Commit 45b5fadd authored by Gonzalo Tornaría's avatar Gonzalo Tornaría

a different version of ModPhis

parent 9867426c
......@@ -254,6 +254,46 @@ intrinsic ModPhis1(m :: Modularity, R2 :: FldNum) -> Map, []
end intrinsic;
intrinsic ModPhis2(m :: Modularity, R2 :: FldNum) -> Map, []
{ return proj:gal2->gal1 and a list of all possible phi:gal2->VG }
proj := galois_projection(m`R1, R2);
gal2 := Domain(proj);
ans := [* *];
for VG in m`VGs do
b, phi := IsIsomorphic(gal2, VG`self);
if b then
//print "dim:", Dimension(VG), #m`auts[VG], #VG, #Center(VG`self);
// pi : VG --> G;
pi := VG`pi;
// rho : gal1 -> G;
rho := m`rho;
for psi in m`auts[VG] do
phi1 := phi * psi;
for x in VG`self do
// check phi1 * inner_x * pi eq proj * rho
if &and [ pi(x^-1*phi1(g)*x) eq rho(proj(g))
: g in Generators(gal2) ]
then
Append(~ans, phi1);
break psi;
end if;
end for;
end for;
end if;
end for;
return proj, ans;
end intrinsic;
/////////////////////////
// sorted degrees for a factorization (from high to low)
degrees := func<fact | Reverse(Sort([AbsoluteDegree(f[1]): f in fact]))>;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment