K-theory (generalized cohomology theories). (~400 articles)
Analysis/simulation of conservative PDEs. (100+ articles)
Banach spaces/functional analysis. (~400 articles, arXiv overlay)
A repository of eprints about optimisation and related topics.
Papers by Saharon Shelah in logic and related. (100s of articles, arXiv mirrored)
Including Azumaya Algebras, Algebras with Involutions, Brauer Groups, Quadratic and Hermitean Forms...