collaborators

8 papers

math.CO2026

Balanced-chromatic number and Hadwiger-like conjectures

Andrea Jiménez, Jessica McDonald, Reza Naserasr +2

Motivated by different characterizations of planar graphs and the 4-Color Theorem, several structural results concerning graphs of high chromatic number have been obtained. Toward…

math.CO2026

Winding number and circular coloring

Reza Naserasr, Cyril Pujol, Lujia Wang

In 1996, Youngs proved a surprising theorem that quadrangulations of the projective plane could never have chromatic number exactly 3. This sparked a lot of interest, and the resul…

math.CO2025

Extension of the Gyárfás-Sumner conjecture to signed graphs

Guillaume Aubian, Allen Ibiapina, Luis Kuffner +4

The balanced chromatic number of a signed graph G is the minimum number of balanced sets that cover all vertices of G. Studying structural conditions which imply bounds on the bala…

math.CO2025

Brooks' theorem for signed graphs with

Reza Naserasr, Huan Zhou

Circular -coloring of a signed graph is a mapping of its vertices to a circle of circumference such that: I. each pair of vertices with a negative connection is at…

math.CO2025

Colouring signed analogues of Kneser, Schrijver, and Borsuk graphs

Luis Kuffner, Reza Naserasr, Lujia Wang +3

The Kneser signed graph $\KS(n,k)$, , is the graph whose vertices are signed -subsets of (i.e. -subsets of such that $S\…

math.CO2025

Fractional balanced chromatic number and arboricity of planar (signed) graphs

Reza Naserasr, Lan Anh Pham, Cyril Pujol +1

A fractional coloring of a signed graph is an assignment of nonnegative weights to the balanced sets (sets which do not induce a negative cycle) such that each vertex has…