21 Answers votes newest views recent 5Prime Number Theorem w/o Complex Analysis 6Omega_1 Categorical Theory 3More open problems 4Where does the game-theoretic characterization of PH come from? 6How can I force the continuum to be weakly compact? 12Math puzzles for dinner 8Applications of the Chinese remainder theorem 4When can we prove constructively that a ring with unity has a maximal ideal? 5Fundamental Examples 1Is there a non self-referencing non-computable function? 3Is the existence of a well-ordering on R independent of ZF? 6Independence from Set Theory Axioms 10Is there a formula phi s.t. phi and not-phi have a stronger consistency? 22Is no proof based on “tertium non datur” sufficient any more after Gödel? 46What are some reasonable-sounding statements that are independent of ZFC? (2) 39Do good math jokes exist? 5What do models where the CH is false look like? 3Is the “diagonal” of a regular language always context-free? 16Does finite math need the Axiom of Infinity? 3Is the long line paracompact? 22Can a vector space over an infinite field be a finite union of proper subspaces?