Richard Mandel

activity

20162026

collaborators

4 papers

cs.FL2026

The complexity of downward closures of indexed languages

Richard Mandel, Corto Mascle, Georg Zetzsche

Indexed languages are a classical notion in formal language theory, which has attracted attention in recent decades due to its role in higher-order model checking: They are precise…

math.GR2023

Quadratic equations in metabelian Baumslag-Solitar groups

Richard Mandel, Alexander Ushakov

For a finitely generated group $G$ , the \emph{Diophantine problem} over $G$ is the algorithmic problem of deciding whether a given equation $W (z_{1}, z_{2}, \dots, z_{k}) = 1$ (perhaps res…

math.NT2022

The Diophantine problem for systems of algebraic equations with exponents

Richard Mandel, Alexander Ushakov

Consider the equation $q_{1} α^{x_{1}} + \dots + q_{k} α^{x_{k}} = q$ , with constants $α \in Q ∖ {0, 1}$ , $q_{1}, \dots, q_{k}, q \in Q$ and unknowns $x_1…

math.NT2016

Computing the Fixed Field of $Aut (F (x) / F)$