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Browsing BITS Faculty Publications by Author "Sarkar, Tapomoy Guha"

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Adiabatic modulation of driving protocols in periodically driven quantum systems

Sarkar, Tapomoy Guha; Bandyopadhyay, Jayendra N. (ARXIV, 2024-04)

We consider a periodically driven system where the high-frequency driving protocol consists of a sequence of potentials switched on and off at different instants within a period. We explore the possibility of introducing ...
The CMBR ISW and HI 21 cm cross-correlation angular power spectrum

Sarkar, Tapomoy Guha (IOP, 2009-08)

The late-time growth of large scale structures is imprinted in the CMBR anisotropy through the Integrated Sachs Wolfe (ISW) effect. This is perceived to be a very important observational probe of dark energy. Future ...
CMBR weak lensing and HI 21-cm cross-correlation angular power spectrum

Sarkar, Tapomoy Guha (IOP, 2010-02)

Weak gravitational lensing of the CMBR manifests as a secondary anisotropy in the temperature maps. The effect, quantified through the shear and convergence fields imprint the underlying large scale structure (LSS), geometry ...
Constraining dark energy using the cross correlations of weak lensing with post-reionization probes of neutral hydrogen

Sarkar, Tapomoy Guha (IOP, 2021)

We investigate the prospects of detecting the cross correlation of CMBR weak-lensing convergence field with the large scale tracers of the underlying dark matter distribution in the post-reionization epoch. The cross-correlation ...
Constraining large‐scale H i bias using redshifted 21‐cm signal from the post‐reionization epoch

Sarkar, Tapomoy Guha (OUP, 2012-04)

In the absence of complex astrophysical processes that characterize the reionization era, the 21‐cm emission from neutral hydrogen (H i) in the post‐reionization epoch is believed to be an excellent tracer of the underlying ...
Constraining neutrino mass using the large-scale H i distribution in the post-reionization epoch

Sarkar, Tapomoy Guha (OUP, 2016-07)

The neutral intergalactic medium in the post-reionization epoch allows us to study cosmological structure formation through the observation of the redshifted 21 cm signal and the Lyman α forest. We investigate the possibility ...
Constraining warm dark matter power spectrum using the cross-correlation of HI 21 cm signal and the Lyman-α forest

Sarkar, Tapomoy Guha (IOP, 2019-12)

We have considered the prospects for measuring the cross Warm Dark Matter (WDM) power spectrum of the redshifted HI 21-cm signal and the Lyman-α forest and thereby constraining WDM mass using observations with upcoming ...
Conversion of Emitted Axionic Dark Matter to Photons for Non-Rotating Magnetized Neutron Stars

Sarkar, Tapomoy Guha (ARXIV, 2024-02)

We attempt to find the impact of a modified Tolman Oppenheimer Volkoff (TOV) system of equations on the luminosities of direct photons, neutrinos and axions for a particular axion mass in the presence of a magnetic field. ...
Cosmology and Astrophysics using the Post-Reionization HI

Sarkar, Tapomoy Guha (Springer, 2016-11)

We discuss the prospects of using the redshifted 21-cm emission from neutral hydrogen in the post-reionization epoch to study our Universe. The main aim of the article is to highlight the efforts of Indian scientists in ...
The cross-correlation of redshited 21-cm signal and Lyman-α forest: A cosmological probe

Sarkar, Tapomoy Guha (IOP, 2014)

We have investigated the cross-correlation of the Lyman-α forest and redshifted 21-cm emission as a new observational probe of the large scale structures in the post-reionization era, with a significant advantage that the ...
Cross-correlation of the H i 21-cm signal and Lyα forest: a probe of cosmology

Sarkar, Tapomoy Guha (OUP, 2011-01)

Separating the cosmological redshifted 21-cm signal from foregrounds is a major challenge. We present the cross-correlation of the redshifted 21-cm emission from neutral hydrogen (H i) in the post-reionization era with the ...
The effect of the w-term on the visibility correlation and power spectrum estimation

Sarkar, Tapomoy Guha (OUP, 2010-07)

The visibility–visibility correlation has been proposed as a technique for the estimation of the power spectrum, and used extensively for small field of view observations, where the effect of the w-term is usually ignored. ...
Effective time-independent analysis for quantum kicked systems

Bandyopadhyay, Jayendra N.; Sarkar, Tapomoy Guha (APS, 2015-03)

We present a mapping of potentially chaotic time-dependent quantum kicked systems to an equivalent approximate effective time-independent scenario, whereby the system is rendered integrable. The time evolution is factorized ...
Floquet analysis of a fractal-spectrum-generating periodically driven quantum system

Bandyopadhyay, Jayendra N.; Sarkar, Tapomoy Guha (APS, 2018-10)

We employ Floquet analysis to study the spectral properties of a double-kicked top (DKT) system. This is a classically nonintegrable dynamical system, which also shows chaos. However, even for the underlying classically ...
Floquet analysis of pulsed Dirac systems: a way to simulate rippled graphene

Sarkar, Tapomoy Guha; Bandyopadhyay, Jayendra N. (Springer, 2015-09)

The low energy continuum limit of graphene is effectively known to be modeled using the Dirac equation in (2 + 1) dimensions. We consider the possibility of using a modulated high frequency periodic driving of a two-dimensional ...
Floquet topological phase transitions in a kicked Haldane-Chern insulator

Bandyopadhyay, Jayendra N.; Sarkar, Tapomoy Guha (APS, 2018-02)

We consider a periodically δ-kicked Haldane type Chern insulator with the kicking applied in the ˆz direction. This is known to behave as an inversion symmetry breaking perturbation, since it introduces a time-dependent ...
Gravitational-wave detection using redshifted 21-cm observations

Sarkar, Tapomoy Guha (APS, 2009-06)

A gravitational-wave traversing the line of sight to a distant source produces a frequency shift which contributes to redshift space distortion. As a consequence, gravitational waves are imprinted as density fluctuations ...
The Imprint of the Baryon Acoustic Oscillations (BAO) in the Cross-correlation of the Redshifted HI 21-cm Signal and the Ly-alpha Forest

Sarkar, Tapomoy Guha (ARXIV, 2011-12)

The cross-correlation of the Ly-alpha forest and redshifted 21-cm emission has recently been proposed as an observational tool for mapping out the large-scale structures in the post-reionization era z < 6. This has a ...
Intensity mapping of post-reionization 21-cm signal and its cross-correlations as a probe of f(R) gravity

Sarkar, Tapomoy Guha (Springer, 2023-01)

We propose the intensity mapping of the redshifted Hi 21-cm signal from the post-reionization epoch as a cosmological probe of f(R) gravity. We consider the Hu–Sawicki family of f(R) gravity models characterized by a single ...
Metric Deformation and Boundary Value Problems in 2D

Sarkar, Tapomoy Guha (OUP, 2012-01)

A new analytical formulation is prescribed to solve the Helmholtz equation in 2D with arbitrary boundary. A suitable diffeomorphism is used to annul the asymmetries in the boundary by mapping it into an equivalent circle. ...

Now showing items 1-20 of 37

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Browsing BITS Faculty Publications by Author "Sarkar, Tapomoy Guha"

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