3 papers
math.AG2026
Any-dimensional Positivstellensätze for symmetric functions
Sebastian Debus, Robin Schabert
Positivstellensätze provide certificates of positivity for polynomials. Extending these certificates to symmetric functions, uniformly across all dimensions, presents structural ch…
cs.SC2025
Deciding Connectivity in Symmetric Semi-Algebraic Sets
Cordian. Riener, Robin Schabert, Thi Xuan Vu
A semi-algebraic set is a subset of defined by a finite collection of polynomial equations and inequalities. In this paper, we investigate the problem of determining…
math.AG2024
Constructively describing orbit spaces of finite groups by few inequalities
Philippe Moustrou, Cordian Riener, Robin Schabert
Let be a finite group acting linearly on . A celebrated Theorem of Procesi and Schwarz gives an explicit description of the orbit space as a…