Changeset 7abf40 in git
- Timestamp:
- Feb 18, 2011, 10:09:44 AM (13 years ago)
- Branches:
- (u'spielwiese', '8e0ad00ce244dfd0756200662572aef8402f13d5')
- Children:
- 607fc78e355f385cd271cf9b760410b83c6a6a75
- Parents:
- 673ee3c38462387be8b4ece27179dfbf664273ba
- Location:
- Singular/LIB
- Files:
-
- 2 edited
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Singular/LIB/gmspoly.lib
r673ee3 r7abf40 1 1 /////////////////////////////////////////////////////////////////////////////// 2 version="$Id $";2 version="$Id: gmspoly.lib 12529 2010-02-08 15:57:48Z seelisch $"; 3 3 category="Singularities"; 4 4 … … 6 6 LIBRARY: gmspoly.lib Gauss-Manin System of Tame Polynomials 7 7 8 AUTHOR: Mathias Schulze, email: mschulze@mathematik.uni-kl.de 9 10 OVERVIEW: A library to compute invariants related to the Gauss-Manin system 11 of a cohomologically tame polynomial 8 AUTHOR: Mathias Schulze, mschulze at mathematik.uni-kl.de 9 10 OVERVIEW: 11 A library for computing the Gauss-Manin system of a cohomologically tame 12 polynomial f. Schulze's algorithm [Sch05], based on Sabbah's theory [Sab98], 13 is used to compute a good basis of (the Brieskorn lattice of) the Gauss-Manin system and the differential operation of f in terms of this basis. 14 In addition, there is a test for tameness in the sense of Broughton. 15 Tame polynomials can be considered as an affine algebraic analogue of local 16 analytic isolated hypersurface singularities. They have only finitely many 17 citical points, and those at infinity do not give rise to atypical values 18 in a sense depending on the precise notion of tameness considered. Well-known 19 notions of tameness like tameness, M-tameness, Malgrange-tameness, and 20 cohomological tameness, and their relations, are reviewed in [Sab98,§8]. 21 For ordinary tameness, see Broughton [Bro88,§3]. 22 Sabbah [Sab98] showed that the Gauss-Manin system, the D-module direct image 23 of the structure sheaf, of a cohomologically tame polynomial carries a 24 similar structure as in the isolated singularity case, coming from a Mixed 25 Hodge structure on the cohomology of the Milnor (typical) fibre (see 26 gmssing.lib). The data computed by this library encodes the differential structure of the Gauss-Manin system, and the Mixed Hodge structure of the Milnor fibre over the complex numbers. As a consequence, it yields the Hodge numbers, spectral pairs, and monodromy at infinity. 27 28 REFERENCES: 29 [Bro88] S. Broughton: Milnor numbers and the topology of polynomial 30 hypersurfaces. Inv. Math. 92 (1988) 217-241. 31 [Sab98] C. Sabbah: Hypergeometric periods for a tame polynomial. 32 arXiv.org math.AG/9805077. 33 [Sch05] M. Schulze: Good bases for tame polynomials. 34 J. Symb. Comp. 39,1 (2005), 103-126. 12 35 13 36 PROCEDURES: 14 isTame(f); test ifthe polynomial f is tame15 goodBasis(f); a good basis of the Brieskorn lattice of a cohomologically tamef37 isTame(f); test whether the polynomial f is tame 38 goodBasis(f); good basis of Brieskorn lattice of cohom. tame polynomial f 16 39 17 40 SEE ALSO: gmssing_lib … … 60 83 @format 61 84 int k= 85 1; if f is tame in the sense of Broughton [Bro88,§3] 62 86 0; if f is not tame 63 1; if f is tame64 87 @end format 88 REMARKS: procedure implements Proposition 3.1 in [Bro88] 65 89 KEYWORDS: tame polynomial 66 90 EXAMPLE: example isTame; shows examples … … 138 162 /////////////////////////////////////////////////////////////////////////////// 139 163 140 static proc vfilt Tuple(matrix B,int d)164 static proc vfiltmat(matrix B,int d) 141 165 { 142 166 int mu=ncols(B); … … 426 450 proc goodBasis(poly f) 427 451 "USAGE: goodBasis(f); poly f 428 ASSUME: f is cohomologically tame 452 ASSUME: f is cohomologically tame in the sense of Sabbah [Sab98,§8] 429 453 RETURN: 430 454 @format … … 433 457 matrix A; A(s)=A0+s*A1 and t[matrix(b)]=[matrix(b)](A(s)+s^2*(d/ds)) 434 458 @end format 459 REMARKS: procedure implements Algorithm 6 in [Sch05] 435 460 KEYWORDS: tame polynomial; Gauss-Manin system; Brieskorn lattice; 436 461 mixed Hodge structure; V-filtration; weight filtration; 437 462 monodromy; spectrum; spectral pairs; good basis 463 SEE ALSO: gmssing_lib 438 464 EXAMPLE: example goodBasis; shows examples 439 465 " … … 517 543 B=pidbasis(K2,L2); 518 544 } 545 519 546 B0=std(coeffs(reduce(matrix(K,nrows(K),nrows(B))*B,JS),b0)); 520 547 b=matrix(K,nrows(K),nrows(B))*B; … … 527 554 setring(@S); 528 555 529 e0,s0,V,B=vfilt Tuple(imap(@XS,A),d);556 e0,s0,V,B=vfiltmat(imap(@XS,A),d); 530 557 a,e0,e,s,V,B,G=spec(e0,s0,V,B); 531 558 -
Singular/LIB/gmssing.lib
r673ee3 r7abf40 1 1 /////////////////////////////////////////////////////////////////////////////// 2 version="$Id $";2 version="$Id: gmssing.lib 13548 2010-10-19 07:45:40Z hannes $"; 3 3 category="Singularities"; 4 4 … … 6 6 LIBRARY: gmssing.lib Gauss-Manin System of Isolated Singularities 7 7 8 AUTHOR: Mathias Schulze, email: mschulze@mathematik.uni-kl.de 9 10 OVERVIEW: A library to compute invariants related to the the Gauss-Manin system 11 of an isolated hypersurface singularity 8 AUTHOR: Mathias Schulze, mschulze at mathematik.uni-kl.de 9 10 OVERVIEW: 11 A library for computing invariants related to the Gauss-Manin system of an 12 isolated hypersurface singularity. 13 14 REFERENCES: 15 [Sch01] M. Schulze: Algorithms for the Gauss-Manin connection. J. Symb. Comp. 16 32,5 (2001), 549-564. 17 [Sch02] M. Schulze: The differential structure of the Brieskorn lattice. 18 In: A.M. Cohen et al.: Mathematical Software - ICMS 2002. 19 World Scientific (2002). 20 [Sch03] M. Schulze: Monodromy of Hypersurface Singularities. 21 Acta Appl. Math. 75 (2003), 3-13. 22 [Sch04] M. Schulze: A normal form algorithm for the Brieskorn lattice. 23 J. Symb. Comp. 38,4 (2004), 1207-1225. 12 24 13 25 PROCEDURES: … … 38 50 KEYWORDS: singularities; Gauss-Manin system; Brieskorn lattice; 39 51 mixed Hodge structure; V-filtration; weight filtration; 40 Bernstein-Sato polynomial; local Bernstein-Sato polynomial;41 monodromy; spectrum; spectral pairs;good basis52 Bernstein-Sato polynomial; monodromy; spectrum; spectral pairs; 53 good basis 42 54 "; 43 55 … … 590 602 @end format 591 603 KEYWORDS: singularities; Gauss-Manin system; Brieskorn lattice; 592 Bernstein-Sato polynomial ; local Bernstein-Sato polynomial604 Bernstein-Sato polynomial 593 605 EXAMPLE: example bernstein; shows examples 594 606 " … … 1240 1252 proc sppnf(list sp) 1241 1253 "USAGE: sppnf(list(a,w[,m])); ideal a, intvec w, intvec m 1242 ASSUME: ncols( e)==size(w)==size(m)1254 ASSUME: ncols(a)==size(w)==size(m) 1243 1255 RETURN: order (a[i][,w[i]]) with multiplicity m[i] lexicographically 1244 1256 EXAMPLE: example sppnf; shows examples
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