Stalinism is defined by policies of state terror, state centralization, purging the government and maintaining a cult of personality. Those are pretty extreme positions to hold.
Historically, many of Stalin's actions were not seen keenly in France, including Stalin's Gulags, his pact with Hitler, and over the cold war, his territorial aggressivity over the USSR's satellite countries. You may note that France was very decidedly on the other side of the Iron Curtain.
There definitely were quite a few socialists, there were a few communists, there probably were few Leninists, but I doubt there were any Stalinists. I'd be interested in the scientist's name if you found one.
The communist party was the largest political party in France after the war and it was fully and openly aligned to Moscow. You may (and should) interpret being a stalinist as a bad thing today but it wasn't at that time for a large portion of the left.
But my point is rather that being good at math and at creating mathematical representations of nature doesn't qualify someone to make decisions on how other people should live their life.
