
Combinatorial Topology and Applications
International Workshop
Date: Friday, September 12th, 2014,
Time: 09:0014:00
Place: Universität Bremen, MZH 7200
Speakers:
Emanuele Delucchi (Université de Fribourg)
Michał Adamaszek (MPI Informatik, Saarbrücken)
Dmitry FeichtnerKozlov (Universität Bremen)
Schedule:
09:0010:00  Emanuele Delucchi (Université de Fribourg) 
Recent developments in toric arrangements 
The study of toric arrangements is rooted in the literature in both its topological
(since at least Looienga in 1993) and combinatorial aspects (e.g., Ehrenborg, Readdy
and Slone 2009). Recent work of De Concini, Procesi and Vergne provided a fresh
impulse towards a comprehensive study of this subject, viewed as a generalization
of the successful theory of hyperplane (or subspace) arrangements in vector spaces.
Out of this impulse grew many new results and techniques, concerning both topology
and in combinatorics, which I will try to survey with an eye towards setting up a
general combinatorialtopological framework which might lead to the treatment of
even more general types of arrangements. Some of the results I will present have
been obtained in joint works with Karim Adiprasito, Filippo Callegaro, Giacomo
d'Antonio or Sonja Riedel.


10:3011:30  Michał Adamaszek (MPI Informatik, Saarbrücken) 
Arcs on a circle 
For any finite collection of arcs on a circle
we show that its nerve is homotopy equivalent to an odd sphere or a
wedge of even spheres. A key role is played by certain simplicial
complexes N(n,k) with cyclic symmetry. I will mention some results
and conjectures about the topology of these complexes, their relation
to the classical cyclic polytopes and an unexpected connection to an
extremal problem about the gaps between roots of trigonometric
polynomials. Joint with Henry Adams, Florian Frick,
Christopher Peterson, Corrine Previte. 

11:4512:45  Dmitry FeichtnerKozlov (Universität Bremen) 
Conguration spaces arising in distributed computing 
In this talk we shall describe a family of simplicial complexes, called
protocol complexes, which arise naturally as some of the central objects in the
eld of theoretical distributed computing. These complexes give a
description of the totality of all possible executions of distributed
protocols in a xed computational model. They are the natural
analog of conguration spaces in this context. Part of the talk will
be based in the recent book "Distributed Computing through
Combinatorial Topology", joint with M. Herlihy and S. Rajsbaum. 
