Logo image
An abelian periodicity lemma
Journal article   Peer reviewed

An abelian periodicity lemma

J. Simpson
Theoretical Computer Science, Vol.656(B), pp.249-255
2015
url
Link to Published Version *Subscription may be requiredView

Abstract

We write x≺yx≺y when x and y are vectors with each element of x less than or equal to the corresponding element of y and P(w)P(w) for the Parikh vector of a word w. A word w has abelian period p if it has the form u0u1⋯umum+1u0u1⋯umum+1 with |u0|≤p|u0|≤p, |ui|=p|ui|=p for i=1,…mi=1,…m and |um+1|≤p|um+1|≤p, and P(u0)≺PP(u0)≺P, P(u0)=PP(u0)=P for i=1,…,mi=1,…,m and P(um+1)≺PP(um+1)≺P for some vector P. Blanchet-Sadri et al. conjectured that if a word has abelian periods pd and qd , where gcd⁡(p,q)=1gcd⁡(p,q)=1, and length at least 2pqd−12pqd−1 then the number of distinct letters appearing in the word is at most d , and that under certain conditions the bound may be reduced to 2pqd−22pqd−2. We prove their conjecture.

Details

Metrics

InCites Highlights

These are selected metrics from InCites Benchmarking & Analytics tool, related to this output

Citation topics
9 Mathematics
9.28 Pure Maths
9.28.534 Dynamical Systems
Web Of Science research areas
Computer Science, Theory & Methods
ESI research areas
Computer Science
Logo image