...in any case it was Friedman who proposed the first expanding universe model (based on GR). Lemaitre's model was proposed later but nevertheless independently (apparently).
Whilst it's true that Georges Lemaitre was a Catholic Priest that dressed the part, he worked as an astronomer, cosmologist and Physics professor. He was by no means some sort of Vatican sponsored Theologian dabbling in cosmology in order to validate the Book of Genesis.
One would assume that Hubble's Constant was calculated and published by Edwin Hubble himself - it wasn't. Lemaitre was the first to derive Hubbles law and also estimate a value for Hubble's constant. The fact that he wore a Catholic frock and white band around his neck is irrelevant - he was one serious Physicist who contributed in a huge way, during a period where the great Physics Icons where doing their great work.
.........some quantum field effects involve negative energy 