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H. Razmi

Publications and source records attributed to H. Razmi.

At least 19 recordsLinked to original sources
arXiv2021

Is the standard quantum mechanics a completely nondeterministic theory?

It is argued that although quantum theory isn't an absolutely deterministic theory, it is partially deterministic. The approach followed here is in the framework of the standard (Copenhagen interpretation of) quantum mechanics without any additional assumption or alternative interpretation. The argument is based on the conceptual meaning of determinism and by means of some well-known phenomena in the quantum world (measurement of a quantum particle spin, energy values and spatial states of an electron in atoms, the so-called wavefunction collapse problem) which are usually considered in rejecting determinism.

physics.hist-ph↗
arXiv2021

When the Quantum Energy Teleportation is Observable?

We want to investigate when the quantum energy teleportation is observable. The condition for observability is based on the minimum time value determined by the fundamental energy-time uncertainty relation.

quant-ph↗
arXiv2020

Reconstructing William Lane Craig's Explanation of Absolute Time based on Mulla Sadra's Philosophy

After the advent of the theory of special relativity, the existence of absolute time in nature was rejected within the society of physics. In recent decades, William Lane Craig has endeavoured to offer an interpretation of the empirical evidence that support the theory of relativity while maintaining the concept of absolute time. His interpretation, however, is based upon supernatural presuppositions due to which it cannot be accepted as a scientific argument. Here, after explaining Craig's view, we attempt to reconstruct his explanation for absolute time using the concept of general substantial motion of nature, well-known in Mulla Sadra's philosophy as the most important approach in Islamic philosophy; thereby, proving general time for the natural world. Although Craig considers some evidence from modern physics in his reasoning for absolute time, in this paper, after pointing to some evidence, it is discussed that the approach used here better bridges the gap that exists between the metaphysics and the physics of the argument.

physics.hist-ph↗
arXiv2019

Tidal Limit of Stellar Systems in Two-Power Density Models

As the generalization of gravitational effects on the point mass systems, we want to study the tidal effect exerted on an extended stellar system using spherical and axisymmetric elliptical models. Considering the Isochrone and Plummer models for a passing extended stellar system, the tidal distance and the equipotential surface are calculated. The corresponding critical surfaces and maps are plotted in different cases. There are different results some of them may be used in describing stellar systems deformation

astro-ph.GA↗
arXiv2019

Dispersive Property of the Quantum Vacuum and the Speed of Light

We want to study the influence of the quantum vacuum on the light propagation. At first, by working in the standard linear quantum theory of the electromagnetic fields, it is shown that the electric permittivity and the magnetic permeability of the vacuum medium are changed; but, the resulting speed of light isn't modified. Then, taking into account nonlinear effects by considering the Euler-Heisenberg Lagrangian, the corresponding zero point (vacuum) energy and the resulting modification of the speed of light are found up to the first non-vanishing correction.

physics.gen-ph↗
arXiv2017

The Covariant Electromagnetic Casimir Effect for Real Conducting Cylindrical Shells

Using covariant quantization of the electromagnetic field, the Casimir force per unit area experienced by a long conducting cylindrical shell, under both Dirichlet and Neumann boundary conditions, is calculated. The renormalization procedure is based on the plasma cut-off frequency for real conductors. The real case of a gold (silver) cylindrical shell is considered and the corresponding electromagnetic Casimir pressure is computed. It is discussed that the Dirichlet and Neumann problems should be considered separately without adding their corresponding results.

quant-ph↗
arXiv2016

The covariant electromagnetic Casimir effect for real conducting spherical shells

Using the covariant electromagnetic Casimir effect (previously introduced for real conducting cylindrical shells [1]), the Casimir force experienced by a spherical shell, under Dirichlet boundary condition, is calculated. The renormalization procedure is based on the plasma cut-off frequency for real conductors. The real case of a gold (silver) sphere is considered and the corresponding electromagnetic Casimir force is computed. In the covariant approach, there isn't any decomposition of fields to TE and TM modes; thus, we do not need to consider the Neumann boundary condition in parallel to the Dirichlet problem and then add their corresponding results.

physics.gen-ph↗
arXiv2016

Cosmic walls and filaments formation in modified Chaplygin gas cosmology

We want to study the perturbation growth of an initial seed of an ellipsoidal shape in Top-Hat collapse model of structure formation in the Modified Chaplygin gas cosmology. Considering reasonable values of the constants and the parameters of the model under study, it is shown that a very small deviation from spherical symmetry (ellipsoidal geometry) in the initial seed leads to a final highly non-spherical structure which can be considered as a candidate for justifying already known cosmological structures as cosmic walls and filaments.

gr-qc↗
arXiv2016

The Casimir Forces in a Single Conducting Cylindrical Cavity

We want to study the Casimir effect for a single conducting microscopic cylindrical cavity. The mathematical technique is based on the Green function of the geometry of the inside of the cavity, and the integral regularization is based on the plasma frequency cutoff for real conductors. Using the symmetric electromagnetic energy-momentum tensor, in terms of four potential, the total Casimir energy for the inside of the Cavity is calculated. Neglecting the contribution of the external (outside of the cavity) Casimir energy based on the reason recently presented in [1], the forces experienced by the lateral surface of the cavity and its circular bases are calculated. The resulting expressions show that these forces are repulsive. The numerical computation is done for the real problem of a cavity with a basis of a radius in the same order of its height at the scale of 100 nanometers made of the best conducting materials already known.

quant-ph↗
arXiv2015

On the Tidal Evolution and Tails Formation of Disc Galaxies

In this paper, we want to study the tidal effect of an external perturber upon a disc galaxy based on the generalization of already used Keplerian potential. The generalization of the simple ideal Keplerian potential includes an orbital centripetal term and an overall finite range controlling correction. Considering the generalized form of the interaction potential, the velocity impulse expressions resulting from tidal forces are computed; then, using typical real values already known from modern observational data, the evolution of the disc including tidal tails formation is graphically investigated.

physics.gen-ph↗
arXiv2015

The Gott-Kaiser-Stebbins (GKS) Effect in an Accelerated Expanding Universe

We want to find the cosmological constant influence on cosmic microwave background (CMB) temperature due to moving linear cosmic strings. Considering the space-time metric of a linear cosmic string in an accelerated expanding universe, the Gott-Kaiser-Stebbins (GKS) effect, as an important mechanism in producing temperature discontinuity in the CMB, is considered and its modification due to the effect of the cosmological constant is calculated. The result shows that a positive cosmological constant (i.e. the presence of cosmic strings in an accelerated expanding universe) weakens the discontinuity in temperature so that more strong resolution is needed to detect the corresponding influences on the CMB power spectrum and anisotropy.

gr-qc↗
arXiv2015

Is Bayes theorem applicable to all quantum states?

Reconsidering the already known important question that whether all the axioms and theorems in classical theory of probability are applicable to probability functions in quantum theory, we want to show that the so-called Bayes theorem isn't applicable to nonfactorizable quantum entangled states.

physics.gen-ph↗
arXiv2015

Spherical "Top-Hat" Collapse in a Modified Chaplygin Gas Dominated Universe

Considering perturbation growth in spherical Top-Hat model of structure formation in a generalized Chaplygin gas dominated universe, we want to study this scenario with a modified Chaplygin gas model. The evolution of background and collapsed region parameters are found for different cases. The stability of the model and the collapse time rate are considered in different cases. The turn-around redshifts are also computed; the results are in relatively good agreement with current observational data.

gr-qc↗
arXiv2015

Is the Free Vacuum Energy Infinite?

Considering the fundamental cutoff applied by the uncertainty relations' limit on virtual particles' frequency in the quantum vacuum, it is shown that the vacuum energy density is proportional to the inverse of the forth power of the dimensional distance of the space under consideration and thus the corresponding vacuum energy automatically regularized to zero value for an infinitely large free space. This can be used in regularizing a number of unwanted infinities happen in the Casimir effect, the cosmological constant problem and so on without using already known mathematical (not so reasonable) techniques and tricks.

physics.gen-ph↗
arXiv2013

QED Second Order Corrections on the Speed of Light at Low Temperature

We want to study thermal corrections on the speed of light at low temperature considering temperature dependence of photon vacuum polarization tensor at two-loop level in the standard QED. It is found that the heat bath behaves as a dispersive medium to the propagation of light and reduces its speed proprtional to the second order of temperature. Similiraties and differences with already known calculations which are based on Euler-Heisenberg Lagrangian and/or those using temperature dependent electromagnetic properties of the medium are discussed.

hep-ph↗
arXiv2013

The Casimir Atomic Pendulum

We want to introduce an atomic pendulum whose driving force (torque) is due to the quantum vacuum fluctuations. Applying the well-known Casimir-Polder effect to a special configuration (a combined structure of an atomic nanostring and a conducting plate), an atomic pendulum (Casimir atomic pendulum) is designed. Using practically acceptable data corresponding to the already known world of nanotechnology and based on reasonable/reliable numerical estimates, the period of oscillation for the pendulum is computed. This pendulum can be considered as both a new Micro (Nano)-Eelectromechanical system and a new simple vacuum machine. Its design may be considered as a first step towards realizing the visualized vacuum (Casimir) clock!

quant-ph↗
arXiv2012

Mathematical and Physical Examination of the Locality Condition in Bell's Theorem

Using the Clauser-Horne model of Bell's theorem, the locality condition is examined and it is shown the corresponding formulation is equivalent to a factorization process consisting of three stages. The first stage is introduced based on the conditional probability definition in classical theory of probability and the other two stages are based on previously-known relations named as outcome and parameter independence conditions.

quant-ph↗