/* 2"A10 as 16 x 16 matrices over Z. Absolutely irreducible representation. Schur index 1. SEED: Nonzero v fixed by = L2(8). (Stabiliser of v is L2(8):3, and of is 2 x L2(8):3.) v has 2 x 1200 = 2400 images under G; has 1200 images under G. BASIS: All in v^G. Possible matrix entries are in {-2,-1,0,1,2}. Average number of nonzero entries for any element of the group: 109 + 11/25 (109.44; 42.75% exactly). Entry Av/Mat %Av/Mat 0 146.56 [146 + 14/25] 57.25 [57 + 1/4] nonzero 109.44 [109 + 11/25] 42.75 [42 + 3/4] ±1 107.52 [107 + 13/25] 42 [42 ] ±2 1.92 [ 1 + 23/25] 0.75 [ + 3/4] 1 53.76 [ 53 + 19/25] 21 [21 ] -1 53.76 [ 53 + 19/25] 21 [21 ] 2 0.96 [ 24/25] 0.375 [ + 3/8] -2 0.96 [ 24/25] 0.375 [ + 3/8] p-MODULAR REDUCTIONS: p = 5: 8a.8b (uniserial, both factors absolutely irreducible). Module labelling should be the same as elsewhere in the web-ATLAS. other: absolutely irreducible. LATTICE DETAILS: Aut grp: 2"A10. Minimum: 6. Kiss no: 2400. Determinant: 390625. Elmnty divs: 1^8.5^8. Theta series: 1 + 2400*q^6 + 10800*q^8 + 60480*q^10 + 223200*q^12 + 626400*q^14 + 1609200*q^16 + 3681600*q^18 + 7801920*q^20 + 14904000*q^22 + 27729600*q^24 + 48168000*q^26 + 81410400*q^28 + 132030240*q^30 + O(q^31). Minimum vectors are all in v^G. */ F:=RationalField(); Z:=Integers(); G:=MatrixGroup<16,F|\[ 0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0, -1,-1,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,-1,-1,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,-1,-1,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,-1,-1,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,-1,-1,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,-1,-1,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,-1,-1,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1,-1] ,\[ 0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0, -1,0,-1,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,-1,0,0,0,0, 0,0,0,0,0,0,0,0,0,1,-1,0,0,0,0,0, 0,0,0,0,0,0,0,-1,0,0,0,0,0,-1,0,-1, 0,0,0,0,0,0,0,1,0,0,0,0,0,1,-1,0, 0,0,0,0,0,0,0,0,0,-1,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,-1,0,0,-1,0,0,0,0, 0,1,0,1,0,0,0,-1,0,0,0,0,0,0,0,0, 1,0,1,0,0,0,0,1,0,0,0,0,0,0,0,0, 0,0,-1,-1,0,-1,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,-1,0,0,0,0,0,0,0,0,0,0,0, 1,0,1,0,0,0,0,1,-1,-1,0,0,0,1,0,0, 0,0,0,0,0,0,0,0,0,0,1,0,1,0,1,1] >; A:=x;B:=y; // Forms: B1 (Symmetric). // B1 (Symmetric form): Determinant 390625 [e.divs: 1^8.5^8]. B1:=MatrixAlgebra(F,16)!\[ 6,-3,-3,2,3,-1,1,0,1,2,1,0,-3,3,0,0, -3,6,1,-3,-2,3,-1,1,-3,1,-1,1,0,-3,0,0, -3,1,6,-3,-3,0,2,-3,1,-1,0,-3,1,0,-3,2, 2,-3,-3,6,3,-3,1,2,0,1,3,0,-1,1,1,-3, 3,-2,-3,3,6,-3,-1,3,0,3,2,0,-1,0,0,0, -1,3,0,-3,-3,6,-2,-1,-3,0,-2,2,1,-1,0,0, 1,-1,2,1,-1,-2,6,-3,2,0,3,-3,-3,3,-2,-1, 0,1,-3,2,3,-1,-3,6,-2,2,0,3,0,-3,3,-2, 1,-3,1,0,0,-3,2,-2,6,-3,0,-3,0,3,0,0, 2,1,-1,1,3,0,0,2,-3,6,3,0,-3,0,0,0, 1,-1,0,3,2,-2,3,0,0,3,6,-3,-3,2,-1,-2, 0,1,-3,0,0,2,-3,3,-3,0,-3,6,1,-3,3,-1, -3,0,1,-1,-1,1,-3,0,0,-3,-3,1,6,-3,-1,1, 3,-3,0,1,0,-1,3,-3,3,0,2,-3,-3,6,0,-1, 0,0,-3,1,0,0,-2,3,0,0,-1,3,-1,0,6,-3, 0,0,2,-3,0,0,-1,-2,0,0,-2,-1,1,-1,-3,6]; // Centralising algebra: Scalars only. C1:=MatrixAlgebra(F,16)!1; L1:=MatrixAlgebra(Z,16)!B1; LA1:=LatticeWithGram(L1); // AU1:=AutomorphismGroup(LA1); // AU1 = G = 2"A10.