Brandeis-Harvard-MIT-Northeastern

JOINT MATHEMATICS COLLOQUIUM


 
Lengths of Monotone Subsequences in a Mallows Permutation

 

Nayantara Bhatnagar

University of Delaware.
 

MIT

Thursday, November 6, 2014


 

Talk 4:30-5:15pm in E25-111 (followed by Elchanan Mossel's talk)

Tea at 4:00 p.m in E17-401


 
 

Abstract: The longest increasing subsequence (LIS) of a uniformly random permutation is a well studied problem. Vershik-Kerov and Logan-Shepp first showed that asymptotically the typical length of the LIS is 2sqrt(n). This line of research culminated in the work of Baik-Deift-Johansson who related this length to the Tracy-Widom distribution.

We study the length of the LIS and LDS of random permutations drawn from the Mallows measure, introduced by Mallows in connection with ranking problems in statistics. Under this measure, the probability of a permutation p in S_n is proportional to q^Inv(p) where q is a real parameter and Inv(p) is the number of inversions in p. We determine the typical order of magnitude of the LIS and LDS, large deviation bounds for these lengths and a law of large numbers for the LIS for various regimes of the parameter q.

This is joint work with Ron Peled.





Home Web page:  Alexandru I. Suciu   Comments to:  i.loseu@neu.edu  
Posted: October 19, 2014    URL: http://www.math.neu.edu/bhmn/Bhatnagar14.html