$\int_{a}^{b} e^{it\log(\alpha)}e^{-\frac{1}{2}(\frac{\alpha-\mu}{\sigma})^2}d\alpha$?

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I was calculating the characteristic function of a random variable, and I got stuck here at this point

$$\int_{a}^{b} \exp\left(it\log(\alpha)\right)\exp\left(-\frac{1}{2}\left(\frac{\alpha-\mu}{\sigma}\right)^2\right)\mathrm{d}\alpha$$

I really don't know how to proceed from this point, and I would apreciate it if you guys could give me some hints.

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Note that: $$\exp(it\log\alpha)=\alpha^{it}$$

You can then perform a change of variables:$$y=\frac{1}{2}\left(\frac{\alpha-\mu}{\sigma}\right)^2$$

To get an integral of the form: $$\frac{1}{2}\int\left(\sqrt{2y\sigma^2}+\mu\right)^{it-1}e^{-y}dy$$ When $\mu$ is zero, the solution is given directly by a difference between Incomplete Gamma Function. When $\mu\neq0$, we might need some more massaging.