Schild’s Ladder by Greg Egan

Greg Egan is a “hard sci-fi” author. Hard sci-fi is a vague term referring to science fiction with a strong founding in complicated, plausible (if not real) science. He released a few really good novels that deal with several recurring themes including people living entirely as software (and the interactions between such people and those with bodies) some of the issues surrounding duplicating people if they exist as software and some exotic possibilities for life (some not even based on the idea of particle interaction).

That last part is mainly what is expressed in Schild’s Ladder - life existing based on the myriad of possible interactions between different quantum theories that are found to exist in what is originally thought to be a super-stable vacuum. Sounds confusing (and in points it is) but for anyone interested in technical mind bending sci-fi, it’s a must read.

Then go read Diaspora, another book of his following similar themes.