Core Concepts
Aharoni's rainbow cycle conjecture holds up to an additive constant.
Abstract
The content discusses the proof and analysis of Aharoni's rainbow cycle conjecture. It starts by introducing the conjecture proposed by Aharoni in 2017, a generalization of the Caccetta-Häggkvist conjecture. The paper proves that Aharoni's conjecture holds up to an additive constant for fixed r values. It delves into various theorems, results, and proofs related to edge-colored graphs, digraphs, and rainbow cycles. The content is structured into sections covering preliminaries, many non-stars case, few non-stars case, acknowledgments, and references.
Stats
For each fixed r ⩾1, there exists a constant αr ∈O(r5 log2 r) such that if G is a simple n-vertex edge-colored graph with n color classes of size at least r, then G contains a rainbow cycle of length at most n/r + αr.
The r = 3 case is still open, but the following approximate result was obtained by Clinch et al. [4].
Let c = 1011 and G be a simple n-vertex edge-colored graph with n color classes of size at least cr. Then G contains a rainbow cycle of length at most ⌈n/r⌉.
Quotes
"Let D be a simple n-vertex digraph with minimum out-degree at least r. Then D contains a directed cycle of length at most ⌈n/r⌉." - Conjecture 1.1 ([3])
"Let G be a simple n-vertex edge-colored graph with n color classes of size at least 2. Then G contains a rainbow cycle of length at most ⌈n/2⌉." - Theorem 1.4 ([5])