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Full-Text Articles in Physics

Relativistic Quantum Heat Engine From Uncertainty Relation Standpoint, Pritam Chattopadhyay, Goutam Paul Dec 2019

Relativistic Quantum Heat Engine From Uncertainty Relation Standpoint, Pritam Chattopadhyay, Goutam Paul

Journal Articles

Established heat engines in quantum regime can be modeled with various quantum systems as working substances. For example, in the non-relativistic case, we can model the heat engine using infinite potential well as a working substance to evaluate the efficiency and work done of the engine. Here, we propose quantum heat engine with a relativistic particle confined in the one-dimensional potential well as working substance. The cycle comprises of two isothermal processes and two potential well processes of equal width, which forms the quantum counterpart of the known isochoric process in classical nature. For a concrete interpretation about the relation …


Physics-Driven Dual-Defect Model Fits Of Voltage Step-Up To Breakdown Data In Spacecraft Polymers, Allen Andersen, Jr Dennison Oct 2019

Physics-Driven Dual-Defect Model Fits Of Voltage Step-Up To Breakdown Data In Spacecraft Polymers, Allen Andersen, Jr Dennison

Journal Articles

Overly conservative estimates of breakdown strength can increase the mass and cost of spacecraft electrostatic discharge (ESD) mitigation methods. Improved estimates of ESD likelihood in the space environment require better models of ESD distributions. The purpose of this work is to evaluate our previously proposed dual-defect model of voltage step-up-to-breakdown tests with a case study across four dielectric materials. We predicted that materials best fit by mixed Weibull distributions would exhibit better fits with the dual-defect model compared to a mean field single defect theory. Additional data for biaxially oriented polypropylene (BOPP), polyimide (PI or Kapton) from three sources, and …


Multiplicativity Of Connes' Calculus, Partha Sarathi Chakraborty, Satyajit Guin Oct 2019

Multiplicativity Of Connes' Calculus, Partha Sarathi Chakraborty, Satyajit Guin

Journal Articles

In his book on noncommutative geometry, Connes constructed a differential graded algebra out of a spectral triple. Lack of monoidality of this construction is investigated. We identify a suitable monoidal subcategory of the category of spectral triples and show that when restricted to this subcategory the construction of Connes is monoidal. Richness of this subcategory is exhibited by establishing a faithful endofunctor to this subcategory.


Revisiting Singlino Dark Matter Of The Natural Z 3-Symmetric Nmssm In The Light Of Lhc, Waleed Abdallah, Arindam Chatterjee, Asesh Krishna Datta Sep 2019

Revisiting Singlino Dark Matter Of The Natural Z 3-Symmetric Nmssm In The Light Of Lhc, Waleed Abdallah, Arindam Chatterjee, Asesh Krishna Datta

Journal Articles

Inspired by the fact that relatively small values of the effective higgsino mass parameter of the Z3-symmetric Next-to-Minimal Supersymmetric Standard Model (NMSSM) could render the scenario ‘natural’, we explore the plausibility of having relatively light neutralinos and charginos (the electroweakinos or the ewinos) in such a scenario with a rather light singlino-like Lightest Supersymmetric Particle (LSP), which is a Dark Matter (DM) candidate, and singlet-dominated scalar excitations. By first confirming the indications in the existing literature that finding simultaneous compliance with results from the Large Hadron Collider (LHC) and those from various DM experiments with such light states is, in …


Probing Uncertainty Relations In Non-Commutative Space, Pritam Chattopadhyay, Ayan Mitra, Goutam Paul Aug 2019

Probing Uncertainty Relations In Non-Commutative Space, Pritam Chattopadhyay, Ayan Mitra, Goutam Paul

Journal Articles

In this paper, we compute uncertainty relations for non-commutative space and obtain a better lower bound than the standard one obtained from Heisenberg’s uncertainty relation. We also derive the reverse uncertainty relation for product and sum of uncertainties of two incompatible variables for one linear and another non-linear model of the harmonic oscillator. The non-linear model in non-commutating space yields two different expressions for Schrödinger and Heisenberg uncertainty relation. This distinction does not arise in commutative space, and even in the linear model of non-commutative space.


Secondary Electron Yield Measurements Of Carbon Nanotube Forests: Dependence On Morphology And Substrate, Brian Wood, Jordan Lee, Gregory Wilson, T. -C. Shen, Jr Dennison Aug 2019

Secondary Electron Yield Measurements Of Carbon Nanotube Forests: Dependence On Morphology And Substrate, Brian Wood, Jordan Lee, Gregory Wilson, T. -C. Shen, Jr Dennison

Journal Articles

Total, secondary, and backscatter electron yield data were taken with beam energies between 15 eV and 30 keV, in conjunction with energy emission data, to determine the extent of suppression of yield caused by carbon nanotube (CNT) forest coatings on substrates. CNT forests can potentially lower substrate yield due to both its inherently low-yield, low-atomic number (Z) carbon composition, and its bundled, high-aspect ratio structure. Rough surfaces, and in particular, surfaces with deep high-aspect-ratio voids, can suppress yields, as the electrons emitted from lower lying surfaces are recaptured by surface protrusions rather than escaping the near-surface region. Yields of multilayered …


Wireless Antenna Detection Of Electrostatic Discharge Events, Allen Andersen, Jr Dennison Aug 2019

Wireless Antenna Detection Of Electrostatic Discharge Events, Allen Andersen, Jr Dennison

Journal Articles

Wireless intraspacecraft communication technology is being developed for signal transfer on space missions to save weight and simplify the design. One consideration for this new technology is its interaction with space environmentinduced electrostatic discharges (ESDs). The short time scales of spacecraft ESD events result in broad frequency band signals that can interact with high-frequency wireless antennas. These interactions present a source of signal noise. However, they also present a possibility of in-flight wireless ESD monitoring. We present laboratory measurements of arcing on common spacecraft insulators using commercially available single-band 2.4-GHz and dual-band 2.4-/5.8-GHz Wi-Fi antennas. These wireless detections are shown …


Tracing Cyclic Homology Pairings Under Twisting Of Graded Algebras, Sayan Chakraborty, Makoto Yamashita Jul 2019

Tracing Cyclic Homology Pairings Under Twisting Of Graded Algebras, Sayan Chakraborty, Makoto Yamashita

Journal Articles

We give a description of cyclic cohomology and its pairing with K-groups for 2-cocycle deformation of algebras graded over discrete groups. The proof relies on a realization of monodromy for the Gauss–Manin connection on periodic cyclic cohomology in terms of the cup product action of group cohomology.


Scope Of Self-Interacting Thermal Wimps In A Minimal U(1) D Extension And Its Future Prospects, Rahool Kumar Barman, Biplob Bhattacherjee, Arindam Chatterjee, Arghya Choudhury, Aritra Gupta May 2019

Scope Of Self-Interacting Thermal Wimps In A Minimal U(1) D Extension And Its Future Prospects, Rahool Kumar Barman, Biplob Bhattacherjee, Arindam Chatterjee, Arghya Choudhury, Aritra Gupta

Journal Articles

In this work we have considered a minimal extension of Standard Model by a local U(1) gauge group in order to accommodate a stable (fermionic) Dark Matter (DM) candidate. We have focussed on parameter regions where DM possesses adequate self-interaction, owing to the presence of a light scalar mediator (the dark Higgs), alleviating some of the tensions in the small-scale structures. We have studied the scenario in the light of a variety of data, mostly from dark matter direct searches, collider searches and flavor physics experiments, with an attempt to constrain the interactions of the standard model (SM) particles with …


Quasinormal Mode Spectra For Odd Parity Perturbations In Spacetimes With Smeared Matter Sources, Kumar Das, Souvik Pramanik, Subir Ghosh Jan 2019

Quasinormal Mode Spectra For Odd Parity Perturbations In Spacetimes With Smeared Matter Sources, Kumar Das, Souvik Pramanik, Subir Ghosh

Journal Articles

We have found the quasinormal mode (QNM) frequencies of a class of static spherically symmetric spacetimes having a smeared matter distribution, parametrized by Θ, an inherent length scale. Here, our main focus is on the QNMs for the odd parity perturbation in this background geometry. The results presented here for diffused mass distribution reveal significant changes in the QNM spectrum. This could be relevant for future generation (cosmological) observations, specifically to distinguish the signals of gravitational waves from a nonsingular source in contrast to a singular geometry. We also provide numerical estimates for the Θ-corrected QNM spectrum applicable to typical …


Quantum Isometry Group Of Deformation: A Counterexample, Debashish Goswami, Arnab Mandal Jan 2019

Quantum Isometry Group Of Deformation: A Counterexample, Debashish Goswami, Arnab Mandal

Journal Articles

We give a counterexample to show that the quantum isometry group of a deformed finite dimensional spectral triple may not be isomorphic with a deformation of the quantum isometry group of the undeformed spectral triple.


Environmental Effects On Nonlocal Correlations, Tamal Guha, Bihalan Bhattacharya, Debarshi Das, Some Sankar Bhattacharya, Amit Mukherjee, Arup Roy, Kaushiki Mukherjee, Nirman Ganguly, A. S. Majumdar Jan 2019

Environmental Effects On Nonlocal Correlations, Tamal Guha, Bihalan Bhattacharya, Debarshi Das, Some Sankar Bhattacharya, Amit Mukherjee, Arup Roy, Kaushiki Mukherjee, Nirman Ganguly, A. S. Majumdar

Journal Articles

Environmental interactions are ubiquitous in practical instances of any quantum information processing protocol. The interaction results in depletion of various quantum resources and even complete loss in numerous situations. Nonlocality, which is one particular quantum resource marking a significant departure of quantum mechanics from classical mechanics, meets the same fate. In the present work we study the decay in nonlocality to the extent of the output state admitting a local hidden state model. Using some fundamental quantum channels we also demonstrate the complete decay in the resources in the purview of the Bell–Clauser– Horne–Shimony–Holt inequality and a three-settings steering inequality. …