Tel Aviv University 
 
Dear all,
 
Next week will be the final meeting for the semester of the Horowitz
seminar on Probability, Ergodic Theory and Dynamical Systems at Tel
Aviv University. We are happy to have:
 
Speaker: Pascal Vanier, Hebrew University
Title: Characterizations of periods of multidimensional SFTs
 
Date: Monday, June 24
Time: 14:30
Place: Schreiber 309
 
Abstract:
In this talk, we will introduce several notions of periodicity for
higher dimensional shifts and give computational characterizations of
sets of periods of SFTs for some of them. We will in particular focus
on points with a finite orbit, the straightforward generalization of
periodicity from dimension 1. We will show that sets of periods of
multidimensional SFTs correspond exactly to the languages of the
computational complexity class NE (languages recognizable in
nondeterministic linear exponential time). In order to attain this
result we will first focus on the intermediate notion of horizontal
periodicity, whose characterization is easier to achieve.
 
Best regards,
   Ron
Seminar webpage:
 <http://www.math.tau.ac.il/~peledron/Horowitz_seminar/Horowitz_seminar.html>
 
---------------------------------------------------------
Technion Math Net-2 (TECHMATH2)
Editor: Michael Cwikel   <techm@math.technion.ac.il> 
Announcement from: Ron Peled   <peledron@post.tau.ac.il>