The integral equation: $$ \int_{-\frac{T}{2}}^{\frac{T}{2}}dt' \phi (t')e^{\Gamma\left | t-t' \right |} =\lambda \phi(t) $$
for $(-\frac{1}{2}T< t < \frac{1}{2}T)$
is useful in photon counting statistics theory.
Show that the eigenvalues $\lambda_k$ of the above equation are given by $$ \Gamma \lambda_k = \frac{2}{1+u^{2}_k} $$
where the $u_k$ are the roots of the transcendental equation
$$ tan(\Gamma T u_k) = \frac{2 u_k}{u^{2}_k - 1} $$
Using this solve for the eigenfunctions associated
The $\Gamma$ here is a constant. I can see that the kernel is an exponential. I've worked this numerous times using Fredholms technique but repeatidly hit a brick wall. Am I missing something?