In algebra, a normal homomorphism is a ring homomorphism R → S {\displaystyle R\to S} that is flat and is such that for every field extension L of the residue field κ ( p ) {\displaystyle \kappa ({\mathfrak {p}})} of any prime ideal p {\displaystyle {\mathfrak {p}}} , L ⊗ R S {\displaystyle L\otimes _{R}S} is a normal ring.
References Huneke, Craig; Swanson, Irena (2006), "Ch. 19", Integral closure of ideals, rings, and modules, London Mathematical Society Lecture Note Series, vol. 336, Cambridge, UK: Cambridge University Press, ISBN 978-0-521-68860-4, MR 2266432, archived from the original on 2019-11-15, retrieved 2015-04-24