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Sisir Roy

Publications and source records attributed to Sisir Roy.

At least 19 recordsLinked to original sources
arXiv2024

Quantized Redshift and its significance for recent observations

With the recent observational evidence in extra galactic astronomy, the interpretation of the nature of quasar redshift continues to be a research interest. Very high redshifts are being detected for extragalactic objects that are presumably very distant and young while also exhibiting properties that are characteristic of a more mature galaxy such as ours. According to Halton Arp and Geoffrey Burbidge, redshift disparities consist of an intrinsic component and are related to an evolutionary process. Karlsson observed redshift periodicity at integer multiples of 0.089 in log scale and Burbidge observed redshift periodicity at integer multiples of 0.061 in linear scale. Since Singular Value Decomposition (SVD) based periodicity estimation is known to be superior for noisy data sets, especially when the data contains multiple harmonics and overtones, mainly irregular in nature, we have chosen it to be our primary tool for analysis of the quasar-galaxy pair redshift data. We have observed a fundamental periodicity of 0.051 with a confidence interval of 95% in linear scale with the site-available Sloan Digital Sky Survey data release 7 (SDSS DR7) quasar-galaxy pair data set. We have independently generated quasar-galaxy pair data sets from both 2dF and SDSS and found fundamental periodicities of 0.077 and 0.089 in log scale with a confidence interval of 95%.

astro-ph.GA↗
arXiv2022

Redshift periodicity and its significance for Recent observation

Recent observational evidence in extra galactic astronomy, the interpretation of the nature of quasar redshift continues to be research interest. Spectrum observation of high redshift quasar is young in nature. Observational evidence discuss on physical interpretation of redshift periodicity with statistical confirmation. Karlsson observed redshift periodicity at integer multiples of 0.089 in log scale and Burbidge observed redshift periodicity integer multiple of 0.061 in linear scale .Data analysis is important in order to form correct interpretations of the observed phenomena. Since Singular value decomposition (SVD) based periodicity estimation is known to be superior for noisy data sets, especially when the data contains multiple harmonics and overtones, mainly irregular in nature, we have chosen it to be our primary tool for analysis of the quasar-galaxy pair redshift data. Kernel density estimation has been performed for estimating the bin width as proper computation of this quantity is crucial for the correctness of the analysis and prevention of over smoothing of the data.We observed fundamental periodicity to be an integer multiple of 0.063 and 0.0604 using method1 and method2 in the transformed quasar redshift data with 95% confidence interval in linear scale. Our results clearly establish that redshift is quantized for quasar-galaxy pair data and its histogram exhibits periodic peak(s). At last briefly discussed on physical interpretation of quantized redshift for quasar and galaxy.Hoyle Narlikar theory of gravity explain the Mystery in recent observation.

astro-ph.CO↗
arXiv2017

New Empirical Evidence on Disjunction Effect and Cultural Dependence

We perform new experiment using almost the same sample size considered by Tversky and Shafir to test the validity of classical probability theory in decision making. The results clearly indicate that the disjunction effect depends also on culture and more specifically on gender (females rather than males). We did more statistical analysis rather that putting the actual values done by previous authors. We propose different kind of disjunction effect i.e. strong and weak based on our statistical analysis.

q-bio.NC↗
arXiv2015

Quantum Path predictability for an electronic Mach-Zehnder interferometer in presence of environment induced Decoherence and Quantum Erasing process

In this paper, we have estimated the temperature dependent path predictability for an electronic Mach-Zehnder interferometer. The increment of path predictability can directly be associated with stronger decoherence process. We have also theoretically predicted that placing two detectors in both the paths, which are at the same equilibrium temperature with the system, erases all the memory of path information and hence acts like a quantum eraser.

quant-ph↗
arXiv2014

Temperature dependent Zeno time for a two level atom tunneling through a thermal magnetic barrier in the framework of weak measurement

The Zeno time has been calculated for a metastable two level atom tunneling through a interacting thermal magnetic field. The process of weak measurement has been utilized for the the estimation of the timescale. The temperature dependence of the Zeno time has been shown. From the calculation it is evident that the Zeno time decreases with the increase of temperature. Moreover, the result restricts the Zeno time to a maximum limiting value, irrespective of how frequent is the measurement process.

quant-ph↗
arXiv2013

Laser trapping of ions and asymptotic minimization of Decoherence

Decoherence time has been calculated for an optical ion trap of Be atoms in a bistable potential model. Comparison has been made between decoherence time and Zeno time for double well potential as a special case. Zeno time is considered as a lower limit of decoherence time for sustainable quantum coherence. Equality of the respective timescales provides a certain transitional temperature, below which decoherence can be asymptotically minimized.

quant-ph↗
arXiv2013

Quatum Thermodynamics and the coherence in Ion channels

We showed that quantum mechanical superposition can sustain in the process of ion transfer in protein membrane for a substantial period, in spite of the presence of the interactions with environmental modes of molecular vibration. The spectral temperature, as defined in quantum thermodynamical framework plays a significant role in maintaining the coherence. The ratio of decoherence time and dwell time has been calculated, which can be directly related to the degree of coherence. The results shead new light to build quantum information system of entangled ionic states in the voltage gated biological channels.

quant-ph↗
arXiv2012

Hartman effect and dissipative quantum systems

The dwell time for dissipative quantum system is shown to increase with barrier width. It clearly precludes Hartman effect for dissipative systems. Here calculation has been done for inverted parabolic potential barrier.

quant-ph↗
arXiv2012

Weak measurement and Zeno time in a dissipative environment

A generalized expression for weak value of dwell time in dissipative systems has been constructed using the approach of Caldirola and Montaldi. An approximate measure of Zeno time has been found taking an asymmetric double well potential. Atomic tunneling between two surfaces is taken as a practical example. The formalism can be used for any solvable potential with exact or approximate energy eigenvalues.

quant-ph↗
arXiv2012

Weak value of Dwell time for Quantum Dissipative spin-1/2 System

The dwell time is calculated within the framework of time dependent weak measurement considering dissipative interaction between a spin half system and the environment. Caldirola and Montaldi's method of retarded Schroedinger equation is used to study the dissipative system. The result shows that inclusion of dissipative interaction prevents zero time tunneling.

quant-ph↗
arXiv2009

Fast Bayesian Semiparametric Curve-Fitting and Clustering in Massive Data With Application to Cosmology

Recent technological advances have led to a flood of new data on cosmology rich in information about the formation and evolution of the universe, e.g., the data collected in Sloan Digital Sky Survey (SDSS) for more than 200 million objects. The analyses of such data demand cutting edge statistical technologies. Here, we have used the concept of mixture model within Bayesian semiparametric methodology to fit the regression curve with the bivariate data for the apparent magnitude and redshift for Quasars in SDSS (2007) catalogue. Associated with the mixture modeling is a highly efficient curve-fitting procedure, which is central to the application considered in this paper. Moreover, we adopt a new method for analysing the posterior distribution of clusterings, also generated as a by-product of our methodology. The results of our analysis of the cosmological data clearly indicate the existence of four change points on the regression curve andposssibiltiy of clustering of quasars specially at high redshift. This sheds new light not only on the issue of evolution, existence of acceleration or decceleration and environment around quasars at high redshift but also help us to estimate thecosmological parameters related to acceleration or decceleration.

astro-ph.CO↗
arXiv2008

Quantum Vacuum and a Matter - Antimatter Cosmology

A model of the universe as proposed by Allen Rothwarf based upon a degenerate Fermion fluid composed of polarizable particle-antiparticle pairs leads to a big bang model of the universe where the velocity of light varies inversely with the square root of cosmological time, t. This model is here extended to predict a decelerating expansion of the universe and to derive the Tully-Fisher law describing the flat rotation curves of spiral galaxies. The estimated critical acceleration parameter, aoR, is compared to the experimental, critical modified Newtonian Dynamics (MOND) cosmological acceleration constant, obtained by fitting a large number of rotation curves. The present estimated value is much closer to the experimental value than that obtained with the other models. This model for aR(t) allows the derivation of the time dependent radius of the universe as a function of red shift Other cosmological parameters such as the velocity of light, Hubble's constant, the Tully-Fisher relation, and the index of refraction of the aether can also be expressed in terms of redshift. This is compared with the statistical fitting for Veron-Cetty data (2006) for quasar red shifts and good agreement is found. This model also determines the time and/or redshift dependence of certain electromagnetic parameters, i.e., the permittivity; the permeability ; and index of refraction of free space. These are found to be useful in various cosmological theories dealing with light passing through media in motion.

astro-ph↗
arXiv2008

Non Markovian Noise mediated through Anamolous Diffusion within Ion Channels

It is quite clear from a wide range of experiments that gating phenomena of ion channels is inherently stochastic. It has been discussed using BD simulations in a recent paper that memory effects in ion transport is negligible, unless the barrier height is high. In this brief report we like to state using Differential Stochastic Methods (DSM's) that the Markovian property of exponential dwell times do indeed give rise to a high barrier, which in turn indicates that memory effects need not be ignored. We have thus constructed a Generalized Langevin Equation which contains a combination of Non Markovian at different time scales & Markovian processes and develop an algorithm to describe the scheme of events. We see that the oscillatory function behaviour with exponential decay is obtained in the Markovian limit and two distinct time scales corresponding to the processes of diffusion & drift may be obtained from preliminary simulation results. We propose that the results need much more inspection and it will be worthwhile to reproduce using MD simulations. The most important idea which we like to propose in this paper is that the rise of time scales and memory effects may be inherently related to the differential behaviour of shear viscosity in the cytoplasm & extracellular matrix.

q-bio.NC↗
arXiv2008

Dark Matter and Supersolidity

The origin of collisionless cold dark matter has been traced back to its origin to the supersolid model of quantum vacuum.

physics.gen-ph↗
arXiv2007

Co-operativity in neurons and the role of noise in brain

In view of some recent results in case of the dopaminergic neurons exhibiting long range correlations in VTA of the limbic brain we are interested to find out whether any stochastic nonlinear response may be reproducible in the nano scales usimg the results of quantum mechanics. We have developed a scheme to investigate this situation in this paper by taking into consideration the Schrodinger equation (SE) in an arbitrary manifold with a metric, which is in some sense a special case of the heat kernel equation. The special case of this heat kernel equation is the diffusion equation, which may reproduce some key phenomena of the neural activities. We make a dual equivalent circuit model of SE and incorporate non commutativity and noise inside the circuit scheme. The behaviour of the circuit elements with interesting limits are investigated. The most bizarre part is the long range response of the model by dint of the Central Limit Theorem, which is responsible for coherent behaviour of a large assembly of neurons.

q-bio.NC↗
arXiv2007

Dynamic Multiple Scattering, Frequency Shift and Possible Effects on Quasar Astronomy

The shifting of spectral lines due to induced correlation effect, discovered first by Wolf for the single scattering case which mimics the Doppler mechanism has been extended and developed further by the present authors known as Dynamic Multiple scattering(DMS). We have explored DMS theory for explaining anomalous redshifts in quasars. Our recent work, based on the statistical analysis of the Véron-Cetty data(2003) supports that quasar redshifts fit the overall Hubble expansion law, as in the case of galaxies, for z less than equal to 0.295 but not for higher redshifts, indicating clearly the inadequacy of the Doppler effect as the sole mechanism in explaining the redshifts for high redshift quasars for z greater than equal to 0.295. We found that the redshift posseses an additive, discordant component due to frequency shifting from the correlation induced mechanism which increases gradually for ~ 0.295 < z < 3.0, however, appearing to follow the evolutionary picture of the universe with absolute dependence on the physical characteristics i.e., environmental aspects of the relevant sources through which the light rays pass, after being multiply scattered.

astro-ph↗
arXiv2006

Relevance of Quantum Mechanics in Circuit Implementation of Ion channels in Brain Dynamics

With an increasing amount of experimental evidence pouring in from neurobiological investigations, it is quite appropriate to study viable reductionist models which may explain some of the features of brain activities. It is now quite well known that the Hodgkin-Huxley (HH) Model has been quite successful in explaining the neural phenomena. The idea of circuit equivalents and the membrane voltages corresponding to neurons have been remarkable which is essentially a classical result. In view of some recent results which show that quantum mechanics may be important at suitable length scales inside the brain, the question which becomes quite important is to find out a proper quantum analogue of the HH scheme which will reduce to the well known HH model in a suitable limit. From the ideas of neuro-manifold and the relevance of quantum mechanics at some length scales in the ion channels, we investigate this situation in this paper by taking into consideration the Schrödinger equation in an arbitrary manifold with a metric, which is in some sense a special case of the heat kernel equation. The next important approach we have taken in order to bring about it's relevance in brain studies and to make connection with HH models is to find out a plausible circuit equivalents of it. What we do realize is that for a proper quantum mechanical description and it's circuit implementation of the same we need to incorporate the non commutativity inside the circuit model. It has been realized here that the metric is a dynamical entity governing space time and for considering equivalent circuits it plays a very distinct role. We have used the methods of stochastic quantization and have constructed a specific case here and see that HH model inductances gets renormalized in the quantum limit.

q-bio.NC↗