English

A Sharp Threshold for Spanning 2-Spheres in Random 2-Complexes

Combinatorics 2018-09-26 v4

Abstract

A Hamiltonian cycle in a graph is a spanning subgraph that is homeomorphic to a circle. With this in mind, it is natural to define a Hamiltonian d-sphere in a d-dimensional simplicial complex as a spanning subcomplex that is homeomorphic to a d-dimensional sphere. We consider the Linial-Meshulam model for random simplicial complexes, and prove that there is a sharp threshold at p=eγnp=\sqrt{\frac{e}{\gamma n}} for the appearance of a Hamiltonian 22-sphere in a random 22-complex, where γ=44/33\gamma = 4^4/3^3.

Keywords

Cite

@article{arxiv.1609.09837,
  title  = {A Sharp Threshold for Spanning 2-Spheres in Random 2-Complexes},
  author = {Zur Luria and Ran J. Tessler},
  journal= {arXiv preprint arXiv:1609.09837},
  year   = {2018}
}

Comments

Main changes from last version: An explanation of the proof structure was added as a subsection in the introduction. A computational mistake in Lemma 4.5 was corrected, and a result some constants throughout the proof had to be modified (in the definition of good graph, in the final estimation) . Some other minor corrections

R2 v1 2026-06-22T16:06:59.361Z