arXiv subjects

Eszter Szabó

Publications and source records attributed to Eszter Szabó.

3 recordsLinked to original sources

arXiv2026

Odd and Even Harder Problems on Cycle-Factors

For a graph (undirected or directed), a cycle-factor is a collection of vertex-disjoint cycles covering the entire vertex set. Cycle-factors subject to parity constraints arise naturally in the study of structural graph theory and algorithmic complexity. In this work, we study four variants of the problem of finding a cycle-factor subject to the following parity constraints: (1) all cycles are odd, (2) all cycles are even, (3) at least one cycle is odd, and (4) at least one cycle is even. We show that all the variants of the problem are NP-complete both in undirected and directed graphs, even if each vertex is incident to at most three edges. We also prove that the first two variants are NP-complete even for planar directed graphs.

cs.DS↗

arXiv2026

Quantum Wasserstein isometries of the $n$-qubit state space: a Wigner-type result

We determine the isometry group of the $n$-qubit state space with respect to the quantum Wasserstein distance induced by the so-called symmetric transport cost for all $n \in \mathbb{N}.$ It turns out that the isometries are precisely the Wigner symmetries, that is, the unitary or anti-unitary conjugations.

math-ph↗

arXiv2023

Balanced Submodular Flows

This paper examines the Balanced Submodular Flow Problem, that is the problem of finding a feasible submodular flow minimizing the difference between the flow values along the edges. A min-max formula is given to the problem and an algorithm is presented to solve it using $O(m^2)$ submodular function minimizations. Then, these result are extended to the weighted version of the problem. Finally, the Balanced Integer Submodular Flow Problem is discussed.

math.OC↗