3 papers
math.CO2025
Separable convex optimization over indegree polytopes
Nóra A. Borsik, Péter Madarasi
We study separable discrete convex optimization over indegree vectors of orientations of an undirected graph, focusing on the effect of imposing acyclicity. Since the extreme point…
math.CO2025
Vertex-ordering and arc-partitioning problems
Nóra A. Borsik, Péter Madarasi
We study vertex-ordering problems in loop-free digraphs subject to constraints on the left-going arcs, focusing on existence conditions and computational complexity. As an intrigui…
math.CO2025
Prefix-bounded matrices
Nóra A. Borsik, András Frank, Péter Madarasi +1
By unifying various earlier extensions of alternating sign matrices (ASMs), we introduce the notion of prefix-bounded matrices (PBMs). It is shown that the convex hull of these mat…