Title
Phase transition in cohomology groups of non-uniform random simplicial complexes
Abstract
We consider a generalised model of a random simplicial complex, which arises from a random hypergraph. Our model is generated by taking the downward-closure of a nonuniform binomial random hypergraph, in which for each k, each set of k + 1 vertices forms an edge with some probability p(k) independently. As a special case, this contains an extensively studied model of a (uniform) random simplicial complex, introduced by Meshulam and Wallach [Random Structures & Algorithms 34 (2009), no. 3, pp. 408-417]. We consider a higher-dimensional notion of connectedness on this new model according to the vanishing of cohomology groups over an arbitrary abelian group R. We prove that this notion of connectedness displays a phase transition and determine the threshold. We also prove a hitting time result for a natural process interpretation, in which simplices and their downward-closure are added one by one. In addition, we determine the asymptotic behaviour of cohomology groups inside the critical window around the time of the phase transition.
Year
DOI
Venue
2022
10.37236/10607
ELECTRONIC JOURNAL OF COMBINATORICS
DocType
Volume
Issue
Journal
29
3
ISSN
Citations 
PageRank 
1077-8926
0
0.34
References 
Authors
0
4
Name
Order
Citations
PageRank
Cooley Oliver100.34
Del Giudice Nicola200.34
Mihyun Kang316329.18
Sprüssel Philipp400.34