arXiv subjects

Emre Dil

Publications and source records attributed to Emre Dil.

10 recordsLinked to original sources

arXiv2021

Compact Q-Stars with q,p-Deformed Fermions

The Q-Star structures, also called as gray holes with a radius of two times greater than the corresponding Schwarzschild radius of same mass and from the compact neutron star family with a very high density, have been obtained by using a generalization of $q$-deformed fermions with two parameters $q$ and $p$ as the constituents of the star. Because the interaction between particles are controlled by deformation parameters in $q,p$-fermions instead of a complicated interaction Lagrangian, we consider the deformation parameters giving the maximum Q-Star pressure between the interacting particles of stars. The cold and hot Q-Stars in temperatures of $T=0$, $T=40\ \mathrm{MeV}$ and $T=60\ \mathrm{MeV}$ have been investigated from the numerical solutions of TOV equations and it is obtained that the Q-Stars can reach up to $13$ solar mass and $75$ Km radius. Moreover, it is found that the total mass and radius of the star increase when the star gets cool down, and a much denser state is reached.

physics.gen-ph↗

arXiv2020

Spin-Torsion effect on collapsing of first generation stars into neutron stars rather than black holes in Einstein-Cartan-Sciama-Kibble theory

In this project, we try to find the correlation between the non-local pressure inside the massive neutron stars resisting the gravitational collapse of the core and ECSK dark energy led by the effect of spin-torsion coupling between quark fields and the space-time at very high densities much larger than the nuclear density. The injection of dark energy into the core of massive neutron stars (MANs) and extra resistant nature of this dark energy to the collapse of MANs by the anti-gravity give the possibility of existence of neutron stars in the unobserved mass range of $[2.16M_{\odot},5M_{\odot}]$. Obtaining the ECSK TOV equation gives the local pressure of the ambient medium of MANs. Moreover, the negative pressure from the ECSK dark energy is obtained from the Lagrangian again, from which we are able to investigate the hydro-static equilibrium of the core and ambient medium of the MANs. If the equilibrium state is satisfied for the unobserved mass gap for the MANs in ECSK theory framework this will imply our model predicts this vast mass range of unobserved spectrum of the MANs in astrophysical studies.

physics.gen-ph↗

arXiv2020

Interaction of Fermionic Matter and ECSK Black Hole with Torsion

The interactions between the spin of fermionic matter and torsion in the Einstein-Cartan-Sciama-Kibble (ECSK) theory of gravity provides a repulsive gravitational potential at the very dense states of fermionic matter, which prevents the formation of black hole singularities inside the deeper horizon. While the fermionic matter in the black hole is attracted by the black hole at the beginning, after a critical point it is repelled to bounce at a critical high density and then expand into other side of the horizon as a newly created space, which may be considered as a nonsingular, closed universe. We constructed the action of these fermions in a black hole with torsion in the framework of ECSK theory of gravity from which the free Dirac action is inferred to obtain the interaction potential. The creation of a bouncing universe with the extremely repulsive potential may be related to the running vacuum and the modified Friedmann equations yield the consistent cosmological parameters with present FRW universe. Finally, this scenario naturally solves the flatness and horizon problems of cosmology without introducing finely tuned scalar fields, or more complicated functions of the Ricci Scalar R in the gravitational action.

physics.gen-ph↗

arXiv2018

Adiabatic expansion of polytropic universe with varying cosmological constant: Models tested with observational data

We use two large collections of observational data of supernovae type Ia (SNe Ia) to investigate the polytropic Universe including the situation with a varying cosmological constant; details of our new derivations are presented. We examine the fitness of our new models of a polytropic Universe with two sets of SNe Ia data to test if these are better descriptions than the current standard model of cosmology. Beginning with the established relationships for polytropic matter we derive new equations describing the influence of polytropic matter on the expanding Universe including the situation with a varying cosmological constant. When the models derived here are tested with large sets of supernovae type I a data we find a significant influence of polytropic matter on the state of our expanding Universe. We find that one of our models with a varying {\Lambda} describes the SNe Ia data significantly better than the, {\Lambda}CDM, standard model.

gr-qc↗

arXiv2017

On the entropic nature of unified interactions

In this paper, we generalize Verlinde's entropic gravity proposal on the other fundamental interactions of nature. We begin by introducing the entropic origin of the Coulomb's electrostatic force, and then the magnetic force, by assuming the holographic principle holds when a charged particle approaches a screen enclosing the emerged part of the spacetime due to a source. We assume that the entropy of the screen changes when the charge approaches as in the Verlinde's approach. Thereafter, we obtain the entropic Maxwell equations in both classical and covariant form by means of the holographic principle hold for the source. Considering the gauge covariant structure of the fundamental forces, we implicitly generalize the entropic origin of the electromagnetic force into the strong and weak nuclear forces. The possibility of the entropic origin of the all fundamental forces of nature is assumed to make a meaningful contribution to the unification scheme of the fundamental forces.

physics.gen-ph↗

arXiv2016

Interacting dark matter and q-deformed dark energy non-minimally coupled to gravity

In this paper, we propose a new approach to study the dark sector of the universe by considering the dark energy as emerging a q-deformed bosonic scalar field which is not only interacting with the dark matter, but also non-minimally coupled to gravity, in the framework of standard Einsteinian gravity. In order to analyze the dynamic of the system, we first give the quantum field theoretical description of the q-deformed scalar field dark energy, then construct the action and the dynamical structure of these interacting and non-minimally coupled dark sector. As a second issue, we perform the phase space analysis of the model to check the reliability of our proposal by searching the stable attractor solutions implying the late-time accelerating expansion phase of the universe.

gr-qc↗

arXiv2016

Dynamics of Mixed Dark Energy Domination in Teleparallel Gravity and Phase-Space Analysis

We consider a novel dark energy model to investigate whether it will provide an expanding universe phase. Here we propose a mixed dark energy domination which is constituted by tachyon, quintessence, and phantom scalar fields nonminimally coupled to gravity, in the absence of background dark matter and baryonic matter, in the framework of teleparallel gravity. We perform the phase-space analysis of the model by numerical methods and find the late-time accelerated attractor solutions implying the acceleration phase of universe.

physics.gen-ph↗

arXiv2016

Spinor quintom cosmology with intrinsic spin

We consider a spinor quintom dark energy model with intrinsic spin, in the framework of Eintein- Cartan-Sciama-Kibble theory. After constructing the mathematical formalism of the model, we obtain the spin contributed total energy-momentum tensor giving the energy density and the pressure of the quintom model, and then we find the equation of state parameter in terms of the spinor potential. Choosing suitable potentials leads to the quintom scenario crossing between quintessence and phantom epochs, or vice versa. Analyzed three quintom scenarios provides stable expansion phases avoiding Big Rip singularities, and yielding matter dominated era through the stabilization of the spinor pressure via spin contribution. The stabilization in spinor pressure leads to neglecting it as compared to the increasing energy density, and constituting a matter dominated stable expansion epoch.

physics.gen-ph↗

arXiv2016

Coupling q-deformed dark energy to dark matter

We propose a novel coupled dark energy model which is assumed to occur as a q-deformed scalar field and investigate whether it will provide an expanding universe phase. We consider the q-deformed dark energy as coupled to dark matter inhomogeneities. We perform the phase-space analysis of the model by numerical methods and find the late-time accelerated attractor solutions. The attractor solutions imply that the coupled q-deformed dark energy model is consistent with the conventional dark energy models satisfying an acceleration phase of universe. At the end, we compare the cosmological parameters of deformed and standard dark energy models and interpret the implications.

gr-qc↗

arXiv2016

Solution of deformed Einstein equations and quantum black holes

Recently one and two-parameter deformed Einstein equations have been studied for extremal quantum black holes which have been proposed to obey deformed statistics by Strominger. In this study, we give a deeper insight to the deformed Einstein equations and consider the solutions of these equations for the extremal quantum black holes. We then represent the implications of the solutions, such that the deformation parameters lead the charged black holes to have a smaller mass than the usual Reissner-Nordström black holes. This reduction in mass of a usual black hole can be considered as a transition from classical to quantum black hole regime.

physics.gen-ph↗