Integration problem

Mar 2017
40
0
France
Hi all ! (Smile)

I am trying to go through this paper (https://arxiv.org/pdf/1803.08823.pdf) but am completely stuck on this integration, page 83, which is not explained and given in one step :

Screenshot-2018-4-12 1803 08823 pdf(1).png

Screenshot-2018-4-12 1803 08823 pdf.png

Seems somehow related to the gaussian distribution but I have no idea of the steps.

Thank you very much for your help