I have the function $$F(z)=\int_{\Bbb R}f(z,t)\ dt$$ $z\mapsto f(z,t)$ is analytic. How can I prove $F$ is analytic?
We assume that the integral exists.
I wanted to show it is derivable by using the theorem of derivation under the $\int$ sign but I don't think I can apply it to functions of a complex variable as I can to functions of real variables.
(In general I guess $F$ will not be analytic, but I want to have some techniques to prove if it is analytic. Which theorem can help me here for example)