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Faizuddin Ahmed

Publications and source records attributed to Faizuddin Ahmed.

At least 163 records · Page 9Linked to original sources
arXiv2020

Quantum influence of topological defects on a relativistic scalar particle with Cornell-type potential in cosmic string space-time with a spacelike dislocation

We study the relativistic quantum of scalar particles in the cosmic string space-time with a screw dislocation (torsion) subject to a uniform magnetic field including the magnetic quantum flux in the presence of potential. We solve the Klein-Gordon equation with a Cornell-type scalar potential in the considered framework and obtain the energy eigenvalues and eigenfunctions and analyze a relativistic analogue of the Aharonov-Bohm effect for bound states

physics.gen-ph↗
arXiv2020

Effects of Kaluza-Klein theory and potential on a generalized Klein-Gordon oscillator in the cosmic string space-time

In this paper, we solve a generalized Klein-Gordon oscillator in the cosmic string space-time with a scalar potential of Cornell-type within the Kaluza-Klein theory and obtain the relativistic energy eigenvalues and eigenfunctions. We extend this analysis by replacing the Cornell-type with Coulomb-type potential in the magnetic cosmic string space-time and analyze a relativistic analogue of the Aharonov-Bohm effect for bound states.

physics.gen-ph↗
arXiv2020

Investigation of spin-$0$ massive charged particle subject to a homogeneous magnetic field with potentials in a topologically trivial flat class of Gödel-type space-time

In this paper, we investigate relativistic quantum dynamics of spin- $0$ massive charged particle subject to a homogeneous magnetic field in the Gödel-type space-time with potentials. We solve the Klein-Gordon equation subject to a homogeneous magnetic field in a topologically trivial flat class of Gödel-type space-time in the presence of a Cornell-type scalar and Coulomb-type vector potentials and analyze the effects on the energy eigenvalues and eigenfunctions.

gr-qc↗
arXiv2020

Klein-Gordon oscillator in the presence of external fields in a cosmic space-time with a spacelike dislocation and Aharonov-Bohm effect

In this paper, we study interactions of a scalar particle with electromagnetic potential in the background space-time generated by a cosmic string with a spacelike dislocation. We solve the Klein-Gordon oscillator in the presence of external fields including an internal magnetic flux field and analyze the analogue effect to the Aharonov-Bohm effect for bound states. We extend this analysis subject to a Cornell-type scalar potential and observe the effects on the relativistic energy eigenvalue and eigenfunction.

hep-th↗
arXiv2020

The generalized Klein-Gordon oscillator in the background of cosmic string space-time with a linear potential in the Kaluza-Klein theory

In this work, we study the generalized Klein-Gordon oscillator with interactions on a curved background within the Kaluza-Klein theory. We solve the generalized Klein-Gordon oscillator in the cosmic string space-time with a linear scalar potential and obtain the energy eigenvalue and corresponding eigenfunction. We show that the energy spectrum depends on the global parameters characterizing the space-time and the confining potential parameter. We also solve the generalized Klein-Gordon oscillator in a magnetic cosmic string background in the Kaluza-Klein theory with a linear scalar potential and analyze the analogue effect to the Aharonov-Bohm effect for bound states.

gr-qc↗
arXiv2020

Axial symmetry Type N space-time with a naked curvature singularity and Closed Time-like Curves

A family of type N exact solution of the Einstein's field equations, regular everywhere except on the symmetry axis where it possesses a naked curvature singularity, is present. The stress-energy tensor is of the anisotropic fluid coupled with pure radiation field satisfy the different energy conditions and the physical parameters diverge $r \rightarrow 0$. The space-time admitting a non-expanding, non-twisting, and shear-free geodesic null congruence and belongs to a special class of type N Kundt metrics. The space-time is geodesically complete along the radiation direction in the constant $z$-planes and exhibits geometrically different properties from the known pp-waves. The present family of solution admits closed time-like curves (CTC) which appear after a certain instant of time and the space-time is a four-dimensional generalization of the Misner space metric in curved space-time.

gr-qc↗
arXiv2020

Comment on "Ground state of a bosonic massive charged particle in the presence of external fields in a Gödel-type space-time [Eur. Phys. J. Plus (2018) 133 : 530]"

We point out incorrect equations derived in a paper published in this journal Ref. [1] (E. O. Silva, Eur. Phys. J. Plus (2018) 133 : 530) for the Klein-Gordon equation with the Aharonov-Bohm and Coulomb potentials in a Gödel-type space-time. We derive the final form of the radial wave equation of the Klein-Gordon equation in the Som-Raychaudhuri space-time with these potentials and show that the derive equation here jeopardize the equations obtained in Ref. [1] and therefore, the energy eigenvalues presented there is incorrect.

gr-qc↗
arXiv2019

Relativistic quantum dynamics of spin-0 massive charged particle in the presence of external fields in 4D curved space-time with a cosmic string

In this work, we investigate the relativistic quantum dynamics of spin-0 massive charged particles in a 4D curved space-time, the generalization of a cosmic string space-time. We investigate the Klein-Gordon equation in the presence of external fields in the considered framework. We also investigate a quantum particle described by the Klein-Gordon oscillator in the curved background space-time in the presence of external fields. We see that the energy eigenvalues get modifies in comparison to the results obtained in a cosmic string space-time.

hep-th↗
arXiv2019

The Dirac Equation in (1+2)-dimensional Gürses space-time backgrounds

In this article, we investigate the relativistic quantum dynamics of spin-$\frac{1}{2}$ particles in (1+2)-dimensional Gürses space-time backgrounds, and analyze the effects on the eigenvalues. We solve the Dirac equation using the Nikiforov-Uvarov method in the considered framework, and evaluate the energy eigenvalues and corresponding wave function.

gr-qc↗
arXiv2019

Cylindrical symmetric, non-rotating and non-static or static black hole solutions and the naked singularities

In this work, a four-dimensional cylindrical symmetric and non-static or static space-times in the backgrounds of anti-de Sitter (AdS) space with perfect stiff fluid, anisotropic fluid and electromagnetic field as the stress-energy tensor, is presented. For suitable parameter conditions in the metric function, the solution represents non-static or static non-rotating black hole solution. In addition, we show for various parameter conditions, the solution represents static and/or non-static models with a naked singularity without an event horizon.

physics.gen-ph↗
arXiv2018

Black holes/naked singularities in four-dimensional non-static space-time and the energy-momentum distributions

In this article, we discuss four dimensional non-static space-times in the background of de-Sitter and anti-de Sitter spaces with the matter-energy sources a stiff fluid, anisotropic fluid, and an electromagnetic field. Under various parameter conditions the solutions may represent models of naked singularity and/or black holes. Finally, the energy-momentum distributions using the complexes of Landau-Lifshitz, Einstein, Papapetrou, and Møller prescriptions, were evaluated.

gr-qc↗
arXiv2018

A type N radiation field solution with $Λ<0$ in a curved space-time and closed time-like curves

An anti-de Sitter background four-dimensional type N solution of the Einstein's field equations, is presented. The matter-energy content pure radiation field satisfies the null energy condition (NEC), and the metric is free-from curvature divergence. In addition, the metric admits a non-expanding, non-twisting and shear-free geodesic null congruence which is not covariantly constant. The space-time admits closed time-like curves which appear after a certain instant of time in a causally well-behaved manner. Finally, the physical interpretation of the solution, based on the study of the equation of the geodesics deviation, is analyzed.

gr-qc↗
arXiv2018

A cylindrically symmetric, static anisotropic fluid spacetime and the naked singularity

In this article, a cylindrical symmetry and static solution of the Einstein's field equations, was presented. The space-time is conformally flat, regular everywhere except on the symmetry axis where it possesses a naked curvature singularity. The matter-energy source anisotropic fluids violates the weak energy condition (WEC), diverge on the symmetry axis. We discuss geodesics motion of free test-particles near to the singularity, and geodesic expansion in the metric to understand the nature of singularity which is naked or covered, and finally the C-energy of the space-time.

physics.gen-ph↗
arXiv2017

A Type D Non-Vacuum Spacetime with Causality Violating Curves, and its Physical Interpretation

We present a topologically trivial, non-vacuum solution of the Einstein's field equations in four-dimensions, which is regular everywhere. The metric admits circular closed timelike curves, which appear beyond the null curve, and these timelike curves are linearly stable under linear perturbations. Additionally, the spacetime admits null geodesics curve which are not closed, and the metric is of type D in the Petrov classification scheme. The stress-energy tensor anisotropic fluid satisfy the different energy conditions and a generalization of Equation-of-State parameter of perfect fluid $p=ω\,ρ$. The metric admits a twisting, shearfree, non-exapnding timelike geodesic congruence. Finally, the physical interpretation of this solution, based on the study of the equation of the geodesics deviation, will be presented.

gr-qc↗
arXiv2017

Axially Symmetric Null dust Spacetime, Naked Singularity and Cosmic Time Machine

In this article, we present a gravitational collapse null dust solution of the Einstein field equations. The spacetime is regular everywhere except on the symmetry axis where it possesses a naked curvature singularity, and admits one parameter isometry group, a generator of axial symmetry along the cylinder which has closed orbits. The space- time admits closed timelike curves (CTCs) which develop at some particular moment in a causally well-behaved manner and may represent a Cosmic Time Machine. The radial geodesics near to the singularity, and the gravitational Lensing (GL) will be discussed. The physical interpretation of this solution, based on the study of the equation of the geodesic deviation, will be presented. It was demonstrated that, this solution depends on the local gravitational field consisting of two components with amplitude $Ψ_2$, $Ψ_4$.

gr-qc↗