Knowledge (XXG)

Spectrum of a C*-algebra

Source 📝

534: 2451: 1536: 316: 1908:
on a complex vector space is algebraically equivalent to a topologically irreducible *-representation on a Hilbert space. Topologically irreducible *-representations on a Hilbert space are algebraically isomorphic if and only if they are unitarily
1657: 645: 137:
locally compact groups of type I and a decomposition theorem for arbitrary representations of separable locally compact groups of type I. The resulting duality theory for locally compact groups is however much weaker than the
737: 459: 1419: 1339: 1007: 1209: 374: 1083: 801: 537:
3-dimensional commutative C*-algebra and its ideals. Each of 8 ideals corresponds to a closed subset of discrete 3-points space (or to an open complement). Primitive ideals correspond to closed
229: 2974: 1843:
The result implies a far-reaching generalization of the structure of representations of separable type I C*-algebras and correspondingly of separable locally compact groups of type I.
3076: 2340: 1563: 1752:
locally compact group is of type I if and only if the Borel space is standard, i.e. is isomorphic (in the category of Borel spaces) to the underlying Borel space of a
2709: 154:
groups, both of which are complete invariants. That the dual is not a complete invariant is easily seen as the dual of any finite-dimensional full matrix algebra M
2003: 591: 2166: 1368:
which arises by considering the space of representations as a topological space with an appropriate pointwise convergence topology. More precisely, let
2714: 2487: 3061: 2293: 2148: 1921: 2124: 656: 2954: 408: 2807: 2605: 1531:{\displaystyle \langle \pi _{i}(x)\xi \mid \eta \rangle \to \langle \pi (x)\xi \mid \eta \rangle \quad \forall \xi ,\eta \in H_{n}\ x\in A.} 2802: 1291: 952: 2016: 1148: 2959: 2105: 1996: 331: 2777: 2375: 2746: 2020: 1038: 756: 2736: 2731: 2724: 2660: 2544: 2969: 2480: 2171: 2227: 311:{\displaystyle {\overline {X}}=\left\{\rho \in \operatorname {Prim} (A):\rho \supseteq \bigcap _{\pi \in X}\pi \right\}.} 2595: 2454: 2176: 2161: 1989: 3106: 2580: 2191: 3026: 513: 3081: 2979: 2859: 2436: 2196: 203:, where a primitive ideal is the kernel of a non-zero irreducible *-representation. The set of primitive ideals is a 2390: 2314: 42: 2575: 2431: 139: 3086: 2949: 2782: 2767: 2539: 2247: 1878: 1100:, other characterizations of the topology on the spectrum in terms of positive definite functions are desirable. 380: 143: 2668: 2181: 533: 3132: 2473: 2084: 750:) so is in fact primitive. For details of the proof, see the Dixmier reference. For a commutative C*-algebra, 2156: 3041: 3016: 2834: 2823: 2534: 2380: 538: 2892: 2882: 2877: 2585: 2411: 2355: 2319: 580: 550: 38: 922:) on the other hand is much larger. There are many inequivalent irreducible representations with kernel 2637: 119: 115: 1093:
The hull-kernel topology is easy to describe abstractly, but in practice for C*-algebras associated to
1108: 398:
Since unitarily equivalent representations have the same kernel, the map π ↩ ker(π) factors through a
3127: 3051: 3030: 2944: 2829: 2792: 2394: 1652:{\displaystyle \pi _{i}(x)\xi \to \pi (x)\xi \quad {\mbox{ normwise }}\forall \xi \in H_{n}\ x\in A.} 2854: 2590: 2360: 2298: 2012: 1677:
consisting of equivalence classes of representations whose underlying Hilbert space has dimension
96: 2984: 2913: 2844: 2688: 2650: 2385: 2252: 1862: 1852: 147: 127: 108: 92:
irreducible representation, thus excluding trivial (i.e. identically 0) representations on one-
3091: 3066: 2751: 2673: 2365: 1097: 1029: 204: 123: 104: 1407:
with the point-weak topology. In terms of convergence of nets, this topology is defined by π
3096: 2797: 2645: 2600: 2524: 2370: 2288: 2257: 2237: 2222: 2217: 2212: 2049: 1817: 1233: 502: 131: 50: 3071: 3056: 2964: 2927: 2923: 2887: 2849: 2787: 2772: 2741: 2683: 2642: 2629: 2554: 2496: 2232: 2186: 2134: 2129: 2100: 1981: 1866: 1802: 1094: 576: 192: 134: 2059: 3021: 3000: 2918: 2908: 2719: 2626: 2559: 2519: 2421: 2273: 2074: 1890: 640:{\displaystyle \operatorname {I} :X\cong \operatorname {Prim} (\operatorname {C} (X)).} 1877:
is regarded algebraically. For a ring an ideal is primitive if and only if it is the
3121: 2426: 2350: 2079: 2064: 2054: 1937: 1882: 816: 583: 573: 58: 2839: 2693: 2634: 2416: 2069: 2039: 1753: 558: 2465: 114:
One of the most important applications of this concept is to provide a notion of
3036: 2621: 2345: 2335: 2242: 2044: 1813: 1761: 180:
can be defined in several equivalent ways. We first define it in terms of the
2529: 2278: 2118: 2114: 2110: 1249: 512:
induced from the hull-kernel topology has other characterizations in terms of
399: 383:. As a consequence, it can be shown that there is a unique topology τ on Prim( 322: 22: 1215:
with ||Ο|| = 1, is the weak limit of states associated to representations in
2514: 2500: 1809: 1806: 1764:
for separable C*-algebras in the 1961 paper listed in the references below.
1745: 1741: 732:{\displaystyle \operatorname {I} (x)=\{f\in \operatorname {C} (X):f(x)=0\}.} 93: 1244:. By one of the basic theorems associated to the GNS construction, a state 454:{\displaystyle \operatorname {k} :{\hat {A}}\to \operatorname {Prim} (A).} 3101: 3046: 1126:. Then the following are equivalent for an irreducible representation π; 501:
The hull-kernel topology is an analogue for non-commutative rings of the
173: 1778:
if and only if the center of the von Neumann algebra generated by π(
1032:. For finite-dimensional C*-algebras, we also have the isomorphism 1786:
is of type I if and only if any separable factor representation of
1334:{\displaystyle \kappa :\operatorname {PureState} (A)\to {\hat {A}}} 1002:{\displaystyle A\cong \bigoplus _{e\in \operatorname {min} (A)}Ae,} 1904:
be a C*-algebra. Any algebraically irreducible representation of
1820:
are all of type I. Compact and abelian groups are also of type I.
532: 1913:
This is the Corollary of Theorem 2.9.5 of the Dixmier reference.
1770:. A non-degenerate *-representation π of a separable C*-algebra 1225:
The second condition means exactly that π is weakly contained in
1204:{\displaystyle f_{\xi }(x)=\langle \xi \mid \pi (x)\xi \rangle } 2469: 1985: 1920:
is a locally compact group, the topology on dual space of the
1279:
From the previous theorem one can easily prove the following;
946:
is isomorphic to a finite direct sum of full matrix algebras:
391:
with respect to τ is identical to the hull-kernel closure of
88:. We implicitly assume that irreducible representation means 369:{\displaystyle {\overline {\overline {X}}}={\overline {X}},} 1740:
is a topological space and thus can also be regarded as a
1790:
is a finite or countable multiple of an irreducible one.
1364:
There is yet another characterization of the topology on
1258:
is irreducible. Moreover, the mapping Îș : PureState(
1078:{\displaystyle {\hat {A}}\cong \operatorname {Prim} (A).} 796:{\displaystyle {\hat {A}}\cong \operatorname {Prim} (A).} 1705:
can be regarded as the quotient topological space of Irr
1609: 1566: 1422: 1345:
given by the GNS construction is continuous and open.
1294: 1151: 1041: 955: 759: 659: 594: 411: 334: 232: 1139:
Every state associated to π, that is one of the form
3009: 2993: 2937: 2901: 2870: 2816: 2760: 2702: 2659: 2614: 2568: 2507: 2404: 2328: 2307: 2266: 2205: 2147: 2093: 2028: 1396:) is the space of irreducible *-representations of 1236:is a recipe for associating states of a C*-algebra 3077:Spectral theory of ordinary differential equations 2341:Spectral theory of ordinary differential equations 1651: 1551:) is the same as the point-strong topology, i.e. π 1530: 1333: 1203: 1077: 1001: 795: 731: 639: 453: 368: 310: 122:. This dual object is suitable for formulating a 2975:Schröder–Bernstein theorems for operator algebras 1756:. Mackey called Borel spaces with this property 1111:of representations as is shown by the following: 942:is a finite-dimensional C*-algebra. It is known 76:and {0} which is invariant under all operators π( 1252:if and only if the associated representation π 2481: 1997: 1793:Examples of separable locally compact groups 846:) of compact operators. Thus as a set, Prim( 321:Hull-kernel closure is easily shown to be an 68:if, and only if, there is no closed subspace 8: 1893:it is primitive in the sense defined above. 1484: 1460: 1454: 1423: 1379:be the canonical Hilbert space of dimension 1198: 1174: 1107:is intimately connected with the concept of 723: 678: 541:. See details at the image description page. 2488: 2474: 2466: 2032: 2004: 1990: 1982: 1628: 1608: 1571: 1565: 1507: 1430: 1421: 1320: 1319: 1293: 1156: 1150: 1043: 1042: 1040: 1016:) are the minimal central projections of 966: 954: 761: 760: 758: 658: 593: 545:The spectrum of a commutative C*-algebra 419: 418: 410: 353: 335: 333: 285: 233: 231: 2294:Group algebra of a locally compact group 1978:, The University of Chicago Press, 1955. 1962:Les C*-algĂšbres et leurs reprĂ©sentations 1955:Les C*-algĂšbres et leurs reprĂ©sentations 1953:, North-Holland, 1977 (a translation of 1722:. The piecing together of the various 1698:is continuous and open. In particular, 1089:Other characterizations of the spectrum 107:; this is similar to the notion of the 1971:, Annals of Mathematics, vol 73, 1961. 1889:, an ideal is algebraically primitive 1885:. It turns out that for a C*-algebra 1541:It turns out that this topology on Irr 2808:Spectral theory of normal C*-algebras 2606:Spectral theory of normal C*-algebras 7: 2803:Spectral theory of compact operators 1782:) is one-dimensional. A C*-algebra 815:be a separable infinite-dimensional 1976:The Theory of Group Representations 807:The C*-algebra of bounded operators 379:and it can be shown to satisfy the 99:. As explained below, the spectrum 2955:Cohen–Hewitt factorization theorem 1865:, we can also consider the set of 1615: 1488: 687: 660: 616: 595: 412: 219:is a set of primitive ideals, its 215:). This is defined as follows: If 14: 2960:Extensions of symmetric operators 1024:is canonically isomorphic to min( 746:) is a closed maximal ideal in C( 387:) such that the closure of a set 2778:Positive operator-valued measure 2450: 2449: 2376:Topological quantum field theory 1760:. This conjecture was proved by 827:) has two norm-closed *-ideals: 3062:Rayleigh–Faber–Krahn inequality 1754:complete separable metric space 1607: 1487: 834: = {0} and the ideal 1601: 1595: 1589: 1583: 1577: 1472: 1466: 1457: 1442: 1436: 1325: 1316: 1313: 1307: 1192: 1186: 1168: 1162: 1129:The equivalence class of π in 1069: 1063: 1048: 985: 979: 934:Finite-dimensional C*-algebras 787: 781: 766: 714: 708: 699: 693: 672: 666: 631: 628: 622: 613: 498:). This is indeed a topology. 445: 439: 430: 424: 269: 263: 164:) consists of a single point. 1: 2970:Limiting absorption principle 2172:Uniform boundedness principle 1372:be a cardinal number and let 911:)) is a non-Hausdorff space. 873:} is a closed subset of Prim( 557:(not to be confused with the 2596:Singular value decomposition 1715:) under unitary equivalence. 358: 345: 341: 238: 3027:Hearing the shape of a drum 2710:Decomposition of a spectrum 1847:Algebraic primitive spectra 930:) or with kernel {0}. 650:This mapping is defined by 568:). In particular, suppose 3149: 2615:Special Elements/Operators 2315:Invariant subspace problem 1850: 1744:. A famous conjecture of 1729:can be quite complicated. 468:to define the topology on 187:The primitive spectrum of 144:compact topological groups 3087:Superstrong approximation 2950:Banach algebra cohomology 2783:Projection-valued measure 2768:Borel functional calculus 2540:Projection-valued measure 2445: 2035: 1964:, Gauthier-Villars, 1969. 1835:is smooth if and only if 1103:In fact, the topology on 381:Kuratowski closure axioms 2679:Spectrum of a C*-algebra 2550:Spectrum of a C*-algebra 2284:Spectrum of a C*-algebra 3107:Wiener–Khinchin theorem 3042:Kuznetsov trace formula 3017:Almost Mathieu operator 2835:Banach function algebra 2824:Amenable Banach algebra 2581:Gelfand–Naimark theorem 2535:Noncommutative topology 2381:Noncommutative geometry 1681:. The canonical map Irr 529:Commutative C*-algebras 505:for commutative rings. 3082:Sturm–Liouville theory 2980:Sherman–Takeda theorem 2860:Tomita–Takesaki theory 2635:Hermitian/Self-adjoint 2586:Gelfand representation 2437:Tomita–Takesaki theory 2412:Approximation property 2356:Calculus of variations 1816:Lie groups. Thus the 1733:Mackey–Borel structure 1653: 1532: 1335: 1240:to representations of 1205: 1079: 1003: 797: 733: 641: 542: 455: 370: 312: 2576:Gelfand–Mazur theorem 2432:Banach–Mazur distance 2395:Generalized functions 1776:factor representation 1654: 1533: 1336: 1276:is a surjective map. 1206: 1133:is in the closure of 1080: 1004: 798: 734: 642: 536: 456: 371: 313: 140:Tannaka–Krein duality 120:locally compact group 45:*-representations of 3052:Proto-value function 3031:Dirichlet eigenvalue 2945:Abstract index group 2830:Approximate identity 2793:Rigged Hilbert space 2669:Krein–Rutman theorem 2515:Involution/*-algebra 2177:Kakutani fixed-point 2162:Riesz representation 1611: normwise  1564: 1420: 1413:→ π; if and only if 1292: 1149: 1039: 953: 757: 657: 592: 564:of the Banach space 409: 332: 230: 209:hull-kernel topology 150:for locally compact 103:is also naturally a 28:dual of a C*-algebra 19:In mathematics, the 16:Mathematical concept 2855:Von Neumann algebra 2591:Polar decomposition 2361:Functional calculus 2320:Mahler's conjecture 2299:Von Neumann algebra 2013:Functional analysis 1857:Since a C*-algebra 1812:and connected real 1801:) is of type I are 1557:→ π if and only if 1020:. The spectrum of 579:. Then there is a 549:coincides with the 482:are inverse images 478:. The open sets of 325:operation, that is 221:hull-kernel closure 39:unitary equivalence 2985:Unbounded operator 2914:Essential spectrum 2893:Schur–Horn theorem 2883:Bauer–Fike theorem 2878:Alon–Boppana bound 2871:Finite-Dimensional 2845:Nuclear C*-algebra 2689:Spectral asymmetry 2386:Riemann hypothesis 2085:Topological vector 1969:Type I C*-algebras 1853:Primitive spectrum 1649: 1613: 1528: 1331: 1201: 1098:topological groups 1075: 999: 989: 793: 729: 637: 543: 490:) of open subsets 451: 366: 308: 296: 182:primitive spectrum 168:Primitive spectrum 148:Pontryagin duality 128:Plancherel theorem 109:spectrum of a ring 3115: 3114: 3092:Transfer operator 3067:Spectral geometry 2752:Spectral abscissa 2732:Approximate point 2674:Normal eigenvalue 2463: 2462: 2366:Integral operator 2143: 2142: 1818:Heisenberg groups 1673:be the subset of 1636: 1612: 1515: 1328: 1051: 1030:discrete topology 962: 769: 427: 361: 348: 344: 281: 241: 213:Jacobson topology 205:topological space 124:Fourier transform 105:topological space 3140: 3097:Transform theory 2817:Special algebras 2798:Spectral theorem 2761:Spectral Theorem 2601:Spectral theorem 2490: 2483: 2476: 2467: 2453: 2452: 2371:Jones polynomial 2289:Operator algebra 2033: 2006: 1999: 1992: 1983: 1922:group C*-algebra 1867:primitive ideals 1748:proposed that a 1658: 1656: 1655: 1650: 1634: 1633: 1632: 1614: 1610: 1576: 1575: 1537: 1535: 1534: 1529: 1513: 1512: 1511: 1435: 1434: 1340: 1338: 1337: 1332: 1330: 1329: 1321: 1234:GNS construction 1210: 1208: 1207: 1202: 1161: 1160: 1109:weak containment 1084: 1082: 1081: 1076: 1053: 1052: 1044: 1008: 1006: 1005: 1000: 988: 914:The spectrum of 884:The closure of { 802: 800: 799: 794: 771: 770: 762: 738: 736: 735: 730: 646: 644: 643: 638: 508:The topology on 503:Zariski topology 460: 458: 457: 452: 429: 428: 420: 375: 373: 372: 367: 362: 354: 349: 337: 336: 317: 315: 314: 309: 304: 300: 295: 242: 234: 193:primitive ideals 51:*-representation 37:, is the set of 3148: 3147: 3143: 3142: 3141: 3139: 3138: 3137: 3133:Spectral theory 3118: 3117: 3116: 3111: 3072:Spectral method 3057:Ramanujan graph 3005: 2989: 2965:Fredholm theory 2933: 2928:Shilov boundary 2924:Structure space 2902:Generalizations 2897: 2888:Numerical range 2866: 2850:Uniform algebra 2812: 2788:Riesz projector 2773:Min-max theorem 2756: 2742:Direct integral 2698: 2684:Spectral radius 2655: 2610: 2564: 2555:Spectral radius 2503: 2497:Spectral theory 2494: 2464: 2459: 2441: 2405:Advanced topics 2400: 2324: 2303: 2262: 2228:Hilbert–Schmidt 2201: 2192:Gelfand–Naimark 2139: 2089: 2024: 2010: 1946: 1855: 1849: 1735: 1727: 1710: 1703: 1696: 1686: 1671: 1624: 1567: 1562: 1561: 1556: 1546: 1503: 1426: 1418: 1417: 1412: 1405: 1391: 1377: 1362: 1355: 1290: 1289: 1275: 1257: 1152: 1147: 1146: 1122:be a subset of 1095:locally compact 1091: 1037: 1036: 951: 950: 936: 890: 860: 833: 809: 755: 754: 655: 654: 590: 589: 577:Hausdorff space 531: 526: 464:We use the map 407: 406: 330: 329: 250: 246: 228: 227: 170: 159: 118:object for any 72:different from 17: 12: 11: 5: 3146: 3144: 3136: 3135: 3130: 3120: 3119: 3113: 3112: 3110: 3109: 3104: 3099: 3094: 3089: 3084: 3079: 3074: 3069: 3064: 3059: 3054: 3049: 3044: 3039: 3034: 3024: 3022:Corona theorem 3019: 3013: 3011: 3007: 3006: 3004: 3003: 3001:Wiener algebra 2997: 2995: 2991: 2990: 2988: 2987: 2982: 2977: 2972: 2967: 2962: 2957: 2952: 2947: 2941: 2939: 2935: 2934: 2932: 2931: 2921: 2919:Pseudospectrum 2916: 2911: 2909:Dirac spectrum 2905: 2903: 2899: 2898: 2896: 2895: 2890: 2885: 2880: 2874: 2872: 2868: 2867: 2865: 2864: 2863: 2862: 2852: 2847: 2842: 2837: 2832: 2826: 2820: 2818: 2814: 2813: 2811: 2810: 2805: 2800: 2795: 2790: 2785: 2780: 2775: 2770: 2764: 2762: 2758: 2757: 2755: 2754: 2749: 2744: 2739: 2734: 2729: 2728: 2727: 2722: 2717: 2706: 2704: 2700: 2699: 2697: 2696: 2691: 2686: 2681: 2676: 2671: 2665: 2663: 2657: 2656: 2654: 2653: 2648: 2640: 2632: 2624: 2618: 2616: 2612: 2611: 2609: 2608: 2603: 2598: 2593: 2588: 2583: 2578: 2572: 2570: 2566: 2565: 2563: 2562: 2560:Operator space 2557: 2552: 2547: 2542: 2537: 2532: 2527: 2522: 2520:Banach algebra 2517: 2511: 2509: 2508:Basic concepts 2505: 2504: 2495: 2493: 2492: 2485: 2478: 2470: 2461: 2460: 2458: 2457: 2446: 2443: 2442: 2440: 2439: 2434: 2429: 2424: 2422:Choquet theory 2419: 2414: 2408: 2406: 2402: 2401: 2399: 2398: 2388: 2383: 2378: 2373: 2368: 2363: 2358: 2353: 2348: 2343: 2338: 2332: 2330: 2326: 2325: 2323: 2322: 2317: 2311: 2309: 2305: 2304: 2302: 2301: 2296: 2291: 2286: 2281: 2276: 2274:Banach algebra 2270: 2268: 2264: 2263: 2261: 2260: 2255: 2250: 2245: 2240: 2235: 2230: 2225: 2220: 2215: 2209: 2207: 2203: 2202: 2200: 2199: 2197:Banach–Alaoglu 2194: 2189: 2184: 2179: 2174: 2169: 2164: 2159: 2153: 2151: 2145: 2144: 2141: 2140: 2138: 2137: 2132: 2127: 2125:Locally convex 2122: 2108: 2103: 2097: 2095: 2091: 2090: 2088: 2087: 2082: 2077: 2072: 2067: 2062: 2057: 2052: 2047: 2042: 2036: 2030: 2026: 2025: 2011: 2009: 2008: 2001: 1994: 1986: 1980: 1979: 1972: 1965: 1958: 1945: 1942: 1936:, named after 1932:is called the 1911: 1910: 1891:if and only if 1848: 1845: 1841: 1840: 1831:is separable, 1734: 1731: 1725: 1717: 1716: 1706: 1701: 1694: 1682: 1669: 1660: 1659: 1648: 1645: 1642: 1639: 1631: 1627: 1623: 1620: 1617: 1606: 1603: 1600: 1597: 1594: 1591: 1588: 1585: 1582: 1579: 1574: 1570: 1552: 1542: 1539: 1538: 1527: 1524: 1521: 1518: 1510: 1506: 1502: 1499: 1496: 1493: 1490: 1486: 1483: 1480: 1477: 1474: 1471: 1468: 1465: 1462: 1459: 1456: 1453: 1450: 1447: 1444: 1441: 1438: 1433: 1429: 1425: 1408: 1403: 1387: 1375: 1361: 1351: 1348: 1347: 1346: 1343: 1342: 1341: 1327: 1324: 1318: 1315: 1312: 1309: 1306: 1303: 1300: 1297: 1271: 1253: 1223: 1222: 1221: 1220: 1213: 1212: 1211: 1200: 1197: 1194: 1191: 1188: 1185: 1182: 1179: 1176: 1173: 1170: 1167: 1164: 1159: 1155: 1141: 1140: 1137: 1090: 1087: 1086: 1085: 1074: 1071: 1068: 1065: 1062: 1059: 1056: 1050: 1047: 1010: 1009: 998: 995: 992: 987: 984: 981: 978: 975: 972: 969: 965: 961: 958: 935: 932: 901: 900: 888: 882: 858: 831: 808: 805: 804: 803: 792: 789: 786: 783: 780: 777: 774: 768: 765: 740: 739: 728: 725: 722: 719: 716: 713: 710: 707: 704: 701: 698: 695: 692: 689: 686: 683: 680: 677: 674: 671: 668: 665: 662: 648: 647: 636: 633: 630: 627: 624: 621: 618: 615: 612: 609: 606: 603: 600: 597: 530: 527: 525: 522: 462: 461: 450: 447: 444: 441: 438: 435: 432: 426: 423: 417: 414: 377: 376: 365: 360: 357: 352: 347: 343: 340: 319: 318: 307: 303: 299: 294: 291: 288: 284: 280: 277: 274: 271: 268: 265: 262: 259: 256: 253: 249: 245: 240: 237: 191:is the set of 169: 166: 155: 21:spectrum of a 15: 13: 10: 9: 6: 4: 3: 2: 3145: 3134: 3131: 3129: 3126: 3125: 3123: 3108: 3105: 3103: 3100: 3098: 3095: 3093: 3090: 3088: 3085: 3083: 3080: 3078: 3075: 3073: 3070: 3068: 3065: 3063: 3060: 3058: 3055: 3053: 3050: 3048: 3045: 3043: 3040: 3038: 3035: 3032: 3028: 3025: 3023: 3020: 3018: 3015: 3014: 3012: 3008: 3002: 2999: 2998: 2996: 2992: 2986: 2983: 2981: 2978: 2976: 2973: 2971: 2968: 2966: 2963: 2961: 2958: 2956: 2953: 2951: 2948: 2946: 2943: 2942: 2940: 2938:Miscellaneous 2936: 2929: 2925: 2922: 2920: 2917: 2915: 2912: 2910: 2907: 2906: 2904: 2900: 2894: 2891: 2889: 2886: 2884: 2881: 2879: 2876: 2875: 2873: 2869: 2861: 2858: 2857: 2856: 2853: 2851: 2848: 2846: 2843: 2841: 2838: 2836: 2833: 2831: 2827: 2825: 2822: 2821: 2819: 2815: 2809: 2806: 2804: 2801: 2799: 2796: 2794: 2791: 2789: 2786: 2784: 2781: 2779: 2776: 2774: 2771: 2769: 2766: 2765: 2763: 2759: 2753: 2750: 2748: 2745: 2743: 2740: 2738: 2735: 2733: 2730: 2726: 2723: 2721: 2718: 2716: 2713: 2712: 2711: 2708: 2707: 2705: 2703:Decomposition 2701: 2695: 2692: 2690: 2687: 2685: 2682: 2680: 2677: 2675: 2672: 2670: 2667: 2666: 2664: 2662: 2658: 2652: 2649: 2647: 2644: 2641: 2639: 2636: 2633: 2631: 2628: 2625: 2623: 2620: 2619: 2617: 2613: 2607: 2604: 2602: 2599: 2597: 2594: 2592: 2589: 2587: 2584: 2582: 2579: 2577: 2574: 2573: 2571: 2567: 2561: 2558: 2556: 2553: 2551: 2548: 2546: 2543: 2541: 2538: 2536: 2533: 2531: 2528: 2526: 2523: 2521: 2518: 2516: 2513: 2512: 2510: 2506: 2502: 2498: 2491: 2486: 2484: 2479: 2477: 2472: 2471: 2468: 2456: 2448: 2447: 2444: 2438: 2435: 2433: 2430: 2428: 2427:Weak topology 2425: 2423: 2420: 2418: 2415: 2413: 2410: 2409: 2407: 2403: 2396: 2392: 2389: 2387: 2384: 2382: 2379: 2377: 2374: 2372: 2369: 2367: 2364: 2362: 2359: 2357: 2354: 2352: 2351:Index theorem 2349: 2347: 2344: 2342: 2339: 2337: 2334: 2333: 2331: 2327: 2321: 2318: 2316: 2313: 2312: 2310: 2308:Open problems 2306: 2300: 2297: 2295: 2292: 2290: 2287: 2285: 2282: 2280: 2277: 2275: 2272: 2271: 2269: 2265: 2259: 2256: 2254: 2251: 2249: 2246: 2244: 2241: 2239: 2236: 2234: 2231: 2229: 2226: 2224: 2221: 2219: 2216: 2214: 2211: 2210: 2208: 2204: 2198: 2195: 2193: 2190: 2188: 2185: 2183: 2180: 2178: 2175: 2173: 2170: 2168: 2165: 2163: 2160: 2158: 2155: 2154: 2152: 2150: 2146: 2136: 2133: 2131: 2128: 2126: 2123: 2120: 2116: 2112: 2109: 2107: 2104: 2102: 2099: 2098: 2096: 2092: 2086: 2083: 2081: 2078: 2076: 2073: 2071: 2068: 2066: 2063: 2061: 2058: 2056: 2053: 2051: 2048: 2046: 2043: 2041: 2038: 2037: 2034: 2031: 2027: 2022: 2018: 2014: 2007: 2002: 2000: 1995: 1993: 1988: 1987: 1984: 1977: 1973: 1970: 1966: 1963: 1960:J. Dixmier, 1959: 1956: 1952: 1948: 1947: 1943: 1941: 1939: 1938:J. M. G. Fell 1935: 1934:Fell topology 1931: 1927: 1923: 1919: 1914: 1907: 1903: 1899: 1896: 1895: 1894: 1892: 1888: 1884: 1883:simple module 1880: 1876: 1872: 1868: 1864: 1860: 1854: 1846: 1844: 1839:is of type I. 1838: 1834: 1830: 1826: 1823: 1822: 1821: 1819: 1815: 1811: 1808: 1804: 1800: 1797:such that C*( 1796: 1791: 1789: 1785: 1781: 1777: 1773: 1769: 1765: 1763: 1759: 1755: 1751: 1747: 1743: 1739: 1732: 1730: 1728: 1721: 1714: 1709: 1704: 1697: 1690: 1685: 1680: 1676: 1672: 1665: 1662: 1661: 1646: 1643: 1640: 1637: 1629: 1625: 1621: 1618: 1604: 1598: 1592: 1586: 1580: 1572: 1568: 1560: 1559: 1558: 1555: 1550: 1545: 1525: 1522: 1519: 1516: 1508: 1504: 1500: 1497: 1494: 1491: 1481: 1478: 1475: 1469: 1463: 1451: 1448: 1445: 1439: 1431: 1427: 1416: 1415: 1414: 1411: 1406: 1399: 1395: 1390: 1384: 1382: 1378: 1371: 1367: 1359: 1354: 1350:The space Irr 1349: 1344: 1322: 1310: 1304: 1301: 1298: 1295: 1288: 1287: 1285: 1282: 1281: 1280: 1277: 1274: 1269: 1265: 1261: 1256: 1251: 1247: 1243: 1239: 1235: 1230: 1228: 1218: 1214: 1195: 1189: 1183: 1180: 1177: 1171: 1165: 1157: 1153: 1145: 1144: 1143: 1142: 1138: 1136: 1132: 1128: 1127: 1125: 1121: 1117: 1114: 1113: 1112: 1110: 1106: 1101: 1099: 1096: 1088: 1072: 1066: 1060: 1057: 1054: 1045: 1035: 1034: 1033: 1031: 1027: 1023: 1019: 1015: 996: 993: 990: 982: 976: 973: 970: 967: 963: 959: 956: 949: 948: 947: 945: 941: 933: 931: 929: 925: 921: 917: 912: 910: 906: 898: 894: 887: 883: 880: 876: 872: 868: 867: 866: 864: 857: 853: 849: 845: 841: 838: =  837: 830: 826: 822: 818: 817:Hilbert space 814: 806: 790: 784: 778: 775: 772: 763: 753: 752: 751: 749: 745: 726: 720: 717: 711: 705: 702: 696: 690: 684: 681: 675: 669: 663: 653: 652: 651: 634: 625: 619: 610: 607: 604: 601: 598: 588: 587: 586: 585: 584:homeomorphism 582: 578: 575: 571: 567: 563: 560: 556: 552: 548: 540: 535: 528: 523: 521: 519: 515: 511: 506: 504: 499: 497: 493: 489: 485: 481: 477: 473: 471: 467: 448: 442: 436: 433: 421: 415: 405: 404: 403: 401: 396: 394: 390: 386: 382: 363: 355: 350: 338: 328: 327: 326: 324: 305: 301: 297: 292: 289: 286: 282: 278: 275: 272: 266: 260: 257: 254: 251: 247: 243: 235: 226: 225: 224: 222: 218: 214: 210: 206: 202: 198: 194: 190: 185: 183: 179: 175: 167: 165: 163: 158: 153: 149: 145: 141: 136: 133: 129: 125: 121: 117: 112: 110: 106: 102: 98: 95: 91: 87: 83: 79: 75: 71: 67: 63: 60: 59:Hilbert space 56: 52: 48: 44: 40: 36: 32: 29: 25: 24: 3010:Applications 2840:Disk algebra 2694:Spectral gap 2678: 2569:Main results 2549: 2417:Balanced set 2391:Distribution 2329:Applications 2283: 2182:Krein–Milman 2167:Closed graph 1975: 1968: 1961: 1954: 1950: 1949:J. Dixmier, 1933: 1929: 1925: 1917: 1915: 1912: 1905: 1901: 1897: 1886: 1874: 1870: 1858: 1856: 1842: 1836: 1832: 1828: 1824: 1798: 1794: 1792: 1787: 1783: 1779: 1775: 1771: 1767: 1766: 1757: 1749: 1737: 1736: 1723: 1719: 1718: 1712: 1707: 1699: 1692: 1688: 1683: 1678: 1674: 1667: 1663: 1553: 1548: 1543: 1540: 1409: 1401: 1397: 1393: 1388: 1385: 1380: 1373: 1369: 1365: 1363: 1357: 1352: 1286:The mapping 1283: 1278: 1272: 1267: 1263: 1259: 1254: 1245: 1241: 1237: 1231: 1226: 1224: 1216: 1134: 1130: 1123: 1119: 1115: 1104: 1102: 1092: 1025: 1021: 1017: 1013: 1011: 943: 939: 937: 927: 923: 919: 915: 913: 908: 904: 902: 896: 892: 885: 878: 874: 870: 862: 855: 851: 847: 843: 839: 835: 828: 824: 820: 812: 810: 747: 743: 741: 649: 569: 565: 561: 554: 551:Gelfand dual 546: 544: 517: 509: 507: 500: 495: 491: 487: 483: 479: 475: 474: 472:as follows: 469: 465: 463: 397: 392: 388: 384: 378: 320: 220: 216: 212: 208: 200: 196: 188: 186: 181: 177: 171: 161: 156: 151: 113: 100: 89: 85: 81: 77: 73: 69: 65: 61: 54: 46: 41:classes of 34: 30: 27: 20: 18: 3128:C*-algebras 3037:Heat kernel 2737:Compression 2622:Isospectral 2346:Heat kernel 2336:Hardy space 2243:Trace class 2157:Hahn–Banach 2119:Topological 1974:G. Mackey, 1951:C*-Algebras 1909:equivalent. 1879:annihilator 1814:semi-simple 1762:James Glimm 1742:Borel space 1266:defined by 1028:) with the 854:)) = { 142:theory for 94:dimensional 66:irreducible 43:irreducible 3122:Categories 2715:Continuous 2530:C*-algebra 2525:B*-algebra 2279:C*-algebra 2094:Properties 1967:J. Glimm, 1944:References 1851:See also: 1810:Lie groups 1768:Definition 1012:where min( 903:Thus Prim( 891:} is Prim( 539:singletons 476:Definition 400:surjective 323:idempotent 132:unimodular 33:, denoted 23:C*-algebra 2501:-algebras 2253:Unbounded 2248:Transpose 2206:Operators 2135:Separable 2130:Reflexive 2115:Algebraic 2101:Barrelled 1807:nilpotent 1803:connected 1750:separable 1746:G. Mackey 1641:∈ 1622:∈ 1619:ξ 1616:∀ 1605:ξ 1593:π 1590:→ 1587:ξ 1569:π 1520:∈ 1501:∈ 1498:η 1492:ξ 1489:∀ 1485:⟩ 1482:η 1479:∣ 1476:ξ 1464:π 1461:⟨ 1458:→ 1455:⟩ 1452:η 1449:∣ 1446:ξ 1428:π 1424:⟨ 1326:^ 1317:→ 1305:⁡ 1302:PureState 1296:κ 1199:⟩ 1196:ξ 1184:π 1181:∣ 1178:ξ 1175:⟨ 1158:ξ 1061:⁡ 1055:≅ 1049:^ 977:⁡ 971:∈ 964:⨁ 960:≅ 779:⁡ 773:≅ 767:^ 691:⁡ 685:∈ 664:⁡ 620:⁡ 611:⁡ 605:≅ 437:⁡ 431:→ 425:^ 359:¯ 346:¯ 342:¯ 298:π 290:∈ 287:π 283:⋂ 279:⊇ 276:ρ 261:⁡ 255:∈ 252:ρ 239:¯ 207:with the 135:separable 3102:Weyl law 3047:Lax pair 2994:Examples 2828:With an 2747:Discrete 2725:Residual 2661:Spectrum 2646:operator 2638:operator 2630:operator 2545:Spectrum 2455:Category 2267:Algebras 2149:Theorems 2106:Complete 2075:Schwartz 2021:glossary 1873:, where 938:Suppose 524:Examples 494:of Prim( 174:topology 90:non-null 2643:Unitary 2258:Unitary 2238:Nuclear 2223:Compact 2218:Bounded 2213:Adjoint 2187:Min–max 2080:Sobolev 2065:Nuclear 2055:Hilbert 2050:FrĂ©chet 2015: ( 1900:. Let 1898:Theorem 1825:Theorem 1805:(real) 1664:Theorem 1284:Theorem 1116:Theorem 865:}. Now 861:,  581:natural 574:compact 152:abelian 80:) with 2627:Normal 2233:Normal 2070:Orlicz 2060:Hölder 2040:Banach 2029:Spaces 2017:topics 1758:smooth 1720:Remark 1666:. Let 1635:  1514:  1118:. Let 514:states 126:and a 97:spaces 2720:Point 2045:Besov 1928:) of 1881:of a 1861:is a 1827:. If 1774:is a 572:is a 199:) of 195:Prim( 57:on a 53:π of 2651:Unit 2499:and 2393:(or 2111:Dual 1863:ring 1691:) → 1262:) → 1250:pure 1232:The 1058:Prim 811:Let 776:Prim 608:Prim 559:dual 434:Prim 402:map 258:Prim 211:(or 172:The 130:for 116:dual 49:. A 1924:C*( 1916:If 1869:of 1400:on 1386:Irr 1270:↩ π 1248:is 974:min 899:)). 881:)). 553:of 516:of 223:is 176:of 146:or 64:is 26:or 3124:: 2019:– 1940:. 1383:. 1229:. 819:. 742:I( 562:A' 520:. 395:. 184:. 111:. 84:∈ 3033:) 3029:( 2930:) 2926:( 2489:e 2482:t 2475:v 2397:) 2121:) 2117:/ 2113:( 2023:) 2005:e 1998:t 1991:v 1957:) 1930:G 1926:G 1918:G 1906:A 1902:A 1887:A 1875:A 1871:A 1859:A 1837:A 1833: 1829:A 1799:G 1795:G 1788:A 1784:A 1780:A 1772:A 1738: 1726:n 1724: 1713:A 1711:( 1708:n 1702:n 1700: 1695:n 1693: 1689:A 1687:( 1684:n 1679:n 1675: 1670:n 1668: 1647:. 1644:A 1638:x 1630:n 1626:H 1602:) 1599:x 1596:( 1584:) 1581:x 1578:( 1573:i 1554:i 1549:A 1547:( 1544:n 1526:. 1523:A 1517:x 1509:n 1505:H 1495:, 1473:) 1470:x 1467:( 1443:) 1440:x 1437:( 1432:i 1410:i 1404:n 1402:H 1398:A 1394:A 1392:( 1389:n 1381:n 1376:n 1374:H 1370:n 1366: 1360:) 1358:A 1356:( 1353:n 1323:A 1314:) 1311:A 1308:( 1299:: 1273:f 1268:f 1264: 1260:A 1255:f 1246:f 1242:A 1238:A 1227:S 1219:. 1217:S 1193:) 1190:x 1187:( 1172:= 1169:) 1166:x 1163:( 1154:f 1135:S 1131: 1124: 1120:S 1105: 1073:. 1070:) 1067:A 1064:( 1046:A 1026:A 1022:A 1018:A 1014:A 997:, 994:e 991:A 986:) 983:A 980:( 968:e 957:A 944:A 940:A 928:H 926:( 924:K 920:H 918:( 916:L 909:H 907:( 905:L 897:H 895:( 893:L 889:0 886:I 879:H 877:( 875:L 871:K 869:{ 863:K 859:0 856:I 852:H 850:( 848:L 844:H 842:( 840:K 836:K 832:0 829:I 825:H 823:( 821:L 813:H 791:. 788:) 785:A 782:( 764:A 748:X 744:x 727:. 724:} 721:0 718:= 715:) 712:x 709:( 706:f 703:: 700:) 697:X 694:( 688:C 682:f 679:{ 676:= 673:) 670:x 667:( 661:I 635:. 632:) 629:) 626:X 623:( 617:C 614:( 602:X 599:: 596:I 570:X 566:A 555:A 547:A 518:A 510: 496:A 492:U 488:U 486:( 484:k 480: 470: 466:k 449:. 446:) 443:A 440:( 422:A 416:: 413:k 393:X 389:X 385:A 364:, 356:X 351:= 339:X 306:. 302:} 293:X 273:: 270:) 267:A 264:( 248:{ 244:= 236:X 217:X 201:A 197:A 189:A 178: 162:C 160:( 157:n 101: 86:A 82:x 78:x 74:H 70:K 62:H 55:A 47:A 35: 31:A

Index

C*-algebra
unitary equivalence
irreducible
*-representation
Hilbert space
dimensional
spaces
topological space
spectrum of a ring
dual
locally compact group
Fourier transform
Plancherel theorem
unimodular
separable
Tannaka–Krein duality
compact topological groups
Pontryagin duality
topology
primitive ideals
topological space
idempotent
Kuratowski closure axioms
surjective
Zariski topology
states

singletons
Gelfand dual
dual

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

↑