Localized Clique Bounds in Bounded-Degree and Bounded-Path Graphs
Abstract
Let $\mathcal{F}$ be a family of graphs. A graph is said to be $\mathcal{F}$-free if it contains no member of $\mathcal{F}$. The generalized Tur\'{a}n number $ex(n,H,\mathcal{F})$ denotes the maximum number of copies of a graph $H$ in an $n$-vertex $\mathcal{F}$-free graph, while the generalized edge Tur\'{a}n number $mex(m,H,\mathcal{F})$ denotes the maximum number of copies of $H$ in an $m$-edge $\mathcal{F}$-free graph. It is well known that if a graph has maximum degree $d$, then it is $K_{1,d+1}$-free. Wood \cite{wood} proved that $ex(n,K_t,K_{1,d+1}) \leq \frac{n}{d+1}\binom{d+1}{t}$. More recently, Chakraborty and Chen \cite{CHAKRABORTI2024103955} established analogous bounds for graphs with bounded maximum path length: $mex(m,K_t,P_{r+1}) \leq \frac{m}{\binom{r}{2}}\binom{r}{t}$. In this paper, we improve these bounds using the localization technique, based on suitably defined local parameters. Furthermore, we characterize the extremal graphs attaining these improved bounds.