activity
20242026
collaborators

8 papers

math.AG2026

Quadrature rules with few nodes supported on algebraic curves

Cordian Riener, Ettore Teixeira Turatti

We investigate quadrature rules for measures supported on real algebraic and rational curves, focusing on the {odd-degree} case \(2s-1\). Adopting an optimization viewpoint, we min…

math.AC2026

Symmetric and Isotypic Hilbert Series for Symmetric Ideals

Henri Breloer, Cordian Riener

An ideal in a polynomial ring is symmetric if it is invariant under any permutation of variables. In this paper, we define and study the symmetric and isotypic Hilbert series for s…

cs.CC2025

#P-hardness proofs of matrix immanants evaluated on restricted matrices

Istvan Miklos, Cordian Riener

We establish the -hardness of computing a broad class of immanants, even when restricted to specific categories of matrices. Concretely, we prove that computing -immanants…

math.AG2025

Slices of Stable Polynomials and Connections to the Grace-Walsh-Szegő theorem

Sebastian Debus, Cordian Riener, Robin Schabert

Univariate polynomials are called stable with respect to a domain if all of their roots lie in . We study linear slices of the space of stable univariate polynomials with re…

math.AG2025

Symbolic Computation with Symmetric Polynomials in Real Algebraic Geometry

Cordian Riener, Thi Xuan Vu

Symmetry plays a central role in accelerating symbolic computation involving polynomials. This chapter surveys recent developments and foundational methods that leverage the inhere…

math.OC2025

A semidefinite programming hierarchy for covering problems in discrete geometry

Cordian Riener, Jan Rolfes, Frank Vallentin

In this paper we present a new semidefinite programming hierarchy for covering problems in compact metric spaces. Over the last years, these kind of hierarchies were developed prim…