activity
20242026
collaborators

7 papers

math.CO2026

A sharp extension of Halin's removable-edge theorem to matchings

Hojin Chu

A subgraph of a -connected graph is called \emph{-removable} if remains -connected. Halin proved that every -connected graph with has…

math.CO2026

Minimum degree conditions for removable matchings in -connected graphs

Hojin Chu, Ringi Kim, Boram Park

In 1969, Halin proved that every -connected graph with minimum degree at least contains an edge such that is -connected. As an edge is a matching of size…

math.CO2026

On 2-connected graphs without cycles of length 1 modulo 3

Yandong Bai, Hojin Chu, Binlong Li +2

Burr and Erdős conjectured in 1976 that for all integers such that contains an even integer, every -vertex graph without cycles of length $\el…

math.CO2025

Connectivity keeping trees in triangle-free graphs

Hojin Chu, Shinya Fujita, Boram Park +1

In 2012, Mader conjectured that for any tree of order , every -connected graph with minimum degree at least contains a subtree $T'\c…

math.CO2025

On -connected graphs avoiding cycles of length modulo

Hojin Chu, Boram Park, Homoon Ryu

For two integers and , an -cycle means a cycle of length such that . In 1977, Bollobás proved a conjecture of Burr and Er…

math.CO2025

Linear-Time Computation of the Frobenius Normal Form for Symmetric Toeplitz Matrices via Graph-Theoretic Decomposition

Hojin Chu, Homoon Ryu

We introduce a linear-time algorithm for computing the Frobenius normal form (FNF) of symmetric Toeplitz matrices by utilizing their inherent structural properties through a graph-…