-- -*- M2-comint -*- {* hash: 646509695 *} i1 : Quintic = Proj(QQ[x_0..x_4]/ideal(x_0^5+x_1^5+x_2^5+x_3^5+x_4^5-101*x_0*x_1*x_2*x_3*x_4)) o1 = Quintic o1 : ProjectiveVariety i2 : singularLocus(Quintic) /QQ[x , x , x , x , x ]\ | 0 1 2 3 4 | o2 = Proj|----------------------| \ 1 / o2 : ProjectiveVariety i3 : omegaQuintic = cotangentSheaf(Quintic); i4 : h11 = rank HH^1(omegaQuintic) o4 = 1 i5 : h12 = rank HH^2(omegaQuintic) o5 = 101 i6 : h21 = rank HH^1(cotangentSheaf(2,Quintic)) o6 = 101 i7 : hh^(2,1)(Quintic) o7 = 101 i8 : hh^(1,1)(Quintic) o8 = 1 i9 : euler(Quintic) o9 = -200 i10 : SchoensQuintic = Proj(QQ[x_0..x_4]/ideal(x_0^5+x_1^5+x_2^5+x_3^5+x_4^5-5*x_0*x_1*x_2*x_3*x_4)) o10 = SchoensQuintic o10 : ProjectiveVariety i11 : Z = singularLocus(SchoensQuintic) o11 = Z o11 : ProjectiveVariety i12 : degree Z o12 = 125 i13 : II'Z = sheaf module ideal Z o13 = image | x_3^4-x_0x_1x_2x_4 x_0x_1x_2x_3-x_4^4 x_2^4-x_0x_1x_3x_4 x_1^4-x_0x_2x_3x_4 x_0^4-x_1x_2x_3x_4 x_2^3x_3^3-x_0^2x_1^2x_4^2 x_1^3x_3^3-x_0^2x_2^2x_4^2 x_0^3x_3^3-x_1^2x_2^2x_4^2 x_1^2x_2^2x_3^2-x_0^3x_4^3 x_0^2x_2^2x_3^2-x_1^3x_4^3 x_0^2x_1^2x_3^2-x_2^3x_4^3 x_1^3x_2^3-x_0^2x_3^2x_4^2 x_0^3x_2^3-x_1^2x_3^2x_4^2 x_0^2x_1^2x_2^2-x_3^3x_4^3 x_0^3x_1^3-x_2^2x_3^2x_4^2 | 1 o13 : coherent sheaf on Proj(QQ[x , x , x , x , x ]), subsheaf of OO 0 1 2 3 4 Proj(QQ[x , x , x , x , x ]) 0 1 2 3 4 i14 : defect = rank HH^1(II'Z(5)) o14 = 24 i15 : h11 = defect + 1 o15 = 25 i16 : quinticsJac = numgens source basis(5,ideal Z) o16 = 25 i17 : h21 = rank HH^0(II'Z(5)) - quinticsJac o17 = 0 i18 : chiW = euler(Quintic)+2*degree(Z) o18 = 50 i19 :