I would like to approximate the following integral for large $t$ :
$I(t)=\int_0^{\pi}dx f(x)e^{iS(x)t}$
$S$ is real and $S'(0)=S'(\pi)=0$.
$f$ is real and $f(0)=f(\pi)=0$ and $f'(0)=f'(\pi)=0$.
Can one do this for this type of integral?
Thank you.
I would like to approximate the following integral for large $t$ :
$I(t)=\int_0^{\pi}dx f(x)e^{iS(x)t}$
$S$ is real and $S'(0)=S'(\pi)=0$.
$f$ is real and $f(0)=f(\pi)=0$ and $f'(0)=f'(\pi)=0$.
Can one do this for this type of integral?
Thank you.