Dragon’s Egg is my favorite hard SF novel. I remember attending a session with Robert Forward at an early 1980s World Science Fiction Convention and was amazed at how much detail science and math Forward put into his books.
https://scp-wiki.wikidot.com/antimemetics-division-hub
(The extended universe of this story is the Fifthist Church, which is usually written as a kind of hippie Scientology and has a pretty different feel.)