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Bhopal, India

Dutta P.,IISER Bhopal
Monthly Notices of the Royal Astronomical Society: Letters | Year: 2016

Here we introduce moments of visibility function and discuss howthose can be used to estimate the power spectrum of the turbulent velocity of external spiral galaxies. We perform numerical simulation to confirm the credibility of this method and found that for galaxies with lower inclination angles it works fine. The estimator outlined here is unbiased and has the potential to recover the turbulent velocity spectrum completely from radio interferometric observations. © 2015 The Authors. Source

Dutta P.,IISER Bhopal
Monthly Notices of the Royal Astronomical Society | Year: 2015

We use numerical simulations to investigate effect of turbulent velocity on the power spectrum of HI intensity from external galaxies when (a) all emission is considered, (b) emission with velocity range smaller than the turbulent velocity dispersion is considered. We found that for case (a) the intensity fluctuation depends directly only on the power spectrum of the column density, whereas for case (b) it depends only on the turbulent velocity fluctuation. We discuss the implications of this result in real observations of HI fluctuations. © 2015 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society. Source

Dutta K.,Saha Institute of Nuclear Physics | Panda S.,IISER Bhopal | Patel A.,IISER Bhopal
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

Although f(R) modification of late-time cosmology is successful in explaining the present cosmic acceleration, it is difficult to simultaneously satisfy the fifth-force constraint. Even when the fifth-force constraint is satisfied, the effective scalar degree of freedom may move to a point, close to its potential minimum, in the field space where the Ricci scalar diverges. We elucidate this point further with a specific example of f(R) gravity that incorporates several viable f(R) gravity models from the literature. In particular, we show that the nonlinear evolution of the scalar field in pressureless contracting dust can easily lead to the curvature singularity, making this theory unviable. © 2015 American Physical Society. Source

Goswami S.,IISER Bhopal | Jena H.S.,IISER Bhopal | Konar S.,IISER Bhopal
Inorganic Chemistry | Year: 2014

We present here a simple, milder, and environmentally benign heterogeneous catalytic method for the transformation of tetrazines to oxadiazole derivatives at room temperature (25 °C) using our earlier synthesized iron-squarate based 3D metal organic framework, [Fe3(OH)3(C 4O4)(C4O4)0.5] n (FeSq-MOF). © 2014 American Chemical Society. Source

Sanda S.,IISER Bhopal | Parshamoni S.,IISER Bhopal | Konar S.,IISER Bhopal
Inorganic Chemistry | Year: 2013

A new 2D interdigitated and highly flexible, breathing metal-organic framework has been synthesized through a diffusion technique by using the aldrithiol linker and pyromellitate ligand. The compound shows selective, stepwise, reversible, and hysteretic adsorption properties for CO2 gas and H2O, MeOH, and CH3CN vapors. © 2013 American Chemical Society. Source

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