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Torus

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1925: 5510: 4234:(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 5257: 4349:, 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. 4246: 4544: 4533: 415: 3152: 4639: 392: 369: 3391: 1865: 4568: 40: 437: 64: 3367: 636: 1573: 4946: 48: 5120: 1488: 4467:
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
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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
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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'
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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
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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
451: 2393: 1503:, 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. 5237: 5467: 4173: 1860:{\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}}} 1307: 4813: 4962:, 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. 5004: 2601: 4420:
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.
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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.
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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
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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
5225:, 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 3930: 2272: 1578: 1312: 631:{\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}}} 4361:, 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 4391:
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
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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.
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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.
4941:{\displaystyle \operatorname {MCG} _{\operatorname {Ho} }(\mathbb {T} ^{n})=\operatorname {Aut} (\pi _{1}(X))=\operatorname {Aut} (\mathbb {Z} ^{n})=\operatorname {GL} (n,\mathbb {Z} ).} 5223: 6349: 5115:{\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.} 925: 5177: 2522: 271: 4996: 4782: 4753: 4339: 4302: 4221: 3544: 3506: 3477: 3440: 3104: 3060: 2967: 2927: 2808: 2772: 2739: 2710: 2677: 2126: 2088: 1182: 811: 5256: 3628:
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
1483:{\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}}} 4396:
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,
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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
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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
6017: 273:, 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 6342: 3125: 5494: 5240:
This construction shows the torus divided into seven regions, every one of which touches every other, meaning each must be assigned a unique color.
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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
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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
5678:, Author: Kozak Ana Maria, Pompeya Pastorelli Sonia, Verdanega Pedro Emilio, Editorial: McGraw-Hill, Edition 2007, 744 pages, language: Spanish 323:, 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 6335: 5770: 5715: 5675: 4377:" of the torus to contain one point for each conformal equivalence class, with the appropriate topology. It turns out that this moduli space 6288: 6177: 4341:
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
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exactly once. It is a torus because the edges are considered wraparound for the purpose of finding matrices. Its name comes from the
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paths commute. An equivalent statement may be imagined as two shoelaces passing through each other, then unwinding, then rewinding.
1976: 3642: 4795:, the mapping class group can be identified as the action on the first homology (or equivalently, first cohomology, or on the 67:
A ring torus with aspect ratio 3, the ratio between the diameters of the larger (magenta) circle and the smaller (red) circle.
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As the distance from the axis of revolution decreases, the ring torus becomes a horn torus, then a spindle torus, and finally
3204: 6058: 5462:{\displaystyle {\begin{pmatrix}n+2\\n-1\end{pmatrix}}+{\begin{pmatrix}n\\n-1\end{pmatrix}}={\tfrac {1}{6}}(n^{3}+3n^{2}+8n)} 3405:
with 1 vertex, 2 orthogonal edges, and one square face. It is seen here stereographically projected into 3-space as a torus.
4168:{\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\}.} 6039: 5579: 5564: 3194: 1892:
measures the same angle as it does in the spherical system, but is known as the "toroidal" direction. The center point of
152:). If the axis of revolution passes through the center of the circle, the surface is a degenerate torus, a double-covered 4689: 3636:
A simple 4-dimensional Euclidean embedding of a rectangular flat torus (more general than the square one) is as follows:
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with 1s as panels and 0s as holes in the mesh – with consistent orientation, every 3×3 matrix appears exactly once
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Padgett, Adele (2014). "FUNDAMENTAL GROUPS: MOTIVATION, COMPUTATION METHODS, AND APPLICATIONS" REA Program, Uchicago.
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while a genus one surface (without boundary) is the ordinary torus. The surfaces of higher genus are sometimes called
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surface is topologically equivalent to either the sphere or the connect sum of some number of tori, disks, and real
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embedding exists. This is solely an existence proof and does not provide explicit equations for such an embedding.
3795:-space requires one to stretch it, in which case it looks like a regular torus. For example, in the following map: 3395: 2775: 2037:
by a family of nested tori in this manner (with two degenerate circles), a fact which is important in the study of
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representing rotation around the tube and rotation around the torus' axis of revolution, respectively, where the
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in the work of Dmitri Tymoczko and collaborators (Felipe Posada, Michael Kolinas, et al.), being used to model
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to a topological torus as long as it does not intersect its own axis. A particular homeomorphism is given by
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The mapping class group of higher genus surfaces is much more complicated, and an area of active research.
3625:. This particular flat torus (and any uniformly scaled version of it) is known as the "square" flat torus. 2855:
with multiplication). Group multiplication on the torus is then defined by coordinate-wise multiplication.
6327: 5983: 4792: 4511: 4362: 4235: 3165: 2596:{\displaystyle \mathbb {T} ^{n}=\underbrace {\mathbb {S} ^{1}\times \cdots \times \mathbb {S} ^{1}} _{n}.} 313: 31: 6464: 6406: 5634: 5594: 4002: 2061: 1904: 781: 92: 5509: 5151: 2940:
with an integral inverse; these are just the integral matrices with determinant ±1. Making them act on
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of invertible integer matrices, which can be realized as linear maps on the universal covering space
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parts. (This assumes the pieces may not be rearranged but must remain in place for all cuts.)
5261: 4796: 4401: 4346: 3788: 3769: 2977: 2933: 2930: 2859: 2443: 2259: 2057: 1285: 1063:{\displaystyle \left(x^{2}+y^{2}+z^{2}+R^{2}-r^{2}\right)^{2}=4R^{2}\left(x^{2}+y^{2}\right).} 777: 6412: 6272: 6080: 6070: 5993: 5758: 5142: 4800: 4522: 4405: 4312:(continuously differentiable) embedding of a flat torus into 3-dimensional Euclidean space 4245: 3374: 3343: 3067: 2419: 1997: 1126: 1120: 919: 226: 140: 5780: 4543: 4532: 4251: 284: 6514: 6043: 5776: 5529: 5250: 4518: 4434: 4358: 3773: 3594: 3312: 3027: 2779: 2399: 2140: 1888:
As a torus has, effectively, two center points, the centerpoints of the angles are moved;
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The three classes of standard tori correspond to the three possible aspect ratios between
805: 274: 187: 6476: 3327: 3144: 1273:{\displaystyle {\textstyle {\bigl (}{\sqrt {x^{2}+y^{2}}}-R{\bigr )}^{2}}+z^{2}<r^{2}} 742: 5979: 3330:, the edge corresponding to the orbifold points where the two coordinates coincide. For 6085: 5604: 5589: 5559: 5544: 5534: 5236: 5146: 5138: 5134: 3761: 3151: 2997: 2886:, which (like tori) are compact connected abelian groups, which are not required to be 2852: 2466: 2411: 2026: 1993: 1281: 905:{\displaystyle {\textstyle {\bigl (}{\sqrt {x^{2}+y^{2}}}-R{\bigr )}^{2}}+z^{2}=r^{2}.} 787: 719: 696: 414: 309: 5682: 4638: 773:
of the torus. The typical doughnut confectionery has an aspect ratio of about 3 to 2.
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of the mapping class group splits (an identification of the torus as the quotient of
4579: 4515: 4460: 4373:. In the case of a torus, the constant curvature must be zero. Then one defines the " 4366: 3355: 2867: 2841: 2834: 2423: 222: 174: 5721: 3366: 6424: 6261: 6013: 5744: 5574: 4686:(the connected components of the homeomorphism group) is surjective onto the group 4548: 4537: 4504: 4500: 4374: 3390: 2893: 2092: 2042: 1297: 769: 391: 368: 332: 6233: 3128:
The configuration space of 2 not necessarily distinct points on the circle is the
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is sometimes used. In traditional spherical coordinates there are three measures,
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of an outermost point on the surface of the torus to the center, and the distance
6204: 3983:. In particular, for certain very specific choices of a square flat torus in the 3409:
A flat torus is a torus with the metric inherited from its representation as the
6304: 6122:"Mathematicians Produce First-Ever Image of Flat Torus in 3D | Mathematics" 3402: 2848: 2447: 2415: 2234: 2050: 915: 182: 104: 27: 4627:
The term "toroidal polyhedron" is also used for higher-genus polyhedra and for
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segment of the right edge of the repeated parallelogram is identified with the
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is the distance from the center of the tube to the center of the torus and the
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with the topological type of a torus are called toroidal polyhedra, and have
6592: 6481: 6238: 6152:"Mathematics: first-ever image of a flat torus in 3D – CNRS Web site – CNRS" 6075: 5997: 5855: 5748: 2844: 2819: 2461: 2034: 436: 278: 166: 6094: 6005: 5932: 5850: 3334:= 3 this quotient may be described as a solid torus with cross-section an 190:, rather than a circle, around an axis. A solid torus is a torus plus the 63: 6469: 5820: 4788: 4005:
solid tori subsets with the aforesaid flat torus surface as their common
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corresponds to the horn torus, which in effect is a torus with no "hole".
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does not touch the circle, the surface has a ring shape and is called a
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having this partitioning property include the square tori of the form
3925:{\displaystyle (x,y,z)=((R+P\sin v)\cos u,(R+P\sin v)\sin u,P\cos v).} 3201:
ordered, not necessarily distinct points on the circle. Symbolically,
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which is a torus of the largest possible dimension. Such maximal tori
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in the plane with itself. This produces a geometric object called the
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of symbols from an alphabet (often just 0 and 1) that contains every
4488: 4477: 2508:.) Recalling that the torus is the product space of two circles, the 2001: 1293: 230: 199: 191: 158: 153: 96: 56: 2810:(with the action being taken as vector addition). Equivalently, the 1869:
As a torus is the product of two circles, a modified version of the
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describes the self-intersecting spindle torus; its inner shell is a
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This article is about the mathematical surface. For the volume, see
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Poloidal direction (red arrow) and toroidal direction (blue arrow)
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is a Latin word for "a round, swelling, elevation, protuberance".
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Real-world objects that approximate a torus of revolution include
62: 46: 38: 156:. If the revolved curve is not a circle, the surface is called a 4678:(or the subgroup of diffeomorphisms) of the torus is studied in 2862:. This is due in part to the fact that in any compact Lie group 2446:. In fact, the conformal type of the torus is determined by the 6331: 3386:
can be projected into 3-dimensions and rotated on a fixed axis.
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is a compact abelian Lie group (when identified with the unit
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of radius √2. This topological torus is also often called the
1918: 5757:. Geometry and Computing. Vol. 9. Springer, Heidelberg. 1877:, the distance from the center of the coordinate system, and 1094:, the surface will be the familiar ring torus or anchor ring. 277:, but another way to do this is the Cartesian product of the 5920:
https://math.uchicago.edu/~may/REU2014/REUPapers/Padgett.pdf
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As examples, a genus zero surface (without boundary) is the
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in four dimensions performing a simple rotation through the
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in the above flat torus parametrization form a unit vector
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are positive constants determining the aspect ratio. It is
3742:{\displaystyle (x,y,z,w)=(R\cos u,R\sin u,P\cos v,P\sin v)} 1506:
Expressing the surface area and the volume by the distance
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A Guide to the Classification Theorem for Compact Surfaces
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1, 2, 6, 13, 24, 40, 62, 91, 128, 174, 230, ... (sequence
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for short. (This is the more typical meaning of the term "
5899:"Applications of the Clifford torus to material textures" 5483:= 0, not covered by the above formulas), are as follows: 4604:= 0. For any number of holes, the formula generalizes to 4416:
The other two cusps occur at the points corresponding in
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are easily constructed from automorphisms of the lattice
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The torus has a generalization to higher dimensions, the
6059:"Doc Madhattan: A flat torus in three dimensional space" 4799:, as these are all naturally isomorphic; also the first 3347:
corresponds to points with all 3 coordinates identical.
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Toroidal groups play an important part in the theory of
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These formulas are the same as for a cylinder of length
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inside the torus. Real-world objects that approximate a
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Compact topological surfaces and their immersions in 3D
4650: 3251:{\displaystyle \mathbb {T} ^{n}=(\mathbb {S} ^{1})^{n}} 2878:
have a controlling role to play in theory of connected
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by pasting the opposite edges together, described as a
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A ring torus with a selection of circles on its surface
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Fly-through cross-sections of a four-dimensional torus
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above, the torus will partition the 3-sphere into two
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under integral shifts in any coordinate. That is, the
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may be constructed by glueing together two congruent
4318: 4281: 4254: 4200: 4022: 3804: 3645: 3553: 3523: 3485: 3456: 3419: 3271: 3262:, not necessarily distinct points is accordingly the 3207: 3083: 3039: 2946: 2906: 2787: 2751: 2718: 2689: 2656: 2650:. The torus discussed above is the standard 2-torus, 2612: 2525: 2275: 2152: 2105: 2067: 1576: 1310: 1185: 928: 814: 790: 745: 722: 699: 646: 454: 287: 239: 2266:
of the fundamental group of the circle with itself:
6570: 6542: 6507: 6498: 6444: 6399: 6370: 6363: 6180:. Math.univ-lyon1.fr. 18 April 2012. Archived from 4998:gives a splitting, via the linear maps, as above): 4719:{\displaystyle \operatorname {GL} (n,\mathbb {Z} )} 5724:Encyclopédie des Formes Mathématiques Remarquables 5461: 5217: 5171: 5114: 4990: 4940: 4776: 4747: 4718: 4333: 4296: 4267: 4215: 4167: 3924: 3741: 3585: 3538: 3500: 3471: 3434: 3303: 3250: 3098: 3054: 2961: 2921: 2802: 2766: 2733: 2704: 2671: 2642: 2595: 2434:The 2-torus double-covers the 2-sphere, with four 2387: 2222: 2120: 2082: 1859: 1482: 1272: 1062: 904: 796: 759: 728: 705: 682: 630: 300: 265: 6275:Visualizing high dimensional data with flat torus 3586:{\displaystyle \mathbb {R} ^{2}/\mathbb {Z} ^{2}} 3304:{\displaystyle \mathbb {T} ^{n}/\mathbb {S} _{n}} 2643:{\displaystyle \mathbb {T} ^{1}=\mathbb {S} ^{1}} 5668:Nociones de Geometría Analítica y Álgebra Lineal 4447:there is a more general family of objects, the " 2223:{\displaystyle (x,y)\sim (x+1,y)\sim (x,y+1),\,} 1946:but its sources remain unclear because it lacks 6063:Proceedings of the National Academy of Sciences 5304:, which can be considered a special case where 4238:, which was proven in the 1950s, an isometric 683:{\displaystyle \theta ,\varphi \in [0,2\pi ),} 6343: 3508:. This gives the quotient the structure of a 1514:of an innermost point to the center (so that 1231: 1190: 1156:, the torus degenerates to the circle radius 1140:, the torus degenerates to the sphere radius 860: 819: 8: 4476:doughnuts stuck together side by side, or a 3311:, which is the quotient of the torus by the 2418:to the fundamental group (this follows from 6298:"Topology of a Twisted Torus – Numberphile" 6504: 6367: 6350: 6336: 6328: 5316:A solid torus of revolution can be cut by 5218:{\displaystyle \chi ({\mathsf {K_{7}}})=7} 5137:is seven, meaning every graph that can be 103:one full revolution about an axis that is 6205:"The Tortuous Geometry of the Flat Torus" 6084: 6074: 5987: 5441: 5425: 5406: 5371: 5330: 5328: 5198: 5193: 5192: 5184: 5161: 5156: 5155: 5153: 5097: 5093: 5092: 5079: 5063: 5059: 5058: 5036: 5032: 5031: 5018: 5006: 4982: 4978: 4977: 4974: 4928: 4927: 4900: 4896: 4895: 4864: 4839: 4835: 4834: 4821: 4815: 4768: 4764: 4763: 4760: 4739: 4735: 4734: 4731: 4709: 4708: 4691: 4365:guarantees that every Riemann surface is 4325: 4321: 4320: 4317: 4288: 4284: 4283: 4280: 4259: 4253: 4207: 4203: 4202: 4199: 4147: 4138: 4125: 4105: 4096: 4083: 4070: 4066: 4065: 4021: 3803: 3644: 3577: 3573: 3572: 3566: 3560: 3556: 3555: 3552: 3530: 3526: 3525: 3522: 3492: 3488: 3487: 3484: 3463: 3459: 3458: 3455: 3426: 3422: 3421: 3418: 3295: 3291: 3290: 3284: 3278: 3274: 3273: 3270: 3242: 3232: 3228: 3227: 3214: 3210: 3209: 3206: 3161:is an example of a torus in music theory. 3090: 3086: 3085: 3082: 3046: 3042: 3041: 3038: 2953: 2949: 2948: 2945: 2913: 2909: 2908: 2905: 2829:-torus in this sense is an example of an 2794: 2790: 2789: 2786: 2758: 2754: 2753: 2750: 2725: 2721: 2720: 2717: 2696: 2692: 2691: 2688: 2663: 2659: 2658: 2655: 2634: 2630: 2629: 2619: 2615: 2614: 2611: 2606:The standard 1-torus is just the circle: 2584: 2572: 2568: 2567: 2551: 2547: 2546: 2542: 2532: 2528: 2527: 2524: 2378: 2377: 2370: 2369: 2357: 2353: 2352: 2342: 2326: 2322: 2321: 2311: 2295: 2291: 2290: 2280: 2274: 2233:or, equivalently, as the quotient of the 2219: 2151: 2112: 2108: 2107: 2104: 2074: 2070: 2069: 2066: 1977:Learn how and when to remove this message 1885:, angles measured from the center point. 1844: 1807: 1791: 1782: 1760: 1733: 1723: 1663: 1634: 1608: 1598: 1577: 1575: 1467: 1454: 1414: 1373: 1311: 1309: 1264: 1251: 1236: 1230: 1229: 1214: 1201: 1195: 1189: 1188: 1186: 1184: 1046: 1033: 1018: 1002: 991: 978: 965: 952: 939: 927: 893: 880: 865: 859: 858: 843: 830: 824: 818: 817: 815: 813: 789: 784:for a torus radially symmetric about the 749: 744: 721: 698: 645: 578: 514: 455: 453: 292: 286: 257: 244: 238: 5254: 4527: 3319:letters (by permuting the coordinates). 2398:Intuitively speaking, this means that a 6057:Filippelli, Gianluigi (27 April 2012). 5736: 5475:The first 11 numbers of parts, for 0 ≤ 4275:isometric embedding of a flat torus in 3394:The simplest tiling of a flat torus is 3350:These orbifolds have found significant 3004:-torus is a free abelian group of rank 2822:by gluing the opposite faces together. 2056:The surface described above, given the 1300:of its torus are easily computed using 5199: 5195: 5162: 5158: 4194:is a rotation of 4-dimensional space 3106:whose generators are the duals of the 2969:in the usual way, one has the typical 2847:. This follows from the fact that the 180:A torus should not be confused with a 5827:from the original on 13 December 2014 4353:Conformal classification of flat tori 3979:/2 parameterize the unit 3-sphere as 3633:conditions are given up, see below). 3593:, which can also be described as the 3164:The Tonnetz is only truly a torus if 2840:. It is also an example of a compact 2512:-dimensional torus is the product of 2135:The torus can also be described as a 16:Doughnut-shaped surface of revolution 7: 5687:. Cambridge University Press, 2002. 4227:is a member of the Lie group SO(4). 2254:Turning a punctured torus inside-out 6312:Anders Sandberg (4 February 2014). 4755:that preserve the standard lattice 4387:may be turned into a compact space 80: 6279:Polydoes, doughnut-shaped polygons 6120:Enrico de Lazaro (18 April 2012). 6023:from the original on 25 July 2011. 5906:Journal of Applied Crystallography 5801:from the original on 29 April 2012 5795:"Equations for the Standard Torus" 5698:V. V. Nikulin, I. R. Shafarevich. 5179:can be embedded on the torus, and 3401:, constructed on the surface of a 2882:. Toroidal groups are examples of 2712:can be described as a quotient of 2679:. And similar to the 2-torus, the 1907:are more commonly used to discuss 14: 6101:from the original on 25 June 2012 5172:{\displaystyle {\mathsf {K_{7}}}} 4472:surface resembles the surface of 4230:It is known that there exists no 3189:-fold product of the circle, the 2012:. This can be viewed as lying in 429:: self-intersecting spindle torus 266:{\displaystyle S^{1}\times S^{1}} 6132:from the original on 1 June 2012 5959:"The Geometry of Musical Chords" 5957:Tymoczko, Dmitri (7 July 2006). 5876:Oxford English Dictionary Online 5508: 4991:{\displaystyle \mathbb {R} ^{n}} 4777:{\displaystyle \mathbb {Z} ^{n}} 4748:{\displaystyle \mathbb {R} ^{n}} 4637: 4542: 4531: 4334:{\displaystyle \mathbb {R} ^{3}} 4297:{\displaystyle \mathbb {R} ^{3}} 4216:{\displaystyle \mathbb {R} ^{4}} 3539:{\displaystyle \mathbb {Z} ^{2}} 3501:{\displaystyle \mathbb {Z} ^{2}} 3472:{\displaystyle \mathbb {R} ^{2}} 3435:{\displaystyle \mathbb {R} ^{2}} 3099:{\displaystyle \mathbb {Z} ^{n}} 3055:{\displaystyle \mathbb {T} ^{n}} 2962:{\displaystyle \mathbb {R} ^{n}} 2922:{\displaystyle \mathbb {Z} ^{n}} 2803:{\displaystyle \mathbb {Z} ^{n}} 2767:{\displaystyle \mathbb {R} ^{n}} 2734:{\displaystyle \mathbb {R} ^{n}} 2705:{\displaystyle \mathbb {T} ^{n}} 2672:{\displaystyle \mathbb {T} ^{2}} 2500:-torus", the other referring to 2465:A stereographic projection of a 2121:{\displaystyle \mathbb {R} ^{3}} 2083:{\displaystyle \mathbb {R} ^{3}} 1923: 1284:(and, hence, homeomorphic) to a 413: 390: 367: 186:, which is formed by rotating a 134:to the circle, the surface is a 6178:"Flat tori finally visualized!" 6034:Phillips, Tony (October 2006). 5897:De Graef, Marc (7 March 2024). 5722:"Tore (notion géométrique)" at 4514:for surfaces states that every 2422:since the fundamental group is 130:. If the axis of revolution is 5797:. Geom.uiuc.edu. 6 July 1995. 5456: 5418: 5206: 5189: 5106: 5103: 5088: 5072: 5069: 5054: 5045: 5042: 5027: 5011: 4932: 4918: 4906: 4891: 4879: 4876: 4870: 4857: 4845: 4830: 4713: 4699: 4058: 4034: 3916: 3889: 3868: 3853: 3832: 3829: 3823: 3805: 3736: 3676: 3670: 3646: 3239: 3223: 2363: 2348: 2332: 2317: 2301: 2286: 2213: 2195: 2189: 2171: 2165: 2153: 1841: 1828: 1825: 1813: 1696: 1684: 1681: 1669: 914:Algebraically eliminating the 674: 659: 602: 590: 569: 548: 538: 526: 505: 484: 474: 462: 1: 6040:American Mathematical Society 5565:Irrational winding of a torus 5320:(> 0) planes into at most 5145:of at most seven. (Since the 3258:. The configuration space of 3066:) can be identified with the 6273:"Relational Perspective Map" 5479:≤ 10 (including the case of 4529: 4507:are also occasionally used. 3352:applications to music theory 2814:-torus is obtained from the 2099:the topological torus into 2097:stereographically projecting 1296:of this solid torus and the 6036:"Take on Math in the Media" 5308:is 1 (one dimension). 4308:In April 2012, an explicit 4009:. One example is the torus 3764:to a regular torus but not 1909:magnetic confinement fusion 1871:spherical coordinate system 736:is the radius of the tube. 383:: ring torus or anchor ring 6641: 5580:Loewner's torus inequality 5248: 4560: 4432: 3787:) into Euclidean 3-space. 3597:under the identifications 3450:is a discrete subgroup of 3112: 2929:, which are classified by 2143:under the identifications 1896:is moved to the center of 1124:and its outer shell is an 640:using angular coordinates 25: 18: 6203:Hoang, Lê Nguyên (2016). 5878:. Oxford University Press 5763:10.1007/978-3-642-34364-3 5264:model of de Bruijn torus 4495:-holed tori (or, rarely, 4369:to one that has constant 3326:= 2, the quotient is the 3176:segment of the left edge. 3132:quotient of the 2-torus, 2262:of the torus is just the 1302:Pappus's centroid theorem 162:, as in a square toroid. 95:generated by revolving a 5640:Torus-based cryptography 4624:is the number of holes. 3380:stereographic projection 3168:is assumed, so that the 1932:This section includes a 19:Not to be confused with 6489:Sphere with three holes 6076:10.1073/pnas.1118478109 5998:10.1126/science.1126287 4953:Eilenberg–MacLane space 4631:of toroidal polyhedra. 4499:-fold tori). The terms 4413:has area equal to π/3. 2128:from the north pole of 2018:and is a subset of the 1961:more precise citations. 361:vertical cross-sections 150:self-intersecting torus 101:three-dimensional space 5463: 5274: 5241: 5219: 5173: 5116: 4992: 4951:Since the torus is an 4942: 4778: 4749: 4720: 4583: 4512:classification theorem 4367:conformally equivalent 4363:Uniformization theorem 4335: 4305: 4298: 4269: 4217: 4169: 3926: 3743: 3587: 3540: 3502: 3473: 3436: 3406: 3387: 3371: 3305: 3252: 3178: 3166:enharmonic equivalence 3148: 3100: 3056: 3014:. It follows that the 2963: 2923: 2866:one can always find a 2804: 2768: 2735: 2706: 2673: 2644: 2597: 2474: 2389: 2255: 2224: 2122: 2084: 1861: 1484: 1274: 1064: 906: 798: 761: 730: 707: 684: 632: 441: 302: 267: 68: 60: 55:into a double-covered 44: 32:Torus (disambiguation) 30:. For other uses, see 6407:Real projective plane 6392:Pretzel (genus 3) ... 5937:mathworld.wolfram.com 5700:Geometries and Groups 5635:Toroidal and poloidal 5595:Real projective plane 5464: 5260: 5239: 5220: 5174: 5139:embedded on the torus 5117: 4993: 4943: 4779: 4750: 4721: 4570: 4561:Further information: 4336: 4299: 4270: 4268:{\displaystyle C^{1}} 4248: 4218: 4170: 3927: 3744: 3588: 3541: 3503: 3474: 3437: 3393: 3377: 3369: 3342:; equivalently, as a 3306: 3253: 3154: 3127: 3101: 3057: 2964: 2924: 2805: 2769: 2736: 2707: 2674: 2645: 2598: 2464: 2390: 2253: 2225: 2123: 2085: 1905:toroidal and poloidal 1862: 1485: 1275: 1065: 907: 799: 782:Cartesian coordinates 762: 731: 708: 685: 633: 439: 303: 301:{\displaystyle S^{1}} 268: 93:surface of revolution 66: 50: 42: 6562:Euler characteristic 5570:Joint European Torus 5327: 5183: 5152: 5005: 4973: 4967:short exact sequence 4814: 4759: 4730: 4690: 4591:Euler characteristic 4316: 4279: 4252: 4223:, or in other words 4198: 4020: 3802: 3643: 3551: 3521: 3483: 3454: 3417: 3336:equilateral triangle 3269: 3205: 3081: 3037: 3022:-torus is 0 for all 3016:Euler characteristic 2944: 2904: 2870:; that is, a closed 2785: 2749: 2716: 2687: 2654: 2610: 2523: 2450:of the four points. 2273: 2150: 2103: 2065: 1574: 1308: 1183: 926: 812: 788: 743: 720: 697: 644: 452: 285: 237: 6296:(27 January 2014). 6258:Creation of a torus 5980:2006Sci...313...72T 5931:Weisstein, Eric W. 4684:mapping class group 4676:homeomorphism group 4573:toroidal polyhedron 4563:Toroidal polyhedron 4304:, with corrugations 4236:Nash-Kuiper theorem 3510:Riemannian manifold 3195:configuration space 3120:Configuration space 3115:Quasitoric manifold 3110:nontrivial cycles. 2485:, often called the 2481:n-dimensional torus 2440:conformal structure 2436:ramification points 2239:fundamental polygon 1290:Euclidean open disk 760:{\displaystyle R/r} 146:self-crossing torus 124:torus of revolution 6389:Number 8 (genus 2) 6231:Weisstein, Eric W. 6046:on 5 October 2008. 5848:Weisstein, Eric W. 5702:. Springer, 1987. 5684:Algebraic Topology 5655:Villarceau circles 5610:Surface (topology) 5540:Annulus (geometry) 5516:Mathematics portal 5459: 5416: 5397: 5362: 5302:De Bruijn sequence 5275: 5242: 5227:four color theorem 5215: 5169: 5112: 4988: 4938: 4774: 4745: 4716: 4680:geometric topology 4649:. You can help by 4584: 4557:Toroidal polyhedra 4484:handles attached. 4455:surfaces. A genus 4402:geodesic triangles 4371:Gaussian curvature 4331: 4306: 4294: 4265: 4213: 4165: 3922: 3739: 3630:Gaussian curvature 3583: 3536: 3498: 3469: 3432: 3407: 3388: 3372: 3301: 3248: 3179: 3149: 3096: 3052: 2986:free abelian group 2971:toral automorphism 2959: 2919: 2860:compact Lie groups 2800: 2764: 2731: 2702: 2669: 2640: 2593: 2589: 2582: 2516:circles. That is: 2504:holes or of genus 2475: 2457:-dimensional torus 2444:Weierstrass points 2385: 2256: 2220: 2118: 2080: 1934:list of references 1857: 1855: 1801: 1480: 1478: 1292:and a circle. The 1270: 1242: 1060: 902: 871: 794: 757: 726: 703: 680: 628: 626: 442: 298: 263: 221:, a ring torus is 126:, also known as a 120:axis of revolution 69: 61: 45: 6610: 6609: 6606: 6605: 6440: 6439: 6069:(19): 7218–7223. 5772:978-3-642-34363-6 5716:978-3-540-15281-1 5676:978-970-10-6596-9 5415: 4797:fundamental group 4667: 4666: 4554: 4553: 4523:projective planes 4443:In the theory of 4155: 4120: 4113: 3177: 2978:fundamental group 2973:on the quotient. 2934:integral matrices 2543: 2541: 2430:Two-sheeted cover 2260:fundamental group 2058:relative topology 1987: 1986: 1979: 1800: 1776: 1749: 1650: 1624: 1280:of this torus is 1220: 849: 797:{\displaystyle z} 729:{\displaystyle r} 706:{\displaystyle R} 359:Bottom-halves and 227:Cartesian product 202:, non-inflatable 6630: 6525:Triangulatedness 6505: 6368: 6364:Without boundary 6352: 6345: 6338: 6329: 6324: 6322: 6320: 6308: 6302: 6245: 6244: 6243: 6226: 6220: 6219: 6217: 6215: 6200: 6194: 6193: 6191: 6189: 6174: 6168: 6167: 6165: 6163: 6154:. Archived from 6148: 6142: 6141: 6139: 6137: 6117: 6111: 6110: 6108: 6106: 6088: 6078: 6054: 6048: 6047: 6042:. Archived from 6031: 6025: 6024: 6022: 5991: 5963: 5954: 5948: 5947: 5945: 5943: 5928: 5922: 5916: 5910: 5909: 5903: 5894: 5888: 5887: 5885: 5883: 5868: 5862: 5861: 5860: 5843: 5837: 5836: 5834: 5832: 5823:. Spatial Corp. 5817: 5811: 5810: 5808: 5806: 5791: 5785: 5784: 5741: 5518: 5513: 5512: 5492: 5468: 5466: 5465: 5460: 5446: 5445: 5430: 5429: 5417: 5408: 5402: 5401: 5367: 5366: 5271: 5259: 5224: 5222: 5221: 5216: 5205: 5204: 5203: 5202: 5178: 5176: 5175: 5170: 5168: 5167: 5166: 5165: 5143:chromatic number 5129:Coloring a torus 5121: 5119: 5118: 5113: 5102: 5101: 5096: 5084: 5083: 5068: 5067: 5062: 5041: 5040: 5035: 5023: 5022: 4997: 4995: 4994: 4989: 4987: 4986: 4981: 4947: 4945: 4944: 4939: 4931: 4905: 4904: 4899: 4869: 4868: 4844: 4843: 4838: 4826: 4825: 4801:cohomology group 4787:At the level of 4783: 4781: 4780: 4775: 4773: 4772: 4767: 4754: 4752: 4751: 4746: 4744: 4743: 4738: 4725: 4723: 4722: 4717: 4712: 4662: 4659: 4641: 4634: 4578: 4546: 4535: 4528: 4406:hyperbolic plane 4359:Riemann surfaces 4357:In the study of 4340: 4338: 4337: 4332: 4330: 4329: 4324: 4303: 4301: 4300: 4295: 4293: 4292: 4287: 4274: 4272: 4271: 4266: 4264: 4263: 4222: 4220: 4219: 4214: 4212: 4211: 4206: 4174: 4172: 4171: 4166: 4161: 4157: 4156: 4148: 4143: 4142: 4130: 4129: 4118: 4114: 4106: 4101: 4100: 4088: 4087: 4075: 4074: 4069: 4000: 3998: 3981:Hopf coordinates 3978: 3962: 3931: 3929: 3928: 3923: 3786: 3768:. It can not be 3748: 3746: 3745: 3740: 3624: 3592: 3590: 3589: 3584: 3582: 3581: 3576: 3570: 3565: 3564: 3559: 3546: 3545: 3543: 3542: 3537: 3535: 3534: 3529: 3507: 3505: 3504: 3499: 3497: 3496: 3491: 3478: 3476: 3475: 3470: 3468: 3467: 3462: 3441: 3439: 3438: 3433: 3431: 3430: 3425: 3344:triangular prism 3310: 3308: 3307: 3302: 3300: 3299: 3294: 3288: 3283: 3282: 3277: 3257: 3255: 3254: 3249: 3247: 3246: 3237: 3236: 3231: 3219: 3218: 3213: 3175: 3171: 3163: 3105: 3103: 3102: 3097: 3095: 3094: 3089: 3068:exterior algebra 3061: 3059: 3058: 3053: 3051: 3050: 3045: 2968: 2966: 2965: 2960: 2958: 2957: 2952: 2928: 2926: 2925: 2920: 2918: 2917: 2912: 2809: 2807: 2806: 2801: 2799: 2798: 2793: 2773: 2771: 2770: 2765: 2763: 2762: 2757: 2740: 2738: 2737: 2732: 2730: 2729: 2724: 2711: 2709: 2708: 2703: 2701: 2700: 2695: 2678: 2676: 2675: 2670: 2668: 2667: 2662: 2649: 2647: 2646: 2641: 2639: 2638: 2633: 2624: 2623: 2618: 2602: 2600: 2599: 2594: 2588: 2583: 2578: 2577: 2576: 2571: 2556: 2555: 2550: 2537: 2536: 2531: 2483: 2482: 2420:Hurewicz theorem 2414:of the torus is 2394: 2392: 2391: 2386: 2381: 2373: 2362: 2361: 2356: 2347: 2346: 2331: 2330: 2325: 2316: 2315: 2300: 2299: 2294: 2285: 2284: 2229: 2227: 2226: 2221: 2127: 2125: 2124: 2119: 2117: 2116: 2111: 2089: 2087: 2086: 2081: 2079: 2078: 2073: 1982: 1975: 1971: 1968: 1962: 1957:this section by 1948:inline citations 1927: 1926: 1919: 1899: 1895: 1891: 1884: 1880: 1876: 1866: 1864: 1863: 1858: 1856: 1849: 1848: 1812: 1811: 1802: 1793: 1787: 1786: 1781: 1777: 1772: 1761: 1754: 1750: 1745: 1734: 1728: 1727: 1668: 1667: 1655: 1651: 1646: 1635: 1629: 1625: 1620: 1609: 1603: 1602: 1569: 1568: 1566: 1565: 1562: 1559: 1541: 1540: 1538: 1537: 1534: 1531: 1513: 1509: 1502: 1498: 1489: 1487: 1486: 1481: 1479: 1472: 1471: 1459: 1458: 1443: 1439: 1424: 1420: 1419: 1418: 1378: 1377: 1362: 1358: 1343: 1339: 1279: 1277: 1276: 1271: 1269: 1268: 1256: 1255: 1243: 1241: 1240: 1235: 1234: 1221: 1219: 1218: 1206: 1205: 1196: 1194: 1193: 1175: 1161: 1155: 1145: 1139: 1117: 1105: 1093: 1079: 1075: 1069: 1067: 1066: 1061: 1056: 1052: 1051: 1050: 1038: 1037: 1023: 1022: 1007: 1006: 1001: 997: 996: 995: 983: 982: 970: 969: 957: 956: 944: 943: 920:quartic equation 911: 909: 908: 903: 898: 897: 885: 884: 872: 870: 869: 864: 863: 850: 848: 847: 835: 834: 825: 823: 822: 803: 801: 800: 795: 766: 764: 763: 758: 753: 735: 733: 732: 727: 712: 710: 709: 704: 689: 687: 686: 681: 637: 635: 634: 629: 627: 582: 518: 428: 417: 405: 394: 382: 371: 319:In the field of 307: 305: 304: 299: 297: 296: 272: 270: 269: 264: 262: 261: 249: 248: 82: 6640: 6639: 6633: 6632: 6631: 6629: 6628: 6627: 6613: 6612: 6611: 6602: 6566: 6543:Characteristics 6538: 6500: 6494: 6436: 6395: 6359: 6356: 6318: 6316: 6311: 6300: 6294:Séquin, Carlo H 6292: 6289:Wayback Machine 6254: 6249: 6248: 6234:"Torus Cutting" 6229: 6228: 6227: 6223: 6213: 6211: 6202: 6201: 6197: 6187: 6185: 6184:on 18 June 2012 6176: 6175: 6171: 6161: 6159: 6150: 6149: 6145: 6135: 6133: 6119: 6118: 6114: 6104: 6102: 6056: 6055: 6051: 6033: 6032: 6028: 6020: 5989:10.1.1.215.7449 5974:(5783): 72–74. 5961: 5956: 5955: 5951: 5941: 5939: 5930: 5929: 5925: 5917: 5913: 5901: 5896: 5895: 5891: 5881: 5879: 5870: 5869: 5865: 5846: 5845: 5844: 5840: 5830: 5828: 5819: 5818: 5814: 5804: 5802: 5793: 5792: 5788: 5773: 5743: 5742: 5738: 5733: 5681:Allen Hatcher. 5664: 5659: 5530:Algebraic torus 5514: 5507: 5504: 5488: 5437: 5421: 5396: 5395: 5383: 5382: 5372: 5361: 5360: 5348: 5347: 5331: 5325: 5324: 5314: 5312:Cutting a torus 5283:de Bruijn torus 5281:mathematics, a 5270: 5266: 5255: 5253: 5251:de Bruijn torus 5247: 5245:de Bruijn torus 5194: 5181: 5180: 5157: 5150: 5149: 5131: 5091: 5075: 5057: 5030: 5014: 5003: 5002: 4976: 4971: 4970: 4894: 4860: 4833: 4817: 4812: 4811: 4762: 4757: 4756: 4733: 4728: 4727: 4688: 4687: 4672: 4663: 4657: 4654: 4647:needs expansion 4576: 4565: 4559: 4547: 4536: 4459:surface is the 4441: 4431: 4355: 4347:surface normals 4319: 4314: 4313: 4282: 4277: 4276: 4255: 4250: 4249: 4201: 4196: 4195: 4134: 4121: 4092: 4079: 4064: 4033: 4029: 4018: 4017: 3996: 3991: 3976: 3944: 3800: 3799: 3777: 3641: 3640: 3598: 3595:Cartesian plane 3571: 3554: 3549: 3548: 3524: 3519: 3518: 3513: 3486: 3481: 3480: 3457: 3452: 3451: 3420: 3415: 3414: 3399: 3364: 3313:symmetric group 3289: 3272: 3267: 3266: 3238: 3226: 3208: 3203: 3202: 3173: 3169: 3162: 3143:, which is the 3142: 3122: 3117: 3084: 3079: 3078: 3040: 3035: 3034: 3028:cohomology ring 2947: 2942: 2941: 2907: 2902: 2901: 2853:complex numbers 2788: 2783: 2782: 2778:of the integer 2752: 2747: 2746: 2719: 2714: 2713: 2690: 2685: 2684: 2657: 2652: 2651: 2628: 2613: 2608: 2607: 2566: 2545: 2544: 2526: 2521: 2520: 2480: 2479: 2459: 2432: 2351: 2338: 2320: 2307: 2289: 2276: 2271: 2270: 2148: 2147: 2141:Cartesian plane 2106: 2101: 2100: 2068: 2063: 2062: 1996:defined as the 1992:, a torus is a 1983: 1972: 1966: 1963: 1952: 1938:related reading 1928: 1924: 1917: 1903:In modern use, 1897: 1893: 1889: 1882: 1878: 1874: 1854: 1853: 1840: 1803: 1762: 1756: 1755: 1735: 1729: 1719: 1709: 1703: 1702: 1659: 1636: 1630: 1610: 1604: 1594: 1584: 1572: 1571: 1563: 1560: 1551: 1550: 1548: 1543: 1535: 1532: 1523: 1522: 1520: 1515: 1511: 1507: 1500: 1493: 1477: 1476: 1463: 1450: 1429: 1425: 1410: 1406: 1402: 1395: 1389: 1388: 1369: 1348: 1344: 1329: 1325: 1318: 1306: 1305: 1260: 1247: 1228: 1210: 1197: 1181: 1180: 1167: 1157: 1150: 1141: 1134: 1109: 1097: 1085: 1077: 1073: 1042: 1029: 1028: 1024: 1014: 987: 974: 961: 948: 935: 934: 930: 929: 924: 923: 889: 876: 857: 839: 826: 810: 809: 786: 785: 741: 740: 718: 717: 695: 694: 642: 641: 625: 624: 605: 584: 583: 541: 520: 519: 477: 450: 449: 444:A torus can be 434: 433: 432: 431: 430: 420: 418: 409: 408: 407: 397: 395: 386: 385: 384: 374: 372: 363: 362: 360: 354: 341: 312:, a surface in 288: 283: 282: 275:Euclidean space 253: 240: 235: 234: 35: 24: 17: 12: 11: 5: 6638: 6637: 6634: 6626: 6625: 6615: 6614: 6608: 6607: 6604: 6603: 6601: 6600: 6595: 6589: 6583: 6580: 6574: 6572: 6568: 6567: 6565: 6564: 6559: 6554: 6546: 6544: 6540: 6539: 6537: 6536: 6531: 6522: 6517: 6511: 6509: 6502: 6496: 6495: 6493: 6492: 6486: 6485: 6484: 6474: 6473: 6472: 6467: 6459: 6458: 6457: 6448: 6446: 6442: 6441: 6438: 6437: 6435: 6434: 6431:Dyck's surface 6428: 6422: 6421: 6420: 6415: 6403: 6401: 6400:Non-orientable 6397: 6396: 6394: 6393: 6390: 6387: 6381: 6374: 6372: 6365: 6361: 6360: 6357: 6355: 6354: 6347: 6340: 6332: 6326: 6325: 6309: 6281: 6276: 6270: 6264: 6253: 6252:External links 6250: 6247: 6246: 6221: 6195: 6169: 6158:on 5 July 2012 6143: 6112: 6049: 6026: 5949: 5923: 5911: 5889: 5863: 5838: 5812: 5786: 5771: 5735: 5734: 5732: 5729: 5728: 5727: 5719: 5696: 5679: 5663: 5660: 5658: 5657: 5652: 5647: 5642: 5637: 5632: 5627: 5622: 5617: 5612: 5607: 5605:Spiric section 5602: 5597: 5592: 5590:Period lattice 5587: 5582: 5577: 5572: 5567: 5562: 5560:Elliptic curve 5557: 5552: 5547: 5545:Clifford torus 5542: 5537: 5535:Angenent torus 5532: 5527: 5521: 5520: 5519: 5503: 5500: 5499: 5498: 5470: 5469: 5458: 5455: 5452: 5449: 5444: 5440: 5436: 5433: 5428: 5424: 5420: 5414: 5411: 5405: 5400: 5394: 5391: 5388: 5385: 5384: 5381: 5378: 5377: 5375: 5370: 5365: 5359: 5356: 5353: 5350: 5349: 5346: 5343: 5340: 5337: 5336: 5334: 5313: 5310: 5268: 5249:Main article: 5246: 5243: 5214: 5211: 5208: 5201: 5197: 5191: 5188: 5164: 5160: 5147:complete graph 5135:Heawood number 5130: 5127: 5123: 5122: 5111: 5108: 5105: 5100: 5095: 5090: 5087: 5082: 5078: 5074: 5071: 5066: 5061: 5056: 5053: 5050: 5047: 5044: 5039: 5034: 5029: 5026: 5021: 5017: 5013: 5010: 4985: 4980: 4949: 4948: 4937: 4934: 4930: 4926: 4923: 4920: 4917: 4914: 4911: 4908: 4903: 4898: 4893: 4890: 4887: 4884: 4881: 4878: 4875: 4872: 4867: 4863: 4859: 4856: 4853: 4850: 4847: 4842: 4837: 4832: 4829: 4824: 4820: 4803:generates the 4771: 4766: 4742: 4737: 4715: 4711: 4707: 4704: 4701: 4698: 4695: 4671: 4668: 4665: 4664: 4644: 4642: 4558: 4555: 4552: 4551: 4540: 4433:Main article: 4430: 4423: 4354: 4351: 4328: 4323: 4291: 4286: 4262: 4258: 4210: 4205: 4178:Other tori in 4176: 4175: 4164: 4160: 4154: 4151: 4146: 4141: 4137: 4133: 4128: 4124: 4117: 4112: 4109: 4104: 4099: 4095: 4091: 4086: 4082: 4078: 4073: 4068: 4063: 4060: 4057: 4054: 4051: 4048: 4045: 4042: 4039: 4036: 4032: 4028: 4025: 3933: 3932: 3921: 3918: 3915: 3912: 3909: 3906: 3903: 3900: 3897: 3894: 3891: 3888: 3885: 3882: 3879: 3876: 3873: 3870: 3867: 3864: 3861: 3858: 3855: 3852: 3849: 3846: 3843: 3840: 3837: 3834: 3831: 3828: 3825: 3822: 3819: 3816: 3813: 3810: 3807: 3750: 3749: 3738: 3735: 3732: 3729: 3726: 3723: 3720: 3717: 3714: 3711: 3708: 3705: 3702: 3699: 3696: 3693: 3690: 3687: 3684: 3681: 3678: 3675: 3672: 3669: 3666: 3663: 3660: 3657: 3654: 3651: 3648: 3580: 3575: 3569: 3563: 3558: 3533: 3528: 3495: 3490: 3479:isomorphic to 3466: 3461: 3429: 3424: 3397: 3363: 3360: 3356:musical triads 3298: 3293: 3287: 3281: 3276: 3245: 3241: 3235: 3230: 3225: 3222: 3217: 3212: 3193:-torus is the 3185:-torus is the 3140: 3121: 3118: 3093: 3088: 3049: 3044: 2998:homology group 2956: 2951: 2916: 2911: 2797: 2792: 2761: 2756: 2728: 2723: 2699: 2694: 2666: 2661: 2637: 2632: 2627: 2622: 2617: 2604: 2603: 2592: 2587: 2581: 2575: 2570: 2565: 2562: 2559: 2554: 2549: 2540: 2535: 2530: 2495: 2491: 2484: 2467:Clifford torus 2458: 2452: 2431: 2428: 2412:homology group 2396: 2395: 2384: 2380: 2376: 2372: 2368: 2365: 2360: 2355: 2350: 2345: 2341: 2337: 2334: 2329: 2324: 2319: 2314: 2310: 2306: 2303: 2298: 2293: 2288: 2283: 2279: 2264:direct product 2231: 2230: 2218: 2215: 2212: 2209: 2206: 2203: 2200: 2197: 2194: 2191: 2188: 2185: 2182: 2179: 2176: 2173: 2170: 2167: 2164: 2161: 2158: 2155: 2115: 2110: 2077: 2072: 2027:Clifford torus 1994:closed surface 1985: 1984: 1942:external links 1931: 1929: 1922: 1916: 1913: 1852: 1847: 1843: 1839: 1836: 1833: 1830: 1827: 1824: 1821: 1818: 1815: 1810: 1806: 1799: 1796: 1790: 1785: 1780: 1775: 1771: 1768: 1765: 1759: 1753: 1748: 1744: 1741: 1738: 1732: 1726: 1722: 1718: 1715: 1712: 1710: 1708: 1705: 1704: 1701: 1698: 1695: 1692: 1689: 1686: 1683: 1680: 1677: 1674: 1671: 1666: 1662: 1658: 1654: 1649: 1645: 1642: 1639: 1633: 1628: 1623: 1619: 1616: 1613: 1607: 1601: 1597: 1593: 1590: 1587: 1585: 1583: 1580: 1579: 1475: 1470: 1466: 1462: 1457: 1453: 1449: 1446: 1442: 1438: 1435: 1432: 1428: 1423: 1417: 1413: 1409: 1405: 1401: 1398: 1396: 1394: 1391: 1390: 1387: 1384: 1381: 1376: 1372: 1368: 1365: 1361: 1357: 1354: 1351: 1347: 1342: 1338: 1335: 1332: 1328: 1324: 1321: 1319: 1317: 1314: 1313: 1267: 1263: 1259: 1254: 1250: 1246: 1239: 1233: 1227: 1224: 1217: 1213: 1209: 1204: 1200: 1192: 1164: 1163: 1147: 1131: 1107: 1095: 1059: 1055: 1049: 1045: 1041: 1036: 1032: 1027: 1021: 1017: 1013: 1010: 1005: 1000: 994: 990: 986: 981: 977: 973: 968: 964: 960: 955: 951: 947: 942: 938: 933: 901: 896: 892: 888: 883: 879: 875: 868: 862: 856: 853: 846: 842: 838: 833: 829: 821: 793: 767:is called the 756: 752: 748: 725: 702: 679: 676: 673: 670: 667: 664: 661: 658: 655: 652: 649: 623: 620: 617: 614: 611: 608: 606: 604: 601: 598: 595: 592: 589: 586: 585: 581: 577: 574: 571: 568: 565: 562: 559: 556: 553: 550: 547: 544: 542: 540: 537: 534: 531: 528: 525: 522: 521: 517: 513: 510: 507: 504: 501: 498: 495: 492: 489: 486: 483: 480: 478: 476: 473: 470: 467: 464: 461: 458: 457: 419: 412: 411: 410: 396: 389: 388: 387: 373: 366: 365: 364: 358: 357: 356: 355: 353: 350: 340: 337: 310:Clifford torus 295: 291: 260: 256: 252: 247: 243: 175:ringette rings 15: 13: 10: 9: 6: 4: 3: 2: 6636: 6635: 6624: 6621: 6620: 6618: 6599: 6596: 6594: 6590: 6588: 6584: 6582:Making a hole 6581: 6579: 6578:Connected sum 6576: 6575: 6573: 6569: 6563: 6560: 6558: 6555: 6552: 6548: 6547: 6545: 6541: 6535: 6534:Orientability 6532: 6530: 6526: 6523: 6521: 6518: 6516: 6515:Connectedness 6513: 6512: 6510: 6506: 6503: 6497: 6490: 6487: 6483: 6480: 6479: 6478: 6475: 6471: 6468: 6466: 6463: 6462: 6460: 6455: 6454: 6453: 6450: 6449: 6447: 6445:With boundary 6443: 6433:(genus 3) ... 6432: 6429: 6426: 6423: 6419: 6418:Roman surface 6416: 6414: 6413:Boy's surface 6410: 6409: 6408: 6405: 6404: 6402: 6398: 6391: 6388: 6385: 6382: 6379: 6376: 6375: 6373: 6369: 6366: 6362: 6353: 6348: 6346: 6341: 6339: 6334: 6333: 6330: 6315: 6314:"Torus Earth" 6310: 6306: 6299: 6295: 6290: 6286: 6282: 6280: 6277: 6274: 6271: 6268: 6265: 6263: 6259: 6256: 6255: 6251: 6241: 6240: 6235: 6232: 6225: 6222: 6210: 6206: 6199: 6196: 6183: 6179: 6173: 6170: 6157: 6153: 6147: 6144: 6131: 6127: 6123: 6116: 6113: 6100: 6096: 6092: 6087: 6082: 6077: 6072: 6068: 6064: 6060: 6053: 6050: 6045: 6041: 6037: 6030: 6027: 6019: 6015: 6011: 6007: 6003: 5999: 5995: 5990: 5985: 5981: 5977: 5973: 5969: 5968: 5960: 5953: 5950: 5938: 5934: 5927: 5924: 5921: 5915: 5912: 5907: 5900: 5893: 5890: 5877: 5873: 5867: 5864: 5858: 5857: 5852: 5849: 5842: 5839: 5826: 5822: 5816: 5813: 5800: 5796: 5790: 5787: 5782: 5778: 5774: 5768: 5764: 5760: 5756: 5755: 5750: 5746: 5745:Gallier, Jean 5740: 5737: 5730: 5726: 5725: 5720: 5717: 5713: 5709: 5708:3-540-15281-4 5705: 5701: 5697: 5694: 5693:0-521-79540-0 5690: 5686: 5685: 5680: 5677: 5673: 5669: 5666: 5665: 5661: 5656: 5653: 5651: 5650:Umbilic torus 5648: 5646: 5643: 5641: 5638: 5636: 5633: 5631: 5628: 5626: 5625:Toric variety 5623: 5621: 5620:Toric section 5618: 5616: 5613: 5611: 5608: 5606: 5603: 5601: 5598: 5596: 5593: 5591: 5588: 5586: 5585:Maximal torus 5583: 5581: 5578: 5576: 5573: 5571: 5568: 5566: 5563: 5561: 5558: 5556: 5555:Dupin cyclide 5553: 5551: 5550:Complex torus 5548: 5546: 5543: 5541: 5538: 5536: 5533: 5531: 5528: 5526: 5523: 5522: 5517: 5511: 5506: 5501: 5496: 5491: 5486: 5485: 5484: 5482: 5478: 5473: 5453: 5450: 5447: 5442: 5438: 5434: 5431: 5426: 5422: 5412: 5409: 5403: 5398: 5392: 5389: 5386: 5379: 5373: 5368: 5363: 5357: 5354: 5351: 5344: 5341: 5338: 5332: 5323: 5322: 5321: 5319: 5311: 5309: 5307: 5303: 5299: 5296: 5292: 5288: 5284: 5280: 5279:combinatorial 5272: 5263: 5258: 5252: 5244: 5238: 5234: 5232: 5228: 5212: 5209: 5186: 5148: 5144: 5140: 5136: 5128: 5126: 5109: 5098: 5085: 5080: 5076: 5064: 5051: 5048: 5037: 5024: 5019: 5015: 5008: 5001: 5000: 4999: 4983: 4968: 4963: 4961: 4957: 4954: 4935: 4924: 4921: 4915: 4912: 4909: 4901: 4888: 4885: 4882: 4873: 4865: 4861: 4854: 4851: 4848: 4840: 4827: 4822: 4818: 4810: 4809: 4808: 4806: 4802: 4798: 4794: 4790: 4785: 4769: 4740: 4705: 4702: 4696: 4693: 4685: 4681: 4677: 4670:Automorphisms 4669: 4661: 4652: 4648: 4645:This section 4643: 4640: 4636: 4635: 4632: 4630: 4625: 4623: 4619: 4615: 4611: 4607: 4603: 4599: 4595: 4592: 4588: 4581: 4580:quadrilateral 4574: 4569: 4564: 4556: 4550: 4545: 4541: 4539: 4534: 4530: 4526: 4524: 4520: 4517: 4513: 4508: 4506: 4502: 4498: 4494: 4490: 4485: 4483: 4479: 4475: 4471: 4466: 4462: 4461:connected sum 4458: 4454: 4450: 4446: 4440: 4438: 4428: 4424: 4422: 4419: 4414: 4412: 4407: 4403: 4399: 4395: 4390: 4386: 4382: 4380: 4376: 4372: 4368: 4364: 4360: 4352: 4350: 4348: 4344: 4326: 4311: 4289: 4260: 4256: 4247: 4243: 4241: 4237: 4233: 4228: 4226: 4208: 4193: 4189: 4185: 4181: 4162: 4158: 4152: 4149: 4144: 4139: 4135: 4131: 4126: 4122: 4115: 4110: 4107: 4102: 4097: 4093: 4089: 4084: 4080: 4076: 4071: 4061: 4055: 4052: 4049: 4046: 4043: 4040: 4037: 4030: 4026: 4023: 4016: 4015: 4014: 4012: 4008: 4004: 3994: 3989: 3986: 3982: 3974: 3971:, and 0 < 3970: 3966: 3960: 3956: 3952: 3948: 3942: 3938: 3919: 3913: 3910: 3907: 3904: 3901: 3898: 3895: 3892: 3886: 3883: 3880: 3877: 3874: 3871: 3865: 3862: 3859: 3856: 3850: 3847: 3844: 3841: 3838: 3835: 3826: 3820: 3817: 3814: 3811: 3808: 3798: 3797: 3796: 3794: 3790: 3784: 3780: 3775: 3771: 3767: 3763: 3762:diffeomorphic 3759: 3755: 3733: 3730: 3727: 3724: 3721: 3718: 3715: 3712: 3709: 3706: 3703: 3700: 3697: 3694: 3691: 3688: 3685: 3682: 3679: 3673: 3667: 3664: 3661: 3658: 3655: 3652: 3649: 3639: 3638: 3637: 3634: 3631: 3626: 3622: 3618: 3614: 3610: 3606: 3602: 3596: 3578: 3567: 3561: 3531: 3516: 3511: 3493: 3464: 3449: 3445: 3427: 3412: 3404: 3400: 3392: 3385: 3381: 3376: 3368: 3361: 3359: 3357: 3353: 3348: 3345: 3341: 3337: 3333: 3329: 3325: 3320: 3318: 3314: 3296: 3285: 3279: 3265: 3261: 3243: 3233: 3220: 3215: 3200: 3196: 3192: 3188: 3184: 3167: 3160: 3159: 3153: 3146: 3139: 3135: 3131: 3126: 3119: 3116: 3111: 3109: 3091: 3077: 3073: 3069: 3065: 3047: 3032: 3029: 3025: 3021: 3017: 3013: 3010: 3007: 3003: 2999: 2995: 2991: 2987: 2983: 2979: 2974: 2972: 2954: 2939: 2935: 2932: 2914: 2899: 2895: 2894:Automorphisms 2891: 2889: 2885: 2881: 2877: 2873: 2869: 2868:maximal torus 2865: 2861: 2856: 2854: 2850: 2846: 2843: 2839: 2836: 2832: 2828: 2823: 2821: 2818:-dimensional 2817: 2813: 2795: 2781: 2777: 2759: 2744: 2726: 2697: 2682: 2664: 2635: 2625: 2620: 2590: 2585: 2579: 2573: 2563: 2560: 2557: 2552: 2538: 2533: 2519: 2518: 2517: 2515: 2511: 2507: 2503: 2499: 2493: 2489: 2486: 2478: 2472: 2468: 2463: 2456: 2453: 2451: 2449: 2445: 2441: 2437: 2429: 2427: 2425: 2421: 2417: 2413: 2408: 2404: 2401: 2382: 2374: 2366: 2358: 2343: 2339: 2335: 2327: 2312: 2308: 2304: 2296: 2281: 2277: 2269: 2268: 2267: 2265: 2261: 2252: 2248: 2246: 2243: 2240: 2236: 2216: 2210: 2207: 2204: 2201: 2198: 2192: 2186: 2183: 2180: 2177: 2174: 2168: 2162: 2159: 2156: 2146: 2145: 2144: 2142: 2138: 2133: 2131: 2113: 2098: 2094: 2090: 2075: 2059: 2054: 2052: 2048: 2044: 2040: 2036: 2032: 2028: 2024: 2021: 2017: 2016: 2011: 2008: ×  2007: 2003: 1999: 1995: 1991: 1990:Topologically 1981: 1978: 1970: 1967:November 2015 1960: 1956: 1950: 1949: 1943: 1939: 1935: 1930: 1921: 1920: 1914: 1912: 1910: 1906: 1901: 1886: 1872: 1867: 1850: 1845: 1837: 1834: 1831: 1822: 1819: 1816: 1808: 1804: 1797: 1794: 1788: 1783: 1778: 1773: 1769: 1766: 1763: 1757: 1751: 1746: 1742: 1739: 1736: 1730: 1724: 1720: 1716: 1713: 1711: 1706: 1699: 1693: 1690: 1687: 1678: 1675: 1672: 1664: 1660: 1656: 1652: 1647: 1643: 1640: 1637: 1631: 1626: 1621: 1617: 1614: 1611: 1605: 1599: 1595: 1591: 1588: 1586: 1581: 1558: 1554: 1546: 1530: 1526: 1518: 1504: 1497: 1490: 1473: 1468: 1464: 1460: 1455: 1451: 1447: 1444: 1440: 1436: 1433: 1430: 1426: 1421: 1415: 1411: 1407: 1403: 1399: 1397: 1392: 1385: 1382: 1379: 1374: 1370: 1366: 1363: 1359: 1355: 1352: 1349: 1345: 1340: 1336: 1333: 1330: 1326: 1322: 1320: 1315: 1303: 1299: 1295: 1291: 1287: 1283: 1282:diffeomorphic 1265: 1261: 1257: 1252: 1248: 1244: 1237: 1225: 1222: 1215: 1211: 1207: 1202: 1198: 1179: 1174: 1170: 1160: 1153: 1148: 1144: 1137: 1132: 1129: 1128: 1123: 1122: 1116: 1112: 1108: 1104: 1100: 1096: 1092: 1088: 1083: 1082: 1081: 1070: 1057: 1053: 1047: 1043: 1039: 1034: 1030: 1025: 1019: 1015: 1011: 1008: 1003: 998: 992: 988: 984: 979: 975: 971: 966: 962: 958: 953: 949: 945: 940: 936: 931: 921: 917: 912: 899: 894: 890: 886: 881: 877: 873: 866: 854: 851: 844: 840: 836: 831: 827: 807: 791: 783: 779: 774: 772: 771: 754: 750: 746: 737: 723: 716: 700: 693: 677: 671: 668: 665: 662: 656: 653: 650: 647: 638: 621: 618: 615: 612: 609: 607: 599: 596: 593: 587: 579: 575: 572: 566: 563: 560: 557: 554: 551: 545: 543: 535: 532: 529: 523: 515: 511: 508: 502: 499: 496: 493: 490: 487: 481: 479: 471: 468: 465: 459: 447: 438: 427: 423: 416: 404: 400: 393: 381: 377: 370: 351: 349: 347: 346: 338: 336: 334: 328: 326: 322: 317: 315: 311: 293: 289: 280: 276: 258: 254: 250: 245: 241: 232: 228: 224: 220: 215: 213: 209: 205: 201: 197: 193: 189: 185: 184: 178: 176: 172: 168: 163: 161: 160: 155: 151: 147: 143: 142: 141:spindle torus 137: 133: 129: 125: 121: 116: 114: 110: 106: 102: 98: 94: 90: 86: 78: 74: 65: 58: 54: 49: 41: 37: 33: 29: 22: 6477:Möbius strip 6425:Klein bottle 6383: 6317:. Retrieved 6285:Ghostarchive 6283:Archived at 6262:cut-the-knot 6237: 6224: 6212:. Retrieved 6208: 6198: 6186:. Retrieved 6182:the original 6172: 6160:. Retrieved 6156:the original 6146: 6134:. Retrieved 6126:Sci-News.com 6125: 6115: 6103:. Retrieved 6066: 6062: 6052: 6044:the original 6029: 5971: 5965: 5952: 5940:. Retrieved 5936: 5926: 5914: 5905: 5892: 5880:. Retrieved 5875: 5866: 5854: 5841: 5829:. Retrieved 5815: 5803:. Retrieved 5789: 5753: 5739: 5723: 5699: 5683: 5667: 5575:Klein bottle 5480: 5476: 5474: 5471: 5317: 5315: 5305: 5294: 5290: 5282: 5276: 5265: 5133:The torus's 5132: 5124: 4964: 4959: 4955: 4950: 4786: 4673: 4655: 4651:adding to it 4646: 4626: 4621: 4617: 4613: 4609: 4605: 4601: 4597: 4593: 4585: 4509: 4505:triple torus 4501:double torus 4496: 4492: 4486: 4481: 4473: 4469: 4464: 4456: 4452: 4442: 4436: 4426: 4417: 4415: 4410: 4397: 4393: 4388: 4384: 4383: 4378: 4375:moduli space 4356: 4309: 4307: 4239: 4231: 4229: 4224: 4191: 4187: 4183: 4179: 4177: 4010: 3992: 3987: 3972: 3968: 3964: 3958: 3954: 3950: 3946: 3940: 3936: 3934: 3792: 3782: 3778: 3770:analytically 3757: 3753: 3751: 3635: 3627: 3620: 3616: 3612: 3608: 3604: 3600: 3514: 3447: 3443: 3408: 3383: 3349: 3331: 3328:Möbius strip 3323: 3321: 3316: 3259: 3198: 3190: 3186: 3182: 3180: 3156: 3145:Möbius strip 3137: 3133: 3107: 3071: 3063: 3030: 3023: 3019: 3011: 3005: 3001: 2993: 2989: 2984:-torus is a 2981: 2975: 2970: 2937: 2897: 2892: 2879: 2875: 2863: 2857: 2833:dimensional 2830: 2826: 2824: 2815: 2811: 2742: 2680: 2605: 2513: 2509: 2505: 2501: 2497: 2487: 2476: 2470: 2454: 2433: 2409: 2405: 2397: 2257: 2244: 2241: 2232: 2134: 2129: 2093:homeomorphic 2055: 2046: 2043:fiber bundle 2038: 2030: 2022: 2014: 2009: 2005: 1988: 1973: 1964: 1953:Please help 1945: 1902: 1887: 1868: 1556: 1552: 1544: 1528: 1524: 1516: 1505: 1495: 1491: 1298:surface area 1172: 1168: 1165: 1158: 1151: 1142: 1135: 1125: 1119: 1114: 1110: 1102: 1098: 1090: 1086: 1071: 913: 780:equation in 775: 770:aspect ratio 768: 738: 715:minor radius 714: 692:major radius 691: 639: 446:parametrized 443: 425: 421: 406:: horn torus 402: 398: 379: 375: 343: 342: 333:Klein bottle 329: 318: 223:homeomorphic 216: 195: 181: 179: 164: 157: 149: 145: 139: 135: 127: 123: 117: 112: 108: 88: 84: 76: 70: 36: 6520:Compactness 6305:Brady Haran 6209:Science4All 5831:16 November 5267:(16,32;3,3) 4549:genus three 4013:defined by 3403:duocylinder 2849:unit circle 2774:modulo the 2448:cross-ratio 2400:closed path 2235:unit square 2051:Hopf bundle 2029:. In fact, 1959:introducing 1499:and radius 916:square root 196:solid torus 183:solid torus 171:inner tubes 53:degenerates 28:Solid torus 6571:Operations 6553:components 6549:Number of 6529:smoothness 6508:Properties 6456:Semisphere 6371:Orientable 6267:"4D torus" 6214:1 November 5908:: 638–648. 5872:"poloidal" 5749:Xu, Dianna 5731:References 5645:Torus knot 5615:Toric lens 4805:cohomology 4658:April 2010 4629:immersions 4577:6 × 4 = 24 4489:two-sphere 3772:embedded ( 3384:flat torus 3362:Flat torus 3113:See also: 2931:invertible 2745:-torus is 2494:hypertorus 2416:isomorphic 2410:The first 2035:filled out 1570:), yields 1304:, giving: 739:The ratio 167:swim rings 136:horn torus 128:ring torus 6598:Immersion 6593:cross-cap 6591:Gluing a 6585:Gluing a 6482:Cross-cap 6427:(genus 2) 6411:genus 1; 6386:(genus 1) 6380:(genus 0) 6239:MathWorld 5984:CiteSeerX 5882:10 August 5856:MathWorld 5390:− 5355:− 5187:χ 5107:→ 5086:⁡ 5073:→ 5052:⁡ 5046:→ 5025:⁡ 5012:→ 4965:Thus the 4916:⁡ 4889:⁡ 4862:π 4855:⁡ 4828:⁡ 4807:algebra: 4697:⁡ 4587:Polyhedra 4538:genus two 4519:connected 4077:∣ 4062:∈ 4003:congruent 3953:) = (cos( 3911:⁡ 3896:⁡ 3884:⁡ 3860:⁡ 3848:⁡ 3776:of class 3766:isometric 3731:⁡ 3716:⁡ 3701:⁡ 3686:⁡ 3338:, with a 3260:unordered 3070:over the 2888:manifolds 2845:Lie group 2820:hypercube 2580:⏟ 2564:× 2561:⋯ 2558:× 2375:× 2367:≅ 2340:π 2336:× 2309:π 2278:π 2193:∼ 2169:∼ 1911:devices. 1835:− 1805:π 1767:− 1721:π 1691:− 1661:π 1641:− 1596:π 1452:π 1434:π 1408:π 1371:π 1353:π 1334:π 1223:− 985:− 852:− 672:π 657:∈ 654:φ 648:θ 622:θ 619:⁡ 600:φ 594:θ 580:φ 576:⁡ 567:θ 564:⁡ 536:φ 530:θ 516:φ 512:⁡ 503:θ 500:⁡ 472:φ 466:θ 339:Etymology 279:embedding 251:× 208:doughnuts 204:lifebuoys 6623:Surfaces 6617:Category 6551:boundary 6470:Cylinder 6287:and the 6130:Archived 6099:Archived 6095:22523238 6018:Archived 6006:16825563 5825:Archived 5799:Archived 5751:(2013). 5502:See also 5229:for the 4793:homology 4789:homotopy 4620:, where 4478:2-sphere 4445:surfaces 4190:, where 4007:boundary 3990:, where 3985:3-sphere 3791:it into 3446:, where 3411:quotient 3378:Seen in 3264:orbifold 3130:orbifold 2988:of rank 2936:of size 2872:subgroup 2838:manifold 2683:-torus, 2438:. Every 2137:quotient 2020:3-sphere 1915:Topology 1178:interior 918:gives a 778:implicit 352:Geometry 321:topology 219:topology 198:include 113:doughnut 105:coplanar 73:geometry 6501:notions 6499:Related 6465:Annulus 6461:Ribbon 6319:24 July 6301:(video) 6188:21 July 6162:21 July 6136:21 July 6105:21 July 6086:3358891 6014:2877171 5976:Bibcode 5967:Science 5942:27 July 5933:"Torus" 5851:"Torus" 5821:"Torus" 5805:21 July 5781:3026641 5525:3-torus 5493:in the 5490:A003600 4616:= 2 − 2 4516:compact 4439:surface 4429:surface 4404:in the 4343:fractal 3957:), sin( 3789:Mapping 3382:, a 4D 3181:As the 3174:(G♭-B♭) 3170:(F♯-A♯) 3158:Tonnetz 3062:,  3018:of the 2884:protori 2842:abelian 2835:compact 2780:lattice 2424:abelian 2139:of the 2002:circles 2000:of two 1998:product 1955:improve 1567:⁠ 1549:⁠ 1539:⁠ 1521:⁠ 1286:product 314:4-space 231:circles 229:of two 225:to the 206:, ring 200:O-rings 132:tangent 118:If the 91:) is a 89:toruses 6587:handle 6378:Sphere 6093:  6083:  6012:  6004:  5986:  5779:  5769:  5714:  5706:  5691:  5674:  5630:Toroid 5600:Sphere 5298:matrix 5285:is an 5141:has a 4682:. Its 4435:Genus 4425:Genus 4119:  3781:, 2 ≤ 3774:smooth 3752:where 3076:module 3026:. The 3009:choose 3000:of an 2992:. The 2980:of an 2776:action 2490:-torus 2473:-plane 1294:volume 1176:, the 212:bagels 210:, and 192:volume 159:toroid 154:sphere 97:circle 57:sphere 21:Taurus 6557:Genus 6384:Torus 6021:(PDF) 6010:S2CID 5962:(PDF) 5902:(PDF) 5662:Notes 5287:array 5231:plane 5049:Homeo 5016:Homeo 4582:faces 4575:with 4480:with 4449:genus 4394:three 3975:< 3963:then 3615:) ~ ( 3611:+ 1, 3607:) ~ ( 3396:{4,4} 3340:twist 2091:, is 2060:from 2049:(the 2045:over 2041:as a 1940:, or 1288:of a 1166:When 1149:When 1133:When 1127:apple 1121:lemon 1113:< 1089:> 1084:When 424:< 378:> 345:Torus 327:one. 325:genus 109:donut 77:torus 6452:Disk 6321:2019 6216:2022 6190:2012 6164:2012 6138:2012 6107:2012 6091:PMID 6002:PMID 5944:2021 5884:2007 5833:2014 5807:2012 5767:ISBN 5712:ISBN 5704:ISBN 5689:ISBN 5672:ISBN 5495:OEIS 5293:-by- 4791:and 4674:The 4510:The 4503:and 3939:and 3756:and 3623:+ 1) 3322:For 3155:The 2996:-th 2976:The 2258:The 1881:and 1542:and 1258:< 1076:and 806:axis 448:as: 188:disk 173:and 144:(or 85:tori 75:, a 6527:or 6491:... 6260:at 6081:PMC 6071:doi 6067:109 5994:doi 5972:313 5759:doi 5277:In 5262:STL 5233:.) 5081:TOP 5077:MCG 4886:Aut 4852:Aut 4819:MCG 4653:. 4463:of 3935:If 3908:cos 3893:sin 3881:sin 3857:cos 3845:sin 3785:≤ ∞ 3728:sin 3713:cos 3698:sin 3683:cos 3517:= 3413:, 3398:1,0 3315:on 3197:of 2896:of 2825:An 2492:or 2426:). 2242:ABA 2053:). 2033:is 1154:= 0 1138:= 0 808:is 776:An 616:sin 573:sin 561:cos 509:cos 497:cos 335:). 281:of 233:: 217:In 177:. 148:or 111:or 99:in 87:or 81:pl. 71:In 6619:: 6303:. 6291:: 6236:. 6207:. 6128:. 6124:. 6097:. 6089:. 6079:. 6065:. 6061:. 6038:. 6016:. 6008:. 6000:. 5992:. 5982:. 5970:. 5964:. 5935:. 5904:. 5874:. 5853:. 5777:MR 5775:. 5765:. 5747:; 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Index

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
homeomorphic

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