collaborators

7 papers

math.CO2026

Crossing tournaments are polynomially -bounded

Lila Crew, Xinyue Fan, Hidde Koerts +2

Given a tournament , Aboulker, Aubian, Charbit, and Lopes (2023) defined its clique number as the minimum clique number of a backedge graph of , and raised the que…

math.CO2026

Decomposing tournaments into comparability graphs

Pierre Aboulker, Logan Crew, Julien Duron +7

In this note, we introduce the \emph{partial order decomposition number} of a digraph , denoted , defined as the minimum integer such that $A(D)=A(P_1)\cup\cdots\cup…

math.CO2026

Homomorphism counting for immersion-closed classes is not isomorphism

Andrea Jiménez, Benjamin Moore, Daniel A. Quiroz +1

Lovász proved that two graphs and are isomorphic if for all graphs , where denotes the number of homomorphisms from to $G_…

math.CO2026

Characterizing Large Clique Number in Tournaments

Logan Crew, Xinyue Fan, Hidde Koerts +2

Aboulker, Aubian, Charbit, and Lopes (2023) defined the clique number of a tournament to be the minimum clique number of one of its backedge graphs. Here we show that if is a t…

math.CO2026

Flow-critical graphs

Arnbjörg Soffía Árnadóttir, Zdeněk Dvořák, Bernard Lidický +3

Lovász et al. proved that every -edge-connected graph has a nowhere-zero -flow. In fact, they proved a more technical statement which says that there exists a nowhere zero $…

math.CO2025

Smoothed analysis for graph isomorphism

Michael Anastos, Matthew Kwan, Benjamin Moore

There is no known polynomial-time algorithm for graph isomorphism testing, but elementary combinatorial "refinement" algorithms seem to be very efficient in practice. Some philosop…