Jagdeep Singh

activity

20202026

collaborators

6 papers

math.CO2026

Degeneracy: From Graphs to Matroids

Allan Bickle, James Dylan Douthitt, Wayne Ge +1

A graph is $k$ -degenerate if every subgraph has a vertex of degree at most $k$ . We extend this notion to matroids, defining a loopless matroid $M$ to be $k$ -degenerate if every res…

math.CO2026

The connected binary matroids with a pair of elements in no non-spanning circuits

Wayne Ge, James Oxley, Jagdeep Singh

Let $M$ be a simple connected binary matroid, and let $e$ and $f$ be distinct elements of $M$ . It is well known that, when the only circuits containing $e$ are spanning, $M$ is a c…

math.CO2022

Cographs and 1-sums

Jagdeep Singh

A graph that can be generated from $K_{1}$ using joins and 0-sums is called a cograph. We define a sesquicograph to be a graph that can be generated from $K_{1}$ using joins, 0-sums, a…

math.CO2021

The smallest class of binary matroids closed under direct sums and complements

James Oxley, Jagdeep Singh

The class of cographs or complement-reducible graphs is the class of graphs that can be generated from $K_{1}$ using the operations of disjoint union and complementation. By analogy,…

math.CO2021

Generalizing Cographs to 2-Cographs

James Oxley, Jagdeep Singh

A graph in which every connected induced subgraph has a disconnected complement is called a cograph. Such graphs are precisely the graphs that do not have the 4-vertex path as an i…

math.CO2020

Elastic elements in 3-connected matroids

George Drummond, Zachary Gershkoff, Susan Jowett +2

It follows by Bixby's Lemma that if $e$ is an element of a $3$ -connected matroid $M$ , then either ${\rm co}(M\delete e)$, the cosimplification of $M\delete e$, or $si (M / e)$ ,…