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Tensor product of fields

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1691: 50: 2245: 1446: 1844: 2052: 1033: 1686:{\displaystyle K\otimes L=K\otimes _{N}L=\mathbb {Q} /(x^{2}-2)\otimes _{\mathbb {Q} }\mathbb {Q} /(y^{2}-2)\cong \mathbb {Q} ({\sqrt {2}})/(z^{2}-2)\cong \mathbb {Q} ({\sqrt {2}})\otimes _{\mathbb {Q} }\mathbb {Q} ({\sqrt {2}})} 2044: 1920: 1410: 2810: 1724: 1970: 2668: 2578: 2314: 409: 1357: 1293: 720: 589: 2240:{\displaystyle K\otimes _{\tilde {N}}L=\mathbb {Q} /(x^{2}-2)\otimes _{\mathbb {Q} ({\sqrt {2}})}\mathbb {Q} /(y^{2}-2)\cong \mathbb {Q} ({\sqrt {2}})={\tilde {N}}\cong K\cong L} 1205: 916: 2507: 1438: 1108: 904: 793: 673: 505: 226: 2901: 2866: 2832: 2712: 2690: 2627: 2377: 2355: 2275: 1716: 752: 434: 367: 325: 157:. The idea behind the compositum is to make the smallest field containing two other fields. In order to formally define the compositum, one must first specify a 3096: 3040: 2046:. When one performs the tensor product over this better candidate for the largest common subfield we actually get a (rather trivial) field 1987: 3120: 1852: 2473: 1362: 1839:{\displaystyle K\otimes L\cong \mathbb {Q} ({\sqrt {2}})/(z^{2}-2)\cong \mathbb {Q} ({\sqrt {2}})\oplus \mathbb {Q} ({\sqrt {2}})} 2916: 2768: 796: 31: 1114:(intersection of all prime ideals) – and after taking the quotient by that one can speak of the product of all embeddings of 1925: 3019: 2991: 2967: 2636: 3135: 2515: 141:
The tensor product of two fields expresses in a single structure the different way to embed the two fields in a common
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are isomorphic but technically unequal fields with their (set theoretic) intersection being the prime field
441: 116: 1028:{\displaystyle \gamma (a\otimes b)=(\alpha (a)\otimes 1)\star (1\otimes \beta (b))=\alpha (a).\beta (b).} 1163: 2981: 2936: 2433: 1111: 112: 2479: 1415: 1080: 876: 765: 645: 477: 184: 2920: 104: 2884: 2849: 2815: 2695: 2673: 2610: 2360: 2338: 2258: 1699: 725: 417: 350: 308: 153:
First, one defines the notion of the compositum of fields. This construction occurs frequently in
3065: 1059: 639: 3009: 75: 3092: 3036: 2417: 1208: 870: 460: 248:. Either one starts in a situation where an ambient field is easy to identify (for example if 135: 3028: 1148:, the situation is particularly simple since the tensor product is of finite dimension as an 71: 1047: 1039: 849:(thus getting round the caveats about constructing a compositum field). Whenever one embeds 611: 595: 303: 3106: 3102: 3088: 2457: 2321: 1055: 158: 142: 2754:
as one sees by counting dimensions. The field factors are in 1–1 correspondence with the
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as 9, and observing that the splitting field does contain two (indeed three) copies of
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as a direct product of finitely many fields. Each such field is a representative of an
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The structure of the ring can be analysed by considering all ways of embedding both
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in each variable; and so defines a ring structure on the tensor product, making
619: 531: 124: 96: 269: 17: 2357:. One can prove this by calculating the dimension of the tensor product over 2278: 519: 119:. If no subfield is explicitly specified, the two fields must have the same 1718:-algebra. Furthermore this algebra is isomorphic to a direct sum of fields 2939:β€”tensor product of a field extension and a vector space over that field 3066:"A Brief Introduction to Classical and Adelic Algebraic Number Theory" 2603:, tensor products of fields are (implicitly, often) a basic tool. If 2383:, and is the compositum of two of them. That incidentally shows that 2039:{\displaystyle {\tilde {N}}=\mathbb {Q} ({\sqrt {2}})\cong K\cong L} 2923:
the radical is always {0}; therefore the Galois theory case is the
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The tensor product of two fields is sometimes a field, and often a
1915:{\displaystyle 1\mapsto (1,1),z\mapsto ({\sqrt {2}},-{\sqrt {2}})} 1050:
any prime ideal of the tensor product will give a homomorphism of
370: 530:. When the degrees are finite, injectivity is equivalent here to 436:. (This type of result can be verified, in general, by using the 522:. Naturally enough this isn't always the case, for example when 43: 2911:
This gives a general picture, and indeed a way of developing
1405:{\displaystyle \mathbb {Q} ({\sqrt {2}})\cong K\cong L\neq K} 228:
where the right-hand side denotes the extension generated by
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MathOverflow thread on the definition of linear disjointness
591:, as with the aforementioned extensions of the rationals. 542:
are linearly disjoint finite-degree extension fields over
2805:{\displaystyle K\otimes _{\mathbb {Q} }\mathbb {Q} _{p},} 260:), or one proves a result that allows one to place both 67: 1965:{\displaystyle {\tilde {N}}=\mathbb {Q} ({\sqrt {2}})} 2887: 2852: 2818: 2771: 2698: 2676: 2639: 2613: 2518: 2482: 2363: 2341: 2287: 2261: 2055: 1990: 1928: 1855: 1727: 1702: 1449: 1418: 1365: 1301: 1237: 1166: 1083: 919: 879: 768: 728: 681: 648: 552: 480: 420: 382: 353: 311: 187: 2663:{\displaystyle K\otimes _{\mathbb {Q} }\mathbb {R} } 827:. The construction here assumes the common subfield 2895: 2860: 2826: 2804: 2706: 2684: 2662: 2621: 2572: 2501: 2371: 2349: 2308: 2269: 2239: 2038: 1964: 1914: 1838: 1710: 1685: 1432: 1404: 1351: 1287: 1199: 1102: 1027: 898: 787: 746: 714: 667: 583: 499: 428: 403: 361: 319: 220: 134:of fields; In some cases, it can contain non-zero 2573:{\displaystyle T^{1/p}\otimes 1-1\otimes T^{1/p}} 638:To get a general theory, one needs to consider a 3029:"9.2 Decomposition of Tensor Products of Fields" 2873:, in 1–1 correspondence with the completions of 2390:An example leading to a non-zero nilpotent: let 1231:To give an explicit example consider the fields 3087:. Graduate Texts in Mathematics. Vol. 28. 2595:Classical theory of real and complex embeddings 1211:of (essentially distinct) field embeddings for 1077:In this way one can analyse the structure of 8: 2846:. This is a product of finite extensions of 2670:is always a product of fields isomorphic to 1070:in some field as extensions of (a copy of) 2889: 2888: 2886: 2854: 2853: 2851: 2820: 2819: 2817: 2793: 2789: 2788: 2781: 2780: 2779: 2770: 2762:, described in the classical literature. 2700: 2699: 2697: 2678: 2677: 2675: 2656: 2655: 2649: 2648: 2647: 2638: 2615: 2614: 2612: 2560: 2556: 2527: 2523: 2517: 2490: 2481: 2365: 2364: 2362: 2343: 2342: 2340: 2309:{\displaystyle K\otimes _{\mathbb {Q} }K} 2297: 2296: 2295: 2286: 2263: 2262: 2260: 2214: 2213: 2200: 2193: 2192: 2174: 2162: 2149: 2148: 2136: 2129: 2128: 2127: 2108: 2096: 2083: 2082: 2064: 2063: 2054: 2014: 2007: 2006: 1992: 1991: 1989: 1974:largest common subfield up to isomorphism 1952: 1945: 1944: 1930: 1929: 1927: 1902: 1889: 1854: 1826: 1819: 1818: 1805: 1798: 1797: 1779: 1767: 1748: 1741: 1740: 1726: 1704: 1703: 1701: 1673: 1666: 1665: 1659: 1658: 1657: 1643: 1636: 1635: 1617: 1605: 1586: 1579: 1578: 1560: 1548: 1535: 1534: 1528: 1527: 1526: 1507: 1495: 1482: 1481: 1469: 1448: 1426: 1425: 1417: 1374: 1367: 1366: 1364: 1334: 1322: 1309: 1308: 1300: 1270: 1258: 1245: 1244: 1236: 1189: 1177: 1165: 1091: 1082: 918: 887: 878: 776: 767: 727: 680: 656: 647: 572: 551: 488: 479: 422: 421: 419: 404:{\displaystyle K\otimes _{\mathbb {Q} }L} 392: 391: 390: 381: 355: 354: 352: 313: 312: 310: 186: 1352:{\displaystyle L=\mathbb {Q} /(y^{2}-2)} 1288:{\displaystyle K=\mathbb {Q} /(x^{2}-2)} 715:{\displaystyle (a\otimes b)(c\otimes d)} 302:. For example, if one adjoins √2 to the 2949: 1110:: there may in principle be a non-zero 584:{\displaystyle K.L\cong K\otimes _{N}L} 2760:pairs of complex conjugate embeddings 7: 1696:is not a field, but a 4-dimensional 758:). This formula is multilinear over 594:A significant case in the theory of 272:copies) in some large enough field. 2722:fields occur: in general there are 626:are linearly disjoint for distinct 74:in tone and meet Knowledge (XXG)'s 2927:one, of products of fields alone. 2474:purely inseparable field extension 1200:{\displaystyle (K\otimes _{N}L)/R} 25: 614:, the subfields generated by the 123:and the common subfield is their 1062:) and so provides embeddings of 48: 467:) when in this way the natural 275:In many cases one can identify 32:Tensor product (disambiguation) 2958:"Linearly-disjoint extensions" 2907:Consequences for Galois theory 2502:{\displaystyle L\otimes _{K}L} 2219: 2207: 2197: 2186: 2167: 2159: 2153: 2143: 2133: 2120: 2101: 2093: 2087: 2069: 2021: 2011: 1997: 1959: 1949: 1935: 1909: 1886: 1883: 1874: 1862: 1859: 1833: 1823: 1812: 1802: 1791: 1772: 1764: 1758: 1755: 1745: 1680: 1670: 1650: 1640: 1629: 1610: 1602: 1596: 1593: 1583: 1572: 1553: 1545: 1539: 1519: 1500: 1492: 1486: 1433:{\displaystyle N=\mathbb {Q} } 1381: 1371: 1346: 1327: 1319: 1313: 1282: 1263: 1255: 1249: 1186: 1167: 1103:{\displaystyle K\otimes _{N}L} 1019: 1013: 1004: 998: 989: 986: 980: 968: 962: 953: 947: 941: 935: 923: 899:{\displaystyle K\otimes _{N}L} 811:Analysis of the ring structure 788:{\displaystyle K\otimes _{N}L} 709: 697: 694: 682: 668:{\displaystyle K\otimes _{N}L} 500:{\displaystyle K\otimes _{N}L} 221:{\displaystyle K.L=k(K\cup L)} 215: 203: 1: 3050:Milne, J.S. (18 March 2017). 2587:th power one gets 0 by using 675:. One can define the product 618: th roots of unity for 27:Ring produced from two fields 3035:. Springer. pp. 85–87. 2919:). It can be shown that for 2917:Grothendieck's Galois theory 2896:{\displaystyle \mathbb {Q} } 2861:{\displaystyle \mathbb {Q} } 2827:{\displaystyle \mathbb {Q} } 2707:{\displaystyle \mathbb {C} } 2685:{\displaystyle \mathbb {R} } 2622:{\displaystyle \mathbb {Q} } 2583:is nilpotent: by taking its 2372:{\displaystyle \mathbb {Q} } 2350:{\displaystyle \mathbb {Q} } 2270:{\displaystyle \mathbb {Q} } 1711:{\displaystyle \mathbb {Q} } 1156:). One can then say that if 861:, say using embeddings Ξ± of 845:are subfields of some field 747:{\displaystyle ac\otimes bd} 429:{\displaystyle \mathbb {Q} } 362:{\displaystyle \mathbb {C} } 335:, it is true that the field 320:{\displaystyle \mathbb {Q} } 294:that is the intersection of 3015:Encyclopedia of Mathematics 2987:Encyclopedia of Mathematics 2963:Encyclopedia of Mathematics 1046:of the tensor product; and 823:in some field extension of 347:inside the complex numbers 3152: 3027:Kempf, George R. (2012) . 2915:(along lines exploited in 2765:This idea applies also to 2716:totally real number fields 2316:is the sum of (a copy of) 756:Tensor product of algebras 634:The tensor product as ring 256:are both subfields of the 177:. The compositum, denoted 36: 29: 2718:are those for which only 2436:: the point here is that 1972:should be considered the 1144:are finite extensions of 2251:For another example, if 1160:is the radical, one has 805:tensor product of fields 37:Not to be confused with 3064:Stein, William (2004). 3053:Algebraic Number Theory 2601:algebraic number theory 2448:is the field extension 1849:via the map induced by 1440:. Their tensor product 442:algebraic number theory 414:as a vector space over 290:, taken over the field 2897: 2877:for extensions of the 2862: 2828: 2806: 2708: 2686: 2664: 2623: 2574: 2503: 2373: 2351: 2310: 2271: 2241: 2040: 1966: 1916: 1840: 1712: 1687: 1434: 1406: 1353: 1289: 1201: 1152:-algebra (and thus an 1104: 1029: 900: 831:; but does not assume 789: 748: 716: 669: 585: 501: 430: 405: 363: 321: 240:field containing both 222: 3085:Commutative algebra I 2898: 2863: 2829: 2807: 2736:complex fields, with 2709: 2687: 2665: 2624: 2575: 2504: 2420:in the indeterminate 2374: 2352: 2311: 2272: 2242: 2041: 1984:via the isomorphisms 1967: 1917: 1841: 1713: 1688: 1435: 1407: 1354: 1290: 1202: 1105: 1030: 901: 790: 749: 717: 670: 586: 502: 431: 406: 364: 322: 223: 173:be two extensions of 3033:Algebraic Structures 2937:Extension of scalars 2921:separable extensions 2885: 2850: 2816: 2769: 2696: 2674: 2637: 2611: 2516: 2480: 2434:Separable polynomial 2387:= {0} in this case. 2361: 2339: 2285: 2259: 2053: 1988: 1926: 1853: 1725: 1700: 1447: 1416: 1363: 1299: 1235: 1164: 1081: 917: 877: 766: 726: 679: 646: 550: 478: 418: 380: 351: 309: 185: 149:Compositum of fields 68:improve this article 30:For other uses, see 3136:Field (mathematics) 3059:. p. 17. 3.07. 2607:is an extension of 2472:is an example of a 181:, is defined to be 2982:"Cyclotomic field" 2893: 2858: 2824: 2802: 2704: 2682: 2660: 2619: 2570: 2499: 2418:rational functions 2369: 2347: 2306: 2267: 2255:is generated over 2237: 2036: 1962: 1912: 1836: 1708: 1683: 1430: 1402: 1349: 1285: 1219:in some extension 1197: 1100: 1060:field of fractions 1025: 896: 869:, there results a 785: 744: 712: 665: 581: 497: 426: 401: 359: 317: 218: 136:nilpotent elements 3098:978-0-387-90089-6 3071:. pp. 140–2. 3042:978-3-322-80278-1 2629:of finite degree 2335:of degree 6 over 2222: 2205: 2141: 2072: 2019: 2000: 1957: 1938: 1907: 1894: 1831: 1810: 1753: 1678: 1648: 1591: 1379: 1209:equivalence class 871:ring homomorphism 596:cyclotomic fields 463:(over a subfield 461:linearly disjoint 93: 92: 76:quality standards 16:(Redirected from 3143: 3110: 3072: 3070: 3060: 3058: 3046: 3023: 2996: 2995: 2978: 2972: 2971: 2954: 2902: 2900: 2899: 2894: 2892: 2881:-adic metric on 2867: 2865: 2864: 2859: 2857: 2839:is the field of 2833: 2831: 2830: 2825: 2823: 2811: 2809: 2808: 2803: 2798: 2797: 2792: 2786: 2785: 2784: 2713: 2711: 2710: 2705: 2703: 2691: 2689: 2688: 2683: 2681: 2669: 2667: 2666: 2661: 2659: 2654: 2653: 2652: 2628: 2626: 2625: 2620: 2618: 2579: 2577: 2576: 2571: 2569: 2568: 2564: 2536: 2535: 2531: 2508: 2506: 2505: 2500: 2495: 2494: 2378: 2376: 2375: 2370: 2368: 2356: 2354: 2353: 2348: 2346: 2315: 2313: 2312: 2307: 2302: 2301: 2300: 2276: 2274: 2273: 2268: 2266: 2246: 2244: 2243: 2238: 2224: 2223: 2215: 2206: 2201: 2196: 2179: 2178: 2166: 2152: 2147: 2146: 2142: 2137: 2132: 2113: 2112: 2100: 2086: 2075: 2074: 2073: 2065: 2045: 2043: 2042: 2037: 2020: 2015: 2010: 2002: 2001: 1993: 1971: 1969: 1968: 1963: 1958: 1953: 1948: 1940: 1939: 1931: 1921: 1919: 1918: 1913: 1908: 1903: 1895: 1890: 1845: 1843: 1842: 1837: 1832: 1827: 1822: 1811: 1806: 1801: 1784: 1783: 1771: 1754: 1749: 1744: 1717: 1715: 1714: 1709: 1707: 1692: 1690: 1689: 1684: 1679: 1674: 1669: 1664: 1663: 1662: 1649: 1644: 1639: 1622: 1621: 1609: 1592: 1587: 1582: 1565: 1564: 1552: 1538: 1533: 1532: 1531: 1512: 1511: 1499: 1485: 1474: 1473: 1439: 1437: 1436: 1431: 1429: 1411: 1409: 1408: 1403: 1380: 1375: 1370: 1358: 1356: 1355: 1350: 1339: 1338: 1326: 1312: 1294: 1292: 1291: 1286: 1275: 1274: 1262: 1248: 1206: 1204: 1203: 1198: 1193: 1182: 1181: 1109: 1107: 1106: 1101: 1096: 1095: 1054:-algebras to an 1034: 1032: 1031: 1026: 905: 903: 902: 897: 892: 891: 857:in such a field 794: 792: 791: 786: 781: 780: 753: 751: 750: 745: 721: 719: 718: 713: 674: 672: 671: 666: 661: 660: 612:composite number 598:is that for the 590: 588: 587: 582: 577: 576: 506: 504: 503: 498: 493: 492: 435: 433: 432: 427: 425: 410: 408: 407: 402: 397: 396: 395: 368: 366: 365: 360: 358: 331:, and √3 to get 326: 324: 323: 318: 316: 227: 225: 224: 219: 88: 85: 79: 52: 51: 44: 21: 3151: 3150: 3146: 3145: 3144: 3142: 3141: 3140: 3126: 3125: 3117: 3099: 3089:Springer-Verlag 3075: 3068: 3063: 3056: 3049: 3043: 3026: 3008: 3005: 3000: 2999: 2980: 2979: 2975: 2956: 2955: 2951: 2946: 2933: 2909: 2883: 2882: 2872: 2848: 2847: 2838: 2814: 2813: 2787: 2775: 2767: 2766: 2756:real embeddings 2749: 2743: + 2 2742: 2735: 2728: 2694: 2693: 2672: 2671: 2643: 2635: 2634: 2609: 2608: 2597: 2552: 2519: 2514: 2513: 2486: 2478: 2477: 2458:splitting field 2444:separable). If 2359: 2358: 2337: 2336: 2322:splitting field 2291: 2283: 2282: 2257: 2256: 2170: 2123: 2104: 2059: 2051: 2050: 1986: 1985: 1924: 1923: 1851: 1850: 1775: 1723: 1722: 1698: 1697: 1653: 1613: 1556: 1522: 1503: 1465: 1445: 1444: 1414: 1413: 1361: 1360: 1330: 1297: 1296: 1266: 1233: 1232: 1229: 1173: 1162: 1161: 1087: 1079: 1078: 1056:integral domain 1042:of Ξ³ will be a 915: 914: 883: 875: 874: 813: 772: 764: 763: 724: 723: 677: 676: 652: 644: 643: 636: 568: 548: 547: 484: 476: 475: 471:-linear map of 416: 415: 386: 378: 377: 349: 348: 307: 306: 258:complex numbers 236:. This assumes 183: 182: 165:be a field and 159:tower of fields 151: 143:extension field 89: 83: 80: 65: 53: 49: 42: 35: 28: 23: 22: 15: 12: 11: 5: 3149: 3147: 3139: 3138: 3128: 3127: 3124: 3123: 3116: 3115:External links 3113: 3112: 3111: 3097: 3081:Samuel, Pierre 3077:Zariski, Oscar 3073: 3061: 3047: 3041: 3024: 3004: 3001: 2998: 2997: 2973: 2948: 2947: 2945: 2942: 2941: 2940: 2932: 2929: 2908: 2905: 2891: 2868: 2856: 2834: 2822: 2801: 2796: 2791: 2783: 2778: 2774: 2747: 2740: 2733: 2726: 2702: 2680: 2658: 2651: 2646: 2642: 2617: 2596: 2593: 2581: 2580: 2567: 2563: 2559: 2555: 2551: 2548: 2545: 2542: 2539: 2534: 2530: 2526: 2522: 2498: 2493: 2489: 2485: 2432:elements (see 2410: 2409: 2367: 2345: 2333: 2332: 2305: 2299: 2294: 2290: 2265: 2249: 2248: 2236: 2233: 2230: 2227: 2221: 2218: 2212: 2209: 2204: 2199: 2195: 2191: 2188: 2185: 2182: 2177: 2173: 2169: 2165: 2161: 2158: 2155: 2151: 2145: 2140: 2135: 2131: 2126: 2122: 2119: 2116: 2111: 2107: 2103: 2099: 2095: 2092: 2089: 2085: 2081: 2078: 2071: 2068: 2062: 2058: 2035: 2032: 2029: 2026: 2023: 2018: 2013: 2009: 2005: 1999: 1996: 1961: 1956: 1951: 1947: 1943: 1937: 1934: 1911: 1906: 1901: 1898: 1893: 1888: 1885: 1882: 1879: 1876: 1873: 1870: 1867: 1864: 1861: 1858: 1847: 1846: 1835: 1830: 1825: 1821: 1817: 1814: 1809: 1804: 1800: 1796: 1793: 1790: 1787: 1782: 1778: 1774: 1770: 1766: 1763: 1760: 1757: 1752: 1747: 1743: 1739: 1736: 1733: 1730: 1706: 1694: 1693: 1682: 1677: 1672: 1668: 1661: 1656: 1652: 1647: 1642: 1638: 1634: 1631: 1628: 1625: 1620: 1616: 1612: 1608: 1604: 1601: 1598: 1595: 1590: 1585: 1581: 1577: 1574: 1571: 1568: 1563: 1559: 1555: 1551: 1547: 1544: 1541: 1537: 1530: 1525: 1521: 1518: 1515: 1510: 1506: 1502: 1498: 1494: 1491: 1488: 1484: 1480: 1477: 1472: 1468: 1464: 1461: 1458: 1455: 1452: 1428: 1424: 1421: 1401: 1398: 1395: 1392: 1389: 1386: 1383: 1378: 1373: 1369: 1348: 1345: 1342: 1337: 1333: 1329: 1325: 1321: 1318: 1315: 1311: 1307: 1304: 1284: 1281: 1278: 1273: 1269: 1265: 1261: 1257: 1254: 1251: 1247: 1243: 1240: 1228: 1225: 1196: 1192: 1188: 1185: 1180: 1176: 1172: 1169: 1099: 1094: 1090: 1086: 1036: 1035: 1024: 1021: 1018: 1015: 1012: 1009: 1006: 1003: 1000: 997: 994: 991: 988: 985: 982: 979: 976: 973: 970: 967: 964: 961: 958: 955: 952: 949: 946: 943: 940: 937: 934: 931: 928: 925: 922: 895: 890: 886: 882: 812: 809: 784: 779: 775: 771: 743: 740: 737: 734: 731: 711: 708: 705: 702: 699: 696: 693: 690: 687: 684: 664: 659: 655: 651: 635: 632: 604:roots of unity 580: 575: 571: 567: 564: 561: 558: 555: 534:. Hence, when 508: 507: 496: 491: 487: 483: 424: 412: 411: 400: 394: 389: 385: 357: 315: 304:rational field 288:tensor product 217: 214: 211: 208: 205: 202: 199: 196: 193: 190: 150: 147: 132:direct product 125:prime subfield 121:characteristic 115:over a common 109:tensor product 101:tensor product 91: 90: 56: 54: 47: 26: 24: 18:Real embedding 14: 13: 10: 9: 6: 4: 3: 2: 3148: 3137: 3134: 3133: 3131: 3122: 3119: 3118: 3114: 3108: 3104: 3100: 3094: 3090: 3086: 3082: 3078: 3074: 3067: 3062: 3055: 3054: 3048: 3044: 3038: 3034: 3030: 3025: 3021: 3017: 3016: 3011: 3007: 3006: 3002: 2993: 2989: 2988: 2983: 2977: 2974: 2969: 2965: 2964: 2959: 2953: 2950: 2943: 2938: 2935: 2934: 2930: 2928: 2926: 2922: 2918: 2914: 2913:Galois theory 2906: 2904: 2880: 2876: 2871: 2845: 2844:-adic numbers 2843: 2837: 2799: 2794: 2776: 2772: 2763: 2761: 2757: 2753: 2746: 2739: 2732: 2725: 2721: 2717: 2644: 2640: 2632: 2606: 2602: 2594: 2592: 2590: 2586: 2565: 2561: 2557: 2553: 2549: 2546: 2543: 2540: 2537: 2532: 2528: 2524: 2520: 2512: 2511: 2510: 2496: 2491: 2487: 2483: 2475: 2471: 2467: 2463: 2459: 2455: 2451: 2447: 2443: 2439: 2435: 2431: 2427: 2423: 2419: 2416:the field of 2415: 2408: 2404: 2400: 2396: 2393: 2392: 2391: 2388: 2386: 2382: 2330: 2327: 2326: 2325: 2323: 2319: 2303: 2292: 2288: 2280: 2254: 2234: 2231: 2228: 2225: 2216: 2210: 2202: 2189: 2183: 2180: 2175: 2171: 2163: 2156: 2138: 2124: 2117: 2114: 2109: 2105: 2097: 2090: 2079: 2076: 2066: 2060: 2056: 2049: 2048: 2047: 2033: 2030: 2027: 2024: 2016: 2003: 1994: 1983: 1979: 1975: 1954: 1941: 1932: 1904: 1899: 1896: 1891: 1880: 1877: 1871: 1868: 1865: 1856: 1828: 1815: 1807: 1794: 1788: 1785: 1780: 1776: 1768: 1761: 1750: 1737: 1734: 1731: 1728: 1721: 1720: 1719: 1675: 1654: 1645: 1632: 1626: 1623: 1618: 1614: 1606: 1599: 1588: 1575: 1569: 1566: 1561: 1557: 1549: 1542: 1523: 1516: 1513: 1508: 1504: 1496: 1489: 1478: 1475: 1470: 1466: 1462: 1459: 1456: 1453: 1450: 1443: 1442: 1441: 1422: 1419: 1399: 1396: 1393: 1390: 1387: 1384: 1376: 1343: 1340: 1335: 1331: 1323: 1316: 1305: 1302: 1279: 1276: 1271: 1267: 1259: 1252: 1241: 1238: 1226: 1224: 1222: 1218: 1214: 1210: 1194: 1190: 1183: 1178: 1174: 1170: 1159: 1155: 1154:Artinian ring 1151: 1147: 1143: 1139: 1134: 1132: 1129: 1125: 1121: 1117: 1113: 1097: 1092: 1088: 1084: 1075: 1073: 1069: 1065: 1061: 1057: 1053: 1049: 1045: 1041: 1022: 1016: 1010: 1007: 1001: 995: 992: 983: 977: 974: 971: 965: 959: 956: 950: 944: 938: 932: 929: 926: 920: 913: 912: 911: 909: 893: 888: 884: 880: 872: 868: 864: 860: 856: 852: 848: 844: 840: 836: 835: 830: 826: 822: 818: 810: 808: 806: 803:, called the 802: 800: 782: 777: 773: 769: 761: 757: 741: 738: 735: 732: 729: 706: 703: 700: 691: 688: 685: 662: 657: 653: 649: 642:structure on 641: 633: 631: 629: 625: 621: 617: 613: 609: 605: 601: 597: 592: 578: 573: 569: 565: 562: 559: 556: 553: 545: 541: 537: 533: 529: 525: 521: 517: 513: 494: 489: 485: 481: 474: 473: 472: 470: 466: 462: 458: 454: 450: 445: 443: 439: 398: 387: 383: 376: 375: 374: 373:isomorphism) 372: 346: 342: 338: 334: 330: 305: 301: 297: 293: 289: 286: 282: 278: 273: 271: 267: 263: 259: 255: 251: 247: 243: 239: 235: 231: 212: 209: 206: 200: 197: 194: 191: 188: 180: 176: 172: 168: 164: 160: 156: 148: 146: 144: 139: 137: 133: 128: 126: 122: 118: 114: 110: 106: 102: 98: 87: 77: 73: 69: 63: 62: 59:reads like a 57:This article 55: 46: 45: 40: 33: 19: 3084: 3052: 3032: 3013: 3010:"Compositum" 2985: 2976: 2961: 2952: 2924: 2910: 2878: 2874: 2869: 2841: 2835: 2764: 2759: 2755: 2751: 2744: 2737: 2730: 2723: 2630: 2604: 2598: 2591:-linearity. 2588: 2584: 2582: 2509:the element 2469: 2465: 2461: 2453: 2449: 2445: 2441: 2437: 2429: 2426:finite field 2421: 2413: 2411: 2406: 2402: 2398: 2394: 2389: 2384: 2380: 2334: 2328: 2317: 2252: 2250: 1981: 1977: 1973: 1848: 1695: 1230: 1220: 1216: 1212: 1157: 1149: 1145: 1141: 1137: 1135: 1130: 1127: 1123: 1119: 1115: 1076: 1071: 1067: 1063: 1051: 1037: 910:defined by: 907: 866: 862: 858: 854: 850: 846: 842: 838: 832: 828: 824: 820: 816: 814: 804: 798: 797:commutative 759: 637: 627: 623: 620:prime powers 615: 607: 599: 593: 543: 539: 535: 527: 523: 515: 511: 509: 468: 464: 456: 452: 448: 446: 438:ramification 413: 344: 340: 339:obtained as 336: 332: 328: 299: 295: 291: 285:vector space 280: 276: 274: 265: 261: 253: 249: 245: 241: 237: 233: 229: 178: 174: 170: 166: 162: 155:field theory 152: 140: 129: 100: 94: 81: 58: 39:Tensor field 2281:of 2, then 1122:in various 1044:prime ideal 532:bijectivity 97:mathematics 84:August 2021 70:to make it 3003:References 2925:semisimple 1922:. Morally 1359:. Clearly 1112:nilradical 1058:(inside a 1048:conversely 447:Subfields 440:theory of 270:isomorphic 3083:(1975) . 3020:EMS Press 2992:EMS Press 2968:EMS Press 2777:⊗ 2729:real and 2645:⊗ 2550:⊗ 2544:− 2538:⊗ 2488:⊗ 2424:over the 2293:⊗ 2279:cube root 2232:≅ 2226:≅ 2220:~ 2190:≅ 2181:− 2125:⊗ 2115:− 2070:~ 2061:⊗ 2031:≅ 2025:≅ 1998:~ 1936:~ 1900:− 1884:↦ 1860:↦ 1816:⊕ 1795:≅ 1786:− 1738:≅ 1732:⊗ 1655:⊗ 1633:≅ 1624:− 1576:≅ 1567:− 1524:⊗ 1514:− 1467:⊗ 1454:⊗ 1397:≠ 1391:≅ 1385:≅ 1341:− 1277:− 1175:⊗ 1089:⊗ 1011:β 996:α 978:β 975:⊗ 966:⋆ 957:⊗ 945:α 930:⊗ 921:γ 885:⊗ 865:and Ξ² of 774:⊗ 736:⊗ 704:⊗ 689:⊗ 654:⊗ 622:dividing 570:⊗ 563:≅ 520:injective 486:⊗ 388:⊗ 210:∪ 107:is their 3130:Category 2931:See also 2320:, and a 1227:Examples 1136:In case 834:a priori 801:-algebra 117:subfield 113:algebras 61:textbook 3107:0090581 3022:, 2001 2994:, 2001 2970:, 2001 2464:) then 2456:) (the 2277:by the 873:Ξ³ from 795:into a 327:to get 103:of two 72:neutral 66:Please 3105:  3095:  3039:  2812:where 2758:, and 2714:. The 1040:kernel 722:to be 606:, for 161:. Let 105:fields 99:, the 3069:(PDF) 3057:(PDF) 2944:Notes 2476:. In 2428:with 2412:with 906:into 837:that 754:(see 371:up to 283:as a 3093:ISBN 3037:ISBN 2720:real 2401:) = 2331:βˆ’ 2, 1980:and 1295:and 1215:and 1140:and 1128:over 1118:and 1066:and 1038:The 853:and 841:and 819:and 640:ring 538:and 459:are 451:and 369:is ( 298:and 268:(as 264:and 252:and 244:and 238:some 232:and 169:and 2692:or 2599:In 2460:of 2442:not 2440:is 2324:of 1976:of 602:th 518:is 510:to 455:of 444:.) 179:K.L 111:as 95:In 3132:: 3103:MR 3101:. 3091:. 3079:; 3031:. 3018:, 3012:, 2990:, 2984:, 2966:, 2960:, 2903:. 2750:= 2633:, 2405:βˆ’ 1223:. 1133:. 1126:, 1074:. 807:. 630:. 610:a 546:, 526:= 145:. 138:. 127:. 3109:. 3045:. 2890:Q 2879:p 2875:K 2870:p 2855:Q 2842:p 2836:p 2821:Q 2800:, 2795:p 2790:Q 2782:Q 2773:K 2752:n 2748:2 2745:r 2741:1 2738:r 2734:2 2731:r 2727:1 2724:r 2701:C 2679:R 2657:R 2650:Q 2641:K 2631:n 2616:Q 2605:K 2589:K 2585:p 2566:p 2562:/ 2558:1 2554:T 2547:1 2541:1 2533:p 2529:/ 2525:1 2521:T 2497:L 2492:K 2484:L 2470:K 2468:/ 2466:L 2462:P 2454:T 2452:( 2450:K 2446:L 2438:P 2430:p 2422:T 2414:K 2407:T 2403:X 2399:X 2397:( 2395:P 2385:R 2381:K 2366:Q 2344:Q 2329:X 2318:K 2304:K 2298:Q 2289:K 2264:Q 2253:K 2247:. 2235:L 2229:K 2217:N 2211:= 2208:) 2203:2 2198:( 2194:Q 2187:) 2184:2 2176:2 2172:y 2168:( 2164:/ 2160:] 2157:y 2154:[ 2150:Q 2144:) 2139:2 2134:( 2130:Q 2121:) 2118:2 2110:2 2106:x 2102:( 2098:/ 2094:] 2091:x 2088:[ 2084:Q 2080:= 2077:L 2067:N 2057:K 2034:L 2028:K 2022:) 2017:2 2012:( 2008:Q 2004:= 1995:N 1982:L 1978:K 1960:) 1955:2 1950:( 1946:Q 1942:= 1933:N 1910:) 1905:2 1897:, 1892:2 1887:( 1881:z 1878:, 1875:) 1872:1 1869:, 1866:1 1863:( 1857:1 1834:) 1829:2 1824:( 1820:Q 1813:) 1808:2 1803:( 1799:Q 1792:) 1789:2 1781:2 1777:z 1773:( 1769:/ 1765:] 1762:z 1759:[ 1756:) 1751:2 1746:( 1742:Q 1735:L 1729:K 1705:Q 1681:) 1676:2 1671:( 1667:Q 1660:Q 1651:) 1646:2 1641:( 1637:Q 1630:) 1627:2 1619:2 1615:z 1611:( 1607:/ 1603:] 1600:z 1597:[ 1594:) 1589:2 1584:( 1580:Q 1573:) 1570:2 1562:2 1558:y 1554:( 1550:/ 1546:] 1543:y 1540:[ 1536:Q 1529:Q 1520:) 1517:2 1509:2 1505:x 1501:( 1497:/ 1493:] 1490:x 1487:[ 1483:Q 1479:= 1476:L 1471:N 1463:K 1460:= 1457:L 1451:K 1427:Q 1423:= 1420:N 1400:K 1394:L 1388:K 1382:) 1377:2 1372:( 1368:Q 1347:) 1344:2 1336:2 1332:y 1328:( 1324:/ 1320:] 1317:y 1314:[ 1310:Q 1306:= 1303:L 1283:) 1280:2 1272:2 1268:x 1264:( 1260:/ 1256:] 1253:x 1250:[ 1246:Q 1242:= 1239:K 1221:M 1217:L 1213:K 1195:R 1191:/ 1187:) 1184:L 1179:N 1171:K 1168:( 1158:R 1150:N 1146:N 1142:L 1138:K 1131:N 1124:M 1120:L 1116:K 1098:L 1093:N 1085:K 1072:N 1068:L 1064:K 1052:N 1023:. 1020:) 1017:b 1014:( 1008:. 1005:) 1002:a 999:( 993:= 990:) 987:) 984:b 981:( 972:1 969:( 963:) 960:1 954:) 951:a 948:( 942:( 939:= 936:) 933:b 927:a 924:( 908:M 894:L 889:N 881:K 867:L 863:K 859:M 855:L 851:K 847:M 843:L 839:K 829:N 825:N 821:L 817:K 799:N 783:L 778:N 770:K 760:N 742:d 739:b 733:c 730:a 710:) 707:d 701:c 698:( 695:) 692:b 686:a 683:( 663:L 658:N 650:K 628:p 624:n 616:p 608:n 600:n 579:L 574:N 566:K 560:L 557:. 554:K 544:N 540:L 536:K 528:L 524:K 516:L 514:. 512:K 495:L 490:N 482:K 469:N 465:N 457:M 453:L 449:K 423:Q 399:L 393:Q 384:K 356:C 345:L 343:. 341:K 337:M 333:L 329:K 314:Q 300:L 296:K 292:N 281:L 279:. 277:K 266:L 262:K 254:L 250:K 246:L 242:K 234:L 230:K 216:) 213:L 207:K 204:( 201:k 198:= 195:L 192:. 189:K 175:k 171:K 167:L 163:k 86:) 82:( 78:. 64:. 41:. 34:. 20:)

Index

Real embedding
Tensor product (disambiguation)
Tensor field
textbook
improve this article
neutral
quality standards
mathematics
fields
tensor product
algebras
subfield
characteristic
prime subfield
direct product
nilpotent elements
extension field
field theory
tower of fields
complex numbers
isomorphic
vector space
tensor product
rational field
up to
ramification
algebraic number theory
linearly disjoint
injective
bijectivity

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