Let $(R,m)$ be an excellent local ring. Suppose $R$ is a normal ring.
I would like to show that
the formal fibers $k(p)\otimes \hat{R}$ ($\hat{R}$ is the $m$-adic completion of $R$) are also normal for all $p\in Spec(R).$
Excellent rings are new to me. I could not show the above. It would be really helpful if someone explain the proof of the above.