10 citations · 23 across the 8 of their papers we have counts for
7 papers · 1 filter
Reverse Lexicographic and Lexicographic Shifting
Eric Babson, Isabella Novik, Rekha R. Thomas
A short new proof of the fact that all shifted complexes are fixed by reverse lexicographic shifting is given. A notion of lexicographic shifting, $Δ_{\lex}$ -- an operation that t…
A Homotopy Theory for Graphs
E. Babson, H. Barcelo, M. de Longueville +1
The recently introduced A-homotopy groups for graphs are investigated. The main concern of the present article is the construction of an infinite cell complex, the homotopy groups…
Proof of the Lovasz Conjecture
Eric Babson, Dmitry N. Kozlov
To any two graphs G and H one can associate a cell complex Hom(G,H) by taking all graph multihomorphisms from G to H as cells. In this paper we prove the Lovasz Conjecture which st…
Complexes of graph homomorphisms
Eric Babson, Dmitry N. Kozlov
is a polyhedral complex defined for any two undirected graphs and . This construction was introduced by Lovász to give lower bounds for chromatic numbers of graph…
Topological obstructions to graph colorings
Eric Babson, Dmitry N. Kozlov
For any two graphs and Lovász has defined a cell complex having in mind the general program that the algebraic invariants of these complexes should provide obstr…
Symmetric iterated Betti numbers
Eric Babson, Isabella Novik, Rekha Thomas
We define a set of invariants of a homogeneous ideal in a polynomial ring called the symmetric iterated Betti numbers of . For , the Stanley-Reisner ideal of a simplici…