arXiv subjects

Samina S. Masood

Publications and source records attributed to Samina S. Masood.

At least 19 recordsLinked to original sources

arXiv2026

Multiscale Biophysical Waves (MBW): Conceptual and Theoretical Framework

This paper establishes a conceptual and theoretical framework for multilevel communication between quantum, molecular, cellular, tissue-organ, whole body, and other biophysical spaces. The wave-mechanical description of electromagnetic signaling is developed, detailing how waves move through cellular structures and interact energetically with surrounding biomaterials. These regions transmit and receive partially coherent biomolecular signals within and across cells, tissues, organs, and neural networks, where resonant frequencies interfere, converge and respond. These processes introduce nonlinearities and stochastic delays that shape timing, coherence, and network-level dynamics, and can be integrated within a pragmatic framework linking mathematical modeling of the physical state to experiential outcomes. This contribution stands as an independent theoretical framework: it sets the foundation for the wave mechanical approach to understanding brain function, which may help to develop new methods to prevent aberrant brain behavior. Mathematical derivations of the inter-sector coupling operators and clinical and therapeutic applications are postponed for future work.

physics.bio-ph↗

arXiv2016

Relativistic QED Plasma at Extremely High Temperature

Renormalization scheme of QED (Quantum Electrodynamics) at high temperatures is used to calculate the effective parameters of relativistic plasma in the early universe. Renormalization constants of QED play role of effective parameters of the theory and can be used to determine the collective behavior of the medium. We explicitly show that the dielectric constant, magnetic reluctivity, Debye length and the plasma frequency depend on temperature in the early universe. Propagation speed, refractive index, plasma frequency and Debye shielding length of a QED plasma are computed at extremely high temperatures in the early universe. We also found the favorable conditions for the relativistic plasma from this calculations.

astro-ph.HE↗

arXiv2015

Magnetic Dipole Moment of Neutrino

We recalculate the magnetic moment of neutrinos in a hot and dense medium. The magnetic dipole moment of neutrinos is modified at high temperature and chemical potential. We show that the magnetic dipole moment of electron neutrino does not get a significant contribution from thermal background to meet the cosmological bound. However, chemical potential contribution to the magnetic moment is non-ignorable even when chemical potential is an order of magnitude greater than the electron mass. It is demonstrated that this effect is more significant in the models with an extended Higgs sector through neutrino mixing.

hep-ph↗

arXiv2015

Entanglement in a Jaynes-Cummings Model with Two Atoms and Two Photon Modes

We investigate the conditions of entanglement for a system of two atoms and two photon modes in vacuum, using the Jaynes-Cummings model in the rotating-wave approximation. It is found, by generalizing the existing results, that the strength of entanglement is a periodic function of time. We explicitly show that our results are in agreement with the existing results of entanglement conditions under appropriate limits. Results for the two-atom and two-photon system are generalized to the case of arbitrary values for the atomic energies, corresponding to photon modes frequencies. Though it is apparently a generalization of the existing work, we have considered for the first time both the resonant and nonresonant conditions and found a general equation which could be true for both cases. Moreover, we show that periodicity of the entanglement is a distinct feature of resonant system. Considering the two atoms and two photons system, in detail, we setup an approach which could be generalized for many particle systems and the resulting master equation can also be analyzed.

quant-ph↗

arXiv2014

A von Neumann Entropy Measure of Entanglement Transfer in a Double Jaynes-Cummings Model

We study the entanglement in a system consisting of two non-interacting atoms located in separate cavities, both in their ground states. A single incoming photon has a non-zero probability of entering either of the two cavities. The Jaynes-Cummings interaction in the rotating wave approximation describes the coupling of each atom with the radiation field. We compute and analyze the atom-atom entanglement, the entanglement between the two photon modes, and also the entanglement between each atom and each photon mode. The measure of entanglement is the von Neumann entropy. For the case in which the two atom-photon systems have identical properties, but allowing for non-resonant conditions, the sum of the atom-atom and photon-modes-entanglement is time independent. The effect of detuning is to decrease the strength of the largest entanglement achieved and to shorten the time for it to occur. The results support the fact that the state of the photons after emergence from cavities is entangled, notwithstanding its single-particle nature. In addition, for the case of resonance and identical cavity parameters, we demonstrate that von Neumann entropy is always greater than or equal to the measure of entanglement known as negativity.

quant-ph↗

arXiv2014

Renormalization of QED near Decoupling Temperature

We study the effective parameters of QED near decoupling temperatures and show that the QED perturbative series is convergent, at temperatures below the decoupling temperature. The renormalization constant of QED acquires different values if a system cools down from a hotter system to the electron mass temperature or heats up from a cooler system to the same temperature. At T = m, the first order contribution to the electron selfmass, δm/m is 0.0076 for a heating system and 0.0115 for a cooling system and the difference between two values is equal to 1/3 of the low temperature value and 1/2 of the high temperature value around T~m. This difference is a measure of hot fermion background at high temperatures. With the increase in release of more fermions at hotter temperatures, the fermion background contribution dominates and weak interactions have to be incorporated to understand the background effects.

hep-th↗

arXiv2014

Nucleosynthesis in Hot and Dense Media

We study the finite temperature and density effects on beta decay rates to compute their contributions to nucleosynthesis. QED type corrections to beta decay from the hot and dense background are estimated in terms of the statistical corrections to the self-mass of an electron. For this purpose, we re-examine the hot and dense background contributions to the electron mass and compute its effect to the beta decay rate, helium yield, energy density of the universe as well as the change in neutrino temperature from the first order contribution to the self-mass of electrons during these processes. We explicitly show that the thermal contribution to the helium abundance at T = m of a cooling universe 0.045 % is higher than the corresponding contribution to helium abundance of a heating universe 0.031% due to the existence of hot fermions before the beginning of nucleosynthesis and their absence after the nucleosynthesis, in the early universe. Thermal contribution to helium abundance was a simple quadratic function of temperature, before and after the nucleosynthesis. However, this quadratic behavior was not the same before the decoupling temperature due to weak interactions; so the nucleosynthesis did not even start before the universe had cooled down to the neutrino decoupling temperatures and QED became a dominant theory. It is also explicitly shown that the chemical potential in the core of supermassive and superdense stars affect beta decay and their helium abundance but the background contributions depend on the ratio between temperature and chemical potential and not the chemical potential or temperature only. It has been noticed that temperature plays a role of regulating parameter in an extremely dense systems.

astro-ph.HE↗

arXiv2013

Second order photon loops at finite temperature and charge renormalization

We present two loop corrections to photon self energy at finite temperature in real time formalism. An expression for renormalized coupling constant has been derived in a form that is relevant for all temperature ranges of interest in QED, specifically for temperatures around T \sim m, where m is electron mass. Temperature dependence is mainly contributed by hot fermions at T \ge m. We use the calculations of vacuum polarization to determine the dynamically generated mass of photon, Debye screening length, plasma frequency up to the second order in αas well as the electromagnetic properties of a medium at m \le T \le 2m temperature. For higher temperatures, the existing renormalization scheme does not work well because of the increase in coupling constant. To exactly determine the validity of renormalization scheme, higher order calculations are required. The temperature T \sim m is of specific interest from the point of view of the early universe. Such calculations have acquired more significance recently due to the possibility of producing electron-positron plasmas in laboratory.

hep-th↗

arXiv2013

Second Order Corrections to the Magnetic Moment of Electron at Finite Temperature

Magnetic moment of electron at finite temperature is directly related to the modified electron mass in the background heat bath. Magnetic moment of electron gets modified when it couples with the magnetic field at finite temperature through its temperature dependent physical mass. We show that the magnetic moment of electron becomes a complicated function of temperature and even change its temperature dependent behavior around the energies for primordial nucleosynthesis. We calculate the self-mass induced thermal contributions to the magnetic moment of electron, up to the two loop level, for temperatures valid around the era of primordial nucleosynthesis. A comparison of thermal behavior of the magnetic moment is also quantitatively studied in detail, around the temperatures below and above nucleosynthesis temperature range.

hep-th↗

arXiv2012

QED Near the Decoupling Temperature

We study the effective parameters of QED near the decoupling temperature and show that the QED perturbation theory works perfectly fine at temperatures, below the decoupling temperature. Temperature dependent selfmass of electron, at T=m gives two different values, if approached to the same overlapping point. It ia shown that at $T=m$, change in thermal contribution of the electron selfmass is 1/3 of the low temperature value and 1/2 of the high temperature value. The difference of behavior measures the electron background contributions at T=m. These electrons are emitted through beta decay. This rise in mass affects the QED parameters and change the electromagnetic properties of the medium with temperature also. However, these contributions are ignorable near the decoupling temperature.

hep-ph↗

arXiv2012

Quantum Electrodynamics of Nanosystems

Quantum description of mulitiparticle nano-systems is studied in a hot and dense electromagnetic medium. We use renormalization techniques of quantum field theory to show that the electromagnetic properties like electric permittivity and magnetic permeability depend on the temperature and density of the media. Casimir force also depends upon the physical properties of the medium and becomes a function of these parameters within the nano-systems. We discuss the effect of the Casimir force on the nanosystems in terms of temperature and density of the system. We present carbon nanotubes and biomolecules as examples.

physics.bio-ph↗

arXiv2012

Second Order Thermal Corrections to Vacuum Polarization in QED -- A Covariant approach

We study the electromagnetic properties of a hot medium at temperatures below electron mass. It was observed earlier that the first order hot loop corrections do not affect the electromagnetic properties of hot media due to the absence of self-interaction of photons. However, the second order contributions are found to modify these properties due to the overlapping hot and cold loops. It has also been noticed that the hot loops have to be integrated before the cold ones to establish the order by order cancelation of singularities to ensure renormalizability of the theory. It is also explicitly shown that the perturbative series of QED is still a convergent series in a covariant formalism at low temperatures.

hep-ph↗

arXiv2012

Scattering of Leptons in Hot and Dense Media

We study the propagation of leptons in hot and dense media and estimate the background corrections to the purely leptonic processes in the early universe and in the stellar cores.

hep-ph↗

arXiv2012

Magnetic Moment of Neutrino in Statistical Background

We calculate the magnetic moment of Dirac type of neutrinos in hot and dense background for different ranges of temperature and chemical potential. The properties of neutrinos are studied in the strong magnetic field where the chemical potential of particles is high enough to have more particles than the antiparticles. We show that in this situation, Weyl neutrino seems to explain the neutrino coupling with the magnetic field due to its effective mass which can couple with the magnetic field directly. We also investigate the electromagnetic properties of Weyl neutrino due to its effective mass developed in the strong magnetic field.

hep-ph↗

arXiv2011

Second Order Thermal Corrections to Electron Wavefunction

Second order perturbative corrections to electron wavefunction are calculated here at generalized temperature, for the first time. This calculation is important to prove the renormalizeability of QED through order by order cancellation of singularities at higher order. This renormalized wavefunction could be used to calculate the particle processes in the extremely hot systems such as the very early universe and the stellar cores. We have to re-write the second order thermal correction to electron mass in a convenient way to be able to calculate the wavefunction renormalization constant. A procedure for integrations of hot loop momenta before the cold loop momenta integration is maintained throughout to be able to remove hot singularities in an appropriate way. Our results, not only includes the intermediate temperatures T m (where m is the electron mass), the limits of high temperature T>>m and low temperature T<<m are also retrievable. A comparison is also done with the existing results.

hep-ph↗

arXiv2011

Two Loop Low Temperature Corrections to Electron Self Energy

We recalculate the two loop corrections in the background heat bath using real time formalism. The procedure of the integrations of loop momenta with dependence on finite temperature before the momenta without it, has been followed. We determine the mass and wavefunction renormalization constants in the low temperature limit of QED, for the first time with this preferred order of integrations. The correction to electron mass and spinors in this limit is important in the early universe at the time of primordial nucleosynthesis as well as in astrophysics.

hep-ph↗

arXiv2010

Two-Dimensional Quantum Search Algorithm

Quantum mechanical search induces polynomial speed up in an unsorted database search process. In case of classical linear search the computational time increases with the dimensionality of the query. However, quantum parallelism, inherent to quantum systems, does not let multi-dimensional query processing affect the computational time of the quantum search algorithm. In this letter, a two-dimensional search process has been proposed. It has been shown that a two-dimensional search process can be accomplished without increasing the computational time due to implicit quantum parallelism

quant-ph↗

arXiv2008

Second Order Corrections to QED Coupling at Low Temperature

We calculate the second order corrections to vacuum polarization tensor of photons at low temperatures, i.e; T $\le 10^{10}$ K ($T << m_e$). The thermal contributions to the QED coupling constant are evaluated at temperatures below the electron mass that is $T< m_e$ . Renormalization of QED at these temperatures has explicitly been checked. The electromagnetic properties of such a thermal medium are modified. Parameters like electric permittivity and magnetic permeability of such a medium are no more constant and become functions of temperature.

hep-ph↗