arXiv subjects

E. Castellanos

Publications and source records attributed to E. Castellanos.

8 recordsLinked to original sources

arXiv2014

Planck-Scale Traces from the Interference Pattern of two Bose-Einstein Condensates

We analyze the possible effects arising from Planck scale regime upon the interference pattern of two non-interacting Bose-Einstein condensates. We start with the analysis of the free expansion of a condensate, taken into account the effects produced by a deformed dispersion relation, suggested in several quantum-gravity models. The analysis of the condensate free expansion, in particular, the modified free velocity expansion, suggests in a natural way, a modified uncertainty principle that could leads to new phenomenological implications related to the quantum structure of space time. Finally, we analyze the corresponding separation between the interference fringes after the two condensates overlap, in order to explore the sensitivity of the system to possible signals caused by the Planck scale regime.

gr-qc↗

arXiv2014

Planck Scale Induced Speed of Sound in a Trapped Bose-Einstein Condensate

In the present work, we analyze the corrections caused by an anomalous dispersion relation, suggested in several quantum gravity models, upon the speed of sound in a weakly interacting Bose--Einstein Condensate, trapped in a potential of the form $V(r)\sim r^{2}$. We show that the corresponding ground state energy and consequently, the associated speed of sound, present corrections respect to the usual case, which may be used to explore the sensitivity to Planck--scale effects on these relevant properties associated with the condensate. Indeed, we stress that this type of macroscopic bodies may be more sensitive, under certain conditions, to Planck--scale manifestations than its constituents. In addition, we prove that the inclusion of a trapping potential, together with many--body contributions, improves the sensitivity to Planck--scale signals, compared to the homogeneous system.

gr-qc↗

arXiv2014

Weakly interacting Bose-Einstein condensates in temperature-dependent generic traps

The shift in condensation temperature caused by interactions is studied up to second order in the s-wave scattering length in a Bose-Einstein condensate trapped in a temperature-dependent three-dimensional generic potential. With no assumptions other than the mean-field approach and semiclassical approximations it is shown that the inclusion of a temperature-dependent trap improves the empirical values of the numerical parameters compared to those obtained in previous reports on the temperature shift.

cond-mat.quant-gas↗

arXiv2014

Modified Bosonic Gas Trapped in a Generic 3-dim Power Law Potential

We analyze the consequences caused by an anomalous single-particle dispersion relation suggested in several quantum-gravity models, upon the thermodynamics of a Bose-Einstein condensate trapped in a generic 3-dimensional power-law potential. We prove that the condensation temperature is shifted as a consequence of such deformation and show that this fact could be used to provide bounds on the deformation parameters. Additionally, we show that the shift in the condensation temperature, described as a non-trivial function of the number of particles and the trap parameters, could be used as a criterion to analyze the effects caused by a deformed dispersion relation in weakly interacting systems and also in finite size systems.

cond-mat.stat-mech↗

arXiv2013

Planck Scale Physics and Bogoliubov Spaces in a Bose-Einstein Condensate

We analyze the consequences caused by a deformed dispersion relation, suggested in several quantum gravity models, upon a bosonic gas. Concerning the ground state of the Bogoliubov space of this system, we deduce the corrections in the pressure, the speed of sound, and the corresponding healing length. Indeed, we prove that the corrections in the relevant thermodynamic properties associated with the ground state, defines a non trivial function of the density of particles and the deformation parameters, allowing us to constrain, in principle, the form of the modified energy-momentum dispersion relation.

gr-qc↗

arXiv2013

Polymer Bose--Einstein Condensates

In this work we analyze a non--interacting one dimensional polymer Bose--Einstein condensate in an harmonic trap within the semiclassical approximation. We use an effective Hamiltonian coming from the polymer quantization that arises in loop quantum gravity. We calculate the number of particles in order to obtain the critical temperature. The Bose--Einstein functions are replaced by series, whose high order terms are related to powers of the polymer length. It is shown that the condensation temperature presents a shift respect to the standard case, for small values of the polymer scale. In typical experimental conditions, it is possible to establish a bound for $λ^{2}$ up to $ \lesssim 10 ^{-16}$m$^2$. To improve this bound we should decrease the frequency of the trap and also decrease the number of particles.

gr-qc↗

arXiv2012

Ideal-Modified Bosonic Gas Trapped in an Arbitrary Three Dimensional Power-Law Potential

We analyze the effects caused by an anomalous single-particle dispersion relation suggested in several quantum-gravity models, upon the thermodynamics of a Bose-Einstein condensate trapped in a generic 3-dimensional power-law potential. We prove that the shift in the condensation temperature, caused by a deformed dispersion relation, described as a non-trivial function of the number of particles and the shape associated to the corresponding trap, could provide bounds for the parameters associated to such deformation. Additionally, we calculate the fluctuations in the number of particles as a criterium of thermodynamic stability for these systems. We show that the apparent instability caused by the anomalous fluctuations in the thermodynamic limit can be suppressed considering the lowest energy associated to the system in question.

math-ph↗

arXiv2012

Ultra--cold gases and the detection of the Earth's rotation: Bogoliubov space and gravitomagnetism

The present work analyzes the consequences of the gravitomagnetic effect of the Earth upon a bosonic gas in which the corresponding atoms have a non--vanishing orbital angular momentum. Concerning the ground state of the Bogoliubov space of this system we deduce the consequences, on the pressure and on the speed of sound, of the gravitomagnetic effect. We prove that the effect on a single atom is very small, but we also show that for some thermodynamical properties the consequences scale as a non--trivial function of the number of particles.

gr-qc↗