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We consider the evolution of relativistic perturbations in the Einstein-de Sitter cosmological model, including second-order effects. The perturbations are considered in two different settings: the widely used synchronous gauge and the…

Astrophysics · Physics 2009-10-30 S. Matarrese , S. Mollerach , M. Bruni

Two effectively one-dimensional parallel coupled Bose-Einstein condensates in the presence of external potentials are studied. The system is modelled by linearly coupled Gross-Pitaevskii equations. In particular, grey-soliton-like solutions…

Pattern Formation and Solitons · Physics 2015-05-28 Muhammad I. Qadir , Hadi Susanto , Paul C. Matthews

We consider a quasi-one-dimensional two-component Bose-Einstein condensate subject to a coherent coupling between its components, such as realized in spin-orbit coupled condensates. We study how nonlinearity modifies the dynamics of the…

Quantum Gases · Physics 2016-04-20 T. Congy , A. Kamchatnov , N. Pavloff

In this work we derive a scenario {in which} the early universe consists of {radiation fluid} and Bose-Einstein condensate. The possibility of gravitational self-interaction due to an attractive Bose-Einstein condensate is analyzed. The…

General Relativity and Quantum Cosmology · Physics 2019-05-28 F. G. Alvarenga , L. G. Ferreira Filho , R. Fracalossi , R. C. Freitas , S. V. B. Gonçalves , G. A. Monerat , G. Oliveira-Neto , E. V. Corrêa Silva

The density density correlation function is computed for the Bogoliubov pseudoparticles created in a Bose-Einstein condensate undergoing a black hole flow. On the basis of the gravitational analogy, the method used relies only on quantum…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Paul R. Anderson , Roberto Balbinot , Alessandro Fabbri , Renaud Parentani

We consider a Bose-Einstein condensate, which is confined in a very tight toroidal/annular trap, in the presence of a potential, which breaks the axial symmetry of the Hamiltonian. We investigate the stationary states of the condensate,…

The close theoretical analogy between the physics of rapidly rotating atomic Bose condensates and the quantum Hall effect (i.e., a two dimensional electron gas in a strong magnetic field) was first pointed out ten years ago. As a…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Susanne Viefers

We show that a recent proposal for the quantization of gravity based on discrete space-time implies a modification of standard quantum mechanics that naturally leads to a loss of coherence in quantum states of the type discussed by Milburn.…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Rodolfo Gambini , Rafael Porto , Jorge Pullin

The Bogoliubov theory is extended to a Bose-Einstein condensation with internal degrees of freedom, realized recently in $^{23}$Na gases where several hyperfine states are simultaneously cooled optically. Starting with a Hamiltonian…

Condensed Matter · Physics 2009-10-31 Tetsuo Ohmi , Kazushige Machida

In this work, in the context of modified gravity, a curved spacetime analogous to the "canonical acoustic black hole" is constructed. The source is a self-interacting scalar field which is non-minimally coupled to gravity through the…

General Relativity and Quantum Cosmology · Physics 2021-06-09 Pedro Cañate , Joseph Sultana , Demosthenes Kazanas

Two effectively one-dimensional parallel coupled Bose-Einstein condensates in the presence of external potentials are studied. The system is modelled by linearly coupled Gross-Pitaevskii equations. In particular, the interactions of…

Mathematical Physics · Physics 2015-06-16 M. I. Qadir , H. Susanto , P. C. Matthews

We theoretically investigate superradiance effects in quantum field theories in curved space-times by proposing an analogue model based on Bose--Einstein condensates subject to a synthetic vector potential. The breaking of the…

Quantum Gases · Physics 2021-04-08 Luca Giacomelli , Iacopo Carusotto

We study the detailed out of equilibrium time evolution of a homogeneous Bose-Einstein condensate.We consider a nonrelativistic quantum theory for a self-interacting complex scalar field, immersed in a thermal bath, as an effective…

Soft Condensed Matter · Physics 2009-10-31 Daniel G. Barci , E. S. Fraga , Rudnei O. Ramos

We present theoretical analysis and numerical studies of the quantized vortices in a rotating Bose-Einstein condensate with spatiotemporally modulated interaction in harmonic and anharmonic potentials, respectively. The exact quantized…

Quantum Gases · Physics 2015-05-30 Deng-Shan Wang , Shu-Wei Song , Bo Xiong , W. M. Liu

We provide a detailed description of the nonequilibrium time evolution of an interacting homogeneous Bose-Einstein condensate. We use a nonperturbative in-medium quantum field theory approach as a microscopic model for the Bose gas. The…

Soft Condensed Matter · Physics 2007-05-23 D. G. Barci , E. S. Fraga , Rudnei O. Ramos

We extend the earlier model of condensate growth of Davis et al [Davis MJ, Gardiner CW and Ballagh RJ 2000, Phys. Rev. A 62, 063608] to include the effect of gravity in a magnetic trap. We carry out calculations to model the experiment…

Condensed Matter · Physics 2009-11-07 MJ Davis , CW Gardiner

The interplay between matter particles and gauge fields in physical spaces with nontrivial geometries can lead to novel topological quantum matter. However, detailed microscopic mechanisms are often obscure, and unconventional spaces are…

Models of evaporating black holes are constructed using the new solutions of Einstein's equations with perfect fluid in space-times with FLRW asymptotic behaviour derived recently [I. I. Cotaescu, Eur. Phys. J. C (2022) 82:86]. The dynamics…

General Relativity and Quantum Cosmology · Physics 2025-02-18 Ion I. Cotaescu

An alternative quantum field theory for gravity is proposed for low energies based on an attractive effect between contaminants in a Bose-Einstein Condensate rather than on particle exchange. In the ``contaminant in condensate effect,"…

High Energy Physics - Theory · Physics 2007-05-23 Alexander Oshmyansky

We consider the quantum dynamics of Bose-Einstein condensates at absolute zero, and demonstrate that an analogue gravity model going beyond the standard linearized analogue gravity paradigm \`a la Unruh must take into account the…

General Relativity and Quantum Cosmology · Physics 2024-12-25 Kunal Pal , Uwe R. Fischer
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