MathOverflow

A structure is rigid if it has no nontrivial automorphisms.
A structure is second-order Leibnizian if every two distinct elements are distinguishable by a second-order formula without parameters (i.e., for $a ≠ b$ there exists $ψ(x)$ such that $M ⊨ ψ(a) ∧ ¬ψ(b)$)....

I am studying the behavior of lattice points inside convex polytopes under linear transformations. Let $P\subset \mathbf R^n$ be a convex polytope with vertices in $\mathbf Z^n$, and let $T:\mathbf R^n \to\mathbf R^n$ be a linear endomorphism whose associated...

Consider $\mathbb{R}^n$ with coordinates $(y^1,\ldots,y^n)$ and a function $D(y)$ that is smooth (even analytic if it really helps) away from all the partial diagonals $y^\mu = y^\nu$ (not assuming anything specific on the diagonals). Denoting $\partial...

I hope this is appropriate for mathoverflow. For every prime $p$, the valuation of $\mathbb{Q}_p$ can extend to $\overline{\mathbb{Q}_p}$ uniquely. And $\overline{\mathbb{Q}_p}$ is isomorphic to $\mathbb{C}$ as abstract fields since they have the same...