Knowledge (XXG)

Direct integral

Source 📝

1562: 1764: 1322: 1581: 1557:{\displaystyle {\begin{bmatrix}T_{11}&T_{12}&\cdots &T_{1n}&\cdots \\T_{21}&T_{22}&\cdots &T_{2n}&\cdots \\\vdots &\vdots &\ddots &\vdots &\cdots \\T_{n1}&T_{n2}&\cdots &T_{nn}&\cdots \\\vdots &\vdots &\cdots &\vdots &\ddots \end{bmatrix}}.} 52:. One of von Neumann's goals in this paper was to reduce the classification of (what are now called) von Neumann algebras on separable Hilbert spaces to the classification of so-called factors. Factors are analogous to full matrix algebras over a field, and von Neumann wanted to prove a continuous analogue of the 1759:{\displaystyle {\begin{bmatrix}\lambda _{1}&0&\cdots &0&\cdots \\0&\lambda _{2}&\cdots &0&\cdots \\\vdots &\vdots &\ddots &\vdots &\cdots \\0&0&\cdots &\lambda _{n}&\cdots \\\vdots &\vdots &\cdots &\vdots &\ddots \end{bmatrix}}.} 537: 3006:
The previous two theorems provide a complete classification of Abelian von Neumann algebras on separable Hilbert spaces. This classification takes into account the realization of the von Neumann algebra as an algebra of operators. If one considers the underlying von Neumann algebra independently of
907:
are allowed to vary from point to point without having a local triviality requirement (local in a measure-theoretic sense). One of the main theorems of the von Neumann theory is to show that in fact the more general definition is equivalent to the simpler one given here.
2399: 2057: 2259: 1110: 1245: 884: 995: 2874: 433: 4318: 2471: 3561: 1925: 2998: 2703: 3230: 4055: 759: 3409:
One of the main theorems of von Neumann and Murray in their original series of papers is a proof of the decomposition theorem: Any von Neumann algebra is a direct integral of factors. Precisely stated,
895:. This definition is apparently more restrictive than the one given by von Neumann and discussed in Dixmier's classic treatise on von Neumann algebras. In the more general definition, the Hilbert space 3110: 2613: 3863: 409: 1311: 2291: 1936: 3953: 3761: 3383: 3320: 340: 2068: 1006: 3648: 5028: 2927: 4208: 163: 1159: 5130: 605: 567: 4763: 789: 4508:
Theory of Operator Algebras I, II, III", encyclopedia of mathematical sciences, Springer-Verlag, 2001–2003 (the first volume was published 1979 in 1. Edition)
927: 532:{\displaystyle \mathbf {H} _{n}=\left\{{\begin{matrix}\mathbb {C} ^{n}&{\mbox{ if }}n<\omega \\\ell ^{2}&{\mbox{ if }}n=\omega \end{matrix}}\right.} 2778: 4223: 889:
Given the local nature of our definition, many definitions applicable to single Hilbert spaces apply to measurable families of Hilbert spaces as well.
4768: 4541: 5115: 3883:
are decomposable operators. This can be used to prove the basic result of von Neumann: any von Neumann algebra admits a decomposition into factors.
1843: 63:
of matrices; in this case the results are easy to prove directly. The infinite-dimensional case is complicated by measure-theoretic technicalities.
5008: 2410: 4861: 4659: 4856: 1852: 911:
Note that the direct integral of a measurable family of Hilbert spaces depends only on the measure class of the measure μ; more precisely:
2946: 1575:, having zero for all non-diagonal entries. Decomposable operators can be characterized as those which commute with diagonal matrices: 2639: 5013: 4513: 4479: 4466: 4440: 3156: 3995: 704: 3441: 4831: 3435:
is a measurable family of von Neumann algebras and μ is standard, then the family of operator commutants is also measurable and
764:
consists of equivalence classes (with respect to almost everywhere equality) of measurable square integrable cross-sections of {
4800: 3063: 4790: 4785: 4778: 4714: 4598: 2557: 2394:{\displaystyle \phi :L_{\mu }^{\infty }(X)\rightarrow \operatorname {L} {\bigg (}\int _{X}^{\oplus }H_{x}\ d\mu (x){\bigg )}} 3814: 2052:{\displaystyle \int _{X}^{\oplus }\ T_{x}d\mu (x)\in \operatorname {L} {\bigg (}\int _{X}^{\oplus }H_{x}\ d\mu (x){\bigg )}} 355: 1265: 5191: 5023: 4534: 3007:
its realization (as a von Neumann algebra), then its structure is determined by very simple measure-theoretic invariants.
53: 5181: 4649: 4161:, μ) (which, as stated, is unique in a measure theoretic sense), there is a measurable family of factor representations 3895: 5160: 4634: 2254:{\displaystyle {\bigg }{\bigg (}\int _{X}^{\oplus }\ s_{x}d\mu (x){\bigg )}=\int _{X}^{\oplus }\ T_{x}(s_{x})d\mu (x).} 1105:{\displaystyle \int _{X}^{\oplus }H_{x}\,\mathrm {d} \mu (x)\rightarrow \int _{X}^{\oplus }H_{x}\,\mathrm {d} \nu (x).} 5080: 3715: 3331: 3268: 2522: 5135: 5033: 4913: 293: 207: 171:: The terminology adopted by the literature on the subject is followed here, according to which a measurable space 4629: 5140: 5003: 4836: 4821: 4593: 2888: 4722: 4732: 4603: 4527: 4105:
has a unit, non-degeneracy is equivalent to unit-preserving. By the general correspondence that exists between
3690:
is a von Neumann algebra whose center contains a sequence of minimal pairwise orthogonal non-zero projections {
3605: 5186: 5095: 5070: 4888: 4877: 4588: 574: 102: 71: 4946: 4936: 4931: 4167: 4639: 4109: 75: 3872:
as a direct sum of factors. This is a special case of the central decomposition theorem of von Neumann.
287:, which is locally equivalent to a trivial family in the following sense: There is a countable partition 4691: 4364: 4113: 3003:
The isomorphism φ is a measure class isomorphism, in that φ and its inverse preserve sets of measure 0.
118: 79: 2736:
This version of the spectral theorem does not explicitly state how the underlying standard Borel space
1240:{\displaystyle \int _{X}^{\oplus }H_{x}\,\mathrm {d} \mu (x)\cong \bigoplus _{k\in \mathbb {N} }H_{k}} 5105: 5084: 4998: 4883: 4846: 4404: 2496:
Decomposable operators are precisely those that are in the operator commutant of the abelian algebra
243: 4908: 4644: 4106: 3035: 1808: 206:; all Polish spaces of a given cardinality are isomorphic to each other (as Borel spaces). Given a 41: 21: 5038: 4967: 4898: 4742: 4704: 4504: 4424: 4123:), the theory for C*-algebras immediately provides a decomposition theory for representations of 4097:, the above results can be applied to measurable families of non-degenerate *-representations of 59:
Results on direct integrals can be viewed as generalizations of results about finite-dimensional
580: 3879:) as an algebra of scalar diagonal operators. In any such representation, all the operators in 545: 5145: 5120: 4805: 4727: 4509: 4475: 4462: 4436: 2880: 695: 192: 5150: 4851: 4699: 4654: 4578: 3584: 3262:
is a measurable family of von Neumann algebras, the direct integral of von Neumann algebras
1129: 95: 45: 879:{\displaystyle \langle s|t\rangle =\int _{X}\langle s(x)|t(x)\rangle \,\mathrm {d} \mu (x)} 5125: 5110: 5018: 4981: 4977: 4941: 4903: 4841: 4826: 4737: 4696: 4683: 4608: 4550: 4432: 4157:. Then corresponding to any central decomposition of W*(π) over a standard measure space ( 4124: 990:{\displaystyle s\mapsto \left({\frac {\mathrm {d} \mu }{\mathrm {d} \nu }}\right)^{1/2}s} 677:. A cross-section is measurable if and only if its restriction to each partition element 4403:. This decomposition is essentially unique. This result is fundamental in the theory of 5075: 5054: 4972: 4962: 4773: 4680: 4613: 4573: 4494: 3116: 2869:{\displaystyle \int _{X}^{\oplus }H_{x}d\mu (x),\quad \int _{Y}^{\oplus }K_{y}d\nu (y)} 2515:
The spectral theorem has many variants. A particularly powerful version is as follows:
1572: 570: 215: 199: 1255:
For the example of a discrete measure on a countable set, any bounded linear operator
5175: 1125: 67: 37: 4313:{\displaystyle \pi (a)=\int _{X}^{\oplus }\pi _{x}(a)d\mu (x),\quad \forall a\in A.} 4893: 4747: 4688: 4484: 1769:
The above example motivates the general definition: A family of bounded operators {
203: 4501:
The Annals of Mathematics 2nd Ser., Vol. 50, No. 2 (Apr., 1949), pp. 401–485.
1153:} of separable Hilbert spaces can be considered as a measurable family. Moreover, 180: 4519: 5090: 4675: 247: 17: 3875:
In general, the structure theorem of Abelian von Neumann algebras represents Z(
4583: 4454: 4137:
be a separable C*-algebra and π a non-degenerate involutive representation of
4094: 188: 60: 33: 4568: 4554: 2271:
Examples of decomposable operators are those defined by scalar-valued (i.e.
5155: 5100: 2466:{\displaystyle \lambda \mapsto \int _{X}^{\oplus }\ \lambda _{x}d\mu (x)} 219: 4498: 4381:, consisting of quasi-equivalence classes of factor representations of 2740:
is obtained. There is a uniqueness result for the above decomposition.
4370:
One can show that the direct integral can be indexed on the so-called
2729:). Note that this asserts more than just the algebraic equivalence of 1920:{\displaystyle \operatorname {ess-sup} _{x\in X}\|T_{x}\|<\infty } 191:, regardless of whether or not the underlying σ-algebra comes from a 4145:. Let W*(π) be the von Neumann algebra generated by the operators π( 94:
spaces associated to a (σ-finite) countably additive measure μ on a
698:. Given a measurable family of Hilbert spaces, the direct integral 2993:{\displaystyle K_{\phi (x)}=H_{x}\quad {\mbox{almost everywhere}}} 4119:
and non-degenerate *-representations of the groups C*-algebra C*(
260:
be a Borel space equipped with a countably additive measure μ. A
3675:
is a von Neumann algebra, if the center is 1-dimensional we say
3142:
as a von Neumann algebra in the following sense: For almost all
4523: 2698:{\displaystyle U:H\rightarrow \int _{X}^{\oplus }H_{x}d\mu (x)} 2540:
such that it is unitarily equivalent as an operator algebra to
3225:{\displaystyle \operatorname {W^{*}} (\{S_{x}:S\in D\})=A_{x}} 4389:
and a measurable family of factor representations indexed on
4050:{\displaystyle \mathbf {A} =\int _{X}^{\oplus }A_{x}d\mu (x)} 3974:) is represented by the algebra of scalar diagonal operators 754:{\displaystyle \int _{X}^{\oplus }H_{x}\,\mathrm {d} \mu (x)} 3556:{\displaystyle {\bigg }'=\int _{X}^{\oplus }A'_{x}d\mu (x).} 1567:
For this example, of a discrete measure on a countable set,
917:. Suppose μ, ν are σ-finite countably additive measures on 526: 686:
is measurable. We will identify measurable cross-sections
3123:
of measurable operator families that pointwise generate {
3105:{\displaystyle A_{x}\subseteq \operatorname {L} (H_{x})} 3239:) denotes the von Neumann algebra generated by the set 2633:) as an operator algebra means that there is a unitary 2608:{\displaystyle \int _{X}^{\oplus }H_{x}d\mu (x).\quad } 2476:
is an involutive algebraic isomorphism onto its image.
921:
that have the same sets of measure 0. Then the mapping
36:. The theory is most developed for direct integrals of 3858:{\displaystyle A=\bigoplus _{i\in \mathbb {N} }AE_{i}} 3034:
be a measurable family of Hilbert spaces. A family of
2984: 1590: 1331: 507: 475: 457: 404:{\displaystyle H_{x}=\mathbf {H} _{n}\quad x\in X_{n}} 4226: 4170: 3998: 3898: 3817: 3718: 3608: 3444: 3334: 3271: 3159: 3066: 2949: 2891: 2781: 2642: 2560: 2413: 2294: 2071: 1939: 1855: 1584: 1325: 1306:{\displaystyle H=\bigoplus _{k\in \mathbb {N} }H_{k}} 1268: 1162: 1009: 930: 792: 707: 583: 548: 436: 358: 296: 121: 202:
it is isomorphic to the underlying Borel space of a
5063: 5047: 4991: 4955: 4924: 4870: 4814: 4756: 4713: 4668: 4622: 4561: 5131:Spectral theory of ordinary differential equations 4312: 4202: 4049: 3948:{\displaystyle H=\int _{X}^{\oplus }H_{x}d\mu (x)} 3947: 3857: 3755: 3642: 3555: 3377: 3314: 3224: 3104: 2992: 2921: 2868: 2697: 2607: 2465: 2393: 2253: 2051: 1919: 1758: 1556: 1305: 1239: 1104: 989: 878: 783:. This is a Hilbert space under the inner product 753: 599: 561: 531: 403: 334: 157: 90:The simplest example of a direct integral are the 5029:Schröder–Bernstein theorems for operator algebras 3495: 3447: 2386: 2336: 2181: 2131: 2124: 2074: 2044: 1994: 1821:is strongly measurable. This makes sense because 3756:{\displaystyle 1=\sum _{i\in \mathbb {N} }E_{i}} 3378:{\displaystyle \int _{X}^{\oplus }T_{x}d\mu (x)} 3315:{\displaystyle \int _{X}^{\oplus }A_{x}d\mu (x)} 2879:and μ, ν are standard measures, then there is a 2551:) acting on a direct integral of Hilbert spaces 335:{\displaystyle \{X_{n}\}_{1\leq n\leq \omega }} 4535: 2511:Decomposition of Abelian von Neumann algebras 195:(in most examples it does). A Borel space is 101:. Somewhat more generally one can consider a 8: 4185: 4171: 3203: 3178: 1908: 1895: 855: 823: 807: 793: 311: 297: 4489:The Theory of Unitary Group Representations 2922:{\displaystyle \varphi :X-E\rightarrow Y-F} 230:measure if and only if there is a null set 4542: 4528: 4520: 4385:. Thus, there is a standard measure μ on 218:is one that differs from a Borel set by a 4261: 4251: 4246: 4225: 4188: 4178: 4169: 4026: 4016: 4011: 3999: 3997: 3924: 3914: 3909: 3897: 3849: 3836: 3835: 3828: 3816: 3747: 3737: 3736: 3729: 3717: 3609: 3607: 3526: 3516: 3511: 3494: 3493: 3471: 3461: 3456: 3446: 3445: 3443: 3354: 3344: 3339: 3333: 3291: 3281: 3276: 3270: 3216: 3185: 3165: 3160: 3158: 3093: 3071: 3065: 2983: 2976: 2954: 2948: 2890: 2845: 2835: 2830: 2801: 2791: 2786: 2780: 2674: 2664: 2659: 2641: 2580: 2570: 2565: 2559: 2442: 2429: 2424: 2412: 2385: 2384: 2360: 2350: 2345: 2335: 2334: 2310: 2305: 2293: 2224: 2211: 2198: 2193: 2180: 2179: 2158: 2145: 2140: 2130: 2129: 2123: 2122: 2101: 2088: 2083: 2073: 2072: 2070: 2043: 2042: 2018: 2008: 2003: 1993: 1992: 1962: 1949: 1944: 1938: 1902: 1880: 1857: 1854: 1842:Measurable families of operators with an 1707: 1636: 1597: 1585: 1583: 1502: 1482: 1467: 1418: 1401: 1389: 1367: 1350: 1338: 1326: 1324: 1297: 1287: 1286: 1279: 1267: 1231: 1221: 1220: 1213: 1189: 1188: 1182: 1172: 1167: 1161: 1082: 1081: 1075: 1065: 1060: 1036: 1035: 1029: 1019: 1014: 1008: 974: 970: 955: 945: 942: 929: 859: 858: 838: 817: 799: 791: 734: 733: 727: 717: 712: 706: 588: 582: 553: 547: 506: 498: 474: 466: 462: 461: 456: 443: 438: 435: 395: 378: 373: 363: 357: 314: 304: 295: 131: 126: 120: 4491:, The University of Chicago Press, 1976. 3808:is a factor. Thus, in this special case 3643:{\displaystyle \mathbf {Z} (A)=A\cap A'} 3591:. The center is the set of operators in 3011:Direct integrals of von Neumann algebras 2733:with the algebra of diagonal operators. 2490:) to be identified with the image of φ. 66:Direct integral theory was also used by 44:. The concept was introduced in 1949 by 4499:On Rings of Operators. Reduction Theory 4416: 4359:, where representations are said to be 2772:) acting on the direct integral spaces 2718:* is the algebra of diagonal operators 2062:acting in a pointwise fashion, that is 1812:if and only if its restriction to each 4085:Measurable families of representations 3958:is a direct integral decomposition of 3778:is a von Neumann algebra on the range 3325:consists of all operators of the form 1571:are defined as the operators that are 179:and the elements of the distinguished 32:is a generalization of the concept of 4862:Spectral theory of normal C*-algebras 4660:Spectral theory of normal C*-algebras 4203:{\displaystyle \{\pi _{x}\}_{x\in X}} 3661:) is an Abelian von Neumann algebra. 2746:. If the Abelian von Neumann algebra 7: 4857:Spectral theory of compact operators 427:-dimensional Hilbert space, that is 4077:is a von Neumann algebra that is a 3671:) is 1-dimensional. In general, if 2275:-valued) measurable functions λ on 262:measurable family of Hilbert spaces 246:. All measures considered here are 108:and the space of square-integrable 48:in one of the papers in the series 5009:Cohen–Hewitt factorization theorem 4446:, Chapter IV, Theorem 7.10, p. 259 4295: 3162: 3080: 2532:, there is a standard Borel space 2328: 2311: 1986: 1914: 1876: 1873: 1870: 1864: 1861: 1858: 1190: 1083: 1037: 956: 946: 860: 735: 158:{\displaystyle L_{\mu }^{2}(X,H).} 86:Direct integrals of Hilbert spaces 14: 5014:Extensions of symmetric operators 1120:The simplest example occurs when 4832:Positive operator-valued measure 4331:with μ measure zero, such that π 4000: 3989:is a standard Borel space. Then 3610: 3595:that commute with all operators 2750:is unitarily equivalent to both 1930:define bounded linear operators 439: 374: 80:locally compact separable groups 5116:Rayleigh–Faber–Krahn inequality 4294: 2982: 2825: 2604: 1316:is given by an infinite matrix 384: 56:classifying semi-simple rings. 4288: 4282: 4273: 4267: 4236: 4230: 4044: 4038: 3942: 3936: 3620: 3614: 3575:is a von Neumann algebra. Let 3547: 3541: 3489: 3483: 3372: 3366: 3309: 3303: 3206: 3175: 3099: 3086: 2964: 2958: 2907: 2863: 2857: 2819: 2813: 2692: 2686: 2652: 2598: 2592: 2460: 2454: 2417: 2381: 2375: 2325: 2322: 2316: 2264:Such operators are said to be 2245: 2239: 2230: 2217: 2176: 2170: 2119: 2113: 2039: 2033: 1980: 1974: 1203: 1197: 1096: 1090: 1053: 1050: 1044: 934: 873: 867: 852: 846: 839: 835: 829: 800: 748: 742: 149: 137: 1: 5024:Limiting absorption principle 4429:Theory of Operator Algebras I 4141:on a separable Hilbert space 2528:on a separable Hilbert space 1140:and μ is counting measure on 4650:Singular value decomposition 4363:if and only if there are no 4323:Moreover, there is a subset 3966:is a von Neumann algebra on 5081:Hearing the shape of a drum 4764:Decomposition of a spectrum 2622:is unitarily equivalent to 2523:Abelian von Neumann algebra 5208: 4669:Special Elements/Operators 600:{\displaystyle \ell ^{2}.} 208:countably additive measure 74:and his general theory of 5141:Superstrong approximation 5004:Banach algebra cohomology 4837:Projection-valued measure 4822:Borel functional calculus 4594:Projection-valued measure 3119:there is a countable set 571:square summable sequences 562:{\displaystyle \ell ^{2}} 345:by measurable subsets of 234:such that its complement 4733:Spectrum of a C*-algebra 4604:Spectrum of a C*-algebra 4399:belongs to the class of 4127:locally compact groups. 2940:are null sets such that 1844:essentially bounded norm 575:separable Hilbert spaces 72:systems of imprimitivity 54:Artin–Wedderburn theorem 40:and direct integrals of 5161:Wiener–Khinchin theorem 5096:Kuznetsov trace formula 5071:Almost Mathieu operator 4889:Banach function algebra 4878:Amenable Banach algebra 4635:Gelfand–Naimark theorem 4589:Noncommutative topology 4110:unitary representations 103:separable Hilbert space 76:induced representations 5136:Sturm–Liouville theory 5034:Sherman–Takeda theorem 4914:Tomita–Takesaki theory 4689:Hermitian/Self-adjoint 4640:Gelfand representation 4365:intertwining operators 4343:are disjoint whenever 4314: 4204: 4051: 3949: 3859: 3757: 3644: 3557: 3379: 3316: 3226: 3106: 2994: 2923: 2870: 2699: 2609: 2467: 2395: 2255: 2053: 1921: 1760: 1569:decomposable operators 1558: 1307: 1251:Decomposable operators 1241: 1106: 1000:is a unitary operator 991: 880: 755: 601: 563: 533: 405: 336: 159: 4630:Gelfand–Mazur theorem 4405:group representations 4315: 4205: 4114:locally compact group 4060:where for almost all 4052: 3950: 3860: 3758: 3645: 3567:Central decomposition 3558: 3380: 3317: 3227: 3107: 2995: 2924: 2871: 2700: 2610: 2468: 2396: 2256: 2054: 1922: 1761: 1559: 1308: 1242: 1144:, then any sequence { 1107: 992: 881: 756: 602: 564: 534: 406: 337: 160: 50:On Rings of Operators 5192:Von Neumann algebras 5106:Proto-value function 5085:Dirichlet eigenvalue 4999:Abstract index group 4884:Approximate identity 4847:Rigged Hilbert space 4723:Krein–Rutman theorem 4569:Involution/*-algebra 4459:Von Neumann algebras 4224: 4168: 3996: 3896: 3815: 3796:. It is easy to see 3716: 3606: 3442: 3332: 3269: 3157: 3064: 3036:von Neumann algebras 2947: 2889: 2779: 2640: 2558: 2411: 2292: 2069: 1937: 1853: 1582: 1323: 1266: 1160: 1007: 928: 790: 705: 581: 546: 434: 356: 294: 244:standard Borel space 222:. The measure μ on 175:is referred to as a 119: 42:von Neumann algebras 5182:Functional analysis 4909:Von Neumann algebra 4645:Polar decomposition 4425:Takesaki, Masamichi 4256: 4107:strongly continuous 4101:. In the case that 4021: 3919: 3534: 3521: 3466: 3349: 3286: 2840: 2796: 2669: 2575: 2536:and a measure μ on 2434: 2355: 2315: 2203: 2150: 2093: 2013: 1954: 1809:strongly measurable 1177: 1070: 1024: 722: 169:Terminological note 136: 70:in his analysis of 22:functional analysis 5039:Unbounded operator 4968:Essential spectrum 4947:Schur–Horn theorem 4937:Bauer–Fike theorem 4932:Alon–Boppana bound 4925:Finite-Dimensional 4899:Nuclear C*-algebra 4743:Spectral asymmetry 4505:Masamichi Takesaki 4310: 4242: 4200: 4047: 4007: 3945: 3905: 3855: 3841: 3753: 3742: 3667:. The center of L( 3640: 3553: 3522: 3507: 3452: 3375: 3335: 3312: 3272: 3222: 3102: 2990: 2988: 2919: 2866: 2826: 2782: 2695: 2655: 2605: 2561: 2463: 2420: 2391: 2341: 2301: 2251: 2189: 2136: 2079: 2049: 1999: 1940: 1917: 1756: 1747: 1554: 1545: 1303: 1292: 1237: 1226: 1163: 1102: 1056: 1010: 987: 876: 751: 708: 597: 577:are isomorphic to 559: 529: 524: 511: 479: 401: 332: 268:, μ) is a family { 155: 122: 112:-valued functions 5169: 5168: 5146:Transfer operator 5121:Spectral geometry 4806:Spectral abscissa 4786:Approximate point 4728:Normal eigenvalue 3824: 3725: 3168: 2987: 2986:almost everywhere 2881:Borel isomorphism 2437: 2368: 2206: 2153: 2096: 2026: 1957: 1869: 1275: 1209: 964: 696:almost everywhere 510: 478: 423:is the canonical 193:topological space 5199: 5151:Transform theory 4871:Special algebras 4852:Spectral theorem 4815:Spectral Theorem 4655:Spectral theorem 4544: 4537: 4530: 4521: 4447: 4445: 4421: 4319: 4317: 4316: 4311: 4266: 4265: 4255: 4250: 4209: 4207: 4206: 4201: 4199: 4198: 4183: 4182: 4056: 4054: 4053: 4048: 4031: 4030: 4020: 4015: 4003: 3954: 3952: 3951: 3946: 3929: 3928: 3918: 3913: 3864: 3862: 3861: 3856: 3854: 3853: 3840: 3839: 3762: 3760: 3759: 3754: 3752: 3751: 3741: 3740: 3649: 3647: 3646: 3641: 3639: 3613: 3562: 3560: 3559: 3554: 3530: 3520: 3515: 3503: 3499: 3498: 3476: 3475: 3465: 3460: 3451: 3450: 3384: 3382: 3381: 3376: 3359: 3358: 3348: 3343: 3321: 3319: 3318: 3313: 3296: 3295: 3285: 3280: 3231: 3229: 3228: 3223: 3221: 3220: 3190: 3189: 3171: 3170: 3169: 3166: 3111: 3109: 3108: 3103: 3098: 3097: 3076: 3075: 2999: 2997: 2996: 2991: 2989: 2985: 2981: 2980: 2968: 2967: 2928: 2926: 2925: 2920: 2875: 2873: 2872: 2867: 2850: 2849: 2839: 2834: 2806: 2805: 2795: 2790: 2704: 2702: 2701: 2696: 2679: 2678: 2668: 2663: 2614: 2612: 2611: 2606: 2585: 2584: 2574: 2569: 2472: 2470: 2469: 2464: 2447: 2446: 2435: 2433: 2428: 2400: 2398: 2397: 2392: 2390: 2389: 2366: 2365: 2364: 2354: 2349: 2340: 2339: 2314: 2309: 2260: 2258: 2257: 2252: 2229: 2228: 2216: 2215: 2204: 2202: 2197: 2185: 2184: 2163: 2162: 2151: 2149: 2144: 2135: 2134: 2128: 2127: 2106: 2105: 2094: 2092: 2087: 2078: 2077: 2058: 2056: 2055: 2050: 2048: 2047: 2024: 2023: 2022: 2012: 2007: 1998: 1997: 1967: 1966: 1955: 1953: 1948: 1926: 1924: 1923: 1918: 1907: 1906: 1891: 1890: 1879: 1867: 1806:) is said to be 1765: 1763: 1762: 1757: 1752: 1751: 1712: 1711: 1641: 1640: 1602: 1601: 1563: 1561: 1560: 1555: 1550: 1549: 1510: 1509: 1490: 1489: 1475: 1474: 1426: 1425: 1406: 1405: 1394: 1393: 1375: 1374: 1355: 1354: 1343: 1342: 1312: 1310: 1309: 1304: 1302: 1301: 1291: 1290: 1246: 1244: 1243: 1238: 1236: 1235: 1225: 1224: 1193: 1187: 1186: 1176: 1171: 1130:discrete measure 1111: 1109: 1108: 1103: 1086: 1080: 1079: 1069: 1064: 1040: 1034: 1033: 1023: 1018: 996: 994: 993: 988: 983: 982: 978: 969: 965: 963: 959: 953: 949: 943: 885: 883: 882: 877: 863: 842: 822: 821: 803: 760: 758: 757: 752: 738: 732: 731: 721: 716: 606: 604: 603: 598: 593: 592: 569:is the space of 568: 566: 565: 560: 558: 557: 538: 536: 535: 530: 528: 525: 512: 508: 503: 502: 480: 476: 471: 470: 465: 448: 447: 442: 410: 408: 407: 402: 400: 399: 383: 382: 377: 368: 367: 341: 339: 338: 333: 331: 330: 309: 308: 164: 162: 161: 156: 135: 130: 96:measurable space 46:John von Neumann 30:Hilbert integral 5207: 5206: 5202: 5201: 5200: 5198: 5197: 5196: 5172: 5171: 5170: 5165: 5126:Spectral method 5111:Ramanujan graph 5059: 5043: 5019:Fredholm theory 4987: 4982:Shilov boundary 4978:Structure space 4956:Generalizations 4951: 4942:Numerical range 4920: 4904:Uniform algebra 4866: 4842:Riesz projector 4827:Min-max theorem 4810: 4796:Direct integral 4752: 4738:Spectral radius 4709: 4664: 4618: 4609:Spectral radius 4557: 4551:Spectral theory 4548: 4451: 4450: 4443: 4433:Springer-Verlag 4423: 4422: 4418: 4413: 4398: 4342: 4336: 4257: 4222: 4221: 4184: 4174: 4166: 4165: 4093:is a separable 4087: 4076: 4022: 3994: 3993: 3980: 3920: 3894: 3893: 3845: 3813: 3812: 3807: 3795: 3786: 3777: 3743: 3714: 3713: 3708: 3698: 3632: 3604: 3603: 3569: 3492: 3467: 3440: 3439: 3434: 3424: 3405: 3396: 3350: 3330: 3329: 3287: 3267: 3266: 3261: 3251: 3212: 3181: 3161: 3155: 3154: 3141: 3131: 3089: 3067: 3062: 3061: 3056: 3046: 3033: 3023: 3013: 2972: 2950: 2945: 2944: 2887: 2886: 2841: 2797: 2777: 2776: 2767: 2756: 2724: 2670: 2638: 2637: 2628: 2576: 2556: 2555: 2546: 2513: 2502: 2485: 2438: 2409: 2408: 2356: 2290: 2289: 2220: 2207: 2154: 2097: 2067: 2066: 2014: 1958: 1935: 1934: 1898: 1856: 1851: 1850: 1838: 1830:is constant on 1829: 1820: 1805: 1796: 1787: 1777: 1746: 1745: 1740: 1735: 1730: 1725: 1719: 1718: 1713: 1703: 1701: 1696: 1691: 1685: 1684: 1679: 1674: 1669: 1664: 1658: 1657: 1652: 1647: 1642: 1632: 1630: 1624: 1623: 1618: 1613: 1608: 1603: 1593: 1586: 1580: 1579: 1544: 1543: 1538: 1533: 1528: 1523: 1517: 1516: 1511: 1498: 1496: 1491: 1478: 1476: 1463: 1460: 1459: 1454: 1449: 1444: 1439: 1433: 1432: 1427: 1414: 1412: 1407: 1397: 1395: 1385: 1382: 1381: 1376: 1363: 1361: 1356: 1346: 1344: 1334: 1327: 1321: 1320: 1293: 1264: 1263: 1253: 1227: 1178: 1158: 1157: 1152: 1118: 1071: 1025: 1005: 1004: 954: 944: 938: 937: 926: 925: 906: 813: 788: 787: 782: 772: 723: 703: 702: 694:that are equal 685: 668: 659: 650: 640: 631: 621: 584: 579: 578: 549: 544: 543: 523: 522: 504: 494: 491: 490: 472: 460: 452: 437: 432: 431: 422: 391: 372: 359: 354: 353: 310: 300: 292: 291: 286: 276: 117: 116: 88: 26:direct integral 12: 11: 5: 5205: 5203: 5195: 5194: 5189: 5187:Measure theory 5184: 5174: 5173: 5167: 5166: 5164: 5163: 5158: 5153: 5148: 5143: 5138: 5133: 5128: 5123: 5118: 5113: 5108: 5103: 5098: 5093: 5088: 5078: 5076:Corona theorem 5073: 5067: 5065: 5061: 5060: 5058: 5057: 5055:Wiener algebra 5051: 5049: 5045: 5044: 5042: 5041: 5036: 5031: 5026: 5021: 5016: 5011: 5006: 5001: 4995: 4993: 4989: 4988: 4986: 4985: 4975: 4973:Pseudospectrum 4970: 4965: 4963:Dirac spectrum 4959: 4957: 4953: 4952: 4950: 4949: 4944: 4939: 4934: 4928: 4926: 4922: 4921: 4919: 4918: 4917: 4916: 4906: 4901: 4896: 4891: 4886: 4880: 4874: 4872: 4868: 4867: 4865: 4864: 4859: 4854: 4849: 4844: 4839: 4834: 4829: 4824: 4818: 4816: 4812: 4811: 4809: 4808: 4803: 4798: 4793: 4788: 4783: 4782: 4781: 4776: 4771: 4760: 4758: 4754: 4753: 4751: 4750: 4745: 4740: 4735: 4730: 4725: 4719: 4717: 4711: 4710: 4708: 4707: 4702: 4694: 4686: 4678: 4672: 4670: 4666: 4665: 4663: 4662: 4657: 4652: 4647: 4642: 4637: 4632: 4626: 4624: 4620: 4619: 4617: 4616: 4614:Operator space 4611: 4606: 4601: 4596: 4591: 4586: 4581: 4576: 4574:Banach algebra 4571: 4565: 4563: 4562:Basic concepts 4559: 4558: 4549: 4547: 4546: 4539: 4532: 4524: 4518: 4517: 4502: 4495:J. von Neumann 4492: 4482: 4469: 4449: 4448: 4441: 4415: 4414: 4412: 4409: 4394: 4372:quasi-spectrum 4367:between them. 4338: 4332: 4321: 4320: 4309: 4306: 4303: 4300: 4297: 4293: 4290: 4287: 4284: 4281: 4278: 4275: 4272: 4269: 4264: 4260: 4254: 4249: 4245: 4241: 4238: 4235: 4232: 4229: 4211: 4210: 4197: 4194: 4191: 4187: 4181: 4177: 4173: 4086: 4083: 4072: 4058: 4057: 4046: 4043: 4040: 4037: 4034: 4029: 4025: 4019: 4014: 4010: 4006: 4002: 3978: 3956: 3955: 3944: 3941: 3938: 3935: 3932: 3927: 3923: 3917: 3912: 3908: 3904: 3901: 3866: 3865: 3852: 3848: 3844: 3838: 3834: 3831: 3827: 3823: 3820: 3803: 3791: 3782: 3773: 3764: 3763: 3750: 3746: 3739: 3735: 3732: 3728: 3724: 3721: 3700: 3694: 3651: 3650: 3638: 3635: 3631: 3628: 3625: 3622: 3619: 3616: 3612: 3568: 3565: 3564: 3563: 3552: 3549: 3546: 3543: 3540: 3537: 3533: 3529: 3525: 3519: 3514: 3510: 3506: 3502: 3497: 3491: 3488: 3485: 3482: 3479: 3474: 3470: 3464: 3459: 3455: 3449: 3426: 3420: 3401: 3392: 3386: 3385: 3374: 3371: 3368: 3365: 3362: 3357: 3353: 3347: 3342: 3338: 3323: 3322: 3311: 3308: 3305: 3302: 3299: 3294: 3290: 3284: 3279: 3275: 3253: 3247: 3233: 3232: 3219: 3215: 3211: 3208: 3205: 3202: 3199: 3196: 3193: 3188: 3184: 3180: 3177: 3174: 3164: 3133: 3127: 3117:if and only if 3115:is measurable 3113: 3112: 3101: 3096: 3092: 3088: 3085: 3082: 3079: 3074: 3070: 3048: 3042: 3025: 3019: 3012: 3009: 3001: 3000: 2979: 2975: 2971: 2966: 2963: 2960: 2957: 2953: 2930: 2929: 2918: 2915: 2912: 2909: 2906: 2903: 2900: 2897: 2894: 2877: 2876: 2865: 2862: 2859: 2856: 2853: 2848: 2844: 2838: 2833: 2829: 2824: 2821: 2818: 2815: 2812: 2809: 2804: 2800: 2794: 2789: 2785: 2765: 2754: 2722: 2706: 2705: 2694: 2691: 2688: 2685: 2682: 2677: 2673: 2667: 2662: 2658: 2654: 2651: 2648: 2645: 2626: 2616: 2615: 2603: 2600: 2597: 2594: 2591: 2588: 2583: 2579: 2573: 2568: 2564: 2544: 2512: 2509: 2500: 2483: 2474: 2473: 2462: 2459: 2456: 2453: 2450: 2445: 2441: 2432: 2427: 2423: 2419: 2416: 2402: 2401: 2388: 2383: 2380: 2377: 2374: 2371: 2363: 2359: 2353: 2348: 2344: 2338: 2333: 2330: 2327: 2324: 2321: 2318: 2313: 2308: 2304: 2300: 2297: 2285:. The mapping 2262: 2261: 2250: 2247: 2244: 2241: 2238: 2235: 2232: 2227: 2223: 2219: 2214: 2210: 2201: 2196: 2192: 2188: 2183: 2178: 2175: 2172: 2169: 2166: 2161: 2157: 2148: 2143: 2139: 2133: 2126: 2121: 2118: 2115: 2112: 2109: 2104: 2100: 2091: 2086: 2082: 2076: 2060: 2059: 2046: 2041: 2038: 2035: 2032: 2029: 2021: 2017: 2011: 2006: 2002: 1996: 1991: 1988: 1985: 1982: 1979: 1976: 1973: 1970: 1965: 1961: 1952: 1947: 1943: 1928: 1927: 1916: 1913: 1910: 1905: 1901: 1897: 1894: 1889: 1886: 1883: 1878: 1875: 1872: 1866: 1863: 1860: 1834: 1825: 1816: 1801: 1792: 1779: 1773: 1767: 1766: 1755: 1750: 1744: 1741: 1739: 1736: 1734: 1731: 1729: 1726: 1724: 1721: 1720: 1717: 1714: 1710: 1706: 1702: 1700: 1697: 1695: 1692: 1690: 1687: 1686: 1683: 1680: 1678: 1675: 1673: 1670: 1668: 1665: 1663: 1660: 1659: 1656: 1653: 1651: 1648: 1646: 1643: 1639: 1635: 1631: 1629: 1626: 1625: 1622: 1619: 1617: 1614: 1612: 1609: 1607: 1604: 1600: 1596: 1592: 1591: 1589: 1573:block diagonal 1565: 1564: 1553: 1548: 1542: 1539: 1537: 1534: 1532: 1529: 1527: 1524: 1522: 1519: 1518: 1515: 1512: 1508: 1505: 1501: 1497: 1495: 1492: 1488: 1485: 1481: 1477: 1473: 1470: 1466: 1462: 1461: 1458: 1455: 1453: 1450: 1448: 1445: 1443: 1440: 1438: 1435: 1434: 1431: 1428: 1424: 1421: 1417: 1413: 1411: 1408: 1404: 1400: 1396: 1392: 1388: 1384: 1383: 1380: 1377: 1373: 1370: 1366: 1362: 1360: 1357: 1353: 1349: 1345: 1341: 1337: 1333: 1332: 1330: 1314: 1313: 1300: 1296: 1289: 1285: 1282: 1278: 1274: 1271: 1252: 1249: 1248: 1247: 1234: 1230: 1223: 1219: 1216: 1212: 1208: 1205: 1202: 1199: 1196: 1192: 1185: 1181: 1175: 1170: 1166: 1148: 1117: 1114: 1113: 1112: 1101: 1098: 1095: 1092: 1089: 1085: 1078: 1074: 1068: 1063: 1059: 1055: 1052: 1049: 1046: 1043: 1039: 1032: 1028: 1022: 1017: 1013: 998: 997: 986: 981: 977: 973: 968: 962: 958: 952: 948: 941: 936: 933: 902: 887: 886: 875: 872: 869: 866: 862: 857: 854: 851: 848: 845: 841: 837: 834: 831: 828: 825: 820: 816: 812: 809: 806: 802: 798: 795: 774: 768: 762: 761: 750: 747: 744: 741: 737: 730: 726: 720: 715: 711: 681: 664: 655: 642: 636: 623: 617: 596: 591: 587: 556: 552: 542:In the above, 540: 539: 527: 521: 518: 515: 509: if  505: 501: 497: 493: 492: 489: 486: 483: 477: if  473: 469: 464: 459: 458: 455: 451: 446: 441: 418: 412: 411: 398: 394: 390: 387: 381: 376: 371: 366: 362: 343: 342: 329: 326: 323: 320: 317: 313: 307: 303: 299: 278: 272: 216:measurable set 200:if and only if 166: 165: 154: 151: 148: 145: 142: 139: 134: 129: 125: 87: 84: 38:Hilbert spaces 13: 10: 9: 6: 4: 3: 2: 5204: 5193: 5190: 5188: 5185: 5183: 5180: 5179: 5177: 5162: 5159: 5157: 5154: 5152: 5149: 5147: 5144: 5142: 5139: 5137: 5134: 5132: 5129: 5127: 5124: 5122: 5119: 5117: 5114: 5112: 5109: 5107: 5104: 5102: 5099: 5097: 5094: 5092: 5089: 5086: 5082: 5079: 5077: 5074: 5072: 5069: 5068: 5066: 5062: 5056: 5053: 5052: 5050: 5046: 5040: 5037: 5035: 5032: 5030: 5027: 5025: 5022: 5020: 5017: 5015: 5012: 5010: 5007: 5005: 5002: 5000: 4997: 4996: 4994: 4992:Miscellaneous 4990: 4983: 4979: 4976: 4974: 4971: 4969: 4966: 4964: 4961: 4960: 4958: 4954: 4948: 4945: 4943: 4940: 4938: 4935: 4933: 4930: 4929: 4927: 4923: 4915: 4912: 4911: 4910: 4907: 4905: 4902: 4900: 4897: 4895: 4892: 4890: 4887: 4885: 4881: 4879: 4876: 4875: 4873: 4869: 4863: 4860: 4858: 4855: 4853: 4850: 4848: 4845: 4843: 4840: 4838: 4835: 4833: 4830: 4828: 4825: 4823: 4820: 4819: 4817: 4813: 4807: 4804: 4802: 4799: 4797: 4794: 4792: 4789: 4787: 4784: 4780: 4777: 4775: 4772: 4770: 4767: 4766: 4765: 4762: 4761: 4759: 4757:Decomposition 4755: 4749: 4746: 4744: 4741: 4739: 4736: 4734: 4731: 4729: 4726: 4724: 4721: 4720: 4718: 4716: 4712: 4706: 4703: 4701: 4698: 4695: 4693: 4690: 4687: 4685: 4682: 4679: 4677: 4674: 4673: 4671: 4667: 4661: 4658: 4656: 4653: 4651: 4648: 4646: 4643: 4641: 4638: 4636: 4633: 4631: 4628: 4627: 4625: 4621: 4615: 4612: 4610: 4607: 4605: 4602: 4600: 4597: 4595: 4592: 4590: 4587: 4585: 4582: 4580: 4577: 4575: 4572: 4570: 4567: 4566: 4564: 4560: 4556: 4552: 4545: 4540: 4538: 4533: 4531: 4526: 4525: 4522: 4516: 4515: 4514:3-540-42248-X 4511: 4506: 4503: 4500: 4496: 4493: 4490: 4486: 4483: 4481: 4480:0-7204-0762-1 4477: 4474: 4470: 4468: 4467:0-444-86308-7 4464: 4460: 4456: 4453: 4452: 4444: 4442:3-540-42248-X 4438: 4434: 4430: 4426: 4420: 4417: 4410: 4408: 4406: 4402: 4397: 4392: 4388: 4384: 4380: 4376: 4373: 4368: 4366: 4362: 4358: 4354: 4350: 4346: 4341: 4335: 4330: 4326: 4307: 4304: 4301: 4298: 4291: 4285: 4279: 4276: 4270: 4262: 4258: 4252: 4247: 4243: 4239: 4233: 4227: 4220: 4219: 4218: 4216: 4195: 4192: 4189: 4179: 4175: 4164: 4163: 4162: 4160: 4156: 4152: 4148: 4144: 4140: 4136: 4132: 4128: 4126: 4122: 4118: 4115: 4111: 4108: 4104: 4100: 4096: 4092: 4084: 4082: 4080: 4075: 4071: 4067: 4063: 4041: 4035: 4032: 4027: 4023: 4017: 4012: 4008: 4004: 3992: 3991: 3990: 3988: 3984: 3977: 3973: 3969: 3965: 3961: 3939: 3933: 3930: 3925: 3921: 3915: 3910: 3906: 3902: 3899: 3892: 3891: 3890: 3888: 3884: 3882: 3878: 3873: 3871: 3850: 3846: 3842: 3832: 3829: 3825: 3821: 3818: 3811: 3810: 3809: 3806: 3802: 3799: 3794: 3790: 3785: 3781: 3776: 3772: 3769: 3748: 3744: 3733: 3730: 3726: 3722: 3719: 3712: 3711: 3710: 3707: 3703: 3697: 3693: 3689: 3684: 3682: 3678: 3674: 3670: 3666: 3662: 3660: 3656: 3636: 3633: 3629: 3626: 3623: 3617: 3602: 3601: 3600: 3598: 3594: 3590: 3586: 3582: 3578: 3574: 3566: 3550: 3544: 3538: 3535: 3531: 3527: 3523: 3517: 3512: 3508: 3504: 3500: 3486: 3480: 3477: 3472: 3468: 3462: 3457: 3453: 3438: 3437: 3436: 3433: 3429: 3423: 3419: 3415: 3411: 3407: 3404: 3400: 3395: 3391: 3369: 3363: 3360: 3355: 3351: 3345: 3340: 3336: 3328: 3327: 3326: 3306: 3300: 3297: 3292: 3288: 3282: 3277: 3273: 3265: 3264: 3263: 3260: 3256: 3250: 3246: 3242: 3238: 3217: 3213: 3209: 3200: 3197: 3194: 3191: 3186: 3182: 3172: 3153: 3152: 3151: 3149: 3145: 3140: 3136: 3130: 3126: 3122: 3118: 3094: 3090: 3083: 3077: 3072: 3068: 3060: 3059: 3058: 3055: 3051: 3045: 3041: 3037: 3032: 3028: 3022: 3018: 3010: 3008: 3004: 2977: 2973: 2969: 2961: 2955: 2951: 2943: 2942: 2941: 2939: 2935: 2916: 2913: 2910: 2904: 2901: 2898: 2895: 2892: 2885: 2884: 2883: 2882: 2860: 2854: 2851: 2846: 2842: 2836: 2831: 2827: 2822: 2816: 2810: 2807: 2802: 2798: 2792: 2787: 2783: 2775: 2774: 2773: 2771: 2764: 2760: 2753: 2749: 2745: 2741: 2739: 2734: 2732: 2728: 2721: 2717: 2714: 2711: 2689: 2683: 2680: 2675: 2671: 2665: 2660: 2656: 2649: 2646: 2643: 2636: 2635: 2634: 2632: 2625: 2621: 2601: 2595: 2589: 2586: 2581: 2577: 2571: 2566: 2562: 2554: 2553: 2552: 2550: 2543: 2539: 2535: 2531: 2527: 2524: 2520: 2516: 2510: 2508: 2506: 2499: 2495: 2491: 2489: 2482: 2477: 2457: 2451: 2448: 2443: 2439: 2430: 2425: 2421: 2414: 2407: 2406: 2405: 2378: 2372: 2369: 2361: 2357: 2351: 2346: 2342: 2331: 2319: 2306: 2302: 2298: 2295: 2288: 2287: 2286: 2284: 2280: 2278: 2274: 2269: 2267: 2248: 2242: 2236: 2233: 2225: 2221: 2212: 2208: 2199: 2194: 2190: 2186: 2173: 2167: 2164: 2159: 2155: 2146: 2141: 2137: 2116: 2110: 2107: 2102: 2098: 2089: 2084: 2080: 2065: 2064: 2063: 2036: 2030: 2027: 2019: 2015: 2009: 2004: 2000: 1989: 1983: 1977: 1971: 1968: 1963: 1959: 1950: 1945: 1941: 1933: 1932: 1931: 1911: 1903: 1899: 1892: 1887: 1884: 1881: 1849: 1848: 1847: 1845: 1840: 1837: 1833: 1828: 1824: 1819: 1815: 1811: 1810: 1804: 1800: 1795: 1791: 1786: 1782: 1776: 1772: 1753: 1748: 1742: 1737: 1732: 1727: 1722: 1715: 1708: 1704: 1698: 1693: 1688: 1681: 1676: 1671: 1666: 1661: 1654: 1649: 1644: 1637: 1633: 1627: 1620: 1615: 1610: 1605: 1598: 1594: 1587: 1578: 1577: 1576: 1574: 1570: 1551: 1546: 1540: 1535: 1530: 1525: 1520: 1513: 1506: 1503: 1499: 1493: 1486: 1483: 1479: 1471: 1468: 1464: 1456: 1451: 1446: 1441: 1436: 1429: 1422: 1419: 1415: 1409: 1402: 1398: 1390: 1386: 1378: 1371: 1368: 1364: 1358: 1351: 1347: 1339: 1335: 1328: 1319: 1318: 1317: 1298: 1294: 1283: 1280: 1276: 1272: 1269: 1262: 1261: 1260: 1258: 1250: 1232: 1228: 1217: 1214: 1210: 1206: 1200: 1194: 1183: 1179: 1173: 1168: 1164: 1156: 1155: 1154: 1151: 1147: 1143: 1139: 1135: 1132:. Thus, when 1131: 1127: 1126:countable set 1123: 1115: 1099: 1093: 1087: 1076: 1072: 1066: 1061: 1057: 1047: 1041: 1030: 1026: 1020: 1015: 1011: 1003: 1002: 1001: 984: 979: 975: 971: 966: 960: 950: 939: 931: 924: 923: 922: 920: 916: 912: 909: 905: 901: 898: 894: 890: 870: 864: 849: 843: 832: 826: 818: 814: 810: 804: 796: 786: 785: 784: 781: 777: 771: 767: 745: 739: 728: 724: 718: 713: 709: 701: 700: 699: 697: 693: 689: 684: 680: 676: 672: 667: 663: 658: 654: 649: 645: 639: 635: 632:is a family { 630: 626: 620: 616: 612: 611:cross-section 607: 594: 589: 585: 576: 572: 554: 550: 519: 516: 513: 499: 495: 487: 484: 481: 467: 453: 449: 444: 430: 429: 428: 426: 421: 417: 396: 392: 388: 385: 379: 369: 364: 360: 352: 351: 350: 348: 327: 324: 321: 318: 315: 305: 301: 290: 289: 288: 285: 281: 275: 271: 267: 263: 259: 255: 251: 249: 245: 241: 237: 233: 229: 225: 221: 217: 213: 209: 205: 201: 198: 194: 190: 186: 182: 178: 174: 170: 152: 146: 143: 140: 132: 127: 123: 115: 114: 113: 111: 107: 104: 100: 97: 93: 85: 83: 81: 77: 73: 69: 68:George Mackey 64: 62: 57: 55: 51: 47: 43: 39: 35: 31: 27: 23: 19: 5064:Applications 4894:Disk algebra 4795: 4748:Spectral gap 4623:Main results 4507: 4488: 4485:G. W. Mackey 4472: 4471:J. Dixmier, 4458: 4428: 4419: 4400: 4395: 4390: 4386: 4382: 4378: 4374: 4371: 4369: 4360: 4356: 4352: 4348: 4344: 4339: 4333: 4328: 4324: 4322: 4214: 4212: 4158: 4154: 4150: 4146: 4142: 4138: 4134: 4130: 4129: 4120: 4116: 4102: 4098: 4090: 4088: 4078: 4073: 4069: 4065: 4061: 4059: 3986: 3982: 3975: 3971: 3967: 3963: 3959: 3957: 3886: 3885: 3880: 3876: 3874: 3869: 3867: 3804: 3800: 3797: 3792: 3788: 3783: 3779: 3774: 3770: 3767: 3765: 3705: 3701: 3695: 3691: 3687: 3685: 3680: 3676: 3672: 3668: 3664: 3663: 3658: 3654: 3652: 3596: 3592: 3588: 3580: 3576: 3572: 3570: 3431: 3427: 3421: 3417: 3413: 3412: 3408: 3402: 3398: 3393: 3389: 3387: 3324: 3258: 3254: 3248: 3244: 3240: 3236: 3234: 3147: 3143: 3138: 3134: 3128: 3124: 3120: 3114: 3053: 3049: 3043: 3039: 3030: 3026: 3020: 3016: 3014: 3005: 3002: 2937: 2933: 2931: 2878: 2769: 2762: 2758: 2751: 2747: 2743: 2742: 2737: 2735: 2730: 2726: 2719: 2715: 2712: 2709: 2707: 2630: 2623: 2619: 2617: 2548: 2541: 2537: 2533: 2529: 2525: 2518: 2517: 2514: 2504: 2497: 2493: 2492: 2487: 2480: 2479:This allows 2478: 2475: 2403: 2282: 2281: 2276: 2272: 2270: 2266:decomposable 2265: 2263: 2061: 1929: 1841: 1835: 1831: 1826: 1822: 1817: 1813: 1807: 1802: 1798: 1793: 1789: 1784: 1780: 1774: 1770: 1768: 1568: 1566: 1315: 1256: 1254: 1149: 1145: 1141: 1137: 1133: 1121: 1119: 999: 918: 914: 913: 910: 903: 899: 896: 892: 891: 888: 779: 775: 769: 765: 763: 691: 687: 682: 678: 674: 670: 665: 661: 656: 652: 647: 643: 637: 633: 628: 624: 618: 614: 610: 608: 541: 424: 419: 415: 413: 346: 344: 283: 279: 273: 269: 265: 261: 257: 253: 252: 239: 235: 231: 227: 223: 211: 204:Polish space 196: 184: 176: 172: 168: 167: 109: 105: 98: 91: 89: 65: 58: 49: 29: 25: 15: 5091:Heat kernel 4791:Compression 4676:Isospectral 4473:C* algebras 4393:such that π 3868:represents 2279:. In fact, 1128:and μ is a 177:Borel space 61:C*-algebras 18:mathematics 5176:Categories 4769:Continuous 4584:C*-algebra 4579:B*-algebra 4455:J. Dixmier 4411:References 4217:such that 4095:C*-algebra 3970:so that Z( 3889:. Suppose 3709:such that 2708:such that 2618:To assert 2521:. For any 1846:, that is 651:such that 349:such that 254:Definition 189:Borel sets 34:direct sum 4555:-algebras 4302:∈ 4296:∀ 4280:μ 4259:π 4253:⊕ 4244:∫ 4228:π 4193:∈ 4176:π 4125:separable 4036:μ 4018:⊕ 4009:∫ 3934:μ 3916:⊕ 3907:∫ 3833:∈ 3826:⨁ 3734:∈ 3727:∑ 3630:∩ 3583:) be the 3539:μ 3518:⊕ 3509:∫ 3481:μ 3463:⊕ 3454:∫ 3364:μ 3346:⊕ 3337:∫ 3301:μ 3283:⊕ 3274:∫ 3235:where W*( 3198:∈ 3173:⁡ 3084:⁡ 3078:⊆ 2956:ϕ 2914:− 2908:→ 2902:− 2893:φ 2855:ν 2837:⊕ 2828:∫ 2811:μ 2793:⊕ 2784:∫ 2684:μ 2666:⊕ 2657:∫ 2653:→ 2590:μ 2572:⊕ 2563:∫ 2452:μ 2440:λ 2431:⊕ 2422:∫ 2418:↦ 2415:λ 2404:given by 2373:μ 2352:⊕ 2343:∫ 2332:⁡ 2326:→ 2312:∞ 2307:μ 2296:ϕ 2237:μ 2200:⊕ 2191:∫ 2168:μ 2147:⊕ 2138:∫ 2111:μ 2090:⊕ 2081:∫ 2031:μ 2010:⊕ 2001:∫ 1990:⁡ 1984:∈ 1972:μ 1951:⊕ 1942:∫ 1915:∞ 1909:‖ 1896:‖ 1893:⁡ 1885:∈ 1743:⋱ 1738:⋮ 1733:⋯ 1728:⋮ 1723:⋮ 1716:⋯ 1705:λ 1699:⋯ 1682:⋯ 1677:⋮ 1672:⋱ 1667:⋮ 1662:⋮ 1655:⋯ 1645:⋯ 1634:λ 1621:⋯ 1611:⋯ 1595:λ 1541:⋱ 1536:⋮ 1531:⋯ 1526:⋮ 1521:⋮ 1514:⋯ 1494:⋯ 1457:⋯ 1452:⋮ 1447:⋱ 1442:⋮ 1437:⋮ 1430:⋯ 1410:⋯ 1379:⋯ 1359:⋯ 1284:∈ 1277:⨁ 1218:∈ 1211:⨁ 1207:≅ 1195:μ 1174:⊕ 1165:∫ 1088:ν 1067:⊕ 1058:∫ 1054:→ 1042:μ 1021:⊕ 1012:∫ 961:ν 951:μ 935:↦ 865:μ 856:⟩ 824:⟨ 815:∫ 808:⟩ 794:⟨ 740:μ 719:⊕ 710:∫ 586:ℓ 551:ℓ 520:ω 496:ℓ 488:ω 389:∈ 328:ω 325:≤ 319:≤ 181:σ-algebra 128:μ 5156:Weyl law 5101:Lax pair 5048:Examples 4882:With an 4801:Discrete 4779:Residual 4715:Spectrum 4700:operator 4692:operator 4684:operator 4599:Spectrum 4427:(2001), 4361:disjoint 3985:) where 3637:′ 3571:Suppose 3532:′ 3501:′ 669:for all 248:σ-finite 228:standard 220:null set 197:standard 4697:Unitary 4131:Theorem 3887:Theorem 3665:Example 3414:Theorem 2744:Theorem 2519:Theorem 2494:Theorem 2283:Theorem 1116:Example 915:Theorem 4681:Normal 4512:  4478:  4465:  4439:  4149:) for 4133:. Let 4079:factor 3681:factor 3585:center 3416:. If { 3243:. If { 2932:where 2761:) and 2436:  2367:  2205:  2152:  2095:  2025:  1956:  897:fibers 893:Remark 573:; all 414:where 256:. Let 4774:Point 4112:of a 3766:then 3686:When 3679:is a 3653:Then 3057:with 3015:Let { 1788:with 1124:is a 242:is a 226:is a 210:μ on 4705:Unit 4553:and 4510:ISBN 4476:ISBN 4463:ISBN 4437:ISBN 3962:and 3388:for 1912:< 1797:∈ L( 613:of { 485:< 264:on ( 214:, a 24:, a 20:and 4457:, 4377:of 4337:, π 4327:of 4213:of 4089:If 3787:of 3587:of 2507:). 1259:on 187:as 183:of 78:of 28:or 16:In 5178:: 4497:, 4487:, 4461:, 4435:, 4431:, 4407:. 4355:− 4351:∈ 4347:, 4153:∈ 4081:. 4068:, 4064:∈ 3704:∈ 3683:. 3599:: 3430:∈ 3406:. 3397:∈ 3257:∈ 3150:, 3146:∈ 3137:∈ 3132:} 3052:∈ 3029:∈ 2936:, 2268:. 1839:. 1783:∈ 1403:22 1391:21 1352:12 1340:11 1136:= 778:∈ 690:, 673:∈ 660:∈ 646:∈ 627:∈ 609:A 282:∈ 250:. 238:− 82:. 5087:) 5083:( 4984:) 4980:( 4543:e 4536:t 4529:v 4401:x 4396:x 4391:Q 4387:Q 4383:A 4379:A 4375:Q 4357:N 4353:X 4349:y 4345:x 4340:y 4334:x 4329:X 4325:N 4308:. 4305:A 4299:a 4292:, 4289:) 4286:x 4283:( 4277:d 4274:) 4271:a 4268:( 4263:x 4248:X 4240:= 4237:) 4234:a 4231:( 4215:A 4196:X 4190:x 4186:} 4180:x 4172:{ 4159:X 4155:A 4151:a 4147:a 4143:H 4139:A 4135:A 4121:G 4117:G 4103:A 4099:A 4091:A 4074:x 4070:A 4066:X 4062:x 4045:) 4042:x 4039:( 4033:d 4028:x 4024:A 4013:X 4005:= 4001:A 3987:X 3983:X 3981:( 3979:μ 3976:L 3972:A 3968:H 3964:A 3960:H 3943:) 3940:x 3937:( 3931:d 3926:x 3922:H 3911:X 3903:= 3900:H 3881:A 3877:A 3870:A 3851:i 3847:E 3843:A 3837:N 3830:i 3822:= 3819:A 3805:i 3801:E 3798:A 3793:i 3789:E 3784:i 3780:H 3775:i 3771:E 3768:A 3749:i 3745:E 3738:N 3731:i 3723:= 3720:1 3706:N 3702:i 3699:} 3696:i 3692:E 3688:A 3677:A 3673:A 3669:H 3659:A 3657:( 3655:Z 3634:A 3627:A 3624:= 3621:) 3618:A 3615:( 3611:Z 3597:A 3593:A 3589:A 3581:A 3579:( 3577:Z 3573:A 3551:. 3548:) 3545:x 3542:( 3536:d 3528:x 3524:A 3513:X 3505:= 3496:] 3490:) 3487:x 3484:( 3478:d 3473:x 3469:A 3458:X 3448:[ 3432:X 3428:x 3425:} 3422:x 3418:A 3403:x 3399:A 3394:x 3390:T 3373:) 3370:x 3367:( 3361:d 3356:x 3352:T 3341:X 3310:) 3307:x 3304:( 3298:d 3293:x 3289:A 3278:X 3259:X 3255:x 3252:} 3249:x 3245:A 3241:S 3237:S 3218:x 3214:A 3210:= 3207:) 3204:} 3201:D 3195:S 3192:: 3187:x 3183:S 3179:{ 3176:( 3167:* 3163:W 3148:X 3144:x 3139:X 3135:x 3129:x 3125:A 3121:D 3100:) 3095:x 3091:H 3087:( 3081:L 3073:x 3069:A 3054:X 3050:x 3047:} 3044:x 3040:A 3038:{ 3031:X 3027:x 3024:} 3021:x 3017:H 2978:x 2974:H 2970:= 2965:) 2962:x 2959:( 2952:K 2938:F 2934:E 2917:F 2911:Y 2905:E 2899:X 2896:: 2864:) 2861:y 2858:( 2852:d 2847:y 2843:K 2832:Y 2823:, 2820:) 2817:x 2814:( 2808:d 2803:x 2799:H 2788:X 2770:Y 2768:( 2766:ν 2763:L 2759:X 2757:( 2755:μ 2752:L 2748:A 2738:X 2731:A 2727:X 2725:( 2723:μ 2720:L 2716:U 2713:A 2710:U 2693:) 2690:x 2687:( 2681:d 2676:x 2672:H 2661:X 2650:H 2647:: 2644:U 2631:X 2629:( 2627:μ 2624:L 2620:A 2602:. 2599:) 2596:x 2593:( 2587:d 2582:x 2578:H 2567:X 2549:X 2547:( 2545:μ 2542:L 2538:X 2534:X 2530:H 2526:A 2505:X 2503:( 2501:μ 2498:L 2488:X 2486:( 2484:μ 2481:L 2461:) 2458:x 2455:( 2449:d 2444:x 2426:X 2387:) 2382:) 2379:x 2376:( 2370:d 2362:x 2358:H 2347:X 2337:( 2329:L 2323:) 2320:X 2317:( 2303:L 2299:: 2277:X 2273:C 2249:. 2246:) 2243:x 2240:( 2234:d 2231:) 2226:x 2222:s 2218:( 2213:x 2209:T 2195:X 2187:= 2182:) 2177:) 2174:x 2171:( 2165:d 2160:x 2156:s 2142:X 2132:( 2125:] 2120:) 2117:x 2114:( 2108:d 2103:x 2099:T 2085:X 2075:[ 2045:) 2040:) 2037:x 2034:( 2028:d 2020:x 2016:H 2005:X 1995:( 1987:L 1981:) 1978:x 1975:( 1969:d 1964:x 1960:T 1946:X 1904:x 1900:T 1888:X 1882:x 1877:p 1874:u 1871:s 1868:- 1865:s 1862:s 1859:e 1836:n 1832:X 1827:x 1823:H 1818:n 1814:X 1803:x 1799:H 1794:x 1790:T 1785:X 1781:x 1778:} 1775:x 1771:T 1754:. 1749:] 1709:n 1694:0 1689:0 1650:0 1638:2 1628:0 1616:0 1606:0 1599:1 1588:[ 1552:. 1547:] 1507:n 1504:n 1500:T 1487:2 1484:n 1480:T 1472:1 1469:n 1465:T 1423:n 1420:2 1416:T 1399:T 1387:T 1372:n 1369:1 1365:T 1348:T 1336:T 1329:[ 1299:k 1295:H 1288:N 1281:k 1273:= 1270:H 1257:T 1233:k 1229:H 1222:N 1215:k 1204:) 1201:x 1198:( 1191:d 1184:x 1180:H 1169:X 1150:k 1146:H 1142:N 1138:N 1134:X 1122:X 1100:. 1097:) 1094:x 1091:( 1084:d 1077:x 1073:H 1062:X 1051:) 1048:x 1045:( 1038:d 1031:x 1027:H 1016:X 985:s 980:2 976:/ 972:1 967:) 957:d 947:d 940:( 932:s 919:X 904:x 900:H 874:) 871:x 868:( 861:d 853:) 850:x 847:( 844:t 840:| 836:) 833:x 830:( 827:s 819:X 811:= 805:t 801:| 797:s 780:X 776:x 773:} 770:x 766:H 749:) 746:x 743:( 736:d 729:x 725:H 714:X 692:t 688:s 683:n 679:X 675:X 671:x 666:x 662:H 657:x 653:s 648:X 644:x 641:} 638:x 634:s 629:X 625:x 622:} 619:x 615:H 595:. 590:2 555:2 517:= 514:n 500:2 482:n 468:n 463:C 454:{ 450:= 445:n 440:H 425:n 420:n 416:H 397:n 393:X 386:x 380:n 375:H 370:= 365:x 361:H 347:X 322:n 316:1 312:} 306:n 302:X 298:{ 284:X 280:x 277:} 274:x 270:H 266:X 258:X 240:E 236:X 232:E 224:X 212:X 185:X 173:X 153:. 150:) 147:H 144:, 141:X 138:( 133:2 124:L 110:H 106:H 99:X 92:L

Index

mathematics
functional analysis
direct sum
Hilbert spaces
von Neumann algebras
John von Neumann
Artin–Wedderburn theorem
C*-algebras
George Mackey
systems of imprimitivity
induced representations
locally compact separable groups
measurable space
separable Hilbert space
σ-algebra
Borel sets
topological space
if and only if
Polish space
countably additive measure
measurable set
null set
standard Borel space
σ-finite
square summable sequences
separable Hilbert spaces
almost everywhere
countable set
discrete measure
block diagonal

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