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We apply the Projected Gross-Pitaevskii equation (PGPE) formalism to the experimental problem of the shift in critical temperature $T_c$ of a harmonically confined Bose gas as reported in Gerbier \emph{et al.} [Phys. Rev. Lett. \textbf{92},…

Other Condensed Matter · Physics 2007-06-20 Matthew J. Davis , P. Blair Blakie

We develop an approximate formalism suitable for performing simulations of the thermal dynamics of interacting Bose gases. The method is based on the observation that when the lowest energy modes of the Bose field operator are highly…

Condensed Matter · Physics 2009-11-07 M. J. Davis , R. J. Ballagh , K. Burnett

We introduce a time-dependent projected Gross-Pitaevskii equation to describe a partially condensed homogeneous Bose gas, and find that this equation will evolve randomised initial wave functions to equilibrium. We compare our numerical…

Condensed Matter · Physics 2009-10-31 M. J. Davis , S. A. Morgan , K. Burnett

We demonstrate that the time-dependent projected Gross-Pitaevskii equation derived earlier [Davis, et al., J. Phys. B 34, 4487 (2001)] can represent the highly occupied modes of a homogeneous, partially-condensed Bose gas. We find that this…

Condensed Matter · Physics 2009-11-07 M. J. Davis , S. A. Morgan , K. Burnett

A classical fields approximation to the finite temperature microcanonical thermodynamics of weakly interacting Bose gas is applied to the idealized case of atoms confined in a box with periodic boundary conditions. We analyze in some detail…

Condensed Matter · Physics 2009-11-10 Miroslaw Brewczyk , Peter Borowski , Mariusz Gajda , Kazimierz Rzazewski

The mean-field properties of finite-temperature Bose-Einstein gases confined in spherically symmetric harmonic traps are surveyed numerically. The solutions of the Gross-Pitaevskii (GP) and Hartree-Fock-Bogoliubov (HFB) equations for the…

Statistical Mechanics · Physics 2009-10-31 T. Bergeman , D. L. Feder , N. L. Balazs , B. I. Schneider

We extend the Projected Gross Pitaevskii equation formalism of Davis et al. [Phys. Rev. Lett. \bf{87}, 160402 (2001)] to the experimentally relevant case of harmonic potentials. We outline a robust and accurate numerical scheme that can…

Other Condensed Matter · Physics 2015-06-24 P. Blair Blakie , Matthew J. Davis

The ergodic hypothesis asserts that a classical mechanical system will in time visit every available configuration in phase space. Thus, for an ergodic system, an ensemble average of a thermodynamic quantity can equally well be calculated…

Other Condensed Matter · Physics 2007-06-20 Matthew J. Davis , P. Blair Blakie

We develop formalism based on the projected Gross Pitaevskii equation to simulate the finite temperature collective mode experiments of Jin et al. [PRL 78, 764 (1997)]. We examine the $m=0$ and $m=2$ quadrupolar modes on the temperature…

Other Condensed Matter · Physics 2009-03-31 A. Bezett , P. B. Blakie

In this paper we describe a method for evolving the projected Gross-Pitaevskii equation (PGPE) for a Bose gas in a harmonic oscillator potential. The central difficulty in solving this equation is the requirement that the classical field is…

Computational Physics · Physics 2008-08-19 P. B. Blakie

We review c-field methods for simulating the non-equilibrium dynamics of degenerate Bose gases beyond the mean-field Gross-Pitaevskii approximation. We describe three separate approaches that utilise similar numerical methods, but have…

We present precise path-integral Monte-Carlo results for the thermodynamics of a homogeneous dilute Bose gas. Pressure and energy are calculated as a function of temperature both below and above the Bose-Einstein transition. Specifically,…

Quantum Gases · Physics 2023-10-23 Gabriele Spada , Sebastiano Pilati , Stefano Giorgini

The stochastic Gross-Pitaevskii equation and modified Popov theory are shown to provide an ab initio description of finite temperature, weakly-interacting two-dimensional Bose gas experiments. Using modified Popov theory, a systematic…

Quantum Gases · Physics 2013-05-30 S. P. Cockburn , N. P. Proukakis

Starting with a scalar field in a thermal bath and using the one loop quantum correction potential, we rewrite the Klein-Gordon equation in its thermodynamical representation and study the behavior of this scalar field due to temperature…

General Relativity and Quantum Cosmology · Physics 2014-02-04 T. Matos , A. Suárez

We consider a finite-temperature Bose-Einstein condensate in a quasi-two-dimensional trap containing a single precessing vortex. We find that such a configuration arises naturally as an ergodic equilibrium of the projected Gross-Pitaevskii…

Quantum Gases · Physics 2009-11-29 T. M. Wright , A. S. Bradley , R. J. Ballagh

The relaxation of a quantum field from a metastable state (false vacuum) to a stable one (true vacuum), also known as false vacuum decay, is a fundamental problem in quantum field theory and cosmology. We study this phenomenon using a…

Quantum Gases · Physics 2026-02-04 Paniyanchatha Moolayil Sivasankar , Franco Dalfovo , Alessio Recati , Arko Roy

In this paper, we mainly review recent results on mathematical theory and numerical methods for Bose-Einstein condensation (BEC), based on the Gross-Pitaevskii equation (GPE). Starting from the simplest case with one-component BEC of the…

Quantum Gases · Physics 2017-01-10 Weizhu Bao , Yongyong Cai

The achievement of Bose-Einstein condensation (BEC) in ultracold vapors of alkali atoms has given enormous impulse to the theoretical and experimental study of dilute atomic gases in condensed quantum states inside magnetic traps and…

Mathematical Physics · Physics 2017-11-21 Weizhu Bao

We study self-gravitating bosonic systems, candidates for dark-matter halos, by carrying out a suite of direct numerical simulations (DNSs) designed to investigate the formation of finitetemperature, compact objects in the three-dimensional…

Quantum Gases · Physics 2021-06-02 Akhilesh Kumar Verma , Rahul Pandit , Marc E. Brachet

We review the stochastic Gross-Pitaevskii approach for non-equilibrium finite temperature Bose gases, focussing on the formulation of Stoof; this method provides a unified description of condensed and thermal atoms, and can thus describe…

Quantum Gases · Physics 2017-08-23 Stuart P. Cockburn , Nick P. Proukakis
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