Clique Decompositions in Random Graphs via Refined Absorption

Abstract

We prove that if $p\ge n^{-\frac{1}{3}+β}$ for some $β> 0$, then asymptotically almost surely the binomial random graph $G(n,p)$ has a $K_3$-packing containing all but at most $n + O(1)$ edges. Similarly, we prove that if $d \ge n^{\frac{2}{3}+β}$ for some $β> 0$ and $d$ is even, then asymptotically almost surely the random $d$-regular graph $G_{n,d}$ has a triangle decomposition provided $3 \mid d \cdot n$. We also show that $G(n,p)$ admits a fractional $K_3$-decomposition for such a value of $p$. We prove analogous versions for a $K_q$-packing of $G(n,p)$ with $p\ge n^{-\frac{1}{q+0.5}+β}$ and leave of $(q-2)n+O(1)$ edges, for $K_q$-decompositions of $G_{n,d}$ with $(q-1)~|~d$ and $d\ge n^{1-\frac{1}{q+0.5}+β}$ provided $q\mid d\cdot n$, and for fractional $K_q$-decompositions.

Theorems & Definitions (122)

• Conjecture 1.1: Yuster Yu07
• Conjecture 1.2: Yuster Yu07
• Theorem 1.3
• Theorem 1.4
• Theorem 1.5
• Theorem 1.6
• Definition 1.7: Absorber
• Definition 1.8: Maximum rooted density
• Definition 1.9: Maximum $2$-density
• Definition 1.10: Absorber rooted $2$-density threshold