Haven’t read anything more hard-sci-fi than Egan myself (Clockwork Rocket, quite good). From comments from the OP Egan may not suit (but very recommendable nevertheless)
You're right, it's the wrong book for the OP. Let them be warned:
Greg Egan's Diaspora is diamond-hard scifi. If you aren't well-read in a variety of scientific concepts, aren't comfortable doing on-the-fly physics thought experiments while reading a novel, or won't be comfortable reading an extremely high vocabulary, then Greg Egan is not a good fit.
But if you can read it, the reward is great. Magnificent, alien, profound. It made me realize I don't like soft-scifi.
