@testset "actions on Group[Rings]" begin Eij = PropertyT.EltaryMat ssgs(M::MatAlgebra, i, j) = (S = [Eij(M, i, j), Eij(M, j, i)]; S = unique([S; inv.(S)]); S) rmul = Groups.rmul_autsymbol lmul = Groups.lmul_autsymbol function ssgs(A::AutGroup, i, j) rmuls = [rmul(i,j), rmul(j,i)] lmuls = [lmul(i,j), lmul(j,i)] gen_set = A.([rmuls; lmuls]) return unique([gen_set; inv.(gen_set)]) end @testset "actions on SL(3,Z) and its group ring" begin N = 3 halfradius = 2 M = MatrixAlgebra(zz, N) S = PropertyT.generating_set(M) E_R, sizes = Groups.generate_balls(S, one(M), radius=2halfradius); rdict = GroupRings.reverse_dict(E_R) pm = GroupRings.create_pm(E_R, rdict, sizes[halfradius]; twisted=false); RG = GroupRing(M, E_R, rdict, pm) @testset "correctness of actions" begin Δ = length(S)*RG(1) - sum(RG(s) for s in S) @test Δ == PropertyT.spLaplacian(RG, S) elt = S[5] x = RG(1) - RG(elt) elt2 = E_R[rand(sizes[1]:sizes[2])] y = 2RG(elt2) - RG(elt) for G in [PermGroup(N), WreathProduct(PermGroup(2), PermGroup(N))] @test all(g(one(M)) == one(M) for g in G) @test all(rdict[g(m)] <= sizes[1] for g in G for m in S) @test all(g(m)*g(n) == g(m*n) for g in G for m in S for n in S) @test all(g(Δ) == Δ for g in G) @test all(g(x) == RG(1) - RG(g(elt)) for g in G) @test all(2RG(g(elt2)) - RG(g(elt)) == g(y) for g in G) end end @testset "small Laplacians" begin for (i,j) in PropertyT.indexing(N) Sij = ssgs(M, i,j) Δij= PropertyT.spLaplacian(RG, Sij) @test all(p(Δij) == PropertyT.spLaplacian(RG, ssgs(M, p[i], p[j])) for p in PermGroup(N)) @test all(g(Δij) == PropertyT.spLaplacian(RG, ssgs(M, g.p[i], g.p[j])) for g in WreathProduct(PermGroup(2), PermGroup(N))) end end end @testset "actions on SAut(F_3) and its group ring" begin N = 3 halfradius = 2 M = SAut(FreeGroup(N)) S = PropertyT.generating_set(M) E_R, sizes = Groups.generate_balls(S, one(M), radius=2halfradius); rdict = GroupRings.reverse_dict(E_R) pm = GroupRings.create_pm(E_R, rdict, sizes[halfradius]; twisted=false); RG = GroupRing(M, E_R, rdict, pm) @testset "correctness of actions" begin Δ = length(S)*RG(1) - sum(RG(s) for s in S) @test Δ == PropertyT.spLaplacian(RG, S) elt = S[5] x = RG(1) - RG(elt) elt2 = E_R[rand(sizes[1]:sizes[2])] y = 2RG(elt2) - RG(elt) for G in [PermGroup(N), WreathProduct(PermGroup(2), PermGroup(N))] @test all(g(one(M)) == one(M) for g in G) @test all(rdict[g(m)] <= sizes[1] for g in G for m in S) @test all(g(m)*g(n) == g(m*n) for g in G for m in S for n in S) @test all(g(Δ) == Δ for g in G) @test all(g(x) == RG(1) - RG(g(elt)) for g in G) @test all(2RG(g(elt2)) - RG(g(elt)) == g(y) for g in G) end end for (i,j) in PropertyT.indexing(N) Sij = ssgs(M, i,j) Δij= PropertyT.spLaplacian(RG, Sij) @test all(p(Δij) == PropertyT.spLaplacian(RG, ssgs(M, p[i], p[j])) for p in PermGroup(N)) @test all(g(Δij) == PropertyT.spLaplacian(RG, ssgs(M, g.p[i], g.p[j])) for g in WreathProduct(PermGroup(2), PermGroup(N))) end end end