activity
20052026
most citedA structure theorem for graphs with no cycle with a unique chord and its consequences

56 citations · 715 across the 68 of their papers we have counts for

collaborators

70 papers

math.CO2026

(Even hole, triangle)-free graphs revisited

Beatriz Martins, Nicolas Trotignon

We revisit a classical paper about (even hole, triangle)-free graphs [Conforti, Cornuéjols, Kapoor and Vu\v sković, Triangle-free graphs that are signable without even holes, Journ…

cs.CC2025

Induced Disjoint Paths Without an Induced Minor

Pierre Aboulker, Édouard Bonnet, Timothé Picavet +1

We exhibit a new obstacle to the nascent algorithmic theory for classes excluding an induced minor. We indeed show that on the class of string graphs -- which avoids the 1-subdivis…

math.CO2024

Unavoidable induced subgraphs in graphs with complete bipartite induced minors

Maria Chudnovsky, Meike Hatzel, Tuukka Korhonen +2

We prove that if a graph contains the complete bipartite graph as an induced minor, then it contains a cycle of length at most~12 or a theta as an induced subgraph. W…

math.CO2024

Induced Minor Models. I. Structural Properties and Algorithmic Consequences

Nicolas Bousquet, Clément Dallard, Maël Dumas +4

A graph is said to be an induced minor of a graph if can be obtained from by a sequence of vertex deletions and edge contractions. Equivalently, is an induced m…

math.CO2024

Graphs without a 3-connected subgraph are 4-colorable

Édouard Bonnet, Carl Feghali, Tung Nguyen +4

In 1972, Mader showed that every graph without a 3-connected subgraph is 4-degenerate and thus 5-colorable}. We show that the number 5 of colors can be replaced by 4, which is best…

math.CO2023★ 2 cited

A tamed family of triangle-free graphs with unbounded chromatic number

Édouard Bonnet, Romain Bourneuf, Julien Duron +3

We construct a hereditary class of triangle-free graphs with unbounded chromatic number, in which every non-trivial graph either contains a pair of non-adjacent twins or has an edg…

math.CO2022★ 1 cited

When all holes have the same length

Jake Horsfield, Myriam Preissmann, Cléophée Robin +3

For every integer , we give a structural description of the class of graphs whose chordless cycles of length at least 4 all have length .

math.CO2021★ 2 cited

Burling graphs revisited, part III: Applications to -boundedness

Pegah Pournajafi, Nicolas Trotignon

The Burling sequence is a sequence of triangle-free graphs of unbounded chromatic number. The class of Burling graphs consists of all the induced subgraphs of the graphs of this se…

math.CO2021★ 3 cited

Graphs with all holes the same length

Linda Cook, Jake Horsfield, Myriam Preissmann +5

A graph is "-holed" if all its induced cycles of length at least four have length exactly . We give a complete description of the -holed graphs for each $\ell\ge…

math.CO2021

Burling graphs revisited, part II: Structure

Pegah Pournajafi, Nicolas Trotignon

The Burling sequence is a sequence of triangle-free graphs of increasing chromatic number. Any graph which is an induced subgraph of a graph in this sequence is called a Burling gr…

math.CO2021★ 6 cited

Burling graphs revisited, part I: New characterizations

Pegah Pournajafi, Nicolas Trotignon

The Burling sequence is a sequence of triangle-free graphs of increasing chromatic number. Each of them is isomorphic to the intersection graph of a set of axis-parallel boxes in $…

cs.DM2020★ 3 cited

On the tree-width of even-hole-free graphs

Pierre Aboulker, Isolde Adler, Eun Jung Kim +2

The class of all even-hole-free graphs has unbounded tree-width, as it contains all complete graphs. Recently, a class of (even-hole, )-free graphs was constructed, that still…

cs.DM2020

A class of graphs with large rankwidth

Chính Hoàng, Nicolas Trotignon

We describe several graphs with arbitrarily large rankwidth (or equivalently with arbitrarily large cliquewidth). Korpelainen, Lozin, and Mayhill [Split permutation graphs, Graphs…

math.CO2020★ 6 cited

Graphs with polynomially many minimal separators

Tara Abrishami, Maria Chudnovsky, Cemil Dibek +3

We show that graphs that do not contain a theta, pyramid, prism, or turtle as an induced subgraph have polynomially many minimal separators. This result is the best possible in the…

cs.DM2020★ 5 cited

(Theta, triangle)-free and (even hole, )-free graphs. Part 2 : bounds on treewidth

Marcin Pilipczuk, Ni Luh Dewi Sintiari, Stéphan Thomassé +1

A {\em theta} is a graph made of three internally vertex-disjoint chordless paths , , of length at least~2 and such that no edge…

cs.DM2019★ 3 cited

Maximum independent sets in (pyramid, even hole)-free graphs

Maria Chudnovsky, Stéphan Thomassé, Nicolas Trotignon +1

A \emph{hole} in a graph is an induced cycle with at least 4 vertices. A graph is \emph{even-hole-free} if it does not contain a hole on an even number of vertices. A \emph{pyramid…

math.CO2019★ 7 cited

The (theta, wheel)-free graphs Part IV: induced paths and cycles

Marko Radovanović, Nicolas Trotignon, Kristina Vušković

A hole in a graph is a chordless cycle of length at least 4. A theta is a graph formed by three internally vertex-disjoint paths of length at least 2 between the same pair of disti…

cs.DM2019★ 1 cited

On the complexity of colouring antiprismatic graphs

Myriam Preissmann, Cléophée Robin, Nicolas Trotignon

A graph G is prismatic if for every triangle T of G, every vertex of G not in T has a unique neighbour in T. The complement of a prismatic graph is called \emph{antiprismatic}. The…

math.CO2019

The independent set problem is FPT for even-hole-free graphs

Edin Husic, Stephan Thomasse, Nicolas Trotignon

The class of even-hole-free graphs is very similar to the class of perfect graphs, and was indeed a cornerstone in the tools leading to the proof of the Strong Perfect Graph Theore…

cs.DM2019★ 6 cited

(Theta, triangle)-free and (even hole, )-free graphs. Part 1 : Layered wheels

Ni Luh Dewi Sintiari, Nicolas Trotignon

We present a construction called layered wheel. Layered wheels are graphs of arbitrarily large treewidth and girth. They might be an outcome for a possible theorem characterizing g…

math.CO2019

Coloring graphs with no induced subdivision of

Louis Esperet, Nicolas Trotignon

Let be the 5-vertex graph obtained from , the complete graph on four vertices, by subdividing one edge precisely once (i.e. by replacing one edge by a path on three ve…

cs.DM2018★ 3 cited

Connected greedy colouring in claw-free graphs

Ngoc Khang Le, Nicolas Trotignon

An ordering of the vertices of a graph is \emph{connected} if every vertex (but the first) has a neighbor among its predecessors. The greedy colouring algorithm of a graph with a c…

math.CO2017★ 4 cited

The (theta, wheel)-free graphs Part III: cliques, stable sets and coloring

Marko Radovanović, Nicolas Trotignon, Kristina Vušković

A hole in a graph is a chordless cycle of length at least 4. A theta is a graph formed by three paths between the same pair of distinct vertices so that the union of any two of the…

math.CO2017★ 7 cited

Triangle-free graphs that do not contain an induced subdivision of are 3-colorable

Maria Chudnovsky, Chun-Hung Liu, Oliver Schaudt +3

We show that triangle-free graphs that do not contain an induced subgraph isomorphic to a subdivision of K4 are 3-colorable. This proves a conjecture of Trotignon and Vuskovic.