Quick search Find article
Quick search
Find article

On the Brownian gas: a field theory with a Poissonian ground state

Andrea Velenich1, Claudio Chamon1, Leticia F Cugliandolo2 and Dirk Kreimer3,4

Show affiliations


As a first step toward a successful field theory of Brownian particles in interaction, we study exactly the non-interacting case, its combinatorics and nonlinear time-reversal symmetry. Even though the particles do not interact, the field theory contains an interaction term: the vertex is the hallmark of the original particle nature of the gas and it enforces the constraint of a strictly positive density field, as opposed to a Gaussian free field. We compute exactly all the n-point density correlation functions, determine non-perturbatively the Poissonian nature of the ground state and emphasize the futility of any coarse-graining assumption for the derivation of the field theory. We finally verify explicitly, on the n-point functions, the fluctuation–dissipation theorem implied by the time-reversal symmetry of the action.


PACS

05.40.Jc Brownian motion

82.70.Dd Colloids

02.50.Ng Distribution theory and Monte Carlo studies

02.10.Ox Combinatorics; graph theory

82.70.Kj Emulsions and suspensions

MSC

60G15 Gaussian processes

05Cxx Graph theory (For applications of graphs, see 68R10, 90C35, 94C15)

60J65 Brownian motion (See also 58J65)

Subjects

Soft matter, liquids and polymers

Mathematical physics

Computational physics

Statistical physics and nonlinear systems

Chemical physics and physical chemistry

Dates

Issue 23 (13 June 2008)

Received 21 February 2008, in final form 23 April 2008

Published 19 May 2008



View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.