김진하

Let $G$ be a graph on the vertex set $V$. A vertex subset $W\subset V$ is a cover of $G$ if $V\setminus W$ is an independent set of $G$, and $W$ is a non-cover of $G$ if $W$ is not a cover of $G$. The non-cover complex of $G$ is a simplicial complex …

Given a graph G=(V,E), the independence complex of G is the abstract simplicial complex I(G) on V whose faces are the independent sets of G. A graph is ternary if it does not contain an induced cycle of length divisible by three. Kalai and Meshulam conjectured that if G is ternary then the sum of the Betti numbers …

An independent dominating set of a graph, also known as a maximal independent set, is a set $S$ of pairwise non-adjacent vertices such that every vertex not in $S$ is adjacent to some vertex in $S$. We prove that for $\mathrm{\Delta }=4$ or $\mathrm{\Delta }\ge 6$, every connected $n$-vertex graph of maximum degree at most $\mathrm{\Delta }$ has …