Changeset 4f461c in git
- Timestamp:
- Mar 5, 2010, 2:28:28 PM (13 years ago)
- Branches:
- (u'spielwiese', '0d6b7fcd9813a1ca1ed4220cfa2b104b97a0a003')
- Children:
- 24c3680c7cb6e7c29e4766bc33d10684a0c2e1f2
- Parents:
- 8a7e767173900998af700bab01a16d332d191b3d
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Singular/LIB/dmodvar.lib
r8a7e76 r4f461c 4 4 info=" 5 5 LIBRARY: dmodvar.lib Algebraic D-modules for varieties 6 6 7 AUTHORS: Daniel Andres, daniel.andres@math.rwth-aachen.de 7 @*Viktor Levandovskyy, levandov@math.rwth-aachen.de8 @*Jorge Martin-Morales, jorge@unizar.es8 Viktor Levandovskyy, levandov@math.rwth-aachen.de 9 Jorge Martin-Morales, jorge@unizar.es 9 10 10 11 THEORY: Let K be a field of characteristic 0. Given a polynomial ring 11 @*R = K[x_1,...,x_n] and a set of polynomial f_1,..., f_r in R, define12 @*F = f_1 * ... * f_r and F^s:=f_1^s_1*...*f_r^s_r for symbolic discrete13 @*(that is shiftable) variables s_1,..., s_r.14 @* The module R[1/F]*F^s has a structure of a D<S>-module, where 15 @*D<S> := D(R) tensored with S over K, where16 @*- D(R) is an n-th Weyl algebra K<x_1,...,x_n,d_1,...,d_n | d_j x_j = x_j d_j +1>17 @*- S is the universal enveloping algebra of gl_r, generated by s_{ij}, where s_{ii}=s_i.18 @*One is interested in the following data:19 @*- the left ideal Ann F^s in D<S>, usually denoted by LD in the output20 @*- global Bernstein polynomial in one variable s = s_1 + ...+ s_r, denoted by bs,21 @*- its minimal integer root s0, the list of all roots of bs, which are known22 @*to be rational, with their multiplicities, which is denoted by BS23 @*- an r-tuple of operators in D<S>, denoted by PS, such that the functional equality24 @*sum(k=1 to k=r) P_k*f_k*F^s = bs*F^s holds in R[1/F]*F^s.12 R = K[x_1,...,x_n] and a set of polynomial f_1,..., f_r in R, define 13 F = f_1 * ... * f_r and F^s:=f_1^s_1*...*f_r^s_r for symbolic discrete 14 (that is shiftable) variables s_1,..., s_r. 15 The module R[1/F]*F^s has a structure of a D<S>-module, where 16 D<S> := D(R) tensored with S over K, where 17 - D(R) is an n-th Weyl algebra K<x_1,...,x_n,d_1,...,d_n | d_j x_j = x_j d_j +1> 18 - S is the universal enveloping algebra of gl_r, generated by s_{ij}, where s_{ii}=s_i. 19 One is interested in the following data: 20 - the left ideal Ann F^s in D<S>, usually denoted by LD in the output 21 - global Bernstein polynomial in one variable s = s_1 + ...+ s_r, denoted by bs, 22 - its minimal integer root s0, the list of all roots of bs, which are known 23 to be rational, with their multiplicities, which is denoted by BS 24 - an r-tuple of operators in D<S>, denoted by PS, such that the functional equality 25 sum(k=1 to k=r) P_k*f_k*F^s = bs*F^s holds in R[1/F]*F^s. 25 26 26 27 REFERENCES: 27 @*(BMS06) Budur, Mustata, Saito: Bernstein-Sato polynomials of arbitrary varieties (2006).28 @*(ALM09) Andres, Levandovskyy, Martin-Morales : Principal Intersection and Bernstein-Sato Polynomial of an Affine Variety (2009).28 (BMS06) Budur, Mustata, Saito: Bernstein-Sato polynomials of arbitrary varieties (2006). 29 (ALM09) Andres, Levandovskyy, Martin-Morales : Principal Intersection and Bernstein-Sato Polynomial of an Affine Variety (2009). 29 30 30 31 MAIN PROCEDURES: … … 166 167 // the case: given ORD, given engine 167 168 eng = int(#[2]); 168 } 169 } 169 170 else 170 171 { … … 197 198 int ppl = printlevel-voice+2; 198 199 // returns a list with a ring and an ideal LD in it 199 // save, N, P and the indices are already defined 200 // save, N, P and the indices are already defined 200 201 int Nnew = 2*N+P+P^2; 201 202 list RL = ringlist(basering); … … 328 329 intvec iv = P+1..Nnew; 329 330 tmpM = imap(@R@,@D); 330 kill @R@; 331 kill @R@; 331 332 LordM = submat(tmpM,iv,iv); 332 333 matrix @D2 = LordM; … … 548 549 // Name, Dname will be used further 549 550 kill NName, TName, Name, DTName, DName; 550 // ORD already set, default ord dp; 551 // ORD already set, default ord dp; 551 552 L[3] = ORDstr2list(ORD,Nnew); 552 553 // we are done with the list … … 605 606 @* Varnames of the basering do not include t(1),...,t(r) and 606 607 @* Dt(1),...,Dt(r), where r is the number of entries of the input ideal. 607 BACKGROUND: In this proc, the initial ideal of the multivariate Malgrange ideal 608 BACKGROUND: In this proc, the initial ideal of the multivariate Malgrange ideal 608 609 @* defined by I is computed and then a system of linear equations is solved 609 610 @* by linear reductions following the ideas by Noro. … … 619 620 @* time. 620 621 @* If b<>0, @code{std} is used for GB computations in characteristic 0, 621 @* otherwise, and by default, @code{slimgb} is used. 622 @* otherwise, and by default, @code{slimgb} is used. 622 623 @* If c<>0, a matrix ordering is used for GB computations, otherwise, 623 624 @* and by default, a block ordering is used. … … 838 839 I = std(I); 839 840 //ideal I = z(6)^2-z(3)*z(7), z(5)*z(6)-z(2)*z(7), z(5)^2-z(1)*z(7), 840 // z(4)*z(5)-z(3)*z(6), z(3)*z(5)-z(2)*z(6), z(2)*z(5)-z(1)*z(6), 841 // z(4)*z(5)-z(3)*z(6), z(3)*z(5)-z(2)*z(6), z(2)*z(5)-z(1)*z(6), 841 842 // z(3)^2-z(2)*z(4), z(2)*z(3)-z(1)*z(4), z(2)^2-z(1)*z(3); 842 843 bfctVarIn(I,1); // no result yet
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