Virtual Cartier divisors and blow-ups
arXiv:1802.05702 · doi:10.1007/s00029-025-01060-7
Abstract
We prove a universal property for blow-ups in regularly immersed subschemes, based on a notion we call "virtual effective Cartier divisor". We also construct blow-ups of quasi-smooth closed immersions in derived algebraic geometry.
19 pages; version 2 adds a comparison between virtual and generalized Cartier divisors, a new section on simultaneous blow-ups in multiple centres and blow-ups in unramified centres, and a new co-author