19 Answers votes newest views recent 12What out-of-print books would you like to see re-printed? 0Primary decomposition of zero-dimensional modules 6Infinite products of topological groups 0How much of differential geometry can be developed entirely without atlases? 12Closed vs Rational Points on Schemes 3Preschemes and schemes 8Quotient of a Hausdorff topological group by a closed subgroup 2A website linking to most major math journals? 6Learning Class Field Theory: Local or Global First? 15Why are flat morphisms “flat?” 2Dolbeault cohomology 1Definition of elementary number theory 5How should one approach tropical mathematics? 2Does automatic decomposition of varieties into irreducibles exist? 2What can’t be described by categories? 2Examples and intuition for arithmetic schemes 3Global fields: What exactly is the analogy between number fields and function fields? 5Sheaf cohomology and injective resolutions 1What is a cup-product in group cohomology, and how does it relate to other branches of mathematics?