Title
On the presence of periodic configurations in Turing machines and in counter machines
Abstract
A configuration of a Turing machine is given by a tape content together with a particular state of the machine. Petr Kůrka has conjectured that every Turing machine--when seen as a dynamical system on the space of its configurations--has at least one periodic orbit. In this paper, we provide an explicit counterexample to this conjecture. We also consider counter machines and prove that, in this case, the problem of determining if a given machine has a periodic orbit in configuration space is undecidable.
Year
DOI
Venue
2002
10.1016/S0304-3975(01)00382-6
Theor. Comput. Sci.
Keywords
DocType
Volume
tape content,counter machine,Turing machine,periodic configuration,dynamical system,periodic orbit,explicit counterexample,particular state,Petr K,configuration space
Journal
289
Issue
ISSN
Citations 
1
Theoretical Computer Science
14
PageRank 
References 
Authors
1.34
4
3
Name
Order
Citations
PageRank
Vincent D. Blondel11880184.86
Julien Cassaigne228240.80
Codrin Nichitiu3495.73