9 Answers votes newest views recent 5What is the characteristic property of surjective submersions? 5Is a rhombus rigid on a sphere or torus? And generalizations. 7edges minus vertices 13Which Riemannian manifolds admit a finite dimensional transitive Lie group action? 42Demonstrating that rigour is important 5A question about a one-form on Riemannian manifold 2Is there a Whitney Embedding Theorem for non-smooth manifolds? 9Lie group actions and f-relatedness 22What are some correct results discovered with incorrect (or no) proofs?