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Spectral triple

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90:, gives a K-cycle which encodes index-theoretic information. The local index formula expresses the pairing of the K-group of the manifold with this K-cycle in two ways: the 'analytic/global' side involves the usual trace on the Hilbert space and commutators of functions with the phase operator (which corresponds to the 'index' part of the index theorem), while the 'geometric/local' side involves the 134:
spectral triple is a spectral triple (A, H, D) such that a.D for any a in A has a compact resolvent which belongs to the class of L-operators for a fixed p (when A contains the identity operator on H, it is enough to require D in L(H)). When this condition is satisfied, the triple (A, H, D) is said
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context, an analogue of the Gromov-Hausdorff distance has been constructed on the space of metric spectral triples, allowing the discussion of the geometry of this space, and the construction of approximations of spectral triples by "simpler" (more regular, or finite dimensional) spectral triples.
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These observations are the foundations of the study of noncommutative metric geometry, which deals with the geometry of the space of quantum metric spaces, many of which being constructed using spectral triples whose Connes' metric induces the weak* topology on the underlying state space. In this
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structure, among others. In those cases the algebraic system of the 'functions' which expresses the underlying geometric object is no longer commutative, but one may able to find the space of square integrable spinors (or, sections of a Clifford module) on which the algebra acts, and the
82:, accompanied by the Dirac operator associated to the spin structure. From the knowledge of these objects one is able to recover the original manifold as a metric space: the manifold as a topological space is recovered as the spectrum of the algebra, while the (absolute value of) 127:-grading on H, such that the elements in A are even while D is odd with respect to this grading. One could also say that an even spectral triple is given by a quartet (A, H, D, γ) such that γ is a self adjoint unitary on H satisfying a γ = γ a for any a in A and D γ = - γ D. 1200: 1624:
Guided by this observation, it is natural to wonder what properties Connes' metric shares with Kantorovich's distance. In general, the topology induced by Connes' distance may not be Hausdorff, or give a finite diameter to the state space of the
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Rieffel worked out a necessary and sufficient condition on spectral triples (and more generally, on seminorms which play a role of analogue for Lipschitz seminorms) for Connes' distance to indeed induce the weak* topology on the state space of
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spectral triple is a spectral triple (A, H, D) accompanied with an anti-linear involution J on H, satisfying = 0 for a, b in A. In the even case it is usually assumed that J is even with respect to the grading on H.
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is a triple (A, H, D) consisting of a Hilbert space H, an algebra A of operators on H (usually closed under taking adjoints) and a densely defined self adjoint operator D satisfying ‖‖ < ∞ for any a ∈ A. An
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Extensions of the index theorem can be considered in cases, typically when one has an action of a group on the manifold, or when the manifold is endowed with a
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satisfying some algebraic conditions and give Hochschild / cyclic cohomology cocycles, which describe the above maps from K-theory to the integers.
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and commutators with the Dirac operator (which corresponds to the 'characteristic class integration' part of the index theorem).
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corresponding 'Dirac' operator on it satisfying certain boundedness of commutators implied by the pseudo-differential calculus.
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An invitation to noncommutative geometry. Lectures of the international workshop on noncommutative geometry, Tehran, Iran, 2005
165:(s) = Tr(b|D|) for each element b in the algebra B generated by δ(A) and δ() for positive integers n. They are related to the 2234:. University Lecture Series. Vol. 36. With a foreword by Yuri Manin. Providence, RI: American Mathematical Society. 2071:
When the spectral triple is finitely summable, one may write the above indexes using the (super) trace, and a product of
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Given a spectral triple (A, H, D), one can apply several important operations to it. The most fundamental one is the
49: 870: 1649:, whereas Kantorovich's metric always induces the weak* topology on the space of Radon probability measures over 1771: 831: 670: 32:
is a set of data which encodes a geometric phenomenon in an analytic way. The definition typically involves a
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when the elements in A and the operators of the form for a in A are in the domain of the iterates δ of δ.
962: 1195:{\displaystyle k(\mu ,\nu )=\sup\{|\int _{X}fd\mu -\int _{X}fd\nu |:f\in C(X),\mathrm {Lip} (f)\leq 1\},} 1895: 1738: 317: 86:
retains the metric. On the other hand, the phase part of the Dirac operator, in conjunction with the
37: 1289: 594:, that the restriction of this pseudo-metric to the pure states, i.e. the characters of the C*-algebra 202: 1676: 1628: 1324: 350: 254: 25: 724: 958: 591: 198: 954: 74:
A motivating example of spectral triple is given by the algebra of smooth functions on a compact
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Let δ(T) denote the commutator of |D| with an operator T on H. A spectral triple is said to be
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Moreover, Connes observed that this distance is bounded if, and only if, there exists a state
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D = F|D| of D into a self adjoint unitary operator F (the 'phase' of D) and a densely defined
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and sought its extension to 'noncommutative' spaces. Some authors refer to this notion as
2249: 2207: 1465:{\displaystyle \mathrm {Lip} (f)=\sup\{{\frac {|f(x)-f(y)|}{d(x,y)}}:x,y\in X,x\not =y\}.} 1205: 597: 62: 1652: 1517: 1497: 1477: 1234: 808: 778: 760: 650: 630: 573: 282: 83: 1918:
into integers by taking Fredholm index as follows. In the even case, each projection
2260: 2215: 802: 624: 300: 91: 75: 33: 2174: 2157: 536:{\displaystyle d(\varphi ,\psi )=\sup\{|\varphi (a)-\psi (a)|:a\in A,\|\|\leq 1\}.} 308: 304: 45: 41: 2218:. "Cyclic Theory, Bivariant K-Theory and the Bivariant Chern-Connes Character". 2112: 166: 21: 570:, and it may be zero between different states. Connes originally observed, for 961:
over a compact metric space, as introduced by Kantorovich during his study of
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A. Connes, H. Moscovici; The Local Index Formula in Noncommutative Geometry
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are two such probability measures, then Kantorovich's distance between
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This analogy is more than formal: in the case described above, where
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operator, endowed with supplemental structures. It was conceived by
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When a spectral triple (A, H, D) is p-summable, one may define its
173:. The collection of the poles of the analytic continuation of ζ 623:, whose space is naturally homeomorphic (when endowed with the 1231:
is the C*-algebra of complex valued continuous functions over
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induced by the Riemannian metric, when the spectral triple is
1887:{\displaystyle \left\{a\in A:\|\|\leq 1,\mu (a)=0\right\}} 2134:
A. Connes, Noncommutative Geometry, Academic Press, 1994
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This construction is reminiscent of the construction by
647:, recovers the path metric for a Riemannian metric over 161:(s) = Tr(|D|); more generally there are zeta functions ζ 2053: − 1)/4 gives an additive mapping from 1697:, namely: Connes' metric induced by a spectral triple 1813: 1774: 1741: 1703: 1679: 1655: 1631: 1584: 1540: 1520: 1500: 1494:
is a connected compact spin Riemannian manifold, and
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is the algebra of smooth functions over the manifold
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Noncommutative geometry, quantum fields and motives
2005:. In the odd case the eigenspace decomposition of 1886: 1799: 1760: 1727: 1689: 1661: 1641: 1613: 1570: 1526: 1506: 1486: 1464: 1315: 1278: 1243: 1223: 1194: 1041: 1015: 989: 942: 859: 817: 793: 769: 749: 713: 659: 639: 615: 582: 562: 535: 404: 363: 339: 291: 267: 243: 1735:topolgizes the weak* topology on the state space 1357: 1079: 781:acting on a dense subspace of the Hilbert space 442: 943:{\displaystyle \{a\in A:\|\|\leq 1,\mu (a)=0\}} 8: 1849: 1831: 1559: 1541: 1456: 1360: 1186: 1082: 937: 907: 889: 874: 592:connected, compact, spin Riemannian manifold 527: 518: 500: 445: 2220:Cyclic homology in non-commutative geometry 143:when e is of trace class for any t > 0. 2176:An introduction to noncommutative geometry 2130: 2128: 1800:{\displaystyle \mu \in S({\mathfrak {A}})} 860:{\displaystyle \mu \in S({\mathfrak {A}})} 714:{\displaystyle (C^{\infty }(X),\Gamma ,D)} 1812: 1788: 1787: 1773: 1749: 1748: 1740: 1702: 1681: 1680: 1678: 1654: 1633: 1632: 1630: 1585: 1583: 1539: 1519: 1499: 1479: 1398: 1366: 1363: 1334: 1332: 1293: 1291: 1256: 1236: 1207: 1160: 1131: 1116: 1094: 1085: 1056: 1028: 1002: 970: 872: 848: 847: 833: 810: 786: 762: 732: 726: 681: 672: 652: 632: 599: 575: 555: 480: 448: 419: 376: 355: 354: 352: 328: 327: 319: 284: 259: 258: 256: 218: 208: 2124: 1614:{\displaystyle \mathrm {Lip} (f)\leq 1} 1768:if, and only if, there exists a state 405:{\displaystyle \varphi ,\psi \in S(A)} 801:of square integrable sections of the 7: 2192:. Hackensack, NJ: World Scientific. 777:, and D is the closure of the usual 40:of operators on it and an unbounded 1789: 1750: 1682: 1634: 849: 356: 329: 260: 139:. A spectral triple is said to be 78:, acting on the Hilbert space of L- 2232:Arithmetic Noncommutative Geometry 1761:{\displaystyle S({\mathfrak {A}})} 1592: 1589: 1586: 1341: 1338: 1335: 1300: 1297: 1294: 1167: 1164: 1161: 997:is a compact metric space, and if 788: 733: 699: 682: 557: 371:, by setting, for any two states 340:{\displaystyle S({\mathfrak {A}})} 14: 2013:, and each invertible element in 1953:becomes a Fredholm operator from 1514:is the associated path metric on 1316:{\displaystyle \mathrm {Lip} (f)} 209:Connes' Metric on the state space 119:is an odd spectral triple with a 1990:defines an additive mapping of 1914:gives a map of the K-theory of 1690:{\displaystyle {\mathfrak {A}}} 1642:{\displaystyle {\mathfrak {A}}} 364:{\displaystyle {\mathfrak {A}}} 268:{\displaystyle {\mathfrak {A}}} 2099: + 1)-functional on 2095:). This can be encoded as a ( 2025: − 1)/4 from ( 1870: 1864: 1846: 1834: 1794: 1784: 1755: 1745: 1722: 1704: 1602: 1596: 1556: 1544: 1420: 1408: 1399: 1395: 1389: 1380: 1374: 1367: 1351: 1345: 1310: 1304: 1273: 1267: 1218: 1212: 1177: 1171: 1154: 1148: 1132: 1086: 1073: 1061: 984: 972: 963:Monge's transportation problem 957:of a distance on the space of 928: 922: 904: 892: 854: 844: 750:{\displaystyle C^{\infty }(X)} 744: 738: 708: 693: 687: 674: 610: 604: 515: 503: 481: 477: 471: 462: 456: 449: 436: 424: 399: 393: 334: 324: 238: 220: 1: 2049: + 1) u ( 2021: + 1) u ( 1669:--- which is weak* compact. 2017:gives a Fredholm operator ( 965:. Indeed, in that case, if 50:Atiyah-Singer index theorem 2283: 1571:{\displaystyle \|\|\leq 1} 959:Radon probability measures 550:can indeed take the value 251:is a spectral triple, and 1910:The self adjoint unitary 1279:{\displaystyle f\in C(X)} 1042:{\displaystyle \mu ,\nu } 1016:{\displaystyle \mu ,\nu } 205:|D| (the 'metric' part). 177:for b in B is called the 48:who was motivated by the 20:and related branches of 2267:Noncommutative geometry 2045: → Ind ( 1728:{\displaystyle (A,H,D)} 1251:, and for any function 794:{\displaystyle \Gamma } 563:{\displaystyle \infty } 244:{\displaystyle (A,H,D)} 18:noncommutative geometry 1977: → Ind  1940:under the grading and 1888: 1801: 1762: 1729: 1691: 1663: 1643: 1615: 1572: 1528: 1508: 1488: 1466: 1317: 1280: 1245: 1225: 1196: 1043: 1017: 991: 944: 861: 819: 795: 771: 751: 715: 661: 641: 617: 584: 564: 537: 406: 365: 341: 309:extended pseudo-metric 293: 269: 245: 2029: − 1) 1906:Pairing with K-theory 1889: 1802: 1763: 1730: 1692: 1664: 1644: 1616: 1573: 1529: 1509: 1489: 1467: 1318: 1281: 1246: 1226: 1197: 1044: 1018: 992: 990:{\displaystyle (X,d)} 945: 862: 820: 796: 772: 752: 716: 662: 642: 618: 585: 565: 538: 407: 366: 342: 294: 270: 246: 2083:) and commutator of 1811: 1772: 1739: 1701: 1677: 1653: 1629: 1582: 1538: 1518: 1498: 1478: 1331: 1290: 1255: 1235: 1224:{\displaystyle C(X)} 1206: 1055: 1027: 1001: 969: 871: 832: 809: 785: 761: 725: 671: 651: 631: 616:{\displaystyle C(X)} 598: 574: 554: 418: 375: 351: 318: 283: 255: 217: 117:even spectral triple 88:algebra of functions 26:mathematical physics 2184:Khalkhali, Masoud; 2173:Várilly, Joseph C. 2009:gives a grading on 867:such that the set: 199:polar decomposition 112:odd spectral triple 1884: 1807:such that the set 1797: 1758: 1725: 1687: 1659: 1639: 1611: 1568: 1524: 1504: 1484: 1462: 1325:Lipschitz seminorm 1313: 1276: 1241: 1221: 1192: 1039: 1013: 987: 940: 857: 815: 791: 767: 747: 711: 657: 637: 613: 580: 560: 533: 402: 361: 337: 289: 265: 241: 193:Important concepts 179:dimension spectrum 2241:978-0-8218-3833-4 2228:Marcolli, Matilde 2199:978-981-270-616-4 2186:Marcolli, Matilde 2162:Marcolli, Matilde 1662:{\displaystyle X} 1578:if, and only if, 1527:{\displaystyle X} 1507:{\displaystyle d} 1487:{\displaystyle X} 1424: 1244:{\displaystyle X} 818:{\displaystyle X} 770:{\displaystyle X} 660:{\displaystyle X} 640:{\displaystyle X} 583:{\displaystyle X} 292:{\displaystyle A} 203:positive operator 132:finitely summable 2274: 2253: 2223: 2211: 2180: 2169: 2144: 2141: 2135: 2132: 1893: 1891: 1890: 1885: 1883: 1879: 1806: 1804: 1803: 1798: 1793: 1792: 1767: 1765: 1764: 1759: 1754: 1753: 1734: 1732: 1731: 1726: 1696: 1694: 1693: 1688: 1686: 1685: 1668: 1666: 1665: 1660: 1648: 1646: 1645: 1640: 1638: 1637: 1620: 1618: 1617: 1612: 1595: 1577: 1575: 1574: 1569: 1533: 1531: 1530: 1525: 1513: 1511: 1510: 1505: 1493: 1491: 1490: 1485: 1471: 1469: 1468: 1463: 1425: 1423: 1403: 1402: 1370: 1364: 1344: 1322: 1320: 1319: 1314: 1303: 1285: 1283: 1282: 1277: 1250: 1248: 1247: 1242: 1230: 1228: 1227: 1222: 1201: 1199: 1198: 1193: 1170: 1135: 1121: 1120: 1099: 1098: 1089: 1048: 1046: 1045: 1040: 1022: 1020: 1019: 1014: 996: 994: 993: 988: 949: 947: 946: 941: 866: 864: 863: 858: 853: 852: 824: 822: 821: 816: 800: 798: 797: 792: 776: 774: 773: 768: 756: 754: 753: 748: 737: 736: 720: 718: 717: 712: 686: 685: 666: 664: 663: 658: 646: 644: 643: 638: 622: 620: 619: 614: 589: 587: 586: 581: 569: 567: 566: 561: 546:In general, the 542: 540: 539: 534: 484: 452: 411: 409: 408: 403: 370: 368: 367: 362: 360: 359: 346: 344: 343: 338: 333: 332: 298: 296: 295: 290: 274: 272: 271: 266: 264: 263: 250: 248: 247: 242: 171:Mellin transform 169:exp(-t|D|) by a 63:Fredholm modules 2282: 2281: 2277: 2276: 2275: 2273: 2272: 2271: 2257: 2256: 2242: 2226: 2214: 2200: 2183: 2172: 2156: 2153: 2148: 2147: 2142: 2138: 2133: 2126: 2121: 2109: 2059: 2037: + 1) 1996: 1989: 1983: 1969: 1959: 1952: 1946: 1939: 1932: 1908: 1896:totally bounded 1818: 1814: 1809: 1808: 1770: 1769: 1737: 1736: 1699: 1698: 1675: 1674: 1651: 1650: 1627: 1626: 1580: 1579: 1536: 1535: 1516: 1515: 1496: 1495: 1476: 1475: 1404: 1365: 1329: 1328: 1288: 1287: 1286:, we denote by 1253: 1252: 1233: 1232: 1204: 1203: 1112: 1090: 1053: 1052: 1025: 1024: 999: 998: 967: 966: 869: 868: 830: 829: 807: 806: 783: 782: 759: 758: 728: 723: 722: 677: 669: 668: 649: 648: 629: 628: 596: 595: 572: 571: 552: 551: 545: 416: 415: 373: 372: 349: 348: 316: 315: 281: 280: 253: 252: 215: 214: 211: 195: 176: 164: 160: 108: 72: 30:spectral triple 12: 11: 5: 2280: 2278: 2270: 2269: 2259: 2258: 2255: 2254: 2240: 2224: 2216:Cuntz, Joachim 2212: 2198: 2181: 2170: 2152: 2149: 2146: 2145: 2136: 2123: 2122: 2120: 2117: 2116: 2115: 2108: 2105: 2057: 1994: 1987: 1981: 1967: 1957: 1950: 1944: 1937: 1930: 1926:decomposes as 1907: 1904: 1882: 1878: 1875: 1872: 1869: 1866: 1863: 1860: 1857: 1854: 1851: 1848: 1845: 1842: 1839: 1836: 1833: 1830: 1827: 1824: 1821: 1817: 1796: 1791: 1786: 1783: 1780: 1777: 1757: 1752: 1747: 1744: 1724: 1721: 1718: 1715: 1712: 1709: 1706: 1684: 1658: 1636: 1610: 1607: 1604: 1601: 1598: 1594: 1591: 1588: 1567: 1564: 1561: 1558: 1555: 1552: 1549: 1546: 1543: 1523: 1503: 1483: 1461: 1458: 1455: 1452: 1449: 1446: 1443: 1440: 1437: 1434: 1431: 1428: 1422: 1419: 1416: 1413: 1410: 1407: 1401: 1397: 1394: 1391: 1388: 1385: 1382: 1379: 1376: 1373: 1369: 1362: 1359: 1356: 1353: 1350: 1347: 1343: 1340: 1337: 1312: 1309: 1306: 1302: 1299: 1296: 1275: 1272: 1269: 1266: 1263: 1260: 1240: 1220: 1217: 1214: 1211: 1191: 1188: 1185: 1182: 1179: 1176: 1173: 1169: 1166: 1163: 1159: 1156: 1153: 1150: 1147: 1144: 1141: 1138: 1134: 1130: 1127: 1124: 1119: 1115: 1111: 1108: 1105: 1102: 1097: 1093: 1088: 1084: 1081: 1078: 1075: 1072: 1069: 1066: 1063: 1060: 1038: 1035: 1032: 1012: 1009: 1006: 986: 983: 980: 977: 974: 939: 936: 933: 930: 927: 924: 921: 918: 915: 912: 909: 906: 903: 900: 897: 894: 891: 888: 885: 882: 879: 876: 856: 851: 846: 843: 840: 837: 814: 790: 779:Dirac operator 766: 746: 743: 740: 735: 731: 710: 707: 704: 701: 698: 695: 692: 689: 684: 680: 676: 656: 636: 625:weak* topology 612: 609: 606: 603: 579: 559: 532: 529: 526: 523: 520: 517: 514: 511: 508: 505: 502: 499: 496: 493: 490: 487: 483: 479: 476: 473: 470: 467: 464: 461: 458: 455: 451: 447: 444: 441: 438: 435: 432: 429: 426: 423: 401: 398: 395: 392: 389: 386: 383: 380: 358: 336: 331: 326: 323: 307:introduces an 288: 262: 240: 237: 234: 231: 228: 225: 222: 210: 207: 194: 191: 181:of (A, H, D). 174: 162: 158: 107: 104: 84:Dirac operator 71: 68: 13: 10: 9: 6: 4: 3: 2: 2279: 2268: 2265: 2264: 2262: 2251: 2247: 2243: 2237: 2233: 2229: 2225: 2221: 2217: 2213: 2209: 2205: 2201: 2195: 2191: 2187: 2182: 2178: 2177: 2171: 2167: 2163: 2159: 2158:Connes, Alain 2155: 2154: 2150: 2140: 2137: 2131: 2129: 2125: 2118: 2114: 2111: 2110: 2106: 2104: 2102: 2098: 2094: 2090: 2086: 2082: 2078: 2074: 2069: 2067: 2063: 2056: 2052: 2048: 2044: 2040: 2036: 2032: 2028: 2024: 2020: 2016: 2012: 2008: 2004: 2000: 1993: 1986: 1980: 1976: 1973:. Thus  1972: 1966: 1962: 1956: 1949: 1943: 1936: 1933: ⊕  1929: 1925: 1921: 1917: 1913: 1905: 1903: 1899: 1897: 1880: 1876: 1873: 1867: 1861: 1858: 1855: 1852: 1843: 1840: 1837: 1828: 1825: 1822: 1819: 1815: 1781: 1778: 1775: 1742: 1719: 1716: 1713: 1710: 1707: 1670: 1656: 1622: 1608: 1605: 1599: 1565: 1562: 1553: 1550: 1547: 1521: 1501: 1481: 1472: 1459: 1453: 1450: 1447: 1444: 1441: 1438: 1435: 1432: 1429: 1426: 1417: 1414: 1411: 1405: 1392: 1386: 1383: 1377: 1371: 1354: 1348: 1326: 1307: 1270: 1264: 1261: 1258: 1238: 1215: 1209: 1189: 1183: 1180: 1174: 1157: 1151: 1145: 1142: 1139: 1136: 1128: 1125: 1122: 1117: 1113: 1109: 1106: 1103: 1100: 1095: 1091: 1076: 1070: 1067: 1064: 1058: 1050: 1036: 1033: 1030: 1010: 1007: 1004: 981: 978: 975: 964: 960: 956: 951: 934: 931: 925: 919: 916: 913: 910: 901: 898: 895: 886: 883: 880: 877: 841: 838: 835: 826: 812: 804: 803:spinor bundle 780: 764: 741: 729: 705: 702: 696: 690: 678: 654: 634: 626: 607: 601: 593: 577: 549: 548:Connes metric 543: 530: 524: 521: 512: 509: 506: 497: 494: 491: 488: 485: 474: 468: 465: 459: 453: 439: 433: 430: 427: 421: 413: 396: 390: 387: 384: 381: 378: 321: 314: 310: 306: 302: 301:operator norm 286: 278: 235: 232: 229: 226: 223: 206: 204: 200: 192: 190: 187: 182: 180: 172: 168: 156: 155:zeta function 151: 149: 144: 142: 138: 133: 128: 126: 122: 118: 113: 105: 103: 100: 95: 93: 92:Dixmier trace 89: 85: 81: 77: 76:spin manifold 69: 67: 65: 64: 58: 57: 51: 47: 43: 39: 35: 34:Hilbert space 31: 27: 23: 19: 2231: 2219: 2189: 2175: 2165: 2139: 2100: 2096: 2092: 2091:(resp.  2088: 2084: 2080: 2079:(resp.  2076: 2072: 2070: 2065: 2061: 2054: 2050: 2046: 2042: 2038: 2034: 2030: 2026: 2022: 2018: 2014: 2010: 2006: 2002: 1998: 1991: 1984: 1978: 1974: 1970: 1964: 1960: 1954: 1947: 1941: 1934: 1927: 1923: 1919: 1915: 1911: 1909: 1900: 1671: 1623: 1473: 1051: 952: 950:is bounded. 827: 547: 544: 414: 212: 196: 185: 183: 178: 154: 152: 147: 145: 140: 136: 131: 129: 124: 120: 116: 111: 109: 96: 73: 60: 53: 46:Alain Connes 42:self-adjoint 29: 15: 2113:JLO cocycle 955:Kantorovich 313:state space 167:heat kernel 22:mathematics 2250:1081.58005 2208:1135.14002 2151:References 2064:) to  141:θ-summable 137:p-summable 106:Definition 70:Motivation 61:unbounded 54:unbounded 1862:μ 1853:≤ 1850:‖ 1832:‖ 1823:∈ 1779:∈ 1776:μ 1606:≤ 1563:≤ 1560:‖ 1542:‖ 1439:∈ 1384:− 1262:∈ 1181:≤ 1143:∈ 1129:ν 1114:∫ 1110:− 1107:μ 1092:∫ 1071:ν 1065:μ 1037:ν 1031:μ 1011:ν 1005:μ 920:μ 911:≤ 908:‖ 890:‖ 881:∈ 839:∈ 836:μ 789:Γ 734:∞ 700:Γ 683:∞ 558:∞ 522:≤ 519:‖ 501:‖ 492:∈ 469:ψ 466:− 454:φ 434:ψ 428:φ 388:∈ 385:ψ 379:φ 99:foliation 2261:Category 2230:(2005). 2188:(2005). 2107:See also 2041:. Thus 1451:≠ 721:, where 299:for the 56:K-cycles 1534:, then 311:on the 303:, then 277:closure 275:is the 148:regular 80:spinors 38:algebra 2248:  2238:  2206:  2196:  1202:where 305:Connes 135:to be 59:or as 2119:Notes 2087:with 2001:) to 805:over 627:) to 36:, an 2236:ISBN 2194:ISBN 2033:to ( 1323:its 186:real 28:, a 24:and 2246:Zbl 2204:Zbl 1963:to 1922:in 1894:is 1358:sup 1080:sup 443:sup 347:of 279:of 213:If 110:An 16:In 2263:: 2244:. 2202:. 2164:. 2160:; 2127:^ 2075:, 2068:. 1985:Fe 1948:Fe 1898:. 1621:. 1327:: 825:. 590:a 412:: 184:A 130:A 123:/2 66:. 2252:. 2222:. 2210:. 2179:. 2168:. 2101:A 2097:p 2093:u 2089:e 2085:F 2081:u 2077:e 2073:F 2066:Z 2062:A 2060:( 2058:1 2055:K 2051:F 2047:F 2043:u 2039:H 2035:F 2031:H 2027:F 2023:F 2019:F 2015:A 2011:H 2007:F 2003:Z 1999:A 1997:( 1995:0 1992:K 1988:0 1982:1 1979:e 1975:e 1971:H 1968:1 1965:e 1961:H 1958:0 1955:e 1951:0 1945:1 1942:e 1938:1 1935:e 1931:0 1928:e 1924:A 1920:e 1916:A 1912:F 1881:} 1877:0 1874:= 1871:) 1868:a 1865:( 1859:, 1856:1 1847:] 1844:a 1841:, 1838:D 1835:[ 1829:: 1826:A 1820:a 1816:{ 1795:) 1790:A 1785:( 1782:S 1756:) 1751:A 1746:( 1743:S 1723:) 1720:D 1717:, 1714:H 1711:, 1708:A 1705:( 1683:A 1657:X 1635:A 1609:1 1603:) 1600:f 1597:( 1593:p 1590:i 1587:L 1566:1 1557:] 1554:f 1551:, 1548:D 1545:[ 1522:X 1502:d 1482:X 1460:. 1457:} 1454:y 1448:x 1445:, 1442:X 1436:y 1433:, 1430:x 1427:: 1421:) 1418:y 1415:, 1412:x 1409:( 1406:d 1400:| 1396:) 1393:y 1390:( 1387:f 1381:) 1378:x 1375:( 1372:f 1368:| 1361:{ 1355:= 1352:) 1349:f 1346:( 1342:p 1339:i 1336:L 1311:) 1308:f 1305:( 1301:p 1298:i 1295:L 1274:) 1271:X 1268:( 1265:C 1259:f 1239:X 1219:) 1216:X 1213:( 1210:C 1190:, 1187:} 1184:1 1178:) 1175:f 1172:( 1168:p 1165:i 1162:L 1158:, 1155:) 1152:X 1149:( 1146:C 1140:f 1137:: 1133:| 1126:d 1123:f 1118:X 1104:d 1101:f 1096:X 1087:| 1083:{ 1077:= 1074:) 1068:, 1062:( 1059:k 1034:, 1008:, 985:) 982:d 979:, 976:X 973:( 938:} 935:0 932:= 929:) 926:a 923:( 917:, 914:1 905:] 902:a 899:, 896:D 893:[ 887:: 884:A 878:a 875:{ 855:) 850:A 845:( 842:S 813:X 765:X 745:) 742:X 739:( 730:C 709:) 706:D 703:, 697:, 694:) 691:X 688:( 679:C 675:( 655:X 635:X 611:) 608:X 605:( 602:C 578:X 531:. 528:} 525:1 516:] 513:a 510:, 507:D 504:[ 498:, 495:A 489:a 486:: 482:| 478:) 475:a 472:( 463:) 460:a 457:( 450:| 446:{ 440:= 437:) 431:, 425:( 422:d 400:) 397:A 394:( 391:S 382:, 357:A 335:) 330:A 325:( 322:S 287:A 261:A 239:) 236:D 233:, 230:H 227:, 224:A 221:( 175:b 163:b 159:D 157:ζ 125:Z 121:Z

Index

noncommutative geometry
mathematics
mathematical physics
Hilbert space
algebra
self-adjoint
Alain Connes
Atiyah-Singer index theorem
K-cycles
Fredholm modules
spin manifold
spinors
Dirac operator
algebra of functions
Dixmier trace
foliation
heat kernel
Mellin transform
polar decomposition
positive operator
closure
operator norm
Connes
extended pseudo-metric
state space
connected, compact, spin Riemannian manifold
weak* topology
Dirac operator
spinor bundle
Kantorovich

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