Random walk on the simple symmetric exclusion process
In a joint work with Marcelo R. Hilário and Augusto Teixeira, we investigate the long-term behavior of a random walker evolving on top of the simple symmetric exclusion process (SSEP) at equilibrium. At each jump, the random walker is subject to a drift that depends on whether it is sitting on top of a particle or a hole. The asymptotic behavior is expected to depend on the density ρ in [0, 1] of the underlying SSEP.
Our first result is a law of large numbers (LLN) for the random walker for all densities ρ except for at most two values ρ− and ρ+ in [0, 1], where the speed (as a function of the density) possibly jumps from, or to, 0.
Second, we prove that, for any density corresponding to a non-zero speed regime, the fluctuations are diffusive and a Central Limit Theorem holds.
For the special case in which the density is 1/2 and the jump distribution on an empty site and on an occupied site are symmetric to each other, we prove a LLN with zero limiting speed.
Our main results extend to environments given by a family of independent simple symmetric random walks in equilibrium.
Date: 26 January 2022, 12:00 (Wednesday, 2nd week, Hilary 2022)
Venue: Mathematical Institute, Woodstock Road OX2 6GG
Venue Details: Room L3
Speaker: Daniel Kious (University of Bath)
Organising department: Department of Statistics
Organisers: Matthias Winkel (Department of Statistics, University of Oxford), Christina Goldschmidt (Department of Statistics, University of Oxford), James Martin (Department of Statistics, University of Oxford)
Organiser contact email address: winkel@stats.ox.ac.uk
Hosts: Matthias Winkel (Department of Statistics, University of Oxford), Christina Goldschmidt (Department of Statistics, University of Oxford), James Martin (Department of Statistics, University of Oxford)
Part of: Probability seminar
Booking required?: Not required
Audience: Members of the University only
Editors: James Martin, Matthias Winkel