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Dold–Thom theorem

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is that it is of particular interest for algebraic geometry since it allows one to reformulate homology only using homotopy. Since applying methods from algebraic topology can be quite insightful in this field, one tries to transfer these to algebraic geometry. This could be achieved for homotopy
566: 2117: 1146: 777:{\displaystyle \qquad \dots \xrightarrow {\partial } {\tilde {h}}_{n}(A)\xrightarrow {i_{*}} {\tilde {h}}_{n}(X)\xrightarrow {q_{*}} {\tilde {h}}_{n}(X/A)\xrightarrow {\partial } {\tilde {h}}_{n-1}(A)\xrightarrow {i_{*}} \dots } 2020: 70:, one can see that the latter actually defines a homology theory. Nevertheless, none of these allow one to directly reduce homology to homotopy. This advantage of the Dold-Thom theorem makes it particularly interesting for 962: 2031: 904: 1930: 1033: 1176: 1038: 1603:
One should bear in mind that there is a variety of different proofs although this one is seemingly the most popular. For example, proofs have been established via
1659:. All sides except possibly the one at the bottom commute in this diagram. Therefore, one sees that the whole diagram commutes when considering where 1 ∈ π 1945: 1673:
gets mapped to. However, by using the suspension isomorphisms for homotopy respectively homology groups, the task reduces to showing the assertion for
909: 2112:{\displaystyle \operatorname {SP} \left(\bigvee _{\alpha }X_{\alpha }\right)\cong \prod _{\alpha }\operatorname {SP} (X_{\alpha }),} 1776:
and that it therefore has the weak homotopy type of a generalised Eilenberg-MacLane space. The theorem amounts to saying that all
2584: 2565: 2487: 2456: 2352: 863: 1321:) consisting of connected complexes. First of all, as every CW complex is homotopy equivalent to a simplicial complex, 1271:. So it only remains to verify the axioms 2 and 4. The crux of this undertaking will be the first point. This is where 1263:
is a functor fulfilling property 1 as SP is a homotopy functor. Moreover, the third property is clear since one has SP(
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In order to verify the compatibility with the Hurewicz homomorphism, it suffices to show that the statement holds for
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with the infinite symmetric product defines a reduced homology theory. One of the main tools used in doing so are
1877: 1611:. One can also proof the theorem using other notions of a homology theory (the Eilenberg-Steenrod axioms e.g.). 997: 67: 1742:
Another application is a new proof of a theorem first stated by Moore. It basically predicates the following:
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groups. The most common version of its proof consists of showing that the composition of the homotopy group
2253: 32: 1702:. One gets the result by first forming the homotopy pushout square of the inclusions of the intersection 52: 2448: 58:
There are several other theorems constituting relations between homotopy and homology, for example the
2547: 1757: 1594: 414: 1349:. This will not change anything as SP is a homotopy functor. It suffices to prove by induction that 1141:{\displaystyle \qquad i_{*}\colon \varinjlim {\tilde {h}}_{n}(X_{\lambda })\to {\tilde {h}}_{n}(X),} 2327: 1151: 1462:
restricted to each of the preimages of these three sets is a quasifibration. It can be shown that
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and shows that these two sets are, together with their intersection, distinguished, i.e. that
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What distinguishes the Dold-Thom theorem from other alternative foundations of homology like
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is not even a fibration. However, that turns out not to be the case: Take an arbitrary path
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Dold, Albrecht; Thom, René (1958), "Quasifaserungen und unendliche symmetrische Produkte",
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given by summing up the images of the coordinates. But as there are natural homeomorphisms
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Verifying the fourth axiom can be done quite elementary, in contrast to the previous one.
8: 2261:. So the Dold-Thom theorem yields a foundation of homology having an algebraic analogue. 2258: 1935:
if one takes the maps to be basepoint-preserving. Then the special H-space structure of
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theory, but for homology theory only in a rather limited way using a formulation via
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Spanier, Edwin (1959), "Infinite Symmetric Products, Function Spaces and Duality",
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On the homotopy groups of the infinite symmetric product of a connected CW complex
2427: 2249: 1482:) and the long exact sequence of such a one implies that axiom 2 is satisfied as 402: 28: 2171:) is the Hurewicz homomorphism and as H-spaces have abelian fundamental groups, 2362:
Bandklayder, Lauren (2019), "The Dold-Thom Theorem via Factoriation Homology",
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from the category of basepointed, connected CW complexes to the category of
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One direct consequence of the Dold-Thom theorem is a new way to derive the
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denotes reduced homology and SP stands for the infinite symmetric product.
2236:)) into the cartesian product is a weak homotopy equivalence. Therefore, 1630: 2534: 2479: 2423: 1420:= 0 this is trivially fulfilled. In the induction step, one decomposes 182: 51:. The theorem has been generalised in various ways, for example by the 36: 2240:
has the weak homotopy type of a generalised Eilenberg-MacLane space.
2213:). This also implies that the natural inclusion of the weak product Π 245:. The common point of the two copies is supposed to be the point 0 ∈ 238: 2526: 2407: 758: 714: 661: 616: 578: 2556: 957:{\displaystyle i_{\lambda }^{\mu }\colon X_{\lambda }\to X_{\mu }} 126:
It is also very useful that there exists an isomorphism φ : π
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May, J. Peter (1990), "Weak Equivalences and Quasifibrations",
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themselves. Then one applies SP to that square and finally π
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chose in their initial proof a slight modification of the
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The following example illustrates that the requirement of
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Aguilar, Marcelo; Gitler, Samuel; Prieto, Carlos (2008).
845:) be the system of compact subspaces of a pointed space 2034: 1948: 1880: 1154: 1041: 1000: 912: 866: 569: 899:{\displaystyle i_{\lambda }\colon X_{\lambda }\to X} 2342: 1772:) has this property for every connected CW complex 2111: 2014: 1924: 1170: 1140: 1027: 956: 898: 776: 516:There are natural boundary homomorphisms ∂ : 219:being a CW complex cannot be dropped offhand: Let 1471:is then already distinguished itself. Therefore, 1184:One can show that for a reduced homology theory ( 2576: 994:) is a direct system as well with the morphisms 2345:Algebraic Topology from a Homotopical Viewpoint 320:) defined by φ(, ) = () is a homeomorphism for 2557:The Dold-Thom theorem for infinity categories? 1749:A path-connected, commutative and associative 386:One wants to show that the family of functors 179:), meaning that one has a commutative diagram 1593:, hence different from the basepoint, so the 563:being connected, yielding an exact sequence 1615:Compatibility with the Hurewicz homomorphism 2566:Group structure on Eilenberg-MacLane spaces 2361: 2179:. Thanks to the Dold-Thom theorem, each SP( 1925:{\displaystyle \bigvee _{n}M(G_{n},n)\to X} 1478:is indeed a quasifibration on the whole SP( 1693: 2495: 2375: 2347:. Springer Science & Business Media. 1028:{\displaystyle {i_{\lambda }^{\mu }}_{*}} 2391: 1627:. This is because one then gets a prism 860:together with the inclusions. Denote by 2514: 2437: 2364:Journal of Homotopy and Related Sources 1756:with a strict identity element has the 417:, namely calling a family of functors ( 249:meeting every circle. On the one hand, 2577: 381: 2243: 2196:)) is now an Eilenberg-MacLane space 1737: 1677:. But in this case the inclusion SP( 1548:). Then any lift of this path to SP( 196:is the map induced by the inclusion 2465: 1581:. But this means that its endpoint 1313:is a quasifibration for a CW pair ( 241:of two copies of the cone over the 13: 2276:Dold and Thom (1958), Example 6.11 2122:with Π denoting the weak product, 1734:to the resulting pullback square. 1629: 1278:The goal is to prove that the map 715: 579: 274:) is trivial. On the other hand, π 181: 14: 2596: 2541: 1178:is required to be an isomorphism. 2470:, Lecture Notes in Mathematics, 849:containing the basepoint. Then ( 1688: 1206:there is a natural isomorphism 1042: 570: 149:) which is compatible with the 62:. Another approach is given by 2585:Theorems in algebraic topology 2330:An essay by Thomas Barnet-Lamb 2321: 2312: 2297: 2288: 2285:Dold and Thom (1958), Satz 6.8 2279: 2270: 2175:also induces isomorphisms on π 2103: 2090: 2006: 1998: 1979: 1916: 1913: 1894: 1532:and interpret it as a path in 1429:into an open neighbourhood of 1297:) induced by the quotient map 1132: 1126: 1114: 1104: 1101: 1088: 1076: 941: 890: 751: 745: 727: 707: 693: 681: 654: 648: 636: 609: 603: 591: 334:But this implies that either π 77: 68:Freudenthal suspension theorem 1: 2336: 1685:) is a homotopy equivalence. 1171:{\displaystyle i_{\lambda *}} 260:) is an infinite group while 2496:Piccinini, Renzo A. (1992). 2294:Hatcher (2002), Theorem 2C.5 2254:Alexander-Spanier cohomology 1828:inducing an isomorphism on π 7: 2498:Lectures on Homotopy Theory 2163:) induced by the inclusion 509:), where ≃ denotes pointed 304:)) holds since φ : SP( 86:For a connected CW complex 53:Almgren isomorphism theorem 10: 2601: 2548:Why the Dold-Thom theorem? 2449:Cambridge University Press 2318:Hatcher (2002), Lemma 4.31 1838:≥ 2 and an isomorphism on 2377:10.1007/s40062-018-0219-1 2126:induces isomorphisms on π 1807:). Then there exist maps 1595:Homotopy lifting property 1374:is a quasifibration with 1035:. Then the homomorphism 415:Eilenberg-Steenrod axioms 2264: 1783: 1337:will be replaced by the 1762:Eilenberg-MacLane space 1700:Mayer-Vietoris sequence 1694:Mayer-Vietoris sequence 1647:) represented by a map 1597:fails to be fulfilled. 1496:One may wonder whether 445:reduced homology theory 2468:Springer Lecture Notes 2113: 2016: 1926: 1634: 1605:factorisation homology 1172: 1142: 1029: 958: 900: 778: 186: 64:stable homotopy theory 2518:Annals of Mathematics 2395:Annals of Mathematics 2328:The Dold-Thom theorem 2304:The Dold-Thom theorem 2114: 2017: 1927: 1637:for each Element ∈ π 1633: 1329:can be assumed to be 1173: 1143: 1030: 959: 901: 796:is the inclusion and 779: 185: 151:Hurewicz homomorphism 2032: 1946: 1878: 1871:). These give a map 1331:simplicial complexes 1152: 1039: 998: 910: 864: 812:is the quotient map. 567: 511:homotopy equivalence 39:are the same as its 1017: 927: 835:denotes the circle. 769: 718: 672: 627: 582: 382:Sketch of the proof 2480:10.1007/BFb0083834 2444:Algebraic Topology 2244:Algebraic geometry 2109: 2083: 2055: 2012: 1975: 1922: 1890: 1758:weak homotopy type 1738:A theorem of Moore 1635: 1168: 1138: 1064: 1025: 1003: 954: 913: 896: 774: 187: 84:Dold-Thom theorem. 72:algebraic geometry 21:algebraic topology 2489:978-3-540-52658-2 2458:978-0-521-79540-1 2398:, Second Series, 2354:978-0-387-22489-3 2074: 2046: 1966: 1881: 1760:of a generalised 1710:of two subspaces 1589:is a multiple of 1552:) is of the form 1524:approaching some 1341:of the inclusion 1117: 1079: 1057: 964:the inclusion if 770: 730: 719: 684: 673: 639: 628: 594: 583: 547:) for each pair ( 378:) does not hold. 33:symmetric product 25:Dold-Thom theorem 2592: 2537: 2511: 2492: 2462: 2434: 2388: 2379: 2358: 2331: 2325: 2319: 2316: 2310: 2301: 2295: 2292: 2286: 2283: 2277: 2274: 2118: 2116: 2115: 2110: 2102: 2101: 2082: 2070: 2066: 2065: 2064: 2054: 2021: 2019: 2018: 2013: 2005: 2001: 1991: 1990: 1974: 1931: 1929: 1928: 1923: 1906: 1905: 1889: 1339:mapping cylinder 1275:come into play: 1177: 1175: 1174: 1169: 1167: 1166: 1147: 1145: 1144: 1139: 1125: 1124: 1119: 1118: 1110: 1100: 1099: 1087: 1086: 1081: 1080: 1072: 1065: 1052: 1051: 1034: 1032: 1031: 1026: 1024: 1023: 1018: 1016: 1011: 963: 961: 960: 955: 953: 952: 940: 939: 926: 921: 905: 903: 902: 897: 889: 888: 876: 875: 783: 781: 780: 775: 768: 767: 754: 744: 743: 732: 731: 723: 710: 703: 692: 691: 686: 685: 677: 671: 670: 657: 647: 646: 641: 640: 632: 626: 625: 612: 602: 601: 596: 595: 587: 574: 447:if they satisfy 243:Hawaiian earring 66:. Thanks to the 60:Hurewicz theorem 41:reduced homology 31:of the infinite 27:states that the 2600: 2599: 2595: 2594: 2593: 2591: 2590: 2589: 2575: 2574: 2544: 2527:10.2307/1970099 2508: 2490: 2459: 2408:10.2307/1970005 2355: 2339: 2334: 2326: 2322: 2317: 2313: 2302: 2298: 2293: 2289: 2284: 2280: 2275: 2271: 2267: 2246: 2231: 2218: 2208: 2191: 2178: 2158: 2147: 2139: 2131: 2097: 2093: 2078: 2060: 2056: 2050: 2045: 2041: 2033: 2030: 2029: 1986: 1982: 1970: 1965: 1961: 1947: 1944: 1943: 1901: 1897: 1885: 1879: 1876: 1875: 1866: 1846: 1833: 1819: 1802: 1796: 1786: 1740: 1733: 1696: 1691: 1664: 1642: 1617: 1609:simplicial sets 1588: 1572: 1566: 1560: 1511: 1502: 1488: 1477: 1470: 1457: 1447: 1438: 1428: 1415: 1406: 1399: 1382: 1373: 1364: 1355: 1333:. Furthermore, 1284: 1273:quasifibrations 1262: 1246: 1227: 1214: 1205: 1204: 1192: 1159: 1155: 1153: 1150: 1149: 1148:induced by the 1120: 1109: 1108: 1107: 1095: 1091: 1082: 1071: 1070: 1069: 1056: 1047: 1043: 1040: 1037: 1036: 1019: 1012: 1007: 1002: 1001: 999: 996: 995: 993: 986: 977: 970: 948: 944: 935: 931: 922: 917: 911: 908: 907: 884: 880: 871: 867: 865: 862: 861: 855: 844: 822: 763: 759: 733: 722: 721: 720: 699: 687: 676: 675: 674: 666: 662: 642: 631: 630: 629: 621: 617: 597: 586: 585: 584: 568: 565: 564: 542: 524: 504: 491: 482: 475: 438: 437: 425: 403:homology theory 401:∘ SP defines a 400: 394: 384: 373: 362: 351: 337: 296: 285: 277: 266: 255: 195: 174: 161: 144: 131: 121: 108: 95: 80: 49:quasifibrations 35:of a connected 29:homotopy groups 17: 12: 11: 5: 2598: 2588: 2587: 2573: 2572: 2563: 2554: 2543: 2542:External links 2540: 2539: 2538: 2512: 2506: 2493: 2488: 2463: 2457: 2439:Hatcher, Allen 2435: 2402:(2): 239–281, 2389: 2370:(2): 579–593, 2359: 2353: 2338: 2335: 2333: 2332: 2320: 2311: 2296: 2287: 2278: 2268: 2266: 2263: 2245: 2242: 2227: 2214: 2204: 2187: 2176: 2156: 2145: 2137: 2127: 2120: 2119: 2108: 2105: 2100: 2096: 2092: 2089: 2086: 2081: 2077: 2073: 2069: 2063: 2059: 2053: 2049: 2044: 2040: 2037: 2023: 2022: 2011: 2008: 2004: 2000: 1997: 1994: 1989: 1985: 1981: 1978: 1973: 1969: 1964: 1960: 1957: 1954: 1951: 1933: 1932: 1921: 1918: 1915: 1912: 1909: 1904: 1900: 1896: 1893: 1888: 1884: 1862: 1842: 1829: 1815: 1798: 1792: 1785: 1782: 1766: 1765: 1739: 1736: 1731: 1695: 1692: 1690: 1687: 1660: 1638: 1616: 1613: 1586: 1568: 1562: 1556: 1507: 1500: 1486: 1475: 1466: 1452: 1443: 1433: 1424: 1411: 1404: 1395: 1378: 1369: 1360: 1353: 1282: 1258: 1244: 1223: 1210: 1202: 1194: 1188: 1182: 1181: 1180: 1179: 1165: 1162: 1158: 1137: 1134: 1131: 1128: 1123: 1116: 1113: 1106: 1103: 1098: 1094: 1090: 1085: 1078: 1075: 1068: 1063: 1060: 1055: 1050: 1046: 1022: 1015: 1010: 1006: 991: 982: 975: 968: 951: 947: 943: 938: 934: 930: 925: 920: 916: 895: 892: 887: 883: 879: 874: 870: 853: 842: 836: 818: 813: 773: 766: 762: 757: 753: 750: 747: 742: 739: 736: 729: 726: 717: 713: 709: 706: 702: 698: 695: 690: 683: 680: 669: 665: 660: 656: 653: 650: 645: 638: 635: 624: 620: 615: 611: 608: 605: 600: 593: 590: 581: 577: 573: 537: 520: 514: 500: 487: 480: 473: 441:abelian groups 435: 427: 421: 396: 390: 383: 380: 371: 360: 349: 335: 294: 283: 275: 264: 253: 193: 170: 157: 140: 127: 124: 123: 117: 104: 91: 79: 76: 15: 9: 6: 4: 3: 2: 2597: 2586: 2583: 2582: 2580: 2571: 2570:StackExchange 2567: 2564: 2562: 2558: 2555: 2553: 2549: 2546: 2545: 2536: 2532: 2528: 2524: 2520: 2519: 2513: 2509: 2507:9780080872827 2503: 2499: 2494: 2491: 2485: 2481: 2477: 2473: 2469: 2464: 2460: 2454: 2450: 2446: 2445: 2440: 2436: 2433: 2429: 2425: 2421: 2417: 2413: 2409: 2405: 2401: 2397: 2396: 2390: 2387: 2383: 2378: 2373: 2369: 2365: 2360: 2356: 2350: 2346: 2341: 2340: 2329: 2324: 2315: 2309: 2305: 2300: 2291: 2282: 2273: 2269: 2262: 2260: 2255: 2251: 2241: 2239: 2235: 2230: 2226: 2222: 2217: 2212: 2207: 2203: 2199: 2195: 2190: 2186: 2182: 2174: 2170: 2166: 2162: 2155: 2151: 2143: 2136:≥ 2. But as π 2135: 2130: 2125: 2106: 2098: 2094: 2087: 2084: 2079: 2075: 2071: 2067: 2061: 2057: 2051: 2047: 2042: 2038: 2035: 2028: 2027: 2026: 2009: 2002: 1995: 1992: 1987: 1983: 1976: 1971: 1967: 1962: 1958: 1955: 1952: 1949: 1942: 1941: 1940: 1939:yields a map 1938: 1919: 1910: 1907: 1902: 1898: 1891: 1886: 1882: 1874: 1873: 1872: 1870: 1865: 1861: 1857: 1854: 1850: 1845: 1841: 1837: 1832: 1827: 1823: 1818: 1814: 1810: 1806: 1801: 1795: 1791: 1781: 1779: 1775: 1771: 1768:Note that SP( 1763: 1759: 1755: 1752: 1748: 1745: 1744: 1743: 1735: 1729: 1725: 1721: 1717: 1713: 1709: 1705: 1701: 1686: 1684: 1680: 1676: 1672: 1668: 1663: 1658: 1654: 1650: 1646: 1641: 1632: 1628: 1626: 1622: 1612: 1610: 1606: 1601: 1598: 1596: 1592: 1584: 1580: 1576: 1571: 1565: 1559: 1555: 1551: 1547: 1543: 1539: 1535: 1531: 1527: 1523: 1519: 1515: 1510: 1506: 1499: 1494: 1492: 1485: 1481: 1474: 1469: 1465: 1461: 1455: 1451: 1446: 1442: 1436: 1432: 1427: 1423: 1419: 1414: 1410: 1403: 1398: 1394: 1390: 1386: 1381: 1377: 1372: 1368: 1363: 1359: 1352: 1348: 1344: 1340: 1336: 1332: 1328: 1324: 1320: 1316: 1312: 1308: 1304: 1300: 1296: 1292: 1288: 1281: 1276: 1274: 1270: 1266: 1261: 1257: 1252: 1250: 1243: 1239: 1235: 1231: 1226: 1222: 1218: 1213: 1209: 1201: 1197: 1191: 1187: 1163: 1160: 1156: 1135: 1129: 1121: 1111: 1096: 1092: 1083: 1073: 1066: 1061: 1058: 1053: 1048: 1044: 1020: 1013: 1008: 1004: 990: 985: 981: 974: 967: 949: 945: 936: 932: 928: 923: 918: 914: 906:respectively 893: 885: 881: 877: 872: 868: 859: 858:direct system 852: 848: 841: 837: 834: 830: 826: 821: 817: 814: 811: 807: 803: 799: 795: 791: 787: 771: 764: 760: 755: 748: 740: 737: 734: 724: 711: 704: 700: 696: 688: 678: 667: 663: 658: 651: 643: 633: 622: 618: 613: 606: 598: 588: 575: 571: 562: 558: 554: 550: 546: 540: 536: 532: 528: 523: 519: 515: 512: 508: 503: 499: 495: 490: 486: 479: 472: 468: 464: 460: 456: 452: 451: 450: 449: 448: 446: 442: 434: 430: 424: 420: 416: 412: 408: 404: 399: 393: 389: 379: 377: 370: 366: 358: 355: 348: 344: 341: 332: 330: 326: 323: 319: 315: 311: 307: 303: 300: 292: 289: 281: 273: 270: 263: 259: 252: 248: 244: 240: 236: 233: 229: 226: 222: 218: 213: 211: 207: 203: 199: 192: 184: 180: 178: 173: 169: 165: 160: 155: 152: 148: 143: 139: 135: 130: 120: 116: 112: 107: 103: 99: 94: 89: 85: 82: 81: 75: 73: 69: 65: 61: 56: 54: 50: 46: 42: 38: 34: 30: 26: 22: 2561:MathOverflow 2552:MathOverflow 2516: 2500:. Elsevier. 2497: 2471: 2467: 2443: 2399: 2393: 2367: 2363: 2344: 2323: 2314: 2299: 2290: 2281: 2272: 2247: 2237: 2233: 2228: 2224: 2220: 2215: 2210: 2205: 2201: 2197: 2193: 2188: 2184: 2180: 2172: 2168: 2164: 2160: 2153: 2149: 2141: 2133: 2128: 2123: 2121: 2024: 1936: 1934: 1868: 1863: 1859: 1855: 1848: 1843: 1839: 1835: 1830: 1825: 1821: 1816: 1812: 1808: 1804: 1799: 1793: 1789: 1787: 1777: 1773: 1769: 1767: 1753: 1746: 1741: 1727: 1723: 1719: 1715: 1711: 1707: 1703: 1697: 1689:Applications 1682: 1678: 1674: 1670: 1666: 1661: 1656: 1652: 1648: 1644: 1639: 1636: 1624: 1620: 1618: 1602: 1599: 1590: 1582: 1578: 1574: 1569: 1563: 1557: 1553: 1549: 1545: 1541: 1537: 1533: 1529: 1525: 1521: 1517: 1516:∈ [0, 1) in 1513: 1508: 1504: 1497: 1495: 1490: 1483: 1479: 1472: 1467: 1463: 1459: 1453: 1449: 1444: 1440: 1434: 1430: 1425: 1421: 1417: 1412: 1408: 1401: 1396: 1392: 1388: 1384: 1379: 1375: 1370: 1366: 1361: 1357: 1350: 1346: 1342: 1334: 1326: 1322: 1318: 1314: 1310: 1306: 1302: 1298: 1294: 1290: 1286: 1279: 1277: 1268: 1264: 1259: 1255: 1253: 1248: 1241: 1237: 1233: 1229: 1224: 1220: 1216: 1211: 1207: 1199: 1195: 1189: 1185: 1183: 988: 983: 979: 972: 965: 850: 846: 839: 832: 828: 824: 819: 815: 809: 805: 801: 797: 793: 789: 785: 560: 556: 552: 548: 544: 538: 534: 530: 526: 521: 517: 506: 501: 497: 493: 488: 484: 477: 470: 466: 462: 458: 454: 444: 432: 428: 422: 418: 397: 391: 387: 385: 375: 368: 364: 356: 353: 346: 342: 339: 333: 328: 324: 317: 313: 309: 305: 301: 298: 290: 287: 279: 271: 268: 261: 257: 250: 246: 234: 231: 227: 224: 220: 216: 214: 209: 205: 201: 197: 190: 188: 176: 171: 167: 163: 158: 153: 146: 141: 137: 133: 128: 125: 118: 114: 110: 105: 101: 97: 92: 87: 83: 57: 24: 18: 2521:: 142–198, 1853:Moore space 831:≠ 1, where 78:The theorem 2474:: 91–101, 2337:References 1851:= 1 for a 1577:for every 827:) = 0 for 37:CW complex 2416:0003-486X 2386:256333418 2099:α 2088:⁡ 2080:α 2076:∏ 2072:≅ 2062:α 2052:α 2048:⋁ 2039:⁡ 2007:→ 1968:⋁ 1959:⁡ 1953:: 1917:→ 1883:⋁ 1493:) holds. 1254:Clearly, 1164:∗ 1161:λ 1115:~ 1105:→ 1097:λ 1077:~ 1067:⁡ 1062:→ 1054:: 1049:∗ 1021:∗ 1014:μ 1009:λ 950:μ 942:→ 937:λ 929:: 924:μ 919:λ 891:→ 886:λ 878:: 873:λ 772:… 765:∗ 738:− 728:~ 716:∂ 682:~ 668:∗ 637:~ 623:∗ 592:~ 580:∂ 572:⋯ 239:wedge sum 113:), where 90:one has π 2579:Category 2441:(2002). 1747:Theorem. 1489:() ≅ SP( 1356: : 756:→ 712:→ 659:→ 614:→ 576:→ 45:functors 2535:1970099 2432:0097062 2424:1970005 2259:sheaves 1751:H-space 1681:) → SP( 1416:). For 1289:) → SP( 1236:) with 856:) is a 555:) with 469:, then 322:compact 312:) → SP( 308:) × SP( 237:be the 208:) → SP( 2533:  2504:  2486:  2455:  2430:  2422:  2414:  2384:  2351:  1567:with α 1391:) and 784:where 359:) or π 293:)) × π 282:)) ≅ π 189:where 23:, the 2531:JSTOR 2420:JSTOR 2382:S2CID 2265:Notes 2167:→ SP( 2144:) → π 1784:Proof 1722:into 1540:⊂ SP( 1383:= SP( 1285:: SP( 838:Let ( 367:)) ≅ 345:)) ≅ 204:= SP( 2502:ISBN 2484:ISBN 2472:1425 2453:ISBN 2412:ISSN 2349:ISBN 2308:nLab 2250:Cech 2152:) = 2132:for 1824:) → 1788:Let 1726:and 1669:) ≅ 1512:for 1439:and 1325:and 1267:) ≃ 1219:) ≅ 559:and 533:) → 496:) → 411:Thom 409:and 407:Dold 363:(SP( 338:(SP( 327:and 297:(SP( 286:(SP( 278:(SP( 166:) → 136:) → 100:) ≅ 2568:on 2559:on 2550:on 2523:doi 2476:doi 2404:doi 2372:doi 2306:on 2252:or 2219:SP( 2148:SP( 1847:if 1834:if 1797:= π 1607:or 1251:). 1059:lim 453:If 395:= π 212:). 156:: π 132:SP( 96:SP( 19:In 2581:: 2529:, 2482:, 2451:. 2447:. 2428:MR 2426:, 2418:, 2410:, 2400:67 2380:, 2368:14 2366:, 2232:, 2209:, 2192:, 2085:SP 2036:SP 1956:SP 1867:, 1820:, 1718:⊂ 1714:, 1706:∩ 1655:→ 1651:: 1623:= 1573:∈ 1528:∈ 1520:− 1456:−1 1448:− 1437:−1 1400:= 1365:→ 1345:→ 1317:, 1305:→ 1301:: 1242:h̃ 1240:= 1232:; 1221:H̃ 1208:h̃ 1186:h̃ 980:h̃ 978:. 971:⊂ 816:h̃ 804:→ 800:: 792:→ 788:: 551:, 541:−1 535:h̃ 518:h̃ 498:h̃ 485:h̃ 483:: 476:= 465:→ 461:: 457:≃ 443:a 419:h̃ 405:. 331:. 316:∨ 230:∨ 223:= 200:: 168:H̃ 138:H̃ 115:H̃ 102:H̃ 74:. 55:. 2525:: 2510:. 2478:: 2461:. 2406:: 2374:: 2357:. 2238:X 2234:n 2229:n 2225:G 2223:( 2221:M 2216:n 2211:n 2206:n 2202:G 2200:( 2198:K 2194:n 2189:n 2185:G 2183:( 2181:M 2177:1 2173:f 2169:X 2165:X 2161:X 2159:( 2157:1 2154:H 2150:X 2146:1 2142:X 2140:( 2138:1 2134:n 2129:n 2124:f 2107:, 2104:) 2095:X 2091:( 2068:) 2058:X 2043:( 2010:X 2003:) 1999:) 1996:n 1993:, 1988:n 1984:G 1980:( 1977:M 1972:n 1963:( 1950:f 1937:X 1920:X 1914:) 1911:n 1908:, 1903:n 1899:G 1895:( 1892:M 1887:n 1869:n 1864:n 1860:G 1858:( 1856:M 1849:n 1844:1 1840:H 1836:n 1831:n 1826:X 1822:n 1817:n 1813:G 1811:( 1809:M 1805:X 1803:( 1800:n 1794:n 1790:G 1778:k 1774:Y 1770:Y 1764:. 1754:X 1732:* 1728:B 1724:A 1720:X 1716:B 1712:A 1708:B 1704:A 1683:S 1679:S 1675:S 1671:Z 1667:S 1665:( 1662:n 1657:X 1653:S 1649:f 1645:X 1643:( 1640:n 1625:S 1621:X 1591:a 1587:1 1585:α 1583:a 1579:t 1575:A 1570:t 1564:t 1561:α 1558:t 1554:x 1550:X 1546:A 1544:/ 1542:X 1538:A 1536:/ 1534:X 1530:A 1526:a 1522:A 1518:X 1514:t 1509:t 1505:x 1501:* 1498:p 1491:A 1487:* 1484:p 1480:X 1476:* 1473:p 1468:n 1464:B 1460:p 1454:n 1450:B 1445:n 1441:B 1435:n 1431:B 1426:n 1422:B 1418:n 1413:n 1409:B 1407:( 1405:* 1402:p 1397:n 1393:E 1389:A 1387:/ 1385:X 1380:n 1376:B 1371:n 1367:B 1362:n 1358:E 1354:* 1351:p 1347:X 1343:A 1335:X 1327:A 1323:X 1319:A 1315:X 1311:A 1309:/ 1307:X 1303:X 1299:p 1295:A 1293:/ 1291:X 1287:X 1283:* 1280:p 1269:S 1265:S 1260:n 1256:h 1249:S 1247:( 1245:1 1238:G 1234:G 1230:X 1228:( 1225:n 1217:X 1215:( 1212:n 1203:0 1200:N 1198:∈ 1196:n 1193:) 1190:n 1157:i 1136:, 1133:) 1130:X 1127:( 1122:n 1112:h 1102:) 1093:X 1089:( 1084:n 1074:h 1045:i 1005:i 992:λ 989:X 987:( 984:n 976:μ 973:X 969:λ 966:X 946:X 933:X 915:i 894:X 882:X 869:i 854:λ 851:X 847:X 843:λ 840:X 833:S 829:n 825:S 823:( 820:n 810:A 808:/ 806:X 802:X 798:q 794:X 790:A 786:i 761:i 752:) 749:A 746:( 741:1 735:n 725:h 708:) 705:A 701:/ 697:X 694:( 689:n 679:h 664:q 655:) 652:X 649:( 644:n 634:h 619:i 610:) 607:A 604:( 599:n 589:h 561:A 557:X 553:A 549:X 545:A 543:( 539:n 531:A 529:/ 527:X 525:( 522:n 513:. 507:Y 505:( 502:n 494:X 492:( 489:n 481:* 478:g 474:* 471:f 467:Y 463:X 459:g 455:f 436:0 433:N 431:∈ 429:n 426:) 423:n 398:n 392:n 388:h 376:X 374:( 372:1 369:H 365:X 361:1 357:H 354:C 352:( 350:1 347:H 343:H 340:C 336:1 329:Y 325:X 318:Y 314:X 310:Y 306:X 302:H 299:C 295:1 291:H 288:C 284:1 280:X 276:1 272:H 269:C 267:( 265:1 262:H 258:X 256:( 254:1 251:H 247:H 235:H 232:C 228:H 225:C 221:X 217:X 210:X 206:X 202:X 198:i 194:* 191:i 177:X 175:( 172:n 164:X 162:( 159:n 154:h 147:X 145:( 142:n 134:X 129:n 119:n 111:X 109:( 106:n 98:X 93:n 88:X

Index

algebraic topology
homotopy groups
symmetric product
CW complex
reduced homology
functors
quasifibrations
Almgren isomorphism theorem
Hurewicz theorem
stable homotopy theory
Freudenthal suspension theorem
algebraic geometry
Hurewicz homomorphism

wedge sum
Hawaiian earring
compact
homology theory
Dold
Thom
Eilenberg-Steenrod axioms
abelian groups
homotopy equivalence
direct system
quasifibrations
simplicial complexes
mapping cylinder
Homotopy lifting property
factorisation homology
simplicial sets

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