1k citations · 1.3k across the 28 of their papers we have counts for
28 papers
Machian Gravity: A mathematical formulation for Mach's Principle
Santanu Das
The general theory of relativity (GR) was proposed with an aim of incorporating Mach's principle mathematically. Despite early hopes, it became evident that GR did not follow Mach'…
Aspects of Everpresent (I): A Fluctuating Cosmological Constant from Spacetime Discreteness
Santanu Das, Arad Nasiri, Yasaman K. Yazdi
We provide a comprehensive discussion of the Everpresent cosmological model arising from fundamental principles in causal set theory and unimodular gravity. In this framework t…
AlgoSCR: An algorithm for Solar Contamination Removal from radio interferometric data
Anh Phan, Santanu Das, Albert Stebbins +10
Hydrogen intensity mapping is a new field in astronomy that promises to make three-dimensional maps of the matter distribution of the Universe using the redshifted $21\,\textrm{cm}…
Dynamics of a randomly kicked particle
Santanu Das, Anupam Kundu
Levy walk (LW) process has been used as a simple model for describing anomalous diffusion in which the mean squared displacement of the walker grows non-linearly with time in contr…
Brownian motion under intermittent harmonic potentials
Ion Santra, Santanu Das, Sujit Kumar Nath
We study the effects of an intermittent harmonic potential of strength -- that switches on and off stochastically at a constant rate , on an overdamped Brownian parti…
Beam Measurements of the Tianlai Dish Radio Telescope using an Unmanned Aerial Vehicle
Juyong Zhang, Jingxin Liu, Fengquan Wu +7
Precision measurement of the beam pattern of an antenna is very important for many applications. While traditionally such measurement is often made in a microwave anechoic chamber…
Cosmic Microwave Background Anisotropy numerical solution (CMBAns) I: An introduction to calculation
Santanu Das, Anh Phan
Cosmological Boltzmann codes are often used by researchers for calculating the CMB angular power spectra from different theoretical models, for cosmological parameter estimation, e…
SI Toolbox - Full documentation
Santanu Das
SI Toolbox is a package for estimating the isotropy violation in the CMB sky. It can be used for estimating the BipoSH coefficients, Dipole modulation, and Doppler boost parameters…
Joint Bayesian analysis of large angular scale CMB temperature anomalies
Shabbir Shaikh, Suvodip Mukherjee, Santanu Das +2
Cosmic microwave background measurements show an agreement with the concordance cosmology model except for a few notable anomalies: Power Suppression, the lack of large scale power…
SIToolBox : A package for Bayesian estimation of the isotropy violation in the CMB sky
Santanu Das
The standard model of cosmology predicts a statistically isotropic (SI) CMB sky. However, the SI violation signals are always present in an observed sky-map. Different cosmological…
Progress in the Construction and Testing of the Tianlai Radio Interferometers
Santanu Das, Christopher J. Anderson, Reza Ansari +44
The Tianlai Pathfinder is designed to demonstrate the feasibility of using a wide field of view radio interferometers to map the density of neutral hydrogen in the Universe after t…
Effective Mass in Bose-Einstein Condensation in the Bound State and Phonon Propagation in the Unbound States
Asis. K. Bandyopadhyay, Atrayee Bhattacharya, Kamal Choudhary +1
The dark and bright solitons in different systems are already known in Klein-Gordon lattice. Instead of an external driving force, if the intrinsic field is only considered, then t…
Non-Linear Modes in Lithium Niobate Ferroelectrics with niobium antisite defects
Atrayee Bhattacharya, Kamal Choudhary, Santanu Das +2
Ferroelectric belongs to an important class of materials showing very interesting nonlinear optical properties that have a variety of application in photonic devices In a discrete…
Estimating SI violation in CMB due to non-circular beam and complex scan in minutes
Nidhi Pant, Santanu Das, Aditya Rotti +2
Mild, unavoidable deviations from circular-symmetry of instrumental beams along with scan strategy can give rise to measurable Statistical Isotropy (SI) violation in Cosmic Microwa…
Bayesian inference on the sphere beyond statistical isotropy
Santanu Das, Benjamin D. Wandelt, Tarun Souradeep
We present a general method for Bayesian inference of the underlying covariance structure of random fields on a sphere. We employ the Bipolar Spherical Harmonic (BipoSH) representa…
Effect of noncircularity of experimental beam on CMB parameter estimation
Santanu Das, Sanjit Mitra, Sonu Tabitha Paulson
Measurement of Cosmic Microwave Background (CMB) anisotropies has been playing a lead role in precision cosmology by providing some of the tightest constrains on cosmological model…
Estimation of Inflation parameters for Perturbed Power Law model using recent CMB measurements
Suvodip Mukherjee, Santanu Das, Minu Joy +1
Cosmic Microwave Background (CMB) is an important probe for understanding the inflationary era of the Universe. We consider the Perturbed Power Law (PPL) model of inflation which i…
Revised cosmological parameters after BICEP 2 and BOSS
Santanu Das, Suvodip Mukherjee, Tarun Souradeep
Estimation of parameters of the \lq standard\rq \,model of cosmology have dramatically improved over past few decades due to increasingly exquisite measurements made by Cosmic Micr…
SCoPE: An efficient method of Cosmological Parameter Estimation
Santanu Das, Tarun Souradeep
Markov Chain Monte Carlo (MCMC) sampler is widely used for cosmological parameter estimation from CMB and other data. However, due to the intrinsic serial nature of the MCMC sample…
Statistical isotropy violation in WMAP CMB maps resulting from non-circular beams
Santanu Das, Sanjit Mitra, Aditya Rotti +2
Statistical isotropy (SI) of Cosmic Microwave Background (CMB) fluctuations is a key observational test to validate the cosmological principle underlying the standard model of cosm…
Suppressing CMB low multipoles with ISW effect
Santanu Das, Tarun Souradeep
Recent results of Planck data reveal that the power in the low multipoles of the CMB angular power spectrum, approximately up to , is significantly lower than the theoretical…
Leakage of power from dipole to higher multipoles due to non-symmetric WMAP beam
Santanu Das, Tarun Souradeep
A number of studies of WMAP and Planck claimed the low multipole (specially quadrupole) power deficiency in CMB power spectrum. Anomaly in the orientations of the low multipoles ha…
Revealing Non-circular beam effect in WMAP-7 CMB maps with BipoSH measures of Statistical Isotropy
Nidhi Joshi, Santanu Das, Aditya Rotti +2
Mild, unavoidable deviations from circular-symmetry of instrumental beams in current Cosmic Microwave Background (CMB) experiments now pose a significant challenge to deriving high…
Dipole leakage and low CMB multipoles
Santanu Das, Tarun Souradeep
A number of studies of WMAP-7 have highlighted that the power at the low multipoles in CMB power spectrum are lower than their theoretically predicted values. Angular correlation b…