arXiv subjects

M. B. Altaie

Publications and source records attributed to M. B. Altaie.

15 recordsLinked to original sources

arXiv2018

Determinism and the Theory of Every Thing

Recently Gerard 't Hooft proposed a structure for a universe overwhelmed with a control by a Theory of Everything (arXiv:1709.02874). He concludes, among many other things, that such a universe could be fully deterministic and that, accordingly, the divine intervention will be eliminated. Here I discuss such a possibility and show that a fully deterministic universe will turn out to become the divine himself, thus verifying the consistency of Einstein's belief.

quant-ph↗

arXiv2018

Emergent Viscosity: An alternative for Dark Matter in Galaxies

We assume that the individual stars which are located at the peripheral parts of the spiral galaxies are experiencing a drag force acting upon them radially. Such a force might be produced by some sort of a dynamically generated viscous medium, and as the stars are in the state of free fall toward the center of the galaxy, then it would balance the centripetal force acting on the star, thus resulting in a terminal velocity. We make no attempt to explain the origin of the assumed drag force or show how it could be generated, but we have tried to test such an assumption by fitting the calculated velocity curves of 18 spiral galaxies with rotation curves obtained from actual observations. Results show remarkable agreements.

astro-ph.GA↗

arXiv2016

Applying Titius-Bode's Law on Exoplanetry Systems

We report the application of Titius-Bode's law on 43 exoplanetary systems containing four or more planets. Due to the fact that most of these systems have their planets located within compact regions extending for less than the semi-major axis of Mercury we found the necessity to scale down the Titius-Bode law in each case. In this short article we present sample calculations for three systems out of the whole set. Results show that all systems studied are verifying the applicability of the law with high accuracy. Consequently our investigation verifies practically the scale invariance of Titius-Bode law. The results of this study buildup the confidence in predicting positions of the exoplanets according to Titius-Bode's law besides enabling diagnosing possible reasons of deviations.

astro-ph.EP↗

arXiv2011

Does the Superluminal Neutrino Uncover Torsion?

I investigate the possibility of the propagation of neutrino with superluminal speed through matter in the context of the relation between gravity, spin and torsion. Using a lemma of Penrose and earlier works on the relation between spin, torsion and gravity I glimpse on a frame work in which superluminal speed of the neutrinos moving through matter become possible. In presence of torsoin neutrinos are found to follow spacelike geodesics by tunneling through the light cone into the spacelike region and consequently appear to have superluminal speed in our timelike world, whereas photons always follow null geodesics. This frame work may set new frontiers for spacetime physics.

gr-qc↗

arXiv2009

A quantum black hole universe

Using the result obtained in a prevoius paper, in which I found an upper limit on the region of particle creation in the vicinity of the event horizon of a Schwarzschild black hole, and by assuming that all the created energy will be absorbed by the black hole, a natural power law for the growth of the event horizon is deduced. This result may explain the existence of galactic black holes with very large masses. Application of this result on cosmological scale shows that if we start with a Planck-sized black hole then the natural growth of such a black hole will produce one with a density equals the present critical density of the universe. Such a black hole universe will be in the state of eternal inflation.

gr-qc↗

arXiv2009

The Friedmann Paradigm: A critical review

The Friedmann paradigm for a dynamical universe emanating from a spacetime singularity is critically reviwed. Quantum effects, playing the essential role at the very early stages, suggests that the universe may follow different course to that presented by the standard Friedmann solutions. The investigation of the back-reaction effect of the vacuum energy of quantized massless matter fields at finite temperatures shows that the original spatial singularity is avoided and that the universe is maintained all times at a critical density. Instead of having a universe that was created at once we have an emergent universe with energy being created continuously so as to maintain the overall density at its critical value. The calculations presented here provide a basis to construct a dynamical model for the universe where all the known problems of the standard big bang can be avioded from start without the need to assume the occurence of an inflation phase.

gr-qc↗

arXiv2009

Re-Creation: A possible interpretation of quantum indeterminism

I discuss some of the main interpretations given to explain the indeterministic nature of quantum measurements and show that all has some loopholes in one corner or another. I propose an alternative interpretation based on the notion of continued re-creation of the physical properties. The rate at which the system is re-created is a measure of the determinism of the measurements. The existence of uncertainties is better explained through this view, the meaning of incompatible observables becomes clearer and with the notion of re-creation and the origin of the Heisenberg uncertainty principle becomes more vivid.

quant-ph↗

arXiv2009

A non-singular universe with vacuum energy

We construct a model for the universe based on the existence of quantum fields at finite temperature in the background of Robertson-Walker spacetime in presence of a non-zero cosmological constant. We discuss the vacuum regime in the light of the results obtained through previous studies of the back-reaction of massless quantum fields in the static Einstein universe, and we argue that an adiabatic vacuum state and thermal equilibrium is achieved throughout this regime. Results shows that such a model can explain many features of the early universe as well as the present universe. The model is free from the basic problems of the standard Friedmann cosmology, and is non-singular but involves a continuous creation of energy at a rate proportional to the size of the universe, which is lower than that suggested by the steady-state cosmology.

gr-qc↗

arXiv2003

Casimir energy for spherical shell in Schwarzchild black hole background

In this paper, we consider the Casimir energy of massless scalar field which satisfy Dirichlet boundary condition on a spherical shell. Outside the shell, the spacetime is assumed to be described by the Schwarzschild metric, while inside the shell it is taken to be the flat Minkowski space. Using zeta function regularization and heat kernel coefficients we isolate the divergent contributions of the Casimir energy inside and outside the shell, then using the renormalization procedure of the bag model the divergent parts are cancelled, finally obtaining a renormalized expression for the total Casimir energy.

gr-qc↗

arXiv2003

The Cardy-Verlinde formula and entropy of Topological Kerr-Newman black holes in de Sitter spaces

In this paper we show that the entropy of cosmological horizon in 4-dimensional Topological Kerr-Newman-de Sitter spaces can be described by the Cardy-Verlinde formula, which is supposed to be an entropy formula of conformal field theory in any dimension. Furthermore, we find that the entropy of black hole horizon can also be rewritten in terms of the Cardy-Verlinde formula for these black holes in de Sitter spaces, if we use the definition due to Abbott and Deser for conserved charges in asymptotically de Sitter spaces. Such result presume a well-defined dS/CFT correspondence, which has not yet attained the credibility of its AdS analogue.

hep-th↗

arXiv2003

Finite-temperature scalar fields and the cosmological constant in an Einstein universe

We study the back reaction effect of massless minimally coupled scalar field at finite temperatures in the background of Einstein universe. Substituting for the vacuum expectation value of the components of the energy-momentum tensor on the RHS of the Einstein equation, we deduce a relationship between the radius of the universe and its temperature. This relationship exhibit a maximum temperature, below the Planck scale, at which the system changes its behaviour drastically. The results are compared with the case of a conformally coupled field. An investigation into the values of the cosmological constant exhibit a remarkable difference between the conformally coupled case and the minimally coupled one.

gr-qc↗

arXiv2002

Back reaction of the neutrino field in an Einstein universe

The back reaction effect of the neutrino field at finite temperature in the background of the static Einstein universe is investigated. A relationship between the temperature of the universe and its radius is found. As in the previously studied cases of the massless scalar field and the photon field, this relation exhibit a minimum radius below which no self-consistent solution for the Einstein field equation can be found. A maximum temperature marks the transition from a vacuum dominated state to the radiation dominated state universe. In the light of the results obtained for the scalar, neutrino and photon fields the role of the back reaction of quantum fields in controling the value of the cosmological constant is briefly discussed.

gr-qc↗

arXiv2001

Quantum black hole inflation

In this paper we follow a new approach for particle creation by a localized strong gravitational field. The approach is based on a definition of the physical vacuum drawn from Heisenberg uncertainty principle. Using the fact that the gravitational field red-shifts the frequency modes of the vacuum, a condition on the minimum stregth of the gravitational field required to achieve real particle creation is derived. Application of this requirement on a Schwartzchid black hole resulted in deducing an upper limit on the region, outside the event horizon, where real particles can be created. Using this regional upper limit, and considering particle creation by black holes as a consequence of the Casimir effect, with the assumption that the created quanta are to be added to the initial energy, we deduce a natural power law for the development of the event horizon, and consequently a logarithmic law for the area spectrum of an inflating black hole. Application of the results on a cosmological model shows that if we start with a Planck-dimensional black hole, then through the process of particle creation we end up with a universe having the presently estimated critical density. Such a universe will be in a state of eternal inflation.

gr-qc↗

arXiv2001

Back-reaction of Quantum fields in an Einstein Universe

We study the back-reaction effects of the finite-temperature scalar field and the photon field in the background of an Einstein universe. In each case we find a relation between the temperature of the universe and its radius. These relations exhibit a minimum radius below which no self-consistent solution for the Einstein field equation can be found. A maximum temperature marks the transition from the vacuum dominated era to the radiation dominated era. An interpretation to this behavior in terms of Bose-Einstein condensation in the case of the scalar field is given.

gr-qc↗

arXiv2000

Boson Condensation in an Einstein Universe

In this paper we investigate the Bose-Einstein condensation of massive spin-1 particles in an Einstein universe. The system is considered under relativistic conditions taking into consideration the possibility of particle-antiparticle pair production. An exact expression for the charge density is obtained, then certain approximations are employed in order to obtain the solutions in closed form. A discussion of the approximations employed in this and other work is given. The effects of finite-size and spin-curvature coupling are emphasized.

gr-qc↗