[dchanin@ace-math01 ~]$ magma Magma V2.21-4 Tue Sep 1 2015 20:48:22 on ace-math01 [Seed = 1173772051] Type ? for help. Type -D to quit > load "autcv9.txt"; Loading "autcv9.txt" > Mmats,Gmats,Q,C:=RunExample(SmallGroup(24,12),4,[2,2,2,4]); Character Table of Group G -------------------------- ----------------------- Class | 1 2 3 4 5 Size | 1 3 6 8 6 Order | 1 2 2 3 4 ----------------------- p = 2 1 1 1 4 2 p = 3 1 2 3 1 5 ----------------------- X.1 + 1 1 1 1 1 X.2 + 1 1 -1 1 -1 X.3 + 2 2 0 -1 0 X.4 + 3 -1 -1 0 1 X.5 + 3 -1 1 0 -1 Conjugacy Classes of group G ---------------------------- [1] Order 1 Length 1 Rep Id(G) [2] Order 2 Length 3 Rep G.3 [3] Order 2 Length 6 Rep G.1 [4] Order 3 Length 8 Rep G.2 [5] Order 4 Length 6 Rep G.1 * G.3 SKGs: [ G.1, G.1 * G.2 * G.4, G.1 * G.3 * G.4, G.1 * G.2^2 * G.3 * G.4 ] Is hyperelliptic? false Is cyclic trigonal? false Multiplicities of irreducibles in relevant G-modules: I_1 =[ 0, 0, 0, 0, 0 ] S_1 =[ 0, 1, 0, 1, 0 ] H^0(C,1K)=[ 0, 1, 0, 1, 0 ] I_2 =[ 1, 0, 0, 0, 0 ] S_2 =[ 2, 0, 1, 0, 2 ] H^0(C,2K)=[ 1, 0, 1, 0, 2 ] I_3 =[ 0, 2, 0, 1, 0 ] S_3 =[ 0, 3, 1, 4, 1 ] H^0(C,3K)=[ 0, 1, 1, 3, 1 ] I2timesS1=[ 0, 1, 0, 1, 0 ] Is clearly not generated by quadrics? true Matrix generators for action on H^0(C,K): Field K Cyclotomic Field of order 24 and degree 8 [ [-1 0 0 0] [ 0 -1 -1 0] [ 0 0 1 0] [ 0 0 1 -1], [ 1 0 0 0] [ 0 1 0 1] [ 0 0 0 -1] [ 0 0 1 -1], [ 1 0 0 0] [ 0 0 -1 1] [ 0 -1 0 -1] [ 0 0 0 -1], [ 1 0 0 0] [ 0 -1 0 0] [ 0 1 0 1] [ 0 1 1 0] ] Surface Kernel Generators: [ [-1 0 0 0] [ 0 -1 -1 0] [ 0 0 1 0] [ 0 0 1 -1], [-1 0 0 0] [ 0 1 0 0] [ 0 -1 -1 0] [ 0 -1 0 -1], [-1 0 0 0] [ 0 0 0 1] [ 0 0 -1 0] [ 0 1 0 0], [-1 0 0 0] [ 0 1 0 1] [ 0 -1 0 0] [ 0 -1 -1 0] ] Finding quadrics: I2 contains a 1-dimensional subspace of CharacterRow 1 Dimension 2 Multiplicity 2 [ a^2, b^2 - b*c - b*d + c^2 + c*d + d^2 ] Finding cubics: I3 contains a 2-dimensional subspace of CharacterRow 2 Dimension 3 Multiplicity 3 [ a^3, a*b^2 - a*b*c - a*b*d + a*c^2 + a*c*d + a*d^2, b^2*c + b^2*d - b*c^2 - 2*b*c*d - b*d^2 + c^2*d + c*d^2 ] I3 contains a 3-dimensional subspace of CharacterRow 4 Dimension 12 Multiplicity 4 [ a^2*b, a^2*c, a^2*d, a*b^2 - a*d^2, a*b*c + a*b*d - a*c*d - a*d^2, a*c^2 - a*d^2, b^3 + d^3, b^2*c - b*c^2 + 2/3*d^3, b^2*d - b*d^2 + 2/3*d^3, b*c*d + 1/3*d^3, c^3 - d^3, c^2*d + c*d^2 + 2/3*d^3 ] > K:=CyclotomicField(24); > P3:=ProjectiveSpace(K,3); > mu3:=z^3; > X:=Scheme(P3,[a^2+b^2 - b*c - b*d + c^2 + c*d + d^2,(a^3-(a*b^2 - a*b*c - a*\ b*d + a*c^2 + a*c*d + a*d^2)) + mu2*(b^2*c + b^2*d - b*c^2 -2*b*c*d - b*d^2 + \ c^2*d + c*d^2)]); > Dimension(X); 1 > IsSingular(X); false > Automorphism(X,Mmats[1]); Mapping from: Sch: X to Sch: X with equations : -a -b -b + c + d -d and inverse -a -b -b + c + d -d > Automorphism(X,Mmats[2]); Mapping from: Sch: X to Sch: X with equations : a b d b - c - d and inverse a b b - c - d c > Automorphism(X,Mmats[3]); Mapping from: Sch: X to Sch: X with equations : a -c -b b - c - d and inverse a -c -b b - c - d > Automorphism(X,Mmats[4]); Mapping from: Sch: X to Sch: X with equations : a -b + c + d d c and inverse a -b + c + d d c