Physics

We study the relativistic quantum dynamics of spin- 0 massive charged particle in a Gödel-type space-time with electromagnetic interactions. We solve the Klein-Gordon equation subject to a uniform magnetic field in the Som-Raychaudhuri space-time with a cosmic string. In addition, we include a magnetic quantum flux into the relativistic quantum system obtain the energy eigenvalues and analyze an analogue of the Aharonov-Bohm (AB) effect.

We present a brief introduction to the topological phases of matter. This is a brief review article written for the Boletin de la Sociedad Mexicana de Fisica

Employing a new approach toward thermodynamic phase space, we investigate the phase transition, critical behavior and microscopic structure of higher dimensional black holes in an Anti-de Sitter (AdS) background and in the presence of Power-Maxwell field. In contrast to the usual extended P−V phase space where the cosmological constant (pressure) is treated as a thermodynamic variable, we fix the cosmological constant and treat the charge of the black hole (or more precisely Q s ) as a thermodynamic variable. Based on this new standpoint, we develop the resemblance between higher dimensional nonlinear black hole and Van der Waals liquid-gas system. We write down the equation of state as , where ψ is the conjugate of Q s , and construct a Smarr relation based on this new phase space as M=M(S,P, Q s ) , while and p is the power parameter of the Power-Maxwell Lagrangian. We obtain the Gibbs free energy of the system and find a swallowtail behaviour in Gibbs diagrams, which is a characteristic of first-order phase transition and express the analogy between our system and van der Waals fluid-gas system. Moreover, we calculate the critical exponents and show that they are independent of the model parameters and are the same as those of Van der Waals system which is predicted by the mean field theory. Finally , we successfully explain the microscopic behavior of the black hole by using thermodynamic geometry. We observe a gap in the scalar curvature R occurs between small and large black hole. The maximum amount of the gap increases as the number of dimensions increases. We finally find that character of the interaction among the internal constituents of the black hole thermodynamic system is intrinsically a strong repulsive interaction.

A goal of physics is to understand the greatest possible breadth of natural phenomena in terms of the most economical set of basic concepts. However, as the understanding of physics has developed historically, its pedagogy and language have not kept pace. This gap handicaps the student and the practitioner, making it harder to learn and apply ideas that are `well understood', and doubtless making it more difficult to see past those ideas to new discoveries. Energy, momentum, and action are archaic concepts representing an unnecessary level of abstraction. Viewed from a modern perspective, these quantities correspond to wave parameters, namely temporal frequency, spatial frequency, and phase, respectively. The main results of classical mechanics can be concisely reproduced by considering waves in the spacetime defined by special relativity. This approach unifies kinematics and dynamics, and introduces inertial mass not via a definition, but rather as the real-space effect of a reciprocal-space invariant.

We suggest that the unusual events observed by the ANITA experiment originate from axion particles traversing the Earth. Under the influence of the geomagnetic field, the axion may oscillate into a photon and vice-versa. To amplify the axion transition into photon, we consider that the phenomenon takes place at resonance, where the effective photon mass is equal to the axion mass. This requirement fixes the axion mass at 200 eV. An axion at this mass scale reproduces the cold dark matter scenario. If our interpretation prevails, with the help of axions we can establish an axion tomography of the Earth.

This is an article which intends to shake down the traditional belief that the celebrated Adler-Bell-Jackiw anomaly stems from the chiral rotation non-invariance of the fermionic measure. The fermionic functional integration measure in quantum field theory should be defined so as to reproduce the standard Feynman diagrammatic expansion. This implies that a plain definition of the fermionic measure automatically serves such a purpose. A dilemma then arises: how could one identify the ABJ anomaly as a nontrivial Jacobian factor for a chiral transformation ? The true answer is indeed surprising and unexpected, that is, the Jacobian factor is actually a random and indeterminate object, hence it carries no physical information. A true explanation for the ABJ anomaly is suggested.

In this paper, we have presented an FLRW universe containing two-fluids (baryonic and dark energy) with a deceleration parameter (DP) having a transition from past decelerating to the present accelerating universe. In this model, dark energy (DE) interacts with dust to produce a new law for the density. As per our model, our universe is at present in a phantom phase after passing through a quintessence phase in the past. The physical importance of the two-fluid scenario is described in various aspects. The model is shown to satisfy current observational constraints such as recent Planck results. Various cosmological parameters relating to the history of the universe have been investigated.

We review consequences for the radiation and dark sectors of the cosmological model arising from the postulate that the Cosmic Microwave Background (CMB) is governed by an SU(2) rather than a U(1) gauge principle. We also speculate on the possibility of actively assisted structure formation due to the de-percolation of lump-like configurations of condensed ultralight axions with a Peccei-Quinn scale comparable to the Planck mass. The chiral-anomaly induced potential of the axion condensate receives contributions from SU(2)/SU(3) Yang-Mills factors of hierarchically separated scales which act in a screened (reduced) way in confining phases.

The present contribution aims at obtaining the energy/dark energy fraction of the universe by starting from the Sitter vacuum only and without involving any additional source of energy. To do so, we consider two different standard solutions of the Einstein vacuum equations with positive cosmological constant. In accordance with [9][10], we initially derive an uncertainty principle for the associated spherical and hyperbolical time-slices to highlight the connection between the classical notion of spatial curvature and the quantum mechanical uncertainty of position and momentum in de Sitter space (Theorem). Based on the positive and negative curvatures of these foliations, an alternative notion of (time-dependent) energy and dark energy of the vacuum is established. This opens the possibility of a formal derivation of Einstein's gravitational constant κ by matching the dark energy contribution at the Planck scale at one Planck time after the initial singularity. Moreover, for the fraction of 70\% dark energy, the age of the universe is estimated to be about 13.7 billion years. Finally, we verify that the metric corresponding to a suitable junction of the hyperbolic and the spherical foliation is a solution of Einstein's field equations. This suggests a cosmology given by a de Sitter space embedded into an asymptotic Schwarzschild-Anti-de Sitter background.

The resolution of Mansuripur's paradox appears in numerous papers in the physics literature, preserves the Lorentz force but depends on the concept of hidden momentum. Here I propose a different resolution based on the overlooked fact that the charge-magnetic dipole system contains linear and angular electromagnetic field momentum. The time rate of change of the field angular momentum in the frame through which the system is moving cancels that due to the charge-electric dipole interaction. From this point of view hidden momentum is not needed in the resolution of the paradox.