Displaying similar documents to “Bergman complexes, Coxeter arrangements, and graph associahedra.”

On the Betti numbers of the real part of a three-dimensional torus embedding

Jan Ratajski (1993)

Colloquium Mathematicae

Similarity:

Let X be the three-dimensional, complete, nonsingular, complex torus embedding corresponding to a fan S ⊆ ℝ 3 and let V be the real part of X (for definitions see [1] or [3]). The aim of this note is to give a simple combinatorial formula for calculating the Betti numbers of V.

Fundamental groups of some special quadric arrangements.

Meirav Amram, Mina Teicher (2006)

Revista Matemática Complutense

Similarity:

Continuing our work on the fundamental groups of conic-line arrangements (Amram et al., 2003), we obtain presentations of fundamental groups of the complements of three families of quadric arrangements in P. The first arrangement is a union of n conics, which are tangent to each other at two common points. The second arrangement is composed of n quadrics which are tangent to each other at one common point. The third arrangement is composed of n quadrics, n-1 of them are tangent to the...