Knowledge (XXG)

Homotopy

Source 📝

5875: 5658: 5896: 5864: 3881: 5933: 5906: 5886: 3872: 2095: 1693: 4101:
of a one-dimensional space, the "loop of string" (or the circle), into this space, and this embedding gives a homeomorphism between the circle and its image in the embedding space. The intuitive idea behind the notion of knot equivalence is that one can
3165: 2601: 1845: 2982: 2415: 1757: 1340: 1435: 2872: 2451: 2739: 1163: 1982: 1555: 3058: 2270:
A solid disk is homotopy-equivalent to a single point, since you can deform the disk along radial lines continuously to a single point. However, they are not homeomorphic, since there is no
2359: 1977: 1550: 1966: 1905: 1473: 1221: 1279: 2676: 754: 2904: 4592: 4427: 2507: 2318: 4667: 4543: 2218:
are homotopy equivalent if they can be transformed into one another by bending, shrinking and expanding operations. Spaces that are homotopy-equivalent to a point are called
869: 328: 3014: 593: 3957:
Requiring that two embeddings be isotopic is a stronger requirement than that they be homotopic. For example, the map from the interval into the real numbers defined by
2779: 444: 394: 5093: 554: 4163:
Similar language is used for the equivalent concept in contexts where one has a stronger notion of equivalence. For example, a path between two smooth embeddings is a
1531: 905: 792: 697: 664: 5043: 4484: 3063: 470: 4619: 3426: 3376: 2806: 2631: 2478: 631: 4700: 3242: 5936: 3509: 3489: 3466: 3446: 3396: 3346: 3322: 3298: 3262: 3211: 3188: 2512: 812: 5001: 4730:
is the category whose objects are topological spaces, and whose morphisms are homotopy equivalence classes of continuous maps. Two topological spaces
4079:—the idea of isotopy is used to construct equivalence relations. For example, when should two knots be considered the same? We take two knots, 4373:, which characterizes the extension of a homotopy between two functions from a subset of some set to the set itself. It is useful when dealing with 5967: 2281:
and an untwisted (closed) strip are homotopy equivalent, since you can deform both strips continuously to a circle. But they are not homeomorphic.
3897:
since one cannot be deformed into the other through a continuous path of homeomorphisms of the ambient space. Thus they are not ambient-isotopic.
5539: 5484: 5292: 1774: 4195:(CTC) on a Lorentzian manifold is timelike homotopic to a point (that is, null timelike homotopic); such a manifold is therefore said to be 235: 4028:
Two homeomorphisms (which are special cases of embeddings) of the unit ball which agree on the boundary can be shown to be isotopic using
2918: 5570: 278: 38: 5924: 5919: 5448: 5327: 5264: 3989:
to the identity would have to exchange the endpoints, which would mean that they would have to 'pass through' each other. Moreover,
2364: 187: 136: 4132:, studied in this context, is an isotopy of the larger space, considered in light of its action on the embedded submanifold. Knots 954:
is some continuous function that takes the torus to the embedded surface-of-a-coffee-mug shape. The animation shows the image of
1702: 5914: 2808:
homotopy equivalent to a point has homotopy equivalent total and base spaces. This generalizes the previous two examples since
1284: 3684: 1345: 259: 58: 2811: 2420: 5816: 5522: 5504: 4742:
on the category of topological spaces is homotopy invariant if it can be expressed as a functor on the homotopy category.
2684: 1119: 2266:. Therefore, if X and Y are homeomorphic then they are homotopy-equivalent, but the opposite is not true. Some examples: 3680: 214:
In practice, there are technical difficulties in using homotopies with certain spaces. Algebraic topologists work with
5008: 4128:
embedding, with all intermediate values corresponding to embeddings. This corresponds to the definition of isotopy. An
3019: 5517: 5499: 4370: 4208: 4191:
is a homotopy such that the curve remains timelike during the continuous transformation from one curve to another. No
2090:{\displaystyle {\begin{aligned}H:B^{n}\times &\longrightarrow B^{n}\\(x,t)&\longmapsto (1-t)x.\end{aligned}}} 1688:{\displaystyle {\begin{aligned}H:\times &\longrightarrow C\\(s,t)&\longmapsto (1-t)f(s)+tg(s).\end{aligned}}} 5962: 5824: 5120: 223: 2323: 4672:
We can define the action of one equivalence class on another, and so we get a group. These groups are called the
4225: 3214: 1913: 1850: 1443: 215: 1168: 5957: 5895: 5623: 4926: 1226: 507:. We can also think of the second parameter as a "slider control" that allows us to smoothly transition from 5909: 2640: 204: 5512: 705: 5844: 5839: 5765: 5642: 5630: 5603: 5563: 5141: 4933: 4922: 4914: 3568: 3268: 2877: 70: 5686: 5613: 4937: 4918: 4192: 3823: 971:
varies with time from 0 to 1 over each cycle of the animation loop. It pauses, then shows the image as
5874: 4548: 4394: 2483: 2294: 250:: as "the surface of a doughnut" and as "the surface of a coffee mug". This is also an example of an 45:
shown above are homotopic relative to their endpoints. The animation represents one possible homotopy.
5834: 5786: 5760: 5608: 5395: 5131: 4624: 4500: 4029: 1969: 1016: 1004: 817: 283: 3923:, one can ask whether they can be connected 'through embeddings'. This gives rise to the concept of 5885: 5681: 5136: 5100: 5050: 4910: 4495: 4176: 3839: 4183:(representing something that only goes forwards, not backwards, in time, in every local frame). A 3997:
has not, which is impossible under an isotopy. However, the maps are homotopic; one homotopy from
2987: 950:
that takes the torus to the embedded surface-of-a-doughnut shape with which the animation starts;
559: 5879: 5829: 5750: 5740: 5618: 5598: 5419: 5385: 5288: 5104: 4766: 4313: 4196: 4072: 3520: 2752: 1768: 399: 349: 208: 93:"place") if one can be "continuously deformed" into the other, such a deformation being called a 5849: 5056: 4948:
into an appropriate fixed space, up to homotopy equivalence. For example, for any abelian group
521: 3160:{\displaystyle \mathbb {R} ^{k}\times (\mathbb {R} ^{n-k}-\{0\})\to (\mathbb {R} ^{n-k}-\{0\})} 1486: 5867: 5733: 5691: 5556: 5535: 5494: 5480: 5454: 5444: 5411: 5352: 5333: 5323: 5270: 5260: 4906: 4726: 4715: 4703: 4487: 4430: 4184: 3701: 3679:
An example of an algebraic invariant of topological spaces which is not homotopy-invariant is
3599: 3584: 2169: 2128: 1908: 1760: 874: 759: 700: 200: 62: 669: 636: 5647: 5593: 5403: 5146: 5013: 4444: 4204: 3572: 3557: 449: 331: 148: 100: 31: 4597: 3404: 3354: 2784: 2609: 2456: 598: 5706: 5701: 4721: 4129: 3951: 3543: 2596:{\displaystyle H(t,\cdot )=t\cdot p_{0}+(1-t)\cdot \operatorname {id} _{\mathbb {R} ^{n}}} 1534: 1480: 196: 42: 4679: 4106:
one embedding to another through a path of embeddings: a continuous function starting at
3219: 2278: 5399: 5796: 5728: 4854: 4778: 4673: 4386: 4188: 3611: 3494: 3474: 3451: 3431: 3381: 3331: 3307: 3283: 3247: 3196: 3173: 910:
The animation that is looped above right provides an example of a homotopy between two
797: 4959: 4429:
being homotopic relative to a subspace is an equivalence relation, we can look at the
5951: 5806: 5716: 5696: 5423: 4834: 4738:
are isomorphic in this category if and only if they are homotopy-equivalent. Then a
2910: 2231: 339: 5899: 5791: 5711: 5657: 3894: 3708:. These are homotopies which keep the elements of the subspace fixed. Formally: if 3398:
is null-homotopic precisely when it can be continuously extended to a map from the
2747: 2219: 518:
An alternative notation is to say that a homotopy between two continuous functions
234: 17: 5889: 5801: 4374: 4076: 3880: 3511:
to itself—which is always a homotopy equivalence—is null-homotopic.
3349: 54: 3527:, that is, they respect the relation of homotopy equivalence. For example, if 5745: 5676: 5635: 5407: 5298: 5213: 5186: 3191: 1476: 219: 5415: 5355: 5165: 5770: 5458: 5360: 5337: 5274: 5126: 4363: 4098: 4094: 4033: 3920: 3399: 2271: 911: 476: 239: 195:) between the two functions. A notable use of homotopy is the definition of 37: 5237: 5755: 5672: 5579: 5438: 4200: 4180: 4061: 2634: 50: 5238:"algebraic topology - Path homotopy and separately continuous functions" 3871: 5303: 5191: 4739: 4146:
are considered equivalent when there is an ambient isotopy which moves
2274:
between them (since one is an infinite set, while the other is finite).
1840:{\displaystyle B^{n}:=\left\{x\in \mathbb {R} ^{n}:\|x\|\leq 1\right\}} 5390: 5376:
Monroe, Hunter (2008-11-01). "Are Causality Violations Undesirable?".
4917:
have been developed. The methods for algebraic equations include the
3890: 3729: 88: 77: 2361:. The part that needs to be checked is the existence of a homotopy 4545:
as a subspace, then the equivalence classes form a group, denoted
4160:. This is the appropriate definition in the topological category. 243: 233: 36: 2977:{\displaystyle \mathbb {R} ^{n}-\mathbb {R} ^{k}\simeq S^{n-k-1}} 5552: 3304:
if it is homotopic to a constant function. (The homotopy from
2913:
is a fiber bundle with a fiber homotopy equivalent to a point.
2410:{\displaystyle H:I\times \mathbb {R} ^{n}\to \mathbb {R} ^{n}} 178: 127: 4720:
The idea of homotopy can be turned into a formal category of
83: 991:
are said to be homotopic if and only if there is a homotopy
5548: 172: 163: 157: 121: 106: 1752:{\displaystyle \operatorname {id} _{B^{n}}:B^{n}\to B^{n}} 115: 4068:
are isotopic because they can be connected by rotations.
1335:{\displaystyle H:\mathbb {R} \times \to \mathbb {R} ^{2}} 975:
varies back from 1 to 0, pauses, and repeats this cycle.
3931:, in the notation used before, such that for each fixed 3614:. (Without the path-connectedness assumption, one has π 1430:{\displaystyle H(x,t)=\left(x,(1-t)x^{3}+te^{x}\right)} 27:
Continuous deformation between two continuous functions
5259:. Cambridge: Cambridge University Press. p. 185. 4925:). The methods for differential equations include the 4362:
The homotopy lifting property is used to characterize
2867:{\displaystyle \pi :\mathbb {R} ^{n}-\{0\}\to S^{n-1}} 2446:{\displaystyle \operatorname {id} _{\mathbb {R} ^{n}}} 2234:
is a special case of a homotopy equivalence, in which
5322:. Cambridge: Cambridge University Press. p. 11. 5059: 5016: 4962: 4682: 4627: 4600: 4551: 4503: 4447: 4397: 3497: 3491:
is contractible if and only if the identity map from
3477: 3454: 3434: 3407: 3384: 3357: 3334: 3310: 3286: 3250: 3222: 3199: 3176: 3066: 3022: 2990: 2921: 2880: 2814: 2787: 2755: 2687: 2643: 2612: 2515: 2486: 2459: 2423: 2367: 2326: 2297: 1980: 1916: 1853: 1777: 1705: 1553: 1489: 1446: 1348: 1287: 1229: 1171: 1122: 877: 820: 800: 762: 708: 672: 639: 601: 562: 524: 452: 402: 352: 286: 188: 166: 137: 4845:
is pointed, then the group homomorphisms induced by
2734:{\displaystyle \mathbb {R} ^{n}-\{0\}\simeq S^{n-1}} 1158:{\displaystyle f,g:\mathbb {R} \to \mathbb {R} ^{2}} 175: 169: 124: 118: 5815: 5779: 5665: 5586: 3687:, and compactification is not homotopy-invariant). 160: 154: 151: 112: 109: 103: 30:This article is about topology. For chemistry, see 5087: 5037: 4995: 4694: 4661: 4613: 4586: 4537: 4478: 4421: 4369:Another useful property involving homotopy is the 3503: 3483: 3460: 3440: 3420: 3390: 3370: 3340: 3324:to a constant function is then sometimes called a 3316: 3292: 3256: 3236: 3205: 3182: 3159: 3052: 3008: 2976: 2898: 2866: 2800: 2773: 2733: 2670: 2625: 2595: 2501: 2472: 2445: 2409: 2353: 2312: 2089: 1960: 1899: 1839: 1751: 1687: 1525: 1467: 1429: 1334: 1273: 1215: 1157: 899: 863: 806: 786: 748: 691: 658: 625: 587: 548: 464: 438: 388: 322: 3683:(which is, roughly speaking, the homology of the 3053:{\displaystyle \mathbb {R} ^{n}-\mathbb {R} ^{k}} 1972:. Then the following is a homotopy between them: 515:as the slider moves from 0 to 1, and vice versa. 5187:"Homotopy Type Theory Discussed - Computerphile" 4932:Homotopy theory can be used as a foundation for 4005::  ×  →  given by 3993:has changed the orientation of the interval and 3167:, then applying the homotopy equivalences above. 4064:around the origin, and so the identity map and 3838:is the identity map, this is known as a strong 3471:It follows from these definitions that a space 2291:The first example of a homotopy equivalence is 5440:Introduction to numerical continuation methods 946:is some continuous function from the torus to 5564: 5107:for singular cohomology with coefficients in 5003:of based homotopy classes of based maps from 3950:A related, but different, concept is that of 3519:Homotopy equivalence is important because in 1015:. This homotopy relation is compatible with 8: 5123:(relative version of a homotopy equivalence) 3151: 3145: 3112: 3106: 2842: 2836: 2709: 2703: 2665: 2659: 2354:{\displaystyle \mathbb {R} ^{n}\simeq \{0\}} 2348: 2342: 1823: 1817: 1007:on the set of all continuous functions from 4199:by timelike curves. A manifold such as the 1961:{\displaystyle c_{\vec {0}}(x):={\vec {0}}} 1900:{\displaystyle c_{\vec {0}}:B^{n}\to B^{n}} 1468:{\displaystyle C\subseteq \mathbb {R} ^{n}} 871:. It is not sufficient to require each map 5932: 5905: 5571: 5557: 5549: 2509:onto the origin. This can be described as 1216:{\displaystyle f(x):=\left(x,x^{3}\right)} 1003:as described above. Being homotopic is an 5389: 5064: 5058: 5015: 4961: 4681: 4650: 4626: 4605: 4599: 4575: 4556: 4550: 4526: 4502: 4470: 4446: 4396: 3496: 3476: 3453: 3433: 3412: 3406: 3383: 3362: 3356: 3333: 3309: 3285: 3249: 3226: 3221: 3198: 3175: 3130: 3126: 3125: 3091: 3087: 3086: 3073: 3069: 3068: 3065: 3044: 3040: 3039: 3029: 3025: 3024: 3021: 2989: 2956: 2943: 2939: 2938: 2928: 2924: 2923: 2920: 2887: 2883: 2882: 2879: 2852: 2827: 2823: 2822: 2813: 2792: 2786: 2754: 2719: 2694: 2690: 2689: 2686: 2650: 2646: 2645: 2642: 2617: 2611: 2585: 2581: 2580: 2578: 2547: 2514: 2493: 2489: 2488: 2485: 2464: 2458: 2435: 2431: 2430: 2428: 2422: 2401: 2397: 2396: 2386: 2382: 2381: 2366: 2333: 2329: 2328: 2325: 2304: 2300: 2299: 2296: 2030: 1995: 1981: 1979: 1947: 1946: 1922: 1921: 1915: 1891: 1878: 1859: 1858: 1852: 1808: 1804: 1803: 1782: 1776: 1743: 1730: 1715: 1710: 1704: 1554: 1552: 1537:with the same endpoints, then there is a 1488: 1459: 1455: 1454: 1445: 1416: 1400: 1347: 1326: 1322: 1321: 1295: 1294: 1286: 1274:{\displaystyle g(x)=\left(x,e^{x}\right)} 1260: 1228: 1202: 1170: 1149: 1145: 1144: 1136: 1135: 1121: 882: 876: 825: 819: 799: 761: 731: 707: 677: 671: 644: 638: 600: 567: 561: 523: 451: 401: 351: 285: 4921:method and the continuation method (see 2606:There is a homotopy equivalence between 5157: 4749:homotopy invariant: this means that if 3060:as the total space of the fiber bundle 1067:are homotopic, then their compositions 814:. The two versions coincide by setting 4905:Based on the concept of the homotopy, 4179:, certain curves are distinguished as 3610:are isomorphic, and so are the higher 3535:are homotopy equivalent spaces, then: 2671:{\displaystyle \mathbb {R} ^{2}-\{0\}} 2226:Homotopy equivalence vs. homeomorphism 5103:of Eilenberg-MacLane spaces are 749:{\displaystyle (x,t)\mapsto h_{t}(x)} 7: 4391:Since the relation of two functions 3903:When two given continuous functions 2899:{\displaystyle \mathbb {R} _{>0}} 556:is a family of continuous functions 5166:"Homotopy Definition & Meaning" 4745:For example, homology groups are a 4207:(by any type of curve), and yet be 963:(X) as a function of the parameter 503:and at time 1 we have the function 5443:. Kurt Georg. Philadelphia: SIAM. 4628: 4504: 4032:. For this reason, the map of the 25: 5045:is in natural bijection with the 4587:{\displaystyle \pi _{n}(Y,y_{0})} 499:: at time 0 we have the function 258:Formally, a homotopy between two 5931: 5904: 5894: 5884: 5873: 5863: 5862: 5656: 5530:Spanier, Edwin (December 1994). 4940:a cohomology functor on a space 4621:is in the image of the subspace 4422:{\displaystyle f,g\colon X\to Y} 4220:Lifting and extension properties 3879: 3870: 2502:{\displaystyle \mathbb {R} ^{n}} 2313:{\displaystyle \mathbb {R} ^{n}} 2250:(not only homotopic to it), and 147: 99: 5299:"History of algebraic topology" 4662:{\displaystyle \partial (^{n})} 4538:{\displaystyle \partial (^{n})} 3706:homotopy relative to a subspace 2244:is equal to the identity map id 1968:which sends every point to the 864:{\displaystyle h_{t}(x)=H(x,t)} 323:{\displaystyle H:X\times \to Y} 5968:Theory of continuous functions 5082: 5070: 5032: 5020: 4990: 4987: 4975: 4963: 4656: 4647: 4634: 4631: 4581: 4562: 4532: 4523: 4510: 4507: 4467: 4454: 4413: 4060:) is isotopic to a 180-degree 3662:is a homotopy equivalence and 3154: 3121: 3118: 3115: 3082: 2845: 2765: 2568: 2556: 2531: 2519: 2392: 2194:. If such a pair exists, then 2074: 2062: 2059: 2052: 2040: 2023: 2016: 2004: 1952: 1940: 1934: 1927: 1884: 1864: 1736: 1675: 1669: 1657: 1651: 1645: 1633: 1630: 1623: 1611: 1601: 1594: 1582: 1576: 1564: 1517: 1514: 1502: 1393: 1381: 1364: 1352: 1317: 1314: 1302: 1239: 1233: 1181: 1175: 1140: 894: 888: 858: 846: 837: 831: 781: 769: 743: 737: 724: 721: 709: 620: 608: 579: 540: 433: 427: 418: 406: 383: 377: 368: 356: 314: 311: 299: 1: 3598:are path-connected, then the 2874:is a fiber bundle with fiber 2107:Given two topological spaces 3681:compactly supported homology 3009:{\displaystyle 0\leq k<n} 588:{\displaystyle h_{t}:X\to Y} 251: 89: 78: 5518:Encyclopedia of Mathematics 5500:Encyclopedia of Mathematics 4952:, and any based CW-complex 4837:, and the homotopy between 4371:homotopy extension property 4209:timelike multiply connected 4121: = 1 giving the 3911:from the topological space 3748:if there exists a homotopy 2774:{\displaystyle \pi :E\to B} 1437:is a homotopy between them. 1019:in the following sense: if 439:{\displaystyle H(x,1)=g(x)} 389:{\displaystyle H(x,0)=f(x)} 5984: 5825:Banach fixed-point theorem 5242:Mathematics Stack Exchange 5121:Fiber-homotopy equivalence 5088:{\displaystyle H^{n}(X,G)} 4713: 4384: 4223: 4110: = 0 giving the 3744:are homotopic relative to 3704:, one needs the notion of 3271:is a homotopy equivalence. 3244:is homotopy equivalent to 3213:is contractible, then the 2210:. Intuitively, two spaces 549:{\displaystyle f,g:X\to Y} 475:If we think of the second 269:from a topological space 216:compactly generated spaces 84: 74: 29: 5858: 5654: 5408:10.1007/s10701-008-9254-9 4226:Homotopy lifting property 3973:isotopic to the identity 3915:to the topological space 3893:is not equivalent to the 3716:are continuous maps from 1526:{\displaystyle f,g:\to C} 5475:Armstrong, M.A. (1979). 5437:Allgower, E. L. (2003). 5318:Allen., Hatcher (2002). 5255:Allen., Hatcher (2002). 5214:"Homotopy | mathematics" 4927:homotopy analysis method 4765:are homotopic, then the 4702:, it is also called the 4433:of maps between a fixed 4323:), then we can lift all 2127:is a pair of continuous 900:{\displaystyle h_{t}(x)} 787:{\displaystyle X\times } 5513:"Isotopy (in topology)" 5218:Encyclopedia Britannica 5009:Eilenberg–MacLane space 4494:times, and we take its 4260:and we are given a map 3927:, which is a homotopy, 3700:In order to define the 3328:.) For example, a map 692:{\displaystyle h_{1}=g} 659:{\displaystyle h_{0}=f} 273:to a topological space 238:A homotopy between two 5880:Mathematics portal 5780:Metrics and properties 5766:Second-countable space 5378:Foundations of Physics 5297:Albin, Pierre (2019). 5089: 5039: 5038:{\displaystyle K(G,n)} 4997: 4923:numerical continuation 4915:differential equations 4696: 4663: 4615: 4588: 4539: 4480: 4479:{\displaystyle X=^{n}} 4423: 4230:If we have a homotopy 4075:—for example in 3947:) gives an embedding. 3505: 3485: 3462: 3442: 3422: 3392: 3372: 3342: 3318: 3294: 3269:deformation retraction 3258: 3238: 3207: 3184: 3161: 3054: 3010: 2978: 2900: 2868: 2802: 2775: 2735: 2672: 2627: 2597: 2503: 2474: 2447: 2411: 2355: 2320:with a point, denoted 2314: 2091: 1962: 1901: 1841: 1753: 1689: 1543:straight-line homotopy 1527: 1469: 1431: 1336: 1275: 1217: 1159: 901: 865: 808: 788: 750: 693: 660: 627: 589: 550: 489:continuous deformation 466: 465:{\displaystyle x\in X} 440: 390: 324: 255: 65:to another are called 46: 5090: 5040: 4998: 4919:homotopy continuation 4697: 4664: 4616: 4614:{\displaystyle y_{0}} 4589: 4540: 4486:, the unit interval 4481: 4424: 4193:closed timelike curve 4117:embedding, ending at 3985:. Any homotopy from 3854:is a point, the term 3506: 3486: 3463: 3443: 3423: 3421:{\displaystyle D^{2}} 3393: 3373: 3371:{\displaystyle S^{1}} 3343: 3319: 3295: 3259: 3239: 3208: 3185: 3162: 3055: 3011: 2979: 2901: 2869: 2803: 2801:{\displaystyle F_{b}} 2776: 2736: 2673: 2628: 2626:{\displaystyle S^{1}} 2598: 2504: 2475: 2473:{\displaystyle p_{0}} 2448: 2412: 2356: 2315: 2092: 1963: 1902: 1842: 1754: 1690: 1528: 1470: 1432: 1337: 1276: 1218: 1160: 983:Continuous functions 902: 866: 809: 789: 751: 694: 661: 628: 626:{\displaystyle t\in } 590: 551: 467: 441: 391: 325: 237: 40: 5835:Invariance of domain 5787:Euler characteristic 5761:Bundle (mathematics) 5132:Homotopy type theory 5099:. One says that the 5057: 5014: 4960: 4857:are also the same: π 4680: 4625: 4598: 4549: 4501: 4445: 4395: 4097:space. A knot is an 3495: 3475: 3452: 3432: 3405: 3382: 3355: 3332: 3308: 3284: 3248: 3220: 3197: 3174: 3064: 3020: 2988: 2919: 2878: 2812: 2785: 2753: 2685: 2641: 2610: 2513: 2484: 2480:, the projection of 2457: 2421: 2365: 2324: 2295: 2168:is homotopic to the 2117:homotopy equivalence 2103:Homotopy equivalence 1978: 1914: 1851: 1775: 1703: 1551: 1487: 1444: 1346: 1285: 1227: 1169: 1120: 1107:are also homotopic. 1017:function composition 1005:equivalence relation 922:, of the torus into 875: 818: 798: 760: 706: 670: 637: 599: 560: 522: 450: 400: 350: 284: 260:continuous functions 82:"same, similar" and 59:continuous functions 5845:Tychonoff's theorem 5840:Poincaré conjecture 5594:General (point-set) 5400:2008FoPh...38.1065M 5142:Poincaré conjecture 5137:Mapping class group 5105:representing spaces 5095: of the space 5051:singular cohomology 4907:computation methods 4767:group homomorphisms 4695:{\displaystyle n=1} 4431:equivalence classes 4177:Lorentzian manifold 4001:to the identity is 3840:deformation retract 3736:, then we say that 3237:{\displaystyle X/A} 2204:homotopy equivalent 1440:More generally, if 1043:are homotopic, and 756:is continuous from 279:continuous function 277:is defined to be a 5830:De Rham cohomology 5751:Polyhedral complex 5741:Simplicial complex 5532:Algebraic Topology 5353:Weisstein, Eric W. 5320:Algebraic topology 5257:Algebraic topology 5085: 5035: 4993: 4692: 4659: 4611: 4584: 4535: 4476: 4419: 4197:multiply connected 4073:geometric topology 3600:fundamental groups 3525:homotopy invariant 3523:many concepts are 3521:algebraic topology 3501: 3481: 3458: 3438: 3418: 3388: 3368: 3338: 3314: 3290: 3254: 3234: 3203: 3180: 3157: 3050: 3006: 2974: 2896: 2864: 2798: 2771: 2731: 2668: 2623: 2593: 2499: 2470: 2443: 2407: 2351: 2310: 2188:is homotopic to id 2087: 2085: 1958: 1897: 1837: 1749: 1685: 1683: 1523: 1465: 1427: 1332: 1271: 1213: 1155: 907:to be continuous. 897: 861: 804: 784: 746: 689: 656: 623: 585: 546: 462: 436: 386: 320: 256: 209:algebraic topology 47: 5963:Maps of manifolds 5945: 5944: 5734:fundamental group 5541:978-0-387-94426-5 5486:978-0-387-90839-7 5384:(11): 1065–1069. 4727:homotopy category 4716:Homotopy category 4710:Homotopy category 4704:fundamental group 4185:timelike homotopy 4171:Timelike homotopy 4030:Alexander's trick 3702:fundamental group 3696:Relative homotopy 3629:) isomorphic to π 3573:cohomology groups 3504:{\displaystyle X} 3484:{\displaystyle X} 3468:on the boundary. 3461:{\displaystyle f} 3448:that agrees with 3441:{\displaystyle X} 3391:{\displaystyle X} 3341:{\displaystyle f} 3317:{\displaystyle f} 3293:{\displaystyle f} 3257:{\displaystyle X} 3206:{\displaystyle X} 3183:{\displaystyle A} 2206:, or of the same 1955: 1930: 1909:constant function 1867: 1761:identity function 807:{\displaystyle Y} 230:Formal definition 201:cohomotopy groups 63:topological space 18:Relative homotopy 16:(Redirected from 5975: 5935: 5934: 5908: 5907: 5898: 5888: 5878: 5877: 5866: 5865: 5660: 5573: 5566: 5559: 5550: 5545: 5526: 5508: 5490: 5463: 5462: 5434: 5428: 5427: 5393: 5373: 5367: 5366: 5365: 5348: 5342: 5341: 5315: 5309: 5308: 5285: 5279: 5278: 5252: 5246: 5245: 5234: 5228: 5227: 5225: 5224: 5210: 5204: 5203: 5201: 5199: 5183: 5177: 5176: 5174: 5172: 5162: 5147:Regular homotopy 5094: 5092: 5091: 5086: 5069: 5068: 5044: 5042: 5041: 5036: 5002: 5000: 4999: 4996:{\displaystyle } 4994: 4853:on the level of 4833:are in addition 4825:. Likewise, if 4777:on the level of 4701: 4699: 4698: 4693: 4668: 4666: 4665: 4660: 4655: 4654: 4620: 4618: 4617: 4612: 4610: 4609: 4593: 4591: 4590: 4585: 4580: 4579: 4561: 4560: 4544: 4542: 4541: 4536: 4531: 4530: 4485: 4483: 4482: 4477: 4475: 4474: 4428: 4426: 4425: 4420: 4361: 4355: 4344: 4343: 4338:× → 4333: 4308: 4302: 4298: 4280: 4279: 4266: 4259: 4254: 4243: 4239:× → 4205:simply connected 3883: 3874: 3856:pointed homotopy 3817: 3810: 3800: 3761: 3685:compactification 3675: 3661: 3558:simply connected 3510: 3508: 3507: 3502: 3490: 3488: 3487: 3482: 3467: 3465: 3464: 3459: 3447: 3445: 3444: 3439: 3427: 3425: 3424: 3419: 3417: 3416: 3397: 3395: 3394: 3389: 3377: 3375: 3374: 3369: 3367: 3366: 3347: 3345: 3344: 3339: 3323: 3321: 3320: 3315: 3299: 3297: 3296: 3291: 3263: 3261: 3260: 3255: 3243: 3241: 3240: 3235: 3230: 3212: 3210: 3209: 3204: 3189: 3187: 3186: 3181: 3170:If a subcomplex 3166: 3164: 3163: 3158: 3141: 3140: 3129: 3102: 3101: 3090: 3078: 3077: 3072: 3059: 3057: 3056: 3051: 3049: 3048: 3043: 3034: 3033: 3028: 3015: 3013: 3012: 3007: 2983: 2981: 2980: 2975: 2973: 2972: 2948: 2947: 2942: 2933: 2932: 2927: 2905: 2903: 2902: 2897: 2895: 2894: 2886: 2873: 2871: 2870: 2865: 2863: 2862: 2832: 2831: 2826: 2807: 2805: 2804: 2799: 2797: 2796: 2780: 2778: 2777: 2772: 2740: 2738: 2737: 2732: 2730: 2729: 2699: 2698: 2693: 2681:More generally, 2677: 2675: 2674: 2669: 2655: 2654: 2649: 2632: 2630: 2629: 2624: 2622: 2621: 2602: 2600: 2599: 2594: 2592: 2591: 2590: 2589: 2584: 2552: 2551: 2508: 2506: 2505: 2500: 2498: 2497: 2492: 2479: 2477: 2476: 2471: 2469: 2468: 2452: 2450: 2449: 2444: 2442: 2441: 2440: 2439: 2434: 2416: 2414: 2413: 2408: 2406: 2405: 2400: 2391: 2390: 2385: 2360: 2358: 2357: 2352: 2338: 2337: 2332: 2319: 2317: 2316: 2311: 2309: 2308: 2303: 2259: 2243: 2187: 2167: 2157: 2143: 2096: 2094: 2093: 2088: 2086: 2035: 2034: 2000: 1999: 1967: 1965: 1964: 1959: 1957: 1956: 1948: 1933: 1932: 1931: 1923: 1906: 1904: 1903: 1898: 1896: 1895: 1883: 1882: 1870: 1869: 1868: 1860: 1846: 1844: 1843: 1838: 1836: 1832: 1813: 1812: 1807: 1787: 1786: 1758: 1756: 1755: 1750: 1748: 1747: 1735: 1734: 1722: 1721: 1720: 1719: 1694: 1692: 1691: 1686: 1684: 1532: 1530: 1529: 1524: 1474: 1472: 1471: 1466: 1464: 1463: 1458: 1436: 1434: 1433: 1428: 1426: 1422: 1421: 1420: 1405: 1404: 1341: 1339: 1338: 1333: 1331: 1330: 1325: 1298: 1280: 1278: 1277: 1272: 1270: 1266: 1265: 1264: 1222: 1220: 1219: 1214: 1212: 1208: 1207: 1206: 1164: 1162: 1161: 1156: 1154: 1153: 1148: 1139: 1106: 1082: 1066: 1042: 941: 927: 906: 904: 903: 898: 887: 886: 870: 868: 867: 862: 830: 829: 813: 811: 810: 805: 793: 791: 790: 785: 755: 753: 752: 747: 736: 735: 698: 696: 695: 690: 682: 681: 665: 663: 662: 657: 649: 648: 632: 630: 629: 624: 594: 592: 591: 586: 572: 571: 555: 553: 552: 547: 471: 469: 468: 463: 445: 443: 442: 437: 395: 393: 392: 387: 329: 327: 326: 321: 191: 185: 184: 181: 180: 177: 174: 171: 168: 165: 162: 159: 156: 153: 141: 134: 133: 130: 129: 126: 123: 120: 117: 114: 111: 108: 105: 92: 87: 86: 81: 76: 32:Homotopic groups 21: 5983: 5982: 5978: 5977: 5976: 5974: 5973: 5972: 5958:Homotopy theory 5948: 5947: 5946: 5941: 5872: 5854: 5850:Urysohn's lemma 5811: 5775: 5661: 5652: 5624:low-dimensional 5582: 5577: 5542: 5529: 5511: 5493: 5487: 5474: 5471: 5466: 5451: 5436: 5435: 5431: 5375: 5374: 5370: 5351: 5350: 5349: 5345: 5330: 5317: 5316: 5312: 5296: 5293:Wayback Machine 5286: 5282: 5267: 5254: 5253: 5249: 5236: 5235: 5231: 5222: 5220: 5212: 5211: 5207: 5197: 5195: 5185: 5184: 5180: 5170: 5168: 5164: 5163: 5159: 5155: 5117: 5060: 5055: 5054: 5012: 5011: 4958: 4957: 4944:by mappings of 4934:homology theory 4903: 4892: 4882: 4872: 4862: 4855:homotopy groups 4816: 4806: 4796: 4786: 4781:are the same: H 4779:homology groups 4722:category theory 4718: 4712: 4678: 4677: 4674:homotopy groups 4646: 4623: 4622: 4601: 4596: 4595: 4571: 4552: 4547: 4546: 4522: 4499: 4498: 4466: 4443: 4442: 4393: 4392: 4389: 4383: 4351: 4346: 4339: 4329: 4328: 4322: 4311: 4304: 4301: 4294: 4288: 4282: 4275: 4269: 4262: 4261: 4250: 4245: 4231: 4228: 4222: 4217: 4189:timelike curves 4173: 4159: 4152: 4145: 4138: 4130:ambient isotopy 4127: 4116: 4092: 4085: 4017:) = 2 3952:ambient isotopy 3901: 3900: 3899: 3898: 3886: 3885: 3884: 3876: 3875: 3864: 3812: 3802: 3771: 3749: 3698: 3693: 3669: 3663: 3649: 3647: 3632: 3628: 3617: 3612:homotopy groups 3567:The (singular) 3560:if and only if 3546:if and only if 3517: 3493: 3492: 3473: 3472: 3450: 3449: 3430: 3429: 3408: 3403: 3402: 3380: 3379: 3358: 3353: 3352: 3330: 3329: 3306: 3305: 3282: 3281: 3278: 3246: 3245: 3218: 3217: 3195: 3194: 3172: 3171: 3124: 3085: 3067: 3062: 3061: 3038: 3023: 3018: 3017: 2986: 2985: 2952: 2937: 2922: 2917: 2916: 2881: 2876: 2875: 2848: 2821: 2810: 2809: 2788: 2783: 2782: 2751: 2750: 2715: 2688: 2683: 2682: 2644: 2639: 2638: 2613: 2608: 2607: 2579: 2574: 2543: 2511: 2510: 2487: 2482: 2481: 2460: 2455: 2454: 2429: 2424: 2419: 2418: 2395: 2380: 2363: 2362: 2327: 2322: 2321: 2298: 2293: 2292: 2288: 2265: 2255: ∘  2251: 2249: 2239: ∘  2235: 2228: 2202:are said to be 2193: 2183: ∘  2179: 2177: 2163: ∘  2159: 2145: 2131: 2105: 2084: 2083: 2055: 2037: 2036: 2026: 2019: 1991: 1976: 1975: 1917: 1912: 1911: 1887: 1874: 1854: 1849: 1848: 1802: 1795: 1791: 1778: 1773: 1772: 1771:; i.e. the set 1739: 1726: 1711: 1706: 1701: 1700: 1682: 1681: 1626: 1608: 1607: 1597: 1549: 1548: 1539:linear homotopy 1485: 1484: 1481:Euclidean space 1453: 1442: 1441: 1412: 1396: 1374: 1370: 1344: 1343: 1320: 1283: 1282: 1281:, then the map 1256: 1249: 1245: 1225: 1224: 1198: 1191: 1187: 1167: 1166: 1143: 1118: 1117: 1113: 1097: 1091: ∘  1090: 1084: 1081: 1075: ∘  1074: 1068: 1057: 1050: 1044: 1033: 1026: 1020: 981: 962: 937: 923: 878: 873: 872: 821: 816: 815: 796: 795: 758: 757: 727: 704: 703: 673: 668: 667: 640: 635: 634: 597: 596: 563: 558: 557: 520: 519: 448: 447: 398: 397: 348: 347: 282: 281: 232: 197:homotopy groups 189: 150: 146: 139: 102: 98: 41:The two dashed 35: 28: 23: 22: 15: 12: 11: 5: 5981: 5979: 5971: 5970: 5965: 5960: 5950: 5949: 5943: 5942: 5940: 5939: 5929: 5928: 5927: 5922: 5917: 5902: 5892: 5882: 5870: 5859: 5856: 5855: 5853: 5852: 5847: 5842: 5837: 5832: 5827: 5821: 5819: 5813: 5812: 5810: 5809: 5804: 5799: 5797:Winding number 5794: 5789: 5783: 5781: 5777: 5776: 5774: 5773: 5768: 5763: 5758: 5753: 5748: 5743: 5738: 5737: 5736: 5731: 5729:homotopy group 5721: 5720: 5719: 5714: 5709: 5704: 5699: 5689: 5684: 5679: 5669: 5667: 5663: 5662: 5655: 5653: 5651: 5650: 5645: 5640: 5639: 5638: 5628: 5627: 5626: 5616: 5611: 5606: 5601: 5596: 5590: 5588: 5584: 5583: 5578: 5576: 5575: 5568: 5561: 5553: 5547: 5546: 5540: 5527: 5509: 5491: 5485: 5477:Basic Topology 5470: 5467: 5465: 5464: 5449: 5429: 5368: 5343: 5328: 5310: 5280: 5265: 5247: 5229: 5205: 5178: 5156: 5154: 5151: 5150: 5149: 5144: 5139: 5134: 5129: 5124: 5116: 5113: 5101:omega-spectrum 5084: 5081: 5078: 5075: 5072: 5067: 5063: 5034: 5031: 5028: 5025: 5022: 5019: 4992: 4989: 4986: 4983: 4980: 4977: 4974: 4971: 4968: 4965: 4902: 4899: 4888: 4878: 4868: 4858: 4835:path connected 4812: 4802: 4792: 4782: 4714:Main article: 4711: 4708: 4691: 4688: 4685: 4676:. In the case 4658: 4653: 4649: 4645: 4642: 4639: 4636: 4633: 4630: 4608: 4604: 4583: 4578: 4574: 4570: 4567: 4564: 4559: 4555: 4534: 4529: 4525: 4521: 4518: 4515: 4512: 4509: 4506: 4473: 4469: 4465: 4462: 4459: 4456: 4453: 4450: 4418: 4415: 4412: 4409: 4406: 4403: 4400: 4387:Homotopy group 4385:Main article: 4382: 4379: 4320: 4309: 4299: 4286: 4267: 4224:Main article: 4221: 4218: 4216: 4213: 4172: 4169: 4165:smooth isotopy 4157: 4150: 4143: 4136: 4125: 4114: 4090: 4083: 4056:, − 3888: 3887: 3878: 3877: 3869: 3868: 3867: 3866: 3865: 3863: 3860: 3697: 3694: 3692: 3689: 3677: 3676: 3667: 3645: 3630: 3626: 3615: 3588: 3565: 3551: 3544:path-connected 3516: 3513: 3500: 3480: 3457: 3437: 3415: 3411: 3387: 3365: 3361: 3337: 3313: 3302:null-homotopic 3300:is said to be 3289: 3277: 3274: 3273: 3272: 3265: 3253: 3233: 3229: 3225: 3215:quotient space 3202: 3179: 3168: 3156: 3153: 3150: 3147: 3144: 3139: 3136: 3133: 3128: 3123: 3120: 3117: 3114: 3111: 3108: 3105: 3100: 3097: 3094: 3089: 3084: 3081: 3076: 3071: 3047: 3042: 3037: 3032: 3027: 3005: 3002: 2999: 2996: 2993: 2971: 2968: 2965: 2962: 2959: 2955: 2951: 2946: 2941: 2936: 2931: 2926: 2914: 2907: 2893: 2890: 2885: 2861: 2858: 2855: 2851: 2847: 2844: 2841: 2838: 2835: 2830: 2825: 2820: 2817: 2795: 2791: 2770: 2767: 2764: 2761: 2758: 2744: 2743: 2742: 2728: 2725: 2722: 2718: 2714: 2711: 2708: 2705: 2702: 2697: 2692: 2667: 2664: 2661: 2658: 2653: 2648: 2620: 2616: 2604: 2588: 2583: 2577: 2573: 2570: 2567: 2564: 2561: 2558: 2555: 2550: 2546: 2542: 2539: 2536: 2533: 2530: 2527: 2524: 2521: 2518: 2496: 2491: 2467: 2463: 2438: 2433: 2427: 2404: 2399: 2394: 2389: 2384: 2379: 2376: 2373: 2370: 2350: 2347: 2344: 2341: 2336: 2331: 2307: 2302: 2287: 2284: 2283: 2282: 2275: 2261: 2260:is equal to id 2245: 2227: 2224: 2189: 2173: 2104: 2101: 2100: 2099: 2098: 2097: 2082: 2079: 2076: 2073: 2070: 2067: 2064: 2061: 2058: 2056: 2054: 2051: 2048: 2045: 2042: 2039: 2038: 2033: 2029: 2025: 2022: 2020: 2018: 2015: 2012: 2009: 2006: 2003: 1998: 1994: 1990: 1987: 1984: 1983: 1954: 1951: 1945: 1942: 1939: 1936: 1929: 1926: 1920: 1894: 1890: 1886: 1881: 1877: 1873: 1866: 1863: 1857: 1835: 1831: 1828: 1825: 1822: 1819: 1816: 1811: 1806: 1801: 1798: 1794: 1790: 1785: 1781: 1746: 1742: 1738: 1733: 1729: 1725: 1718: 1714: 1709: 1697: 1696: 1695: 1680: 1677: 1674: 1671: 1668: 1665: 1662: 1659: 1656: 1653: 1650: 1647: 1644: 1641: 1638: 1635: 1632: 1629: 1627: 1625: 1622: 1619: 1616: 1613: 1610: 1609: 1606: 1603: 1600: 1598: 1596: 1593: 1590: 1587: 1584: 1581: 1578: 1575: 1572: 1569: 1566: 1563: 1560: 1557: 1556: 1522: 1519: 1516: 1513: 1510: 1507: 1504: 1501: 1498: 1495: 1492: 1462: 1457: 1452: 1449: 1438: 1425: 1419: 1415: 1411: 1408: 1403: 1399: 1395: 1392: 1389: 1386: 1383: 1380: 1377: 1373: 1369: 1366: 1363: 1360: 1357: 1354: 1351: 1329: 1324: 1319: 1316: 1313: 1310: 1307: 1304: 1301: 1297: 1293: 1290: 1269: 1263: 1259: 1255: 1252: 1248: 1244: 1241: 1238: 1235: 1232: 1211: 1205: 1201: 1197: 1194: 1190: 1186: 1183: 1180: 1177: 1174: 1152: 1147: 1142: 1138: 1134: 1131: 1128: 1125: 1112: 1109: 1095: 1088: 1079: 1072: 1055: 1048: 1031: 1024: 980: 977: 958: 932:is the torus, 896: 893: 890: 885: 881: 860: 857: 854: 851: 848: 845: 842: 839: 836: 833: 828: 824: 803: 783: 780: 777: 774: 771: 768: 765: 745: 742: 739: 734: 730: 726: 723: 720: 717: 714: 711: 688: 685: 680: 676: 655: 652: 647: 643: 622: 619: 616: 613: 610: 607: 604: 584: 581: 578: 575: 570: 566: 545: 542: 539: 536: 533: 530: 527: 461: 458: 455: 435: 432: 429: 426: 423: 420: 417: 414: 411: 408: 405: 385: 382: 379: 376: 373: 370: 367: 364: 361: 358: 355: 319: 316: 313: 310: 307: 304: 301: 298: 295: 292: 289: 231: 228: 53:, a branch of 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 5980: 5969: 5966: 5964: 5961: 5959: 5956: 5955: 5953: 5938: 5930: 5926: 5923: 5921: 5918: 5916: 5913: 5912: 5911: 5903: 5901: 5897: 5893: 5891: 5887: 5883: 5881: 5876: 5871: 5869: 5861: 5860: 5857: 5851: 5848: 5846: 5843: 5841: 5838: 5836: 5833: 5831: 5828: 5826: 5823: 5822: 5820: 5818: 5814: 5808: 5807:Orientability 5805: 5803: 5800: 5798: 5795: 5793: 5790: 5788: 5785: 5784: 5782: 5778: 5772: 5769: 5767: 5764: 5762: 5759: 5757: 5754: 5752: 5749: 5747: 5744: 5742: 5739: 5735: 5732: 5730: 5727: 5726: 5725: 5722: 5718: 5715: 5713: 5710: 5708: 5705: 5703: 5700: 5698: 5695: 5694: 5693: 5690: 5688: 5685: 5683: 5680: 5678: 5674: 5671: 5670: 5668: 5664: 5659: 5649: 5646: 5644: 5643:Set-theoretic 5641: 5637: 5634: 5633: 5632: 5629: 5625: 5622: 5621: 5620: 5617: 5615: 5612: 5610: 5607: 5605: 5604:Combinatorial 5602: 5600: 5597: 5595: 5592: 5591: 5589: 5585: 5581: 5574: 5569: 5567: 5562: 5560: 5555: 5554: 5551: 5543: 5537: 5533: 5528: 5524: 5520: 5519: 5514: 5510: 5506: 5502: 5501: 5496: 5492: 5488: 5482: 5478: 5473: 5472: 5468: 5460: 5456: 5452: 5450:0-89871-544-X 5446: 5442: 5441: 5433: 5430: 5425: 5421: 5417: 5413: 5409: 5405: 5401: 5397: 5392: 5391:gr-qc/0609054 5387: 5383: 5379: 5372: 5369: 5363: 5362: 5357: 5354: 5347: 5344: 5339: 5335: 5331: 5329:9780521795401 5325: 5321: 5314: 5311: 5306: 5305: 5300: 5294: 5290: 5284: 5281: 5276: 5272: 5268: 5266:9780521795401 5262: 5258: 5251: 5248: 5243: 5239: 5233: 5230: 5219: 5215: 5209: 5206: 5194: 5193: 5188: 5182: 5179: 5167: 5161: 5158: 5152: 5148: 5145: 5143: 5140: 5138: 5135: 5133: 5130: 5128: 5125: 5122: 5119: 5118: 5114: 5112: 5110: 5106: 5102: 5098: 5079: 5076: 5073: 5065: 5061: 5052: 5048: 5029: 5026: 5023: 5017: 5010: 5006: 4984: 4981: 4978: 4972: 4969: 4966: 4955: 4951: 4947: 4943: 4939: 4935: 4930: 4928: 4924: 4920: 4916: 4912: 4908: 4900: 4898: 4896: 4891: 4886: 4881: 4876: 4871: 4866: 4861: 4856: 4852: 4848: 4844: 4840: 4836: 4832: 4828: 4824: 4820: 4815: 4810: 4805: 4800: 4795: 4790: 4785: 4780: 4776: 4772: 4768: 4764: 4760: 4756: 4752: 4748: 4743: 4741: 4737: 4733: 4729: 4728: 4723: 4717: 4709: 4707: 4705: 4689: 4686: 4683: 4675: 4670: 4651: 4643: 4640: 4637: 4606: 4602: 4576: 4572: 4568: 4565: 4557: 4553: 4527: 4519: 4516: 4513: 4497: 4493: 4489: 4471: 4463: 4460: 4457: 4451: 4448: 4440: 4436: 4432: 4416: 4410: 4407: 4404: 4401: 4398: 4388: 4380: 4378: 4376: 4372: 4367: 4365: 4359: 4354: 4349: 4342: 4337: 4332: 4326: 4319: 4315: 4307: 4297: 4292: 4285: 4278: 4273: 4265: 4258: 4253: 4248: 4242: 4238: 4234: 4227: 4219: 4214: 4212: 4210: 4206: 4202: 4198: 4194: 4190: 4186: 4182: 4178: 4170: 4168: 4166: 4161: 4156: 4149: 4142: 4135: 4131: 4124: 4120: 4113: 4109: 4105: 4100: 4096: 4089: 4082: 4078: 4074: 4069: 4067: 4063: 4059: 4055: 4051: 4047: 4043: 4039: 4035: 4031: 4026: 4024: 4021: −  4020: 4016: 4012: 4008: 4004: 4000: 3996: 3992: 3988: 3984: 3980: 3976: 3972: 3968: 3964: 3960: 3955: 3953: 3948: 3946: 3942: 3938: 3934: 3930: 3926: 3922: 3918: 3914: 3910: 3906: 3896: 3892: 3882: 3873: 3861: 3859: 3857: 3853: 3849: 3845: 3841: 3837: 3833: 3829: 3825: 3821: 3815: 3809: 3805: 3798: 3794: 3790: 3786: 3782: 3778: 3774: 3769: 3765: 3760: 3756: 3752: 3747: 3743: 3739: 3735: 3731: 3727: 3723: 3719: 3715: 3711: 3707: 3703: 3695: 3690: 3688: 3686: 3682: 3673: 3666: 3660: 3656: 3652: 3644: 3640: 3636: 3625: 3621: 3613: 3609: 3605: 3601: 3597: 3593: 3589: 3586: 3582: 3578: 3574: 3570: 3566: 3563: 3559: 3555: 3552: 3549: 3545: 3541: 3538: 3537: 3536: 3534: 3530: 3526: 3522: 3514: 3512: 3498: 3478: 3469: 3455: 3435: 3413: 3409: 3401: 3385: 3378:to any space 3363: 3359: 3351: 3335: 3327: 3326:null-homotopy 3311: 3303: 3287: 3276:Null-homotopy 3275: 3270: 3266: 3251: 3231: 3227: 3223: 3216: 3200: 3193: 3177: 3169: 3148: 3142: 3137: 3134: 3131: 3109: 3103: 3098: 3095: 3092: 3079: 3074: 3045: 3035: 3030: 3016:, by writing 3003: 3000: 2997: 2994: 2991: 2969: 2966: 2963: 2960: 2957: 2953: 2949: 2944: 2934: 2929: 2915: 2912: 2911:vector bundle 2908: 2891: 2888: 2859: 2856: 2853: 2849: 2839: 2833: 2828: 2818: 2815: 2793: 2789: 2768: 2762: 2759: 2756: 2749: 2745: 2726: 2723: 2720: 2716: 2712: 2706: 2700: 2695: 2680: 2679: 2662: 2656: 2651: 2636: 2618: 2614: 2605: 2586: 2575: 2571: 2565: 2562: 2559: 2553: 2548: 2544: 2540: 2537: 2534: 2528: 2525: 2522: 2516: 2494: 2465: 2461: 2436: 2425: 2402: 2387: 2377: 2374: 2371: 2368: 2345: 2339: 2334: 2305: 2290: 2289: 2285: 2280: 2276: 2273: 2269: 2268: 2267: 2264: 2258: 2254: 2248: 2242: 2238: 2233: 2232:homeomorphism 2225: 2223: 2221: 2217: 2213: 2209: 2208:homotopy type 2205: 2201: 2197: 2192: 2186: 2182: 2176: 2171: 2166: 2162: 2156: 2152: 2148: 2142: 2138: 2134: 2130: 2126: 2122: 2118: 2114: 2110: 2102: 2080: 2077: 2071: 2068: 2065: 2057: 2049: 2046: 2043: 2031: 2027: 2021: 2013: 2010: 2007: 2001: 1996: 1992: 1988: 1985: 1974: 1973: 1971: 1949: 1943: 1937: 1924: 1918: 1910: 1892: 1888: 1879: 1875: 1871: 1861: 1855: 1833: 1829: 1826: 1820: 1814: 1809: 1799: 1796: 1792: 1788: 1783: 1779: 1770: 1766: 1762: 1744: 1740: 1731: 1727: 1723: 1716: 1712: 1707: 1698: 1678: 1672: 1666: 1663: 1660: 1654: 1648: 1642: 1639: 1636: 1628: 1620: 1617: 1614: 1604: 1599: 1591: 1588: 1585: 1579: 1573: 1570: 1567: 1561: 1558: 1547: 1546: 1544: 1540: 1536: 1520: 1511: 1508: 1505: 1499: 1496: 1493: 1490: 1482: 1478: 1460: 1450: 1447: 1439: 1423: 1417: 1413: 1409: 1406: 1401: 1397: 1390: 1387: 1384: 1378: 1375: 1371: 1367: 1361: 1358: 1355: 1349: 1327: 1311: 1308: 1305: 1299: 1291: 1288: 1267: 1261: 1257: 1253: 1250: 1246: 1242: 1236: 1230: 1209: 1203: 1199: 1195: 1192: 1188: 1184: 1178: 1172: 1165:are given by 1150: 1132: 1129: 1126: 1123: 1115: 1114: 1110: 1108: 1105: 1101: 1094: 1087: 1078: 1071: 1065: 1061: 1054: 1047: 1041: 1037: 1030: 1023: 1018: 1014: 1010: 1006: 1002: 998: 994: 990: 986: 978: 976: 974: 970: 966: 961: 957: 953: 949: 945: 940: 935: 931: 926: 921: 917: 913: 908: 891: 883: 879: 855: 852: 849: 843: 840: 834: 826: 822: 801: 778: 775: 772: 766: 763: 740: 732: 728: 718: 715: 712: 702: 686: 683: 678: 674: 653: 650: 645: 641: 617: 614: 611: 605: 602: 582: 576: 573: 568: 564: 543: 537: 534: 531: 528: 525: 516: 514: 510: 506: 502: 498: 494: 490: 486: 483:as time then 482: 478: 473: 459: 456: 453: 430: 424: 421: 415: 412: 409: 403: 380: 374: 371: 365: 362: 359: 353: 345: 341: 340:unit interval 337: 334:of the space 333: 317: 308: 305: 302: 296: 293: 290: 287: 280: 276: 272: 268: 264: 261: 253: 249: 245: 241: 236: 229: 227: 225: 221: 217: 212: 210: 206: 202: 198: 194: 193: 183: 144: 143: 132: 96: 91: 80: 72: 71:Ancient Greek 68: 64: 60: 56: 52: 44: 39: 33: 19: 5937:Publications 5802:Chern number 5792:Betti number 5723: 5675: / 5666:Key concepts 5614:Differential 5534:. Springer. 5531: 5516: 5498: 5479:. Springer. 5476: 5439: 5432: 5381: 5377: 5371: 5359: 5346: 5319: 5313: 5302: 5289:Ghostarchive 5287:Archived at 5283: 5256: 5250: 5241: 5232: 5221:. Retrieved 5217: 5208: 5196:. Retrieved 5190: 5181: 5169:. Retrieved 5160: 5108: 5096: 5046: 5007:to the  5004: 4953: 4949: 4945: 4941: 4931: 4904: 4901:Applications 4894: 4889: 4884: 4879: 4874: 4869: 4864: 4859: 4850: 4846: 4842: 4838: 4830: 4826: 4822: 4818: 4813: 4808: 4803: 4798: 4793: 4788: 4783: 4774: 4770: 4762: 4758: 4754: 4750: 4746: 4744: 4735: 4731: 4725: 4719: 4671: 4491: 4490:with itself 4441:. If we fix 4438: 4434: 4390: 4375:cofibrations 4368: 4357: 4352: 4347: 4340: 4335: 4330: 4324: 4317: 4312:is called a 4305: 4295: 4290: 4283: 4276: 4271: 4263: 4256: 4251: 4246: 4244:and a cover 4240: 4236: 4232: 4229: 4187:between two 4174: 4164: 4162: 4154: 4147: 4140: 4133: 4122: 4118: 4111: 4107: 4103: 4087: 4080: 4070: 4065: 4057: 4053: 4052:) = (− 4049: 4045: 4041: 4037: 4027: 4022: 4018: 4014: 4010: 4006: 4002: 3998: 3994: 3990: 3986: 3982: 3978: 3974: 3970: 3966: 3962: 3958: 3956: 3949: 3944: 3940: 3936: 3932: 3928: 3924: 3916: 3912: 3908: 3904: 3902: 3895:trefoil knot 3855: 3851: 3847: 3843: 3835: 3831: 3827: 3819: 3813: 3807: 3803: 3796: 3792: 3788: 3784: 3780: 3776: 3772: 3767: 3763: 3758: 3754: 3750: 3745: 3741: 3737: 3733: 3725: 3721: 3717: 3713: 3709: 3705: 3699: 3678: 3671: 3664: 3658: 3654: 3650: 3642: 3638: 3634: 3623: 3619: 3607: 3603: 3595: 3591: 3580: 3576: 3561: 3553: 3547: 3539: 3532: 3528: 3524: 3518: 3470: 3325: 3301: 3279: 2781:with fibers 2748:fiber bundle 2279:Möbius strip 2262: 2256: 2252: 2246: 2240: 2236: 2229: 2220:contractible 2215: 2211: 2207: 2203: 2199: 2195: 2190: 2184: 2180: 2174: 2170:identity map 2164: 2160: 2158:, such that 2154: 2150: 2146: 2140: 2136: 2132: 2124: 2120: 2116: 2112: 2108: 2106: 1764: 1763:on the unit 1542: 1538: 1103: 1099: 1092: 1085: 1076: 1069: 1063: 1059: 1052: 1045: 1039: 1035: 1028: 1021: 1012: 1008: 1000: 996: 992: 988: 984: 982: 972: 968: 964: 959: 955: 951: 947: 943: 938: 933: 929: 924: 919: 915: 909: 517: 512: 508: 504: 500: 496: 492: 488: 487:describes a 484: 480: 474: 343: 335: 274: 270: 266: 262: 257: 247: 220:CW complexes 213: 203:, important 192:-moh-toh-pee 94: 66: 48: 5900:Wikiversity 5817:Key results 4769:induced by 4095:dimensional 4093:, in three- 4077:knot theory 4040:defined by 3965:) = − 3350:unit circle 3280:A function 1545:) given by 55:mathematics 5952:Categories 5746:CW complex 5687:Continuity 5677:Closed set 5636:cohomology 5495:"Homotopy" 5223:2019-08-17 5153:References 4956:, the set 4936:: one can 4877:) : π 4821:) for all 4801:) : H 4747:functorial 4364:fibrations 4345:such that 4281:such that 4215:Properties 3921:embeddings 3824:retraction 3770:such that 3757:× → 3585:isomorphic 3515:Invariance 3192:CW complex 1479:subset of 979:Properties 912:embeddings 699:, and the 633:such that 346:such that 240:embeddings 205:invariants 5925:geometric 5920:algebraic 5771:Cobordism 5707:Hausdorff 5702:connected 5619:Geometric 5609:Continuum 5599:Algebraic 5523:EMS Press 5505:EMS Press 5424:119707350 5416:0015-9018 5361:MathWorld 5356:"Isotopy" 5127:Homeotopy 4938:represent 4911:algebraic 4629:∂ 4554:π 4505:∂ 4414:→ 4408:: 4327:to a map 4099:embedding 4034:unit disc 3858:is used. 3818:Also, if 3648:)) where 3400:unit disk 3348:from the 3143:− 3135:− 3119:→ 3104:− 3096:− 3080:× 3036:− 2995:≤ 2967:− 2961:− 2950:≃ 2935:− 2857:− 2846:→ 2834:− 2816:π 2766:→ 2757:π 2724:− 2713:≃ 2701:− 2657:− 2572:⋅ 2563:− 2541:⋅ 2529:⋅ 2393:→ 2378:× 2340:≃ 2272:bijection 2069:− 2060:⟼ 2024:⟶ 2002:× 1953:→ 1928:→ 1885:→ 1865:→ 1827:≤ 1824:‖ 1818:‖ 1800:∈ 1737:→ 1640:− 1631:⟼ 1602:⟶ 1580:× 1518:→ 1451:⊆ 1388:− 1342:given by 1318:→ 1300:× 1141:→ 767:× 725:↦ 606:∈ 580:→ 541:→ 477:parameter 457:∈ 338:with the 330:from the 315:→ 297:× 67:homotopic 61:from one 5890:Wikibook 5868:Category 5756:Manifold 5724:Homotopy 5682:Interior 5673:Open set 5631:Homology 5580:Topology 5459:52377653 5338:45420394 5291:and the 5275:45420394 5198:22 April 5171:22 April 5115:See also 4594:, where 4496:boundary 4334: : 4274:→ 4270: : 4255:→ 4249: : 4235: : 4201:3-sphere 4181:timelike 4062:rotation 4048:,  4013:,  3943:,  3801:for all 3779:,  3762:between 3753: : 3691:Variants 3670:∈ 3653: : 3622:,  3569:homology 2984:for any 2635:1-sphere 2417:between 2286:Examples 2149: : 2135: : 2119:between 1111:Examples 1098: : 1058: : 1034: : 967:, where 446:for all 95:homotopy 51:topology 5915:general 5717:uniform 5697:compact 5648:Digital 5525:, 2001 5507:, 2001 5469:Sources 5396:Bibcode 5304:YouTube 5192:YouTube 4740:functor 4488:crossed 4203:can be 3925:isotopy 3862:Isotopy 3850:. When 1907:be the 1759:be the 995:taking 332:product 252:isotopy 242:of the 224:spectra 142:-tə-pee 5910:Topics 5712:metric 5587:Fields 5538:  5483:  5457:  5447:  5422:  5414:  5336:  5326:  5273:  5263:  5053:group 4724:. The 4381:Groups 4104:deform 3891:unknot 3730:subset 2909:Every 2637:) and 1970:origin 1847:. Let 1477:convex 69:(from 57:, two 5692:Space 5420:S2CID 5386:arXiv 4887:) → π 4867:) = π 4811:) → H 4791:) = H 4757:from 4175:On a 3826:from 3822:is a 3728:is a 3190:of a 2633:(the 1535:paths 1475:is a 495:into 246:into 244:torus 222:, or 90:tópos 85:τόπος 79:homós 43:paths 5536:ISBN 5481:ISBN 5455:OCLC 5445:ISBN 5412:ISSN 5334:OCLC 5324:ISBN 5271:OCLC 5261:ISBN 5200:2022 5173:2022 5049:-th 4913:and 4909:for 4849:and 4841:and 4829:and 4773:and 4753:and 4734:and 4437:and 4314:lift 4139:and 4086:and 3981:) = 3919:are 3907:and 3889:The 3834:and 3811:and 3791:) = 3783:) = 3766:and 3740:and 3724:and 3712:and 3606:and 3594:and 3583:are 3579:and 3571:and 3531:and 3001:< 2889:> 2746:Any 2453:and 2277:The 2214:and 2198:and 2178:and 2144:and 2129:maps 2123:and 2115:, a 2111:and 1769:disk 1699:Let 1541:(or 1533:are 1483:and 1223:and 1083:and 987:and 918:and 666:and 595:for 396:and 265:and 199:and 75:ὁμός 5404:doi 5111:. 4897:). 4761:to 4316:of 4153:to 4071:In 4036:in 3971:not 3969:is 3846:to 3842:of 3830:to 3816:∈ . 3732:of 3720:to 3602:of 3590:If 3575:of 3564:is. 3556:is 3550:is. 3542:is 3428:to 1116:If 1011:to 999:to 936:is 928:. 794:to 701:map 511:to 491:of 479:of 472:. 342:to 207:in 190:HOH 138:hə- 49:In 5954:: 5521:, 5515:, 5503:, 5497:, 5453:. 5418:. 5410:. 5402:. 5394:. 5382:38 5380:. 5358:. 5332:. 5301:. 5295:: 5269:. 5240:. 5216:. 5189:. 4929:. 4706:. 4669:. 4377:. 4366:. 4356:= 4350:○ 4293:○ 4289:= 4211:. 4167:. 4025:. 4019:yx 3954:. 3935:, 3806:∈ 3674:.) 3657:→ 3637:, 3267:A 2678:. 2576:id 2426:id 2230:A 2222:. 2172:id 2153:→ 2139:→ 1944::= 1789::= 1708:id 1185::= 1102:→ 1062:→ 1051:, 1038:→ 1027:, 942:, 914:, 226:. 218:, 211:. 186:, 179:iː 173:oʊ 164:oʊ 158:oʊ 145:; 140:MO 135:, 128:iː 73:: 5572:e 5565:t 5558:v 5544:. 5489:. 5461:. 5426:. 5406:: 5398:: 5388:: 5364:. 5340:. 5307:. 5277:. 5244:. 5226:. 5202:. 5175:. 5109:G 5097:X 5083:) 5080:G 5077:, 5074:X 5071:( 5066:n 5062:H 5047:n 5033:) 5030:n 5027:, 5024:G 5021:( 5018:K 5005:X 4991:] 4988:) 4985:n 4982:, 4979:G 4976:( 4973:K 4970:, 4967:X 4964:[ 4954:X 4950:G 4946:X 4942:X 4895:Y 4893:( 4890:n 4885:X 4883:( 4880:n 4875:g 4873:( 4870:n 4865:f 4863:( 4860:n 4851:g 4847:f 4843:g 4839:f 4831:Y 4827:X 4823:n 4819:Y 4817:( 4814:n 4809:X 4807:( 4804:n 4799:g 4797:( 4794:n 4789:f 4787:( 4784:n 4775:g 4771:f 4763:Y 4759:X 4755:g 4751:f 4736:Y 4732:X 4690:1 4687:= 4684:n 4657:) 4652:n 4648:] 4644:1 4641:, 4638:0 4635:[ 4632:( 4607:0 4603:y 4582:) 4577:0 4573:y 4569:, 4566:Y 4563:( 4558:n 4533:) 4528:n 4524:] 4520:1 4517:, 4514:0 4511:[ 4508:( 4492:n 4472:n 4468:] 4464:1 4461:, 4458:0 4455:[ 4452:= 4449:X 4439:Y 4435:X 4417:Y 4411:X 4405:g 4402:, 4399:f 4360:. 4358:H 4353:H 4348:p 4341:Y 4336:X 4331:H 4325:H 4321:0 4318:h 4310:0 4306:h 4303:( 4300:0 4296:h 4291:p 4287:0 4284:H 4277:Y 4272:X 4268:0 4264:h 4257:Y 4252:Y 4247:p 4241:Y 4237:X 4233:H 4158:2 4155:K 4151:1 4148:K 4144:2 4141:K 4137:1 4134:K 4126:2 4123:K 4119:t 4115:1 4112:K 4108:t 4091:2 4088:K 4084:1 4081:K 4066:f 4058:y 4054:x 4050:y 4046:x 4044:( 4042:f 4038:R 4023:x 4015:y 4011:x 4009:( 4007:H 4003:H 3999:f 3995:g 3991:f 3987:f 3983:x 3979:x 3977:( 3975:g 3967:x 3963:x 3961:( 3959:f 3945:t 3941:x 3939:( 3937:H 3933:t 3929:H 3917:Y 3913:X 3909:g 3905:f 3852:K 3848:K 3844:X 3836:f 3832:K 3828:X 3820:g 3814:t 3808:K 3804:k 3799:) 3797:k 3795:( 3793:g 3789:k 3787:( 3785:f 3781:t 3777:k 3775:( 3773:H 3768:g 3764:f 3759:Y 3755:X 3751:H 3746:K 3742:g 3738:f 3734:X 3726:K 3722:Y 3718:X 3714:g 3710:f 3672:X 3668:0 3665:x 3659:Y 3655:X 3651:f 3646:0 3643:x 3641:( 3639:f 3635:Y 3633:( 3631:1 3627:0 3624:x 3620:X 3618:( 3616:1 3608:Y 3604:X 3596:Y 3592:X 3587:. 3581:Y 3577:X 3562:Y 3554:X 3548:Y 3540:X 3533:Y 3529:X 3499:X 3479:X 3456:f 3436:X 3414:2 3410:D 3386:X 3364:1 3360:S 3336:f 3312:f 3288:f 3264:. 3252:X 3232:A 3228:/ 3224:X 3201:X 3178:A 3155:) 3152:} 3149:0 3146:{ 3138:k 3132:n 3127:R 3122:( 3116:) 3113:} 3110:0 3107:{ 3099:k 3093:n 3088:R 3083:( 3075:k 3070:R 3046:k 3041:R 3031:n 3026:R 3004:n 2998:k 2992:0 2970:1 2964:k 2958:n 2954:S 2945:k 2940:R 2930:n 2925:R 2906:. 2892:0 2884:R 2860:1 2854:n 2850:S 2843:} 2840:0 2837:{ 2829:n 2824:R 2819:: 2794:b 2790:F 2769:B 2763:E 2760:: 2741:. 2727:1 2721:n 2717:S 2710:} 2707:0 2704:{ 2696:n 2691:R 2666:} 2663:0 2660:{ 2652:2 2647:R 2619:1 2615:S 2603:. 2587:n 2582:R 2569:) 2566:t 2560:1 2557:( 2554:+ 2549:0 2545:p 2538:t 2535:= 2532:) 2526:, 2523:t 2520:( 2517:H 2495:n 2490:R 2466:0 2462:p 2437:n 2432:R 2403:n 2398:R 2388:n 2383:R 2375:I 2372:: 2369:H 2349:} 2346:0 2343:{ 2335:n 2330:R 2306:n 2301:R 2263:Y 2257:g 2253:f 2247:X 2241:f 2237:g 2216:Y 2212:X 2200:Y 2196:X 2191:Y 2185:g 2181:f 2175:X 2165:f 2161:g 2155:X 2151:Y 2147:g 2141:Y 2137:X 2133:f 2125:Y 2121:X 2113:Y 2109:X 2081:. 2078:x 2075:) 2072:t 2066:1 2063:( 2053:) 2050:t 2047:, 2044:x 2041:( 2032:n 2028:B 2017:] 2014:1 2011:, 2008:0 2005:[ 1997:n 1993:B 1989:: 1986:H 1950:0 1941:) 1938:x 1935:( 1925:0 1919:c 1893:n 1889:B 1880:n 1876:B 1872:: 1862:0 1856:c 1834:} 1830:1 1821:x 1815:: 1810:n 1805:R 1797:x 1793:{ 1784:n 1780:B 1767:- 1765:n 1745:n 1741:B 1732:n 1728:B 1724:: 1717:n 1713:B 1679:. 1676:) 1673:s 1670:( 1667:g 1664:t 1661:+ 1658:) 1655:s 1652:( 1649:f 1646:) 1643:t 1637:1 1634:( 1624:) 1621:t 1618:, 1615:s 1612:( 1605:C 1595:] 1592:1 1589:, 1586:0 1583:[ 1577:] 1574:1 1571:, 1568:0 1565:[ 1562:: 1559:H 1521:C 1515:] 1512:1 1509:, 1506:0 1503:[ 1500:: 1497:g 1494:, 1491:f 1461:n 1456:R 1448:C 1424:) 1418:x 1414:e 1410:t 1407:+ 1402:3 1398:x 1394:) 1391:t 1385:1 1382:( 1379:, 1376:x 1372:( 1368:= 1365:) 1362:t 1359:, 1356:x 1353:( 1350:H 1328:2 1323:R 1315:] 1312:1 1309:, 1306:0 1303:[ 1296:R 1292:: 1289:H 1268:) 1262:x 1258:e 1254:, 1251:x 1247:( 1243:= 1240:) 1237:x 1234:( 1231:g 1210:) 1204:3 1200:x 1196:, 1193:x 1189:( 1182:) 1179:x 1176:( 1173:f 1151:2 1146:R 1137:R 1133:: 1130:g 1127:, 1124:f 1104:Z 1100:X 1096:1 1093:g 1089:2 1086:g 1080:1 1077:f 1073:2 1070:f 1064:Z 1060:Y 1056:2 1053:g 1049:2 1046:f 1040:Y 1036:X 1032:1 1029:g 1025:1 1022:f 1013:Y 1009:X 1001:g 997:f 993:H 989:g 985:f 973:t 969:t 965:t 960:t 956:h 952:g 948:R 944:f 939:R 934:Y 930:X 925:R 920:g 916:f 895:) 892:x 889:( 884:t 880:h 859:) 856:t 853:, 850:x 847:( 844:H 841:= 838:) 835:x 832:( 827:t 823:h 802:Y 782:] 779:1 776:, 773:0 770:[ 764:X 744:) 741:x 738:( 733:t 729:h 722:) 719:t 716:, 713:x 710:( 687:g 684:= 679:1 675:h 654:f 651:= 646:0 642:h 621:] 618:1 615:, 612:0 609:[ 603:t 583:Y 577:X 574:: 569:t 565:h 544:Y 538:X 535:: 532:g 529:, 526:f 513:g 509:f 505:g 501:f 497:g 493:f 485:H 481:H 460:X 454:x 434:) 431:x 428:( 425:g 422:= 419:) 416:1 413:, 410:x 407:( 404:H 384:) 381:x 378:( 375:f 372:= 369:) 366:0 363:, 360:x 357:( 354:H 344:Y 336:X 318:Y 312:] 309:1 306:, 303:0 300:[ 294:X 291:: 288:H 275:Y 271:X 267:g 263:f 254:. 248:R 182:/ 176:p 170:t 167:ˌ 161:m 155:h 152:ˈ 149:/ 131:/ 125:p 122:ə 119:t 116:ɒ 113:m 110:ˈ 107:ə 104:h 101:/ 97:( 34:. 20:)

Index

Relative homotopy
Homotopic groups

paths
topology
mathematics
continuous functions
topological space
Ancient Greek
/həˈmɒtəp/
hə-MO-tə-pee
/ˈhmˌtp/
HOH-moh-toh-pee
homotopy groups
cohomotopy groups
invariants
algebraic topology
compactly generated spaces
CW complexes
spectra

embeddings
torus
isotopy
continuous functions
continuous function
product
unit interval
parameter
map

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