Holy cow, how have people not mentioned Alastair Reynolds? PhD in physics, astronomer, worked for the European space agency, and writer of the incredible revelation space series.

No FTL, but "humanity" has expanded through the Galaxy. Main characters move through deep space in deep sleep on enormous ships called lighthuggers. Long jumps in time. It's a combination of hard sci-fi and space opera. AI and the nature of consciousness are explored. Also very Kim Stanley Robinson in how humans have evolved.

All in all, great, and should be right up your alley.