// (150,5) signature (2,3,10) K:=CyclotomicField(5); P2:=ProjectiveSpace(K,2); X:=Scheme(P2,[y_0^5+y_1^5+y_2^5]); IsSingular(X); A:=Matrix([ [0,-z_5^2,0], [-z_5^3,0,0], [0,0,-1] ]); B:=Matrix([ [0,0,z_5^2], [1,0,0], [0,z_5^3,0] ]); Order(A); Order(B); Order( (A*B)^(-1)); GL3K:=GeneralLinearGroup(3,K); IdentifyGroup(sub); Automorphism(X,A); Automorphism(X,B); // (120,34) signature (2,4,6) /* Inoue Kato equations u_0:=-x_3-x_1-x_2; u_1:=-x_4-x_2-x_0; u_2:=-x_5-x_0-x_1; u_3:=-x_0-x_4-x_5; u_4:=-x_1-x_5-x_3; u_5:=-x_2-x_3-x_4; X:=Scheme(P5,[x_0*u_0-x_1*u_1, x_0*u_0-x_2*u_2, x_0*u_0+x_3*u_3, x_0*u_0+x_4*u_4, x_0*u_0+x_5*u_5, x_0^2+u_0^2+x_1^2+u_1^2+x_2^2+u_2^2+x_3^2+u_3^2+x_4^2+u_4^2+x_5^2+u_5^2]); */ K:=RationalField(); P5:=ProjectiveSpace(K,5); X:=Scheme(P5,[ 4*x_0^2 + 2*x_0*x_1 + 4*x_1^2 + 2*x_0*x_2 + 2*x_1*x_2 + 4*x_2^2 + 4*x_1*x_3 + 4*x_2*x_3 + 4*x_3^2 + 4*x_0*x_4 + 4*x_2*x_4 + 2*x_3*x_4 + 4*x_4^2 + 4*x_0*x_5 + 4*x_1*x_5 + 2*x_3*x_5 + 2*x_4*x_5 + 4*x_5^2, -x_0*x_2 + x_1*x_2 - x_0*x_3 + x_1*x_4, -x_0*x_1 + x_1*x_2 - x_0*x_3 + x_2*x_5, -x_0*x_1 - x_0*x_2 - 2*x_0*x_3 - x_3*x_4 - x_3*x_5, -x_0*x_1 - x_0*x_2 - x_0*x_3 - x_1*x_4 - x_3*x_4 - x_4*x_5, -x_0*x_1 - x_0*x_2 - x_0*x_3 - x_2*x_5 - x_3*x_5 - x_4*x_5 ]); Dimension(X); IsSingular(X); HilbertPolynomial(Ideal(X)); A:=Matrix([ [0,0,0,0,-1,0], [0,-1,1,0,-1,1], [-1,0,0,0,0,1], [-1,0,1,-1,0,1], [-1,0,0,0,0,0], [0,0,1,0,-1,0] ]); B:=Matrix([ [0,0,1,0,-1,0], [-1,0,1,-1,0,1], [-1,0,0,0,0,0], [-1,0,0,0,0,1], [0,0,0,0,-1,0], [0,-1,1,0,-1,1] ]); Order(A); Order(B); Order( (A*B)^(-1)); GL6K:=GeneralLinearGroup(6,K); IdentifyGroup(sub); Automorphism(X,A); Automorphism(X,B); // (72,15) signature (2,4,9) K:=CyclotomicField(36); z_12:=z_36^3; z_9:=z_36^4; z_6:=z_36^6; z_3:=z_36^12; P5:=ProjectiveSpace(K,5); X:=Scheme(P5,[ x_0*x_2-x_1^2, x_0*x_4-x_1*x_3, x_0*x_5-x_2*x_3, x_1*x_4-x_0*x_5, x_1*x_5-x_2*x_4, x_3*x_5-x_4^2, x_0^3+(4*z_6-2)*x_0^2*x_2+x_0*x_2^2+x_3^3+(-4*z_6+2)*x_3^2*x_5+x_3*x_5^2, x_0^2*x_1+(4*z_6-2)*x_0*x_1*x_2+x_1*x_2^2+x_3^2*x_4+(-4*z_6+2)*x_3*x_4*x_5+x_4*x_5^2, x_0^2*x_2+(4*z_6-2)*x_0*x_2^2+x_2^3+x_3^2*x_5+(-4*z_6+2)*x_3*x_5^2+x_5^3 ]); Dimension(X); IsSingular(X); HilbertPolynomial(Ideal(X)); A:=Matrix([ [0, 0, 0, -z_9/2, z_36^13/2, z_9/2], [0, 0, 0, -z_36^13, 0, -z_36^13], [0, 0, 0, z_9/2, z_36^13/2, -z_9/2], [z_36^14/2, z_36^5/2, -z_36^14/2, 0, 0, 0], [-z_36^5, 0, -z_36^5, 0, 0, 0], [-z_36^14/2, z_36^5/2, z_36^14/2, 0, 0, 0] ]); B:=Matrix([ [0, 0, 0, z_12^5, 0, 0], [0, 0, 0, 0, z_3^2, 0], [0, 0, 0, 0, 0, -z_12^5], [z_12, 0, 0, 0, 0, 0], [0, z_3, 0, 0, 0, 0], [0, 0, -z_12, 0, 0, 0] ]); Order(A); Order(B); Order( (A*B)^(-1)); GL6K:=GeneralLinearGroup(6,K); IdentifyGroup(sub); Automorphism(X,A); Automorphism(X,B); // (48,15) signature (2,6,8) K:=CyclotomicField(24); z_8:=z_24^3; i:=z_24^6; z_6:=z_24^4; z_3:=z_24^8; P5:=ProjectiveSpace(K,5); X:=Scheme(P5,[ -x_4^2 + x_3*x_5, -x_2*x_4 + x_1*x_5, -x_2*x_3 + x_1*x_4, -x_2*x_3 + x_0*x_5, -x_1*x_3 + x_0*x_4, -x_1^2 + x_0*x_2, x_0*x_1^2 - x_2^3 - x_3*x_4^2 - x_5^3, x_0^2*x_1 - x_1*x_2^2 - x_3^2*x_4 - x_4*x_5^2, x_0^3 - x_1^2*x_2 - x_3^3 - x_4^2*x_5 ]); Dimension(X); IsSingular(X); HilbertPolynomial(Ideal(X)); A:=Matrix([ [0,0,0,0,0,-z_8], [0,0,0,0,i,0], [0,0,0,-z_8^3,0,0], [0,0,z_8,0,0,0], [0,-i,0,0,0,0], [z_8^3,0,0,0,0,0] ]); B:=Matrix([ [0,0,-z_6,0,0,0], [0,z_6,0,0,0,0], [-z_6,0,0,0,0,0], [0,0,0,0,0,-z_3], [0,0,0,0,z_3,0], [0,0,0,-z_3,0,0] ]); Order(A); Order(B); Order( (A*B)^(-1)); GL6K:=GeneralLinearGroup(6,K); IdentifyGroup(sub); Automorphism(X,A); Automorphism(X,B); // (39,1) signature (2,3,13) K:=CyclotomicField(13); P2:=ProjectiveSpace(K,2); X:=Scheme(P2,[y_0^4*y_1+y_1^4*y_2+y_2^4*y_0]); IsSingular(X); A:=Matrix([ [0,0,z_13^12], [z_13^4,0,0], [0,z_13^10,0] ]); B:=Matrix([ [0,z_13^7,0], [0,0,z_13^11], [z_13^8,0,0] ]); Order(A); Order(B); Order( (A*B)^(-1)); GL3K:=GeneralLinearGroup(3,K); IdentifyGroup(sub); Automorphism(X,A); Automorphism(X,B); // (30,1) signature (2,10,15) K:=CyclotomicField(5); P2:=ProjectiveSpace(K,2); X:=Scheme(P2,[y_0^5+y_1^4*y_2+2*z_5*y_1^3*y_2^2+2*z_5^2*y_1^2*y_2^3+z_5^3*y_1*y_2^4]); IsSingular(X); A:=Matrix([ [1,0,0], [0,0,z_5^4], [0,z_5,0] ]); B:=Matrix([ [z_5^3,0,0], [0,-z_5,0], [0,-z_5^2,z_5] ]); Order(A); Order(B); Order( (A*B)^(-1)); GL3K:=GeneralLinearGroup(3,K); IdentifyGroup(sub); Automorphism(X,A); Automorphism(X,B); // (21,2) K:=CyclotomicField(21); z_7:=z_21^3; z_3:=z_21^7; P5:=ProjectiveSpace(K,5); X:=Scheme(P5,[ x_0*x_3-x_1*x_2, x_0*x_4-x_1*x_3, x_0*x_5-x_1*x_4, x_2*x_4-x_3^2, x_2*x_5-x_3*x_4, x_3*x_5-x_4^2, x_0^3-x_3*x_5^2 +x_2^3, x_0^2*x_1-x_4*x_5^2 + x_2^2*x_3, x_0*x_1^2-x_5^3+x_2^2*x_4 ]); Dimension(X); IsSingular(X); HilbertPolynomial(Ideal(X)); A:=DiagonalMatrix([z_3^2,z_3^2,z_3,z_3,z_3,z_3]); B:=DiagonalMatrix([1,z_7,1,z_7,z_7^2,z_7^3]); GL6K:=GeneralLinearGroup(6,K); Order(A); Order(B); Order( (A*B)^(-1)); IdentifyGroup(sub); Automorphism(X,A); Automorphism(X,B); // (60,5) signature (2,2,2,3) K:=CyclotomicField(60); p:=-z_60^14+z_60^6+z_60^4; P5:=ProjectiveSpace(K,5); c_1:=1; X:=Scheme(P5,[ x_0^2+x_0*x_1+p*x_0*x_2+x_1^2+(p-1)*x_1*x_2+x_2^2+c_1*(x_3^2-p*x_3*x_4-p*x_3*x_5+x_4^2+x_4*x_5+x_5^2), 24*x_0^2+24*x_0*x_3+(12*p+12)*x_0*x_5+(36*p+12)*x_1*x_4+(36*p+12)*x_1*x_5+(-8*p-16)*x_2^2+(-36*p-12)*x_2*x_4+(48*p+36)*x_2*x_5+(-288*p-180)*x_3^2+(396*p+252)*x_3*x_4+(540*p+324)*x_3*x_5+(-126*p-72)*x_4^2+(-252*p-144)*x_4*x_5+(-234*p-144)*x_5^2, 24*x_0*x_1+(-24*p-36)*x_0*x_3+(36*p+18)*x_0*x_4+(30*p+6)*x_0*x_5+(-54*p-36)*x_1*x_3+(24*p+18)*x_1*x_4+(42*p+18)*x_1*x_5+8*x_2^2+(-18*p-18)*x_2*x_3+(48*p+18)*x_2*x_4+(6*p+6)*x_2*x_5+(117*p+72)*x_3^2+(-108*p-72)*x_3*x_4+(-108*p-54)*x_3*x_5+(-18*p-9)*x_4^2+(-36*p-18)*x_4*x_5+(27*p+18)*x_5^2, 24*x_0*x_2+(6*p-6)*x_0*x_3+(-18*p-18)*x_0*x_4+12*p*x_0*x_5+(-6*p-12)*x_1*x_4+(-6*p-12)*x_1*x_5+(8*p+8)*x_2^2+18*p*x_2*x_3+(-12*p-6)*x_2*x_4+(-18*p-6)*x_2*x_5+(90*p+54)*x_3^2+(-18*p-18)*x_3*x_4+(-270*p-162)*x_3*x_5+(-45*p-27)*x_4^2+(72*p+54)*x_4*x_5+(153*p+99)*x_5^2, (-24*p+12)*x_0*x_3+(36*p+12)*x_0*x_5+24*x_1^2+(36*p+36)*x_1*x_3+(-12*p-12)*x_1*x_4+(-12*p-12)*x_1*x_5+(8*p-24)*x_2^2+(-24*p+12)*x_2*x_4+(12*p+24)*x_2*x_5+(-216*p-126)*x_3^2+(360*p+216)*x_3*x_4+(216*p+108)*x_3*x_5+(-108*p-72)*x_4^2+(-216*p-144)*x_4*x_5+18*p*x_5^2, (6*p+12)*x_0*x_3+(-24*p-18)*x_0*x_5+24*x_1*x_2+(18*p+18)*x_1*x_3+(-6*p+6)*x_1*x_4+(-24*p-12)*x_1*x_5+(8*p-16)*x_2^2+(-12*p-6)*x_2*x_4+(-18*p-6)*x_2*x_5+(-45*p-27)*x_3^2+(-18*p-18)*x_3*x_4+(108*p+54)*x_3*x_5+(90*p+54)*x_4^2+18*p*x_4*x_5+(-90*p-63)*x_5^2] ); Dimension(X); IsSingular(X); HilbertPolynomial(Ideal(X)); A:=Matrix([ [-p, 0, 1, 0, 0, 0], [0, -1, 0, 0, 0, 0], [-p, 0, p, 0, 0, 0], [0, 0, 0, -1, 0, 0], [0, 0, 0, 0, 0, -1], [0, 0, 0, 0, -1, 0] ]); B:=Matrix([ [0, -1, 0, 0, 0, 0], [-1, 0, 0, 0, 0, 0], [1, -1, -1, 0, 0, 0], [0, 0, 0, 0, 1, 0], [0, 0, 0, 1, 0, 0], [0, 0, 0, -p, -p, -1] ]); C:=Matrix([ [-p, p-1, p-1, 0, 0, 0], [-p, p-1, p, 0, 0, 0], [-1, 1, 0, 0, 0, 0], [0, 0, 0, -1, 0, -p], [0, 0, 0, 0, -1, 1], [0, 0, 0, 0, 0, 1] ]); Order(A); Order(B); Order(C); Order( (A*B*C)^(-1)); GL6K:=GeneralLinearGroup(6,K); IdentifyGroup(sub); Automorphism(X,A); Automorphism(X,B); Automorphism(X,C); // (24,12) signature (2,2,3,4) K:=QuadraticField(3); P5:=ProjectiveSpace(K,5); c_7:=2/t; c_5:=t/2; c_2:=13; X:=Scheme(P5,[ x_0^2 - x_0*x_1 + x_0*x_2 + x_1^2 + x_2^2+c_2*(x_3^2 - x_3*x_5 + x_4^2 - x_4*x_5 + x_5^2), x_0*x_3 + x_0*x_4 - 1/2*x_0*x_5 - 1/2*x_1*x_3 - 3/2*x_1*x_4 + x_1*x_5 + 3/2*x_2*x_3 + 1/2*x_2*x_4 - x_2*x_5+c_5*(x_3^2 - 2*x_3*x_4 + x_4^2 - x_5^2), 1/4*x_0*x_3 + 1/4*x_0*x_4 - 1/2*x_0*x_5 + 1/4*x_1*x_3 - 3/4*x_1*x_4 + 1/4*x_1*x_5 + 3/4*x_2*x_3 - 1/4*x_2*x_4 - 1/4*x_2*x_5+c_5*(1/2*x_3^2 + x_3*x_4 - x_3*x_5 + 1/2*x_4^2 - x_4*x_5), x_0^2 + 2*x_0*x_2+ c_7*(x_0*x_3 - x_1*x_5) -2*x_4*x_5 + x_5^2, x_0*x_1 + x_0*x_2 + c_7*(1/2*x_0*x_3 - 1/2*x_0*x_4 - 1/2*x_1*x_5 - 1/2*x_2*x_5) + x_3*x_5 - x_4*x_5, x_1^2 - x_2^2 + c_7*(x_0*x_3 - x_0*x_4 + x_1*x_4 - x_1*x_5 + x_2*x_3 - x_2*x_5) + x_3^2 - x_4^2 ]); Dimension(X); IsSingular(X); HilbertPolynomial(Ideal(X)); A:=Matrix([ [-1, -1, 1, 0, 0, 0], [0, 0, -1, 0, 0, 0], [0, -1, 0, 0, 0, 0], [0, 0, 0, 0, 1, 0], [0, 0, 0, 1, 0, 0], [0, 0, 0, -1, -1, -1] ]); B:=Matrix([ [-1, 0, 1, 0, 0, 0], [0, -1, 0, 0, 0, 0], [0, 0, 1, 0, 0, 0], [0, 0, 0, 1, 0, 0], [0, 0, 0, 0, -1, 0], [0, 0, 0, 0, 1, 1] ]); C:=Matrix([ [1, 1, 0, 0, 0, 0], [-1, -1, 1, 0, 0, 0], [1, 0, 0, 0, 0, 0], [0, 0, 0, -1, -1, -1], [0, 0, 0, 0, 0, -1], [0, 0, 0, 1, 0, 1] ]); Order(A); Order(B); Order(C); Order( (A*B*C)^(-1)); GL6K:=GeneralLinearGroup(6,K); IdentifyGroup(sub); Automorphism(X,A); Automorphism(X,B); Automorphism(X,C); // (24,8) signature (2,2,3,4) K:=CyclotomicField(12); z_6:=z_12^2; z_3:=z_12^4; t:=17+z_12^5; P5:=ProjectiveSpace(K,5); X:=Scheme(P5,[ x_0*x_2-x_1^2, x_0*x_4-x_1*x_3, x_0*x_5-x_2*x_3, x_1*x_4-x_0*x_5, x_1*x_5-x_2*x_4, x_3*x_5-x_4^2, x_0^3+t*x_0^2*x_2+x_0*x_2^2+x_3^3-t*x_3^2*x_5+x_3*x_5^2, x_0^2*x_1+t*x_0*x_1*x_2+x_1*x_2^2+x_3^2*x_4-t*x_3*x_4*x_5+x_4*x_5^2, x_0^2*x_2+t*x_0*x_2^2+x_2^3+x_3^2*x_5-t*x_3*x_5^2+x_5^3 ]); Dimension(X); IsSingular(X); HilbertPolynomial(Ideal(X)); A:=Matrix([ [0, 0, 0, 0, 0, z_12^5], [0, 0, 0, 0, z_6, 0], [0, 0, 0, z_12^-1, 0, 0], [0, 0, z_12, 0, 0, 0], [0, -z_6+1, 0, 0, 0, 0], [-z_12, 0, 0, 0, 0, 0] ]); B:=Matrix([ [0, 0, 1, 0, 0, 0], [0, -1, 0, 0, 0, 0], [1, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 1], [0, 0, 0, 0, -1, 0], [0, 0, 0, 1, 0, 0] ]); C:=Matrix([ [z_3, 0, 0, 0, 0, 0], [0, z_3, 0, 0, 0, 0], [0, 0, z_3, 0, 0, 0], [0, 0, 0, z_3^2, 0, 0], [0, 0, 0, 0, z_3^2, 0], [0, 0, 0, 0, 0, z_3^2] ]); Order(A); Order(B); Order(C); Order( (A*B*C)^(-1)); GL6K:=GeneralLinearGroup(6,K); IdentifyGroup(sub); Automorphism(X,A); Automorphism(X,B); Automorphism(X,C); // (24,6) signature (2,2,3,4) locus 17 K:=CyclotomicField(24); z_12:=z_24^2; z_6:=z_24^4; z_3:=z_6^2; i:=z_24^6; P5:=ProjectiveSpace(K,5); t:=17+z_24^5; X:=Scheme(P5,[ x_0*x_2-x_1^2, x_0*x_4-x_1*x_3, x_1*x_4-x_2*x_3, x_0*x_5-x_1*x_4, x_1*x_5-x_2*x_4, x_3*x_5-x_4^2, x_0*x_2^2+t*x_0^3+t*x_5^2*x_3+x_3^3, x_1*x_2^2+t*x_0^2*x_1+t*x_5^2*x_4+x_3^2*x_4, x_2^3+t*x_0^2*x_2+t*x_5^3+x_3^2*x_5 ]); Dimension(X); IsSingular(X); HilbertPolynomial(Ideal(X)); A:=Matrix([ [0,0,0,0,0,-z_12^-1], [0,0,0,0,z_6,0], [0,0,0,z_12^-1,0,0], [0,0,z_12,0,0,0], [0,-z_3,0,0,0,0], [-z_12,0,0,0,0,0] ]); B:=Matrix([ [0,0,0,0,0,-z_3], [0,0,0,0,z_3,0], [0,0,0,-z_3,0,0], [0,0,z_6,0,0,0], [0,-z_6,0,0,0,0], [z_6,0,0,0,0,0] ]); C:=DiagonalMatrix([z_3^2,z_3^2,z_3^2,z_3,z_3,z_3]); Order(A); Order(B); Order(C); Order( (A*B*C)^-1); GL6K:=GeneralLinearGroup(6,K); IdentifyGroup(sub); Automorphism(X,A); Automorphism(X,B); Automorphism(X,C);