Knowledge (XXG)

Torus

Source 📝

1936: 5521: 4245:(twice continuously differentiable) embedding of a flat torus into 3-space. (The idea of the proof is to take a large sphere containing such a flat torus in its interior, and shrink the radius of the sphere until it just touches the torus for the first time. Such a point of contact must be a tangency. But that would imply that part of the torus, since it has zero curvature everywhere, must lie strictly outside the sphere, which is a contradiction.) On the other hand, according to the 5268: 4360:, yielding a so-called "smooth fractal". The key to obtain the smoothness of this corrugated torus is to have the amplitudes of successive corrugations decreasing faster than their "wavelengths". (These infinitely recursive corrugations are used only for embedding into three dimensions; they are not an intrinsic feature of the flat torus.) This is the first time that any such embedding was defined by explicit equations or depicted by computer graphics. 4257: 4555: 4544: 426: 3163: 4650: 403: 380: 3402: 1876: 4579: 51: 448: 75: 3378: 647: 1584: 4957: 59: 5131: 1499: 4478:
two-tori. (And so the torus itself is the surface of genus 1.) To form a connected sum of two surfaces, remove from each the interior of a disk and "glue" the surfaces together along the boundary circles. (That is, merge the two boundary circles so they become just one circle.) To form the connected
3643:
everywhere. It is flat in the same sense that the surface of a cylinder is flat. In 3 dimensions, one can bend a flat sheet of paper into a cylinder without stretching the paper, but this cylinder cannot be bent into a torus without stretching the paper (unless some regularity and differentiability
2413:
that circles the torus' "hole" (say, a circle that traces out a particular latitude) and then circles the torus' "body" (say, a circle that traces out a particular longitude) can be deformed to a path that circles the body and then the hole. So, strictly 'latitudinal' and strictly 'longitudinal'
2417:
If a torus is punctured and turned inside out then another torus results, with lines of latitude and longitude interchanged. This is equivalent to building a torus from a cylinder, by joining the circular ends together, in two ways: around the outside like joining two ends of a garden hose, or
3357:
whose top and bottom faces are connected with a 1/3 twist (120°): the 3-dimensional interior corresponds to the points on the 3-torus where all 3 coordinates are distinct, the 2-dimensional face corresponds to points with 2 coordinates equal and the 3rd different, while the 1-dimensional edge
462: 2404: 1514:, obtained from cutting the tube along the plane of a small circle, and unrolling it by straightening out (rectifying) the line running around the center of the tube. The losses in surface area and volume on the inner side of the tube exactly cancel out the gains on the outer side. 5248: 5478: 4184: 1871:{\displaystyle {\begin{aligned}A&=4\pi ^{2}\left({\frac {p+q}{2}}\right)\left({\frac {p-q}{2}}\right)=\pi ^{2}(p+q)(p-q),\\V&=2\pi ^{2}\left({\frac {p+q}{2}}\right)\left({\frac {p-q}{2}}\right)^{2}={\tfrac {1}{4}}\pi ^{2}(p+q)(p-q)^{2}.\end{aligned}}} 1318: 4824: 4973:, 1), its homotopy equivalences, up to homotopy, can be identified with automorphisms of the fundamental group); all homotopy equivalences of the torus can be realized by homeomorphisms – every homotopy equivalence is homotopic to a homeomorphism. 5015: 2612: 4431:
to a) the square torus (total angle = π) and b) the hexagonal torus (total angle = 2π/3). These are the only conformal equivalence classes of flat tori that have any conformal automorphisms other than those generated by translations and negation.
2473: 2418:
through the inside like rolling a sock (with the toe cut off). Additionally, if the cylinder was made by gluing two opposite sides of a rectangle together, choosing the other two sides instead will cause the same reversal of orientation.
1079: 1289: 921: 341:
An example of a torus can be constructed by taking a rectangular strip of flexible material such as rubber, and joining the top edge to the bottom edge, and the left edge to the right edge, without any half-twists (compare
4419:
along their (identical) boundaries, where each triangle has angles of π/2, π/3, and 0. As a result the area of each triangle can be calculated as π - (π/2 + π/3 + 0) = π/6, so it follows that the compactified moduli space
5236:, the upper bound is tight.) Equivalently, in a torus divided into regions, it is always possible to color the regions using no more than seven colors so that no neighboring regions are the same color. (Contrast with the 3941: 2283: 1589: 1323: 642:{\displaystyle {\begin{aligned}x(\theta ,\varphi )&=(R+r\cos \theta )\cos {\varphi }\\y(\theta ,\varphi )&=(R+r\cos \theta )\sin {\varphi }\\z(\theta ,\varphi )&=r\sin \theta \\\end{aligned}}} 4372:, one says that any two smooth compact geometric surfaces are "conformally equivalent" when there exists a smooth homeomorphism between them that is both angle-preserving and orientation-preserving. The 4402:
by adding one additional point that represents the limiting case as a rectangular torus approaches an aspect ratio of 0 in the limit. The result is that this compactified moduli space is a sphere with
3758: 3267: 5337: 4735: 4392:
may be identified with a punctured sphere that is smooth except for two points that have less angle than 2π (radians) around them: One has total angle = π and the other has total angle = 2π/3.
467: 4030: 3602: 3320: 2659: 2239: 5763: 1911:, and is known as the "poloidal" direction. These terms were first used in a discussion of the Earth's magnetic field, where "poloidal" was used to denote "the direction toward the poles". 699: 3381:
In three dimensions, one can bend a rectangle into a torus, but doing this necessarily affects the distances measured along the surface, as seen by the distortion of the checkered pattern.
4952:{\displaystyle \operatorname {MCG} _{\operatorname {Ho} }(\mathbb {T} ^{n})=\operatorname {Aut} (\pi _{1}(X))=\operatorname {Aut} (\mathbb {Z} ^{n})=\operatorname {GL} (n,\mathbb {Z} ).} 5234: 6360: 5126:{\displaystyle 1\to \operatorname {Homeo} _{0}(\mathbb {T} ^{n})\to \operatorname {Homeo} (\mathbb {T} ^{n})\to \operatorname {MCG} _{\operatorname {TOP} }(\mathbb {T} ^{n})\to 1.} 936: 5188: 2533: 282: 5007: 4793: 4764: 4350: 4313: 4232: 3555: 3517: 3488: 3451: 3115: 3071: 2978: 2938: 2819: 2783: 2750: 2721: 2688: 2137: 2099: 1193: 822: 5267: 3639:
This metric of the square flat torus can also be realised by specific embeddings of the familiar 2-torus into Euclidean 4-space or higher dimensions. Its surface has zero
1494:{\displaystyle {\begin{aligned}A&=\left(2\pi r\right)\left(2\pi R\right)=4\pi ^{2}Rr,\\V&=\left(\pi r^{2}\right)\left(2\pi R\right)=2\pi ^{2}Rr^{2}.\end{aligned}}} 4407:
points each having less than 2π total angle around them. (Such points are termed "cusps".) This additional point will have zero total angle around it. Due to symmetry,
1965: 6109: 4356:
as it is constructed by repeatedly corrugating an ordinary torus. Like fractals, it has no defined Gaussian curvature. However, unlike fractals, it does have defined
4284: 317: 5882: 776: 2262: 813: 745: 722: 118:
with the circle. The main types of toruses include ring toruses, horn toruses, and spindle toruses. A ring torus is sometimes colloquially referred to as a
6028: 284:, and the latter is taken to be the definition in that context. It is a compact 2-manifold of genus 1. The ring torus is one way to embed this space into 6353: 3136: 5505: 5251:
This construction shows the torus divided into seven regions, every one of which touches every other, meaning each must be assigned a unique color.
3386: 2453:
on the 2-torus can be represented as a two-sheeted cover of the 2-sphere. The points on the torus corresponding to the ramification points are the
6140: 4479:
sum of more than two surfaces, successively take the connected sum of two of them at a time until they are all connected. In this sense, a genus
5689:, Author: Kozak Ana Maria, Pompeya Pastorelli Sonia, Verdanega Pedro Emilio, Editorial: McGraw-Hill, Edition 2007, 744 pages, language: Spanish 334:, a torus is any topological space that is homeomorphic to a torus. The surface of a coffee cup and a doughnut are both topological tori with 6346: 5781: 5726: 5686: 4388:" of the torus to contain one point for each conformal equivalence class, with the appropriate topology. It turns out that this moduli space 6299: 6188: 4352:
was found. It is a flat torus in the sense that, as a metric space, it is isometric to a flat square torus. It is similar in structure to a
3812: 2399:{\displaystyle \pi _{1}(\mathbb {T} ^{2})=\pi _{1}(\mathbb {S} ^{1})\times \pi _{1}(\mathbb {S} ^{1})\cong \mathbb {Z} \times \mathbb {Z} .} 5809: 5311:
exactly once. It is a torus because the edges are considered wraparound for the purpose of finding matrices. Its name comes from the
6046: 5718: 5703: 2414:
paths commute. An equivalent statement may be imagined as two shoelaces passing through each other, then unwinding, then rewinding.
1987: 3653: 4806:, the mapping class group can be identified as the action on the first homology (or equivalently, first cohomology, or on the 78:
A ring torus with aspect ratio 3, the ratio between the diameters of the larger (magenta) circle and the smaller (red) circle.
62:
As the distance from the axis of revolution decreases, the ring torus becomes a horn torus, then a spindle torus, and finally
3215: 6069: 5473:{\displaystyle {\begin{pmatrix}n+2\\n-1\end{pmatrix}}+{\begin{pmatrix}n\\n-1\end{pmatrix}}={\tfrac {1}{6}}(n^{3}+3n^{2}+8n)} 3416:
with 1 vertex, 2 orthogonal edges, and one square face. It is seen here stereographically projected into 3-space as a torus.
4179:{\displaystyle T=\left\{(x,y,z,w)\in \mathbb {S} ^{3}\mid x^{2}+y^{2}={\frac {1}{2}},\ z^{2}+w^{2}={\frac {1}{2}}\right\}.} 6050: 5590: 5575: 3205: 1903:
measures the same angle as it does in the spherical system, but is known as the "toroidal" direction. The center point of
163:). If the axis of revolution passes through the center of the circle, the surface is a degenerate torus, a double-covered 4700: 3647:
A simple 4-dimensional Euclidean embedding of a rectangular flat torus (more general than the square one) is as follows:
5284:
with 1s as panels and 0s as holes in the mesh – with consistent orientation, every 3×3 matrix appears exactly once
1312: 4963: 3561: 3279: 2620: 1948: 6499: 5929:
Padgett, Adele (2014). "FUNDAMENTAL GROUPS: MOTIVATION, COMPUTATION METHODS, AND APPLICATIONS" REA Program, Uchicago.
4502:
while a genus one surface (without boundary) is the ordinary torus. The surfaces of higher genus are sometimes called
2160: 1919: 1881: 1958: 1952: 1944: 5835: 4532:
surface is topologically equivalent to either the sphere or the connect sum of some number of tori, disks, and real
654: 4253:
embedding exists. This is solely an existence proof and does not provide explicit equations for such an embedding.
3806:-space requires one to stretch it, in which case it looks like a regular torus. For example, in the following map: 3406: 2786: 2048:
by a family of nested tori in this manner (with two degenerate circles), a fact which is important in the study of
3421: 2147: 701:
representing rotation around the tube and rotation around the torus' axis of revolution, respectively, where the
5969: 5193: 1969: 6535: 5650: 3390: 3365:
in the work of Dmitri Tymoczko and collaborators (Felipe Posada, Michael Kolinas, et al.), being used to model
2274: 2107: 2024: 63: 6162: 2106:
to a topological torus as long as it does not intersect its own axis. A particular homeomorphism is given by
6608: 6539: 4639: 111: 58: 31: 5136:
The mapping class group of higher genus surfaces is much more complicated, and an area of active research.
3636:. This particular flat torus (and any uniformly scaled version of it) is known as the "square" flat torus. 2866:
with multiplication). Group multiplication on the torus is then defined by coordinate-wise multiplication.
6338: 5994: 4803: 4522: 4373: 4246: 3176: 2607:{\displaystyle \mathbb {T} ^{n}=\underbrace {\mathbb {S} ^{1}\times \cdots \times \mathbb {S} ^{1}} _{n}.} 324: 42: 6475: 6417: 5645: 5605: 4013: 2072: 1915: 792: 103: 5520: 5162: 2951:
with an integral inverse; these are just the integral matrices with determinant ±1. Making them act on
2261: 247: 6132: 4983: 4769: 4740: 4326: 4289: 4208: 3531: 3493: 3464: 3427: 3091: 3047: 2954: 2914: 2795: 2759: 2726: 2697: 2664: 2113: 2075: 6597: 6572: 5986: 5580: 5308: 5297: 4977: 4737:
of invertible integer matrices, which can be realized as linear maps on the universal covering space
4601: 3346: 3086: 3026: 3019: 5999: 6567: 6561: 5241: 4694: 4686: 4583: 4573: 4459: 4017: 3520: 3135: 3125: 2450: 2249: 1188: 456: 335: 5909: 6462: 6295: 6192: 6020: 5665: 5620: 5550: 5526: 5312: 5237: 4690: 4455: 4381: 3640: 3523:, as well as the structure of an abelian Lie group. Perhaps the simplest example of this is when 2996: 2446: 130: 6304: 5805: 5930: 6633: 6441: 6324: 6289: 6241: 6101: 6012: 5977: 5858: 5777: 5722: 5714: 5699: 5682: 5483:
parts. (This assumes the pieces may not be rearranged but must remain in place for all cuts.)
5272: 4807: 4412: 4357: 3799: 3780: 2988: 2944: 2941: 2870: 2454: 2270: 2068: 1296: 1074:{\displaystyle \left(x^{2}+y^{2}+z^{2}+R^{2}-r^{2}\right)^{2}=4R^{2}\left(x^{2}+y^{2}\right).} 788: 6423: 6283: 6091: 6081: 6004: 5769: 5153: 4811: 4533: 4416: 4323:(continuously differentiable) embedding of a flat torus into 3-dimensional Euclidean space 4256: 3385: 3354: 3078: 2430: 2008: 1137: 1131: 930: 237: 151: 5791: 4554: 4543: 4262: 295: 6525: 6054: 5787: 5540: 5261: 4529: 4445: 4369: 3784: 3605: 3323: 3038: 2790: 2410: 2151: 1899:
As a torus has, effectively, two center points, the centerpoints of the angles are moved;
1300: 1083:
The three classes of standard tori correspond to the three possible aspect ratios between
816: 285: 198: 6487: 3338: 3155: 1284:{\displaystyle {\textstyle {\bigl (}{\sqrt {x^{2}+y^{2}}}-R{\bigr )}^{2}}+z^{2}<r^{2}} 753: 5990: 3341:, the edge corresponding to the orbifold points where the two coordinates coincide. For 6096: 5615: 5600: 5570: 5555: 5545: 5247: 5157: 5149: 5145: 3772: 3162: 3008: 2897:, which (like tori) are compact connected abelian groups, which are not required to be 2863: 2477: 2422: 2037: 2004: 1292: 916:{\displaystyle {\textstyle {\bigl (}{\sqrt {x^{2}+y^{2}}}-R{\bigr )}^{2}}+z^{2}=r^{2}.} 798: 730: 707: 425: 320: 5693: 4649: 784:
of the torus. The typical doughnut confectionery has an aspect ratio of about 3 to 2.
6627: 6588: 6544: 6530: 6428: 5660: 5635: 5630: 5595: 5565: 5560: 5289: 4980:
of the mapping class group splits (an identification of the torus as the quotient of
4590: 4526: 4471: 4384:. In the case of a torus, the constant curvature must be zero. Then one defines the " 4377: 3366: 2878: 2852: 2845: 2434: 233: 185: 5732: 3377: 6435: 6272: 6024: 5755: 5585: 4697:(the connected components of the homeomorphism group) is surjective onto the group 4559: 4548: 4515: 4511: 4385: 3401: 2904: 2103: 2053: 1308: 780: 402: 379: 343: 6244: 3139:
The configuration space of 2 not necessarily distinct points on the circle is the
1884:
is sometimes used. In traditional spherical coordinates there are three measures,
1521:
of an outermost point on the surface of the torus to the center, and the distance
6215: 3994:. In particular, for certain very specific choices of a square flat torus in the 3420:
A flat torus is a torus with the metric inherited from its representation as the
6315: 6133:"Mathematicians Produce First-Ever Image of Flat Torus in 3D | Mathematics" 3413: 2859: 2458: 2426: 2245: 2061: 926: 193: 115: 38: 4638:
The term "toroidal polyhedron" is also used for higher-genus polyhedra and for
3183:
segment of the right edge of the repeated parallelogram is identified with the
724:
is the distance from the center of the tube to the center of the torus and the
6308: 6277: 5773: 5655: 5625: 5516: 4815: 4597: 4578: 3350: 181: 149:. If the axis of revolution passes twice through the circle, the surface is a 50: 6268: 4795:(this corresponds to integer coefficients) and thus descend to the quotient. 4600:
with the topological type of a torus are called toroidal polyhedra, and have
6603: 6492: 6249: 6163:"Mathematics: first-ever image of a flat torus in 3D – CNRS Web site – CNRS" 6086: 6008: 5866: 5759: 2855: 2830: 2472: 2045: 447: 289: 177: 6105: 6016: 5943: 5861: 3345:= 3 this quotient may be described as a solid torus with cross-section an 201:, rather than a circle, around an axis. A solid torus is a torus plus the 74: 17: 6480: 5831: 4799: 4016:
solid tori subsets with the aforesaid flat torus surface as their common
3995: 3991: 3776: 3362: 3274: 3140: 2898: 2894: 2882: 2848: 2030: 2000: 1117:
corresponds to the horn torus, which in effect is a torus with no "hole".
331: 229: 218: 214: 83: 133:
does not touch the circle, the surface has a ring shape and is called a
5535: 4353: 3168: 142: 4193:
having this partitioning property include the square tori of the form
3936:{\displaystyle (x,y,z)=((R+P\sin v)\cos u,(R+P\sin v)\sin u,P\cos v).} 3212:
ordered, not necessarily distinct points on the circle. Symbolically,
2885:
which is a torus of the largest possible dimension. Such maximal tori
355: 319:
in the plane with itself. This produces a geometric object called the
6388: 5640: 5610: 5300:
of symbols from an alphabet (often just 0 and 1) that contains every
4499: 4488: 2519:.) Recalling that the torus is the product space of two circles, the 2012: 1304: 241: 210: 202: 169: 164: 107: 67: 2821:(with the action being taken as vector addition). Equivalently, the 1880:
As a torus is the product of two circles, a modified version of the
1129:
describes the self-intersecting spindle torus; its inner shell is a
37:
This article is about the mathematical surface. For the volume, see
6166: 5246: 4577: 4255: 3400: 3384: 3376: 3161: 3134: 2471: 2260: 451:
Poloidal direction (red arrow) and toroidal direction (blue arrow)
446: 359:
is a Latin word for "a round, swelling, elevation, protuberance".
222: 176:
Real-world objects that approximate a torus of revolution include
73: 57: 49: 167:. If the revolved curve is not a circle, the surface is called a 4689:(or the subgroup of diffeomorphisms) of the torus is studied in 2873:. This is due in part to the fact that in any compact Lie group 2457:. In fact, the conformal type of the torus is determined by the 6342: 3397:
can be projected into 3-dimensions and rotated on a fixed axis.
4644: 2862:
is a compact abelian Lie group (when identified with the unit
2036:
of radius √2. This topological torus is also often called the
1929: 5768:. Geometry and Computing. Vol. 9. Springer, Heidelberg. 1888:, the distance from the center of the coordinate system, and 1105:, the surface will be the familiar ring torus or anchor ring. 288:, but another way to do this is the Cartesian product of the 5931:
https://math.uchicago.edu/~may/REU2014/REUPapers/Padgett.pdf
4498:
As examples, a genus zero surface (without boundary) is the
2480:
in four dimensions performing a simple rotation through the
5500: 3954:
in the above flat torus parametrization form a unit vector
3771:
are positive constants determining the aspect ratio. It is
3753:{\displaystyle (x,y,z,w)=(R\cos u,R\sin u,P\cos v,P\sin v)} 1517:
Expressing the surface area and the volume by the distance
5765:
A Guide to the Classification Theorem for Compact Surfaces
5498:
1, 2, 6, 13, 24, 40, 62, 91, 128, 174, 230, ... (sequence
2507:
for short. (This is the more typical meaning of the term "
5910:"Applications of the Clifford torus to material textures" 5494:= 0, not covered by the above formulas), are as follows: 4615:= 0. For any number of holes, the formula generalizes to 4427:
The other two cusps occur at the points corresponding in
2911:
are easily constructed from automorphisms of the lattice
2488:
The torus has a generalization to higher dimensions, the
6070:"Doc Madhattan: A flat torus in three dimensional space" 4810:, as these are all naturally isomorphic; also the first 3358:
corresponds to points with all 3 coordinates identical.
2869:
Toroidal groups play an important part in the theory of
1503:
These formulas are the same as for a cylinder of length
205:
inside the torus. Real-world objects that approximate a
6369:
Compact topological surfaces and their immersions in 3D
4661: 3262:{\displaystyle \mathbb {T} ^{n}=(\mathbb {S} ^{1})^{n}} 2889:
have a controlling role to play in theory of connected
2248:
by pasting the opposite edges together, described as a
54:
A ring torus with a selection of circles on its surface
6280:
Fly-through cross-sections of a four-dimensional torus
5418: 5387: 5346: 4012:
above, the torus will partition the 3-sphere into two
2752:
under integral shifts in any coordinate. That is, the
1803: 1198: 827: 5340: 5196: 5165: 5018: 4986: 4827: 4772: 4743: 4703: 4411:
may be constructed by glueing together two congruent
4329: 4292: 4265: 4211: 4033: 3815: 3656: 3564: 3534: 3496: 3467: 3430: 3282: 3273:, not necessarily distinct points is accordingly the 3218: 3094: 3050: 2957: 2917: 2798: 2762: 2729: 2700: 2667: 2661:. The torus discussed above is the standard 2-torus, 2623: 2536: 2286: 2163: 2116: 2078: 1587: 1321: 1196: 939: 825: 801: 756: 733: 710: 657: 465: 298: 250: 2277:
of the fundamental group of the circle with itself:
6581: 6553: 6518: 6509: 6455: 6410: 6381: 6374: 6191:. Math.univ-lyon1.fr. 18 April 2012. Archived from 5009:gives a splitting, via the linear maps, as above): 4730:{\displaystyle \operatorname {GL} (n,\mathbb {Z} )} 5735:Encyclopédie des Formes Mathématiques Remarquables 5472: 5228: 5182: 5125: 5001: 4951: 4787: 4758: 4729: 4344: 4307: 4278: 4226: 4178: 3935: 3752: 3596: 3549: 3511: 3482: 3445: 3314: 3261: 3109: 3065: 2972: 2932: 2813: 2777: 2744: 2715: 2682: 2653: 2606: 2445:The 2-torus double-covers the 2-sphere, with four 2398: 2233: 2131: 2093: 1870: 1493: 1283: 1073: 915: 807: 770: 739: 716: 693: 641: 311: 276: 6286:Visualizing high dimensional data with flat torus 3597:{\displaystyle \mathbb {R} ^{2}/\mathbb {Z} ^{2}} 3315:{\displaystyle \mathbb {T} ^{n}/\mathbb {S} _{n}} 2654:{\displaystyle \mathbb {T} ^{1}=\mathbb {S} ^{1}} 5679:Nociones de Geometría Analítica y Álgebra Lineal 4458:there is a more general family of objects, the " 2234:{\displaystyle (x,y)\sim (x+1,y)\sim (x,y+1),\,} 1957:but its sources remain unclear because it lacks 6074:Proceedings of the National Academy of Sciences 5315:, which can be considered a special case where 4249:, which was proven in the 1950s, an isometric 694:{\displaystyle \theta ,\varphi \in [0,2\pi ),} 6354: 3519:. This gives the quotient the structure of a 1525:of an innermost point to the center (so that 1242: 1201: 1167:, the torus degenerates to the circle radius 1151:, the torus degenerates to the sphere radius 871: 830: 8: 4487:doughnuts stuck together side by side, or a 3322:, which is the quotient of the torus by the 2429:to the fundamental group (this follows from 6309:"Topology of a Twisted Torus – Numberphile" 6515: 6378: 6361: 6347: 6339: 5327:A solid torus of revolution can be cut by 5229:{\displaystyle \chi ({\mathsf {K_{7}}})=7} 5148:is seven, meaning every graph that can be 114:one full revolution about an axis that is 6216:"The Tortuous Geometry of the Flat Torus" 6095: 6085: 5998: 5452: 5436: 5417: 5382: 5341: 5339: 5209: 5204: 5203: 5195: 5172: 5167: 5166: 5164: 5108: 5104: 5103: 5090: 5074: 5070: 5069: 5047: 5043: 5042: 5029: 5017: 4993: 4989: 4988: 4985: 4939: 4938: 4911: 4907: 4906: 4875: 4850: 4846: 4845: 4832: 4826: 4779: 4775: 4774: 4771: 4750: 4746: 4745: 4742: 4720: 4719: 4702: 4376:guarantees that every Riemann surface is 4336: 4332: 4331: 4328: 4299: 4295: 4294: 4291: 4270: 4264: 4218: 4214: 4213: 4210: 4158: 4149: 4136: 4116: 4107: 4094: 4081: 4077: 4076: 4032: 3814: 3655: 3588: 3584: 3583: 3577: 3571: 3567: 3566: 3563: 3541: 3537: 3536: 3533: 3503: 3499: 3498: 3495: 3474: 3470: 3469: 3466: 3437: 3433: 3432: 3429: 3306: 3302: 3301: 3295: 3289: 3285: 3284: 3281: 3253: 3243: 3239: 3238: 3225: 3221: 3220: 3217: 3172:is an example of a torus in music theory. 3101: 3097: 3096: 3093: 3057: 3053: 3052: 3049: 2964: 2960: 2959: 2956: 2924: 2920: 2919: 2916: 2840:-torus in this sense is an example of an 2805: 2801: 2800: 2797: 2769: 2765: 2764: 2761: 2736: 2732: 2731: 2728: 2707: 2703: 2702: 2699: 2674: 2670: 2669: 2666: 2645: 2641: 2640: 2630: 2626: 2625: 2622: 2617:The standard 1-torus is just the circle: 2595: 2583: 2579: 2578: 2562: 2558: 2557: 2553: 2543: 2539: 2538: 2535: 2389: 2388: 2381: 2380: 2368: 2364: 2363: 2353: 2337: 2333: 2332: 2322: 2306: 2302: 2301: 2291: 2285: 2244:or, equivalently, as the quotient of the 2230: 2162: 2123: 2119: 2118: 2115: 2085: 2081: 2080: 2077: 1988:Learn how and when to remove this message 1896:, angles measured from the center point. 1855: 1818: 1802: 1793: 1771: 1744: 1734: 1674: 1645: 1619: 1609: 1588: 1586: 1478: 1465: 1425: 1384: 1322: 1320: 1275: 1262: 1247: 1241: 1240: 1225: 1212: 1206: 1200: 1199: 1197: 1195: 1057: 1044: 1029: 1013: 1002: 989: 976: 963: 950: 938: 904: 891: 876: 870: 869: 854: 841: 835: 829: 828: 826: 824: 800: 795:for a torus radially symmetric about the 760: 755: 732: 709: 656: 589: 525: 466: 464: 303: 297: 268: 255: 249: 5265: 4538: 3330:letters (by permuting the coordinates). 2409:Intuitively speaking, this means that a 6068:Filippelli, Gianluigi (27 April 2012). 5747: 5486:The first 11 numbers of parts, for 0 ≤ 4286:isometric embedding of a flat torus in 3405:The simplest tiling of a flat torus is 3361:These orbifolds have found significant 3015:-torus is a free abelian group of rank 2833:by gluing the opposite faces together. 2067:The surface described above, given the 1311:of its torus are easily computed using 5210: 5206: 5173: 5169: 4205:is a rotation of 4-dimensional space 3117:whose generators are the duals of the 2980:in the usual way, one has the typical 2858:. This follows from the fact that the 191:A torus should not be confused with a 5838:from the original on 13 December 2014 4364:Conformal classification of flat tori 3990:/2 parameterize the unit 3-sphere as 3644:conditions are given up, see below). 3604:, which can also be described as the 3175:The Tonnetz is only truly a torus if 2851:. It is also an example of a compact 2523:-dimensional torus is the product of 2146:The torus can also be described as a 27:Doughnut-shaped surface of revolution 7: 5698:. Cambridge University Press, 2002. 4238:is a member of the Lie group SO(4). 2265:Turning a punctured torus inside-out 6323:Anders Sandberg (4 February 2014). 4766:that preserve the standard lattice 4398:may be turned into a compact space 91: 6290:Polydoes, doughnut-shaped polygons 6131:Enrico de Lazaro (18 April 2012). 6034:from the original on 25 July 2011. 5917:Journal of Applied Crystallography 5812:from the original on 29 April 2012 5806:"Equations for the Standard Torus" 5709:V. V. Nikulin, I. R. Shafarevich. 5190:can be embedded on the torus, and 3412:, constructed on the surface of a 2893:. Toroidal groups are examples of 2723:can be described as a quotient of 2690:. And similar to the 2-torus, the 1918:are more commonly used to discuss 25: 6112:from the original on 25 June 2012 5183:{\displaystyle {\mathsf {K_{7}}}} 4483:surface resembles the surface of 4241:It is known that there exists no 3200:-fold product of the circle, the 2023:. This can be viewed as lying in 440:: self-intersecting spindle torus 277:{\displaystyle S^{1}\times S^{1}} 6143:from the original on 1 June 2012 5970:"The Geometry of Musical Chords" 5968:Tymoczko, Dmitri (7 July 2006). 5887:Oxford English Dictionary Online 5519: 5002:{\displaystyle \mathbb {R} ^{n}} 4788:{\displaystyle \mathbb {Z} ^{n}} 4759:{\displaystyle \mathbb {R} ^{n}} 4648: 4553: 4542: 4345:{\displaystyle \mathbb {R} ^{3}} 4308:{\displaystyle \mathbb {R} ^{3}} 4227:{\displaystyle \mathbb {R} ^{4}} 3550:{\displaystyle \mathbb {Z} ^{2}} 3512:{\displaystyle \mathbb {Z} ^{2}} 3483:{\displaystyle \mathbb {R} ^{2}} 3446:{\displaystyle \mathbb {R} ^{2}} 3110:{\displaystyle \mathbb {Z} ^{n}} 3066:{\displaystyle \mathbb {T} ^{n}} 2973:{\displaystyle \mathbb {R} ^{n}} 2933:{\displaystyle \mathbb {Z} ^{n}} 2814:{\displaystyle \mathbb {Z} ^{n}} 2778:{\displaystyle \mathbb {R} ^{n}} 2745:{\displaystyle \mathbb {R} ^{n}} 2716:{\displaystyle \mathbb {T} ^{n}} 2683:{\displaystyle \mathbb {T} ^{2}} 2511:-torus", the other referring to 2476:A stereographic projection of a 2132:{\displaystyle \mathbb {R} ^{3}} 2094:{\displaystyle \mathbb {R} ^{3}} 1934: 1295:(and, hence, homeomorphic) to a 424: 401: 378: 197:, which is formed by rotating a 145:to the circle, the surface is a 6189:"Flat tori finally visualized!" 6045:Phillips, Tony (October 2006). 5908:De Graef, Marc (7 March 2024). 5733:"Tore (notion géométrique)" at 4525:for surfaces states that every 2433:since the fundamental group is 141:. If the axis of revolution is 5808:. Geom.uiuc.edu. 6 July 1995. 5467: 5429: 5217: 5200: 5117: 5114: 5099: 5083: 5080: 5065: 5056: 5053: 5038: 5022: 4943: 4929: 4917: 4902: 4890: 4887: 4881: 4868: 4856: 4841: 4724: 4710: 4069: 4045: 3927: 3900: 3879: 3864: 3843: 3840: 3834: 3816: 3747: 3687: 3681: 3657: 3250: 3234: 2374: 2359: 2343: 2328: 2312: 2297: 2224: 2206: 2200: 2182: 2176: 2164: 1852: 1839: 1836: 1824: 1707: 1695: 1692: 1680: 925:Algebraically eliminating the 685: 670: 613: 601: 580: 559: 549: 537: 516: 495: 485: 473: 1: 6051:American Mathematical Society 5576:Irrational winding of a torus 5331:(> 0) planes into at most 5156:of at most seven. (Since the 3269:. The configuration space of 3077:) can be identified with the 6284:"Relational Perspective Map" 5490:≤ 10 (including the case of 4540: 4518:are also occasionally used. 3363:applications to music theory 2825:-torus is obtained from the 2110:the topological torus into 2108:stereographically projecting 1307:of this solid torus and the 6047:"Take on Math in the Media" 5319:is 1 (one dimension). 4319:In April 2012, an explicit 4020:. One example is the torus 3775:to a regular torus but not 1920:magnetic confinement fusion 1882:spherical coordinate system 747:is the radius of the tube. 394:: ring torus or anchor ring 6650: 5591:Loewner's torus inequality 5259: 4571: 4443: 3798:) into Euclidean 3-space. 3608:under the identifications 3461:is a discrete subgroup of 3123: 2940:, which are classified by 2154:under the identifications 1907:is moved to the center of 1135:and its outer shell is an 651:using angular coordinates 36: 29: 6214:Hoang, Lê Nguyên (2016). 5889:. Oxford University Press 5774:10.1007/978-3-642-34364-3 5275:model of de Bruijn torus 4506:-holed tori (or, rarely, 4380:to one that has constant 3337:= 2, the quotient is the 3187:segment of the left edge. 3143:quotient of the 2-torus, 2273:of the torus is just the 1313:Pappus's centroid theorem 173:, as in a square toroid. 106:generated by revolving a 5651:Torus-based cryptography 4635:is the number of holes. 3391:stereographic projection 3179:is assumed, so that the 1943:This section includes a 30:Not to be confused with 6500:Sphere with three holes 6087:10.1073/pnas.1118478109 6009:10.1126/science.1126287 4964:Eilenberg–MacLane space 4642:of toroidal polyhedra. 4510:-fold tori). The terms 4424:has area equal to π/3. 2139:from the north pole of 2029:and is a subset of the 1972:more precise citations. 372:vertical cross-sections 161:self-intersecting torus 112:three-dimensional space 5474: 5285: 5252: 5230: 5184: 5127: 5003: 4962:Since the torus is an 4953: 4789: 4760: 4731: 4594: 4523:classification theorem 4378:conformally equivalent 4374:Uniformization theorem 4346: 4316: 4309: 4280: 4228: 4180: 3937: 3754: 3598: 3551: 3513: 3484: 3447: 3417: 3398: 3382: 3316: 3263: 3189: 3177:enharmonic equivalence 3159: 3111: 3067: 3025:. It follows that the 2974: 2934: 2877:one can always find a 2815: 2779: 2746: 2717: 2684: 2655: 2608: 2485: 2400: 2266: 2235: 2133: 2095: 1872: 1495: 1285: 1075: 917: 809: 772: 741: 718: 695: 643: 452: 313: 278: 79: 71: 66:into a double-covered 55: 43:Torus (disambiguation) 41:. For other uses, see 6418:Real projective plane 6403:Pretzel (genus 3) ... 5948:mathworld.wolfram.com 5711:Geometries and Groups 5646:Toroidal and poloidal 5606:Real projective plane 5475: 5271: 5250: 5231: 5185: 5150:embedded on the torus 5128: 5004: 4954: 4790: 4761: 4732: 4581: 4572:Further information: 4347: 4310: 4281: 4279:{\displaystyle C^{1}} 4259: 4229: 4181: 3938: 3755: 3599: 3552: 3514: 3485: 3448: 3404: 3388: 3380: 3353:; equivalently, as a 3317: 3264: 3165: 3138: 3112: 3068: 2975: 2935: 2816: 2780: 2747: 2718: 2685: 2656: 2609: 2475: 2401: 2264: 2236: 2134: 2096: 1916:toroidal and poloidal 1873: 1496: 1286: 1076: 918: 810: 793:Cartesian coordinates 773: 742: 719: 696: 644: 450: 314: 312:{\displaystyle S^{1}} 279: 104:surface of revolution 77: 61: 53: 6573:Euler characteristic 5581:Joint European Torus 5338: 5194: 5163: 5016: 4984: 4978:short exact sequence 4825: 4770: 4741: 4701: 4602:Euler characteristic 4327: 4290: 4263: 4234:, or in other words 4209: 4031: 3813: 3654: 3562: 3532: 3494: 3465: 3428: 3347:equilateral triangle 3280: 3216: 3092: 3048: 3033:-torus is 0 for all 3027:Euler characteristic 2955: 2915: 2881:; that is, a closed 2796: 2760: 2727: 2698: 2665: 2621: 2534: 2461:of the four points. 2284: 2161: 2114: 2076: 1585: 1319: 1194: 937: 823: 799: 754: 731: 708: 655: 463: 296: 248: 6307:(27 January 2014). 6269:Creation of a torus 5991:2006Sci...313...72T 5942:Weisstein, Eric W. 4695:mapping class group 4687:homeomorphism group 4584:toroidal polyhedron 4574:Toroidal polyhedron 4315:, with corrugations 4247:Nash-Kuiper theorem 3521:Riemannian manifold 3206:configuration space 3131:Configuration space 3126:Quasitoric manifold 3121:nontrivial cycles. 2496:, often called the 2492:n-dimensional torus 2451:conformal structure 2447:ramification points 2250:fundamental polygon 1301:Euclidean open disk 771:{\displaystyle R/r} 157:self-crossing torus 135:torus of revolution 6400:Number 8 (genus 2) 6242:Weisstein, Eric W. 6057:on 5 October 2008. 5859:Weisstein, Eric W. 5713:. Springer, 1987. 5695:Algebraic Topology 5666:Villarceau circles 5621:Surface (topology) 5551:Annulus (geometry) 5527:Mathematics portal 5470: 5427: 5408: 5373: 5313:De Bruijn sequence 5286: 5253: 5238:four color theorem 5226: 5180: 5123: 4999: 4949: 4785: 4756: 4727: 4691:geometric topology 4660:. You can help by 4595: 4568:Toroidal polyhedra 4495:handles attached. 4466:surfaces. A genus 4413:geodesic triangles 4382:Gaussian curvature 4342: 4317: 4305: 4276: 4224: 4176: 3933: 3750: 3641:Gaussian curvature 3594: 3547: 3509: 3480: 3443: 3418: 3399: 3383: 3312: 3259: 3190: 3160: 3107: 3063: 2997:free abelian group 2982:toral automorphism 2970: 2930: 2871:compact Lie groups 2811: 2775: 2742: 2713: 2680: 2651: 2604: 2600: 2593: 2527:circles. That is: 2515:holes or of genus 2486: 2468:-dimensional torus 2455:Weierstrass points 2396: 2267: 2231: 2129: 2091: 1945:list of references 1868: 1866: 1812: 1491: 1489: 1303:and a circle. The 1281: 1253: 1071: 913: 882: 805: 768: 737: 714: 691: 639: 637: 453: 309: 274: 232:, a ring torus is 137:, also known as a 131:axis of revolution 80: 72: 56: 6621: 6620: 6617: 6616: 6451: 6450: 6080:(19): 7218–7223. 5783:978-3-642-34363-6 5727:978-3-540-15281-1 5687:978-970-10-6596-9 5426: 4808:fundamental group 4678: 4677: 4565: 4564: 4534:projective planes 4454:In the theory of 4166: 4131: 4124: 3188: 2989:fundamental group 2984:on the quotient. 2945:integral matrices 2554: 2552: 2441:Two-sheeted cover 2271:fundamental group 2069:relative topology 1998: 1997: 1990: 1811: 1787: 1760: 1661: 1635: 1291:of this torus is 1231: 860: 808:{\displaystyle z} 740:{\displaystyle r} 717:{\displaystyle R} 370:Bottom-halves and 238:Cartesian product 213:, non-inflatable 16:(Redirected from 6641: 6536:Triangulatedness 6516: 6379: 6375:Without boundary 6363: 6356: 6349: 6340: 6335: 6333: 6331: 6319: 6313: 6256: 6255: 6254: 6237: 6231: 6230: 6228: 6226: 6211: 6205: 6204: 6202: 6200: 6185: 6179: 6178: 6176: 6174: 6165:. Archived from 6159: 6153: 6152: 6150: 6148: 6128: 6122: 6121: 6119: 6117: 6099: 6089: 6065: 6059: 6058: 6053:. Archived from 6042: 6036: 6035: 6033: 6002: 5974: 5965: 5959: 5958: 5956: 5954: 5939: 5933: 5927: 5921: 5920: 5914: 5905: 5899: 5898: 5896: 5894: 5879: 5873: 5872: 5871: 5854: 5848: 5847: 5845: 5843: 5834:. Spatial Corp. 5828: 5822: 5821: 5819: 5817: 5802: 5796: 5795: 5752: 5529: 5524: 5523: 5503: 5479: 5477: 5476: 5471: 5457: 5456: 5441: 5440: 5428: 5419: 5413: 5412: 5378: 5377: 5282: 5270: 5235: 5233: 5232: 5227: 5216: 5215: 5214: 5213: 5189: 5187: 5186: 5181: 5179: 5178: 5177: 5176: 5154:chromatic number 5140:Coloring a torus 5132: 5130: 5129: 5124: 5113: 5112: 5107: 5095: 5094: 5079: 5078: 5073: 5052: 5051: 5046: 5034: 5033: 5008: 5006: 5005: 5000: 4998: 4997: 4992: 4958: 4956: 4955: 4950: 4942: 4916: 4915: 4910: 4880: 4879: 4855: 4854: 4849: 4837: 4836: 4812:cohomology group 4798:At the level of 4794: 4792: 4791: 4786: 4784: 4783: 4778: 4765: 4763: 4762: 4757: 4755: 4754: 4749: 4736: 4734: 4733: 4728: 4723: 4673: 4670: 4652: 4645: 4589: 4557: 4546: 4539: 4417:hyperbolic plane 4370:Riemann surfaces 4368:In the study of 4351: 4349: 4348: 4343: 4341: 4340: 4335: 4314: 4312: 4311: 4306: 4304: 4303: 4298: 4285: 4283: 4282: 4277: 4275: 4274: 4233: 4231: 4230: 4225: 4223: 4222: 4217: 4185: 4183: 4182: 4177: 4172: 4168: 4167: 4159: 4154: 4153: 4141: 4140: 4129: 4125: 4117: 4112: 4111: 4099: 4098: 4086: 4085: 4080: 4011: 4009: 3992:Hopf coordinates 3989: 3973: 3942: 3940: 3939: 3934: 3797: 3779:. It can not be 3759: 3757: 3756: 3751: 3635: 3603: 3601: 3600: 3595: 3593: 3592: 3587: 3581: 3576: 3575: 3570: 3557: 3556: 3554: 3553: 3548: 3546: 3545: 3540: 3518: 3516: 3515: 3510: 3508: 3507: 3502: 3489: 3487: 3486: 3481: 3479: 3478: 3473: 3452: 3450: 3449: 3444: 3442: 3441: 3436: 3355:triangular prism 3321: 3319: 3318: 3313: 3311: 3310: 3305: 3299: 3294: 3293: 3288: 3268: 3266: 3265: 3260: 3258: 3257: 3248: 3247: 3242: 3230: 3229: 3224: 3186: 3182: 3174: 3116: 3114: 3113: 3108: 3106: 3105: 3100: 3079:exterior algebra 3072: 3070: 3069: 3064: 3062: 3061: 3056: 2979: 2977: 2976: 2971: 2969: 2968: 2963: 2939: 2937: 2936: 2931: 2929: 2928: 2923: 2820: 2818: 2817: 2812: 2810: 2809: 2804: 2784: 2782: 2781: 2776: 2774: 2773: 2768: 2751: 2749: 2748: 2743: 2741: 2740: 2735: 2722: 2720: 2719: 2714: 2712: 2711: 2706: 2689: 2687: 2686: 2681: 2679: 2678: 2673: 2660: 2658: 2657: 2652: 2650: 2649: 2644: 2635: 2634: 2629: 2613: 2611: 2610: 2605: 2599: 2594: 2589: 2588: 2587: 2582: 2567: 2566: 2561: 2548: 2547: 2542: 2494: 2493: 2431:Hurewicz theorem 2425:of the torus is 2405: 2403: 2402: 2397: 2392: 2384: 2373: 2372: 2367: 2358: 2357: 2342: 2341: 2336: 2327: 2326: 2311: 2310: 2305: 2296: 2295: 2240: 2238: 2237: 2232: 2138: 2136: 2135: 2130: 2128: 2127: 2122: 2100: 2098: 2097: 2092: 2090: 2089: 2084: 1993: 1986: 1982: 1979: 1973: 1968:this section by 1959:inline citations 1938: 1937: 1930: 1910: 1906: 1902: 1895: 1891: 1887: 1877: 1875: 1874: 1869: 1867: 1860: 1859: 1823: 1822: 1813: 1804: 1798: 1797: 1792: 1788: 1783: 1772: 1765: 1761: 1756: 1745: 1739: 1738: 1679: 1678: 1666: 1662: 1657: 1646: 1640: 1636: 1631: 1620: 1614: 1613: 1580: 1579: 1577: 1576: 1573: 1570: 1552: 1551: 1549: 1548: 1545: 1542: 1524: 1520: 1513: 1509: 1500: 1498: 1497: 1492: 1490: 1483: 1482: 1470: 1469: 1454: 1450: 1435: 1431: 1430: 1429: 1389: 1388: 1373: 1369: 1354: 1350: 1290: 1288: 1287: 1282: 1280: 1279: 1267: 1266: 1254: 1252: 1251: 1246: 1245: 1232: 1230: 1229: 1217: 1216: 1207: 1205: 1204: 1186: 1172: 1166: 1156: 1150: 1128: 1116: 1104: 1090: 1086: 1080: 1078: 1077: 1072: 1067: 1063: 1062: 1061: 1049: 1048: 1034: 1033: 1018: 1017: 1012: 1008: 1007: 1006: 994: 993: 981: 980: 968: 967: 955: 954: 931:quartic equation 922: 920: 919: 914: 909: 908: 896: 895: 883: 881: 880: 875: 874: 861: 859: 858: 846: 845: 836: 834: 833: 814: 812: 811: 806: 777: 775: 774: 769: 764: 746: 744: 743: 738: 723: 721: 720: 715: 700: 698: 697: 692: 648: 646: 645: 640: 638: 593: 529: 439: 428: 416: 405: 393: 382: 330:In the field of 318: 316: 315: 310: 308: 307: 283: 281: 280: 275: 273: 272: 260: 259: 93: 21: 6649: 6648: 6644: 6643: 6642: 6640: 6639: 6638: 6624: 6623: 6622: 6613: 6577: 6554:Characteristics 6549: 6511: 6505: 6447: 6406: 6370: 6367: 6329: 6327: 6322: 6311: 6305:Séquin, Carlo H 6303: 6300:Wayback Machine 6265: 6260: 6259: 6245:"Torus Cutting" 6240: 6239: 6238: 6234: 6224: 6222: 6213: 6212: 6208: 6198: 6196: 6195:on 18 June 2012 6187: 6186: 6182: 6172: 6170: 6161: 6160: 6156: 6146: 6144: 6130: 6129: 6125: 6115: 6113: 6067: 6066: 6062: 6044: 6043: 6039: 6031: 6000:10.1.1.215.7449 5985:(5783): 72–74. 5972: 5967: 5966: 5962: 5952: 5950: 5941: 5940: 5936: 5928: 5924: 5912: 5907: 5906: 5902: 5892: 5890: 5881: 5880: 5876: 5857: 5856: 5855: 5851: 5841: 5839: 5830: 5829: 5825: 5815: 5813: 5804: 5803: 5799: 5784: 5754: 5753: 5749: 5744: 5692:Allen Hatcher. 5675: 5670: 5541:Algebraic torus 5525: 5518: 5515: 5499: 5448: 5432: 5407: 5406: 5394: 5393: 5383: 5372: 5371: 5359: 5358: 5342: 5336: 5335: 5325: 5323:Cutting a torus 5294:de Bruijn torus 5292:mathematics, a 5281: 5277: 5266: 5264: 5262:de Bruijn torus 5258: 5256:de Bruijn torus 5205: 5192: 5191: 5168: 5161: 5160: 5142: 5102: 5086: 5068: 5041: 5025: 5014: 5013: 4987: 4982: 4981: 4905: 4871: 4844: 4828: 4823: 4822: 4773: 4768: 4767: 4744: 4739: 4738: 4699: 4698: 4683: 4674: 4668: 4665: 4658:needs expansion 4587: 4576: 4570: 4558: 4547: 4470:surface is the 4452: 4442: 4366: 4358:surface normals 4330: 4325: 4324: 4293: 4288: 4287: 4266: 4261: 4260: 4212: 4207: 4206: 4145: 4132: 4103: 4090: 4075: 4044: 4040: 4029: 4028: 4007: 4002: 3987: 3955: 3811: 3810: 3788: 3652: 3651: 3609: 3606:Cartesian plane 3582: 3565: 3560: 3559: 3535: 3530: 3529: 3524: 3497: 3492: 3491: 3468: 3463: 3462: 3431: 3426: 3425: 3410: 3375: 3324:symmetric group 3300: 3283: 3278: 3277: 3249: 3237: 3219: 3214: 3213: 3184: 3180: 3173: 3154:, which is the 3153: 3133: 3128: 3095: 3090: 3089: 3051: 3046: 3045: 3039:cohomology ring 2958: 2953: 2952: 2918: 2913: 2912: 2864:complex numbers 2799: 2794: 2793: 2789:of the integer 2763: 2758: 2757: 2730: 2725: 2724: 2701: 2696: 2695: 2668: 2663: 2662: 2639: 2624: 2619: 2618: 2577: 2556: 2555: 2537: 2532: 2531: 2491: 2490: 2470: 2443: 2362: 2349: 2331: 2318: 2300: 2287: 2282: 2281: 2159: 2158: 2152:Cartesian plane 2117: 2112: 2111: 2079: 2074: 2073: 2007:defined as the 2003:, a torus is a 1994: 1983: 1977: 1974: 1963: 1949:related reading 1939: 1935: 1928: 1914:In modern use, 1908: 1904: 1900: 1893: 1889: 1885: 1865: 1864: 1851: 1814: 1773: 1767: 1766: 1746: 1740: 1730: 1720: 1714: 1713: 1670: 1647: 1641: 1621: 1615: 1605: 1595: 1583: 1582: 1574: 1571: 1562: 1561: 1559: 1554: 1546: 1543: 1534: 1533: 1531: 1526: 1522: 1518: 1511: 1504: 1488: 1487: 1474: 1461: 1440: 1436: 1421: 1417: 1413: 1406: 1400: 1399: 1380: 1359: 1355: 1340: 1336: 1329: 1317: 1316: 1271: 1258: 1239: 1221: 1208: 1192: 1191: 1178: 1168: 1161: 1152: 1145: 1120: 1108: 1096: 1088: 1084: 1053: 1040: 1039: 1035: 1025: 998: 985: 972: 959: 946: 945: 941: 940: 935: 934: 900: 887: 868: 850: 837: 821: 820: 797: 796: 752: 751: 729: 728: 706: 705: 653: 652: 636: 635: 616: 595: 594: 552: 531: 530: 488: 461: 460: 455:A torus can be 445: 444: 443: 442: 441: 431: 429: 420: 419: 418: 408: 406: 397: 396: 395: 385: 383: 374: 373: 371: 365: 352: 323:, a surface in 299: 294: 293: 286:Euclidean space 264: 251: 246: 245: 46: 35: 28: 23: 22: 15: 12: 11: 5: 6647: 6645: 6637: 6636: 6626: 6625: 6619: 6618: 6615: 6614: 6612: 6611: 6606: 6600: 6594: 6591: 6585: 6583: 6579: 6578: 6576: 6575: 6570: 6565: 6557: 6555: 6551: 6550: 6548: 6547: 6542: 6533: 6528: 6522: 6520: 6513: 6507: 6506: 6504: 6503: 6497: 6496: 6495: 6485: 6484: 6483: 6478: 6470: 6469: 6468: 6459: 6457: 6453: 6452: 6449: 6448: 6446: 6445: 6442:Dyck's surface 6439: 6433: 6432: 6431: 6426: 6414: 6412: 6411:Non-orientable 6408: 6407: 6405: 6404: 6401: 6398: 6392: 6385: 6383: 6376: 6372: 6371: 6368: 6366: 6365: 6358: 6351: 6343: 6337: 6336: 6320: 6292: 6287: 6281: 6275: 6264: 6263:External links 6261: 6258: 6257: 6232: 6206: 6180: 6169:on 5 July 2012 6154: 6123: 6060: 6037: 5960: 5934: 5922: 5900: 5874: 5849: 5823: 5797: 5782: 5746: 5745: 5743: 5740: 5739: 5738: 5730: 5707: 5690: 5674: 5671: 5669: 5668: 5663: 5658: 5653: 5648: 5643: 5638: 5633: 5628: 5623: 5618: 5616:Spiric section 5613: 5608: 5603: 5601:Period lattice 5598: 5593: 5588: 5583: 5578: 5573: 5571:Elliptic curve 5568: 5563: 5558: 5556:Clifford torus 5553: 5548: 5546:Angenent torus 5543: 5538: 5532: 5531: 5530: 5514: 5511: 5510: 5509: 5481: 5480: 5469: 5466: 5463: 5460: 5455: 5451: 5447: 5444: 5439: 5435: 5431: 5425: 5422: 5416: 5411: 5405: 5402: 5399: 5396: 5395: 5392: 5389: 5388: 5386: 5381: 5376: 5370: 5367: 5364: 5361: 5360: 5357: 5354: 5351: 5348: 5347: 5345: 5324: 5321: 5279: 5260:Main article: 5257: 5254: 5225: 5222: 5219: 5212: 5208: 5202: 5199: 5175: 5171: 5158:complete graph 5146:Heawood number 5141: 5138: 5134: 5133: 5122: 5119: 5116: 5111: 5106: 5101: 5098: 5093: 5089: 5085: 5082: 5077: 5072: 5067: 5064: 5061: 5058: 5055: 5050: 5045: 5040: 5037: 5032: 5028: 5024: 5021: 4996: 4991: 4960: 4959: 4948: 4945: 4941: 4937: 4934: 4931: 4928: 4925: 4922: 4919: 4914: 4909: 4904: 4901: 4898: 4895: 4892: 4889: 4886: 4883: 4878: 4874: 4870: 4867: 4864: 4861: 4858: 4853: 4848: 4843: 4840: 4835: 4831: 4814:generates the 4782: 4777: 4753: 4748: 4726: 4722: 4718: 4715: 4712: 4709: 4706: 4682: 4679: 4676: 4675: 4655: 4653: 4569: 4566: 4563: 4562: 4551: 4444:Main article: 4441: 4434: 4365: 4362: 4339: 4334: 4302: 4297: 4273: 4269: 4221: 4216: 4189:Other tori in 4187: 4186: 4175: 4171: 4165: 4162: 4157: 4152: 4148: 4144: 4139: 4135: 4128: 4123: 4120: 4115: 4110: 4106: 4102: 4097: 4093: 4089: 4084: 4079: 4074: 4071: 4068: 4065: 4062: 4059: 4056: 4053: 4050: 4047: 4043: 4039: 4036: 3944: 3943: 3932: 3929: 3926: 3923: 3920: 3917: 3914: 3911: 3908: 3905: 3902: 3899: 3896: 3893: 3890: 3887: 3884: 3881: 3878: 3875: 3872: 3869: 3866: 3863: 3860: 3857: 3854: 3851: 3848: 3845: 3842: 3839: 3836: 3833: 3830: 3827: 3824: 3821: 3818: 3761: 3760: 3749: 3746: 3743: 3740: 3737: 3734: 3731: 3728: 3725: 3722: 3719: 3716: 3713: 3710: 3707: 3704: 3701: 3698: 3695: 3692: 3689: 3686: 3683: 3680: 3677: 3674: 3671: 3668: 3665: 3662: 3659: 3591: 3586: 3580: 3574: 3569: 3544: 3539: 3506: 3501: 3490:isomorphic to 3477: 3472: 3440: 3435: 3408: 3374: 3371: 3367:musical triads 3309: 3304: 3298: 3292: 3287: 3256: 3252: 3246: 3241: 3236: 3233: 3228: 3223: 3204:-torus is the 3196:-torus is the 3151: 3132: 3129: 3104: 3099: 3060: 3055: 3009:homology group 2967: 2962: 2927: 2922: 2808: 2803: 2772: 2767: 2739: 2734: 2710: 2705: 2677: 2672: 2648: 2643: 2638: 2633: 2628: 2615: 2614: 2603: 2598: 2592: 2586: 2581: 2576: 2573: 2570: 2565: 2560: 2551: 2546: 2541: 2506: 2502: 2495: 2478:Clifford torus 2469: 2463: 2442: 2439: 2423:homology group 2407: 2406: 2395: 2391: 2387: 2383: 2379: 2376: 2371: 2366: 2361: 2356: 2352: 2348: 2345: 2340: 2335: 2330: 2325: 2321: 2317: 2314: 2309: 2304: 2299: 2294: 2290: 2275:direct product 2242: 2241: 2229: 2226: 2223: 2220: 2217: 2214: 2211: 2208: 2205: 2202: 2199: 2196: 2193: 2190: 2187: 2184: 2181: 2178: 2175: 2172: 2169: 2166: 2126: 2121: 2088: 2083: 2038:Clifford torus 2005:closed surface 1996: 1995: 1953:external links 1942: 1940: 1933: 1927: 1924: 1863: 1858: 1854: 1850: 1847: 1844: 1841: 1838: 1835: 1832: 1829: 1826: 1821: 1817: 1810: 1807: 1801: 1796: 1791: 1786: 1782: 1779: 1776: 1770: 1764: 1759: 1755: 1752: 1749: 1743: 1737: 1733: 1729: 1726: 1723: 1721: 1719: 1716: 1715: 1712: 1709: 1706: 1703: 1700: 1697: 1694: 1691: 1688: 1685: 1682: 1677: 1673: 1669: 1665: 1660: 1656: 1653: 1650: 1644: 1639: 1634: 1630: 1627: 1624: 1618: 1612: 1608: 1604: 1601: 1598: 1596: 1594: 1591: 1590: 1486: 1481: 1477: 1473: 1468: 1464: 1460: 1457: 1453: 1449: 1446: 1443: 1439: 1434: 1428: 1424: 1420: 1416: 1412: 1409: 1407: 1405: 1402: 1401: 1398: 1395: 1392: 1387: 1383: 1379: 1376: 1372: 1368: 1365: 1362: 1358: 1353: 1349: 1346: 1343: 1339: 1335: 1332: 1330: 1328: 1325: 1324: 1278: 1274: 1270: 1265: 1261: 1257: 1250: 1244: 1238: 1235: 1228: 1224: 1220: 1215: 1211: 1203: 1175: 1174: 1158: 1142: 1118: 1106: 1070: 1066: 1060: 1056: 1052: 1047: 1043: 1038: 1032: 1028: 1024: 1021: 1016: 1011: 1005: 1001: 997: 992: 988: 984: 979: 975: 971: 966: 962: 958: 953: 949: 944: 912: 907: 903: 899: 894: 890: 886: 879: 873: 867: 864: 857: 853: 849: 844: 840: 832: 804: 778:is called the 767: 763: 759: 736: 713: 690: 687: 684: 681: 678: 675: 672: 669: 666: 663: 660: 634: 631: 628: 625: 622: 619: 617: 615: 612: 609: 606: 603: 600: 597: 596: 592: 588: 585: 582: 579: 576: 573: 570: 567: 564: 561: 558: 555: 553: 551: 548: 545: 542: 539: 536: 533: 532: 528: 524: 521: 518: 515: 512: 509: 506: 503: 500: 497: 494: 491: 489: 487: 484: 481: 478: 475: 472: 469: 468: 430: 423: 422: 421: 407: 400: 399: 398: 384: 377: 376: 375: 369: 368: 367: 366: 364: 361: 351: 348: 321:Clifford torus 306: 302: 271: 267: 263: 258: 254: 186:ringette rings 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 6646: 6635: 6632: 6631: 6629: 6610: 6607: 6605: 6601: 6599: 6595: 6593:Making a hole 6592: 6590: 6589:Connected sum 6587: 6586: 6584: 6580: 6574: 6571: 6569: 6566: 6563: 6559: 6558: 6556: 6552: 6546: 6545:Orientability 6543: 6541: 6537: 6534: 6532: 6529: 6527: 6526:Connectedness 6524: 6523: 6521: 6517: 6514: 6508: 6501: 6498: 6494: 6491: 6490: 6489: 6486: 6482: 6479: 6477: 6474: 6473: 6471: 6466: 6465: 6464: 6461: 6460: 6458: 6456:With boundary 6454: 6444:(genus 3) ... 6443: 6440: 6437: 6434: 6430: 6429:Roman surface 6427: 6425: 6424:Boy's surface 6421: 6420: 6419: 6416: 6415: 6413: 6409: 6402: 6399: 6396: 6393: 6390: 6387: 6386: 6384: 6380: 6377: 6373: 6364: 6359: 6357: 6352: 6350: 6345: 6344: 6341: 6326: 6325:"Torus Earth" 6321: 6317: 6310: 6306: 6301: 6297: 6293: 6291: 6288: 6285: 6282: 6279: 6276: 6274: 6270: 6267: 6266: 6262: 6252: 6251: 6246: 6243: 6236: 6233: 6221: 6217: 6210: 6207: 6194: 6190: 6184: 6181: 6168: 6164: 6158: 6155: 6142: 6138: 6134: 6127: 6124: 6111: 6107: 6103: 6098: 6093: 6088: 6083: 6079: 6075: 6071: 6064: 6061: 6056: 6052: 6048: 6041: 6038: 6030: 6026: 6022: 6018: 6014: 6010: 6006: 6001: 5996: 5992: 5988: 5984: 5980: 5979: 5971: 5964: 5961: 5949: 5945: 5938: 5935: 5932: 5926: 5923: 5918: 5911: 5904: 5901: 5888: 5884: 5878: 5875: 5869: 5868: 5863: 5860: 5853: 5850: 5837: 5833: 5827: 5824: 5811: 5807: 5801: 5798: 5793: 5789: 5785: 5779: 5775: 5771: 5767: 5766: 5761: 5757: 5756:Gallier, Jean 5751: 5748: 5741: 5737: 5736: 5731: 5728: 5724: 5720: 5719:3-540-15281-4 5716: 5712: 5708: 5705: 5704:0-521-79540-0 5701: 5697: 5696: 5691: 5688: 5684: 5680: 5677: 5676: 5672: 5667: 5664: 5662: 5661:Umbilic torus 5659: 5657: 5654: 5652: 5649: 5647: 5644: 5642: 5639: 5637: 5636:Toric variety 5634: 5632: 5631:Toric section 5629: 5627: 5624: 5622: 5619: 5617: 5614: 5612: 5609: 5607: 5604: 5602: 5599: 5597: 5596:Maximal torus 5594: 5592: 5589: 5587: 5584: 5582: 5579: 5577: 5574: 5572: 5569: 5567: 5566:Dupin cyclide 5564: 5562: 5561:Complex torus 5559: 5557: 5554: 5552: 5549: 5547: 5544: 5542: 5539: 5537: 5534: 5533: 5528: 5522: 5517: 5512: 5507: 5502: 5497: 5496: 5495: 5493: 5489: 5484: 5464: 5461: 5458: 5453: 5449: 5445: 5442: 5437: 5433: 5423: 5420: 5414: 5409: 5403: 5400: 5397: 5390: 5384: 5379: 5374: 5368: 5365: 5362: 5355: 5352: 5349: 5343: 5334: 5333: 5332: 5330: 5322: 5320: 5318: 5314: 5310: 5307: 5303: 5299: 5295: 5291: 5290:combinatorial 5283: 5274: 5269: 5263: 5255: 5249: 5245: 5243: 5239: 5223: 5220: 5197: 5159: 5155: 5151: 5147: 5139: 5137: 5120: 5109: 5096: 5091: 5087: 5075: 5062: 5059: 5048: 5035: 5030: 5026: 5019: 5012: 5011: 5010: 4994: 4979: 4974: 4972: 4968: 4965: 4946: 4935: 4932: 4926: 4923: 4920: 4912: 4899: 4896: 4893: 4884: 4876: 4872: 4865: 4862: 4859: 4851: 4838: 4833: 4829: 4821: 4820: 4819: 4817: 4813: 4809: 4805: 4801: 4796: 4780: 4751: 4716: 4713: 4707: 4704: 4696: 4692: 4688: 4681:Automorphisms 4680: 4672: 4663: 4659: 4656:This section 4654: 4651: 4647: 4646: 4643: 4641: 4636: 4634: 4630: 4626: 4622: 4618: 4614: 4610: 4606: 4603: 4599: 4592: 4591:quadrilateral 4585: 4580: 4575: 4567: 4561: 4556: 4552: 4550: 4545: 4541: 4537: 4535: 4531: 4528: 4524: 4519: 4517: 4513: 4509: 4505: 4501: 4496: 4494: 4490: 4486: 4482: 4477: 4473: 4472:connected sum 4469: 4465: 4461: 4457: 4451: 4449: 4439: 4435: 4433: 4430: 4425: 4423: 4418: 4414: 4410: 4406: 4401: 4397: 4393: 4391: 4387: 4383: 4379: 4375: 4371: 4363: 4361: 4359: 4355: 4337: 4322: 4300: 4271: 4267: 4258: 4254: 4252: 4248: 4244: 4239: 4237: 4219: 4204: 4200: 4196: 4192: 4173: 4169: 4163: 4160: 4155: 4150: 4146: 4142: 4137: 4133: 4126: 4121: 4118: 4113: 4108: 4104: 4100: 4095: 4091: 4087: 4082: 4072: 4066: 4063: 4060: 4057: 4054: 4051: 4048: 4041: 4037: 4034: 4027: 4026: 4025: 4023: 4019: 4015: 4005: 4000: 3997: 3993: 3985: 3982:, and 0 < 3981: 3977: 3971: 3967: 3963: 3959: 3953: 3949: 3930: 3924: 3921: 3918: 3915: 3912: 3909: 3906: 3903: 3897: 3894: 3891: 3888: 3885: 3882: 3876: 3873: 3870: 3867: 3861: 3858: 3855: 3852: 3849: 3846: 3837: 3831: 3828: 3825: 3822: 3819: 3809: 3808: 3807: 3805: 3801: 3795: 3791: 3786: 3782: 3778: 3774: 3773:diffeomorphic 3770: 3766: 3744: 3741: 3738: 3735: 3732: 3729: 3726: 3723: 3720: 3717: 3714: 3711: 3708: 3705: 3702: 3699: 3696: 3693: 3690: 3684: 3678: 3675: 3672: 3669: 3666: 3663: 3660: 3650: 3649: 3648: 3645: 3642: 3637: 3633: 3629: 3625: 3621: 3617: 3613: 3607: 3589: 3578: 3572: 3542: 3527: 3522: 3504: 3475: 3460: 3456: 3438: 3423: 3415: 3411: 3403: 3396: 3392: 3387: 3379: 3372: 3370: 3368: 3364: 3359: 3356: 3352: 3348: 3344: 3340: 3336: 3331: 3329: 3325: 3307: 3296: 3290: 3276: 3272: 3254: 3244: 3231: 3226: 3211: 3207: 3203: 3199: 3195: 3178: 3171: 3170: 3164: 3157: 3150: 3146: 3142: 3137: 3130: 3127: 3122: 3120: 3102: 3088: 3084: 3080: 3076: 3058: 3043: 3040: 3036: 3032: 3028: 3024: 3021: 3018: 3014: 3010: 3006: 3002: 2998: 2994: 2990: 2985: 2983: 2965: 2950: 2946: 2943: 2925: 2910: 2906: 2905:Automorphisms 2902: 2900: 2896: 2892: 2888: 2884: 2880: 2879:maximal torus 2876: 2872: 2867: 2865: 2861: 2857: 2854: 2850: 2847: 2843: 2839: 2834: 2832: 2829:-dimensional 2828: 2824: 2806: 2792: 2788: 2770: 2755: 2737: 2708: 2693: 2675: 2646: 2636: 2631: 2601: 2596: 2590: 2584: 2574: 2571: 2568: 2563: 2549: 2544: 2530: 2529: 2528: 2526: 2522: 2518: 2514: 2510: 2504: 2500: 2497: 2489: 2483: 2479: 2474: 2467: 2464: 2462: 2460: 2456: 2452: 2448: 2440: 2438: 2436: 2432: 2428: 2424: 2419: 2415: 2412: 2393: 2385: 2377: 2369: 2354: 2350: 2346: 2338: 2323: 2319: 2315: 2307: 2292: 2288: 2280: 2279: 2278: 2276: 2272: 2263: 2259: 2257: 2254: 2251: 2247: 2227: 2221: 2218: 2215: 2212: 2209: 2203: 2197: 2194: 2191: 2188: 2185: 2179: 2173: 2170: 2167: 2157: 2156: 2155: 2153: 2149: 2144: 2142: 2124: 2109: 2105: 2101: 2086: 2070: 2065: 2063: 2059: 2055: 2051: 2047: 2043: 2039: 2035: 2032: 2028: 2027: 2022: 2019: ×  2018: 2014: 2010: 2006: 2002: 2001:Topologically 1992: 1989: 1981: 1978:November 2015 1971: 1967: 1961: 1960: 1954: 1950: 1946: 1941: 1932: 1931: 1925: 1923: 1921: 1917: 1912: 1897: 1883: 1878: 1861: 1856: 1848: 1845: 1842: 1833: 1830: 1827: 1819: 1815: 1808: 1805: 1799: 1794: 1789: 1784: 1780: 1777: 1774: 1768: 1762: 1757: 1753: 1750: 1747: 1741: 1735: 1731: 1727: 1724: 1722: 1717: 1710: 1704: 1701: 1698: 1689: 1686: 1683: 1675: 1671: 1667: 1663: 1658: 1654: 1651: 1648: 1642: 1637: 1632: 1628: 1625: 1622: 1616: 1610: 1606: 1602: 1599: 1597: 1592: 1569: 1565: 1557: 1541: 1537: 1529: 1515: 1508: 1501: 1484: 1479: 1475: 1471: 1466: 1462: 1458: 1455: 1451: 1447: 1444: 1441: 1437: 1432: 1426: 1422: 1418: 1414: 1410: 1408: 1403: 1396: 1393: 1390: 1385: 1381: 1377: 1374: 1370: 1366: 1363: 1360: 1356: 1351: 1347: 1344: 1341: 1337: 1333: 1331: 1326: 1314: 1310: 1306: 1302: 1298: 1294: 1293:diffeomorphic 1276: 1272: 1268: 1263: 1259: 1255: 1248: 1236: 1233: 1226: 1222: 1218: 1213: 1209: 1190: 1185: 1181: 1171: 1164: 1159: 1155: 1148: 1143: 1140: 1139: 1134: 1133: 1127: 1123: 1119: 1115: 1111: 1107: 1103: 1099: 1094: 1093: 1092: 1081: 1068: 1064: 1058: 1054: 1050: 1045: 1041: 1036: 1030: 1026: 1022: 1019: 1014: 1009: 1003: 999: 995: 990: 986: 982: 977: 973: 969: 964: 960: 956: 951: 947: 942: 932: 928: 923: 910: 905: 901: 897: 892: 888: 884: 877: 865: 862: 855: 851: 847: 842: 838: 818: 802: 794: 790: 785: 783: 782: 765: 761: 757: 748: 734: 727: 711: 704: 688: 682: 679: 676: 673: 667: 664: 661: 658: 649: 632: 629: 626: 623: 620: 618: 610: 607: 604: 598: 590: 586: 583: 577: 574: 571: 568: 565: 562: 556: 554: 546: 543: 540: 534: 526: 522: 519: 513: 510: 507: 504: 501: 498: 492: 490: 482: 479: 476: 470: 458: 449: 438: 434: 427: 415: 411: 404: 392: 388: 381: 362: 360: 358: 357: 349: 347: 345: 339: 337: 333: 328: 326: 322: 304: 300: 291: 287: 269: 265: 261: 256: 252: 243: 239: 235: 231: 226: 224: 220: 216: 212: 208: 204: 200: 196: 195: 189: 187: 183: 179: 174: 172: 171: 166: 162: 158: 154: 153: 152:spindle torus 148: 144: 140: 136: 132: 127: 125: 121: 117: 113: 109: 105: 101: 97: 89: 85: 76: 69: 65: 60: 52: 48: 44: 40: 33: 19: 6488:Möbius strip 6436:Klein bottle 6394: 6328:. Retrieved 6296:Ghostarchive 6294:Archived at 6273:cut-the-knot 6248: 6235: 6223:. Retrieved 6219: 6209: 6197:. Retrieved 6193:the original 6183: 6171:. Retrieved 6167:the original 6157: 6145:. Retrieved 6137:Sci-News.com 6136: 6126: 6114:. Retrieved 6077: 6073: 6063: 6055:the original 6040: 5982: 5976: 5963: 5951:. Retrieved 5947: 5937: 5925: 5916: 5903: 5891:. Retrieved 5886: 5877: 5865: 5852: 5840:. Retrieved 5826: 5814:. Retrieved 5800: 5764: 5750: 5734: 5710: 5694: 5678: 5586:Klein bottle 5491: 5487: 5485: 5482: 5328: 5326: 5316: 5305: 5301: 5293: 5287: 5276: 5144:The torus's 5143: 5135: 4975: 4970: 4966: 4961: 4797: 4684: 4666: 4662:adding to it 4657: 4637: 4632: 4628: 4624: 4620: 4616: 4612: 4608: 4604: 4596: 4520: 4516:triple torus 4512:double torus 4507: 4503: 4497: 4492: 4484: 4480: 4475: 4467: 4463: 4453: 4447: 4437: 4428: 4426: 4421: 4408: 4404: 4399: 4395: 4394: 4389: 4386:moduli space 4367: 4320: 4318: 4250: 4242: 4240: 4235: 4202: 4198: 4194: 4190: 4188: 4021: 4003: 3998: 3983: 3979: 3975: 3969: 3965: 3961: 3957: 3951: 3947: 3945: 3803: 3793: 3789: 3781:analytically 3768: 3764: 3762: 3646: 3638: 3631: 3627: 3623: 3619: 3615: 3611: 3525: 3458: 3454: 3419: 3394: 3360: 3342: 3339:Möbius strip 3334: 3332: 3327: 3270: 3209: 3201: 3197: 3193: 3191: 3167: 3156:Möbius strip 3148: 3144: 3118: 3082: 3074: 3041: 3034: 3030: 3022: 3016: 3012: 3004: 3000: 2995:-torus is a 2992: 2986: 2981: 2948: 2908: 2903: 2890: 2886: 2874: 2868: 2844:dimensional 2841: 2837: 2835: 2826: 2822: 2753: 2691: 2616: 2524: 2520: 2516: 2512: 2508: 2498: 2487: 2481: 2465: 2444: 2420: 2416: 2408: 2268: 2255: 2252: 2243: 2145: 2140: 2104:homeomorphic 2066: 2057: 2054:fiber bundle 2049: 2041: 2033: 2025: 2020: 2016: 1999: 1984: 1975: 1964:Please help 1956: 1913: 1898: 1879: 1567: 1563: 1555: 1539: 1535: 1527: 1516: 1506: 1502: 1309:surface area 1183: 1179: 1176: 1169: 1162: 1153: 1146: 1136: 1130: 1125: 1121: 1113: 1109: 1101: 1097: 1082: 924: 791:equation in 786: 781:aspect ratio 779: 749: 726:minor radius 725: 703:major radius 702: 650: 457:parametrized 454: 436: 432: 417:: horn torus 413: 409: 390: 386: 354: 353: 344:Klein bottle 340: 329: 234:homeomorphic 227: 206: 192: 190: 175: 168: 160: 156: 150: 146: 138: 134: 128: 123: 119: 99: 95: 87: 81: 47: 6531:Compactness 6316:Brady Haran 6220:Science4All 5842:16 November 5278:(16,32;3,3) 4560:genus three 4024:defined by 3414:duocylinder 2860:unit circle 2785:modulo the 2459:cross-ratio 2411:closed path 2246:unit square 2062:Hopf bundle 2040:. In fact, 1970:introducing 1510:and radius 927:square root 207:solid torus 194:solid torus 182:inner tubes 64:degenerates 39:Solid torus 6582:Operations 6564:components 6560:Number of 6540:smoothness 6519:Properties 6467:Semisphere 6382:Orientable 6278:"4D torus" 6225:1 November 5919:: 638–648. 5883:"poloidal" 5760:Xu, Dianna 5742:References 5656:Torus knot 5626:Toric lens 4816:cohomology 4669:April 2010 4640:immersions 4588:6 × 4 = 24 4500:two-sphere 3783:embedded ( 3395:flat torus 3373:Flat torus 3124:See also: 2942:invertible 2756:-torus is 2505:hypertorus 2427:isomorphic 2421:The first 2046:filled out 1581:), yields 1315:, giving: 750:The ratio 178:swim rings 147:horn torus 139:ring torus 18:Flat torus 6609:Immersion 6604:cross-cap 6602:Gluing a 6596:Gluing a 6493:Cross-cap 6438:(genus 2) 6422:genus 1; 6397:(genus 1) 6391:(genus 0) 6250:MathWorld 5995:CiteSeerX 5893:10 August 5867:MathWorld 5401:− 5366:− 5198:χ 5118:→ 5097:⁡ 5084:→ 5063:⁡ 5057:→ 5036:⁡ 5023:→ 4976:Thus the 4927:⁡ 4900:⁡ 4873:π 4866:⁡ 4839:⁡ 4818:algebra: 4708:⁡ 4598:Polyhedra 4549:genus two 4530:connected 4088:∣ 4073:∈ 4014:congruent 3964:) = (cos( 3922:⁡ 3907:⁡ 3895:⁡ 3871:⁡ 3859:⁡ 3787:of class 3777:isometric 3742:⁡ 3727:⁡ 3712:⁡ 3697:⁡ 3349:, with a 3271:unordered 3081:over the 2899:manifolds 2856:Lie group 2831:hypercube 2591:⏟ 2575:× 2572:⋯ 2569:× 2386:× 2378:≅ 2351:π 2347:× 2320:π 2289:π 2204:∼ 2180:∼ 1922:devices. 1846:− 1816:π 1778:− 1732:π 1702:− 1672:π 1652:− 1607:π 1463:π 1445:π 1419:π 1382:π 1364:π 1345:π 1234:− 996:− 863:− 683:π 668:∈ 665:φ 659:θ 633:θ 630:⁡ 611:φ 605:θ 591:φ 587:⁡ 578:θ 575:⁡ 547:φ 541:θ 527:φ 523:⁡ 514:θ 511:⁡ 483:φ 477:θ 350:Etymology 290:embedding 262:× 219:doughnuts 215:lifebuoys 6634:Surfaces 6628:Category 6562:boundary 6481:Cylinder 6298:and the 6141:Archived 6110:Archived 6106:22523238 6029:Archived 6017:16825563 5836:Archived 5810:Archived 5762:(2013). 5513:See also 5240:for the 4804:homology 4800:homotopy 4631:, where 4489:2-sphere 4456:surfaces 4201:, where 4018:boundary 4001:, where 3996:3-sphere 3802:it into 3457:, where 3422:quotient 3389:Seen in 3275:orbifold 3141:orbifold 2999:of rank 2947:of size 2883:subgroup 2849:manifold 2694:-torus, 2449:. Every 2148:quotient 2031:3-sphere 1926:Topology 1189:interior 929:gives a 789:implicit 363:Geometry 332:topology 230:topology 209:include 124:doughnut 116:coplanar 84:geometry 6512:notions 6510:Related 6476:Annulus 6472:Ribbon 6330:24 July 6312:(video) 6199:21 July 6173:21 July 6147:21 July 6116:21 July 6097:3358891 6025:2877171 5987:Bibcode 5978:Science 5953:27 July 5944:"Torus" 5862:"Torus" 5832:"Torus" 5816:21 July 5792:3026641 5536:3-torus 5504:in the 5501:A003600 4627:= 2 − 2 4527:compact 4450:surface 4440:surface 4415:in the 4354:fractal 3968:), sin( 3800:Mapping 3393:, a 4D 3192:As the 3185:(G♭-B♭) 3181:(F♯-A♯) 3169:Tonnetz 3073:,  3029:of the 2895:protori 2853:abelian 2846:compact 2791:lattice 2435:abelian 2150:of the 2013:circles 2011:of two 2009:product 1966:improve 1578:⁠ 1560:⁠ 1550:⁠ 1532:⁠ 1297:product 325:4-space 242:circles 240:of two 236:to the 217:, ring 211:O-rings 143:tangent 129:If the 102:) is a 100:toruses 6598:handle 6389:Sphere 6104:  6094:  6023:  6015:  5997:  5790:  5780:  5725:  5717:  5702:  5685:  5641:Toroid 5611:Sphere 5309:matrix 5296:is an 5152:has a 4693:. Its 4446:Genus 4436:Genus 4130:  3792:, 2 ≤ 3785:smooth 3763:where 3087:module 3037:. The 3020:choose 3011:of an 3003:. The 2991:of an 2787:action 2501:-torus 2484:-plane 1305:volume 1187:, the 223:bagels 221:, and 203:volume 170:toroid 165:sphere 108:circle 68:sphere 32:Taurus 6568:Genus 6395:Torus 6032:(PDF) 6021:S2CID 5973:(PDF) 5913:(PDF) 5673:Notes 5298:array 5242:plane 5060:Homeo 5027:Homeo 4593:faces 4586:with 4491:with 4460:genus 4405:three 3986:< 3974:then 3626:) ~ ( 3622:+ 1, 3618:) ~ ( 3407:{4,4} 3351:twist 2102:, is 2071:from 2060:(the 2056:over 2052:as a 1951:, or 1299:of a 1177:When 1160:When 1144:When 1138:apple 1132:lemon 1124:< 1100:> 1095:When 435:< 389:> 356:Torus 338:one. 336:genus 120:donut 88:torus 6463:Disk 6332:2019 6227:2022 6201:2012 6175:2012 6149:2012 6118:2012 6102:PMID 6013:PMID 5955:2021 5895:2007 5844:2014 5818:2012 5778:ISBN 5723:ISBN 5715:ISBN 5700:ISBN 5683:ISBN 5506:OEIS 5304:-by- 4802:and 4685:The 4521:The 4514:and 3950:and 3767:and 3634:+ 1) 3333:For 3166:The 3007:-th 2987:The 2269:The 1892:and 1553:and 1269:< 1087:and 817:axis 459:as: 199:disk 184:and 155:(or 96:tori 86:, a 6538:or 6502:... 6271:at 6092:PMC 6082:doi 6078:109 6005:doi 5983:313 5770:doi 5288:In 5273:STL 5244:.) 5092:TOP 5088:MCG 4897:Aut 4863:Aut 4830:MCG 4664:. 4474:of 3946:If 3919:cos 3904:sin 3892:sin 3868:cos 3856:sin 3796:≤ ∞ 3739:sin 3724:cos 3709:sin 3694:cos 3528:= 3424:, 3409:1,0 3326:on 3208:of 2907:of 2836:An 2503:or 2437:). 2253:ABA 2064:). 2044:is 1165:= 0 1149:= 0 819:is 787:An 627:sin 584:sin 572:cos 520:cos 508:cos 346:). 292:of 244:: 228:In 188:. 159:or 122:or 110:in 98:or 92:pl. 82:In 6630:: 6314:. 6302:: 6247:. 6218:. 6139:. 6135:. 6108:. 6100:. 6090:. 6076:. 6072:. 6049:. 6027:. 6019:. 6011:. 6003:. 5993:. 5981:. 5975:. 5946:. 5915:. 5885:. 5864:. 5788:MR 5786:. 5776:. 5758:; 5721:, 5681:, 5508:). 5121:1. 4924:GL 4834:Ho 4705:GL 4623:+ 4619:− 4611:+ 4607:− 4582:A 4536:. 4462:" 4429:M* 4422:M* 4409:M* 4400:M* 4010:/4 4006:= 3978:, 3972:)) 3960:, 3630:, 3614:, 3558:: 3369:. 2901:. 2842:n- 2482:xz 2258:. 2143:. 2015:: 1955:, 1947:, 1566:− 1558:= 1538:+ 1530:= 1505:2π 1182:≥ 1112:= 1091:: 933:, 327:. 225:. 180:, 126:. 94:: 6362:e 6355:t 6348:v 6334:. 6318:. 6253:. 6229:. 6203:. 6177:. 6151:. 6120:. 6084:: 6007:: 5989:: 5957:. 5897:. 5870:. 5846:. 5820:. 5794:. 5772:: 5729:. 5706:. 5492:n 5488:n 5468:) 5465:n 5462:8 5459:+ 5454:2 5450:n 5446:3 5443:+ 5438:3 5434:n 5430:( 5424:6 5421:1 5415:= 5410:) 5404:1 5398:n 5391:n 5385:( 5380:+ 5375:) 5369:1 5363:n 5356:2 5353:+ 5350:n 5344:( 5329:n 5317:n 5306:n 5302:m 5280:2 5224:7 5221:= 5218:) 5211:7 5207:K 5201:( 5174:7 5170:K 5115:) 5110:n 5105:T 5100:( 5081:) 5076:n 5071:T 5066:( 5054:) 5049:n 5044:T 5039:( 5031:0 5020:1 4995:n 4990:R 4971:G 4969:( 4967:K 4947:. 4944:) 4940:Z 4936:, 4933:n 4930:( 4921:= 4918:) 4913:n 4908:Z 4903:( 4894:= 4891:) 4888:) 4885:X 4882:( 4877:1 4869:( 4860:= 4857:) 4852:n 4847:T 4842:( 4781:n 4776:Z 4752:n 4747:R 4725:) 4721:Z 4717:, 4714:n 4711:( 4671:) 4667:( 4633:N 4629:N 4625:F 4621:E 4617:V 4613:F 4609:E 4605:V 4508:n 4504:n 4493:g 4485:g 4481:g 4476:g 4468:g 4464:g 4448:g 4438:g 4396:M 4390:M 4338:3 4333:R 4321:C 4301:3 4296:R 4272:1 4268:C 4251:C 4243:C 4236:Q 4220:4 4215:R 4203:Q 4199:T 4197:⋅ 4195:Q 4191:S 4174:. 4170:} 4164:2 4161:1 4156:= 4151:2 4147:w 4143:+ 4138:2 4134:z 4127:, 4122:2 4119:1 4114:= 4109:2 4105:y 4101:+ 4096:2 4092:x 4083:3 4078:S 4070:) 4067:w 4064:, 4061:z 4058:, 4055:y 4052:, 4049:x 4046:( 4042:{ 4038:= 4035:T 4022:T 4008:π 4004:η 3999:S 3988:π 3984:η 3980:v 3976:u 3970:η 3966:η 3962:P 3958:R 3956:( 3952:P 3948:R 3931:. 3928:) 3925:v 3916:P 3913:, 3910:u 3901:) 3898:v 3889:P 3886:+ 3883:R 3880:( 3877:, 3874:u 3865:) 3862:v 3853:P 3850:+ 3847:R 3844:( 3841:( 3838:= 3835:) 3832:z 3829:, 3826:y 3823:, 3820:x 3817:( 3804:3 3794:k 3790:C 3769:P 3765:R 3748:) 3745:v 3736:P 3733:, 3730:v 3721:P 3718:, 3715:u 3706:R 3703:, 3700:u 3691:R 3688:( 3685:= 3682:) 3679:w 3676:, 3673:z 3670:, 3667:y 3664:, 3661:x 3658:( 3632:y 3628:x 3624:y 3620:x 3616:y 3612:x 3610:( 3590:2 3585:Z 3579:/ 3573:2 3568:R 3543:2 3538:Z 3526:L 3505:2 3500:Z 3476:2 3471:R 3459:L 3455:L 3453:/ 3439:2 3434:R 3343:n 3335:n 3328:n 3308:n 3303:S 3297:/ 3291:n 3286:T 3255:n 3251:) 3245:1 3240:S 3235:( 3232:= 3227:n 3222:T 3210:n 3202:n 3198:n 3194:n 3158:. 3152:2 3149:S 3147:/ 3145:T 3119:n 3103:n 3098:Z 3085:- 3083:Z 3075:Z 3059:n 3054:T 3044:( 3042:H 3035:n 3031:n 3023:k 3017:n 3013:n 3005:k 3001:n 2993:n 2966:n 2961:R 2949:n 2926:n 2921:Z 2909:T 2891:G 2887:T 2875:G 2838:n 2827:n 2823:n 2807:n 2802:Z 2771:n 2766:R 2754:n 2738:n 2733:R 2709:n 2704:T 2692:n 2676:2 2671:T 2647:1 2642:S 2637:= 2632:1 2627:T 2602:. 2597:n 2585:1 2580:S 2564:1 2559:S 2550:= 2545:n 2540:T 2525:n 2521:n 2517:n 2513:n 2509:n 2499:n 2466:n 2394:. 2390:Z 2382:Z 2375:) 2370:1 2365:S 2360:( 2355:1 2344:) 2339:1 2334:S 2329:( 2324:1 2316:= 2313:) 2308:2 2303:T 2298:( 2293:1 2256:B 2228:, 2225:) 2222:1 2219:+ 2216:y 2213:, 2210:x 2207:( 2201:) 2198:y 2195:, 2192:1 2189:+ 2186:x 2183:( 2177:) 2174:y 2171:, 2168:x 2165:( 2141:S 2125:3 2120:R 2087:3 2082:R 2058:S 2050:S 2042:S 2034:S 2026:C 2021:S 2017:S 1991:) 1985:( 1980:) 1976:( 1962:. 1909:r 1905:θ 1901:φ 1894:φ 1890:θ 1886:R 1862:. 1857:2 1853:) 1849:q 1843:p 1840:( 1837:) 1834:q 1831:+ 1828:p 1825:( 1820:2 1809:4 1806:1 1800:= 1795:2 1790:) 1785:2 1781:q 1775:p 1769:( 1763:) 1758:2 1754:q 1751:+ 1748:p 1742:( 1736:2 1728:2 1725:= 1718:V 1711:, 1708:) 1705:q 1699:p 1696:( 1693:) 1690:q 1687:+ 1684:p 1681:( 1676:2 1668:= 1664:) 1659:2 1655:q 1649:p 1643:( 1638:) 1633:2 1629:q 1626:+ 1623:p 1617:( 1611:2 1603:4 1600:= 1593:A 1575:2 1572:/ 1568:q 1564:p 1556:r 1547:2 1544:/ 1540:q 1536:p 1528:R 1523:q 1519:p 1512:r 1507:R 1485:. 1480:2 1476:r 1472:R 1467:2 1459:2 1456:= 1452:) 1448:R 1442:2 1438:( 1433:) 1427:2 1423:r 1415:( 1411:= 1404:V 1397:, 1394:r 1391:R 1386:2 1378:4 1375:= 1371:) 1367:R 1361:2 1357:( 1352:) 1348:r 1342:2 1338:( 1334:= 1327:A 1277:2 1273:r 1264:2 1260:z 1256:+ 1249:2 1243:) 1237:R 1227:2 1223:y 1219:+ 1214:2 1210:x 1202:( 1184:r 1180:R 1173:. 1170:R 1163:r 1157:. 1154:r 1147:R 1141:. 1126:r 1122:R 1114:r 1110:R 1102:r 1098:R 1089:r 1085:R 1069:. 1065:) 1059:2 1055:y 1051:+ 1046:2 1042:x 1037:( 1031:2 1027:R 1023:4 1020:= 1015:2 1010:) 1004:2 1000:r 991:2 987:R 983:+ 978:2 974:z 970:+ 965:2 961:y 957:+ 952:2 948:x 943:( 911:. 906:2 902:r 898:= 893:2 889:z 885:+ 878:2 872:) 866:R 856:2 852:y 848:+ 843:2 839:x 831:( 815:- 803:z 766:r 762:/ 758:R 735:r 712:R 689:, 686:) 680:2 677:, 674:0 671:[ 662:, 624:r 621:= 614:) 608:, 602:( 599:z 581:) 569:r 566:+ 563:R 560:( 557:= 550:) 544:, 538:( 535:y 517:) 505:r 502:+ 499:R 496:( 493:= 486:) 480:, 474:( 471:x 437:r 433:R 414:r 412:= 410:R 391:r 387:R 305:1 301:S 270:1 266:S 257:1 253:S 90:( 70:. 45:. 34:. 20:)

Index

Flat torus
Taurus
Solid torus
Torus (disambiguation)


degenerates
sphere

geometry
surface of revolution
circle
three-dimensional space
coplanar
axis of revolution
tangent
spindle torus
sphere
toroid
swim rings
inner tubes
ringette rings
solid torus
disk
volume
O-rings
lifebuoys
doughnuts
bagels
topology

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.