 2717: 2709: 2690: 2687: 2684: 2681: 2678: 2675: 2672: 2669: 2666: 2661: 2657: 2654: 2651: 2647: 2644: 2639: 2635: 2630: 2624: 2620: 2616: 2613: 2610: 2603: 2602: 2601: 2599: 2579: 2574: 2568: 2564: 2560: 2556: 2553: 2548: 2544: 2540: 2535: 2531: 2527: 2523: 2519: 2516: 2511: 2507: 2503: 2498: 2494: 2490: 2486: 2480: 2476: 2472: 2467: 2463: 2459: 2452: 2451: 2450: 2448: 2443: 2421: 2418: 2415: 2412: 2353: 2350: 2347: 2344: 2341: 2338: 2335: 2332: 2329: 2326: 2323: 2321: 2314: 2310: 2302: 2299: 2296: 2293: 2290: 2287: 2284: 2281: 2278: 2275: 2272: 2270: 2263: 2259: 2251: 2248: 2245: 2242: 2239: 2236: 2233: 2230: 2228: 2221: 2217: 2209: 2206: 2203: 2200: 2197: 2195: 2188: 2184: 2172: 2171: 2170: 2166: 2162: 2158: 2151: 2146: 2141: 2136: 2128: 2126: 2124: 2120: 2115: 2110: 2106: 2101: 2091: 2084: 2077: 2070: 2064: 2055: 2053: 2051: 2046: 2040: 2035: 2033: 2008: 2006: 1997: 1995: 1991: 1987: 1985: 1981: 1977: 1976:topologically 1969: 1967: 1961: 1959: 1956: 1952: 1946: 1940: 1935: 1910: 1907: 1897: 1892: 1888: 1884: 1881: 1876: 1872: 1865: 1862: 1859: 1851: 1847: 1843: 1838: 1834: 1823: 1822: 1821: 1818: 1812: 1807: 1804:known as the 1803: 1798: 1792: 1788: 1784: 1779: 1777: 1769: 1765: 1761: 1757: 1753: 1749: 1748:vector fields 1744: 1742: 1738: 1734: 1729: 1718: 1703: 1699: 1695: 1690: 1685: 1680: 1675: 1671: 1663: 1653: 1649: 1643: 1636: 1632: 1626: 1619: 1612: 1608: 1602: 1595: 1591: 1585: 1578: 1574: 1568: 1564: 1558: 1554: 1548: 1544: 1538: 1534: 1528: 1524: 1518: 1514: 1508: 1504: 1498: 1494: 1491: 1487: 1484: 1481: 1478: 1474: 1469: 1463: 1462: 1458: 1455: 1452: 1449: 1446: 1443: 1440: 1437: 1434: 1431: 1428: 1425: 1422: 1419: 1416: 1413: 1410: 1405: 1404: 1400: 1393: 1391: 1387: 1381: 1374: 1362: 1354: 1344: 1339: 1337: 1328: 1313: 1309: 1304: 1299: 1295: 1285: 1281: 1276: 1269: 1263: 1259: 1247: 1243: 1233: 1228: 1226: 1222: 1217: 1212: 1207: 1205: 1204:homeomorphism 1201: 1197: 1193: 1189: 1185: 1181: 1173: 1171: 1167: 1164: 1145: 1140: 1136: 1130: 1126: 1120: 1117: 1112: 1109: 1102: 1101: 1100: 1080: 1076: 1070: 1066: 1062: 1059: 1056: 1053: 1046: 1045: 1044: 1034: 1029: 1027: 1025: 1021: 1017: 1013: 1009: 1005: 1004:division ring 1001: 997: 993: 974: 970: 966: 963: 957: 951: 943: 940: 936: 932: 927: 923: 915: 914: 913: 895: 891: 888: 883: 871: 867: 858: 853: 841: 837: 828: 823: 813: 805: 801: 797: 792: 788: 780: 776: 771: 767: 759: 758: 757: 754: 749: 744: 739: 734: 714: 710: 706: 703: 698: 693: 689: 685: 680: 675: 671: 667: 662: 657: 653: 649: 644: 639: 635: 631: 626: 616: 608: 604: 600: 595: 591: 587: 582: 578: 574: 569: 565: 557: 553: 548: 544: 536: 535: 534: 531: 526: 525:unit 3-sphere 507: 502: 498: 494: 489: 479: 475: 471: 466: 462: 455: 450: 440: 436: 432: 427: 423: 416: 411: 401: 397: 393: 388: 384: 377: 372: 362: 358: 354: 349: 345: 338: 333: 323: 319: 315: 310: 306: 297: 292: 289: 286: 282: 274: 273: 272: 269: 264: 255: 248: 241: 234: 219: 212: 205: 198: 192: 184: 182: 180: 175: 173: 169: 165: 161: 159: 154: 150: 146: 142: 138: 130: 126: 121: 114: 110: 102: 98: 94: 84: 81: 73: 63: 59: 53: 52: 46: 41: 32: 31: 19: 6314: 6306: 6274:2003.09236v2 6264: 6260: 6251: 6246: 6234:the original 6228: 6185: 6178: 6168:13 September 6166:. Retrieved 6151: 6144: 6136:the original 6115: 6111: 6101: 6074: 6068: 6053: 6025: 6011: 5998: 5994: 5985: 5926: 5905: 5903: 5888: 5882: 5880: 5875: 5871: 5861: 5855: 5849: 5835: 5828: 5735: 5728: 5550:in the form 5538: 5531: 5527: 5523: 5509: 5499: 5473: 5463: 5235: 5229: 5222: 5216: 5210: 5204: 5197: 5192: 5178: 5172: 5166: 5155: 5147: 5140: 5127: 5109: 5095: 5089: 5082: 5074: 5010: 5000: 4992:(1, 0, 0, 0) 4986: 4976: 4973: 4861: 4851: 4844: 4837: 4833: 4830: 4660:is given by 4654:(1, 0, 0, 0) 4651: 4543: 4533: 4526: 4519: 4512: 4508: 4502: 4496: 4492: 4486: 4482: 4476: 4472: 4459: 4452: 4445: 4440: 4432: 4422: 4415: 4408: 4404: 4401: 4233: 4216: 4210: 4203: 4189: 4180: 4167: 4158: 4151: 3977: 3885: 3757: 3733:equals 0 or 3722: 3713: 3699: 3692: 3666: 3658: 3654: 3650: 3642: 3633: 3550: 3541: 3516: 3299: 3296: 3161: 3154: 3147: 3140: 3134: 3124: 3117: 3113: 3109: 3102: 3096: 3090: 3084: 3062: 3046: 3037: 3034: 2932:is given by 2923: 2813:so any such 2809: 2797: 2786: 2705: 2595: 2447:round metric 2444: 2438:equals 0 or 2372: 2164: 2160: 2156: 2149: 2139: 2132: 2118: 2113: 2099: 2089: 2082: 2075: 2068: 2062: 2059: 2047: 2036: 2009: 2001: 1992: 1988: 1973: 1965: 1954: 1950: 1944: 1938: 1931: 1816: 1810: 1796: 1790: 1787:circle group 1780: 1745: 1741:circle group 1730: 1716: 1688: 1678: 1667: 1651: 1641: 1634: 1624: 1617: 1610: 1600: 1593: 1583: 1576: 1566: 1556: 1546: 1536: 1526: 1516: 1506: 1496: 1489: 1472: 1467: 1398: 1379: 1372: 1360: 1352: 1340: 1326: 1312:Dehn filling 1302: 1296:. Initially 1283: 1279: 1274: 1261: 1257: 1245: 1241: 1229: 1224: 1215: 1208: 1177: 1168: 1160: 1098: 1038: 989: 911: 752: 742: 732: 729: 529: 524: 522: 271:) such that 267: 253: 246: 239: 232: 217: 210: 203: 196: 188: 176: 171: 167: 157: 148: 144: 140: 134: 128: 124: 112: 108: 76: 67: 48: 18:Three-sphere 6359:Quaternions 5952:Hopf bundle 5876:hypersphere 5491:determinant 5487:square root 5223:By using a 4444:‖ = 3563:Hopf bundle 2708:quaternions 2598:volume form 1934:orbit space 1806:Hopf bundle 1760:Lie algebra 1314:with slope 1008:unit circle 992:quaternions 748:quaternions 225:and radius 191:coordinates 141:hypersphere 137:mathematics 62:introducing 6333:Categories 5977:References 5938:polychoron 5872:oversphere 5863:Sphereland 5515:isomorphic 5119:nonabelian 5117:. It is a 4221:hyperplane 3660:flat torus 1692:induces a 1384:) are all 1345:, we have 1341:As to the 1163:hyperplane 1030:Properties 185:Definition 179:3-manifold 45:references 6308:MathWorld 6205:893872366 6093:910917227 5934:tesseract 5790:α 5769:∑ 5760:⁡ 5703:η 5700:⁡ 5686:ξ 5678:− 5668:η 5665:⁡ 5651:ξ 5643:− 5635:− 5628:η 5625:⁡ 5611:ξ 5596:η 5593:⁡ 5579:ξ 5466:injective 5425:− 5384:− 5312:↦ 5184:octonions 5115:Lie group 5046:‖ 5039:‖ 4897:− 4789:− 4766:‖ 4759:‖ 4725:‖ 4718:‖ 4701:‖ 4694:‖ 4685:− 4379:− 4340:‖ 4333:‖ 4299:‖ 4292:‖ 4275:‖ 4268:‖ 4265:− 4130:η 4127:⁡ 4110:ξ 4106:− 4097:ξ 4060:η 4057:⁡ 4040:ξ 4027:ξ 3954:ξ 3947:∧ 3938:ξ 3931:∧ 3928:η 3921:η 3918:⁡ 3912:η 3909:⁡ 3860:ξ 3852:η 3849:⁡ 3822:ξ 3814:η 3811:⁡ 3789:η 3598:→ 3585:→ 3495:η 3492:⁡ 3480:ξ 3476:⁡ 3449:η 3446:⁡ 3434:ξ 3430:⁡ 3403:η 3400:⁡ 3388:ξ 3384:⁡ 3357:η 3354:⁡ 3342:ξ 3338:⁡ 3275:η 3272:⁡ 3258:ξ 3224:η 3221:⁡ 3207:ξ 3165:we write 2957:ψ 2954:τ 2903:φ 2900:⁡ 2894:θ 2891:⁡ 2873:φ 2870:⁡ 2864:θ 2861:⁡ 2843:θ 2840:⁡ 2828:τ 2772:ψ 2769:⁡ 2763:τ 2757:ψ 2754:⁡ 2743:ψ 2740:τ 2688:φ 2682:∧ 2679:θ 2673:∧ 2670:ψ 2658:θ 2655:⁡ 2648:ψ 2645:⁡ 2565:φ 2557:θ 2554:⁡ 2532:θ 2520:ψ 2517:⁡ 2495:ψ 2422:ψ 2419:⁡ 2354:φ 2351:⁡ 2345:θ 2342:⁡ 2336:ψ 2333:⁡ 2303:φ 2300:⁡ 2294:θ 2291:⁡ 2285:ψ 2282:⁡ 2252:θ 2249:⁡ 2243:ψ 2240:⁡ 2210:ψ 2207:⁡ 2109:longitude 2050:Lie group 2032:conformal 1911:∈ 1908:λ 1905:∀ 1898:λ 1882:λ 1863:λ 1860:⋅ 1733:Lie group 1704:equal to 1266:are both 1184:connected 1127:π 1067:π 961:‖ 955:‖ 944:∈ 814:∈ 746:) or the 617:∈ 472:− 433:− 394:− 355:− 316:− 283:∑ 261:in real, 129:2-spheres 101:conformal 70:June 2016 6325:-sphere. 6023:(1988). 6005:: 57–78. 5922:2-sphere 5918:1-sphere 5912:See also 5857:Flatland 5507:. Thus, 4984:and the 4438:‖ 3655:toroidal 3651:poloidal 2596:and the 2169:, where 2119:at least 2105:latitude 1942:. Since 1752:sections 1298:Poincaré 1270:, while 1188:manifold 145:3-sphere 125:3-sphere 6364:Spheres 6120:Bibcode 5942:simplex 5929:-sphere 5738:∈ SU(2) 5489:of the 5150:spheres 5123:compact 3749:⁠ 3735:⁠ 3687:⁠ 3673:⁠ 3537:⁠ 3523:⁠ 3041:0,1,2,3 1785:of the 1768:trivial 1754:of its 1721:⁠ 1707:⁠ 1334:on any 1331:⁠ 1317:⁠ 1180:compact 1000:versors 170:, or a 160:-sphere 109:surface 58:improve 6203:  6193:  6159:  6091:  6081:  6041:  5225:matrix 5214:, and 5164:, and 5105:smooth 4831:where 4402:where 4156:, and 3753:circle 3539:, and 3035:where 2787:where 2716:versor 2385:, and 2373:where 1970:Gluing 1783:action 1724:where 1694:metric 1682:. The 1363:) = {} 1286:) = {} 172:gongyl 168:4-ball 153:sphere 113:shadow 47:, but 6269:arXiv 6035:Nauka 5895:Dante 5731:SU(2) 5548:SU(2) 5519:SU(2) 5505:SU(2) 5471:from 5139:U(1, 5134:Sp(1) 5101:group 4996:atlas 4178:) of 3709:torus 3663:case. 3517:Here 3047:When 2924:With 2791:is a 1984:balls 1355:) = π 149:glome 147:, or 6315:Note 6201:OCLC 6191:ISBN 6170:2021 6157:ISBN 6089:OCLC 6079:ISBN 6039:ISBN 5995:Acta 4436:and 3720:and 3653:and 3548:and 3160:) ∈ 2800:= −1 2445:The 2401:and 2377:and 2121:two 2107:and 1932:The 1365:and 1336:knot 1250:and 1230:The 996:norm 139:, a 6279:doi 6128:doi 5904:In 5854:'s 5850:In 5757:exp 5697:sin 5662:cos 5622:cos 5590:sin 5517:to 5137:or 4998:on 4869:to 4836:= ( 4547:to 4541:in 4511:= ( 4407:= ( 4237:as 4231:in 4208:of 4187:or 4124:cos 4054:sin 3915:cos 3906:sin 3840:cos 3802:sin 3489:cos 3473:sin 3443:cos 3427:cos 3397:sin 3381:sin 3351:sin 3335:cos 3303:as 3269:cos 3218:sin 3138:in 3088:to 3082:of 2897:sin 2888:sin 2867:cos 2858:sin 2837:cos 2808:Im 2766:sin 2751:cos 2652:sin 2636:sin 2600:by 2545:sin 2508:sin 2416:sin 2348:sin 2339:sin 2330:sin 2297:cos 2288:sin 2279:sin 2246:cos 2237:sin 2204:cos 2147:on 2137:on 2095:= 1 1978:by 1794:on 1743:). 1686:on 1676:of 1459:16 1382:≥ 4 1213:of 1043:is 994:of 912:or 189:In 135:In 6335:: 6305:. 6277:. 6263:. 6250:. 6199:. 6126:. 6116:47 6114:. 6110:. 6087:. 6029:. 6019:; 6001:. 5999:12 5997:. 5954:, 5940:, 5936:, 5924:, 5920:, 5878:. 5537:, 5530:, 5521:. 5497:. 5243:: 5220:. 5208:, 5145:. 5121:, 5107:, 5087:, 4850:, 4843:, 4532:, 4525:, 4518:, 4495:+ 4485:+ 4475:= 4458:+ 4451:+ 4421:, 4414:, 3755:. 3698:, 3153:, 3123:, 3116:, 3066:. 2718:: 2397:, 2163:, 2159:, 2088:+ 2081:+ 2074:+ 2028:NP 2012:xy 1953:× 1778:. 1614:84 1597:12 1560:15 1520:12 1456:15 1453:14 1450:13 1447:12 1444:11 1441:10 1392:. 1282:, 1260:, 1244:, 1227:. 1182:, 1026:. 533:: 252:, 245:, 238:, 216:, 209:, 202:, 181:. 174:. 143:, 6323:n 6319:n 6311:. 6285:. 6281:: 6271:: 6265:8 6207:. 6172:. 6130:: 6122:: 6095:. 6062:. 6047:. 5927:n 5839:1 5836:α 5831:U 5814:. 5810:) 5804:i 5800:J 5794:i 5784:3 5779:1 5776:= 5773:i 5764:( 5754:= 5751:U 5736:U 5714:. 5709:) 5690:1 5681:i 5674:e 5655:2 5646:i 5639:e 5615:2 5606:i 5602:e 5583:1 5574:i 5570:e 5563:( 5544:) 5542:2 5539:ξ 5535:1 5532:ξ 5528:η 5526:( 5510:S 5495:q 5483:q 5474:H 5449:. 5444:) 5436:2 5432:x 5428:i 5420:1 5416:x 5408:4 5404:x 5400:i 5397:+ 5392:3 5388:x 5375:4 5371:x 5367:i 5364:+ 5359:3 5355:x 5347:2 5343:x 5339:i 5336:+ 5331:1 5327:x 5317:( 5309:k 5304:4 5300:x 5296:+ 5293:j 5288:3 5284:x 5280:+ 5277:i 5272:2 5268:x 5264:+ 5259:1 5255:x 5236:S 5230:H 5217:S 5211:S 5205:S 5193:S 5179:S 5173:S 5167:S 5156:S 5143:) 5141:H 5128:S 5110:S 5096:S 5090:S 5059:u 5050:2 5042:u 5035:1 5030:= 5026:v 5011:S 5001:S 4987:v 4977:u 4959:. 4955:) 4949:3 4945:x 4941:, 4936:2 4932:x 4928:, 4923:1 4919:x 4914:( 4905:0 4901:x 4894:1 4890:1 4885:= 4881:v 4867:p 4862:R 4857:) 4855:3 4852:v 4848:2 4845:v 4841:1 4838:v 4834:v 4812:v 4808:+ 4805:1 4799:v 4795:+ 4792:1 4783:= 4779:) 4770:2 4762:v 4756:+ 4753:1 4747:v 4743:2 4737:, 4729:2 4721:v 4715:+ 4712:1 4705:2 4697:v 4691:+ 4688:1 4678:( 4674:= 4671:p 4658:p 4637:. 4633:) 4627:3 4623:x 4619:, 4614:2 4610:x 4606:, 4601:1 4597:x 4592:( 4583:0 4579:x 4575:+ 4572:1 4568:1 4563:= 4559:u 4544:S 4539:) 4537:3 4534:x 4530:2 4527:x 4523:1 4520:x 4516:0 4513:x 4509:p 4503:k 4500:3 4497:u 4493:j 4490:2 4487:u 4483:i 4480:1 4477:u 4473:u 4468:p 4463:3 4460:u 4456:2 4453:u 4449:1 4446:u 4441:u 4433:R 4428:) 4426:3 4423:u 4419:2 4416:u 4412:1 4409:u 4405:u 4383:u 4376:1 4370:u 4366:+ 4363:1 4357:= 4353:) 4344:2 4336:u 4330:+ 4327:1 4321:u 4317:2 4311:, 4303:2 4295:u 4289:+ 4286:1 4279:2 4271:u 4262:1 4255:( 4251:= 4248:p 4234:S 4229:p 4217:R 4211:S 4193:2 4190:ξ 4184:1 4181:ξ 4176:π 4171:2 4168:ξ 4162:1 4159:ξ 4154:η 4133:. 4119:) 4114:1 4101:2 4093:( 4089:i 4085:e 4081:= 4072:2 4068:z 4049:) 4044:2 4036:+ 4031:1 4023:( 4019:i 4015:e 4011:= 4002:1 3998:z 3963:. 3958:2 3950:d 3942:1 3934:d 3925:d 3903:= 3900:V 3897:d 3869:2 3864:2 3856:d 3844:2 3836:+ 3831:2 3826:1 3818:d 3806:2 3798:+ 3793:2 3785:d 3782:= 3777:2 3773:s 3769:d 3746:2 3743:/ 3739:π 3731:η 3726:2 3723:ξ 3717:1 3714:ξ 3705:) 3703:2 3700:ξ 3696:1 3693:ξ 3691:( 3684:2 3681:/ 3677:π 3669:η 3646:2 3643:ξ 3637:1 3634:ξ 3611:. 3606:2 3602:S 3593:3 3589:S 3580:1 3576:S 3559:π 3554:2 3551:ξ 3545:1 3542:ξ 3534:2 3531:/ 3527:π 3519:η 3498:. 3484:2 3470:= 3461:3 3457:x 3438:2 3424:= 3415:2 3411:x 3392:1 3378:= 3369:1 3365:x 3346:1 3332:= 3323:0 3319:x 3300:R 3278:. 3262:2 3253:i 3249:e 3245:= 3236:2 3232:z 3211:1 3202:i 3198:e 3194:= 3185:1 3181:z 3162:C 3158:2 3155:z 3151:1 3148:z 3146:( 3141:C 3135:S 3130:) 3128:2 3125:ξ 3121:1 3118:ξ 3114:η 3112:( 3103:S 3097:R 3091:R 3085:S 3063:ψ 3061:2 3057:τ 3049:q 3038:x 3020:k 3015:3 3011:x 3007:+ 3004:j 2999:2 2995:x 2991:+ 2988:i 2983:1 2979:x 2975:+ 2970:0 2966:x 2962:= 2950:e 2946:= 2943:q 2930:q 2926:τ 2909:k 2906:) 2885:( 2882:+ 2879:j 2876:) 2855:( 2852:+ 2849:i 2846:) 2834:( 2831:= 2815:τ 2810:H 2798:τ 2789:τ 2760:+ 2748:= 2736:e 2732:= 2729:q 2712:q 2691:. 2685:d 2676:d 2667:d 2662:) 2640:2 2631:( 2625:3 2621:r 2617:= 2614:V 2611:d 2580:] 2575:) 2569:2 2561:d 2549:2 2541:+ 2536:2 2528:d 2524:( 2512:2 2504:+ 2499:2 2491:d 2487:[ 2481:2 2477:r 2473:= 2468:2 2464:s 2460:d 2440:π 2436:ψ 2413:r 2403:φ 2399:θ 2395:ψ 2391:π 2387:φ 2383:π 2379:θ 2375:ψ 2327:r 2324:= 2315:3 2311:x 2276:r 2273:= 2264:2 2260:x 2234:r 2231:= 2222:1 2218:x 2201:r 2198:= 2189:0 2185:x 2167:) 2165:φ 2161:θ 2157:ψ 2155:( 2150:S 2140:S 2114:S 2100:S 2093:3 2090:x 2086:2 2083:x 2079:1 2076:x 2072:0 2069:x 2063:S 2043:π 2024:P 2020:N 2016:P 1955:S 1951:S 1945:S 1939:S 1928:. 1915:T 1901:) 1893:2 1889:z 1885:, 1877:1 1873:z 1869:( 1866:= 1857:) 1852:2 1848:z 1844:, 1839:1 1835:z 1831:( 1817:C 1811:S 1797:S 1791:T 1772:n 1750:( 1726:r 1717:r 1713:/ 1710:1 1689:R 1679:R 1655:6 1652:Z 1645:2 1642:Z 1640:⊕ 1638:2 1635:Z 1628:2 1625:Z 1623:⊕ 1621:2 1618:Z 1616:⊕ 1611:Z 1604:2 1601:Z 1599:⊕ 1594:Z 1587:2 1584:Z 1582:⊕ 1580:2 1577:Z 1570:2 1567:Z 1557:Z 1550:3 1547:Z 1540:2 1537:Z 1530:2 1527:Z 1517:Z 1510:2 1507:Z 1500:2 1497:Z 1490:Z 1485:0 1482:0 1479:0 1475:) 1473:S 1471:( 1468:k 1465:π 1438:9 1435:8 1432:7 1429:6 1426:5 1423:4 1420:3 1417:2 1414:1 1411:0 1407:k 1399:S 1380:k 1375:) 1373:S 1371:( 1369:3 1367:π 1361:S 1359:( 1357:2 1353:S 1351:( 1349:1 1347:π 1327:n 1323:/ 1320:1 1303:S 1290:i 1284:Z 1280:S 1278:( 1275:i 1272:H 1264:) 1262:Z 1258:S 1256:( 1254:3 1252:H 1248:) 1246:Z 1242:S 1240:( 1238:0 1236:H 1216:R 1146:. 1141:4 1137:r 1131:2 1121:2 1118:1 1113:= 1110:H 1081:3 1077:r 1071:2 1063:2 1060:= 1057:V 1054:S 1041:r 975:. 971:} 967:1 964:= 958:q 952:: 948:H 941:q 937:{ 933:= 928:3 924:S 896:} 892:1 889:= 884:2 879:| 872:2 868:z 863:| 859:+ 854:2 849:| 842:1 838:z 833:| 829:: 824:2 819:C 811:) 806:2 802:z 798:, 793:1 789:z 785:( 781:{ 777:= 772:3 768:S 753:H 750:( 743:C 740:( 733:R 715:. 711:} 707:1 704:= 699:2 694:3 690:x 686:+ 681:2 676:2 672:x 668:+ 663:2 658:1 654:x 650:+ 645:2 640:0 636:x 632:: 627:4 622:R 614:) 609:3 605:x 601:, 596:2 592:x 588:, 583:1 579:x 575:, 570:0 566:x 562:( 558:{ 554:= 549:3 545:S 530:S 508:. 503:2 499:r 495:= 490:2 486:) 480:3 476:C 467:3 463:x 459:( 456:+ 451:2 447:) 441:2 437:C 428:2 424:x 420:( 417:+ 412:2 408:) 402:1 398:C 389:1 385:x 381:( 378:+ 373:2 369:) 363:0 359:C 350:0 346:x 342:( 339:= 334:2 330:) 324:i 320:C 311:i 307:x 303:( 298:3 293:0 290:= 287:i 268:R 265:( 259:) 257:3 254:x 250:2 247:x 243:1 240:x 236:0 233:x 231:( 227:r 223:) 221:3 218:C 214:2 211:C 207:1 204:C 200:0 197:C 195:( 158:n 131:) 83:) 77:( 72:) 68:( 54:. 20:)

Index

Three-sphere
references
inline citations
improve
introducing
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Stereographic projection
conformal

mathematics
sphere
n-sphere
Euclidean space
3-manifold
coordinates
4-dimensional space
complex dimensions
quaternions
quaternions
norm
versors
division ring
unit circle
polar coordinates
polar decomposition of a quaternion
elliptic space
Georges Lemaître
hyperplane
compact

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