Abstract
We describe two constructions of (very) dense graphs which are edge disjoint unions of large induced matchings. The first construction exhibits graphs on N vertices with (N2) - o(N2) edges, which can be decomposed into pairwise disjoint induced matchings, each of size N1-o(1). The second construction provides a covering of all edges of the complete graph KN by two graphs, each being the edge disjoint union of at most N2-δ induced matchings, where δ > 0.076. This disproves (in a strong form) a conjecture of Meshulam, substantially improves a result of Birk, Linial and Meshulam on communicating over a shared channel, and (slightly) extends the analysis of Håstad and Wigderson of the graph test of Samorodnitsky and Trevisan for linearity. Additionally, our constructions settle a combinatorial question of Vempala regarding a candidate rounding scheme for the directed Steiner tree problem.
Original language | English (US) |
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Pages (from-to) | 1575-1596 |
Number of pages | 22 |
Journal | Journal of the European Mathematical Society |
Volume | 15 |
Issue number | 5 |
DOIs | |
State | Published - 2013 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- General Mathematics
- Applied Mathematics