S. Spirkl

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20132026

most citedInduced subgraphs and tree decompositions IV. (Even hole, diamond, pyramid)-free graphs

12 citations · 147 across the 77 of their papers we have counts for

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Showing 2025 · math.COShow all

4 papers · 2 filters

math.CO2025

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.CO2025

Halfway to induced saturation for even cycles

Xinyue Fan, Sahab Hajebi, Sepehr Hajebi +1

For graphs $G$ and $H$ , we say that $G$ is $H$ -free if no induced subgraph of $G$ is isomorphic to $H$ , and that $G$ is $H$ -induced-saturated if $G$ is $H$ -free but removing or add…

math.CO2025

Suns in triangle-free graphs of large chromatic number

Sepehr Hajebi, Sophie Spirkl

For an integer $t \geq 4$ , a $t$ -sun is a graph obtained from a $t$ -vertex cycle $C$ by adding a degree-one neighbor for each vertex of $C$ . Trotignon asked whether every triangle-f…

math.CO2025

Induced subgraphs and tree decompositions XIX. Thetas and forests

Maria Chudnovsky, Julien Codsi, Sepehr Hajebi +1

Let $H$ be a graph and let $C$ be a hereditary class of theta-free graphs such that $H \in / C$ . We prove that if (a) $H$ is a forest; and (b) $C$ exc…