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MatFac15 :: constructEx6

constructEx6 -- randomly choose a module N with Betti table as indicated in o4 below

Synopsis

Description

We follow the random construction of an element of the family from Thm 4.9 and 4.10 as explained in Matrix factorizations and families of curves of genus 15

i1 : kk=ZZ/10007;S=kk[x_0..x_4];
i3 : N=constructEx6(S);
i4 : betti res N

            0  1  2 3
o4 = total: 7 15 12 4
         0: 7 15  4 .
         1: .  .  8 3
         2: .  .  . 1

o4 : BettiTally
i5 : (M0,M1)=matrixFactorizationFromModule(N);
i6 : tangentKernelDimension(N,M0)==7

o6 = true
i7 : N=constructEx6(S,{(4,1)});
i8 : betti res N

            0  1  2 3
o8 = total: 7 15 12 4
         3: 7 15  4 .
         4: .  .  8 3
         5: .  .  . 1

o8 : BettiTally
i9 : (M0,M1)=matrixFactorizationFromModule(N);
i10 : tangentKernelDimension(N,M0)==9

o10 = true
i11 : N=constructEx6(S,14);
i12 : betti res N

             0  1  2 3
o12 = total: 7 15 12 4
          0: 7 15  4 .
          1: .  .  8 3
          2: .  .  . 1

o12 : BettiTally
i13 : E=annihilator N; (degree E,genus E)==(14,14)

o13 : Ideal of S

o14 = true
i15 : (M0,M1)=matrixFactorizationFromModule(N);
i16 : tangentKernelDimension(N,M0)==3

o16 = true
i17 : betti res E

             0 1 2 3
o17 = total: 1 6 9 4
          0: 1 . . .
          1: . . . .
          2: . 6 3 .
          3: . . 6 4

o17 : BettiTally

Ways to use constructEx6 :

  • constructEx6(PolynomialRing)
  • constructEx6(PolynomialRing,List)
  • constructEx6(PolynomialRing,ZZ)