SHOUVIK SADHUKHAN | Indian Institute of Space Science and Technology, Trivandrum, India (original) (raw)

Books by SHOUVIK SADHUKHAN

Research paper thumbnail of RESEARCH COPY

it is about an experimental phenomena

Papers by SHOUVIK SADHUKHAN

Research paper thumbnail of Birefringence Measurement using Geometric Phase Shift Algorithm

Social Science Research Network, 2024

Research paper thumbnail of Thickness Non-Uniformity Metrology using Geometric Phase Shifting Algorithm

Social Science Research Network, 2024

Research paper thumbnail of Polarizing Beam Splitter Coupled Mach-Zehnder Interferometer design for Geometric Phase Shift Measurement

Social Science Research Network, Dec 31, 2022

Research paper thumbnail of Spectral Switch Anomalies in Sagnac Interferometer with respect to Galilean Frame

arXiv (Cornell University), Apr 13, 2022

We report the spectral switch shift around spectral anomalies in a gyroscopic Sagnac interferomet... more We report the spectral switch shift around spectral anomalies in a gyroscopic Sagnac interferometer which is normally used to calibrate the angular momentum of a gyroscope. The spectral shift in the rotating gyroscope is explained with respect to the longitudinal Doppler shift of the counter propagating beams in the Sagnac interferometer.

Research paper thumbnail of Multiple fluid theory of cosmic evolution and its thermodynamic analysis

Indian Journal of Physics, May 25, 2022

In this paper we have discussed the modified gravity and scalar field DE model specifically DBI e... more In this paper we have discussed the modified gravity and scalar field DE model specifically DBI essence model with the analysis of thermodynamics during cosmological evolution. We have used the modified gravity with the form (,) = + 2 in our calculations. The basic aim behind this paper is to discuss a theory that unifies modified gravity with DE models including the solutions of some cosmological problems like thermodynamics energy conditions violation problems, finite time future singularity problems, initial singularity problem, Cosmic inflation problem, decelerated expansion problem, graceful exit problem, reheating problem, bouncing nature problem, phase transformation-spontaneous symmetry breaking problem, negative heat capacity paradox problem and obviously the present day universe problems (Continuously decreasing temperature problem, present day DE dominated expansion problem). We have established the viscous effects (both positive and negative viscosity) in our calculation and discussed the negative-positive viscosity by introducing two special type of energy cycles. Finally, we have discussed the stability conditions for universe evolution through cosmic perturbation and resolved the instability problems. We have also shown the state finder trajectories for both with and without viscous fluid on the basis of our calculations to compare our research with the results of other independent DE models.

Research paper thumbnail of Quintessence Model with Bulk Viscosity and Some Predictions on the Coefficient of Bulk Viscosity and Gravitational Constant

Social Science Research Network, 2023

Research paper thumbnail of Binary Interaction with Multiple Fluid Type Cosmology under Modified Gravity Frame

Social Science Research Network, 2023

In the present chapter, we have established multiple fluid cosmological models under interaction ... more In the present chapter, we have established multiple fluid cosmological models under interaction scenarios. The interaction model we have established is a binary type of interaction scenario where three types of fluids are bound with interaction. We have incorporated variable gravitational constant and variable cosmological constant. The whole work has proceeded with modified gravity geometry where the modified effect over Einstein's gravity acts like a variable cosmological constant. We have used linear dark matter (DM), inhomogeneous fluid and a new type of nonlinear model as interacting components. We have discussed the cosmic phases only with fluid dynamical approaches i.e., through the scale factor variations of effective energy density, pressure, equation of state (EOS) parameter and gravitational constant (Λ).

Research paper thumbnail of Quintessence Model Calculations for Bulkviscous Fluid and Low Value Predictions of Thecoefficient of Bulk Viscosity in General as Well as Modified Gravity With the Form F(R,T)=R+F(T) and F(T)=λT

In this paper we have defined the effect of bulk viscosity on Quintessence model and scaler field... more In this paper we have defined the effect of bulk viscosity on Quintessence model and scaler field potential as well as on classical field. We have shown the same effect for modified gravity with f(R,T)= R+f(T). In the derivation we have predicted the possibility of time dependent evolution of gravitational constant G and anisotropy.

Research paper thumbnail of A Non-Linear Type Equation of State and Cosmic Fluid Dynamics

Social Science Research Network, 2023

In this chapter we have introduced a special type of non-linear equation of state to discuss the ... more In this chapter we have introduced a special type of non-linear equation of state to discuss the cosmological evolution mechanism. The new equation of state is a four parameters model which can be represented as p = Aρ + Bρ 2 − C ρ α where B = Aβ − γ. The evolution of universe have been interpreted by fluid dynamics. The reconstruction of Chaplygin gas and Van-Der-Waals (VDW) fluid equation of states have been done from the parametric analysis of this new non-linear model. Different cosmological phases like Quintom, Quintessence and warm universe have been discussed here. Finally, we have provided a comparative studies of this model with other non-linear fluid solutions.

Research paper thumbnail of Study of Einstein Equivalence Principle with Sagnac Effect in Lorentz and Galilean Frame

Social Science Research Network, 2023

Sagnac effect has been studied in terms of Gyroscopic system in both Lorentz frame as well as fla... more Sagnac effect has been studied in terms of Gyroscopic system in both Lorentz frame as well as flat Einstein frame. The Einstein equivalence principle has been used to determine the phase shift due to pseudo force in the transformation from rotating earth frame to stationary frame. A polychromatic broadband source has been considered for the discussion. The Langevin-Landau-Lifschitz metric has been used during the incorporation of General theory of relativity. The square type sagnac interferometer has been used in theory establishment.

Research paper thumbnail of Spectral switch anomalies in a Sagnac interferometer with respect to a Galilean frame

Journal of the Optical Society of America, Oct 12, 2022

We report the spectral switch shift around spectral anomalies in a gyroscopic Sagnac interferomet... more We report the spectral switch shift around spectral anomalies in a gyroscopic Sagnac interferometer which is normally used to calibrate the angular momentum of a gyroscope. The spectral shift in the rotating gyroscope is explained with respect to the longitudinal Doppler shift of the counter propagating beams in the Sagnac interferometer.

Research paper thumbnail of Coupling between DBI dark energy model and f(Q) gravity and its effect on condensed body mass accretion

Modern Physics Letters A, Sep 14, 2022

In this paper, we have studied the reconstruction formalism of the Dirac–Born–Infeld (DBI)-essenc... more In this paper, we have studied the reconstruction formalism of the Dirac–Born–Infeld (DBI)-essence scalar field model in the background of non-metric gravity or [Formula: see text] gravity which is controlled by the deformation or non-metricity scale [Formula: see text]. The deformation is caused by the fifth dimension of wrapped compact spaces in brane cosmology. The fifth dimension of that wrapped space is controlled by the D-Brane tension [Formula: see text]. Hence, we have reconstructed the formalism of DBI scalar field energy densities and pressures using the coupling of deformation geometry and brane scalar fields, i.e. [Formula: see text] and DBI-Scalar fields. The accretion of dark energy onto black holes and wormholes and its critical analysis had been studied with this reconstructed model. The validity of energy conditions has been studied. We have assumed four types of singularity resolutions of the scale factor to investigate the nature of the black hole and wormhole masses due to accretion. Graphically, the physical quantities like mass, kinetic and potential energies have been analyzed for DBI-essence model in the background of [Formula: see text] gravity.

Research paper thumbnail of Condensed body mass accretion with DBI-essence dark energy and its reconstruction with f(Q) gravity

arXiv (Cornell University), Sep 22, 2021

We have studied the reconstruction formalism of the Dirac-Born-Infeld (DBI)-essence scalar field ... more We have studied the reconstruction formalism of the Dirac-Born-Infeld (DBI)-essence scalar field model in the background of non-metric gravity or f (Q) gravity which is controlled by the deformation or non-metricity scale Q. The deformation is caused by the fifth dimension of wrapped compact spaces in brane cosmology. The fifth dimension of that wrapped space is controlled by the D-brane tension T (φ). Hence, we have reconstructed the formalism of DBI scalar field energy densities and pressures using the coupling of deformation geometry and brane scalar fields, i.e., f (Q) and DBI-Scalar fields. The accretion of dark energy onto black holes and wormholes and its critical analysis have been studied with this reconstructed model. The validity of energy conditions has been studied. We have assumed four types of singularity resolutions of the scale factor to investigate the nature of the black hole and wormhole masses due to accretion. Graphically, the physical quantities like mass, kinetic and potential energies have been analyzed for DBI-essence model in the background of f (Q) gravity.

Research paper thumbnail of A theoretical model of Dark Energy Stars in Einstein-Gauss-Bonnet Gravity

arXiv (Cornell University), Jun 16, 2021

Dark energy stars research is an issue of great interest since recent astronomical observations w... more Dark energy stars research is an issue of great interest since recent astronomical observations with respect to measurements in distant supernovas, cosmic microwave background and weak gravitational lensing confirm that the universe is undergoing a phase of accelerated expansion and this cosmological behavior is caused by the presence of a cosmic fluid which has a strong negative pressure that allows to explain the expanding universe. In this paper, we obtained new relativistic stellar configurations within the framework of Einstein-Gauss-Bonnet (EGB) gravity considering negative anisotropic pressures and the equation of state r p   where r p is the radial pressure, ω is the dark energy parameter, and ρ is the dark energy density. We have chosen a modified version of metric potential proposed by Korkina-Orlyanskii (1991). For the new solutions we checked that the radial pressure, metric coefficients, energy density and anisotropy are well defined and are regular in the interior of the star and are dependent of the values of the Gauss-Bonnet coupling constant. The solutions found can be used in the development of dark energy stars models satisfying all physical acceptability conditions, but the causality condition and strong energy condition cannot be satisfied.

Research paper thumbnail of Thermodynamics and energy condition analysis for Van-Der-Waals EOS without viscous cosmology

Physica Scripta, Nov 8, 2021

In this paper we have studied Van-Der-Waals fluid system with the generalized EOS as = (,) + () a... more In this paper we have studied Van-Der-Waals fluid system with the generalized EOS as = (,) + () as discussed in the recent works of Kremer, G.M [1, 4], Vardiashvili, G [2], Jantsch, R.C [3], Capozziello, S [5]. (,) and () are functions of energy density and time that are different for the three types of Van der Waals fluid which are one parameter model, two parameters model and three parameters model. We have studied the changes in the parameters for different cosmic phases. We have also investigated the thermodynamics and the stability conditions for these three models. Finally, we have resolved the finite time future singularity problems.

Research paper thumbnail of Energy conditions for inhomogeneous EOS and its thermodynamics analysis with the resolution on finite time future singularity problems

International Journal of Geometric Methods in Modern Physics, May 24, 2021

In this paper we study two different cases of inhomogeneous EOS of the form p = ()ρ + w 1 (,). We... more In this paper we study two different cases of inhomogeneous EOS of the form p = ()ρ + w 1 (,). We derive the energy density of dark fluid and dark matter component for both the cases. Further we calculate the evolution of energy density, gravitational constant and cosmological constant. We also explore the finite time singularity and thermodynamic stability conditions for the two cases of EOS. Finally, we discuss the thermodynamics of inhomogeneous EOS with the derivation of internal energy, Temperature and entropy and also show that all the stability conditions are satisfied for the two cases of EOS.

Research paper thumbnail of Geometric Phase Shift in Michelson Interferometer with Polarizing Beam Splitter

Research paper thumbnail of Gyro-Sensor and Spectral Interferometry

Research paper thumbnail of Thermodynamic analysis for Non-linear system (Van-der-Waals EOS) with viscous cosmology

European Physical Journal C, Oct 1, 2021

The following paper is motivated by the recent works of Kremer [

Research paper thumbnail of RESEARCH COPY

it is about an experimental phenomena

Research paper thumbnail of Birefringence Measurement using Geometric Phase Shift Algorithm

Social Science Research Network, 2024

Research paper thumbnail of Thickness Non-Uniformity Metrology using Geometric Phase Shifting Algorithm

Social Science Research Network, 2024

Research paper thumbnail of Polarizing Beam Splitter Coupled Mach-Zehnder Interferometer design for Geometric Phase Shift Measurement

Social Science Research Network, Dec 31, 2022

Research paper thumbnail of Spectral Switch Anomalies in Sagnac Interferometer with respect to Galilean Frame

arXiv (Cornell University), Apr 13, 2022

We report the spectral switch shift around spectral anomalies in a gyroscopic Sagnac interferomet... more We report the spectral switch shift around spectral anomalies in a gyroscopic Sagnac interferometer which is normally used to calibrate the angular momentum of a gyroscope. The spectral shift in the rotating gyroscope is explained with respect to the longitudinal Doppler shift of the counter propagating beams in the Sagnac interferometer.

Research paper thumbnail of Multiple fluid theory of cosmic evolution and its thermodynamic analysis

Indian Journal of Physics, May 25, 2022

In this paper we have discussed the modified gravity and scalar field DE model specifically DBI e... more In this paper we have discussed the modified gravity and scalar field DE model specifically DBI essence model with the analysis of thermodynamics during cosmological evolution. We have used the modified gravity with the form (,) = + 2 in our calculations. The basic aim behind this paper is to discuss a theory that unifies modified gravity with DE models including the solutions of some cosmological problems like thermodynamics energy conditions violation problems, finite time future singularity problems, initial singularity problem, Cosmic inflation problem, decelerated expansion problem, graceful exit problem, reheating problem, bouncing nature problem, phase transformation-spontaneous symmetry breaking problem, negative heat capacity paradox problem and obviously the present day universe problems (Continuously decreasing temperature problem, present day DE dominated expansion problem). We have established the viscous effects (both positive and negative viscosity) in our calculation and discussed the negative-positive viscosity by introducing two special type of energy cycles. Finally, we have discussed the stability conditions for universe evolution through cosmic perturbation and resolved the instability problems. We have also shown the state finder trajectories for both with and without viscous fluid on the basis of our calculations to compare our research with the results of other independent DE models.

Research paper thumbnail of Quintessence Model with Bulk Viscosity and Some Predictions on the Coefficient of Bulk Viscosity and Gravitational Constant

Social Science Research Network, 2023

Research paper thumbnail of Binary Interaction with Multiple Fluid Type Cosmology under Modified Gravity Frame

Social Science Research Network, 2023

In the present chapter, we have established multiple fluid cosmological models under interaction ... more In the present chapter, we have established multiple fluid cosmological models under interaction scenarios. The interaction model we have established is a binary type of interaction scenario where three types of fluids are bound with interaction. We have incorporated variable gravitational constant and variable cosmological constant. The whole work has proceeded with modified gravity geometry where the modified effect over Einstein's gravity acts like a variable cosmological constant. We have used linear dark matter (DM), inhomogeneous fluid and a new type of nonlinear model as interacting components. We have discussed the cosmic phases only with fluid dynamical approaches i.e., through the scale factor variations of effective energy density, pressure, equation of state (EOS) parameter and gravitational constant (Λ).

Research paper thumbnail of Quintessence Model Calculations for Bulkviscous Fluid and Low Value Predictions of Thecoefficient of Bulk Viscosity in General as Well as Modified Gravity With the Form F(R,T)=R+F(T) and F(T)=λT

In this paper we have defined the effect of bulk viscosity on Quintessence model and scaler field... more In this paper we have defined the effect of bulk viscosity on Quintessence model and scaler field potential as well as on classical field. We have shown the same effect for modified gravity with f(R,T)= R+f(T). In the derivation we have predicted the possibility of time dependent evolution of gravitational constant G and anisotropy.

Research paper thumbnail of A Non-Linear Type Equation of State and Cosmic Fluid Dynamics

Social Science Research Network, 2023

In this chapter we have introduced a special type of non-linear equation of state to discuss the ... more In this chapter we have introduced a special type of non-linear equation of state to discuss the cosmological evolution mechanism. The new equation of state is a four parameters model which can be represented as p = Aρ + Bρ 2 − C ρ α where B = Aβ − γ. The evolution of universe have been interpreted by fluid dynamics. The reconstruction of Chaplygin gas and Van-Der-Waals (VDW) fluid equation of states have been done from the parametric analysis of this new non-linear model. Different cosmological phases like Quintom, Quintessence and warm universe have been discussed here. Finally, we have provided a comparative studies of this model with other non-linear fluid solutions.

Research paper thumbnail of Study of Einstein Equivalence Principle with Sagnac Effect in Lorentz and Galilean Frame

Social Science Research Network, 2023

Sagnac effect has been studied in terms of Gyroscopic system in both Lorentz frame as well as fla... more Sagnac effect has been studied in terms of Gyroscopic system in both Lorentz frame as well as flat Einstein frame. The Einstein equivalence principle has been used to determine the phase shift due to pseudo force in the transformation from rotating earth frame to stationary frame. A polychromatic broadband source has been considered for the discussion. The Langevin-Landau-Lifschitz metric has been used during the incorporation of General theory of relativity. The square type sagnac interferometer has been used in theory establishment.

Research paper thumbnail of Spectral switch anomalies in a Sagnac interferometer with respect to a Galilean frame

Journal of the Optical Society of America, Oct 12, 2022

We report the spectral switch shift around spectral anomalies in a gyroscopic Sagnac interferomet... more We report the spectral switch shift around spectral anomalies in a gyroscopic Sagnac interferometer which is normally used to calibrate the angular momentum of a gyroscope. The spectral shift in the rotating gyroscope is explained with respect to the longitudinal Doppler shift of the counter propagating beams in the Sagnac interferometer.

Research paper thumbnail of Coupling between DBI dark energy model and f(Q) gravity and its effect on condensed body mass accretion

Modern Physics Letters A, Sep 14, 2022

In this paper, we have studied the reconstruction formalism of the Dirac–Born–Infeld (DBI)-essenc... more In this paper, we have studied the reconstruction formalism of the Dirac–Born–Infeld (DBI)-essence scalar field model in the background of non-metric gravity or [Formula: see text] gravity which is controlled by the deformation or non-metricity scale [Formula: see text]. The deformation is caused by the fifth dimension of wrapped compact spaces in brane cosmology. The fifth dimension of that wrapped space is controlled by the D-Brane tension [Formula: see text]. Hence, we have reconstructed the formalism of DBI scalar field energy densities and pressures using the coupling of deformation geometry and brane scalar fields, i.e. [Formula: see text] and DBI-Scalar fields. The accretion of dark energy onto black holes and wormholes and its critical analysis had been studied with this reconstructed model. The validity of energy conditions has been studied. We have assumed four types of singularity resolutions of the scale factor to investigate the nature of the black hole and wormhole masses due to accretion. Graphically, the physical quantities like mass, kinetic and potential energies have been analyzed for DBI-essence model in the background of [Formula: see text] gravity.

Research paper thumbnail of Condensed body mass accretion with DBI-essence dark energy and its reconstruction with f(Q) gravity

arXiv (Cornell University), Sep 22, 2021

We have studied the reconstruction formalism of the Dirac-Born-Infeld (DBI)-essence scalar field ... more We have studied the reconstruction formalism of the Dirac-Born-Infeld (DBI)-essence scalar field model in the background of non-metric gravity or f (Q) gravity which is controlled by the deformation or non-metricity scale Q. The deformation is caused by the fifth dimension of wrapped compact spaces in brane cosmology. The fifth dimension of that wrapped space is controlled by the D-brane tension T (φ). Hence, we have reconstructed the formalism of DBI scalar field energy densities and pressures using the coupling of deformation geometry and brane scalar fields, i.e., f (Q) and DBI-Scalar fields. The accretion of dark energy onto black holes and wormholes and its critical analysis have been studied with this reconstructed model. The validity of energy conditions has been studied. We have assumed four types of singularity resolutions of the scale factor to investigate the nature of the black hole and wormhole masses due to accretion. Graphically, the physical quantities like mass, kinetic and potential energies have been analyzed for DBI-essence model in the background of f (Q) gravity.

Research paper thumbnail of A theoretical model of Dark Energy Stars in Einstein-Gauss-Bonnet Gravity

arXiv (Cornell University), Jun 16, 2021

Dark energy stars research is an issue of great interest since recent astronomical observations w... more Dark energy stars research is an issue of great interest since recent astronomical observations with respect to measurements in distant supernovas, cosmic microwave background and weak gravitational lensing confirm that the universe is undergoing a phase of accelerated expansion and this cosmological behavior is caused by the presence of a cosmic fluid which has a strong negative pressure that allows to explain the expanding universe. In this paper, we obtained new relativistic stellar configurations within the framework of Einstein-Gauss-Bonnet (EGB) gravity considering negative anisotropic pressures and the equation of state r p   where r p is the radial pressure, ω is the dark energy parameter, and ρ is the dark energy density. We have chosen a modified version of metric potential proposed by Korkina-Orlyanskii (1991). For the new solutions we checked that the radial pressure, metric coefficients, energy density and anisotropy are well defined and are regular in the interior of the star and are dependent of the values of the Gauss-Bonnet coupling constant. The solutions found can be used in the development of dark energy stars models satisfying all physical acceptability conditions, but the causality condition and strong energy condition cannot be satisfied.

Research paper thumbnail of Thermodynamics and energy condition analysis for Van-Der-Waals EOS without viscous cosmology

Physica Scripta, Nov 8, 2021

In this paper we have studied Van-Der-Waals fluid system with the generalized EOS as = (,) + () a... more In this paper we have studied Van-Der-Waals fluid system with the generalized EOS as = (,) + () as discussed in the recent works of Kremer, G.M [1, 4], Vardiashvili, G [2], Jantsch, R.C [3], Capozziello, S [5]. (,) and () are functions of energy density and time that are different for the three types of Van der Waals fluid which are one parameter model, two parameters model and three parameters model. We have studied the changes in the parameters for different cosmic phases. We have also investigated the thermodynamics and the stability conditions for these three models. Finally, we have resolved the finite time future singularity problems.

Research paper thumbnail of Energy conditions for inhomogeneous EOS and its thermodynamics analysis with the resolution on finite time future singularity problems

International Journal of Geometric Methods in Modern Physics, May 24, 2021

In this paper we study two different cases of inhomogeneous EOS of the form p = ()ρ + w 1 (,). We... more In this paper we study two different cases of inhomogeneous EOS of the form p = ()ρ + w 1 (,). We derive the energy density of dark fluid and dark matter component for both the cases. Further we calculate the evolution of energy density, gravitational constant and cosmological constant. We also explore the finite time singularity and thermodynamic stability conditions for the two cases of EOS. Finally, we discuss the thermodynamics of inhomogeneous EOS with the derivation of internal energy, Temperature and entropy and also show that all the stability conditions are satisfied for the two cases of EOS.

Research paper thumbnail of Geometric Phase Shift in Michelson Interferometer with Polarizing Beam Splitter

Research paper thumbnail of Gyro-Sensor and Spectral Interferometry

Research paper thumbnail of Thermodynamic analysis for Non-linear system (Van-der-Waals EOS) with viscous cosmology

European Physical Journal C, Oct 1, 2021

The following paper is motivated by the recent works of Kremer [

Research paper thumbnail of Hamiltonian Formalism of Bianchi Type I Model for Fluid Bulk and Shearing Viscosity

In this paper we will consider the cosmic fluid to be dissipating i.e it has both bulk and sheari... more In this paper we will consider the cosmic fluid to be dissipating i.e it has both bulk and shearing viscosity. We propose the Hamiltonian formalism of Bianchi type 1 cosmological model for cosmic fluid which is dissipating i.e it has both shearing and bulk viscosity. We have considered both the equation of state parameter ω and the cosmological constant Λ as the function of volume V(t) which is defined by the product of three scale factors of the Bianchi type 1 line element. We propose a Lagrangian for the anisotropic Bianchi type-1 model in view of a variable mass moving in a variable potential. We can decompose the anisotropic expansion of Bianchi type 1 in terms of expansion and shearing motion by Lagrangian mechanism. We have considered a canonical transformation from expanding scale factor to scalar field ø which helps us to give the proper classical definition of that scalar field in terms of scale factors of the mentioned model. By this transformation we can express the mass to be moving in a scalar potential field. This definition helps us to explain the nature of expansion of universe during cosmological inflation. We have used large anisotropy(as in the cases of Bianchi models) and proved that cosmic inflation is not possible in such large anisotropy. Therefore we can conclude that the extent of anisotropy is less in case of our universe. Otherwise the inflation theory which explained the limitations of Big Bang cannot be resolved. In the case of bulk and shearing viscous fluid we get the solution of damped harmonic oscillator after the cosmological inflation.Part I contains the calculations of bulk viscous fluids and Part II contains the calculations of bulk and shearing viscous fluid.At the end we have also provided the relation of shearing and expansion.Part III will give the approximation of low viscosity to solve the viscous fluid problem.