1
0
mirror of https://github.com/kalmarek/SmallHyperbolic synced 2024-11-12 20:55:29 +01:00
SmallHyperbolic/adj_psl2_eigvals.jl

247 lines
7.0 KiB
Julia
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

using RamanujanGraphs
using LinearAlgebra
using Arblib
using ArgParse
using Logging
using Dates
import RamanujanGraphs.Primes: isprime
include(joinpath(@__DIR__, "src", "eigen_utils.jl"))
function SL2p_gens(p::Integer)
@assert isprime(p)
if p == 31
a, b = let
a = SL₂{p}([8 14; 4 11])
b = SL₂{p}([23 0; 14 27])
@assert isone(a^10)
@assert isone(b^10)
a, b
end
elseif p == 41
a, b = let
a = SL₂{p}([0 28; 19 35])
b = SL₂{p}([38 27; 2 9])
@assert isone(a^10)
@assert isone(b^10)
a, b
end
elseif p == 109
a, b = let
a = SL₂{p}([0 1; 108 11])
b = SL₂{p}([57 2; 52 42])
@assert isone(a^10)
@assert isone(b^10)
a, b
end
elseif p == 131
a, b = let
a = SL₂{p}([-58 -24; -58 46])
b = SL₂{p}([0 -3; 44 -12])
@assert isone(a^10)
@assert isone(b^10)
a, b
end
else
@warn "no special set of generators for prime $p"
a, b = let
a = SL₂{p}(1, 0, 1, 1)
b = SL₂{p}(1, 1, 0, 1)
a, b
end
end
return a,b
end
function adjacency(ϱ, a, b; prec=256)
order_a = findfirst(i-> isone(a^i), 1:100)
order_b = findfirst(i-> isone(b^i), 1:100)
@assert !isnothing(order_a) && order_a > 1
@assert !isnothing(order_b) && order_b > 1
k = order_a-1 + order_b-1
A = AcbMatrix(ϱ(a), prec=prec)
B = AcbMatrix(ϱ(b), prec=prec)
res = sum(A^i for i = 1:order_a-1) + sum(B^i for i = 1:order_b-1)
return Arblib.scalar_div!(res, res, k)
end
function parse_our_args()
s = ArgParseSettings()
@add_arg_table! s begin
"-p"
help = "the prime p for which to use PSL(2,p)"
arg_type = Int
required = true
"-a"
help = "generator a (optional)"
"-b"
help = "generator b (optional)"
"--ab"
help = "array of generators a and b (optional)"
"--precision"
help = "set the precision of computations"
arg_type = Int
default = 128
end
result = parse_args(s)
for key in ["a", "b", "ab"]
val = get(result, key, "")
if val != nothing
result[key] = eval(Meta.parse(val))
else
delete!(result, key)
end
end
val = get(result, "ab", "")
if val != ""
result["a"] = val[1]
result["b"] = val[2]
end
result
end
parsed_args = parse_our_args()
const p = let p = parsed_args["p"]
isprime(p) || @error "You need to provide a prime, ex: `julia adj_psl2_eigvals.jl -p 31`"
p
end
const PRECISION = parsed_args["precision"]
const LOGFILE = joinpath("log", "SL(2,$p)_eigvals_$(now()).log")
open(LOGFILE, "w") do io
@info "Logging into $LOGFILE"
with_logger(SimpleLogger(io)) do
@info "Arguments:" args=parsed_args
a,b = SL2p_gens(p)
a = SL₂{p}(get(parsed_args, "a", a))
b = SL₂{p}(get(parsed_args, "b", b))
@info "Generators" a b
Borel_cosets = let p = p, (a,b) = (a,b)
SL2p, sizes =
RamanujanGraphs.generate_balls([a, b, inv(a), inv(b)], radius = 21)
@assert sizes[end] == RamanujanGraphs.order(SL₂{p})
RamanujanGraphs.CosetDecomposition(SL2p, Borel(SL₂{p}))
end
all_large_evs = Arb[]
let α = RamanujanGraphs.generator(RamanujanGraphs.GF{p}(0))
for j = 0:(p-1)÷4
h = PrincipalRepr(
α => unit_root((p - 1) ÷ 2, j, prec=PRECISION),
Borel_cosets,
)
@time adj = adjacency(h, a, b, prec=PRECISION)
try
@time evs = let evs = safe_eigvals(adj)
count_multiplicites(evs)
end
append!(all_large_evs, [real(first(x)) for x in evs[1:2]])
@info "Principal Series Representation $j" evs[1:2] evs[end]
catch ex
@error "Principal Series Representation $j failed" ex
ex isa InterruptException && rethrow(ex)
end
end
end
let α = RamanujanGraphs.generator(RamanujanGraphs.GF{p}(0)),
β = RamanujanGraphs.generator_min(QuadraticExt(α))
if p % 4 == 1
ub = (p - 1) ÷ 4
ζ = unit_root((p + 1) ÷ 2, 1, prec=PRECISION)
else # p % 4 == 3
ub = (p + 1) ÷ 4
ζ = unit_root((p + 1), 1, prec=PRECISION)
end
for k = 1:ub
h = DiscreteRepr(
RamanujanGraphs.GF{p}(1) => unit_root(p, prec=PRECISION),
β => ζ^k,
)
@time adj = adjacency(h, a, b, prec=PRECISION)
try
@time evs = let evs = safe_eigvals(adj)
count_multiplicites(evs)
end
append!(all_large_evs, [real(first(x)) for x in evs[1:2]])
@info "Discrete Series Representation $k" evs[1:2] evs[end]
catch ex
@error "Discrete Series Representation $k : failed" ex
ex isa InterruptException && rethrow(ex)
end
end
end
all_large_evs = sort(all_large_evs, rev=true)
λ = all_large_evs[2]
ε = (λ - 3)/5
α = acos(ε)
α_deg = (α/pi)*180
@info "Certified values:" λ ε α α_deg
end # with_logger
end # open(logfile)
#
# using RamanujanGraphs.LightGraphs
# using Arpack
#
# Γ, eigenvalues = let p = 109,
# a = PSL₂{p}([ 0 1; 108 11]),
# b = PSL₂{p}([ 57 2; 52 42])
#
# S = unique([[a^i for i in 1:4]; [b^i for i in 1:4]])
#
# @info "Generating set S of $(eltype(S))" S
# @time Γ, verts, vlabels, elabels =
# RamanujanGraphs.cayley_graph(RamanujanGraphs.order(PSL₂{p}), S)
#
# @assert all(LightGraphs.degree(Γ,i) == length(S) for i in vertices(Γ))
# @assert LightGraphs.nv(Γ) == RamanujanGraphs.order(PSL₂{p})
# A = adjacency_matrix(Γ)
# @time eigenvalues, _ = eigs(A, nev=5)
# @show Γ eigenvalues
# Γ, eigenvalues
# end
#
# let p = 131,
# a = PSL₂{p}([-58 -24; -58 46]),
# b = PSL₂{p}([0 -3; 44 -12])
#
# S = unique([[a^i for i in 1:4]; [b^i for i in 1:4]])
#
# @info "Generating set S of $(eltype(S))" S
# @time Γ, verts, vlabels, elabels =
# RamanujanGraphs.cayley_graph(RamanujanGraphs.order(PSL₂{p}), S)
#
# @assert all(LightGraphs.degree(Γ,i) == length(S) for i in vertices(Γ))
# @assert LightGraphs.nv(Γ) == RamanujanGraphs.order(PSL₂{p})
# A = adjacency_matrix(Γ)
# @time eigenvalues, _ = eigs(A, nev=5)
# @show Γ eigenvalues
# Γ, eigenvalues
# end