I have two function, $\alpha20$ and $\alpha22$, which are given in terms of some integrals. They depend on some parameters. I fix most of them except $(T,\mu)$. I want to find the roots of these function (equivalently finding $T$) for various parameter $\mu$. I used Findroot but no success specially when I am working with $\alpha22$. These are my functions:
α20[(A_)?NumberQ, (μ_)?NumberQ, (T_)?NumberQ, (ω_)?
NumberQ, (lMin_)?NumberQ, (lMax_)?NumberQ, (Nf_)?NumberQ, (Nc_)?
NumberQ,
(b_)?NumberQ, (Λ_)?NumberQ, (r_)?
NumberQ] := Λ^2/(2*b) -
A^2*((Nf*Nc)/(8*Pi^2))*
NIntegrate[1/τ^2, {τ, Λ^(-2), Infinity},
Method -> {"LocalAdaptive", "SymbolicProcessing" -> 0},
AccuracyGoal -> 10] +
A^2*((Nf*Nc)/(4*Pi^2))*
Sum[NIntegrate[
p*(BesselJ[ℓ, p*r]^2 + BesselJ[ℓ + 1, p*r]^2)*
(1/(E^((Sqrt[
k^2 + p^2] - μ - ω*(ℓ + 1/2))/
T)*((1 +
E^(-((Sqrt[
k^2 + p^2] - μ - ω*(ℓ + 1/2))/
T)))*Sqrt[k^2 + p^2])) +
1/(E^((Sqrt[k^2 + p^2] + μ + ω*(ℓ + 1/2))/
T)*((1 +
E^(-((Sqrt[
k^2 + p^2] + μ + ω*(ℓ + 1/2))/
T)))*Sqrt[k^2 + p^2]))),
{p, 0, Infinity}, {k, 0, Infinity},
Method -> {"LocalAdaptive", "SymbolicProcessing" -> 0},
AccuracyGoal -> 10],
{ℓ, lMin, lMax, 1}]
and
α22[(A_)?NumberQ, (μ_)?NumberQ, (T_)?NumberQ, (ω_)?
NumberQ, (lMin_)?NumberQ, (lMax_)?NumberQ, (Nf_)?NumberQ, (Nc_)?
NumberQ,
(b_)?NumberQ, (Λ_)?NumberQ, (r_)?NumberQ] :=
A^2*((Nf*Nc)/(2*Pi^(5/2)))*
NIntegrate[(1/τ^(1/2))*((3 - 2*k^2*τ)/E^(k^2*τ)),
{k, 0.000001, Infinity}, {τ, Λ^(-2),
Infinity},
Method -> {"LocalAdaptive", "SymbolicProcessing" -> 0},
AccuracyGoal -> 10] -
A^2*((Nf*Nc)/(4*Pi^2))*T*
Sum[NIntegrate[
p*(BesselJ[ℓ, p*r]^2 +
BesselJ[ℓ + 1, p*r]^2)*
((3*E^((3*Sqrt[k^2 + p^2])/T)*p^2*T^2 +
6*E^((3*μ)/T)*p^2*T^2 +
3*E^((3*(Sqrt[k^2 + p^2] +
2*(μ + ω*(ℓ + 1/2))))/T)*p^2*
T^2 +
9*E^((3*Sqrt[k^2 + p^2] +
2*(μ + ω*(ℓ + 1/2)))/T)*p^2*
T*(2*Sqrt[k^2 + p^2] + 3*T) +
9*E^((3*Sqrt[k^2 + p^2] +
4*(μ + ω*(ℓ + 1/2)))/T)*p^2*
T*(2*Sqrt[k^2 + p^2] + 3*T) -
E^((5*Sqrt[k^2 + p^2] +
2*(μ + ω*(ℓ + 1/2)))/T)*(k^4 +
k^2*p^2 - 3*p^2*T*(Sqrt[k^2 + p^2] + T)) -
6*E^((4*Sqrt[k^2 + p^2] +
3*(μ + ω*(ℓ + 1/2)))/T)*(k^4 +
k^2*p^2 - 3*p^2*T*(Sqrt[k^2 + p^2] + T)) -
E^((5*Sqrt[k^2 + p^2] +
4*(μ + ω*(ℓ + 1/2)))/T)*(k^4 +
k^2*p^2 - 3*p^2*T*(Sqrt[k^2 + p^2] + T)) +
E^((4*Sqrt[
k^2 + p^2] + (μ + ω*(ℓ +
1/2)))/T)*(k^4 + k^2*p^2 +
3*p^2*T*(Sqrt[k^2 + p^2] + 2*T)) +
6*E^((2*Sqrt[k^2 + p^2] +
3*(μ + ω*(ℓ + 1/2)))/T)*(k^4 +
k^2*p^2 + 3*p^2*T*(Sqrt[k^2 + p^2] + 2*T)) +
E^((4*Sqrt[k^2 + p^2] +
5*(μ + ω*(ℓ + 1/2)))/T)*(k^4 +
k^2*p^2 + 3*p^2*T*(Sqrt[k^2 + p^2] + 2*T)) -
E^((2*Sqrt[
k^2 + p^2] + (μ + ω*(ℓ +
1/2)))/T)*(k^4 + k^2*p^2 -
3*p^2*T*(Sqrt[k^2 + p^2] + 4*T)) -
E^((2*Sqrt[k^2 + p^2] +
5*(μ + ω*(ℓ + 1/2)))/T)*(k^4 +
k^2*p^2 - 3*p^2*T*(Sqrt[k^2 + p^2] + 4*T)) +
E^((Sqrt[k^2 + p^2] +
2*(μ + ω*(ℓ + 1/2)))/T)*(k^4 +
k^2*p^2 + 3*p^2*T*(Sqrt[k^2 + p^2] + 5*T)) +
E^((Sqrt[k^2 + p^2] +
4*(μ + ω*(ℓ + 1/2)))/T)*(k^4 +
k^2*p^2 + 3*p^2*T*(Sqrt[k^2 + p^2] + 5*T)))/
((E^(Sqrt[k^2 + p^2]/T) +
E^((μ + ω*(ℓ + 1/2))/T))^3*(1 +
E^((Sqrt[
k^2 + p^2] + μ + ω*(ℓ + 1/2))/
T))^3*(k^2 + p^2)^(5/2)*
T^2)), {p, 0.000001, Infinity}, {k, 0.000001, Infinity},
Method -> {"LocalAdaptive", "SymbolicProcessing" -> 0},
AccuracyGoal -> 10],
{ℓ, lMin, lMax, 1}];
I use Findroot to find $T$ for different values of $\mu$. But the code run for a long period of time and I do not receive any results (specially for $\alpha22$).This is my sample code
Block[{A = N[1], lMin = -2, lMax = 2, Nf = 2,
Nc = 3, Λ = 0.86, r = 0.1,
b = 11, ω = 0.05},
list = {};
Table[roots =
FindRoot[α22[A, μ, T, ω, lMin, lMax, Nf, Nc,
b, Λ, r], {T, 0.05}, Method -> "Newton"];
roots2 =
FindRoot[α20[A, μ, T, ω, lMin, lMax, Nf, Nc,
b, Λ, r], {T, 0.05}, Method -> "Newton"];
AppendTo[
list, {roots[[1, 2]],roots2[[1, 2]], μ, ω}]; , {μ,
0.36, 0.4, 0.005}]]
Is there a way to find roots of these function? I also want the code run a bit faster! Any help is appreciated.
FindRoot
to work on one sample case before launching on the full parameter search with Table? $\endgroup$