On Partial Barycentric Subdivision

On Barycentric Subdivision

Consider the barycentric subdivision which cuts a given triangle along its medians to produce six new triangles. Uniformly choosing one of them and iterating this procedure gives rise to a Markov chain. We show that almost surely, the triangles forming this chain become flatter and flatter in the sense that their isoperimetric values goes to infinity with time. Nevertheless, if the triangles ar...

Universality for Barycentric subdivision

The spectrum of the Laplacian of successive Barycentric subdivisions of a graph converges exponentially fast to a limit which only depends on the clique number of the initial graph and not on the graph itself. Announced in [40]), the proof uses now an explicit linear operator mapping the clique vector of a graph to the clique vector of the Barycentric refinement. The eigenvectors of its transpo...

Computing Solid Angles by Barycentric Subdivision ∗

Barycentric Subdivision and Isomorphisms of Groupoids

Given groupoids G and H as well as an isomorphism Ψ : Sd G∼= Sd Hbetween subdivisions, we construct an isomorphism P : G∼= H . If Ψ equals SdF forsome functor F , then the constructed isomorphism P is equal to F . It follows thatthe restriction of Sd to the category of groupoids is conservative. These results donot hold for arbitrary categories.

The Γ-vector of a Barycentric Subdivision

We prove that the γ-vector of the barycentric subdivision of a simplicial sphere is the f -vector of a balanced simplicial complex. The combinatorial basis for this work is the study of certain refinements of Eulerian numbers used by Brenti and Welker to describe the h-vector of the barycentric subdivision of a boolean complex.