English

Random Latin squares and 2-dimensional expanders

Combinatorics 2013-07-16 v1

Abstract

Let X be a 2-dimensional simplicial complex. The degree of an edge e is the number of 2-faces of X containing e. The complex X is an \epsilon-expander if the coboundary d_1(\phi) of every Z_2-valued 1-cochain \phi \in C^1(X;Z_2) satisfies |support(d_1(\phi))| \geq \epsilon |\supp(\phi+d_0(\psi))| for some 0-cochain \psi. Using a new model of random 2-complexes we show the existence of an infinite family of 2-dimensional \epsilon-expanders with maximum edge degree d, for some fixed \epsilon>0 and d.

Keywords

Cite

@article{arxiv.1307.3582,
  title  = {Random Latin squares and 2-dimensional expanders},
  author = {Alexander Lubotzky and Roy Meshulam},
  journal= {arXiv preprint arXiv:1307.3582},
  year   = {2013}
}

Comments

20 pages

R2 v1 2026-06-22T00:50:47.089Z