Knowledge

Cohen–Macaulay ring

Source 📝

2272: 1852: 1550: 1122:(Kawamata log terminal) singularities; in characteristic zero, these are rational singularities and hence are Cohen–Macaulay, One successful analog of rational singularities in positive characteristic is the notion of 2105: 2503: 2073: 311: 245: 1228: 455: 570: 2868: 2796: 1656: 3410:
Matsumura (1989), Theorem 23.5.; NB: although the reference is somehow vague on whether a ring there is assumed to be local or not, the proof there does not need the ring to be local.
1452:
are Cohen–Macaulay if and only if they have no embedded primes. The singularities present in Cohen–Macaulay curves can be classified completely by looking at the plane curve case.
1388: 1427: 636: 607: 519: 1597: 1977: 1940: 728: 658: 3058:) (the coordinate ring of the union of a line and a plane) is reduced, but not equidimensional, and hence not Cohen–Macaulay. Taking the quotient by the non-zero-divisor 175: 1709: 1450: 1351: 1736: 1683: 1398:
Cohen–Macaulay curves are a special case of Cohen–Macaulay schemes, but are useful for compactifying moduli spaces of curves where the boundary of the smooth locus
930: 857: 1875: 1756: 1617: 1325: 786: 690: 478: 387: 363: 343: 2952:
generated by a number of elements equal to its height is unmixed. A Noetherian ring is Cohen–Macaulay if and only if the unmixedness theorem holds for it.
1072:=0, is a 1-dimensional domain which is Gorenstein, and hence Cohen–Macaulay, but not regular. This ring can also be described as the coordinate ring of the 1764: 3097:) (the coordinate ring of the union of two planes meeting in a point) is reduced and equidimensional, but not Cohen–Macaulay. To prove that, one can use 3559: 1466: 3718: 3118: 1460:
Using the criterion, there are easy examples of non-Cohen–Macaulay curves from constructing curves with embedded points. For example, the scheme
55:
is Cohen–Macaulay exactly when it is a finitely generated free module over a regular local subring. Cohen–Macaulay rings play a central role in
2955:
The unmixed theorem applies in particular to the zero ideal (an ideal generated by zero elements) and thus it says a Cohen–Macaulay ring is an
3255: 3978: 576:
unless we define zero modules as Cohen-Macaulay. So we define zero modules as Cohen-Macaulay modules in this definition.) Now, to define
2267:{\displaystyle {\frac {\mathbb {C} }{(y-x^{2})}}\otimes _{\mathbb {C} }{\frac {\mathbb {C} }{(y)}}\cong {\frac {\mathbb {C} }{(x^{2})}}} 1429:
is of Cohen–Macaulay curves. There is a useful criterion for deciding whether or not curves are Cohen–Macaulay. Schemes of dimension
3177:
for Gorenstein or Cohen–Macaulay schemes retain some of the simplicity of what happens for regular schemes or smooth varieties.
2447: 2013: 460:
The above definition was for a Noetherian local rings. But we can expand the definition for a more general Noetherian ring: If
250: 3889: 3816: 3730: 3693: 3652: 3537: 184: 1162: 2878: 1293: 400: 527: 2818: 2746: 3859: 3775: 3479: 2799: 314: 3710: 3669: 1626: 2999:) (the coordinate ring of a line with an embedded point) is not Cohen–Macaulay. This follows, for example, by 3632: 3617: 2959:; in fact, in the strong sense: there is no embedded component and each component has the same codimension. 3998: 2967: 953: 1356: 3993: 3612: 3607: 2326: 1401: 3881: 3843: 3800: 3759: 3677: 3529: 3174: 2683: 2322: 2084: 896: 112: 2079:
In general, that multiplicity is given as a length essentially characterizes Cohen–Macaulay ring; see
612: 583: 495: 2687: 2598: 2536:-module. Again, it follows that this freeness is independent of the choice of the polynomial subring 2302: 2087:, on the other hand, roughly characterizes a regular local ring as a local ring of multiplicity one. 1988: 1234: 144: 94: 1558: 3833: 3000: 1949: 1912: 1119: 1065: 937: 83: 63: 3248: 711: 641: 2376: 2293: 2277:
which is Cohen–Macaulay of length two, hence the intersection multiplicity is two, as expected.
1053:²) has dimension 0 and hence is Cohen–Macaulay, but it is not reduced and therefore not regular. 3602:
Cohen's paper was written when "local ring" meant what is now called a "Noetherian local ring".
979: 945: 3344:
smoothness here is somehow extraneous and is used in part to make sense of a proper component.
3301: 3973: 1658:, a curve with an embedded point can be constructed using the same technique: find the ideal 1115: 1034: 154: 1688: 1432: 1330: 3933: 3921: 3899: 3869: 3826: 3785: 3740: 3703: 3662: 3598: 3547: 3508: 3310: 2956: 2738: 1714: 1661: 1305: 1107: 990: 908: 2549:
A Noetherian local ring is Cohen–Macaulay if and only if its completion is Cohen–Macaulay.
8: 3837: 3122: 2594: 1886: 789: 573: 318: 71: 56: 3925: 3314: 2422:
have the same degree. It is striking that this property is independent of the choice of
801: 3911: 3586: 3496: 3166: 2963: 2934: 1860: 1741: 1602: 1310: 1134: 1073: 998: 903: 736: 705: 675: 463: 372: 348: 328: 118: 48: 40: 3885: 3855: 3812: 3792: 3771: 3747: 3726: 3689: 3648: 3578: 3533: 3328: 2099:
with a line tangent to it, the local ring at the intersection point is isomorphic to
1146: 796: 1847:{\displaystyle X={\text{Proj}}\left({\frac {\mathbb {C} }{I_{C}\cdot I_{x}}}\right)} 3847: 3804: 3763: 3681: 3640: 3568: 3488: 3318: 3146: 3134: 3098: 2911: 2686:. There is also a structure theorem for Cohen–Macaulay rings of codimension 2, the 2568: 2287: 1906: 36: 3296: 3929: 3895: 3865: 3822: 3781: 3736: 3722: 3699: 3658: 3636: 3594: 3543: 3504: 3158: 2731: 2670:). In geometric terms, this holds for a local ring of a subscheme of codimension 2396: 2369: 2285:
There is a remarkable characterization of Cohen–Macaulay rings, sometimes called
1266: 949: 892: 878: 731: 322: 134: 106: 3751: 3624: 3474: 3150: 2882: 2434: 2384: 860: 708:. This leads to various examples of Cohen–Macaulay rings, such as the integers 75: 59:: they form a very broad class, and yet they are well understood in many ways. 44: 3851: 3644: 1545:{\displaystyle X={\text{Spec}}\left({\frac {\mathbb {C} }{(x^{2},xy)}}\right)} 3987: 3808: 3767: 3582: 3332: 3170: 2372: 1980: 1942:, that is, an irreducible component of expected dimension. If the local ring 1111: 867: 522: 21: 3272: 3946: 874: 3951: 3685: 3963: 3554: 3162: 2354: 2342: 2318: 1619:-axis with an embedded point at the origin, which can be thought of as a 1103:=0, is a 1-dimensional domain which is Cohen–Macaulay but not Gorenstein. 885: 131: 28: 89:
For Noetherian local rings, there is the following chain of inclusions.
3968: 3590: 3500: 3323: 137: 52: 17: 3169:
scheme is Gorenstein. Thus the statements of duality theorems such as
2429:
Finally, there is a version of Miracle Flatness for graded rings. Let
3557:(1946), "On the structure and ideal theory of complete local rings", 3573: 3492: 3157:, is represented by a single sheaf. The stronger property of being 2096: 3916: 3109:
is a Cohen–Macaulay local ring of dimension at least 2, then Spec
3906:
Schwede, Karl; Tucker, Kevin (2012), "A survey of test ideals",
863:, for example a smooth variety over a field, is Cohen–Macaulay. 3880:, Cambridge Studies in Advanced Mathematics (2nd ed.), 3133:
One meaning of the Cohen–Macaulay condition can be seen in
700:
Noetherian rings of the following types are Cohen–Macaulay.
3721:. 3. Folge., vol. 2 (2nd ed.), Berlin, New York: 3528:, Cambridge Studies in Advanced Mathematics, vol. 39, 2280: 2498:{\displaystyle R=K\oplus R_{1}\oplus R_{2}\oplus \cdots .} 2068:{\displaystyle i(Z,V\cdot W,X)=\operatorname {length} (A)} 86:. All Cohen–Macaulay rings have the unmixedness property. 3629:
Commutative Algebra with a View toward Algebraic Geometry
2608:
is a quotient of a Cohen–Macaulay ring, then the locus {
306:{\displaystyle \mathrm {depth} (M)\leq \mathrm {dim} (M)} 3249:"Compactifying Locally Cohen–Macaulay Projective Curves" 1110:
over a field of characteristic zero are Cohen–Macaulay.
580:
Cohen-Macaulay modules for these rings, we require that
2095:
For a simple example, if we take the intersection of a
2644:) be a Noetherian local ring of embedding codimension 2821: 2749: 2450: 2108: 2016: 1952: 1915: 1863: 1767: 1744: 1717: 1691: 1664: 1629: 1605: 1561: 1469: 1435: 1404: 1359: 1333: 1313: 1261:. It follows, for example, that the affine cone Spec 1165: 911: 804: 739: 714: 678: 644: 615: 586: 530: 498: 466: 403: 375: 351: 331: 253: 240:{\displaystyle \mathrm {depth} (M)=\mathrm {dim} (M)} 187: 157: 3141:
is Cohen–Macaulay if the "dualizing complex", which
3015:, with degree 1 over points of the affine line Spec 1885:
Cohen–Macaulay schemes have a special relation with
1223:{\displaystyle R=\bigoplus _{j\geq 0}H^{0}(X,L^{j})} 3297:"Curve singularities of finite Cohen–Macaulay type" 2690:: they are all determinantal rings, defined by the 2556:is a Cohen–Macaulay ring, then the polynomial ring 450:{\displaystyle \mathrm {dim} (M)=\mathrm {dim} (R)} 2862: 2790: 2497: 2266: 2067: 1971: 1934: 1869: 1846: 1750: 1730: 1703: 1677: 1650: 1611: 1591: 1544: 1444: 1421: 1382: 1345: 1319: 1222: 1033:is Cohen−Macaulay. Similarly, coordinate rings of 924: 851: 780: 722: 684: 652: 630: 601: 565:{\displaystyle \mathrm {m} \in \mathrm {Supp} (M)} 564: 513: 472: 449: 381: 357: 337: 325:of a certain kind of modules). On the other hand, 305: 239: 169: 3560:Transactions of the American Mathematical Society 3219:Kollár & Mori (1998), Theorems 5.20 and 5.22. 2885:for rings that generalize this characterization.) 2863:{\displaystyle \operatorname {length} (R/Q)=e(Q)} 2791:{\displaystyle \operatorname {length} (R/Q)=e(Q)} 393:Cohen-Macaulay module is a Cohen-Macaulay module 3985: 3719:Ergebnisse der Mathematik und ihrer Grenzgebiete 2574:in the maximal ideal of a Noetherian local ring 1126:; again, such singularities are Cohen–Macaulay. 2966:(a ring in which the unmixed theorem holds for 2516:(with generators in various degrees) such that 2418:is Cohen–Macaulay if and only if all fibers of 2625:is Cohen–Macaulay } is an open subset of Spec 3910:, Berlin: Walter de Gruyter, pp. 39–99, 3905: 2593:The quotient of a Cohen–Macaulay ring by any 2364:A geometric reformulation is as follows. Let 2313:. Such a subring exists for any localization 866:Any 0-dimensional ring (or equivalently, any 3605: 2508:There is always a graded polynomial subring 936:is a Cohen–Macaulay algebra over a field of 3947:Examples of Cohen-Macaulay integral domains 3523: 2349:-module; it is also equivalent to say that 3797:Singularities of the Minimal Model Program 3756:Birational Geometry of Algebraic Varieties 3746: 3228:Schwede & Tucker (2012), Appendix C.1. 2889: 2333:is complete and contains a field, or when 480:is a commutative Noetherian ring, then an 82:), who proved the unmixedness theorem for 3915: 3875: 3572: 3322: 2682:is Cohen–Macaulay if and only if it is a 2305:as a module over some regular local ring 2230: 2190: 2165: 2113: 1901:closed subschemes of pure dimension. Let 1787: 1651:{\displaystyle C\subset \mathbb {P} ^{2}} 1638: 1489: 1299: 716: 3832: 3623: 3524:Bruns, Winfried; Herzog, Jürgen (1993), 3273:"Lemma 31.4.4 (0BXG)—The Stacks project" 2281:Miracle flatness or Hironaka's criterion 1623:. Given a smooth projective plane curve 1555:has the decomposition into prime ideals 1393: 1005:is equal to the "expected" codimension ( 963:be the quotient of a regular local ring 944:is a finite group (or more generally, a 672:if it is a Cohen-Macaulay module (as an 67: 3839:The Algebraic Theory of Modular Systems 3294: 3128: 2395:. By Noether normalization, there is a 2341:is Cohen–Macaulay if and only if it is 1114:over any field are Cohen–Macaulay. The 1099:, or its localization or completion at 369:if it is a Cohen-Macaulay module as an 3986: 3979:Wiles's proof of Fermat's Last Theorem 3791: 3709: 3668: 3353: 3023:≠ 0, but with degree 2 over the point 1880: 1118:makes prominent use of varieties with 3553: 2925:. (This is stronger than saying that 1909:of the scheme-theoretic intersection 1857:is a curve with an embedded point at 1233:is Cohen–Macaulay if and only if the 959:Any determinantal ring. That is, let 79: 3473: 3419:Matsumura (1989), Theorem 17.3.(ii). 3113:minus its closed point is connected. 2433:be a finitely generated commutative 1383:{\displaystyle {\mathcal {O}}_{X,x}} 3635:, vol. 150, Berlin, New York: 3192:Bruns & Herzog, from def. 2.1.1 3007:is finite over the polynomial ring 1327:is Cohen–Macaulay if at each point 521:is a Cohen-Macaulay module for all 13: 3477:(1964), "On unmixedness theorem", 3246: 2973: 1422:{\displaystyle {\mathcal {M}}_{g}} 1408: 1363: 1280:has dimension at least 2 (because 646: 622: 593: 549: 546: 543: 540: 532: 505: 434: 431: 428: 411: 408: 405: 345:is a module on itself, so we call 290: 287: 284: 267: 264: 261: 258: 255: 224: 221: 218: 201: 198: 195: 192: 189: 14: 4010: 3940: 3908:Progress in Commutative Algebra 2 3374:Eisenbud (1995), Corollary 18.17. 3365:Bruns & Herzog, Theorem A.22. 2721:), the following are equivalent: 2582:is Cohen–Macaulay if and only if 2528:is Cohen–Macaulay if and only if 1304:We say that a locally Noetherian 3952:Examples of Cohen-Macaulay rings 3446:Matsumura (1989), Theorem 17.11. 3437:Matsumura (1989), Exercise 24.2. 3383:Eisenbud (1995), Exercise 18.17. 3295:Wiegand, Roger (December 1991), 2910:is equal to the height of every 877:, for example any 1-dimensional 631:{\displaystyle R_{\mathrm {m} }} 602:{\displaystyle M_{\mathrm {m} }} 514:{\displaystyle M_{\mathrm {m} }} 3674:Introduction to Toric Varieties 3480:American Journal of Mathematics 3467: 3464:Eisenbud (1995), Theorem 18.12. 3458: 3455:Matsumura (1989), Theorem 17.6. 3449: 3440: 3431: 3428:Matsumura (1989), Theorem 17.9. 3422: 3413: 3404: 3401:Matsumura (1989), Theorem 17.7. 3395: 3392:Matsumura (1989), Theorem 17.5. 3386: 3377: 3368: 3359: 3347: 3338: 3261:from the original on 5 Mar 2020 3201:Eisenbud (1995), Theorem 18.18. 2879:Generalized Cohen–Macaulay ring 2080: 1711:and multiply it with the ideal 1455: 1294:Generalized Cohen–Macaulay ring 638:-module for each maximal ideal 3288: 3265: 3240: 3231: 3222: 3213: 3204: 3195: 3186: 2857: 2851: 2842: 2828: 2785: 2779: 2770: 2756: 2258: 2245: 2240: 2234: 2217: 2211: 2206: 2194: 2181: 2169: 2153: 2134: 2129: 2117: 2062: 2056: 2044: 2020: 1809: 1791: 1592:{\displaystyle (x)\cdot (x,y)} 1586: 1574: 1568: 1562: 1532: 1510: 1505: 1493: 1276:has dimension 1, but not when 1217: 1198: 846: 843: 811: 808: 775: 743: 559: 553: 444: 438: 421: 415: 300: 294: 277: 271: 234: 228: 211: 205: 74:for polynomial rings, and for 1: 3633:Graduate Texts in Mathematics 3517: 2944:is said to hold for the ring 2713:For a Noetherian local ring ( 2543: 1972:{\displaystyle V\times _{X}W} 1935:{\displaystyle V\times _{X}W} 859:. In geometric terms, every 125: 3876:Matsumura, Hideyuki (1989), 3137:theory. A variety or scheme 3125:need not be Cohen-Macaulay. 2968:integral closure of an ideal 2520:is finitely generated as an 1987:is Cohen-Macaulay, then the 948:whose identity component is 723:{\displaystyle \mathbb {Z} } 653:{\displaystyle \mathrm {m} } 64:Francis Sowerby Macaulay 51:. Under mild assumptions, a 7: 3957: 3613:Encyclopedia of Mathematics 3161:means that this sheaf is a 3066:gives the previous example. 2906:in height if the height of 2800:Hilbert–Samuel multiplicity 2337:is a complete domain. Then 2327:Noether normalization lemma 1153:. Then the section ring of 695: 315:Auslander–Buchsbaum formula 113:complete intersection rings 10: 4015: 3882:Cambridge University Press 3844:Cambridge University Press 3801:Cambridge University Press 3760:Cambridge University Press 3678:Princeton University Press 3530:Cambridge University Press 3175:Grothendieck local duality 3073:is a field, then the ring 3046:is a field, then the ring 2983:is a field, then the ring 2560:and the power series ring 2323:finitely generated algebra 2090: 2085:Multiplicity one criterion 2003:is given as the length of 1599:. Geometrically it is the 1141:≥ 1 over a field, and let 897:complete intersection ring 95:Universally catenary rings 15: 3645:10.1007/978-1-4612-5350-1 2811:For some parameter ideal 2737:(an ideal generated by a 2674:in a regular scheme. For 2301:be a local ring which is 1989:intersection multiplicity 1292:) is not zero). See also 1064:, or its localization or 997:. If the codimension (or 317:for the relation between 84:formal power series rings 3809:10.1017/CBO9781139547895 3768:10.1017/CBO9780511662560 3277:stacks.math.columbia.edu 3180: 1893:be a smooth variety and 1124:F-rational singularities 954:Hochster–Roberts theorem 664:. As in the local case, 16:Not to be confused with 3878:Commutative Ring Theory 3852:10.3792/chmm/1263317740 3165:. In particular, every 2890:The unmixedness theorem 1272:is Cohen–Macaulay when 1095:of the polynomial ring 1060:of the polynomial ring 1035:determinantal varieties 170:{\displaystyle M\neq 0} 3974:Gorenstein local rings 3606:V.I. Danilov (2001) , 3356:, Proposition 8.2. (b) 2864: 2792: 2499: 2329:; it also exists when 2268: 2069: 1973: 1936: 1871: 1848: 1752: 1732: 1705: 1704:{\displaystyle x\in C} 1679: 1652: 1613: 1593: 1546: 1446: 1445:{\displaystyle \leq 1} 1423: 1384: 1347: 1346:{\displaystyle x\in X} 1321: 1300:Cohen–Macaulay schemes 1249:) is zero for all 1 ≤ 1224: 1108:Rational singularities 946:linear algebraic group 926: 895:. In particular, any 853: 782: 724: 686: 654: 632: 603: 566: 515: 474: 451: 383: 359: 339: 307: 241: 171: 3686:10.1515/9781400882526 3608:"Cohen–Macaulay ring" 3237:Kollár (2013), (3.4). 3210:Fulton (1993), p. 89. 3103:connectedness theorem 2898:of a Noetherian ring 2865: 2793: 2688:Hilbert–Burch theorem 2564:] are Cohen–Macaulay. 2500: 2325:over a field, by the 2269: 2070: 1974: 1937: 1872: 1849: 1753: 1733: 1731:{\displaystyle I_{C}} 1706: 1680: 1678:{\displaystyle I_{x}} 1653: 1614: 1594: 1547: 1447: 1424: 1394:Cohen–Macaulay curves 1385: 1348: 1322: 1225: 1116:minimal model program 927: 925:{\displaystyle R^{G}} 854: 783: 725: 687: 655: 633: 604: 572:. (This is a kind of 567: 516: 490:Cohen–Macaulay module 475: 452: 384: 360: 340: 308: 247:(in general we have: 242: 179:Cohen-Macaulay module 172: 3526:Cohen–Macaulay Rings 3129:Grothendieck duality 3123:Cohen-Macaulay rings 2957:equidimensional ring 2819: 2747: 2739:system of parameters 2599:universally catenary 2590:) is Cohen–Macaulay. 2532:is free as a graded 2448: 2391:be the dimension of 2294:Hironaka's criterion 2106: 2014: 1950: 1913: 1861: 1765: 1742: 1715: 1689: 1662: 1627: 1603: 1559: 1467: 1433: 1402: 1357: 1331: 1311: 1257:−1 and all integers 1163: 1041:Some more examples: 909: 802: 737: 712: 692:-module on itself). 676: 642: 613: 584: 528: 496: 464: 401: 373: 349: 329: 251: 185: 155: 101:Cohen–Macaulay rings 3999:Commutative algebra 3926:2011arXiv1104.2000S 3715:Intersection theory 3315:1991ArM....29..339W 3302:Arkiv för Matematik 3039:) has dimension 2). 2942:unmixedness theorem 1887:intersection theory 1881:Intersection theory 1390:is Cohen–Macaulay. 1037:are Cohen-Macaulay. 670:Cohen-Macaulay ring 574:circular definition 367:Cohen-Macaulay ring 119:regular local rings 72:unmixedness theorem 62:They are named for 57:commutative algebra 33:Cohen–Macaulay ring 3994:Algebraic geometry 3324:10.1007/BF02384346 2964:quasi-unmixed ring 2860: 2788: 2727:is Cohen–Macaulay. 2495: 2303:finitely generated 2264: 2065: 1969: 1932: 1867: 1844: 1748: 1728: 1701: 1675: 1648: 1609: 1589: 1542: 1442: 1419: 1380: 1343: 1317: 1220: 1187: 1135:projective variety 1027:determinantal ring 922: 904:ring of invariants 884:Any 2-dimensional 873:Any 1-dimensional 852:{\displaystyle K]} 849: 778: 720: 706:regular local ring 682: 650: 628: 599: 562: 511: 470: 447: 379: 355: 335: 303: 237: 167: 145:finitely generated 70:), who proved the 49:equidimensionality 3891:978-0-521-36764-6 3818:978-1-107-03534-8 3732:978-3-540-62046-4 3695:978-0-691-00049-7 3654:978-0-387-94268-1 3539:978-0-521-41068-7 3027:= 0 (because the 2684:hypersurface ring 2383:(for example, an 2262: 2221: 2157: 1889:. Precisely, let 1870:{\displaystyle x} 1838: 1777: 1751:{\displaystyle C} 1612:{\displaystyle y} 1536: 1479: 1320:{\displaystyle X} 1172: 1147:ample line bundle 971:generated by the 797:power series ring 781:{\displaystyle K} 685:{\displaystyle R} 473:{\displaystyle R} 382:{\displaystyle R} 358:{\displaystyle R} 338:{\displaystyle R} 143:, a finite (i.e. 41:algebro-geometric 39:with some of the 4006: 3936: 3919: 3902: 3872: 3829: 3788: 3743: 3706: 3665: 3620: 3601: 3576: 3550: 3512: 3511: 3471: 3465: 3462: 3456: 3453: 3447: 3444: 3438: 3435: 3429: 3426: 3420: 3417: 3411: 3408: 3402: 3399: 3393: 3390: 3384: 3381: 3375: 3372: 3366: 3363: 3357: 3351: 3345: 3342: 3336: 3335: 3326: 3309:(1–2): 339–357, 3292: 3286: 3285: 3284: 3283: 3269: 3263: 3262: 3260: 3253: 3247:Honsen, Morten, 3244: 3238: 3235: 3229: 3226: 3220: 3217: 3211: 3208: 3202: 3199: 3193: 3190: 3147:derived category 3135:coherent duality 3001:Miracle Flatness 2912:associated prime 2869: 2867: 2866: 2861: 2838: 2797: 2795: 2794: 2789: 2766: 2706:matrix for some 2569:non-zero-divisor 2504: 2502: 2501: 2496: 2485: 2484: 2472: 2471: 2406:to affine space 2288:miracle flatness 2273: 2271: 2270: 2265: 2263: 2261: 2257: 2256: 2243: 2233: 2227: 2222: 2220: 2209: 2193: 2187: 2185: 2184: 2168: 2158: 2156: 2152: 2151: 2132: 2116: 2110: 2074: 2072: 2071: 2066: 1978: 1976: 1975: 1970: 1965: 1964: 1941: 1939: 1938: 1933: 1928: 1927: 1907:proper component 1876: 1874: 1873: 1868: 1853: 1851: 1850: 1845: 1843: 1839: 1837: 1836: 1835: 1823: 1822: 1812: 1790: 1784: 1778: 1775: 1757: 1755: 1754: 1749: 1737: 1735: 1734: 1729: 1727: 1726: 1710: 1708: 1707: 1702: 1684: 1682: 1681: 1676: 1674: 1673: 1657: 1655: 1654: 1649: 1647: 1646: 1641: 1618: 1616: 1615: 1610: 1598: 1596: 1595: 1590: 1551: 1549: 1548: 1543: 1541: 1537: 1535: 1522: 1521: 1508: 1492: 1486: 1480: 1477: 1451: 1449: 1448: 1443: 1428: 1426: 1425: 1420: 1418: 1417: 1412: 1411: 1389: 1387: 1386: 1381: 1379: 1378: 1367: 1366: 1352: 1350: 1349: 1344: 1326: 1324: 1323: 1318: 1229: 1227: 1226: 1221: 1216: 1215: 1197: 1196: 1186: 1029:. In that case, 931: 929: 928: 923: 921: 920: 858: 856: 855: 850: 842: 841: 823: 822: 787: 785: 784: 779: 774: 773: 755: 754: 729: 727: 726: 721: 719: 691: 689: 688: 683: 659: 657: 656: 651: 649: 637: 635: 634: 629: 627: 626: 625: 608: 606: 605: 600: 598: 597: 596: 571: 569: 568: 563: 552: 535: 520: 518: 517: 512: 510: 509: 508: 479: 477: 476: 471: 456: 454: 453: 448: 437: 414: 388: 386: 385: 380: 364: 362: 361: 356: 344: 342: 341: 336: 312: 310: 309: 304: 293: 270: 246: 244: 243: 238: 227: 204: 176: 174: 173: 168: 107:Gorenstein rings 47:, such as local 43:properties of a 37:commutative ring 4014: 4013: 4009: 4008: 4007: 4005: 4004: 4003: 3984: 3983: 3960: 3943: 3892: 3862: 3819: 3778: 3752:Mori, Shigefumi 3733: 3723:Springer-Verlag 3711:Fulton, William 3696: 3670:Fulton, William 3655: 3637:Springer-Verlag 3625:Eisenbud, David 3574:10.2307/1990313 3540: 3520: 3515: 3493:10.2307/2373158 3475:Chow, Wei Liang 3472: 3468: 3463: 3459: 3454: 3450: 3445: 3441: 3436: 3432: 3427: 3423: 3418: 3414: 3409: 3405: 3400: 3396: 3391: 3387: 3382: 3378: 3373: 3369: 3364: 3360: 3352: 3348: 3343: 3339: 3293: 3289: 3281: 3279: 3271: 3270: 3266: 3258: 3251: 3245: 3241: 3236: 3232: 3227: 3223: 3218: 3214: 3209: 3205: 3200: 3196: 3191: 3187: 3183: 3131: 2976: 2974:Counterexamples 2948:if every ideal 2935:equidimensional 2892: 2834: 2820: 2817: 2816: 2762: 2748: 2745: 2744: 2732:parameter ideal 2657: 2648:, meaning that 2624: 2546: 2480: 2476: 2467: 2463: 2449: 2446: 2445: 2397:finite morphism 2283: 2252: 2248: 2244: 2229: 2228: 2226: 2210: 2189: 2188: 2186: 2164: 2163: 2159: 2147: 2143: 2133: 2112: 2111: 2109: 2107: 2104: 2103: 2093: 2015: 2012: 2011: 1960: 1956: 1951: 1948: 1947: 1923: 1919: 1914: 1911: 1910: 1883: 1862: 1859: 1858: 1831: 1827: 1818: 1814: 1813: 1786: 1785: 1783: 1779: 1774: 1766: 1763: 1762: 1743: 1740: 1739: 1722: 1718: 1716: 1713: 1712: 1690: 1687: 1686: 1669: 1665: 1663: 1660: 1659: 1642: 1637: 1636: 1628: 1625: 1624: 1604: 1601: 1600: 1560: 1557: 1556: 1517: 1513: 1509: 1488: 1487: 1485: 1481: 1476: 1468: 1465: 1464: 1458: 1434: 1431: 1430: 1413: 1407: 1406: 1405: 1403: 1400: 1399: 1396: 1368: 1362: 1361: 1360: 1358: 1355: 1354: 1353:the local ring 1332: 1329: 1328: 1312: 1309: 1308: 1302: 1267:abelian variety 1211: 1207: 1192: 1188: 1176: 1164: 1161: 1160: 1112:Toric varieties 993:of elements of 952:). This is the 916: 912: 910: 907: 906: 893:Gorenstein ring 837: 833: 818: 814: 803: 800: 799: 769: 765: 750: 746: 738: 735: 734: 732:polynomial ring 715: 713: 710: 709: 698: 677: 674: 673: 645: 643: 640: 639: 621: 620: 616: 614: 611: 610: 592: 591: 587: 585: 582: 581: 539: 531: 529: 526: 525: 504: 503: 499: 497: 494: 493: 465: 462: 461: 427: 404: 402: 399: 398: 374: 371: 370: 350: 347: 346: 330: 327: 326: 283: 254: 252: 249: 248: 217: 188: 186: 183: 182: 156: 153: 152: 128: 76:Irvin Cohen 25: 12: 11: 5: 4012: 4002: 4001: 3996: 3982: 3981: 3976: 3971: 3966: 3959: 3956: 3955: 3954: 3949: 3942: 3941:External links 3939: 3938: 3937: 3903: 3890: 3873: 3860: 3834:Macaulay, F.S. 3830: 3817: 3789: 3776: 3744: 3731: 3707: 3694: 3666: 3653: 3621: 3603: 3551: 3538: 3519: 3516: 3514: 3513: 3466: 3457: 3448: 3439: 3430: 3421: 3412: 3403: 3394: 3385: 3376: 3367: 3358: 3346: 3337: 3287: 3264: 3239: 3230: 3221: 3212: 3203: 3194: 3184: 3182: 3179: 3130: 3127: 3115: 3114: 3067: 3040: 3031:-vector space 2975: 2972: 2937:; see below.) 2891: 2888: 2887: 2886: 2883:Buchsbaum ring 2874: 2873: 2872: 2871: 2859: 2856: 2853: 2850: 2847: 2844: 2841: 2837: 2833: 2830: 2827: 2824: 2809: 2808: 2807: 2787: 2784: 2781: 2778: 2775: 2772: 2769: 2765: 2761: 2758: 2755: 2752: 2728: 2711: 2698:minors of an ( 2653: 2630: 2620: 2602: 2591: 2565: 2550: 2545: 2542: 2524:-module. Then 2506: 2505: 2494: 2491: 2488: 2483: 2479: 2475: 2470: 2466: 2462: 2459: 2456: 2453: 2435:graded algebra 2385:affine variety 2282: 2279: 2275: 2274: 2260: 2255: 2251: 2247: 2242: 2239: 2236: 2232: 2225: 2219: 2216: 2213: 2208: 2205: 2202: 2199: 2196: 2192: 2183: 2180: 2177: 2174: 2171: 2167: 2162: 2155: 2150: 2146: 2142: 2139: 2136: 2131: 2128: 2125: 2122: 2119: 2115: 2092: 2089: 2077: 2076: 2064: 2061: 2058: 2055: 2052: 2049: 2046: 2043: 2040: 2037: 2034: 2031: 2028: 2025: 2022: 2019: 1968: 1963: 1959: 1955: 1931: 1926: 1922: 1918: 1882: 1879: 1866: 1855: 1854: 1842: 1834: 1830: 1826: 1821: 1817: 1811: 1808: 1805: 1802: 1799: 1796: 1793: 1789: 1782: 1773: 1770: 1747: 1725: 1721: 1700: 1697: 1694: 1685:of a point in 1672: 1668: 1645: 1640: 1635: 1632: 1608: 1588: 1585: 1582: 1579: 1576: 1573: 1570: 1567: 1564: 1553: 1552: 1540: 1534: 1531: 1528: 1525: 1520: 1516: 1512: 1507: 1504: 1501: 1498: 1495: 1491: 1484: 1475: 1472: 1457: 1454: 1441: 1438: 1416: 1410: 1395: 1392: 1377: 1374: 1371: 1365: 1342: 1339: 1336: 1316: 1301: 1298: 1231: 1230: 1219: 1214: 1210: 1206: 1203: 1200: 1195: 1191: 1185: 1182: 1179: 1175: 1171: 1168: 1105: 1104: 1089: 1054: 1039: 1038: 957: 938:characteristic 919: 915: 900: 889: 882: 871: 864: 861:regular scheme 848: 845: 840: 836: 832: 829: 826: 821: 817: 813: 810: 807: 777: 772: 768: 764: 761: 758: 753: 749: 745: 742: 718: 697: 694: 681: 648: 624: 619: 609:to be such an 595: 590: 561: 558: 555: 551: 548: 545: 542: 538: 534: 523:maximal ideals 507: 502: 469: 446: 443: 440: 436: 433: 430: 426: 423: 420: 417: 413: 410: 407: 378: 354: 334: 302: 299: 296: 292: 289: 286: 282: 279: 276: 273: 269: 266: 263: 260: 257: 236: 233: 230: 226: 223: 220: 216: 213: 210: 207: 203: 200: 197: 194: 191: 166: 163: 160: 127: 124: 123: 122: 45:smooth variety 9: 6: 4: 3: 2: 4011: 4000: 3997: 3995: 3992: 3991: 3989: 3980: 3977: 3975: 3972: 3970: 3967: 3965: 3962: 3961: 3953: 3950: 3948: 3945: 3944: 3935: 3931: 3927: 3923: 3918: 3913: 3909: 3904: 3901: 3897: 3893: 3887: 3883: 3879: 3874: 3871: 3867: 3863: 3861:1-4297-0441-1 3857: 3853: 3849: 3845: 3841: 3840: 3835: 3831: 3828: 3824: 3820: 3814: 3810: 3806: 3802: 3798: 3794: 3793:Kollár, János 3790: 3787: 3783: 3779: 3777:0-521-63277-3 3773: 3769: 3765: 3761: 3757: 3753: 3749: 3748:Kollár, János 3745: 3742: 3738: 3734: 3728: 3724: 3720: 3716: 3712: 3708: 3705: 3701: 3697: 3691: 3687: 3683: 3679: 3675: 3671: 3667: 3664: 3660: 3656: 3650: 3646: 3642: 3638: 3634: 3630: 3626: 3622: 3619: 3615: 3614: 3609: 3604: 3600: 3596: 3592: 3588: 3584: 3580: 3575: 3570: 3567:(1): 54–106, 3566: 3562: 3561: 3556: 3552: 3549: 3545: 3541: 3535: 3531: 3527: 3522: 3521: 3510: 3506: 3502: 3498: 3494: 3490: 3486: 3482: 3481: 3476: 3470: 3461: 3452: 3443: 3434: 3425: 3416: 3407: 3398: 3389: 3380: 3371: 3362: 3355: 3350: 3341: 3334: 3330: 3325: 3320: 3316: 3312: 3308: 3304: 3303: 3298: 3291: 3278: 3274: 3268: 3257: 3250: 3243: 3234: 3225: 3216: 3207: 3198: 3189: 3185: 3178: 3176: 3172: 3171:Serre duality 3168: 3164: 3160: 3156: 3152: 3148: 3144: 3140: 3136: 3126: 3124: 3120: 3119:Segre product 3112: 3108: 3104: 3100: 3096: 3092: 3088: 3084: 3080: 3076: 3072: 3068: 3065: 3061: 3057: 3053: 3049: 3045: 3041: 3038: 3034: 3030: 3026: 3022: 3018: 3014: 3010: 3006: 3002: 2998: 2994: 2990: 2986: 2982: 2978: 2977: 2971: 2969: 2965: 2960: 2958: 2953: 2951: 2947: 2943: 2938: 2936: 2932: 2928: 2924: 2920: 2916: 2913: 2909: 2905: 2901: 2897: 2884: 2880: 2876: 2875: 2854: 2848: 2845: 2839: 2835: 2831: 2825: 2822: 2814: 2810: 2805: 2801: 2798: := the 2782: 2776: 2773: 2767: 2763: 2759: 2753: 2750: 2743: 2742: 2740: 2736: 2733: 2729: 2726: 2723: 2722: 2720: 2716: 2712: 2709: 2705: 2701: 2697: 2693: 2689: 2685: 2681: 2677: 2673: 2669: 2665: 2661: 2656: 2651: 2647: 2643: 2639: 2635: 2631: 2628: 2623: 2619: 2615: 2611: 2607: 2603: 2600: 2596: 2592: 2589: 2585: 2581: 2577: 2573: 2570: 2566: 2563: 2559: 2555: 2551: 2548: 2547: 2541: 2539: 2535: 2531: 2527: 2523: 2519: 2515: 2511: 2492: 2489: 2486: 2481: 2477: 2473: 2468: 2464: 2460: 2457: 2454: 2451: 2444: 2443: 2442: 2440: 2437:over a field 2436: 2432: 2427: 2425: 2421: 2417: 2413: 2409: 2405: 2401: 2398: 2394: 2390: 2386: 2382: 2379:over a field 2378: 2374: 2373:affine scheme 2371: 2367: 2362: 2360: 2356: 2352: 2348: 2344: 2340: 2336: 2332: 2328: 2324: 2320: 2316: 2312: 2309:contained in 2308: 2304: 2300: 2296: 2295: 2290: 2289: 2278: 2253: 2249: 2237: 2223: 2214: 2203: 2200: 2197: 2178: 2175: 2172: 2160: 2148: 2144: 2140: 2137: 2126: 2123: 2120: 2102: 2101: 2100: 2098: 2088: 2086: 2082: 2059: 2053: 2050: 2047: 2041: 2038: 2035: 2032: 2029: 2026: 2023: 2017: 2010: 2009: 2008: 2006: 2002: 1998: 1994: 1990: 1986: 1982: 1981:generic point 1966: 1961: 1957: 1953: 1945: 1929: 1924: 1920: 1916: 1908: 1904: 1900: 1896: 1892: 1888: 1878: 1864: 1840: 1832: 1828: 1824: 1819: 1815: 1806: 1803: 1800: 1797: 1794: 1780: 1771: 1768: 1761: 1760: 1759: 1745: 1723: 1719: 1698: 1695: 1692: 1670: 1666: 1643: 1633: 1630: 1622: 1606: 1583: 1580: 1577: 1571: 1565: 1538: 1529: 1526: 1523: 1518: 1514: 1502: 1499: 1496: 1482: 1473: 1470: 1463: 1462: 1461: 1453: 1439: 1436: 1414: 1391: 1375: 1372: 1369: 1340: 1337: 1334: 1314: 1307: 1297: 1295: 1291: 1287: 1283: 1279: 1275: 1271: 1268: 1264: 1260: 1256: 1252: 1248: 1244: 1240: 1236: 1212: 1208: 1204: 1201: 1193: 1189: 1183: 1180: 1177: 1173: 1169: 1166: 1159: 1158: 1157: 1156: 1152: 1148: 1144: 1140: 1137:of dimension 1136: 1132: 1127: 1125: 1121: 1117: 1113: 1109: 1102: 1098: 1094: 1090: 1087: 1083: 1079: 1075: 1071: 1067: 1063: 1059: 1055: 1052: 1048: 1044: 1043: 1042: 1036: 1032: 1028: 1024: 1020: 1016: 1012: 1008: 1004: 1000: 996: 992: 989: 985: 981: 978: 974: 970: 967:by the ideal 966: 962: 958: 955: 951: 947: 943: 939: 935: 917: 913: 905: 901: 898: 894: 890: 887: 883: 880: 876: 872: 869: 868:Artinian ring 865: 862: 838: 834: 830: 827: 824: 819: 815: 805: 798: 794: 791: 770: 766: 762: 759: 756: 751: 747: 740: 733: 707: 703: 702: 701: 693: 679: 671: 667: 663: 617: 588: 579: 575: 556: 536: 524: 500: 491: 487: 483: 467: 458: 441: 424: 418: 396: 392: 376: 368: 352: 332: 324: 320: 316: 297: 280: 274: 231: 214: 208: 180: 164: 161: 158: 150: 146: 142: 139: 136: 133: 121: 120: 115: 114: 109: 108: 103: 102: 97: 96: 92: 91: 90: 87: 85: 81: 77: 73: 69: 65: 60: 58: 54: 50: 46: 42: 38: 34: 30: 23: 22:Cohen algebra 19: 3907: 3877: 3838: 3796: 3755: 3714: 3673: 3628: 3611: 3564: 3558: 3555:Cohen, I. S. 3525: 3484: 3478: 3469: 3460: 3451: 3442: 3433: 3424: 3415: 3406: 3397: 3388: 3379: 3370: 3361: 3349: 3340: 3306: 3300: 3290: 3280:, retrieved 3276: 3267: 3242: 3233: 3224: 3215: 3206: 3197: 3188: 3154: 3145:lies in the 3142: 3138: 3132: 3116: 3110: 3106: 3102: 3094: 3090: 3086: 3082: 3078: 3074: 3070: 3063: 3059: 3055: 3051: 3047: 3043: 3036: 3032: 3028: 3024: 3020: 3016: 3012: 3008: 3004: 2996: 2992: 2988: 2984: 2980: 2961: 2954: 2949: 2945: 2941: 2939: 2930: 2926: 2922: 2918: 2914: 2907: 2903: 2899: 2895: 2893: 2812: 2803: 2734: 2724: 2718: 2714: 2707: 2703: 2699: 2695: 2691: 2679: 2675: 2671: 2667: 2663: 2659: 2654: 2649: 2645: 2641: 2637: 2633: 2626: 2621: 2617: 2613: 2609: 2605: 2587: 2583: 2579: 2575: 2571: 2561: 2557: 2553: 2537: 2533: 2529: 2525: 2521: 2517: 2513: 2509: 2507: 2438: 2430: 2428: 2423: 2419: 2415: 2411: 2407: 2403: 2399: 2392: 2388: 2380: 2365: 2363: 2358: 2350: 2346: 2338: 2334: 2330: 2314: 2310: 2306: 2298: 2292: 2286: 2284: 2276: 2094: 2078: 2004: 2000: 1996: 1992: 1984: 1943: 1902: 1898: 1894: 1890: 1884: 1856: 1620: 1554: 1459: 1456:Non-examples 1397: 1303: 1289: 1285: 1281: 1277: 1273: 1269: 1262: 1258: 1254: 1250: 1246: 1242: 1238: 1232: 1154: 1150: 1142: 1138: 1130: 1128: 1123: 1106: 1100: 1096: 1092: 1091:The subring 1085: 1081: 1077: 1076:cubic curve 1069: 1061: 1057: 1056:The subring 1050: 1046: 1040: 1030: 1026: 1025:is called a 1022: 1018: 1014: 1010: 1006: 1002: 994: 987: 983: 976: 972: 968: 964: 960: 941: 933: 875:reduced ring 792: 699: 669: 665: 661: 577: 489: 485: 481: 459: 394: 390: 366: 178: 148: 140: 129: 117: 111: 105: 100: 99: 93: 88: 61: 32: 26: 3969:Local rings 3964:Ring theory 3487:: 799–822, 3354:Fulton 1998 3163:line bundle 2881:as well as 2377:finite type 2319:prime ideal 2081:#Properties 886:normal ring 389:-module. A 132:commutative 29:mathematics 3988:Categories 3518:References 3282:2020-03-05 3159:Gorenstein 3099:Hartshorne 2962:See also: 2902:is called 2730:For every 2544:Properties 1235:cohomology 1066:completion 488:is called 397:such that 138:local ring 135:Noetherian 126:Definition 53:local ring 18:Cohen ring 3917:1104.2000 3618:EMS Press 3583:0002-9947 3333:0004-2080 2894:An ideal 2826:⁡ 2754:⁡ 2490:⋯ 2487:⊕ 2474:⊕ 2461:⊕ 2370:connected 2361:-module. 2224:≅ 2161:⊗ 2141:− 2054:⁡ 2033:⋅ 1958:× 1921:× 1825:⋅ 1696:∈ 1634:⊂ 1621:fat point 1572:⋅ 1437:≤ 1338:∈ 1181:≥ 1174:⨁ 1045:The ring 950:reductive 940:zero and 828:… 760:… 537:∈ 281:≤ 162:≠ 3958:See also 3836:(1916), 3795:(2013), 3754:(1998), 3713:(1998), 3672:(1993), 3627:(1995), 3256:archived 3143:a priori 2666:) − dim( 2097:parabola 1265:over an 1074:cuspidal 982:of some 696:Examples 484:-module 151:-module 3934:2932591 3922:Bibcode 3900:0879273 3870:1281612 3827:3057950 3786:1658959 3741:1644323 3704:1234037 3663:1322960 3599:0016094 3591:1990313 3548:1251956 3509:0171804 3501:2373158 3311:Bibcode 3167:regular 3151:sheaves 3121:of two 2904:unmixed 2612:∈ Spec 2414:. Then 2387:). Let 2091:Example 1979:at the 1758:. Then 795:, or a 788:over a 730:, or a 578:maximal 391:maximal 78: ( 66: ( 3932:  3898:  3888:  3868:  3858:  3825:  3815:  3784:  3774:  3739:  3729:  3702:  3692:  3661:  3651:  3597:  3589:  3581:  3546:  3536:  3507:  3499:  3331:  2823:length 2751:length 2702:+1) × 2567:For a 2357:as an 2345:as an 2297:. Let 2051:length 1999:along 1306:scheme 1237:group 1145:be an 999:height 991:matrix 980:minors 879:domain 313:, see 130:For a 3912:arXiv 3587:JSTOR 3497:JSTOR 3259:(PDF) 3252:(PDF) 3181:Notes 3105:: if 3019:with 2877:(See 2652:= dim 2632:Let ( 2595:ideal 2410:over 2402:from 2368:be a 2321:of a 2317:at a 1905:be a 1133:be a 1084:over 1021:+1), 1001:) of 932:when 790:field 668:is a 319:depth 177:is a 35:is a 3886:ISBN 3856:ISBN 3813:ISBN 3772:ISBN 3727:ISBN 3690:ISBN 3649:ISBN 3579:ISSN 3534:ISBN 3329:ISSN 3117:The 2940:The 2678:=1, 2355:free 2343:flat 1995:and 1776:Proj 1478:Spec 1129:Let 1013:+1)( 902:The 891:Any 704:Any 321:and 80:1946 68:1916 31:, a 3848:doi 3805:doi 3764:doi 3682:doi 3641:doi 3569:doi 3489:doi 3319:doi 3173:or 3153:on 3149:of 3101:'s 3069:If 3042:If 2979:If 2970:). 2933:is 2917:of 2802:of 2741:), 2604:If 2597:is 2552:If 2375:of 2353:is 2291:or 1991:of 1983:of 1946:of 1738:of 1149:on 1120:klt 1068:at 660:of 492:if 323:dim 181:if 98:⊃ 27:In 20:or 3990:: 3930:MR 3928:, 3920:, 3896:MR 3894:, 3884:, 3866:MR 3864:, 3854:, 3846:, 3842:, 3823:MR 3821:, 3811:, 3803:, 3799:, 3782:MR 3780:, 3770:, 3762:, 3758:, 3750:; 3737:MR 3735:, 3725:, 3717:, 3700:MR 3698:, 3688:, 3680:, 3676:, 3659:MR 3657:, 3647:, 3639:, 3631:, 3616:, 3610:, 3595:MR 3593:, 3585:, 3577:, 3565:59 3563:, 3544:MR 3542:, 3532:, 3505:MR 3503:, 3495:, 3485:86 3483:, 3327:, 3317:, 3307:29 3305:, 3299:, 3275:, 3254:, 3095:xz 3091:xy 3087:wz 3083:wy 3081:/( 3077:= 3056:xz 3052:xy 3050:/( 3035:/( 3011:= 3003:: 2997:xy 2991:/( 2987:= 2815:, 2717:, 2694:× 2640:, 2636:, 2616:| 2586:/( 2578:, 2540:. 2512:⊂ 2441:, 2426:. 2083:. 2007:: 1897:, 1877:. 1296:. 1288:, 1253:≤ 1245:, 1080:= 1049:/( 986:× 975:× 870:). 457:. 365:a 147:) 116:⊃ 110:⊃ 104:⊃ 3924:: 3914:: 3850:: 3807:: 3766:: 3684:: 3643:: 3571:: 3491:: 3321:: 3313:: 3155:X 3139:X 3111:R 3107:R 3093:, 3089:, 3085:, 3079:K 3075:R 3071:K 3064:z 3062:− 3060:x 3054:, 3048:K 3044:K 3037:x 3033:K 3029:K 3025:y 3021:y 3017:A 3013:K 3009:A 3005:R 2995:, 2993:x 2989:K 2985:R 2981:K 2950:I 2946:A 2931:I 2929:/ 2927:A 2923:I 2921:/ 2919:A 2915:P 2908:I 2900:A 2896:I 2870:. 2858:) 2855:Q 2852:( 2849:e 2846:= 2843:) 2840:Q 2836:/ 2832:R 2829:( 2813:Q 2806:. 2804:Q 2786:) 2783:Q 2780:( 2777:e 2774:= 2771:) 2768:Q 2764:/ 2760:R 2757:( 2735:Q 2725:R 2719:m 2715:R 2710:. 2708:r 2704:r 2700:r 2696:r 2692:r 2680:R 2676:c 2672:c 2668:R 2664:m 2662:/ 2660:m 2658:( 2655:k 2650:c 2646:c 2642:k 2638:m 2634:R 2629:. 2627:R 2622:p 2618:R 2614:R 2610:p 2606:R 2601:. 2588:u 2584:R 2580:R 2576:R 2572:u 2562:R 2558:R 2554:R 2538:A 2534:A 2530:R 2526:R 2522:A 2518:R 2514:R 2510:A 2493:. 2482:2 2478:R 2469:1 2465:R 2458:K 2455:= 2452:R 2439:K 2431:R 2424:f 2420:f 2416:X 2412:K 2408:A 2404:X 2400:f 2393:X 2389:n 2381:K 2366:X 2359:A 2351:R 2347:A 2339:R 2335:R 2331:R 2315:R 2311:R 2307:A 2299:R 2259:) 2254:2 2250:x 2246:( 2241:] 2238:x 2235:[ 2231:C 2218:) 2215:y 2212:( 2207:] 2204:y 2201:, 2198:x 2195:[ 2191:C 2182:] 2179:y 2176:, 2173:x 2170:[ 2166:C 2154:) 2149:2 2145:x 2138:y 2135:( 2130:] 2127:y 2124:, 2121:x 2118:[ 2114:C 2075:. 2063:) 2060:A 2057:( 2048:= 2045:) 2042:X 2039:, 2036:W 2030:V 2027:, 2024:Z 2021:( 2018:i 2005:A 2001:Z 1997:W 1993:V 1985:Z 1967:W 1962:X 1954:V 1944:A 1930:W 1925:X 1917:V 1903:Z 1899:W 1895:V 1891:X 1865:x 1841:) 1833:x 1829:I 1820:C 1816:I 1810:] 1807:z 1804:, 1801:y 1798:, 1795:x 1792:[ 1788:C 1781:( 1772:= 1769:X 1746:C 1724:C 1720:I 1699:C 1693:x 1671:x 1667:I 1644:2 1639:P 1631:C 1607:y 1587:) 1584:y 1581:, 1578:x 1575:( 1569:) 1566:x 1563:( 1539:) 1533:) 1530:y 1527:x 1524:, 1519:2 1515:x 1511:( 1506:] 1503:y 1500:, 1497:x 1494:[ 1490:C 1483:( 1474:= 1471:X 1440:1 1415:g 1409:M 1376:x 1373:, 1370:X 1364:O 1341:X 1335:x 1315:X 1290:O 1286:X 1284:( 1282:H 1278:X 1274:X 1270:X 1263:R 1259:j 1255:n 1251:i 1247:L 1243:X 1241:( 1239:H 1218:) 1213:j 1209:L 1205:, 1202:X 1199:( 1194:0 1190:H 1184:0 1178:j 1170:= 1167:R 1155:L 1151:X 1143:L 1139:n 1131:X 1101:t 1097:K 1093:K 1088:. 1086:K 1082:x 1078:y 1070:t 1062:K 1058:K 1051:x 1047:K 1031:R 1023:R 1019:r 1017:− 1015:q 1011:r 1009:− 1007:p 1003:I 995:S 988:q 984:p 977:r 973:r 969:I 965:S 961:R 956:. 942:G 934:R 918:G 914:R 899:. 888:. 881:. 847:] 844:] 839:n 835:x 831:, 825:, 820:1 816:x 812:[ 809:[ 806:K 793:K 776:] 771:n 767:x 763:, 757:, 752:1 748:x 744:[ 741:K 717:Z 680:R 666:R 662:R 647:m 623:m 618:R 594:m 589:M 560:) 557:M 554:( 550:p 547:p 544:u 541:S 533:m 506:m 501:M 486:M 482:R 468:R 445:) 442:R 439:( 435:m 432:i 429:d 425:= 422:) 419:M 416:( 412:m 409:i 406:d 395:M 377:R 353:R 333:R 301:) 298:M 295:( 291:m 288:i 285:d 278:) 275:M 272:( 268:h 265:t 262:p 259:e 256:d 235:) 232:M 229:( 225:m 222:i 219:d 215:= 212:) 209:M 206:( 202:h 199:t 196:p 193:e 190:d 165:0 159:M 149:R 141:R 24:.

Index

Cohen ring
Cohen algebra
mathematics
commutative ring
algebro-geometric
smooth variety
equidimensionality
local ring
commutative algebra
Francis Sowerby Macaulay
1916
unmixedness theorem
Irvin Cohen
1946
formal power series rings
Universally catenary rings
Cohen–Macaulay rings
Gorenstein rings
complete intersection rings
regular local rings
commutative
Noetherian
local ring
finitely generated
Auslander–Buchsbaum formula
depth
dim
maximal ideals
circular definition
regular local ring

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