Related papers: Acoustic quasibound states and tachyonic instabili…
For ultra-light scalar particles like axions, dark matter can form a state of the Bose-Einstein condensate (BEC) with a coherent classical wave whose wavelength is of order galactic scales. In the context of an oscillating scalar field with…
The main aim of this study is to reveal curved space and particle physics effects on the formation of Bose-Einstein condensate (BEC) scalar fields in cosmology and around a black hole. Cosmological scalar fields for dark energy and dark…
We demonstrate parametric resonance in Bose-Einstein condensates (BECs) with attractive two-body interaction in a harmonic trap under parametric excitation by periodic modulation of the s-wave scattering length. We obtain nonlinear…
We have studied theoretically the Bose-Einstein condensation (BEC) of two-dimensional excitons in a ring with small random width variation. We derive a nonlinear Gross-Pitaevkii equation (GPE) for such a condensate. Our numerical solution…
We consider two-dimensional (2D) localized vortical modes in the three-wave system with the quadratic ($\chi ^{(2)}$) nonlinearity, alias nondegenerate second-harmonic-generating system, guided by the isotropic harmonic-oscillator (HO)…
Shaking optical lattices in a resonant manner offers an efficient and versatile method to devise artificial gauge fields and topological band structures for ultracold atomic gases. This was recently demonstrated through the experimental…
In this paper we study dark solitons in quasi-one-dimensional Bose-Einstein condensates (BECs) in presence of an anharmonic external potential. The theoretical model is based on the Mu\~noz-Mateo and Delgado (MMD) equation that describes…
Early during the era of cosmic inflation, rotational invariance may have been broken, only later emerging as a feature of low-energy physics. This motivates ongoing searches for residual signatures of anisotropic space-time, for example in…
We review the recent developments which had taken place in the domain of quasi one dimensional BECs from the viewpoint of integrability. To start with, we consider the dynamics of scalar BECs in a time independent harmonic trap and observe…
In this paper, the viscous cosmological dynamics are studied in the presence of dark matter Bose-Einstein Condensation (BEC) by curved-FRW background. For this purpose, we use the BEC regime rather than the normal dark matter (the cold dark…
We present a new model of BEC dynamics based on strong confinement near the ground state. The model predicts oscillations in a two-component condensate, based on interference of non-spreading wave packets moving within a pair of tilted…
Bose-Einstein condensates subject to short pulses (`kicks') from standing waves of light represent a nonlinear analogue of the well-known chaos paradigm, the quantum kicked rotor. Previous studies of the onset of dynamical instability (ie…
Correspondence between frequency and energy spectra and biorthogonality conditions for the excitations of Bose-Einstein condensates described by Gross-Pitaevskii model have been derived selfconsistently revealing several novel aspects…
We explore the time evolution of quasi-1D two component Bose-Einstein condensates (BEC's) following a quench from one component BEC's with a ${\rm U}(1)$ order parameter into two component condensates with a ${\rm U}(1)\shorttimes{\rm Z}_2$…
The dynamics of a quantum anharmonic oscillator whose position is monitored by a Bose-Einstein condensate (BEC) trapped in a symmetric double well potential is studied. The (non-exponential) decoherence induced on the oscillator by the…
We study the dynamical stability of Bose-Einstein condensates in an optical lattice with a time-periodic modulation potential and a constant acceleration force simultaneously. We derive the explicit expressions of quasienergies and obtain…
To show a mechanism leading to the breakdown of a particle picture for the multi-component Bose-Einstein condensates(BECs) with a harmonic trap in high dimensions, we investigate the corresponding 2-$d$ nonlinear Schr{\"o}dinger equation…
We report the Bose-Einstein condensate (BEC) in the Bloch bands with off-diagonal periodic potential (ODPP), which simultaneously plays the role of spin-orbit coupling (SOC) and Zeeman field. This model can be realized using two independent…
This paper suggests a method for an experiment to create dark soliton-like waves in a trapped atomic Bose-Einstein condensate (BEC). With the phase imprinting method, a soliton-like disturbance is produced along the x-axis. The method is…
We analyse systematically, from the viewpoint of the nonlinear physics of solitary waves, the effect of the spatial dimension (D = 1,2,3) on the structure and stability of the Bose-Einstein condensates (BECs) trapped in an external…