An upper bound for the size of a $k$-uniform intersecting family with covering number $k$

TL;DR

This paper establishes a new asymptotic upper bound for the maximum size of a $k$-uniform intersecting family with covering number $k$, improving previous bounds and narrowing the gap in combinatorial extremal theory.

Contribution

The paper proves that the maximum size $r(k)$ of such families is asymptotically at most $(1+o(1))k^{k-1}$, refining existing bounds.

Findings

Established $r(k) \\leq (1 + o(1)) k^{k-1}$ as an upper bound.

Improved understanding of the extremal size of intersecting families with covering number $k$.

Narrowed the asymptotic gap between known lower and upper bounds.

Abstract

Let $r(k)$ denote the maximum number of edges in a $k$-uniform intersecting family with covering number $k$. Erd\H{o}s and Lov\'asz proved that $ \lfloor k! (e-1) \rfloor \leq r(k) \leq k^k.$ Frankl, Ota, and Tokushige improved the lower bound to $r(k) \geq \left( k/2 \right)^{k-1}$, and Tuza improved the upper bound to $r(k) \leq (1-e^{-1}+o(1))k^k$. We establish that $ r(k) \leq (1 + o(1)) k^{k-1}$.