Schild's Ladder

"Schild's Ladder" by Greg Egan

Greg Egan is a great visionary, his ideas and ingenuities are profound and intelligent. His works exude a kind of brilliance, a technological devotion to the big ideas, but at a cost: sometimes the ideas take the stage, and characters and plot are bystanders. Overall, they are still excellent, and they're big on the ideas. A warning: it's the hardest hard sci-fi out there, for example, the book Schild's Ladder is full of hardcore mathematics and physics.