Urn models, Markov chains and random walks in cosmological topologically massive gravity at the critical point

We discuss stochastic processes in the logarithmic sector of critical cosmological topologically massive gravity. By applying a result obtained in our previous works, we show that the logarithmic sector can be modelled as an urn scheme, conceptualizing the random process occurring in the theory as an evolutionary process with a dynamical state space described in terms of the content of the urns. The urn process is then identified as the celebrated Hoppe urn model. In this context, the "special" ball in this P\'olya-like urn construction finds a nice interpretation as a point-like defect and gives a concrete perspective of defect propagation in the logarithmic sector of the theory. A Markov process encoded in the partition function is described. It is further shown that the structure of the Markov chain consisting of a sample space that is the set of permutations of $n$ elements, leads to a specific description of the chain in terms of a random walk on the symmetric group. We suggest that a possible holographic dual of LCFT could be a theory that takes into account non-equilibrium phenomena.

Comment: 9 pages, 2 figures