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Generic point

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25: 450:, equally, is the fiber above the generic point. Geometry of degeneration is largely then about the passage from generic to special fibers, or in other words how specialization of parameters affects matters. (For a discrete valuation ring the topological space in question is the 458:
have unique generic and special points, but a more complicated spectrum, since they represent general dimensions. The discrete valuation case is much like the complex
543: 500: 264:(that is, it is not the union of two proper algebraic subsets) if and only if the topological space of the subvarieties has a generic point. 524: 108: 375:, always insisted that generic points should be unique. (This can be put back into topologists' terms: Weil's idea fails to give a 348:
but also an infinite supply of fresh indeterminates. This approach worked, without any need to deal directly with the topology of
46: 42: 89: 61: 161: 571: 68: 341: 35: 576: 285: 261: 157: 75: 356:-Zariski topology, that is), because the specializations could all be discussed at the field level (as in the 399: 313:, generic points played an important role, but were handled in a different manner. For an algebraic variety 57: 337: 169: 380: 318: 439: 289: 230: 183: 122: 549: 539: 520: 496: 203: 150: 133: 488: 482: 451: 443: 376: 357: 249: 238: 195: 191: 146: 141: 82: 293: 274: 190:
has a unique generic point, which is the zero ideal. As the closure of this point for the
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In the rapid foundational changes of the 1950s Weil's approach became obsolete. In
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has a (unique) generic point; in the case of an affine integral scheme (i.e., the
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This was at a cost of there being a huge collection of equally generic points.
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over the field generated by the coefficients of the equations of the variety.
459: 519:. Cambridge Tracts in Theoretic Computer Science. Vol. 5. p. 65. 538:. American Mathematical Society Colloquium Publications. Vol. XXIX. 296:) the generic point is the point associated to the prime ideal (0). 168:
is a point such that the field generated by its coordinates has
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are true, a generic property being a property which is true for
18: 410:) consists of two points, a generic point (coming from the 194:
is the whole spectrum, the definition has been extended to
390:, though, from 1957, generic points returned: this time 360:
approach to algebraic geometry, popular in the 1930s).
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In classical algebraic geometry, a generic point of an
49:. Unsourced material may be challenged and removed. 8: 434:), the fiber above the special point is the 248:The terminology arises from the case of the 446:and other theories about degeneration. The 221:A generic point of the topological space 109:Learn how and when to remove this message 470: 438:, an important concept for example in 484:The Red Book of Varieties and Schemes 7: 47:adding citations to reliable sources 379:and Zariski thinks in terms of the 14: 536:Foundations of Algebraic Geometry 311:Foundations of Algebraic Geometry 332:were a whole class of points of 305:In the foundational approach of 277:that has a generic point is the 23: 34:needs additional citations for 1: 16:Concept in algebraic geometry 209:is a point whose closure is 162:projective algebraic variety 493:10.1007/978-3-540-46021-3_2 367:, a colleague of Weil's at 237:, that is, a point that is 593: 481:(2005) . "II Preschemes". 342:algebraically closed field 217:Definition and motivation 515:Vickers, Steven (1989). 487:. Springer. p. 67. 462:, for these purposes.) 422:coming from the unique 400:discrete valuation ring 260:: the algebraic set is 454:of topologists. Other 534:Weil, André (1946). 170:transcendence degree 43:improve this article 426:. For morphisms to 381:Kolmogorov quotient 336:taking values in a 309:, developed in his 572:Algebraic geometry 517:Topology via Logic 440:reduction modulo p 394:. For example for 147:generic properties 123:algebraic geometry 545:978-1-4704-3176-1 502:978-3-540-46021-3 204:topological space 134:algebraic variety 119: 118: 111: 93: 584: 577:General topology 557: 530: 507: 506: 475: 452:Sierpinski space 444:monodromy theory 377:Kolmogorov space 358:valuation theory 338:universal domain 250:Zariski topology 196:general topology 192:Zariski topology 142:general position 139:is a point in a 114: 107: 103: 100: 94: 92: 51: 27: 19: 592: 591: 587: 586: 585: 583: 582: 581: 562: 561: 560: 546: 533: 527: 514: 510: 503: 477: 476: 472: 468: 303: 294:integral domain 286:integral scheme 275:Hausdorff space 270: 219: 188:integral domain 145:, at which all 115: 104: 98: 95: 58:"Generic point" 52: 50: 40: 28: 17: 12: 11: 5: 590: 588: 580: 579: 574: 564: 563: 559: 558: 544: 531: 525: 511: 509: 508: 501: 479:Mumford, David 469: 467: 464: 326:generic points 302: 299: 298: 297: 290:prime spectrum 282: 269: 266: 252:on the set of 218: 215: 117: 116: 31: 29: 22: 15: 13: 10: 9: 6: 4: 3: 2: 589: 578: 575: 573: 570: 569: 567: 555: 551: 547: 541: 537: 532: 528: 526:0-521-36062-5 522: 518: 513: 512: 504: 498: 494: 490: 486: 485: 480: 474: 471: 465: 463: 461: 457: 453: 449: 448:generic fiber 445: 441: 437: 436:special fiber 433: 429: 425: 424:maximal ideal 421: 420:special point 417: 413: 409: 405: 401: 397: 393: 389: 388:scheme theory 384: 382: 378: 374: 370: 366: 365:Oscar Zariski 361: 359: 355: 351: 347: 343: 339: 335: 331: 327: 323: 320: 316: 312: 308: 300: 295: 291: 287: 283: 280: 279:singleton set 276: 272: 271: 267: 265: 263: 259: 258:algebraic set 255: 251: 246: 244: 240: 236: 232: 228: 224: 216: 214: 212: 208: 205: 201: 200:generic point 197: 193: 189: 185: 181: 180:scheme theory 176: 174: 171: 167: 164:of dimension 163: 159: 154: 152: 148: 144: 143: 138: 135: 131: 128: 127:generic point 124: 113: 110: 102: 91: 88: 84: 81: 77: 74: 70: 67: 63: 60: –  59: 55: 54:Find sources: 48: 44: 38: 37: 32:This article 30: 26: 21: 20: 535: 516: 483: 473: 447: 435: 431: 427: 419: 416:closed point 415: 407: 403: 395: 392:à la Zariski 391: 385: 373:World War II 362: 353: 349: 345: 333: 329: 325: 321: 314: 310: 304: 254:subvarieties 247: 242: 234: 226: 222: 220: 210: 206: 199: 177: 172: 165: 155: 151:almost every 140: 136: 129: 126: 120: 105: 96: 86: 79: 72: 65: 53: 41:Please help 36:verification 33: 456:local rings 414:{0}) and a 412:prime ideal 371:just after 344:containing 262:irreducible 225:is a point 566:Categories 554:1030398184 466:References 307:André Weil 233:is all of 198:, where a 69:newspapers 460:unit disk 369:São Paulo 273:The only 99:July 2011 268:Examples 184:spectrum 317:over a 301:History 231:closure 153:point. 83:scholar 552:  542:  523:  499:  340:Ω, an 292:of an 256:of an 229:whose 186:of an 182:, the 158:affine 132:of an 85:  78:  71:  64:  56:  319:field 239:dense 202:of a 90:JSTOR 76:books 550:OCLC 540:ISBN 521:ISBN 497:ISBN 428:Spec 404:Spec 284:Any 125:, a 62:news 489:doi 418:or 383:.) 328:of 241:in 178:In 160:or 121:In 45:by 568:: 548:. 495:. 442:, 402:, 398:a 324:, 245:. 213:. 556:. 529:. 505:. 491:: 432:R 430:( 408:R 406:( 396:R 354:K 352:( 350:V 346:K 334:V 330:V 322:K 315:V 281:. 243:X 235:X 227:P 223:X 211:X 207:X 173:d 166:d 137:X 130:P 112:) 106:( 101:) 97:( 87:· 80:· 73:· 66:· 39:.

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verification
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"Generic point"
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algebraic geometry
algebraic variety
general position
generic properties
almost every
affine
projective algebraic variety
transcendence degree
scheme theory
spectrum
integral domain
Zariski topology
general topology
topological space
closure
dense
Zariski topology
subvarieties
algebraic set

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