Phase Transitions in Hard-core Models

Speaker: 

Kavita Ramanan

Affiliation: 

Brown University
Department of Applied Mathematics
182, George Street
Providence, RI 02912
United States of America

Time: 

Thursday, 21 December 2017, 16:00 to 17:00

Venue: 

Organisers: 

The standard hard-core model on a locally finite graph describes a family of Gibbs specifications, parameterized by the so-called activity parameter.  An important problem is to determine when the model has a unique Gibbs measure and when it exhibits a phase transition (that is, has multiple Gibbs measures).  Such models arise in combinatorics, statistical physics and communication networks, and recent work has uncovered  interesting connections between phase transitions in these models and the hardness of various counting problems. We will describe phase transition properties of the hard-core model and its various avatars, including a continuous version of the model and describe some interesting consequences.