Knowledge (XXG)

Homotopy principle

Source đź“ť

17: 873: 865:
A non-holonomic solution to this relation would consist in the data of two functions, a differentiable function f(x), and a continuous function g(x), with g(x) nowhere vanishing. A holonomic solution gives rise to a non-holonomic solution by taking g(x) = f'(x). The space of non-holonomic solutions
780:
into a holonomic one in the class of non-holonomic solutions. Thus in the presence of h-principle, a differential topological problem reduces to an algebraic topological problem. More explicitly this means that apart from the topological obstruction there is no other obstruction to the existence of a
1141:
to holonomic ones but also can be arbitrarily well approximated by the holonomic ones (by going back and forth, like parallel parking in a limited space) – note that this approximates both the position and the angle of the car arbitrarily closely. This implies that, theoretically, it is possible to
788:
Many underdetermined partial differential equations satisfy the h-principle. However, the falsity of an h-principle is also an interesting statement, intuitively this means the objects being studied have non-trivial geometry that cannot be reduced to topology. As an example, embedded
958:
in complex numbers). Note that here there are no immersions of order 0, as those would need to turn back on themselves. Extending this to circles immersed in the plane – the immersion condition is precisely the condition that the derivative does not vanish – the
768:
In order to check whether a solution to our original equation exists, one can first check if there is a non-holonomic solution. Usually this is quite easy, and if there is no non-holonomic solution, then our original equation did not have any solutions.
621: 857:
A holonomic solution to this relation is a function whose derivative is nowhere vanishing, i.e. a strictly monotone differentiable function, either increasing or decreasing. The space of such functions consists of two disjoint
752: 518: 1335:-embedding (respectively, immersion). This is also a dense h-principle, and can be proven by an essentially similar "wrinkling" – or rather, circling – technique to the car in the plane, though it is much more involved. 986:
which requires the partial derivatives in each direction to not vanish and to be linearly independent, and the resulting analog of the Gauss map is a map to the Stiefel manifold, or more generally between frame bundles.
1121: 253: 1536: 158: 390: 923: 1306: 848: 1689: 956: 1137:
A non-holonomic solution in this case, roughly speaking, corresponds to a motion of the car by sliding in the plane. In this case the non-holonomic solutions are not only
1244: 328: 288: 1477: 1441: 1053: 1876: 1840: 1774: 1747: 1716: 1660: 1633: 1599: 1572: 1408: 1333: 1271: 1198: 1167: 1497: 1033: 1013: 529: 1887:
David Spring, Convex integration theory - solutions to the h-principle in geometry and topology, Monographs in Mathematics 92, Birkhauser-Verlag, 1998
632: 398: 995:
As another simple example, consider a car moving in the plane. The position of a car in the plane is determined by three parameters: two coordinates
2017: 982:
are much further-reaching generalizations, and much more involved, but similar in principle – immersion requires the derivative to have rank
888:
This trivial example has nontrivial generalizations: extending this to immersions of a circle into itself classifies them by order (or
1957: 1935: 1061: 2022: 166: 1945: 60: 960: 877: 68: 1142:
parallel park in any space longer than the length of your car. It also implies that, in a contact 3 manifold, any curve is
41: 1718:
because a small oscillating sphere would provide a large lower bound for the principal curvatures, and therefore for the
45: 16: 1502: 978:, and Hirsch's generalization of this to immersions of manifolds being classified as homotopy classes of maps of 896:
and applying the above analysis to the resulting monotone map – the linear map corresponds to multiplying angle:
98: 893: 793:
in a symplectic manifold do not satisfy an h-principle, to prove this one needs to find invariants coming from
333: 1212: 899: 794: 52:
PDEs or PDRs, such as the immersion problem, isometric immersion problem, fluid dynamics, and other areas.
1208: 1131: 790: 49: 1276: 63:
and Anthony V. Phillips. It was based on earlier results that reduced partial differential relations to
1665: 1035:
for the location (a good choice is the location of the midpoint between the back wheels) and an angle
1806:
S. Smale, The classification of immersions of spheres in Euclidean spaces. Ann. of Math(2) 69 (1959)
928: 1605: 785:
is much easier to handle and can be addressed with the obstruction theory for topological bundles.
813: 1984: 1222: 1541:
Any open manifold admits a (non-complete) Riemannian metric of positive (or negative) curvature.
1359:
Here we list a few counter-intuitive results which can be proved by applying the h-principle:
301: 261: 1953: 1931: 1777: 1446: 872: 1413: 1038: 1994: 975: 56: 1854: 1818: 1752: 1725: 1694: 1638: 1611: 1577: 1550: 1386: 1311: 1249: 1176: 1145: 1719: 1544: 1170: 21: 1055:
which describes the orientation of the car. The motion of the car satisfies the equation
869:
Thus the inclusion of holonomic into non-holonomic solutions satisfies the h-principle.
866:
again consists of two disjoint convex sets, according as g(x) is positive or negative.
616:{\displaystyle y_{j}={\partial ^{k}f \over \partial u_{j_{1}}\ldots \partial u_{j_{k}}}.} 971:
and showing that this satisfies an h-principle; here again order 0 is more complicated.
862:: the increasing ones and the decreasing ones, and has the homotopy type of two points. 810:
Perhaps the simplest partial differential relation is for the derivative to not vanish:
1482: 1018: 998: 964: 889: 881: 880:
shows that immersions of the circle in the plane satisfy an h-principle, expressed by
761:, and a solution of the system which is also solution of our original PDE is called a 2011: 1173:
curve. This last property is stronger than the general h-principle; it is called the
1999: 1968: 979: 1921: 1913: 67:, particularly for immersions. The first evidence of h-principle appeared in the 747:{\displaystyle \Psi _{}^{}(u_{1},u_{2},\dots ,u_{m},y_{1},y_{2},\dots ,y_{N})=0} 513:{\displaystyle \Psi _{}^{}(u_{1},u_{2},\dots ,u_{m},y_{1},y_{2},\dots ,y_{N})=0} 29: 859: 1216: 1138: 968: 1749:
this has to be equal to 1 everywhere, the Gauss curvature of the standard
974:
Smale's classification of immersions of spheres as the homotopy groups of
1878:
Isometric Imbeddings I, II. Nederl. Acad. Wetensch. Proc. Ser A 58 (1955)
1127: 777: 64: 1797:
M. W. Hirsch, Immersions of manifold. Trans. Amer. Math. Soc. 93 (1959)
1126:
since a non-skidding car must move in the direction of its wheels. In
1344:
Removal of Singularities technique developed by Gromov and Eliashberg
20:
The homotopy principle generalizes such results as Smale's proof of
1989: 1722:
of the immersed sphere, but on the other hand if the immersion is
871: 15: 1383:|. Then there is a continuous one-parameter family of functions 1308:
or larger can be arbitrarily well approximated by an isometric
854:
differential relation, as this is a function in one variable.
1116:{\displaystyle {\dot {x}}\sin \alpha ={\dot {y}}\cos \alpha .} 1898:
Mathematical Omnibus: Thirty Lectures on Classic Mathematics
248:{\displaystyle \Psi (u_{1},u_{2},\dots ,u_{m},J_{f}^{k})=0} 91:
which satisfies a partial differential equation of degree
75:
embedding theorem and the Smale–Hirsch immersion theorem.
781:
holonomic solution. The topological problem of finding a
392:
Then our original equation can be thought as a system of
1350:
Convex integration based on the work of Nash and Kuiper.
1347:
Sheaf technique based on the work of Smale and Hirsch.
1857: 1821: 1755: 1728: 1697: 1668: 1641: 1614: 1580: 1553: 1505: 1485: 1449: 1416: 1389: 1314: 1279: 1252: 1225: 1179: 1148: 1064: 1041: 1021: 1001: 931: 902: 816: 635: 532: 401: 336: 304: 264: 169: 101: 1967:
De Lellis, Camillo; Székelyhidi, László Jr. (2012).
523:and some number of equations of the following type 1870: 1834: 1768: 1741: 1710: 1683: 1654: 1627: 1593: 1566: 1530: 1491: 1471: 1435: 1402: 1327: 1300: 1265: 1238: 1192: 1161: 1115: 1047: 1027: 1007: 950: 917: 842: 746: 615: 512: 384: 322: 282: 247: 152: 1920:Eliashberg, Y.; Mishachev, N.; Ariki, S. (2002). 71:. This was followed by the Nash–Kuiper isometric 1973:-principle and the equations of fluid dynamics" 1842:Isometric Imbedding. Ann. of Math(2) 60 (1954) 1547:without creasing or tearing can be done using 1207:While this example is simple, compare to the 8: 1531:{\displaystyle \operatorname {grad} (f_{t})} 1130:terms, not all paths in the task space are 153:{\displaystyle (u_{1},u_{2},\dots ,u_{m})} 1998: 1988: 1862: 1856: 1826: 1820: 1760: 1754: 1733: 1727: 1702: 1696: 1675: 1671: 1670: 1667: 1646: 1640: 1619: 1613: 1606:Nash-Kuiper C isometric embedding theorem 1585: 1579: 1558: 1552: 1519: 1504: 1484: 1454: 1448: 1421: 1415: 1394: 1388: 1319: 1313: 1286: 1281: 1278: 1257: 1251: 1230: 1224: 1184: 1178: 1153: 1147: 1090: 1089: 1066: 1065: 1063: 1040: 1020: 1000: 967:by considering the homotopy class of the 942: 930: 901: 815: 729: 710: 697: 684: 665: 652: 642: 640: 634: 599: 594: 576: 571: 553: 546: 537: 531: 495: 476: 463: 450: 431: 418: 408: 406: 400: 385:{\displaystyle y_{1},y_{2},\dots ,y_{N}.} 373: 354: 341: 335: 314: 309: 303: 274: 269: 263: 230: 225: 212: 193: 180: 168: 141: 122: 109: 100: 1608:, in particular implies that there is a 1790: 918:{\displaystyle \theta \mapsto n\theta } 290:stands for all partial derivatives of 776:if any non-holonomic solution can be 48:(PDRs). The h-principle is good for 7: 298:. Let us exchange every variable in 1662:into an arbitrarily small ball of 1363:Cone eversion. Consider functions 1301:{\displaystyle \mathbf {R} ^{m+1}} 1231: 637: 587: 564: 550: 403: 170: 83:Assume we want to find a function 14: 1930:. American Mathematical Society. 1635:isometric immersion of the round 40:) is a very general way to solve 1684:{\displaystyle \mathbb {R} ^{3}} 1282: 2000:10.1090/S0273-0979-2012-01376-9 2018:Partial differential equations 1950:Partial differential relations 1525: 1512: 951:{\displaystyle z\mapsto z^{n}} 935: 906: 831: 825: 735: 645: 501: 411: 330:for new independent variables 236: 173: 147: 102: 46:partial differential relations 42:partial differential equations 1: 1339:Ways to prove the h-principle 892:), by lifting the map to the 1246:) embedding or immersion of 843:{\displaystyle f'(x)\neq 0.} 1691:. This immersion cannot be 1239:{\displaystyle C^{\infty }} 44:(PDEs), and more generally 2039: 1896:D. Fuchs, S. Tabachnikov, 55:The theory was started by 1916:, translation Kiki Hudson 1914:Embeddings and immersions 1538:is not zero at any point. 961:Whitney–Graustein theorem 878:Whitney–Graustein theorem 795:pseudo-holomorphic curves 774:satisfies the h-principle 323:{\displaystyle J_{f}^{k}} 283:{\displaystyle J_{f}^{k}} 69:Whitney–Graustein theorem 1472:{\displaystyle f_{1}=-f} 894:universal covering space 160:. One can rewrite it as 2023:Mathematical principles 1436:{\displaystyle f_{0}=f} 1048:{\displaystyle \alpha } 1872: 1836: 1770: 1743: 1712: 1685: 1656: 1629: 1595: 1568: 1532: 1493: 1473: 1437: 1404: 1329: 1302: 1267: 1240: 1215:, which says that any 1209:Nash embedding theorem 1194: 1163: 1117: 1049: 1029: 1009: 952: 919: 885: 844: 783:non-holonomic solution 759:non-holonomic solution 748: 617: 514: 386: 324: 284: 249: 154: 25: 1977:Bull. Amer. Math. Soc 1873: 1871:{\displaystyle C^{1}} 1837: 1835:{\displaystyle C^{1}} 1771: 1769:{\displaystyle S^{2}} 1744: 1742:{\displaystyle C^{2}} 1713: 1711:{\displaystyle C^{2}} 1686: 1657: 1655:{\displaystyle S^{2}} 1630: 1628:{\displaystyle C^{1}} 1596: 1594:{\displaystyle S^{2}} 1569: 1567:{\displaystyle C^{1}} 1533: 1494: 1474: 1438: 1405: 1403:{\displaystyle f_{t}} 1330: 1328:{\displaystyle C^{1}} 1303: 1268: 1266:{\displaystyle M^{m}} 1241: 1195: 1193:{\displaystyle C^{0}} 1164: 1162:{\displaystyle C^{0}} 1118: 1050: 1030: 1010: 953: 920: 875: 850:Properly, this is an 845: 749: 618: 515: 387: 325: 285: 250: 155: 19: 1923:Introduction to the 1855: 1819: 1753: 1726: 1695: 1666: 1639: 1612: 1578: 1551: 1503: 1483: 1447: 1414: 1387: 1312: 1277: 1250: 1223: 1177: 1146: 1062: 1039: 1019: 999: 963:classified these by 929: 900: 814: 633: 530: 399: 334: 302: 262: 167: 99: 1213:Nash–Kuiper theorem 1211:, specifically the 644: 410: 319: 279: 235: 1868: 1832: 1766: 1739: 1708: 1681: 1652: 1625: 1591: 1564: 1528: 1489: 1469: 1433: 1400: 1325: 1298: 1263: 1236: 1190: 1159: 1113: 1045: 1025: 1005: 991:A car in the plane 948: 915: 886: 840: 806:Monotone functions 763:holonomic solution 744: 636: 613: 510: 402: 382: 320: 305: 280: 265: 245: 221: 150: 95:, in co-ordinates 34:homotopy principle 26: 1912:Masahisa Adachi, 1778:Theorema Egregium 1492:{\displaystyle t} 1202:dense h-principle 1098: 1074: 1028:{\displaystyle y} 1008:{\displaystyle x} 976:Stiefel manifolds 608: 294:up to order  2030: 2004: 2002: 1992: 1963: 1941: 1900: 1894: 1888: 1885: 1879: 1877: 1875: 1874: 1869: 1867: 1866: 1849: 1843: 1841: 1839: 1838: 1833: 1831: 1830: 1813: 1807: 1804: 1798: 1795: 1775: 1773: 1772: 1767: 1765: 1764: 1748: 1746: 1745: 1740: 1738: 1737: 1717: 1715: 1714: 1709: 1707: 1706: 1690: 1688: 1687: 1682: 1680: 1679: 1674: 1661: 1659: 1658: 1653: 1651: 1650: 1634: 1632: 1631: 1626: 1624: 1623: 1600: 1598: 1597: 1592: 1590: 1589: 1573: 1571: 1570: 1565: 1563: 1562: 1537: 1535: 1534: 1529: 1524: 1523: 1498: 1496: 1495: 1490: 1478: 1476: 1475: 1470: 1459: 1458: 1442: 1440: 1439: 1434: 1426: 1425: 1409: 1407: 1406: 1401: 1399: 1398: 1334: 1332: 1331: 1326: 1324: 1323: 1307: 1305: 1304: 1299: 1297: 1296: 1285: 1272: 1270: 1269: 1264: 1262: 1261: 1245: 1243: 1242: 1237: 1235: 1234: 1199: 1197: 1196: 1191: 1189: 1188: 1168: 1166: 1165: 1160: 1158: 1157: 1122: 1120: 1119: 1114: 1100: 1099: 1091: 1076: 1075: 1067: 1054: 1052: 1051: 1046: 1034: 1032: 1031: 1026: 1014: 1012: 1011: 1006: 957: 955: 954: 949: 947: 946: 924: 922: 921: 916: 849: 847: 846: 841: 824: 753: 751: 750: 745: 734: 733: 715: 714: 702: 701: 689: 688: 670: 669: 657: 656: 643: 641: 622: 620: 619: 614: 609: 607: 606: 605: 604: 603: 583: 582: 581: 580: 562: 558: 557: 547: 542: 541: 519: 517: 516: 511: 500: 499: 481: 480: 468: 467: 455: 454: 436: 435: 423: 422: 409: 407: 391: 389: 388: 383: 378: 377: 359: 358: 346: 345: 329: 327: 326: 321: 318: 313: 289: 287: 286: 281: 278: 273: 254: 252: 251: 246: 234: 229: 217: 216: 198: 197: 185: 184: 159: 157: 156: 151: 146: 145: 127: 126: 114: 113: 57:Yakov Eliashberg 2038: 2037: 2033: 2032: 2031: 2029: 2028: 2027: 2008: 2007: 1966: 1960: 1944: 1938: 1919: 1909: 1907:Further reading 1904: 1903: 1895: 1891: 1886: 1882: 1858: 1853: 1852: 1850: 1846: 1822: 1817: 1816: 1814: 1810: 1805: 1801: 1796: 1792: 1787: 1756: 1751: 1750: 1729: 1724: 1723: 1720:Gauss curvature 1698: 1693: 1692: 1669: 1664: 1663: 1642: 1637: 1636: 1615: 1610: 1609: 1581: 1576: 1575: 1554: 1549: 1548: 1545:Sphere eversion 1515: 1501: 1500: 1481: 1480: 1450: 1445: 1444: 1417: 1412: 1411: 1390: 1385: 1384: 1379:) = | 1371:without origin 1357: 1341: 1315: 1310: 1309: 1280: 1275: 1274: 1253: 1248: 1247: 1226: 1221: 1220: 1180: 1175: 1174: 1149: 1144: 1143: 1060: 1059: 1037: 1036: 1017: 1016: 997: 996: 993: 938: 927: 926: 898: 897: 817: 812: 811: 808: 803: 801:Simple examples 725: 706: 693: 680: 661: 648: 631: 630: 595: 590: 572: 567: 563: 549: 548: 533: 528: 527: 491: 472: 459: 446: 427: 414: 397: 396: 369: 350: 337: 332: 331: 300: 299: 260: 259: 208: 189: 176: 165: 164: 137: 118: 105: 97: 96: 81: 50:underdetermined 22:sphere eversion 12: 11: 5: 2036: 2034: 2026: 2025: 2020: 2010: 2009: 2006: 2005: 1964: 1958: 1942: 1936: 1917: 1908: 1905: 1902: 1901: 1889: 1880: 1865: 1861: 1851:N. Kuiper, On 1844: 1829: 1825: 1808: 1799: 1789: 1788: 1786: 1783: 1782: 1781: 1763: 1759: 1736: 1732: 1705: 1701: 1678: 1673: 1649: 1645: 1622: 1618: 1602: 1588: 1584: 1574:immersions of 1561: 1557: 1542: 1539: 1527: 1522: 1518: 1514: 1511: 1508: 1488: 1468: 1465: 1462: 1457: 1453: 1432: 1429: 1424: 1420: 1397: 1393: 1356: 1355:Some paradoxes 1353: 1352: 1351: 1348: 1345: 1340: 1337: 1322: 1318: 1295: 1292: 1289: 1284: 1260: 1256: 1233: 1229: 1187: 1183: 1156: 1152: 1124: 1123: 1112: 1109: 1106: 1103: 1097: 1094: 1088: 1085: 1082: 1079: 1073: 1070: 1044: 1024: 1004: 992: 989: 965:turning number 945: 941: 937: 934: 914: 911: 908: 905: 890:winding number 882:turning number 839: 836: 833: 830: 827: 823: 820: 807: 804: 802: 799: 755: 754: 743: 740: 737: 732: 728: 724: 721: 718: 713: 709: 705: 700: 696: 692: 687: 683: 679: 676: 673: 668: 664: 660: 655: 651: 647: 639: 626:A solution of 624: 623: 612: 602: 598: 593: 589: 586: 579: 575: 570: 566: 561: 556: 552: 545: 540: 536: 521: 520: 509: 506: 503: 498: 494: 490: 487: 484: 479: 475: 471: 466: 462: 458: 453: 449: 445: 442: 439: 434: 430: 426: 421: 417: 413: 405: 381: 376: 372: 368: 365: 362: 357: 353: 349: 344: 340: 317: 312: 308: 277: 272: 268: 256: 255: 244: 241: 238: 233: 228: 224: 220: 215: 211: 207: 204: 201: 196: 192: 188: 183: 179: 175: 172: 149: 144: 140: 136: 133: 130: 125: 121: 117: 112: 108: 104: 80: 77: 61:Mikhail Gromov 13: 10: 9: 6: 4: 3: 2: 2035: 2024: 2021: 2019: 2016: 2015: 2013: 2001: 1996: 1991: 1986: 1982: 1978: 1974: 1972: 1965: 1961: 1959:3-540-12177-3 1955: 1951: 1947: 1943: 1939: 1937:9780821832271 1933: 1929: 1928: 1924: 1918: 1915: 1911: 1910: 1906: 1899: 1893: 1890: 1884: 1881: 1863: 1859: 1848: 1845: 1827: 1823: 1812: 1809: 1803: 1800: 1794: 1791: 1784: 1779: 1761: 1757: 1734: 1730: 1721: 1703: 1699: 1676: 1647: 1643: 1620: 1616: 1607: 1603: 1586: 1582: 1559: 1555: 1546: 1543: 1540: 1520: 1516: 1509: 1506: 1486: 1466: 1463: 1460: 1455: 1451: 1430: 1427: 1422: 1418: 1395: 1391: 1382: 1378: 1374: 1370: 1366: 1362: 1361: 1360: 1354: 1349: 1346: 1343: 1342: 1338: 1336: 1320: 1316: 1293: 1290: 1287: 1258: 1254: 1227: 1218: 1214: 1210: 1205: 1203: 1185: 1181: 1172: 1154: 1150: 1140: 1135: 1133: 1129: 1110: 1107: 1104: 1101: 1095: 1092: 1086: 1083: 1080: 1077: 1071: 1068: 1058: 1057: 1056: 1042: 1022: 1002: 990: 988: 985: 981: 980:frame bundles 977: 972: 970: 966: 962: 943: 939: 932: 912: 909: 903: 895: 891: 883: 879: 874: 870: 867: 863: 861: 855: 853: 837: 834: 828: 821: 818: 805: 800: 798: 796: 792: 786: 784: 779: 775: 770: 766: 764: 760: 741: 738: 730: 726: 722: 719: 716: 711: 707: 703: 698: 694: 690: 685: 681: 677: 674: 671: 666: 662: 658: 653: 649: 629: 628: 627: 610: 600: 596: 591: 584: 577: 573: 568: 559: 554: 543: 538: 534: 526: 525: 524: 507: 504: 496: 492: 488: 485: 482: 477: 473: 469: 464: 460: 456: 451: 447: 443: 440: 437: 432: 428: 424: 419: 415: 395: 394: 393: 379: 374: 370: 366: 363: 360: 355: 351: 347: 342: 338: 315: 310: 306: 297: 293: 275: 270: 266: 242: 239: 231: 226: 222: 218: 213: 209: 205: 202: 199: 194: 190: 186: 181: 177: 163: 162: 161: 142: 138: 134: 131: 128: 123: 119: 115: 110: 106: 94: 90: 86: 78: 76: 74: 70: 66: 62: 58: 53: 51: 47: 43: 39: 35: 31: 23: 18: 1980: 1976: 1970: 1952:. Springer. 1949: 1926: 1922: 1897: 1892: 1883: 1847: 1811: 1802: 1793: 1776:, by Gauss' 1479:and for any 1380: 1376: 1372: 1368: 1364: 1358: 1206: 1201: 1169:-close to a 1136: 1125: 994: 983: 973: 887: 868: 864: 856: 851: 809: 787: 782: 773: 771: 767: 762: 758: 757:is called a 756: 625: 522: 295: 291: 257: 92: 88: 84: 82: 72: 54: 37: 33: 27: 1983:: 347–375. 1815:John Nash, 860:convex sets 791:Lagrangians 38:h-principle 30:mathematics 2012:Categories 1946:Gromov, M. 1927:-principle 1785:References 1410:such that 1171:Legendrian 79:Rough idea 1990:1111.2700 1510:⁡ 1464:− 1232:∞ 1139:homotopic 1132:holonomic 1108:α 1105:⁡ 1096:˙ 1084:α 1081:⁡ 1072:˙ 1043:α 969:Gauss map 936:↦ 913:θ 907:↦ 904:θ 835:≠ 720:… 675:… 638:Ψ 588:∂ 585:… 565:∂ 551:∂ 486:… 441:… 404:Ψ 364:… 203:… 171:Ψ 132:… 1948:(1986). 1219:smooth ( 1128:robotics 852:ordinary 822:′ 778:deformed 65:homotopy 1956:  1934:  772:A PDE 292:ƒ 258:where 85:ƒ 32:, the 1985:arXiv 1969:"The 1217:short 1954:ISBN 1932:ISBN 1604:The 1507:grad 1015:and 876:The 36:(or 1995:doi 1367:on 1273:in 1102:cos 1078:sin 87:on 28:In 2014:: 1993:. 1981:49 1979:. 1975:. 1499:, 1443:, 1204:. 1134:. 984:k, 838:0. 797:. 765:. 59:, 2003:. 1997:: 1987:: 1971:h 1962:. 1940:. 1925:h 1864:1 1860:C 1828:1 1824:C 1780:. 1762:2 1758:S 1735:2 1731:C 1704:2 1700:C 1677:3 1672:R 1648:2 1644:S 1621:1 1617:C 1601:. 1587:2 1583:S 1560:1 1556:C 1526:) 1521:t 1517:f 1513:( 1487:t 1467:f 1461:= 1456:1 1452:f 1431:f 1428:= 1423:0 1419:f 1396:t 1392:f 1381:x 1377:x 1375:( 1373:f 1369:R 1365:f 1321:1 1317:C 1294:1 1291:+ 1288:m 1283:R 1259:m 1255:M 1228:C 1200:- 1186:0 1182:C 1155:0 1151:C 1111:. 1093:y 1087:= 1069:x 1023:y 1003:x 944:n 940:z 933:z 925:( 910:n 884:. 832:) 829:x 826:( 819:f 742:0 739:= 736:) 731:N 727:y 723:, 717:, 712:2 708:y 704:, 699:1 695:y 691:, 686:m 682:u 678:, 672:, 667:2 663:u 659:, 654:1 650:u 646:( 611:. 601:k 597:j 592:u 578:1 574:j 569:u 560:f 555:k 544:= 539:j 535:y 508:0 505:= 502:) 497:N 493:y 489:, 483:, 478:2 474:y 470:, 465:1 461:y 457:, 452:m 448:u 444:, 438:, 433:2 429:u 425:, 420:1 416:u 412:( 380:. 375:N 371:y 367:, 361:, 356:2 352:y 348:, 343:1 339:y 316:k 311:f 307:J 296:k 276:k 271:f 267:J 243:0 240:= 237:) 232:k 227:f 223:J 219:, 214:m 210:u 206:, 200:, 195:2 191:u 187:, 182:1 178:u 174:( 148:) 143:m 139:u 135:, 129:, 124:2 120:u 116:, 111:1 107:u 103:( 93:k 89:R 73:C 24:.

Index


sphere eversion
mathematics
partial differential equations
partial differential relations
underdetermined
Yakov Eliashberg
Mikhail Gromov
homotopy
Whitney–Graustein theorem
deformed
Lagrangians
pseudo-holomorphic curves
convex sets

Whitney–Graustein theorem
turning number
winding number
universal covering space
Whitney–Graustein theorem
turning number
Gauss map
Stiefel manifolds
frame bundles
robotics
holonomic
homotopic
Legendrian
Nash embedding theorem
Nash–Kuiper theorem

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

↑