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We present a review of recent work on the statistical mechanics of non equilibrium processes based on the analysis of large deviations properties of microscopic systems. Stochastic lattice gases are non trivial models of such phenomena and…

Probability · Mathematics 2015-12-18 L. Bertini , A. De Sole , D. Gabrielli , G. Jona-Lasinio , C. Landim

The usual path integral formulation for scalar particles at finite density involves a sign problem, making numerical simulation impractical. We present alternative methods free of this difficulty. We apply these approaches to phi^4 theory…

High Energy Physics - Lattice · Physics 2008-11-26 Michael G. Endres

We consider an ultracold quantum degenerate gas in an optical lattice inside a cavity. This system represents a simple but key model for "quantum optics with quantum gases," where a quantum description of both light and atomic motion is…

Quantum Physics · Physics 2010-02-26 Igor B. Mekhov , Helmut Ritsch

We consider the Langevin dynamics of a many-body system of interacting particles in $d$ dimensions, in a very general setting suitable to model several out-of-equilibrium situations, such as liquid and glass rheology, active self-propelled…

Disordered Systems and Neural Networks · Physics 2019-03-22 Elisabeth Agoritsas , Thibaud Maimbourg , Francesco Zamponi

I briefly introduce the methods by which lattice QCD predictions for RHIC are obtained. Next I deal with lattice determinations of strangeness production and event-to-event fluctuations of conserved quantities. I also present a new…

High Energy Physics - Phenomenology · Physics 2011-07-19 Sourendu Gupta

We discuss the thermodynamics of the O(3) nonlinear sigma model in 1+1 dimensions at nonzero chemical potential (equivalent to a magnetic field). In its conventional field theory representation the model suffers from a sign problem. By…

High Energy Physics - Lattice · Physics 2016-12-07 Falk Bruckmann , Christof Gattringer , Thomas Kloiber , Tin Sulejmanpasic

A technique to simulate the grand canonical ensembles of interacting Bose gases is presented. Results are generated for many temperatures by averaging over energy-weighted stochastic paths, each corresponding to a solution of coupled…

Soft Condensed Matter · Physics 2009-11-10 P. D. Drummond , P. Deuar , K. V. Kheruntsyan

Although numerical simulation in lattice field theory is one of the most effective tools to study non-perturbative properties of field theories, it faces serious obstacles coming from the sign problem in some theories such as finite density…

High Energy Physics - Lattice · Physics 2008-12-19 Masahiro Imachi , Yasuhiko Shinno , Hiroshi Yoneyama

We define an infinite class of ``frustration-free'' interacting lattice quantum Hamiltonians for bosons, constructed such that their exact ground states have a density distribution specified by the Boltzmann weight of a corresponding…

Superconductivity · Physics 2025-09-11 Zhaoyu Han , Steven A. Kivelson

We compute deviations from ideal gas behavior of the pressure, density, and Bose-Einstein condensation temperature of a relativistic gas of charged scalar bosons caused by the current-current interaction induced by electromagnetic quantum…

High Energy Physics - Theory · Physics 2021-11-10 D. M. Reis , C. A. A. de Carvalho

In the complex Langevin approach to lattice simulations at nonzero density, zeroes of the fermion determinant lead to a meromorphic drift and hence a need to revisit the theoretical derivation. We discuss how poles in the drift affect the…

High Energy Physics - Lattice · Physics 2016-11-10 Gert Aarts , Erhard Seiler , Denes Sexty , Ion-Olimpiu Stamatescu

We develop an efficient sampling method by simulating Langevin dynamics with an artificial force rather than a natural force by using the gradient of the potential energy. The standard technique for sampling following the predetermined…

Statistical Mechanics · Physics 2015-09-30 M. Ohzeki , A. Ichiki

We solve the Gross-Pitaevskii equations for a dilute atomic gas in a magnetic trap, modeled by an anisotropic harmonic potential. We evaluate the wave function and the energy of the Bose Einstein condensate as a function of the particle…

Condensed Matter · Physics 2009-10-28 F. Dalfovo , S. Stringari

e formulate a method for studying the quantum field dynamics of ultracold Bose gases confined within optical lattice potentials, within the lowest Bloch-band Bose-Hubbard model. Our formalism extends the two-sites results of Phys. Rev.…

Other Condensed Matter · Physics 2009-11-11 I. Tikhonenkov , J. R. Anglin , A. Vardi

In this paper, we develop a numerical procedure for investigating the dynamics of trapped Bose gases based on the ZGN theory. The dynamical equations used consist of a generalized Gross-Pitaevskii equation for the condensate order parameter…

Statistical Mechanics · Physics 2007-05-23 B. Jackson , E. Zaremba

Interactions are known to have dramatic effects on bosonic gases in one dimension (1D). Not only does the ground state transform from a condensate-like state to an effective Fermi sea, but new fundamental excitations, which do not have any…

An analysis of the random lattice gas in the annealed limit is presented. The statistical mechanics of disordered lattice systems is briefly reviewed. For the case of the lattice gas with an arbitrary uniform interaction potential and…

Statistical Mechanics · Physics 2011-11-09 A. P. Vieira , L. L. Goncalves

We discuss stochastic phase-space methods within the truncated Wigner approximation and show explicitly that they can be used to solve non-equilibrium dynamics of bosonic atoms in one-dimensional traps. We consider systems both with and…

Quantum Gases · Physics 2012-09-25 J. Ruostekoski , A. D. Martin

The collective excitations of Bose condensates in anisotropic axially symmetric harmonic traps are investigated in the hydrodynamic and Thomas-Fermi limit. We identify an additional conserved quantity, besides the axial angular momentum and…

Condensed Matter · Physics 2009-10-30 Martin Fliesser , András Csordás , Péter Szépfalusy , Robert Graham

We simulate three experimental methods which could be realized in the laboratory to probe the band excitation energies and the momentum distribution of a Bose-Einstein condensate inside an optical lattice. The values of the excitation…

Statistical Mechanics · Physics 2009-10-31 M. L. Chiofalo , S. Succi , M. P. Tosi