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Commutator subgroup

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2306: 3772: 1213:. It is known that the least order of a finite group for which there exists two commutators whose product is not a commutator is 96; in fact there are two nonisomorphic groups of order 96 with this property. 2683: 2148: 2834: 3581: 3528: 3446: 2996: 2893: 2641: 2614: 2209: 3040: 1663: 3309: 1869: 3249: 2866: 545: 480:
However, the notation is somewhat arbitrary and there is a non-equivalent variant definition for the commutator that has the inverses on the right hand side of the equation:
317: 1188: 952: 903: 3183: 1932: 2497: 2046: 3396: 592: 2795: 2703: 1036: 3607: 2939: 2377: 1440: 1316: 1283: 779: 854: 1116: 639: 475: 388: 2459: 105: 2540: 999: 3466: 3357: 3125: 3092: 3064: 2763: 2743: 2723: 2584: 2564: 2428: 1466: 976: 428: 408: 250: 230: 202: 182: 148: 128: 1359: 1254: 678: 349: 2228: 150:. So in some sense it provides a measure of how far the group is from being abelian; the larger the commutator subgroup is, the "less abelian" the group is. 2386:, which may or may not be trivial. For an infinite group, the derived series need not terminate at a finite stage, and one can continue it to infinite 3718: 3982: 3953: 3931: 2649: 3974: 3104:}. Equivalently, if and only if the group equals its abelianization. See above for the definition of a group's abelianization. 4039: 4017: 3970: 3822: 1958: 4044: 4012: 2052: 2800: 2949: 2868:. As usual for objects defined by universal mapping properties, this shows the uniqueness of the abelianization 1323: 54: 3547: 3494: 3412: 2974: 2871: 2619: 2592: 2156: 3701: 3001: 1493: 3137:. Equivalently, if and only if the abelianization of the group is trivial. This is "opposite" to abelian. 2965: 51: 4007: 3269: 4034: 2391: 1687: 1193:
However, the product of two or more commutators need not be a commutator. A generic example is in the
3209: 2839: 2968:
of the category of groups, defined as a full subcategory whose inclusion functor has a left adjoint.
3923: 3542: 3489: 3407: 2317: 483: 255: 1160: 908: 859: 3810: 3531: 3143: 1878: 47: 3709: 2464: 1942: 1004: 65: 2012: 3362: 550: 3978: 3949: 3927: 3648: 3621: 2768: 2688: 1122: 1009: 3586: 2898: 2324: 1367: 1288: 721: 3661: 3631: 2945: 785: 352: 35: 1041: 597: 433: 361: 3788: 3638: 3317: 955: 68: 2436: 82: 2505: 2301:{\displaystyle \cdots \triangleleft G^{(2)}\triangleleft G^{(1)}\triangleleft G^{(0)}=G} 1263: 981: 3945: 3783: 3451: 3342: 3312: 3195: 3110: 3077: 3049: 3043: 2748: 2728: 2708: 2569: 2549: 2431: 2413: 2387: 1451: 1446: 961: 413: 393: 235: 215: 187: 167: 133: 113: 108: 72: 1332: 1227: 651: 322: 4028: 3535: 3482: 3478: 3334: 3129: 3096: 2383: 2220: 76: 3708:
induces an automorphism of the abelianization. Since the abelianization is abelian,
3614: 3403: 2399: 1150: 1138: 31: 3962: 3767:{\displaystyle \operatorname {Out} (G)\to \operatorname {Aut} (G^{\mbox{ab}})} 1194: 1145:. This is in fact a generalization of the second identity, since we can take 209: 159: 58: 1129:
is closed under inversion and conjugation. If in the third identity we take
699:
Here are some simple but useful commutator identities, true for any elements
17: 1953:
it shows that the commutator subgroup is stable under every endomorphism of
3992: 3903:, Translations of Mathematical Monographs, American Mathematical Society 692:= is always a commutator, and it is the only commutator if and only if 2952:
to the category of groups. The existence of the abelianization functor
1938: 1968:
The commutator subgroup can also be defined as the set of elements
1945:, some implications of which are explored below. Moreover, taking 2895:
up to canonical isomorphism, whereas the explicit construction
3133:
if and only if the derived group equals the group itself: =
2678:{\displaystyle \varphi :G\rightarrow G^{\operatorname {ab} }} 27:
Smallest normal subgroup by which the quotient is commutative
1937:
This shows that the commutator subgroup can be viewed as a
1137:, we get that the set of commutators is stable under any 2646:
There is a useful categorical interpretation of the map
2382:
For a finite group, the derived series terminates in a
64:
The commutator subgroup is important because it is the
3754: 3721: 3589: 3550: 3497: 3454: 3415: 3365: 3345: 3272: 3212: 3146: 3113: 3080: 3052: 3004: 2977: 2901: 2874: 2842: 2803: 2771: 2751: 2731: 2711: 2691: 2652: 2622: 2595: 2572: 2552: 2508: 2467: 2439: 2416: 2327: 2231: 2159: 2055: 2015: 1881: 1690: 1496: 1454: 1370: 1335: 1291: 1266: 1230: 1163: 1044: 1012: 984: 964: 911: 862: 788: 724: 654: 600: 553: 486: 436: 416: 396: 364: 325: 258: 238: 218: 190: 170: 136: 116: 85: 1329:
It follows from this definition that any element of
1965:, a property considerably stronger than normality. 3766: 3601: 3575: 3522: 3460: 3440: 3390: 3351: 3321:; this is weaker than solvable, which is the case 3303: 3243: 3177: 3119: 3086: 3058: 3034: 2990: 2933: 2887: 2860: 2828: 2789: 2757: 2737: 2717: 2697: 2677: 2635: 2608: 2578: 2558: 2534: 2491: 2453: 2422: 2371: 2300: 2203: 2142: 2040: 1972:of the group that have an expression as a product 1926: 1863: 1657: 1460: 1434: 1353: 1310: 1277: 1248: 1182: 1110: 1030: 993: 970: 946: 897: 848: 773: 672: 633: 586: 539: 469: 422: 402: 382: 343: 311: 244: 224: 196: 176: 142: 122: 99: 3199:; this is weaker than abelian, which is the case 3100:if and only if the derived group is trivial: = { 2143:{\displaystyle G^{(n)}:=\quad n\in \mathbf {N} } 1121:The first and second identities imply that the 2829:{\displaystyle F:G^{\operatorname {ab} }\to H} 688:is called a commutator. The identity element 1998:that can be rearranged to give the identity. 8: 3918:Dummit, David S.; Foote, Richard M. (2004), 3298: 3292: 3238: 3232: 3172: 3166: 3853: 3875: 3576:{\displaystyle \operatorname {SL} _{n}(k)} 3523:{\displaystyle \operatorname {GL} _{n}(k)} 3441:{\displaystyle \operatorname {SL} _{n}(k)} 75:of the original group by this subgroup is 3753: 3720: 3588: 3555: 3549: 3502: 3496: 3453: 3420: 3414: 3370: 3364: 3344: 3277: 3271: 3217: 3211: 3151: 3145: 3112: 3079: 3051: 3025: 3024: 3009: 3003: 2982: 2976: 2911: 2900: 2879: 2873: 2841: 2814: 2802: 2770: 2750: 2730: 2710: 2690: 2669: 2651: 2627: 2621: 2600: 2594: 2571: 2551: 2512: 2507: 2466: 2443: 2438: 2415: 2348: 2332: 2326: 2280: 2261: 2242: 2230: 2183: 2164: 2158: 2135: 2107: 2082: 2060: 2054: 2020: 2014: 1880: 1849: 1827: 1799: 1777: 1749: 1736: 1717: 1704: 1689: 1646: 1641: 1628: 1623: 1604: 1599: 1586: 1581: 1565: 1552: 1539: 1520: 1507: 1495: 1453: 1423: 1410: 1391: 1378: 1369: 1334: 1296: 1290: 1265: 1229: 1174: 1162: 1043: 1011: 983: 963: 935: 916: 910: 880: 867: 861: 834: 821: 805: 787: 741: 723: 653: 599: 552: 528: 515: 485: 435: 415: 395: 363: 324: 294: 281: 257: 237: 217: 189: 169: 135: 115: 89: 84: 3886: 3846: 3712:act trivially, hence this yields a map 2991:{\displaystyle G^{\operatorname {ab} }} 2888:{\displaystyle G^{\operatorname {ab} }} 2636:{\displaystyle G_{\operatorname {ab} }} 2609:{\displaystyle G^{\operatorname {ab} }} 2315:. This should not be confused with the 2204:{\displaystyle G^{(2)},G^{(3)},\ldots } 1665:, the commutator subgroup is normal in 3359:has derived subgroup equal to itself, 3035:{\displaystyle H_{1}(G,\mathbb {Z} )} 2398:, which eventually terminates at the 1658:{\displaystyle (\cdots )^{s}=\cdots } 1221:This motivates the definition of the 7: 3864: 2971:Another important interpretation of 2705:is universal for homomorphisms from 130:contains the commutator subgroup of 3993:"Derived Subgroups and Commutators" 3304:{\displaystyle G^{(\alpha )}=\{e\}} 2797:there exists a unique homomorphism 2219:, and so forth, and the descending 2006:This construction can be iterated: 3942:A First Course In Abstract Algebra 2948:of the inclusion functor from the 2944:The abelianization functor is the 1864:{\displaystyle f(\cdots )=\cdots } 25: 3315:, possibly infinite, is called a 3244:{\displaystyle G^{(n)}\neq \{e\}} 2861:{\displaystyle f=F\circ \varphi } 2136: 3660:The commutator subgroup of the 3637:The commutator subgroup of the 3620:The commutator subgroup of the 3488:The commutator subgroup of the 3477:The commutator subgroup of any 2542:is an abelian group called the 2128: 540:{\displaystyle =ghg^{-1}h^{-1}} 312:{\displaystyle =g^{-1}h^{-1}gh} 3761: 3746: 3737: 3734: 3728: 3700:Since the derived subgroup is 3570: 3564: 3517: 3511: 3435: 3429: 3377: 3371: 3325:is finite (a natural number). 3284: 3278: 3224: 3218: 3158: 3152: 3029: 3015: 2928: 2916: 2905: 2820: 2781: 2662: 2529: 2517: 2480: 2468: 2366: 2341: 2287: 2281: 2268: 2262: 2249: 2243: 2190: 2184: 2171: 2165: 2125: 2120: 2108: 2095: 2083: 2075: 2067: 2061: 2027: 2021: 1921: 1909: 1903: 1900: 1888: 1885: 1858: 1855: 1842: 1833: 1820: 1814: 1808: 1805: 1792: 1783: 1770: 1764: 1758: 1755: 1729: 1723: 1697: 1694: 1652: 1616: 1610: 1574: 1562: 1558: 1532: 1526: 1500: 1497: 1429: 1403: 1397: 1371: 1348: 1336: 1303: 1297: 1243: 1231: 1190:, to get the second identity. 1183:{\displaystyle x\mapsto x^{s}} 1167: 1102: 1099: 1093: 1084: 1078: 1072: 1066: 1063: 1051: 1048: 1022: 947:{\displaystyle g^{s}=sgs^{-1}} 898:{\displaystyle g^{s}=s^{-1}gs} 840: 814: 802: 789: 765: 753: 738: 725: 667: 655: 622: 610: 581: 569: 499: 487: 464: 452: 338: 326: 271: 259: 1: 3971:Graduate Texts in Mathematics 3178:{\displaystyle G^{(n)}=\{e\}} 1959:fully characteristic subgroup 1927:{\displaystyle f()\subseteq } 3823:target of the Artin transfer 3402:. This includes non-abelian 3066:with integral coefficients. 4013:Encyclopedia of Mathematics 2765:and homomorphism of groups 2589:. It is usually denoted by 2492:{\displaystyle \subseteq N} 4061: 3940:Fraleigh, John B. (1976), 3332: 2950:category of abelian groups 2461:is abelian if and only if 2396:transfinite derived series 2041:{\displaystyle G^{(0)}:=G} 390:, that is, if and only if 157: 3991:Suárez-Alvarez, Mariano. 3944:(2nd ed.), Reading: 3899:Suprunenko, D.A. (1976), 3854:Dummit & Foote (2004) 3391:{\displaystyle G^{(1)}=G} 587:{\displaystyle gh\neq hg} 2790:{\displaystyle f:G\to H} 2745:: for any abelian group 2698:{\displaystyle \varphi } 2394:, thereby obtaining the 1669:. For any homomorphism 1326:by all the commutators. 1031:{\displaystyle f:G\to H} 3615:field with two elements 3602:{\displaystyle n\neq 2} 2934:{\displaystyle G\to G/} 2372:{\displaystyle G_{n}:=} 2213:second derived subgroup 1435:{\displaystyle \cdots } 1311:{\displaystyle G^{(1)}} 774:{\displaystyle ^{-1}=,} 34:, more specifically in 3768: 3704:, any automorphism of 3691:} is = {1, −1}. 3603: 3577: 3524: 3462: 3442: 3392: 3353: 3305: 3245: 3179: 3121: 3088: 3060: 3036: 2992: 2966:reflective subcategory 2935: 2889: 2862: 2830: 2791: 2759: 2739: 2719: 2699: 2679: 2637: 2610: 2580: 2560: 2536: 2493: 2455: 2424: 2373: 2302: 2217:third derived subgroup 2205: 2144: 2042: 1928: 1865: 1659: 1462: 1436: 1355: 1312: 1279: 1250: 1184: 1149:to be the conjugation 1112: 1032: 995: 972: 948: 899: 850: 849:{\displaystyle ^{s}=,} 775: 674: 635: 588: 541: 471: 430:commute. In general, 424: 404: 384: 345: 313: 246: 226: 198: 178: 144: 124: 101: 4008:"Commutator subgroup" 3924:John Wiley & Sons 3769: 3604: 3578: 3525: 3463: 3443: 3408:special linear groups 3393: 3354: 3306: 3246: 3180: 3122: 3089: 3061: 3037: 2993: 2936: 2890: 2863: 2831: 2792: 2760: 2740: 2720: 2700: 2680: 2638: 2611: 2581: 2561: 2537: 2494: 2456: 2425: 2392:transfinite recursion 2374: 2303: 2206: 2145: 2043: 1929: 1866: 1660: 1463: 1437: 1356: 1322:: it is the subgroup 1313: 1280: 1251: 1185: 1113: 1111:{\displaystyle f()=.} 1033: 996: 973: 949: 900: 851: 776: 675: 636: 634:{\displaystyle gh=hg} 589: 542: 472: 470:{\displaystyle gh=hg} 425: 405: 385: 383:{\displaystyle gh=hg} 346: 314: 247: 227: 199: 179: 145: 125: 102: 4040:Functional subgroups 3719: 3587: 3548: 3543:special linear group 3495: 3490:general linear group 3452: 3413: 3363: 3343: 3270: 3210: 3144: 3111: 3078: 3050: 3002: 2975: 2899: 2872: 2840: 2801: 2769: 2749: 2729: 2725:to an abelian group 2709: 2689: 2650: 2620: 2593: 2570: 2550: 2506: 2465: 2437: 2414: 2325: 2318:lower central series 2229: 2157: 2053: 2013: 1879: 1688: 1494: 1452: 1368: 1333: 1289: 1264: 1228: 1161: 1042: 1010: 982: 962: 909: 860: 786: 722: 652: 598: 551: 484: 434: 414: 394: 362: 323: 256: 236: 216: 188: 168: 134: 114: 83: 4045:Subgroup properties 3793:The abelianization 3710:inner automorphisms 2960:makes the category 2454:{\displaystyle G/N} 1651: 1633: 1609: 1591: 1490:. Moreover, since 1223:commutator subgroup 905:(or, respectively, 100:{\displaystyle G/N} 40:commutator subgroup 3764: 3758: 3599: 3573: 3520: 3458: 3448:for a fixed field 3438: 3388: 3349: 3301: 3261:non-solvable group 3241: 3175: 3117: 3084: 3056: 3032: 2988: 2931: 2885: 2858: 2826: 2787: 2755: 2735: 2715: 2695: 2675: 2633: 2606: 2576: 2556: 2535:{\displaystyle G/} 2532: 2489: 2451: 2420: 2369: 2321:, whose terms are 2298: 2201: 2140: 2038: 1943:category of groups 1924: 1861: 1655: 1637: 1619: 1595: 1577: 1458: 1432: 1351: 1308: 1278:{\displaystyle G'} 1275: 1246: 1180: 1125:of commutators in 1108: 1028: 994:{\displaystyle s,} 991: 968: 944: 895: 846: 771: 670: 631: 584: 537: 467: 420: 400: 380: 341: 319:. The commutator 309: 242: 222: 194: 174: 140: 120: 97: 79:. In other words, 3757: 3649:alternating group 3622:alternating group 3461:{\displaystyle k} 3398:, it is called a 3352:{\displaystyle G} 3339:Whenever a group 3318:hypoabelian group 3120:{\displaystyle G} 3087:{\displaystyle G} 3070:Classes of groups 3059:{\displaystyle G} 2941:shows existence. 2758:{\displaystyle H} 2738:{\displaystyle H} 2718:{\displaystyle G} 2579:{\displaystyle G} 2559:{\displaystyle G} 2423:{\displaystyle G} 1957:: that is, is a 1461:{\displaystyle n} 1256:(also called the 971:{\displaystyle g} 423:{\displaystyle h} 403:{\displaystyle g} 245:{\displaystyle h} 225:{\displaystyle g} 197:{\displaystyle h} 177:{\displaystyle g} 143:{\displaystyle G} 123:{\displaystyle N} 16:(Redirected from 4052: 4021: 3996: 3987: 3958: 3936: 3922:(3rd ed.), 3920:Abstract Algebra 3906: 3905:, Theorem II.9.4 3904: 3896: 3890: 3884: 3878: 3873: 3867: 3862: 3856: 3851: 3805: <  3801:' of a subgroup 3773: 3771: 3770: 3765: 3760: 3759: 3755: 3667:= {1, −1, 3662:quaternion group 3632:Klein four group 3608: 3606: 3605: 3600: 3582: 3580: 3579: 3574: 3560: 3559: 3529: 3527: 3526: 3521: 3507: 3506: 3467: 3465: 3464: 3459: 3447: 3445: 3444: 3439: 3425: 3424: 3397: 3395: 3394: 3389: 3381: 3380: 3358: 3356: 3355: 3350: 3310: 3308: 3307: 3302: 3288: 3287: 3250: 3248: 3247: 3242: 3228: 3227: 3184: 3182: 3181: 3176: 3162: 3161: 3126: 3124: 3123: 3118: 3093: 3091: 3090: 3085: 3065: 3063: 3062: 3057: 3041: 3039: 3038: 3033: 3028: 3014: 3013: 2997: 2995: 2994: 2989: 2987: 2986: 2940: 2938: 2937: 2932: 2915: 2894: 2892: 2891: 2886: 2884: 2883: 2867: 2865: 2864: 2859: 2835: 2833: 2832: 2827: 2819: 2818: 2796: 2794: 2793: 2788: 2764: 2762: 2761: 2756: 2744: 2742: 2741: 2736: 2724: 2722: 2721: 2716: 2704: 2702: 2701: 2696: 2684: 2682: 2681: 2676: 2674: 2673: 2642: 2640: 2639: 2634: 2632: 2631: 2615: 2613: 2612: 2607: 2605: 2604: 2585: 2583: 2582: 2577: 2565: 2563: 2562: 2557: 2541: 2539: 2538: 2533: 2516: 2498: 2496: 2495: 2490: 2460: 2458: 2457: 2452: 2447: 2429: 2427: 2426: 2421: 2378: 2376: 2375: 2370: 2359: 2358: 2337: 2336: 2307: 2305: 2304: 2299: 2291: 2290: 2272: 2271: 2253: 2252: 2210: 2208: 2207: 2202: 2194: 2193: 2175: 2174: 2149: 2147: 2146: 2141: 2139: 2124: 2123: 2099: 2098: 2071: 2070: 2047: 2045: 2044: 2039: 2031: 2030: 1933: 1931: 1930: 1925: 1870: 1868: 1867: 1862: 1854: 1853: 1832: 1831: 1804: 1803: 1782: 1781: 1754: 1753: 1741: 1740: 1722: 1721: 1709: 1708: 1664: 1662: 1661: 1656: 1650: 1645: 1632: 1627: 1608: 1603: 1590: 1585: 1570: 1569: 1557: 1556: 1544: 1543: 1525: 1524: 1512: 1511: 1486:are elements of 1467: 1465: 1464: 1459: 1441: 1439: 1438: 1433: 1428: 1427: 1415: 1414: 1396: 1395: 1383: 1382: 1360: 1358: 1357: 1354:{\displaystyle } 1352: 1317: 1315: 1314: 1309: 1307: 1306: 1284: 1282: 1281: 1276: 1274: 1258:derived subgroup 1255: 1253: 1252: 1249:{\displaystyle } 1247: 1189: 1187: 1186: 1181: 1179: 1178: 1117: 1115: 1114: 1109: 1037: 1035: 1034: 1029: 1000: 998: 997: 992: 977: 975: 974: 969: 953: 951: 950: 945: 943: 942: 921: 920: 904: 902: 901: 896: 888: 887: 872: 871: 855: 853: 852: 847: 839: 838: 826: 825: 810: 809: 780: 778: 777: 772: 749: 748: 679: 677: 676: 673:{\displaystyle } 671: 640: 638: 637: 632: 593: 591: 590: 585: 546: 544: 543: 538: 536: 535: 523: 522: 476: 474: 473: 468: 429: 427: 426: 421: 409: 407: 406: 401: 389: 387: 386: 381: 353:identity element 351:is equal to the 350: 348: 347: 344:{\displaystyle } 342: 318: 316: 315: 310: 302: 301: 289: 288: 251: 249: 248: 243: 231: 229: 228: 223: 203: 201: 200: 195: 183: 181: 180: 175: 149: 147: 146: 141: 129: 127: 126: 121: 106: 104: 103: 98: 93: 44:derived subgroup 36:abstract algebra 21: 4060: 4059: 4055: 4054: 4053: 4051: 4050: 4049: 4025: 4024: 4006: 4003: 3990: 3985: 3961: 3956: 3939: 3934: 3917: 3914: 3909: 3898: 3897: 3893: 3885: 3881: 3874: 3870: 3863: 3859: 3852: 3848: 3844: 3789:Nilpotent group 3780: 3749: 3717: 3716: 3698: 3655: 3645: 3639:symmetric group 3629: 3585: 3584: 3551: 3546: 3545: 3498: 3493: 3492: 3474: 3450: 3449: 3416: 3411: 3410: 3366: 3361: 3360: 3341: 3340: 3337: 3331: 3273: 3268: 3267: 3213: 3208: 3207: 3147: 3142: 3141: 3109: 3108: 3076: 3075: 3072: 3048: 3047: 3005: 3000: 2999: 2978: 2973: 2972: 2897: 2896: 2875: 2870: 2869: 2838: 2837: 2810: 2799: 2798: 2767: 2766: 2747: 2746: 2727: 2726: 2707: 2706: 2687: 2686: 2665: 2648: 2647: 2623: 2618: 2617: 2596: 2591: 2590: 2568: 2567: 2548: 2547: 2504: 2503: 2463: 2462: 2435: 2434: 2412: 2411: 2408: 2388:ordinal numbers 2344: 2328: 2323: 2322: 2276: 2257: 2238: 2227: 2226: 2211:are called the 2179: 2160: 2155: 2154: 2103: 2078: 2056: 2051: 2050: 2016: 2011: 2010: 2004: 1997: 1988: 1982: 1877: 1876: 1845: 1823: 1795: 1773: 1745: 1732: 1713: 1700: 1686: 1685: 1561: 1548: 1535: 1516: 1503: 1492: 1491: 1485: 1476: 1450: 1449: 1419: 1406: 1387: 1374: 1366: 1365: 1361:is of the form 1331: 1330: 1292: 1287: 1286: 1267: 1262: 1261: 1226: 1225: 1219: 1170: 1159: 1158: 1040: 1039: 1008: 1007: 980: 979: 960: 959: 931: 912: 907: 906: 876: 863: 858: 857: 830: 817: 801: 784: 783: 737: 720: 719: 650: 649: 596: 595: 549: 548: 547:in which case 524: 511: 482: 481: 432: 431: 412: 411: 392: 391: 360: 359: 358:if and only if 321: 320: 290: 277: 254: 253: 234: 233: 214: 213: 186: 185: 166: 165: 162: 156: 132: 131: 112: 111: 81: 80: 69:normal subgroup 28: 23: 22: 15: 12: 11: 5: 4058: 4056: 4048: 4047: 4042: 4037: 4027: 4026: 4023: 4022: 4002: 4001:External links 3999: 3998: 3997: 3988: 3983: 3959: 3954: 3946:Addison-Wesley 3937: 3932: 3913: 3910: 3908: 3907: 3891: 3889:, p. 108) 3887:Fraleigh (1976 3879: 3876:Suárez-Alvarez 3868: 3857: 3845: 3843: 3840: 3839: 3838: 3791: 3786: 3784:Solvable group 3779: 3776: 3775: 3774: 3763: 3752: 3748: 3745: 3742: 3739: 3736: 3733: 3730: 3727: 3724: 3702:characteristic 3697: 3694: 3693: 3692: 3658: 3653: 3643: 3635: 3627: 3618: 3598: 3595: 3592: 3583:provided that 3572: 3569: 3566: 3563: 3558: 3554: 3519: 3516: 3513: 3510: 3505: 3501: 3486: 3473: 3470: 3457: 3437: 3434: 3431: 3428: 3423: 3419: 3387: 3384: 3379: 3376: 3373: 3369: 3348: 3333:Main article: 3330: 3327: 3313:ordinal number 3300: 3297: 3294: 3291: 3286: 3283: 3280: 3276: 3240: 3237: 3234: 3231: 3226: 3223: 3220: 3216: 3196:solvable group 3174: 3171: 3168: 3165: 3160: 3157: 3154: 3150: 3116: 3083: 3071: 3068: 3055: 3044:homology group 3031: 3027: 3023: 3020: 3017: 3012: 3008: 2985: 2981: 2930: 2927: 2924: 2921: 2918: 2914: 2910: 2907: 2904: 2882: 2878: 2857: 2854: 2851: 2848: 2845: 2825: 2822: 2817: 2813: 2809: 2806: 2786: 2783: 2780: 2777: 2774: 2754: 2734: 2714: 2694: 2672: 2668: 2664: 2661: 2658: 2655: 2630: 2626: 2603: 2599: 2575: 2555: 2544:abelianization 2531: 2528: 2525: 2522: 2519: 2515: 2511: 2488: 2485: 2482: 2479: 2476: 2473: 2470: 2450: 2446: 2442: 2432:quotient group 2419: 2410:Given a group 2407: 2406:Abelianization 2404: 2402:of the group. 2368: 2365: 2362: 2357: 2354: 2351: 2347: 2343: 2340: 2335: 2331: 2313:derived series 2311:is called the 2309: 2308: 2297: 2294: 2289: 2286: 2283: 2279: 2275: 2270: 2267: 2264: 2260: 2256: 2251: 2248: 2245: 2241: 2237: 2234: 2200: 2197: 2192: 2189: 2186: 2182: 2178: 2173: 2170: 2167: 2163: 2151: 2150: 2138: 2134: 2131: 2127: 2122: 2119: 2116: 2113: 2110: 2106: 2102: 2097: 2094: 2091: 2088: 2085: 2081: 2077: 2074: 2069: 2066: 2063: 2059: 2048: 2037: 2034: 2029: 2026: 2023: 2019: 2003: 2002:Derived series 2000: 1993: 1986: 1980: 1923: 1920: 1917: 1914: 1911: 1908: 1905: 1902: 1899: 1896: 1893: 1890: 1887: 1884: 1873: 1872: 1860: 1857: 1852: 1848: 1844: 1841: 1838: 1835: 1830: 1826: 1822: 1819: 1816: 1813: 1810: 1807: 1802: 1798: 1794: 1791: 1788: 1785: 1780: 1776: 1772: 1769: 1766: 1763: 1760: 1757: 1752: 1748: 1744: 1739: 1735: 1731: 1728: 1725: 1720: 1716: 1712: 1707: 1703: 1699: 1696: 1693: 1654: 1649: 1644: 1640: 1636: 1631: 1626: 1622: 1618: 1615: 1612: 1607: 1602: 1598: 1594: 1589: 1584: 1580: 1576: 1573: 1568: 1564: 1560: 1555: 1551: 1547: 1542: 1538: 1534: 1531: 1528: 1523: 1519: 1515: 1510: 1506: 1502: 1499: 1481: 1472: 1457: 1447:natural number 1443: 1442: 1431: 1426: 1422: 1418: 1413: 1409: 1405: 1402: 1399: 1394: 1390: 1386: 1381: 1377: 1373: 1350: 1347: 1344: 1341: 1338: 1305: 1302: 1299: 1295: 1273: 1270: 1260:, and denoted 1245: 1242: 1239: 1236: 1233: 1218: 1215: 1177: 1173: 1169: 1166: 1119: 1118: 1107: 1104: 1101: 1098: 1095: 1092: 1089: 1086: 1083: 1080: 1077: 1074: 1071: 1068: 1065: 1062: 1059: 1056: 1053: 1050: 1047: 1027: 1024: 1021: 1018: 1015: 1001: 990: 987: 967: 941: 938: 934: 930: 927: 924: 919: 915: 894: 891: 886: 883: 879: 875: 870: 866: 845: 842: 837: 833: 829: 824: 820: 816: 813: 808: 804: 800: 797: 794: 791: 781: 770: 767: 764: 761: 758: 755: 752: 747: 744: 740: 736: 733: 730: 727: 669: 666: 663: 660: 657: 644:An element of 630: 627: 624: 621: 618: 615: 612: 609: 606: 603: 583: 580: 577: 574: 571: 568: 565: 562: 559: 556: 534: 531: 527: 521: 518: 514: 510: 507: 504: 501: 498: 495: 492: 489: 466: 463: 460: 457: 454: 451: 448: 445: 442: 439: 419: 399: 379: 376: 373: 370: 367: 340: 337: 334: 331: 328: 308: 305: 300: 297: 293: 287: 284: 280: 276: 273: 270: 267: 264: 261: 241: 221: 193: 173: 158:Main article: 155: 152: 139: 119: 109:if and only if 96: 92: 88: 73:quotient group 71:such that the 61:of the group. 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 4057: 4046: 4043: 4041: 4038: 4036: 4033: 4032: 4030: 4019: 4015: 4014: 4009: 4005: 4004: 4000: 3994: 3989: 3986: 3984:0-387-95385-X 3980: 3976: 3972: 3968: 3964: 3960: 3957: 3955:0-201-01984-1 3951: 3947: 3943: 3938: 3935: 3933:0-471-43334-9 3929: 3925: 3921: 3916: 3915: 3911: 3902: 3901:Matrix groups 3895: 3892: 3888: 3883: 3880: 3877: 3872: 3869: 3866: 3861: 3858: 3855: 3850: 3847: 3841: 3836: 3832: 3828: 3824: 3820: 3816: 3812: 3808: 3804: 3800: 3796: 3792: 3790: 3787: 3785: 3782: 3781: 3777: 3750: 3743: 3740: 3731: 3725: 3722: 3715: 3714: 3713: 3711: 3707: 3703: 3695: 3690: 3686: 3682: 3678: 3674: 3670: 3666: 3663: 3659: 3656: 3650: 3646: 3640: 3636: 3633: 3626: 3623: 3619: 3616: 3612: 3596: 3593: 3590: 3567: 3561: 3556: 3552: 3544: 3540: 3537: 3536:division ring 3533: 3514: 3508: 3503: 3499: 3491: 3487: 3484: 3480: 3479:abelian group 3476: 3475: 3471: 3469: 3455: 3432: 3426: 3421: 3417: 3409: 3405: 3404:simple groups 3401: 3400:perfect group 3385: 3382: 3374: 3367: 3346: 3336: 3335:Perfect group 3329:Perfect group 3328: 3326: 3324: 3320: 3319: 3314: 3295: 3289: 3281: 3274: 3266:A group with 3264: 3262: 3258: 3254: 3235: 3229: 3221: 3214: 3206:A group with 3204: 3202: 3198: 3197: 3192: 3188: 3169: 3163: 3155: 3148: 3140:A group with 3138: 3136: 3132: 3131: 3130:perfect group 3114: 3105: 3103: 3099: 3098: 3097:abelian group 3081: 3069: 3067: 3053: 3045: 3021: 3018: 3010: 3006: 2983: 2979: 2969: 2967: 2963: 2959: 2955: 2951: 2947: 2942: 2925: 2922: 2919: 2912: 2908: 2902: 2880: 2876: 2855: 2852: 2849: 2846: 2843: 2823: 2815: 2811: 2807: 2804: 2784: 2778: 2775: 2772: 2752: 2732: 2712: 2692: 2670: 2666: 2659: 2656: 2653: 2644: 2628: 2624: 2601: 2597: 2588: 2573: 2553: 2545: 2526: 2523: 2520: 2513: 2509: 2502:The quotient 2500: 2486: 2483: 2477: 2474: 2471: 2448: 2444: 2440: 2433: 2417: 2405: 2403: 2401: 2397: 2393: 2389: 2385: 2384:perfect group 2380: 2363: 2360: 2355: 2352: 2349: 2345: 2338: 2333: 2329: 2320: 2319: 2314: 2295: 2292: 2284: 2277: 2273: 2265: 2258: 2254: 2246: 2239: 2235: 2232: 2225: 2224: 2223: 2222: 2221:normal series 2218: 2214: 2198: 2195: 2187: 2180: 2176: 2168: 2161: 2132: 2129: 2117: 2114: 2111: 2104: 2100: 2092: 2089: 2086: 2079: 2072: 2064: 2057: 2049: 2035: 2032: 2024: 2017: 2009: 2008: 2007: 2001: 1999: 1996: 1992: 1985: 1979: 1975: 1971: 1966: 1964: 1960: 1956: 1952: 1948: 1944: 1940: 1935: 1918: 1915: 1912: 1906: 1897: 1894: 1891: 1882: 1850: 1846: 1839: 1836: 1828: 1824: 1817: 1811: 1800: 1796: 1789: 1786: 1778: 1774: 1767: 1761: 1750: 1746: 1742: 1737: 1733: 1726: 1718: 1714: 1710: 1705: 1701: 1691: 1684: 1683: 1682: 1680: 1676: 1672: 1668: 1647: 1642: 1638: 1634: 1629: 1624: 1620: 1613: 1605: 1600: 1596: 1592: 1587: 1582: 1578: 1571: 1566: 1553: 1549: 1545: 1540: 1536: 1529: 1521: 1517: 1513: 1508: 1504: 1489: 1484: 1480: 1475: 1471: 1455: 1448: 1424: 1420: 1416: 1411: 1407: 1400: 1392: 1388: 1384: 1379: 1375: 1364: 1363: 1362: 1345: 1342: 1339: 1327: 1325: 1321: 1300: 1293: 1271: 1268: 1259: 1240: 1237: 1234: 1224: 1216: 1214: 1212: 1208: 1204: 1200: 1196: 1191: 1175: 1171: 1164: 1156: 1152: 1148: 1144: 1140: 1136: 1132: 1128: 1124: 1105: 1096: 1090: 1087: 1081: 1075: 1069: 1060: 1057: 1054: 1045: 1025: 1019: 1016: 1013: 1006: 1002: 988: 985: 965: 957: 939: 936: 932: 928: 925: 922: 917: 913: 892: 889: 884: 881: 877: 873: 868: 864: 843: 835: 831: 827: 822: 818: 811: 806: 798: 795: 792: 782: 768: 762: 759: 756: 750: 745: 742: 734: 731: 728: 718: 717: 716: 714: 710: 706: 702: 697: 695: 691: 687: 683: 664: 661: 658: 647: 642: 628: 625: 619: 616: 613: 607: 604: 601: 578: 575: 572: 566: 563: 560: 557: 554: 532: 529: 525: 519: 516: 512: 508: 505: 502: 496: 493: 490: 478: 461: 458: 455: 449: 446: 443: 440: 437: 417: 397: 377: 374: 371: 368: 365: 357: 354: 335: 332: 329: 306: 303: 298: 295: 291: 285: 282: 278: 274: 268: 265: 262: 239: 219: 211: 207: 191: 171: 164:For elements 161: 153: 151: 137: 117: 110: 94: 90: 86: 78: 74: 70: 67: 62: 60: 56: 53: 49: 45: 41: 37: 33: 19: 18:Derived group 4035:Group theory 4011: 3966: 3941: 3919: 3900: 3894: 3882: 3871: 3860: 3849: 3834: 3830: 3826: 3818: 3814: 3806: 3802: 3798: 3794: 3705: 3699: 3696:Map from Out 3688: 3684: 3680: 3676: 3672: 3668: 3664: 3651: 3641: 3624: 3610: 3538: 3399: 3338: 3322: 3316: 3265: 3260: 3259:is called a 3256: 3252: 3205: 3200: 3194: 3193:is called a 3190: 3186: 3139: 3134: 3128: 3106: 3101: 3095: 3073: 3042:, the first 2970: 2961: 2957: 2953: 2946:left adjoint 2943: 2645: 2587:made abelian 2586: 2543: 2501: 2409: 2400:perfect core 2395: 2381: 2316: 2312: 2310: 2216: 2212: 2152: 2005: 1994: 1990: 1983: 1977: 1973: 1969: 1967: 1962: 1954: 1950: 1946: 1936: 1874: 1678: 1674: 1670: 1666: 1487: 1482: 1478: 1473: 1469: 1468:, where the 1444: 1328: 1319: 1257: 1222: 1220: 1210: 1206: 1202: 1198: 1192: 1154: 1151:automorphism 1146: 1142: 1139:endomorphism 1134: 1130: 1126: 1120: 1005:homomorphism 712: 708: 704: 700: 698: 696:is abelian. 693: 689: 685: 681: 648:of the form 645: 643: 594:but instead 479: 355: 205: 163: 63: 43: 39: 29: 3963:Lang, Serge 3865:Lang (2002) 3613:is not the 3541:equals the 2153:The groups 711:of a group 204:of a group 154:Commutators 107:is abelian 59:commutators 57:by all the 32:mathematics 4029:Categories 3912:References 3809:of finite 2836:such that 2685:. Namely 1217:Definition 1195:free group 210:commutator 160:Commutator 4018:EMS Press 3821:) is the 3744:⁡ 3738:→ 3726:⁡ 3687:, − 3679:, − 3671:, − 3594:≠ 3562:⁡ 3509:⁡ 3427:⁡ 3311:for some 3282:α 3230:≠ 3185:for some 2906:→ 2856:φ 2853:∘ 2821:→ 2782:→ 2693:φ 2663:→ 2654:φ 2484:⊆ 2353:− 2274:◃ 2255:◃ 2236:◃ 2233:⋯ 2199:… 2133:∈ 2115:− 2090:− 1907:⊆ 1812:⋯ 1727:⋯ 1614:⋯ 1530:⋯ 1445:for some 1401:⋯ 1324:generated 1168:↦ 1023:→ 956:conjugate 954:) is the 937:− 882:− 743:− 680:for some 561:≠ 530:− 517:− 296:− 283:− 55:generated 3975:Springer 3965:(2002), 3778:See also 3472:Examples 3406:and the 3251:for all 3107:A group 3074:A group 1875:so that 1272:′ 1003:for any 66:smallest 52:subgroup 4020:, 2001 3967:Algebra 3647:is the 3630:is the 3530:over a 3483:trivial 1941:on the 1939:functor 77:abelian 50:is the 3981:  3952:  3930:  3825:  3094:is an 2998:is as 856:where 208:, the 38:, the 3842:Notes 3811:index 3534:or a 3532:field 3203:= 1. 3127:is a 1318:) of 48:group 46:of a 3979:ISBN 3950:ISBN 3928:ISBN 2430:, a 2390:via 1989:... 1477:and 684:and 410:and 232:and 184:and 3741:Aut 3723:Out 3609:or 3481:is 3255:in 3189:in 3046:of 2954:Grp 2616:or 2566:or 2546:of 1961:of 1285:or 1197:on 1153:on 1141:of 1123:set 978:by 958:of 252:is 212:of 42:or 30:In 4031:: 4016:, 4010:, 3977:, 3973:, 3969:, 3948:, 3926:, 3837:). 3756:ab 3683:, 3675:, 3553:SL 3500:GL 3468:. 3418:SL 3263:. 2984:ab 2964:a 2962:Ab 2958:Ab 2956:→ 2881:ab 2816:ab 2671:ab 2643:. 2629:ab 2602:ab 2499:. 2379:. 2339::= 2215:, 2073::= 2033::= 1976:= 1949:= 1934:. 1681:, 1677:→ 1673:: 1157:, 1133:= 1038:, 715:: 707:, 703:, 641:. 477:. 3995:. 3835:H 3833:, 3831:G 3829:( 3827:T 3819:H 3817:: 3815:G 3813:( 3807:G 3803:H 3799:H 3797:/ 3795:H 3762:) 3751:G 3747:( 3735:) 3732:G 3729:( 3706:G 3689:k 3685:k 3681:j 3677:j 3673:i 3669:i 3665:Q 3657:. 3654:n 3652:A 3644:n 3642:S 3634:. 3628:4 3625:A 3617:. 3611:k 3597:2 3591:n 3571:) 3568:k 3565:( 3557:n 3539:k 3518:) 3515:k 3512:( 3504:n 3485:. 3456:k 3436:) 3433:k 3430:( 3422:n 3386:G 3383:= 3378:) 3375:1 3372:( 3368:G 3347:G 3323:α 3299:} 3296:e 3293:{ 3290:= 3285:) 3279:( 3275:G 3257:N 3253:n 3239:} 3236:e 3233:{ 3225:) 3222:n 3219:( 3215:G 3201:n 3191:N 3187:n 3173:} 3170:e 3167:{ 3164:= 3159:) 3156:n 3153:( 3149:G 3135:G 3115:G 3102:e 3082:G 3054:G 3030:) 3026:Z 3022:, 3019:G 3016:( 3011:1 3007:H 2980:G 2929:] 2926:G 2923:, 2920:G 2917:[ 2913:/ 2909:G 2903:G 2877:G 2850:F 2847:= 2844:f 2824:H 2812:G 2808:: 2805:F 2785:H 2779:G 2776:: 2773:f 2753:H 2733:H 2713:G 2667:G 2660:G 2657:: 2625:G 2598:G 2574:G 2554:G 2530:] 2527:G 2524:, 2521:G 2518:[ 2514:/ 2510:G 2487:N 2481:] 2478:G 2475:, 2472:G 2469:[ 2449:N 2445:/ 2441:G 2418:G 2367:] 2364:G 2361:, 2356:1 2350:n 2346:G 2342:[ 2334:n 2330:G 2296:G 2293:= 2288:) 2285:0 2282:( 2278:G 2269:) 2266:1 2263:( 2259:G 2250:) 2247:2 2244:( 2240:G 2196:, 2191:) 2188:3 2185:( 2181:G 2177:, 2172:) 2169:2 2166:( 2162:G 2137:N 2130:n 2126:] 2121:) 2118:1 2112:n 2109:( 2105:G 2101:, 2096:) 2093:1 2087:n 2084:( 2080:G 2076:[ 2068:) 2065:n 2062:( 2058:G 2036:G 2028:) 2025:0 2022:( 2018:G 1995:k 1991:g 1987:2 1984:g 1981:1 1978:g 1974:g 1970:g 1963:G 1955:G 1951:H 1947:G 1922:] 1919:H 1916:, 1913:H 1910:[ 1904:) 1901:] 1898:G 1895:, 1892:G 1889:[ 1886:( 1883:f 1871:, 1859:] 1856:) 1851:n 1847:h 1843:( 1840:f 1837:, 1834:) 1829:n 1825:g 1821:( 1818:f 1815:[ 1809:] 1806:) 1801:1 1797:h 1793:( 1790:f 1787:, 1784:) 1779:1 1775:g 1771:( 1768:f 1765:[ 1762:= 1759:) 1756:] 1751:n 1747:h 1743:, 1738:n 1734:g 1730:[ 1724:] 1719:1 1715:h 1711:, 1706:1 1702:g 1698:[ 1695:( 1692:f 1679:H 1675:G 1671:f 1667:G 1653:] 1648:s 1643:n 1639:h 1635:, 1630:s 1625:n 1621:g 1617:[ 1611:] 1606:s 1601:1 1597:h 1593:, 1588:s 1583:1 1579:g 1575:[ 1572:= 1567:s 1563:) 1559:] 1554:n 1550:h 1546:, 1541:n 1537:g 1533:[ 1527:] 1522:1 1518:h 1514:, 1509:1 1505:g 1501:[ 1498:( 1488:G 1483:i 1479:h 1474:i 1470:g 1456:n 1430:] 1425:n 1421:h 1417:, 1412:n 1408:g 1404:[ 1398:] 1393:1 1389:h 1385:, 1380:1 1376:g 1372:[ 1349:] 1346:G 1343:, 1340:G 1337:[ 1320:G 1304:) 1301:1 1298:( 1294:G 1269:G 1244:] 1241:G 1238:, 1235:G 1232:[ 1211:d 1209:, 1207:c 1205:, 1203:b 1201:, 1199:a 1176:s 1172:x 1165:x 1155:G 1147:f 1143:G 1135:G 1131:H 1127:G 1106:. 1103:] 1100:) 1097:h 1094:( 1091:f 1088:, 1085:) 1082:g 1079:( 1076:f 1073:[ 1070:= 1067:) 1064:] 1061:h 1058:, 1055:g 1052:[ 1049:( 1046:f 1026:H 1020:G 1017:: 1014:f 989:, 986:s 966:g 940:1 933:s 929:g 926:s 923:= 918:s 914:g 893:s 890:g 885:1 878:s 874:= 869:s 865:g 844:, 841:] 836:s 832:h 828:, 823:s 819:g 815:[ 812:= 807:s 803:] 799:h 796:, 793:g 790:[ 769:, 766:] 763:g 760:, 757:h 754:[ 751:= 746:1 739:] 735:h 732:, 729:g 726:[ 713:G 709:h 705:g 701:s 694:G 690:e 686:h 682:g 668:] 665:h 662:, 659:g 656:[ 646:G 629:g 626:h 623:] 620:h 617:, 614:g 611:[ 608:= 605:h 602:g 582:] 579:h 576:, 573:g 570:[ 567:g 564:h 558:h 555:g 533:1 526:h 520:1 513:g 509:h 506:g 503:= 500:] 497:h 494:, 491:g 488:[ 465:] 462:h 459:, 456:g 453:[ 450:g 447:h 444:= 441:h 438:g 418:h 398:g 378:g 375:h 372:= 369:h 366:g 356:e 339:] 336:h 333:, 330:g 327:[ 307:h 304:g 299:1 292:h 286:1 279:g 275:= 272:] 269:h 266:, 263:g 260:[ 240:h 220:g 206:G 192:h 172:g 138:G 118:N 95:N 91:/ 87:G 20:)

Index

Derived group
mathematics
abstract algebra
group
subgroup
generated
commutators
smallest
normal subgroup
quotient group
abelian
if and only if
Commutator
commutator
identity element
conjugate
homomorphism
set
endomorphism
automorphism
free group
generated
natural number
functor
category of groups
fully characteristic subgroup
normal series
lower central series
perfect group
ordinal numbers

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