scholarly journals Analyzing the Effects of Topological Defect (TD) on the Energy Spectra and Thermal Properties of LiH, TiC and I2 Diatomic Molecules

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 1060
Author(s):  
Peter Nwabuzor ◽  
Collins Edet ◽  
Akpan Ndemikot ◽  
Uduakobong Okorie ◽  
Morris Ramantswana ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Cosmic String ◽  
Deformation Parameter ◽  
Topological Defect ◽  
Diatomic Molecules ◽  
Minkowski Spacetime ◽  
Energy Spectra ◽  
Generalized Morse Potential ◽  
The Universe ◽  
Astrophysical Situation

In this study, the impacts of TD on the energy spectra and thermal properties of LiH, TiC and I2 diatomic molecules is considered. The Schrodinger equation in cosmic string spacetime is solved with the generalized Morse potential using the well-known (NU) method. The energy spectra and eigenfunction are obtained respectively. The energy spectra is used to obtain the partition function which is then used to evaluate the thermal properties of the system is evaluated accordingly. We find that the energy spectra in the presence of the TD differ from their flat Minkowski spacetime analogue. The effects of the deformation parameter and TD on the thermal properties of the system is also analysed in detail. We observe that the specific heat capacity of the system tends to exhibit quasi-saturation as the deformation parameter and topological defect approaches unity. The results of our study can be applied in the astrophysical situation where these modifications exist in the understanding of spectroscopical data and it may be used as a probe of the presence of a cosmic string or a global monopole in the Universe.

SOME REMARKS ON TOPOLOGICAL DEFECTS AND THEIR GRAVITATIONAL CONSEQUENCES

2002 ◽  
Vol 17 (29) ◽  
pp. 4365-4374 ◽  
Author(s):  
VALDIR B. BEZERRA ◽  
GEUSA DE A. MARQUES ◽  
NAIL R. KHUSNUTDINOV
Keyword(s):  
Hydrogen Atom ◽  
Cosmic String ◽  
Topological Defect ◽  
Solid Angle ◽  
Topological Defects ◽  
Scalar Particle ◽  
Global Monopole ◽  
Charged Scalar ◽  
Charged Scalar Particle ◽  
The Universe

We calculate the energy radiated by a uniformly moving charged scalar particle in the spacetime of a point-like global monopole, for small solid angle deficit. We show that this energy is proportional to the cube of the velocity of the particle and to the cube of the Lorenz factor, in the non-relativistic and ultra-relativistic cases, respectively. We also determine the energy shifts of a hydrogen atom placed in the background spacetime of a cosmic string and we discuss the possibility that these shifts could provide a means of probing for the presence of this topological defect in the Universe.

scholarly journals Graphene, Graphene-Derivatives and Composites: Fundamentals, Synthesis Approaches to Applications

2021 ◽  
Vol 5 (7) ◽  
pp. 181
Author(s):  
Dibyani Sahu ◽  
Harekrushna Sutar ◽  
Pragyan Senapati ◽  
Rabiranjan Murmu ◽  
Debashis Roy
Keyword(s):  
Thermal Properties ◽  
Lattice Structure ◽  
Honeycomb Structure ◽  
The Novel ◽  
Graphene Derivatives ◽  
Novel Applications ◽  
The Universe

Graphene has accomplished huge notoriety and interest from the universe of science considering its exceptional mechanical physical and thermal properties. Graphene is an allotrope of carbon having one atom thick size and planar sheets thickly stuffed in a lattice structure resembling a honeycomb structure. Numerous methods to prepare graphene have been created throughout a limited span of time. Due to its fascinating properties, it has found some extensive applications to a wide variety of fields. So, we believe there is a necessity to produce a document of the outstanding methods and some of the novel applications of graphene. This article centres around the strategies to orchestrate graphene and its applications in an attempt to sum up the advancements that has taken place in the research of graphene.

Feshbach–Villars equation in a κ-Minkowski spacetime

2020 ◽  
Vol 35 (37) ◽  
pp. 2050307
Author(s):  
B. Hamil ◽  
M. Merad
Keyword(s):  
Experimental Data ◽  
Perturbation Theory ◽  
Deformation Parameter ◽  
Order Approximation ◽  
Minkowski Spacetime ◽  
Magnetic Interaction ◽  
Relativistic Limit ◽  
First Order ◽  
Klein Gordon ◽  
First Order Approximation

In this paper, by using the Dirac derivatives the Klein–Gordon (K-G) equation is determined in a [Formula: see text]-Minkowski spacetime. The dispersion relation and the first-order approximation case are deduced. The Feshbach–Villars (FV) equation is derived by applying the new linearization process to the time. We then study the effect of magnetic interaction on energies spectrum in a [Formula: see text]-Minkowski spacetime as an application, as a result we found that the energies spectrum are not symmetrical. We also study the case of hydrogen atom in non-relativistic limit by using perturbation theory. The upper bound of the [Formula: see text]-deformation parameter is evaluate, on the basis of the experimental data for [Formula: see text] transition frequency.

scholarly journals Accelerating Universe with Viscous Cosmic String in Quadratic Form of Teleparallel Gravity

2019 ◽  
Vol 11 (3) ◽  
pp. 249-262
Author(s):  
S. R. Bhoyar ◽  
V. R. Chirde ◽  
S. H. Shekh
Keyword(s):  
Cosmic String ◽  
Teleparallel Gravity ◽  
Negative Slope ◽  
Accelerating Universe ◽  
Field Equations ◽  
Physical Behavior ◽  
Torsion Scalar ◽  
Bulk Viscous ◽  
The Universe ◽  
Physical Quantities

In this paper, we have investigated Kantowaski-Sachs cosmological model with bulk viscous and cosmic string in the framework of Teleparallel Gravity so called f(T) gravity, where T denotes the torsion scalar. The behavior of accelerating universe is discussed towards the particular choice of f(T) = Α(T) + β(T)m. The exact solutions of the field equations are obtained by applying variable deceleration parameter which is linear in time with a negative slope. The physical behavior of these models has been discussed using some physical quantities. Also, the function of the torsion scalar for the universe is evaluated.

scholarly journals Is Cosmic String Domination of the Universe Avoidable?

1988 ◽  
Vol 130 ◽  
pp. 289-291
Author(s):  
François R. Bouchet ◽  
David P. Bennett
Keyword(s):  
Numerical Simulations ◽  
Galaxy Formation ◽  
Cosmic String ◽  
Numerical Technique ◽  
Scaling Hypothesis ◽  
Scaling Solution ◽  
The Universe

We address, by means of Numerical Simulations, one of the main issues of the Cosmic String Galaxy Formation Scenario, namely the existence of a scaling solution, which is crucial to the very existence of the scenario. After a brief discussion of our numerical technique, we present our results which, though still preliminary, offer the best support to date of this scaling hypothesis.

scholarly journals Entanglement dynamics for static two-level atoms in cosmic string spacetime

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
Pingyang He ◽  
Hongwei Yu ◽  
Jiawei Hu
Keyword(s):  
Cosmic String ◽  
Minkowski Spacetime ◽  
Scalar Fields ◽  
Entangled State ◽  
Entanglement Dynamics ◽  
Entanglement Generation ◽  
Maximally Entangled State ◽  
Interatomic Separation ◽  
Antisymmetric State ◽  
String Distance

Abstract We study the entanglement dynamics of two static atoms coupled with a bath of fluctuating scalar fields in vacuum in the cosmic string spacetime. Three different alignments of atoms, i.e. parallel, vertical, and symmetric alignments with respect to the cosmic string are considered. We focus on how entanglement degradation and generation are influenced by the cosmic string, and find that they are crucially dependent on the atom-string distance r, the interatomic separation L, and the parameter $$\nu $$ν that characterizes the nontrivial topology of the cosmic string. For two atoms initially in a maximally entangled state, the destroyed entanglement can be revived when the atoms are aligned vertically to the string, which cannot happen in the Minkowski spacetime. When the symmetrically aligned two-atom system is initially in the antisymmetric state, the lifetime of entanglement can be significantly enhanced as $$\nu $$ν increases. For two atoms which are initially in the excited state, when the interatomic separation is large compared to the transition wavelength, entanglement generation cannot happen in the Minkowski spacetime, while it can be achieved in the cosmic string spacetime when the position of the two atoms is appropriate with respect to the cosmic string and $$\nu $$ν is large enough.

Diatomic molecules energy spectra for the generalized Mobius square potential model

2020 ◽  
Vol 34 (21) ◽  
pp. 2050209
Author(s):  
U. S. Okorie ◽  
A. N. Ikot ◽  
M. U. Ibezim-Ezeani ◽  
Hewa Y. Abdullah
Keyword(s):  
Dissociation Energy ◽  
Approximation Scheme ◽  
Potential Model ◽  
Vibrational Energy ◽  
Diatomic Molecules ◽  
Energy Spectra ◽  
Equilibrium Bond Length ◽  
Quantum Numbers ◽  
Vibrational Energies ◽  
Potential Parameters

The modified version of the generalized Mobius square (GMS) potential has been obtained by employing the dissociation energy and equilibrium bond length as explicit parameters. The potential parameters have been defined in terms of the molecular parameters. The modified GMS potential has also been used to model internuclear interaction potential curves for different states of diatomic molecules. Also, we have obtained the rotational–vibrational energy spectra of the new GMS potential model, both analytically and numerically for the different diatomic molecules. This was done by employing a Pekeris-type approximation scheme and an appropriate coordinate transformation to solve the Schrodinger equation. Our results have been compared with the experimental Rydberg–Klein–Rees (RKR) data and its corresponding average absolute deviations in terms of the dissociation energy computed. The effects of the vibrational and rotational quantum numbers on the rotational–vibrational energies for the different states of the various diatomic molecules have also been discussed. This paper has shown to be highly relevant to the studies of thermodynamic and thermochemical functions of diatomic molecules.

scholarly journals THE CIRCULAR LOOP EQUATION OF A COSMIC STRING WITH TIME-VARYING TENSION

2008 ◽  
Vol 23 (35) ◽  
pp. 3023-3030 ◽  
Author(s):  
HONGBO CHENG ◽  
YUNQI LIU
Keyword(s):  
Black Hole ◽  
Cosmic String ◽  
Cosmic Time ◽  
Minkowski Spacetime ◽  
Critical Value ◽  
Time Dependent ◽  
Time Varying ◽  
Circular Loop ◽  
Loop Equation

The equation of circular loops of cosmic string with time-dependent tension is studied in the Minkowski spacetime and Robertson–Walker universe. We found that, in the case where the tension depends on some power of the cosmic time, cosmic string loops with time-varying tension should not collapse to form a black hole if the power is lower than a critical value.

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