Knowledge

Character theory

Source 📝

4088: 3762: 4083:{\displaystyle {\begin{aligned}\left\langle \theta ^{G},\psi ^{G}\right\rangle &=\left\langle \left(\theta ^{G}\right)_{K},\psi \right\rangle \\&=\sum _{t\in T}\left\langle \left(\left_{t^{-1}Ht\cap K}\right)^{K},\psi \right\rangle \\&=\sum _{t\in T}\left\langle \left(\theta ^{t}\right)_{t^{-1}Ht\cap K},\psi _{t^{-1}Ht\cap K}\right\rangle ,\end{aligned}}} 2262: 2070: 2538:, have the same character table. Brauer asked whether the character table, together with the knowledge of how the powers of elements of its conjugacy classes are distributed, determines a finite group up to isomorphism. In 1964, this was answered in the negative by 1912: 2095: 495: 5162: 3370: 3671: 1463: 1317: 1163: 3022: 2742: 954: 4689: 894: 1955: 4608: 4432: 299: 1009: 4885: 1634: 1569:. Each entry in the first row is therefore 1. Similarly, it is customary to label the first column by the identity. Therefore, the first column contains the degree of each irreducible character. 3767: 2257:{\displaystyle \sum _{\chi _{i}}\chi _{i}(g){\overline {\chi _{i}(h)}}={\begin{cases}\left|C_{G}(g)\right|,&{\mbox{ if }}g,h{\mbox{ are conjugate }}\\0&{\mbox{ otherwise.}}\end{cases}}} 1807: 3214: 2842: 751: 1397: 4815: 4759: 2643: 2597: 1490:
in a compact form. Each row is labelled by an irreducible representation and the entries in the row are the characters of the representation on the respective conjugacy class of
4216:
One can find analogs or generalizations of statements about dimensions to statements about characters or representations. A sophisticated example of this occurs in the theory of
3534: 398: 2486: 5283: 5060: 5036: 5012: 4941: 4913: 4508: 4460: 5072: 3453:, but is a powerful tool in the character theory and representation theory of finite groups. Its basic form concerns the way a character (or module) induced from a subgroup 3233: 4968: 4786: 4535: 4346: 5236: 3550: 1541: 5256: 5189: 133:(a purely group-theoretic proof of Burnside's theorem has since been found, but that proof came over half a century after Burnside's original proof), and a theorem of 1567: 5209: 4988: 4484: 4366: 4299: 1169: 1015: 2949: 2348:
is given by the sum of the squares of the entries of the first column (the degrees of the irreducible characters). More generally, the sum of the squares of the
4729: 4709: 4319: 4275: 2499:, that the prime divisors of the orders of the elements of each conjugacy class of a finite group can be deduced from its character table (an observation of 3386:
This alternative description of the induced character sometimes allows explicit computation from relatively little information about the embedding of
2648: 3732:
Mackey decomposition, in conjunction with Frobenius reciprocity, yields a well-known and useful formula for the inner product of two class functions
900: 5620: 5562:. Graduate Texts in Mathematics. Vol. 42. Translated from the second French edition by Leonard L. Scott. New York-Heidelberg: Springer-Verlag. 4617: 840: 118: 74: 5575: 5541: 5518: 5481: 5443: 2065:{\displaystyle \left\langle \chi _{i},\chi _{j}\right\rangle ={\begin{cases}0&{\mbox{ if }}i\neq j,\\1&{\mbox{ if }}i=j.\end{cases}}} 5063: 2311:
are conjugate iff they are in the same column of the character table, this implies that the columns of the character table are orthogonal.
4543: 77:
entirely based on the characters, and without any explicit matrix realization of representations themselves. This is possible because a
101:
developed a powerful theory of characters in this case as well. Many deep theorems on the structure of finite groups use characters of
5500: 117:
encode many important properties of a group and can thus be used to study its structure. Character theory is an essential tool in the
1775:
The character table is always square, because the number of irreducible representations is equal to the number of conjugacy classes.
4374: 241: 5466: 960: 4823: 676: 3721:. There is a similar formula for the restriction of an induced module to a subgroup, which holds for representations over any 129:
involves intricate calculations with character values. Easier, but still essential, results that use character theory include
5415: 5169: 5427: 3434: 2496: 1907:{\displaystyle \left\langle \alpha ,\beta \right\rangle :={\frac {1}{|G|}}\sum _{g\in G}\alpha (g){\overline {\beta (g)}}} 1784: 1578: 1333: 572: 349: 138: 102: 30:
This article is about the use of the term character theory in mathematics. For related senses of the word character, see
146: 3158: 5419: 5294: 2352:
of the entries in any column gives the order of the centralizer of an element of the corresponding conjugacy class.
337: 114: 4236: 2751: 1949:
for the space of class-functions, and this yields the orthogonality relation for the rows of the character table:
126: 2908: 4173: 2428:
is finite, then since the character table is square and has as many rows as conjugacy classes, it follows that
778: 558: 170: 94: 1769: 490:{\displaystyle \ker \chi _{\rho }:=\left\lbrace g\in G\mid \chi _{\rho }(g)=\chi _{\rho }(1)\right\rbrace ,} 31: 3086:. The defining formula of Frobenius reciprocity can be extended to general complex-valued class functions. 626:
is the degree (that is, the dimension of the associated vector space) of the representation with character
4916: 4791: 4734: 4248: 3102: 2602: 2556: 1500: 534: 309: 62: 54: 3491: 2921: 2865: 2364: 554: 5312:
in 1937, yields information about the restriction of a complex irreducible character of a finite group
5157:{\displaystyle \chi _{\rho }(H)=\sum _{\lambda }m_{\lambda }e^{\lambda (H)},\quad H\in {\mathfrak {h}}} 4117:
are linear characters, in which case all the inner products appearing in the right hand sum are either
3365:{\displaystyle \theta ^{G}(h)=\sum _{i\ :\ t_{i}ht_{i}^{-1}\in H}\theta \left(t_{i}ht_{i}^{-1}\right).} 2443: 130: 5264: 5041: 5017: 4993: 4922: 4894: 4489: 4441: 773: 635: 199: 69:. The character carries the essential information about the representation in a more condensed form. 66: 50: 4761:. If we have a Lie group representation and an associated Lie algebra representation, the character 2171: 2000: 807:. Furthermore, in this case, the degrees of the irreducible characters are divisors of the order of 4946: 4764: 4513: 4324: 4252: 4217: 3666:{\displaystyle \left(\theta ^{G}\right)_{K}=\sum _{t\in T}\left(\left_{t^{-1}Ht\cap K}\right)^{K},} 2845: 2410: 1357: 177: 90: 58: 5214: 3417:
The general technique of character induction and later refinements found numerous applications in
5299: 3722: 2744:
defines a new linear representation. This gives rise to a group of linear characters, called the
2321:
Constructing the complete character table when only some of the irreducible characters are known.
1458:{\displaystyle \rho \otimes \rho =\left(\rho \wedge \rho \right)\oplus {\textrm {Sym}}^{2}\rho .} 122: 1511: 5571: 5537: 5514: 5496: 5477: 5457: 5439: 5323: 5241: 5174: 2861: 2553:, since the tensor product of 1-dimensional vector spaces is again 1-dimensional. That is, if 2511: 2324:
Finding the orders of the centralizers of representatives of the conjugacy classes of a group.
1946: 1931: 754: 653: 576: 1312:{\displaystyle \chi _{{\scriptscriptstyle {\rm {{Sym}^{2}}}}\rho }(g)={\tfrac {1}{2}}\!\left} 1158:{\displaystyle \chi _{{\scriptscriptstyle {\rm {{Alt}^{2}}}}\rho }(g)={\tfrac {1}{2}}\!\left} 5563: 5431: 4228: 4188: 2849: 2515: 1546: 1391: 1369: 788: 579:, then the corresponding character is the sum of the characters of those subrepresentations. 5585: 5453: 5194: 4973: 4469: 4351: 4284: 3017:{\displaystyle \langle \theta ^{G},\chi \rangle _{G}=\langle \theta ,\chi _{H}\rangle _{H}} 5581: 5449: 5305: 2745: 1473: 800: 522: 389: 70: 5513:(Corrected reprint of the 1976 original, published by Academic Press. ed.). Dover. 5556: 5529: 5309: 4714: 4694: 4304: 4260: 4213:. Accordingly, one can view the other values of the character as "twisted" dimensions. 3426: 3141: 2550: 2522: 2492: 2349: 1790: 1479: 1347: 619: 565: 518: 150: 134: 98: 78: 5474:
Moonshine beyond the Monster: The Bridge Connecting Algebra, Modular Forms and Physics
17: 5614: 4232: 2500: 2433: 1798: 5328: 5295:
Irreducible representation § Applications in theoretical physics and chemistry
3418: 2318:
Decomposing an unknown character as a linear combination of irreducible characters.
1640: 173: 142: 82: 42: 5285:
of the) character can be computed more explicitly by the Weyl character formula.
5551: 4463: 4221: 3430: 3383:, this value does not depend on the particular choice of coset representatives. 2737:{\displaystyle \rho _{1}\otimes \rho _{2}(g)=(\rho _{1}(g)\otimes \rho _{2}(g))} 2296: 2089:, applying the same inner product to the columns of the character table yields: 86: 38: 3097:, Frobenius later gave an explicit way to construct a matrix representation of 2870:
The characters discussed in this section are assumed to be complex-valued. Let
949:{\displaystyle \chi _{\rho \otimes \sigma }=\chi _{\rho }\cdot \chi _{\sigma }} 5604: 5567: 5435: 3422: 2539: 5461: 2929:
form an orthonormal basis for the space of complex-valued class functions of
4278: 3450: 3446: 2402:
is the intersection of the kernels of some of the irreducible characters of
1494:. The columns are labelled by (representatives of) the conjugacy classes of 4109:-double coset representatives, as before). This formula is often used when 3748:, whose utility lies in the fact that it only depends on how conjugates of 3394:, and is often useful for calculation of particular character tables. When 4684:{\displaystyle \chi _{\rho }(\operatorname {Ad} _{g}(X))=\chi _{\rho }(X)} 5495:, Graduate Texts in Mathematics, vol. 222 (2nd ed.), Springer, 5493:
Lie groups, Lie algebras, and representations: An elementary introduction
3726: 1945:. With respect to this inner product, the irreducible characters form an 889:{\displaystyle \chi _{\rho \oplus \sigma }=\chi _{\rho }+\chi _{\sigma }} 587: 3062: 5430:, Readings in Mathematics. Vol. 129. New York: Springer-Verlag. 4172:
One may interpret the character of a representation as the "twisted"
3421:
and elsewhere in mathematics, in the hands of mathematicians such as
525:. More precisely, the set of irreducible characters of a given group 4176:. Treating the character as a function of the elements of the group 5600: 2436:
iff each conjugacy class is a singleton iff the character table of
4603:{\displaystyle \chi _{\rho }(X)=\operatorname {Tr} (e^{\rho (X)})} 4156:
are both trivial characters, then the inner product simplifies to
3145: 3114:. This led to an alternative description of the induced character 2508: 3132:, it is only now necessary to describe its values on elements of 2314:
The orthogonality relations can aid many computations including:
1498:. It is customary to label the first row by the character of the 3461:
behaves on restriction back to a (possibly different) subgroup
2417:
is the intersection of the kernels of the linear characters of
4788:
of the Lie algebra representation is related to the character
4427:{\displaystyle \chi _{\rho }(g)=\operatorname {Tr} (\rho (g))} 294:{\displaystyle \chi _{\rho }(g)=\operatorname {Tr} (\rho (g))} 89:) by its character. The situation with representations over a 1004:{\displaystyle \chi _{\rho ^{*}}={\overline {\chi _{\rho }}}} 97:, so-called "modular representations", is more delicate, but 4880:{\displaystyle \chi _{\rho }(X)=\mathrm {X} _{\rho }(e^{X})} 3756:
intersect each other. The formula (with its derivation) is:
2507:
The character table does not in general determine the group
5302:, a combinatorial generalization of group-character theory. 4235:, and replacing the dimension with the character gives the 2363:
is simple) can be recognised from its character table. The
2250: 2058: 3725:, and has applications in a wide variety of algebraic and 3039:
and the rightmost inner product is for class functions of
557:
representations have the same characters. Over a field of
4231:
of an infinite-dimensional graded representation of the
2267:
where the sum is over all of the irreducible characters
3494: 3035:(the leftmost inner product is for class functions of 2241: 2225: 2209: 2037: 2009: 1486:
which encodes much useful information about the group
1222: 1179: 1068: 1025: 521:, that is, they each take a constant value on a given 5267: 5244: 5217: 5197: 5177: 5075: 5044: 5020: 4996: 4976: 4949: 4925: 4897: 4826: 4794: 4767: 4737: 4717: 4697: 4620: 4546: 4516: 4492: 4472: 4444: 4377: 4354: 4327: 4307: 4287: 4263: 3765: 3553: 3445:
The Mackey decomposition was defined and explored by
3236: 3161: 3128:. Since the induced character is a class function of 3120:. This induced character vanishes on all elements of 2952: 2754: 2651: 2605: 2559: 2446: 2098: 1958: 1810: 1581: 1549: 1514: 1400: 1172: 1018: 963: 903: 843: 679: 401: 244: 4125:, depending on whether or not the linear characters 1629:{\displaystyle C_{3}=\langle u\mid u^{3}=1\rangle ,} 500:
which is precisely the kernel of the representation
356:; in characteristic zero this is equal to the value 5555: 5534:Representations and Characters of Groups (2nd ed.) 5277: 5250: 5230: 5203: 5183: 5156: 5054: 5030: 5006: 4982: 4962: 4935: 4907: 4879: 4809: 4780: 4753: 4723: 4703: 4683: 4602: 4529: 4502: 4478: 4454: 4426: 4360: 4340: 4313: 4293: 4269: 4082: 3665: 3528: 3364: 3208: 3016: 2836: 2736: 2637: 2591: 2480: 2256: 2064: 1906: 1628: 1561: 1535: 1457: 1311: 1157: 1003: 948: 888: 745: 489: 293: 3402:, the induced character obtained is known as the 2464: 2460: 1233: 1079: 3209:{\displaystyle G=Ht_{1}\cup \ldots \cup Ht_{n},} 795:, then the number of irreducible characters of 8: 3005: 2985: 2973: 2953: 2856:Induced characters and Frobenius reciprocity 2837:{\displaystyle (g)=\chi _{1}(g)\chi _{2}(g)} 1620: 1595: 746:{\displaystyle {\frac {\chi (x)}{\chi (1)}}} 4817:of the group representation by the formula 3043:). Since the restriction of a character of 3124:which are not conjugate to any element of 61:that associates to each group element the 5269: 5268: 5266: 5243: 5222: 5216: 5196: 5176: 5148: 5147: 5122: 5112: 5102: 5080: 5074: 5046: 5045: 5043: 5022: 5021: 5019: 4998: 4997: 4995: 4975: 4954: 4948: 4927: 4926: 4924: 4899: 4898: 4896: 4868: 4855: 4850: 4831: 4825: 4801: 4796: 4793: 4772: 4766: 4745: 4744: 4736: 4716: 4696: 4666: 4638: 4625: 4619: 4582: 4551: 4545: 4521: 4515: 4494: 4493: 4491: 4471: 4446: 4445: 4443: 4382: 4376: 4368:is defined precisely as for any group as 4353: 4332: 4326: 4306: 4286: 4262: 4243:Characters of Lie groups and Lie algebras 4045: 4040: 4010: 4005: 3995: 3969: 3938: 3911: 3906: 3896: 3865: 3834: 3824: 3792: 3779: 3766: 3764: 3654: 3627: 3622: 3612: 3586: 3573: 3563: 3552: 3505: 3493: 3345: 3340: 3327: 3298: 3293: 3280: 3263: 3241: 3235: 3197: 3175: 3160: 3065:combination of irreducible characters of 3008: 2998: 2976: 2960: 2951: 2819: 2800: 2775: 2762: 2753: 2716: 2694: 2669: 2656: 2650: 2629: 2610: 2604: 2583: 2564: 2558: 2488:iff each irreducible character is linear. 2473: 2465: 2455: 2447: 2445: 2340:can be deduced from its character table: 2240: 2224: 2208: 2183: 2166: 2142: 2135: 2120: 2108: 2103: 2097: 2036: 2008: 1995: 1981: 1968: 1957: 1883: 1859: 1847: 1839: 1833: 1809: 1608: 1586: 1580: 1548: 1513: 1443: 1437: 1436: 1399: 1295: 1282: 1269: 1249: 1221: 1194: 1183: 1181: 1180: 1178: 1177: 1171: 1141: 1128: 1115: 1095: 1067: 1040: 1029: 1027: 1026: 1024: 1023: 1017: 990: 984: 973: 968: 962: 940: 927: 908: 902: 880: 867: 848: 842: 711: 693: 678: 593:, then the result is also a character of 464: 442: 412: 400: 249: 243: 5384: 5382: 3469:, and makes use of the decomposition of 1649: 5558:Linear Representations of Finite Groups 5356: 5062:can easily be computed in terms of the 4486:a finite-dimensional representation of 4301:a finite-dimensional representation of 4239:for each element of the Monster group. 2911:showed how to construct a character of 5389: 5367:, Springer-Verlag, 2012, Chap. 8, p392 5343:) is a real number for all characters 5038:. The restriction of the character to 3055:, this definition makes it clear that 2925:. Since the irreducible characters of 834:. Then the following identities hold: 119:classification of finite simple groups 75:representation theory of finite groups 5424:Representation theory. A first course 4191:is the dimension of the space, since 564:, two representations are isomorphic 541:-vector space of all class functions 7: 5401: 4810:{\displaystyle \mathrm {X} _{\rho }} 4754:{\displaystyle X\in {\mathfrak {g}}} 3544:, then Mackey's formula states that 2638:{\displaystyle \rho _{2}:G\to V_{2}} 2592:{\displaystyle \rho _{1}:G\to V_{1}} 1482:characters of a finite group form a 363:. A character of degree 1 is called 27:Concept in mathematical group theory 5270: 5149: 5047: 5023: 4999: 4928: 4900: 4746: 4495: 4447: 3529:{\textstyle G=\bigcup _{t\in T}HtK} 2933:, there is a unique class function 1508:on a 1-dimensional vector space by 652:, every such character value is an 582:If a character of the finite group 4851: 4797: 3740:induced from respective subgroups 2874:be a subgroup of the finite group 2491:It follows, using some results of 1643:with three elements and generator 1190: 1187: 1184: 1036: 1033: 1030: 830:Let ρ and σ be representations of 25: 5511:Character Theory of Finite Groups 4970:of an irreducible representation 2645:are linear representations, then 2549:are themselves a group under the 2481:{\displaystyle |G|\!\times \!|G|} 1504:, which is the trivial action of 508:a group homomorphism in general. 3437:, as well as Frobenius himself. 2336:Certain properties of the group 5621:Representation theory of groups 5278:{\displaystyle {\mathfrak {h}}} 5140: 5055:{\displaystyle {\mathfrak {h}}} 5031:{\displaystyle {\mathfrak {h}}} 5014:is determined by its values on 5007:{\displaystyle {\mathfrak {g}}} 4936:{\displaystyle {\mathfrak {h}}} 4908:{\displaystyle {\mathfrak {g}}} 4503:{\displaystyle {\mathfrak {g}}} 4455:{\displaystyle {\mathfrak {g}}} 3540:is a complex class function of 3027:for each irreducible character 2394:; this is a normal subgroup of 2327:Finding the order of the group. 1572:Here is the character table of 5536:. Cambridge University Press. 5132: 5126: 5092: 5086: 4874: 4861: 4843: 4837: 4678: 4672: 4656: 4653: 4647: 4631: 4597: 4592: 4586: 4575: 4563: 4557: 4510:, we can define the character 4421: 4418: 4412: 4406: 4394: 4388: 3253: 3247: 3101:, known as the representation 3089:Given a matrix representation 3069:, so is indeed a character of 2831: 2825: 2812: 2806: 2790: 2784: 2781: 2755: 2731: 2728: 2722: 2706: 2700: 2687: 2681: 2675: 2622: 2576: 2545:The linear representations of 2474: 2466: 2456: 2448: 2195: 2189: 2154: 2148: 2132: 2126: 1895: 1889: 1880: 1874: 1848: 1840: 1524: 1518: 1301: 1288: 1261: 1255: 1215: 1209: 1147: 1134: 1107: 1101: 1061: 1055: 737: 731: 723: 717: 708: 705: 699: 680: 476: 470: 454: 448: 288: 285: 279: 273: 261: 255: 1: 5428:Graduate Texts in Mathematics 4963:{\displaystyle \chi _{\rho }} 4943:. The value of the character 4781:{\displaystyle \chi _{\rho }} 4530:{\displaystyle \chi _{\rho }} 4341:{\displaystyle \chi _{\rho }} 4135:have the same restriction to 3108:, and written analogously as 2919:, using what is now known as 2844:. This group is connected to 2497:modular representation theory 1785:Schur orthogonality relations 568:they have the same character. 375:has characteristic zero, the 5231:{\displaystyle m_{\lambda }} 4711:in the associated Lie group 3398:is the trivial character of 2158: 1899: 1789:The space of complex-valued 996: 504:. However, the character is 147:generalized quaternion group 4614:The character will satisfy 4174:dimension of a vector space 571:If a representation is the 115:irreducible representations 5637: 5168:where the sum is over all 4246: 2895:denote its restriction to 2859: 2398:. Each normal subgroup of 2332:Character table properties 1782: 1536:{\displaystyle \rho (g)=1} 1471: 811:(and they even divide if 799:is equal to the number of 338:irreducible representation 29: 5568:10.1007/978-1-4684-9458-7 5436:10.1007/978-1-4612-0979-9 3682:is the class function of 3536:is a disjoint union, and 2909:Ferdinand Georg Frobenius 2359:(and thus whether or not 2295:denotes the order of the 2227: are conjugate  1394:, which is determined by 5251:{\displaystyle \lambda } 5184:{\displaystyle \lambda } 3051:is again a character of 2355:All normal subgroups of 5491:Hall, Brian C. (2015), 5238:is the multiplicity of 4919:with Cartan subalgebra 3379:is a class function of 3219:then, given an element 2943:with the property that 2371:is the set of elements 1779:Orthogonality relations 121:. Close to half of the 103:modular representations 41:, more specifically in 32:Character (mathematics) 5472:Gannon, Terry (2006). 5279: 5252: 5232: 5205: 5185: 5158: 5056: 5032: 5008: 4984: 4964: 4937: 4917:semisimple Lie algebra 4909: 4881: 4811: 4782: 4755: 4725: 4705: 4685: 4604: 4531: 4504: 4480: 4456: 4428: 4362: 4342: 4315: 4295: 4271: 4249:Weyl character formula 4084: 3667: 3530: 3366: 3210: 3018: 2838: 2738: 2639: 2593: 2482: 2258: 2066: 1908: 1630: 1563: 1562:{\displaystyle g\in G} 1537: 1501:trivial representation 1459: 1313: 1159: 1005: 950: 890: 747: 673:is irreducible, then 642:. In particular, when 600:Every character value 491: 295: 141:stating that a finite 18:Orthogonality relation 5509:Isaacs, I.M. (1994). 5316:to a normal subgroup 5280: 5253: 5233: 5206: 5204:{\displaystyle \rho } 5186: 5159: 5057: 5033: 5009: 4985: 4983:{\displaystyle \rho } 4965: 4938: 4910: 4882: 4812: 4783: 4756: 4726: 4706: 4686: 4605: 4532: 4505: 4481: 4479:{\displaystyle \rho } 4457: 4429: 4363: 4361:{\displaystyle \rho } 4343: 4316: 4296: 4294:{\displaystyle \rho } 4272: 4237:McKay–Thompson series 4085: 3668: 3531: 3404:permutation character 3367: 3211: 3019: 2922:Frobenius reciprocity 2866:Frobenius reciprocity 2839: 2739: 2640: 2594: 2483: 2259: 2067: 1909: 1772:third root of unity. 1631: 1564: 1538: 1472:Further information: 1460: 1314: 1160: 1006: 951: 891: 826:Arithmetic properties 748: 492: 296: 127:Feit–Thompson theorem 85:is determined (up to 65:of the corresponding 5265: 5261:The (restriction to 5242: 5215: 5195: 5175: 5073: 5042: 5018: 4994: 4974: 4947: 4923: 4895: 4824: 4792: 4765: 4735: 4715: 4695: 4618: 4544: 4514: 4490: 4470: 4442: 4375: 4352: 4325: 4305: 4285: 4261: 3763: 3551: 3492: 3441:Mackey decomposition 3234: 3159: 2950: 2878:. Given a character 2846:Dirichlet characters 2752: 2748:under the operation 2649: 2603: 2557: 2444: 2096: 1956: 1808: 1579: 1547: 1512: 1398: 1170: 1016: 961: 901: 841: 787:does not divide the 774:algebraically closed 677: 399: 242: 81:representation of a 73:initially developed 51:group representation 5300:Association schemes 4253:Algebraic character 4218:monstrous moonshine 4187:, its value at the 4168:"Twisted" dimension 3419:finite group theory 3353: 3306: 2514:: for example, the 2411:commutator subgroup 1370:alternating product 1358:conjugate transpose 586:is restricted to a 5552:Serre, Jean-Pierre 5363:Nicolas Bourbaki, 5331:, a group element 5275: 5248: 5228: 5201: 5181: 5154: 5107: 5052: 5028: 5004: 4980: 4960: 4933: 4905: 4877: 4807: 4778: 4751: 4721: 4701: 4681: 4600: 4527: 4500: 4476: 4452: 4424: 4358: 4338: 4311: 4291: 4267: 4080: 4078: 3980: 3876: 3663: 3597: 3526: 3516: 3457:of a finite group 3449:in the context of 3410:(on the cosets of 3362: 3336: 3314: 3289: 3206: 3061:is a non-negative 3014: 2903:be a character of 2834: 2734: 2635: 2589: 2478: 2303:. Note that since 2254: 2249: 2245: 2229: 2213: 2115: 2062: 2057: 2041: 2013: 1904: 1870: 1793:of a finite group 1626: 1559: 1533: 1455: 1309: 1231: 1202: 1155: 1077: 1048: 1001: 946: 886: 743: 577:subrepresentations 487: 291: 171:finite-dimensional 131:Burnside's theorem 5577:978-0-387-90190-9 5543:978-0-521-00392-6 5520:978-0-486-68014-9 5483:978-0-521-83531-2 5445:978-0-387-97495-8 5404:Proposition 10.12 5324:Frobenius formula 5098: 4891:Suppose now that 4724:{\displaystyle G} 4704:{\displaystyle g} 4314:{\displaystyle G} 4270:{\displaystyle G} 4097:is a full set of 3965: 3861: 3582: 3501: 3275: 3269: 3259: 3073:. It is known as 2862:Induced character 2244: 2228: 2212: 2161: 2099: 2040: 2012: 1947:orthonormal basis 1932:complex conjugate 1902: 1855: 1853: 1762: 1761: 1440: 1230: 1076: 999: 801:conjugacy classes 755:algebraic integer 741: 654:algebraic integer 379:of the character 344:of the character 16:(Redirected from 5628: 5589: 5561: 5547: 5524: 5505: 5487: 5465: 5405: 5399: 5393: 5386: 5377: 5374: 5368: 5361: 5319: 5315: 5308:, introduced by 5284: 5282: 5281: 5276: 5274: 5273: 5257: 5255: 5254: 5249: 5237: 5235: 5234: 5229: 5227: 5226: 5210: 5208: 5207: 5202: 5190: 5188: 5187: 5182: 5163: 5161: 5160: 5155: 5153: 5152: 5136: 5135: 5117: 5116: 5106: 5085: 5084: 5061: 5059: 5058: 5053: 5051: 5050: 5037: 5035: 5034: 5029: 5027: 5026: 5013: 5011: 5010: 5005: 5003: 5002: 4989: 4987: 4986: 4981: 4969: 4967: 4966: 4961: 4959: 4958: 4942: 4940: 4939: 4934: 4932: 4931: 4914: 4912: 4911: 4906: 4904: 4903: 4886: 4884: 4883: 4878: 4873: 4872: 4860: 4859: 4854: 4836: 4835: 4816: 4814: 4813: 4808: 4806: 4805: 4800: 4787: 4785: 4784: 4779: 4777: 4776: 4760: 4758: 4757: 4752: 4750: 4749: 4730: 4728: 4727: 4722: 4710: 4708: 4707: 4702: 4690: 4688: 4687: 4682: 4671: 4670: 4643: 4642: 4630: 4629: 4609: 4607: 4606: 4601: 4596: 4595: 4556: 4555: 4536: 4534: 4533: 4528: 4526: 4525: 4509: 4507: 4506: 4501: 4499: 4498: 4485: 4483: 4482: 4477: 4461: 4459: 4458: 4453: 4451: 4450: 4433: 4431: 4430: 4425: 4387: 4386: 4367: 4365: 4364: 4359: 4347: 4345: 4344: 4339: 4337: 4336: 4321:, the character 4320: 4318: 4317: 4312: 4300: 4298: 4297: 4292: 4276: 4274: 4273: 4268: 4229:graded dimension 4224: 4212: 4186: 4163: 4155: 4151: 4147: 4134: 4130: 4124: 4120: 4116: 4112: 4108: 4096: 4089: 4087: 4086: 4081: 4079: 4072: 4068: 4067: 4066: 4053: 4052: 4032: 4031: 4018: 4017: 4004: 4000: 3999: 3979: 3958: 3954: 3950: 3943: 3942: 3937: 3933: 3932: 3919: 3918: 3905: 3901: 3900: 3875: 3854: 3850: 3846: 3839: 3838: 3833: 3829: 3828: 3802: 3798: 3797: 3796: 3784: 3783: 3755: 3751: 3747: 3743: 3739: 3735: 3720: 3716: 3712: 3690: 3681: 3672: 3670: 3669: 3664: 3659: 3658: 3653: 3649: 3648: 3635: 3634: 3621: 3617: 3616: 3596: 3578: 3577: 3572: 3568: 3567: 3543: 3539: 3535: 3533: 3532: 3527: 3515: 3485:-double cosets. 3484: 3472: 3468: 3464: 3460: 3456: 3413: 3409: 3401: 3397: 3393: 3389: 3382: 3378: 3371: 3369: 3368: 3363: 3358: 3354: 3352: 3344: 3332: 3331: 3313: 3305: 3297: 3285: 3284: 3273: 3267: 3246: 3245: 3226: 3222: 3215: 3213: 3212: 3207: 3202: 3201: 3180: 3179: 3151: 3139: 3136:. If one writes 3135: 3131: 3127: 3123: 3119: 3113: 3107: 3100: 3096: 3092: 3085: 3079: 3075:the character of 3072: 3068: 3060: 3054: 3050: 3047:to the subgroup 3046: 3042: 3038: 3034: 3030: 3023: 3021: 3020: 3015: 3013: 3012: 3003: 3002: 2981: 2980: 2965: 2964: 2942: 2938: 2932: 2928: 2918: 2914: 2906: 2902: 2898: 2894: 2885: 2881: 2877: 2873: 2850:Fourier analysis 2843: 2841: 2840: 2835: 2824: 2823: 2805: 2804: 2780: 2779: 2767: 2766: 2743: 2741: 2740: 2735: 2721: 2720: 2699: 2698: 2674: 2673: 2661: 2660: 2644: 2642: 2641: 2636: 2634: 2633: 2615: 2614: 2598: 2596: 2595: 2590: 2588: 2587: 2569: 2568: 2548: 2537: 2528: 2520: 2516:quaternion group 2487: 2485: 2484: 2479: 2477: 2469: 2459: 2451: 2439: 2431: 2427: 2420: 2416: 2405: 2401: 2397: 2393: 2378: 2374: 2370: 2362: 2358: 2347: 2339: 2310: 2306: 2302: 2294: 2279: 2275: 2263: 2261: 2260: 2255: 2253: 2252: 2246: 2243: otherwise. 2242: 2230: 2226: 2214: 2210: 2202: 2198: 2188: 2187: 2162: 2157: 2147: 2146: 2136: 2125: 2124: 2114: 2113: 2112: 2088: 2084: 2071: 2069: 2068: 2063: 2061: 2060: 2042: 2038: 2014: 2010: 1991: 1987: 1986: 1985: 1973: 1972: 1944: 1929: 1928: 1913: 1911: 1910: 1905: 1903: 1898: 1884: 1869: 1854: 1852: 1851: 1843: 1834: 1829: 1825: 1796: 1767: 1758: 1753: 1746: 1741: 1729: 1722: 1717: 1712: 1700: 1695: 1690: 1685: 1676: 1667: 1658: 1650: 1635: 1633: 1632: 1627: 1613: 1612: 1591: 1590: 1568: 1566: 1565: 1560: 1542: 1540: 1539: 1534: 1507: 1497: 1493: 1489: 1478:The irreducible 1468:Character tables 1464: 1462: 1461: 1456: 1448: 1447: 1442: 1441: 1438: 1431: 1427: 1392:symmetric square 1389: 1385: 1367: 1363: 1355: 1345: 1331: 1318: 1316: 1315: 1310: 1308: 1304: 1300: 1299: 1287: 1286: 1274: 1273: 1268: 1264: 1254: 1253: 1232: 1223: 1208: 1207: 1203: 1201: 1200: 1199: 1198: 1193: 1164: 1162: 1161: 1156: 1154: 1150: 1146: 1145: 1133: 1132: 1120: 1119: 1114: 1110: 1100: 1099: 1078: 1069: 1054: 1053: 1049: 1047: 1046: 1045: 1044: 1039: 1010: 1008: 1007: 1002: 1000: 995: 994: 985: 980: 979: 978: 977: 955: 953: 952: 947: 945: 944: 932: 931: 919: 918: 895: 893: 892: 887: 885: 884: 872: 871: 859: 858: 833: 820: 810: 806: 798: 794: 786: 771: 764: 760: 752: 750: 749: 744: 742: 740: 726: 712: 698: 697: 672: 668: 651: 641: 633: 629: 625: 617: 614: 610: 596: 592: 585: 563: 550: 540: 532: 528: 503: 496: 494: 493: 488: 483: 479: 469: 468: 447: 446: 417: 416: 387: 374: 370: 362: 355: 347: 335: 323: 307: 300: 298: 297: 292: 254: 253: 234: 218:is the function 217: 209: 205: 197: 182: 168: 154: 21: 5636: 5635: 5631: 5630: 5629: 5627: 5626: 5625: 5611: 5610: 5597: 5592: 5578: 5550: 5544: 5530:Liebeck, Martin 5528:James, Gordon; 5527: 5521: 5508: 5503: 5490: 5484: 5471: 5446: 5416:Fulton, William 5414: 5409: 5408: 5400: 5396: 5387: 5380: 5375: 5371: 5362: 5358: 5353: 5317: 5313: 5306:Clifford theory 5291: 5263: 5262: 5240: 5239: 5218: 5213: 5212: 5193: 5192: 5173: 5172: 5118: 5108: 5076: 5071: 5070: 5040: 5039: 5016: 5015: 4992: 4991: 4972: 4971: 4950: 4945: 4944: 4921: 4920: 4893: 4892: 4864: 4849: 4827: 4822: 4821: 4795: 4790: 4789: 4768: 4763: 4762: 4733: 4732: 4713: 4712: 4693: 4692: 4662: 4634: 4621: 4616: 4615: 4578: 4547: 4542: 4541: 4517: 4512: 4511: 4488: 4487: 4468: 4467: 4440: 4439: 4378: 4373: 4372: 4350: 4349: 4328: 4323: 4322: 4303: 4302: 4283: 4282: 4259: 4258: 4255: 4245: 4222: 4205: 4192: 4177: 4170: 4157: 4153: 4149: 4136: 4132: 4126: 4122: 4118: 4114: 4110: 4098: 4094: 4077: 4076: 4041: 4036: 4006: 3991: 3987: 3986: 3985: 3981: 3956: 3955: 3907: 3892: 3888: 3887: 3883: 3882: 3881: 3877: 3852: 3851: 3820: 3816: 3815: 3814: 3810: 3803: 3788: 3775: 3774: 3770: 3761: 3760: 3753: 3749: 3745: 3741: 3737: 3733: 3718: 3714: 3692: 3683: 3677: 3623: 3608: 3604: 3603: 3599: 3598: 3559: 3555: 3554: 3549: 3548: 3541: 3537: 3490: 3489: 3474: 3470: 3466: 3462: 3458: 3454: 3443: 3411: 3407: 3399: 3395: 3391: 3387: 3380: 3376: 3323: 3322: 3318: 3276: 3237: 3232: 3231: 3224: 3220: 3193: 3171: 3157: 3156: 3149: 3137: 3133: 3129: 3125: 3121: 3115: 3109: 3105: 3098: 3094: 3090: 3083: 3077: 3070: 3066: 3056: 3052: 3048: 3044: 3040: 3036: 3032: 3028: 3004: 2994: 2972: 2956: 2948: 2947: 2940: 2934: 2930: 2926: 2916: 2912: 2904: 2900: 2896: 2892: 2887: 2883: 2879: 2875: 2871: 2868: 2860:Main articles: 2858: 2815: 2796: 2771: 2758: 2750: 2749: 2746:character group 2712: 2690: 2665: 2652: 2647: 2646: 2625: 2606: 2601: 2600: 2579: 2560: 2555: 2554: 2546: 2536: 2530: 2526: 2518: 2442: 2441: 2437: 2429: 2425: 2418: 2414: 2403: 2399: 2395: 2380: 2376: 2372: 2368: 2367:of a character 2360: 2356: 2350:absolute values 2345: 2337: 2334: 2308: 2304: 2300: 2287: 2281: 2280:and the symbol 2277: 2273: 2268: 2248: 2247: 2238: 2232: 2231: 2206: 2179: 2178: 2174: 2167: 2138: 2137: 2116: 2104: 2094: 2093: 2086: 2076: 2056: 2055: 2034: 2028: 2027: 2006: 1996: 1977: 1964: 1963: 1959: 1954: 1953: 1935: 1919: 1918: 1885: 1838: 1815: 1811: 1806: 1805: 1794: 1791:class functions 1787: 1781: 1765: 1756: 1749: 1744: 1740: 1734: 1725: 1720: 1715: 1711: 1705: 1698: 1693: 1688: 1681: 1670: 1661: 1656: 1604: 1582: 1577: 1576: 1545: 1544: 1510: 1509: 1505: 1495: 1491: 1487: 1484:character table 1476: 1474:Character table 1470: 1435: 1417: 1413: 1396: 1395: 1387: 1372: 1365: 1361: 1351: 1337: 1323: 1291: 1278: 1245: 1244: 1240: 1239: 1238: 1234: 1182: 1173: 1168: 1167: 1137: 1124: 1091: 1090: 1086: 1085: 1084: 1080: 1028: 1019: 1014: 1013: 986: 969: 964: 959: 958: 936: 923: 904: 899: 898: 876: 863: 844: 839: 838: 831: 828: 812: 808: 804: 796: 792: 777: 769: 762: 758: 727: 713: 689: 675: 674: 670: 660: 643: 639: 631: 627: 623: 615: 612: 601: 594: 590: 583: 561: 542: 538: 530: 526: 523:conjugacy class 519:class functions 517:Characters are 514: 501: 460: 438: 425: 421: 408: 397: 396: 390:normal subgroup 385: 380: 372: 368: 357: 353: 345: 333: 321: 316: 305: 245: 240: 239: 224: 219: 215: 207: 203: 184: 180: 166: 163: 152: 111: 71:Georg Frobenius 35: 28: 23: 22: 15: 12: 11: 5: 5634: 5632: 5624: 5623: 5613: 5612: 5609: 5608: 5596: 5595:External links 5593: 5591: 5590: 5576: 5548: 5542: 5525: 5519: 5506: 5502:978-3319134666 5501: 5488: 5482: 5469: 5444: 5410: 5407: 5406: 5394: 5378: 5369: 5355: 5354: 5352: 5349: 5348: 5347: 5326: 5321: 5310:A. H. Clifford 5303: 5297: 5290: 5287: 5272: 5247: 5225: 5221: 5200: 5180: 5166: 5165: 5151: 5146: 5143: 5139: 5134: 5131: 5128: 5125: 5121: 5115: 5111: 5105: 5101: 5097: 5094: 5091: 5088: 5083: 5079: 5066:, as follows: 5049: 5025: 5001: 4979: 4957: 4953: 4930: 4902: 4889: 4888: 4876: 4871: 4867: 4863: 4858: 4853: 4848: 4845: 4842: 4839: 4834: 4830: 4804: 4799: 4775: 4771: 4748: 4743: 4740: 4720: 4700: 4680: 4677: 4674: 4669: 4665: 4661: 4658: 4655: 4652: 4649: 4646: 4641: 4637: 4633: 4628: 4624: 4612: 4611: 4599: 4594: 4591: 4588: 4585: 4581: 4577: 4574: 4571: 4568: 4565: 4562: 4559: 4554: 4550: 4524: 4520: 4497: 4475: 4449: 4438:Meanwhile, if 4436: 4435: 4423: 4420: 4417: 4414: 4411: 4408: 4405: 4402: 4399: 4396: 4393: 4390: 4385: 4381: 4357: 4335: 4331: 4310: 4290: 4266: 4244: 4241: 4203: 4169: 4166: 4091: 4090: 4075: 4071: 4065: 4062: 4059: 4056: 4051: 4048: 4044: 4039: 4035: 4030: 4027: 4024: 4021: 4016: 4013: 4009: 4003: 3998: 3994: 3990: 3984: 3978: 3975: 3972: 3968: 3964: 3961: 3959: 3957: 3953: 3949: 3946: 3941: 3936: 3931: 3928: 3925: 3922: 3917: 3914: 3910: 3904: 3899: 3895: 3891: 3886: 3880: 3874: 3871: 3868: 3864: 3860: 3857: 3855: 3853: 3849: 3845: 3842: 3837: 3832: 3827: 3823: 3819: 3813: 3809: 3806: 3804: 3801: 3795: 3791: 3787: 3782: 3778: 3773: 3769: 3768: 3674: 3673: 3662: 3657: 3652: 3647: 3644: 3641: 3638: 3633: 3630: 3626: 3620: 3615: 3611: 3607: 3602: 3595: 3592: 3589: 3585: 3581: 3576: 3571: 3566: 3562: 3558: 3525: 3522: 3519: 3514: 3511: 3508: 3504: 3500: 3497: 3442: 3439: 3427:Richard Brauer 3373: 3372: 3361: 3357: 3351: 3348: 3343: 3339: 3335: 3330: 3326: 3321: 3317: 3312: 3309: 3304: 3301: 3296: 3292: 3288: 3283: 3279: 3272: 3266: 3262: 3258: 3255: 3252: 3249: 3244: 3240: 3217: 3216: 3205: 3200: 3196: 3192: 3189: 3186: 3183: 3178: 3174: 3170: 3167: 3164: 3142:disjoint union 3025: 3024: 3011: 3007: 3001: 2997: 2993: 2990: 2987: 2984: 2979: 2975: 2971: 2968: 2963: 2959: 2955: 2890: 2857: 2854: 2833: 2830: 2827: 2822: 2818: 2814: 2811: 2808: 2803: 2799: 2795: 2792: 2789: 2786: 2783: 2778: 2774: 2770: 2765: 2761: 2757: 2733: 2730: 2727: 2724: 2719: 2715: 2711: 2708: 2705: 2702: 2697: 2693: 2689: 2686: 2683: 2680: 2677: 2672: 2668: 2664: 2659: 2655: 2632: 2628: 2624: 2621: 2618: 2613: 2609: 2586: 2582: 2578: 2575: 2572: 2567: 2563: 2551:tensor product 2534: 2523:dihedral group 2505: 2504: 2493:Richard Brauer 2489: 2476: 2472: 2468: 2463: 2458: 2454: 2450: 2422: 2407: 2353: 2333: 2330: 2329: 2328: 2325: 2322: 2319: 2285: 2271: 2265: 2264: 2251: 2239: 2237: 2234: 2233: 2223: 2220: 2217: 2211: if  2207: 2205: 2201: 2197: 2194: 2191: 2186: 2182: 2177: 2173: 2172: 2170: 2165: 2160: 2156: 2153: 2150: 2145: 2141: 2134: 2131: 2128: 2123: 2119: 2111: 2107: 2102: 2073: 2072: 2059: 2054: 2051: 2048: 2045: 2039: if  2035: 2033: 2030: 2029: 2026: 2023: 2020: 2017: 2011: if  2007: 2005: 2002: 2001: 1999: 1994: 1990: 1984: 1980: 1976: 1971: 1967: 1962: 1915: 1914: 1901: 1897: 1894: 1891: 1888: 1882: 1879: 1876: 1873: 1868: 1865: 1862: 1858: 1850: 1846: 1842: 1837: 1832: 1828: 1824: 1821: 1818: 1814: 1797:has a natural 1783:Main article: 1780: 1777: 1760: 1759: 1754: 1747: 1742: 1738: 1731: 1730: 1723: 1718: 1713: 1709: 1702: 1701: 1696: 1691: 1686: 1678: 1677: 1668: 1659: 1654: 1637: 1636: 1625: 1622: 1619: 1616: 1611: 1607: 1603: 1600: 1597: 1594: 1589: 1585: 1558: 1555: 1552: 1532: 1529: 1526: 1523: 1520: 1517: 1469: 1466: 1454: 1451: 1446: 1434: 1430: 1426: 1423: 1420: 1416: 1412: 1409: 1406: 1403: 1348:tensor product 1320: 1319: 1307: 1303: 1298: 1294: 1290: 1285: 1281: 1277: 1272: 1267: 1263: 1260: 1257: 1252: 1248: 1243: 1237: 1229: 1226: 1220: 1217: 1214: 1211: 1206: 1197: 1192: 1189: 1186: 1176: 1165: 1153: 1149: 1144: 1140: 1136: 1131: 1127: 1123: 1118: 1113: 1109: 1106: 1103: 1098: 1094: 1089: 1083: 1075: 1072: 1066: 1063: 1060: 1057: 1052: 1043: 1038: 1035: 1032: 1022: 1011: 998: 993: 989: 983: 976: 972: 967: 956: 943: 939: 935: 930: 926: 922: 917: 914: 911: 907: 896: 883: 879: 875: 870: 866: 862: 857: 854: 851: 847: 827: 824: 823: 822: 766: 739: 736: 733: 730: 725: 722: 719: 716: 710: 707: 704: 701: 696: 692: 688: 685: 682: 657: 620:roots of unity 598: 580: 569: 566:if and only if 559:characteristic 552: 513: 510: 498: 497: 486: 482: 478: 475: 472: 467: 463: 459: 456: 453: 450: 445: 441: 437: 434: 431: 428: 424: 420: 415: 411: 407: 404: 383: 371:is finite and 319: 302: 301: 290: 287: 284: 281: 278: 275: 272: 269: 266: 263: 260: 257: 252: 248: 222: 200:representation 162: 159: 145:cannot have a 135:Richard Brauer 113:Characters of 110: 107: 99:Richard Brauer 95:characteristic 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 5633: 5622: 5619: 5618: 5616: 5606: 5602: 5599: 5598: 5594: 5587: 5583: 5579: 5573: 5569: 5565: 5560: 5559: 5553: 5549: 5545: 5539: 5535: 5531: 5526: 5522: 5516: 5512: 5507: 5504: 5498: 5494: 5489: 5485: 5479: 5475: 5470: 5468: 5463: 5459: 5455: 5451: 5447: 5441: 5437: 5433: 5429: 5425: 5421: 5417: 5413:Lecture 2 of 5412: 5411: 5403: 5398: 5395: 5391: 5385: 5383: 5379: 5373: 5370: 5366: 5360: 5357: 5350: 5346: 5342: 5338: 5334: 5330: 5327: 5325: 5322: 5311: 5307: 5304: 5301: 5298: 5296: 5293: 5292: 5288: 5286: 5259: 5245: 5223: 5219: 5198: 5178: 5171: 5144: 5141: 5137: 5129: 5123: 5119: 5113: 5109: 5103: 5099: 5095: 5089: 5081: 5077: 5069: 5068: 5067: 5065: 5064:weight spaces 4977: 4955: 4951: 4918: 4915:is a complex 4869: 4865: 4856: 4846: 4840: 4832: 4828: 4820: 4819: 4818: 4802: 4773: 4769: 4741: 4738: 4718: 4698: 4675: 4667: 4663: 4659: 4650: 4644: 4639: 4635: 4626: 4622: 4589: 4583: 4579: 4572: 4569: 4566: 4560: 4552: 4548: 4540: 4539: 4538: 4522: 4518: 4473: 4465: 4415: 4409: 4403: 4400: 4397: 4391: 4383: 4379: 4371: 4370: 4369: 4355: 4333: 4329: 4308: 4288: 4280: 4264: 4254: 4250: 4242: 4240: 4238: 4234: 4233:Monster group 4230: 4226: 4219: 4214: 4210: 4206: 4199: 4195: 4190: 4184: 4180: 4175: 4167: 4165: 4161: 4146: 4142: 4139: 4129: 4106: 4102: 4073: 4069: 4063: 4060: 4057: 4054: 4049: 4046: 4042: 4037: 4033: 4028: 4025: 4022: 4019: 4014: 4011: 4007: 4001: 3996: 3992: 3988: 3982: 3976: 3973: 3970: 3966: 3962: 3960: 3951: 3947: 3944: 3939: 3934: 3929: 3926: 3923: 3920: 3915: 3912: 3908: 3902: 3897: 3893: 3889: 3884: 3878: 3872: 3869: 3866: 3862: 3858: 3856: 3847: 3843: 3840: 3835: 3830: 3825: 3821: 3817: 3811: 3807: 3805: 3799: 3793: 3789: 3785: 3780: 3776: 3771: 3759: 3758: 3757: 3730: 3728: 3724: 3710: 3706: 3702: 3699: 3695: 3689: 3686: 3680: 3660: 3655: 3650: 3645: 3642: 3639: 3636: 3631: 3628: 3624: 3618: 3613: 3609: 3605: 3600: 3593: 3590: 3587: 3583: 3579: 3574: 3569: 3564: 3560: 3556: 3547: 3546: 3545: 3523: 3520: 3517: 3512: 3509: 3506: 3502: 3498: 3495: 3486: 3482: 3478: 3452: 3448: 3447:George Mackey 3440: 3438: 3436: 3435:Michio Suzuki 3432: 3428: 3424: 3420: 3415: 3405: 3384: 3359: 3355: 3349: 3346: 3341: 3337: 3333: 3328: 3324: 3319: 3315: 3310: 3307: 3302: 3299: 3294: 3290: 3286: 3281: 3277: 3270: 3264: 3260: 3256: 3250: 3242: 3238: 3230: 3229: 3228: 3203: 3198: 3194: 3190: 3187: 3184: 3181: 3176: 3172: 3168: 3165: 3162: 3155: 3154: 3153: 3147: 3143: 3118: 3112: 3104: 3087: 3082: 3076: 3064: 3059: 3009: 2999: 2995: 2991: 2988: 2982: 2977: 2969: 2966: 2961: 2957: 2946: 2945: 2944: 2937: 2924: 2923: 2910: 2893: 2867: 2863: 2855: 2853: 2851: 2847: 2828: 2820: 2816: 2809: 2801: 2797: 2793: 2787: 2776: 2772: 2768: 2763: 2759: 2747: 2725: 2717: 2713: 2709: 2703: 2695: 2691: 2684: 2678: 2670: 2666: 2662: 2657: 2653: 2630: 2626: 2619: 2616: 2611: 2607: 2584: 2580: 2573: 2570: 2565: 2561: 2552: 2543: 2541: 2533: 2524: 2517: 2513: 2510: 2502: 2501:Graham Higman 2498: 2494: 2490: 2470: 2461: 2452: 2435: 2423: 2412: 2408: 2391: 2387: 2383: 2366: 2354: 2351: 2344:The order of 2343: 2342: 2341: 2331: 2326: 2323: 2320: 2317: 2316: 2315: 2312: 2298: 2292: 2288: 2274: 2235: 2221: 2218: 2215: 2203: 2199: 2192: 2184: 2180: 2175: 2168: 2163: 2151: 2143: 2139: 2129: 2121: 2117: 2109: 2105: 2100: 2092: 2091: 2090: 2083: 2079: 2052: 2049: 2046: 2043: 2031: 2024: 2021: 2018: 2015: 2003: 1997: 1992: 1988: 1982: 1978: 1974: 1969: 1965: 1960: 1952: 1951: 1950: 1948: 1942: 1938: 1933: 1926: 1922: 1892: 1886: 1877: 1871: 1866: 1863: 1860: 1856: 1844: 1835: 1830: 1826: 1822: 1819: 1816: 1812: 1804: 1803: 1802: 1800: 1799:inner product 1792: 1786: 1778: 1776: 1773: 1771: 1755: 1752: 1748: 1743: 1737: 1733: 1732: 1728: 1724: 1719: 1714: 1708: 1704: 1703: 1697: 1692: 1687: 1684: 1680: 1679: 1674: 1669: 1665: 1660: 1655: 1652: 1651: 1648: 1646: 1642: 1623: 1617: 1614: 1609: 1605: 1601: 1598: 1592: 1587: 1583: 1575: 1574: 1573: 1570: 1556: 1553: 1550: 1530: 1527: 1521: 1515: 1503: 1502: 1485: 1481: 1475: 1467: 1465: 1452: 1449: 1444: 1432: 1428: 1424: 1421: 1418: 1414: 1410: 1407: 1404: 1401: 1393: 1384: 1380: 1376: 1371: 1359: 1354: 1349: 1344: 1340: 1335: 1330: 1326: 1305: 1296: 1292: 1283: 1279: 1275: 1270: 1265: 1258: 1250: 1246: 1241: 1235: 1227: 1224: 1218: 1212: 1204: 1195: 1174: 1166: 1151: 1142: 1138: 1129: 1125: 1121: 1116: 1111: 1104: 1096: 1092: 1087: 1081: 1073: 1070: 1064: 1058: 1050: 1041: 1020: 1012: 991: 987: 981: 974: 970: 965: 957: 941: 937: 933: 928: 924: 920: 915: 912: 909: 905: 897: 881: 877: 873: 868: 864: 860: 855: 852: 849: 845: 837: 836: 835: 825: 819: 815: 802: 790: 784: 780: 775: 767: 756: 734: 728: 720: 714: 702: 694: 690: 686: 683: 667: 663: 658: 655: 650: 646: 637: 621: 608: 604: 599: 589: 581: 578: 574: 570: 567: 560: 556: 553: 549: 545: 536: 529:into a field 524: 520: 516: 515: 511: 509: 507: 484: 480: 473: 465: 461: 457: 451: 443: 439: 435: 432: 429: 426: 422: 418: 413: 409: 405: 402: 395: 394: 393: 391: 386: 378: 366: 360: 351: 343: 339: 331: 327: 322: 313: 311: 282: 276: 270: 267: 264: 258: 250: 246: 238: 237: 236: 233: 229: 225: 213: 201: 195: 191: 187: 179: 175: 172: 160: 158: 156: 148: 144: 140: 139:Michio Suzuki 136: 132: 128: 124: 120: 116: 108: 106: 104: 100: 96: 92: 88: 84: 80: 76: 72: 68: 64: 60: 56: 52: 48: 44: 40: 33: 19: 5557: 5533: 5510: 5492: 5473: 5423: 5397: 5372: 5364: 5359: 5344: 5340: 5336: 5332: 5329:Real element 5260: 5167: 4890: 4613: 4437: 4256: 4215: 4208: 4201: 4197: 4193: 4182: 4178: 4171: 4159: 4144: 4140: 4137: 4127: 4104: 4100: 4092: 3731: 3708: 3704: 3700: 3697: 3693: 3687: 3684: 3678: 3675: 3487: 3480: 3476: 3444: 3416: 3403: 3385: 3374: 3218: 3116: 3110: 3103:induced from 3088: 3081:induced from 3080: 3074: 3057: 3026: 2935: 2920: 2888: 2869: 2544: 2531: 2506: 2389: 2385: 2381: 2335: 2313: 2290: 2283: 2269: 2266: 2081: 2077: 2074: 1940: 1936: 1924: 1920: 1916: 1788: 1774: 1763: 1750: 1735: 1726: 1706: 1682: 1672: 1663: 1644: 1641:cyclic group 1638: 1571: 1499: 1483: 1477: 1382: 1378: 1374: 1356:denotes the 1352: 1342: 1338: 1328: 1324: 1321: 829: 817: 813: 782: 665: 661: 648: 644: 611:is a sum of 606: 602: 547: 543: 505: 499: 381: 376: 364: 358: 341: 329: 325: 317: 315:A character 314: 303: 231: 227: 220: 211: 193: 189: 185: 174:vector space 164: 143:simple group 112: 109:Applications 93:of positive 83:finite group 46: 43:group theory 36: 5420:Harris, Joe 5390:Gannon 2006 5376:Serre, §2.5 4464:Lie algebra 3727:topological 3691:defined by 3431:Walter Feit 3227:, we have: 2512:isomorphism 2297:centralizer 326:irreducible 202:of a group 161:Definitions 87:isomorphism 39:mathematics 5605:PlanetMath 5351:References 5335:such that 5211:and where 4247:See also: 4225:-invariant 4200:(1)) = Tr( 3729:contexts. 3451:Lie groups 3423:Emil Artin 2540:E. C. Dade 2529:elements, 2379:for which 1334:direct sum 573:direct sum 555:Isomorphic 512:Properties 324:is called 5601:Character 5462:246650103 5402:Hall 2015 5246:λ 5224:λ 5199:ρ 5179:λ 5145:∈ 5124:λ 5114:λ 5104:λ 5100:∑ 5082:ρ 5078:χ 4978:ρ 4956:ρ 4952:χ 4857:ρ 4833:ρ 4829:χ 4803:ρ 4774:ρ 4770:χ 4742:∈ 4668:ρ 4664:χ 4645:⁡ 4627:ρ 4623:χ 4584:ρ 4573:⁡ 4553:ρ 4549:χ 4523:ρ 4519:χ 4474:ρ 4410:ρ 4404:⁡ 4384:ρ 4380:χ 4356:ρ 4334:ρ 4330:χ 4289:ρ 4279:Lie group 4196:(1) = Tr( 4061:∩ 4047:− 4038:ψ 4026:∩ 4012:− 3993:θ 3974:∈ 3967:∑ 3948:ψ 3927:∩ 3913:− 3894:θ 3870:∈ 3863:∑ 3844:ψ 3822:θ 3790:ψ 3777:θ 3643:∩ 3629:− 3610:θ 3591:∈ 3584:∑ 3561:θ 3510:∈ 3503:⋃ 3347:− 3316:θ 3308:∈ 3300:− 3261:∑ 3239:θ 3188:∪ 3185:… 3182:∪ 3144:of right 3006:⟩ 2996:χ 2989:θ 2986:⟨ 2974:⟩ 2970:χ 2958:θ 2954:⟨ 2817:χ 2798:χ 2773:χ 2769:∗ 2760:χ 2714:ρ 2710:⊗ 2692:ρ 2667:ρ 2663:⊗ 2654:ρ 2623:→ 2608:ρ 2577:→ 2562:ρ 2462:× 2159:¯ 2140:χ 2118:χ 2106:χ 2101:∑ 2019:≠ 1979:χ 1966:χ 1900:¯ 1887:β 1872:α 1864:∈ 1857:∑ 1823:β 1817:α 1770:primitive 1621:⟩ 1602:∣ 1596:⟨ 1554:∈ 1516:ρ 1450:ρ 1433:⊕ 1425:ρ 1422:∧ 1419:ρ 1408:ρ 1405:⊗ 1402:ρ 1284:ρ 1280:χ 1251:ρ 1247:χ 1205:ρ 1175:χ 1130:ρ 1126:χ 1122:− 1097:ρ 1093:χ 1051:ρ 1021:χ 997:¯ 992:ρ 988:χ 975:∗ 971:ρ 966:χ 942:σ 938:χ 934:⋅ 929:ρ 925:χ 916:σ 913:⊗ 910:ρ 906:χ 882:σ 878:χ 869:ρ 865:χ 856:σ 853:⊕ 850:ρ 846:χ 729:χ 715:χ 466:ρ 462:χ 444:ρ 440:χ 436:∣ 430:∈ 414:ρ 410:χ 406:⁡ 350:dimension 277:ρ 271:⁡ 251:ρ 247:χ 235:given by 212:character 155:-subgroup 47:character 5615:Category 5554:(1977). 5532:(2001). 5422:(1991). 5289:See also 4731:and all 4691:for all 4207:) = dim( 4189:identity 4070:⟩ 3983:⟨ 3952:⟩ 3879:⟨ 3848:⟩ 3812:⟨ 3800:⟩ 3772:⟨ 3713:for all 3375:Because 2521:and the 1989:⟩ 1961:⟨ 1827:⟩ 1813:⟨ 1543:for all 757:for all 622:, where 588:subgroup 226: : 188: : 183:and let 55:function 5586:0450380 5454:1153249 5365:Algèbre 5170:weights 4227:is the 4093:(where 3063:integer 2434:abelian 2293:)| 1930:is the 1653:  1480:complex 1390:is the 1368:is the 1346:is the 1332:is the 634:is the 537:of the 533:form a 388:is the 367:. When 348:is the 340:. The 308:is the 176:over a 149:as its 125:of the 79:complex 57:on the 5584:  5574:  5540:  5517:  5499:  5480:  5467:online 5460:  5452:  5442:  4220:: the 4162:| 4158:| 3676:where 3274:  3268:  3152:, say 3146:cosets 2899:. Let 2886:, let 2365:kernel 2282:| 1917:where 1764:where 1364:, and 1322:where 753:is an 377:kernel 365:linear 342:degree 336:is an 330:simple 304:where 210:. The 151:Sylow 67:matrix 45:, the 4462:is a 4277:is a 4148:. If 3473:into 3140:as a 2915:from 2509:up to 2495:from 1768:is a 789:order 636:order 535:basis 310:trace 198:be a 192:→ GL( 178:field 169:be a 123:proof 91:field 63:trace 59:group 53:is a 49:of a 5572:ISBN 5538:ISBN 5515:ISBN 5497:ISBN 5478:ISBN 5458:OCLC 5440:ISBN 4466:and 4281:and 4251:and 4152:and 4131:and 4113:and 3752:and 3744:and 3736:and 3723:ring 3703:) = 3433:and 2864:and 2848:and 2599:and 2409:The 2388:) = 2307:and 2075:For 1639:the 1386:and 779:char 776:and 669:and 630:and 618:-th 165:Let 137:and 5603:at 5564:doi 5432:doi 5191:of 4990:of 4537:by 4348:of 4257:If 4121:or 3717:in 3488:If 3465:of 3414:). 3406:of 3390:in 3223:of 3148:of 3093:of 3031:of 2939:of 2882:of 2525:of 2440:is 2432:is 2424:If 2413:of 2392:(1) 2375:in 2299:of 2276:of 2085:in 1934:of 1657:(1) 1439:Sym 1388:Sym 1373:Alt 1366:Alt 1360:of 803:of 791:of 772:is 768:If 761:in 659:If 638:of 575:of 506:not 403:ker 361:(1) 352:of 332:if 328:or 214:of 206:on 37:In 5617:: 5582:MR 5580:. 5570:. 5476:. 5456:. 5450:MR 5448:. 5438:. 5426:. 5418:; 5381:^ 5258:. 4636:Ad 4570:Tr 4401:Tr 4164:. 4143:∩ 4141:Ht 4103:, 3701:ht 3688:Ht 3479:, 3429:, 3425:, 2907:. 2852:. 2542:. 2503:). 2080:, 1831::= 1801:: 1647:: 1381:∧ 1377:= 1350:, 1336:, 821:). 816:= 664:= 647:= 546:→ 419::= 392:: 312:. 306:Tr 268:Tr 230:→ 157:. 105:. 5607:. 5588:. 5566:: 5546:. 5523:. 5486:. 5464:. 5434:: 5392:) 5388:( 5345:χ 5341:g 5339:( 5337:χ 5333:g 5320:. 5318:N 5314:G 5271:h 5220:m 5164:, 5150:h 5142:H 5138:, 5133:) 5130:H 5127:( 5120:e 5110:m 5096:= 5093:) 5090:H 5087:( 5048:h 5024:h 5000:g 4929:h 4901:g 4887:. 4875:) 4870:X 4866:e 4862:( 4852:X 4847:= 4844:) 4841:X 4838:( 4798:X 4747:g 4739:X 4719:G 4699:g 4679:) 4676:X 4673:( 4660:= 4657:) 4654:) 4651:X 4648:( 4640:g 4632:( 4610:. 4598:) 4593:) 4590:X 4587:( 4580:e 4576:( 4567:= 4564:) 4561:X 4558:( 4496:g 4448:g 4434:. 4422:) 4419:) 4416:g 4413:( 4407:( 4398:= 4395:) 4392:g 4389:( 4309:G 4265:G 4223:j 4211:) 4209:V 4204:V 4202:I 4198:ρ 4194:χ 4185:) 4183:g 4181:( 4179:χ 4160:T 4154:ψ 4150:θ 4145:K 4138:t 4133:ψ 4128:θ 4123:0 4119:1 4115:ψ 4111:θ 4107:) 4105:K 4101:H 4099:( 4095:T 4074:, 4064:K 4058:t 4055:H 4050:1 4043:t 4034:, 4029:K 4023:t 4020:H 4015:1 4008:t 4002:) 3997:t 3989:( 3977:T 3971:t 3963:= 3945:, 3940:K 3935:) 3930:K 3924:t 3921:H 3916:1 3909:t 3903:] 3898:t 3890:[ 3885:( 3873:T 3867:t 3859:= 3841:, 3836:K 3831:) 3826:G 3818:( 3808:= 3794:G 3786:, 3781:G 3754:K 3750:H 3746:K 3742:H 3738:ψ 3734:θ 3719:H 3715:h 3711:) 3709:h 3707:( 3705:θ 3698:t 3696:( 3694:θ 3685:t 3679:θ 3661:, 3656:K 3651:) 3646:K 3640:t 3637:H 3632:1 3625:t 3619:] 3614:t 3606:[ 3601:( 3594:T 3588:t 3580:= 3575:K 3570:) 3565:G 3557:( 3542:H 3538:θ 3524:K 3521:t 3518:H 3513:T 3507:t 3499:= 3496:G 3483:) 3481:K 3477:H 3475:( 3471:G 3467:G 3463:K 3459:G 3455:H 3412:H 3408:G 3400:H 3396:θ 3392:G 3388:H 3381:H 3377:θ 3360:. 3356:) 3350:1 3342:i 3338:t 3334:h 3329:i 3325:t 3320:( 3311:H 3303:1 3295:i 3291:t 3287:h 3282:i 3278:t 3271:: 3265:i 3257:= 3254:) 3251:h 3248:( 3243:G 3225:H 3221:h 3204:, 3199:n 3195:t 3191:H 3177:1 3173:t 3169:H 3166:= 3163:G 3150:H 3138:G 3134:H 3130:G 3126:H 3122:G 3117:θ 3111:ρ 3106:ρ 3099:G 3095:H 3091:ρ 3084:θ 3078:G 3071:G 3067:G 3058:θ 3053:H 3049:H 3045:G 3041:H 3037:G 3033:G 3029:χ 3010:H 3000:H 2992:, 2983:= 2978:G 2967:, 2962:G 2941:G 2936:θ 2931:G 2927:G 2917:θ 2913:G 2905:H 2901:θ 2897:H 2891:H 2889:χ 2884:G 2880:χ 2876:G 2872:H 2832:) 2829:g 2826:( 2821:2 2813:) 2810:g 2807:( 2802:1 2794:= 2791:) 2788:g 2785:( 2782:] 2777:2 2764:1 2756:[ 2732:) 2729:) 2726:g 2723:( 2718:2 2707:) 2704:g 2701:( 2696:1 2688:( 2685:= 2682:) 2679:g 2676:( 2671:2 2658:1 2631:2 2627:V 2620:G 2617:: 2612:2 2585:1 2581:V 2574:G 2571:: 2566:1 2547:G 2535:4 2532:D 2527:8 2519:Q 2475:| 2471:G 2467:| 2457:| 2453:G 2449:| 2438:G 2430:G 2426:G 2421:. 2419:G 2415:G 2406:. 2404:G 2400:G 2396:G 2390:χ 2386:g 2384:( 2382:χ 2377:G 2373:g 2369:χ 2361:G 2357:G 2346:G 2338:G 2309:h 2305:g 2301:g 2291:g 2289:( 2286:G 2284:C 2278:G 2272:i 2270:χ 2236:0 2222:h 2219:, 2216:g 2204:, 2200:| 2196:) 2193:g 2190:( 2185:G 2181:C 2176:| 2169:{ 2164:= 2155:) 2152:h 2149:( 2144:i 2133:) 2130:g 2127:( 2122:i 2110:i 2087:G 2082:h 2078:g 2053:. 2050:j 2047:= 2044:i 2032:1 2025:, 2022:j 2016:i 2004:0 1998:{ 1993:= 1983:j 1975:, 1970:i 1943:) 1941:g 1939:( 1937:β 1927:) 1925:g 1923:( 1921:β 1896:) 1893:g 1890:( 1881:) 1878:g 1875:( 1867:G 1861:g 1849:| 1845:G 1841:| 1836:1 1820:, 1795:G 1766:ω 1757:ω 1751:ω 1745:1 1739:2 1736:χ 1727:ω 1721:ω 1716:1 1710:1 1707:χ 1699:1 1694:1 1689:1 1683:1 1675:) 1673:u 1671:( 1666:) 1664:u 1662:( 1645:u 1624:, 1618:1 1615:= 1610:3 1606:u 1599:u 1593:= 1588:3 1584:C 1557:G 1551:g 1531:1 1528:= 1525:) 1522:g 1519:( 1506:G 1496:G 1492:G 1488:G 1453:. 1445:2 1429:) 1415:( 1411:= 1383:ρ 1379:ρ 1375:ρ 1362:ρ 1353:ρ 1343:σ 1341:⊗ 1339:ρ 1329:σ 1327:⊕ 1325:ρ 1306:] 1302:) 1297:2 1293:g 1289:( 1276:+ 1271:2 1266:) 1262:) 1259:g 1256:( 1242:( 1236:[ 1228:2 1225:1 1219:= 1216:) 1213:g 1210:( 1196:2 1191:m 1188:y 1185:S 1152:] 1148:) 1143:2 1139:g 1135:( 1117:2 1112:) 1108:) 1105:g 1102:( 1088:( 1082:[ 1074:2 1071:1 1065:= 1062:) 1059:g 1056:( 1042:2 1037:t 1034:l 1031:A 982:= 921:= 874:+ 861:= 832:G 818:C 814:F 809:G 805:G 797:G 793:G 785:) 783:F 781:( 770:F 765:. 763:G 759:x 738:) 735:1 732:( 724:) 721:x 718:( 709:] 706:) 703:x 700:( 695:G 691:C 687:: 684:G 681:[ 671:χ 666:C 662:F 656:. 649:C 645:F 640:g 632:m 628:χ 624:n 616:m 613:n 609:) 607:g 605:( 603:χ 597:. 595:H 591:H 584:G 562:0 551:. 548:F 544:G 539:F 531:F 527:G 502:ρ 485:, 481:} 477:) 474:1 471:( 458:= 455:) 452:g 449:( 433:G 427:g 423:{ 384:ρ 382:χ 373:F 369:G 359:χ 354:ρ 346:χ 334:ρ 320:ρ 318:χ 289:) 286:) 283:g 280:( 274:( 265:= 262:) 259:g 256:( 232:F 228:G 223:ρ 221:χ 216:ρ 208:V 204:G 196:) 194:V 190:G 186:ρ 181:F 167:V 153:2 34:. 20:)

Index

Orthogonality relation
Character (mathematics)
mathematics
group theory
group representation
function
group
trace
matrix
Georg Frobenius
representation theory of finite groups
complex
finite group
isomorphism
field
characteristic
Richard Brauer
modular representations
irreducible representations
classification of finite simple groups
proof
Feit–Thompson theorem
Burnside's theorem
Richard Brauer
Michio Suzuki
simple group
generalized quaternion group
Sylow 2-subgroup
finite-dimensional
vector space

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