works on

From the 1 of 19 linked papers with an AI index.

activity
20242026
collaborators

19 papers

math.CO2026

Forcing monochromatic induced subgraphs

Sepehr Hajebi, Sophie Spirkl

The paper proves that for any number of colors and a collection of nontrivial graphs, a sufficiently large edge‑colored complete graph without a monochromatic induced copy of the c…

math.CO2026

A simple layered-wheel-like construction

Maria Chudnovsky, David Fischer, Sepehr Hajebi +2

In recent years, there has been significant interest in characterizing the induced subgraph obstructions to bounded treewidth and pathwidth. While this has recently been resolved f…

math.CO2026

Bull-free graphs and -boundedness

Sepehr Hajebi

A bull is a graph obtained from a four-vertex path by adding a vertex adjacent to the two middle vertices of the path. A graph is bull-free if no induced subgraph of is a b…

math.CO2026

Asymmetric induced saturation

Xinyue Fan, Sahab Hajebi, Sepehr Hajebi +1

For which graphs does there exist a graph with at least one edge and no induced subgraph isomorphic to , such that deleting any edge of creates an induced copy of $H…

math.CO2026

Tree-alpha and excluding finitely many graphs

Sepehr Hajebi, Sophie Spirkl

We prove that a hereditary graph class defined by finitely many excluded induced subgraphs has bounded tree- if and only if it is "-bounded" (th…

math.CO2026

Suns in triangle-free graphs of large chromatic number

Sepehr Hajebi, Sophie Spirkl

For an integer , a -sun is a graph obtained from a -vertex cycle by adding a degree-one neighbor for each vertex of . Trotignon asked whether every triangle-f…