93 citations · 359 across the 27 of their papers we have counts for
25 papers · 1 filter
Minkowski Functionals of CII Line Intensity Maps: Probing Astrophysics and Primordial Features
Sandeep Kumar Acharya, Pravabati Chingangbam
Line intensity mapping aims to measure the total cumulative light of spectral lines from galaxies, without resolving individual sources. In this work, we investigate mock intensity…
Probing inflationary features with galaxy ultraviolet luminosity function observables
Sandeep Kumar Acharya
We use the galaxy ultraviolet luminosity function measurements at to constrain modification to standard inflationary power spectrum. These observables are sensitive to the…
Utilizing localized fast radio bursts to constrain their progenitors and the expansion history of the Universe
Sandeep Kumar Acharya, Paz Beniamini
Fast radio bursts (FRBs) are increasingly being used for cosmological applications such as measuring the Hubble constant and baryon abundance. The increasing number of localized FR…
Redshift dependence of FRB host dispersion measures across cosmic epochs
Sandeep Kumar Acharya, Paz Beniamini
We constrain the redshift dependence of (rest frame) host galaxy dispersion measures of localized Fast Radio Bursts (FRBs) by assuming it to vary as a simple power law ($\propto (1…
Soft Photon Heating: A Semi-Analytic Framework and Applications to cm Cosmology
Bryce Cyr, Sandeep Kumar Acharya, Jens Chluba
The presence of an abundant population of low frequency photons at high redshifts (such as a radio background) can source leading order effects on the evolution of the matter and s…
Sunyaev-Zeldovich signatures from non-thermal, relativistic electrons using CMB maps
Sandeep Kumar Acharya
Relativistically energetic, non-thermal population of electrons can give rise to unique CMB spectral distortion signatures which can be significantly different from thermal Sunyaev…
Disentangling the primordial nature of stochastic gravitational wave backgrounds with CMB spectral distortions
Bryce Cyr, Thomas Kite, Jens Chluba +5
The recent detection of a stochastic gravitational wave background (SGWB) at nanohertz frequencies by pulsar timing arrays (PTAs) has sparked a flurry of interest. Beyond the stand…
Constraining broad photon spectrum injections from exotic and astrophysical sources
Sandeep Kumar Acharya, Bryce Cyr, Jens Chluba
We study the evolution of photon injections with a power-law type spectrum inserted at various epochs of the universe, and obtain constraints on their parameter space from multiple…
A cosmic string solution to the radio synchrotron background
Bryce Cyr, Jens Chluba, Sandeep Kumar Acharya
We investigate the low-frequency spectral emission from a network of superconducting cosmic string loops in hopes of explaining the observed radio synchrotron background. After con…
Constraints on the spectral signatures of superconducting cosmic strings
Bryce Cyr, Jens Chluba, Sandeep Kumar Acharya
If they exist, networks of superconducting cosmic strings are capable of injecting copious amounts of electromagnetic energy into the background over a broad range of frequencies.…
The role of soft photon injection and heating in 21 cm cosmology
Sandeep Kumar Acharya, Bryce Cyr, Jens Chluba
The ARCADE radio excess and EDGES measurement remain puzzling. A link between the two has been previously considered, however, in this work we highlight an important related effect…
A closer look at dark photon explanations of the excess radio background
Sandeep Kumar Acharya, Jens Chluba
The observed excess radio background has remained a puzzle for over a decade. A recent new physics solution involves dark matter that decays into dark photons in the presence of a…
Can accreting primordial black holes explain the excess radio background?
Sandeep Kumar Acharya, Jiten Dhandha, Jens Chluba
The excess radio background seen at has stimulated much scientific debate in the past years. Recently, it was pointed out that the soft photon emission f…
Revisiting secondary CMB distortions due to kinetic Sunyaev-Zel'dovich effect from quasar bubbles before reionization
Sandeep Kumar Acharya, Subhabrata Majumdar
We discuss the secondary cosmic microwave background (CMB) anisotropy due to kinetic Sunyaev-Zel'dovich (kSZ) effect from ionized bubbles around individual quasars prior to the rei…
Importance of intracluster scattering and relativistic corrections from tSZ effect with Cosmic Infrared Background
Sandeep Kumar Acharya, Jens Chluba
The Sunyaev-Zeldovich effect towards clusters of galaxies has become a standard probe of cosmology. It is caused by the scattering of photons from the cosmic microwave background (…
The non-thermal secondary CMB anisotropies from a cosmic distribution of radio galaxy lobes
Sandeep Kumar Acharya, Subhabrata Majumdar, Biman B. Nath
Current and upcoming high angular resolution and multi-frequency experiments are well poised to explore the rich landscape of secondary CMB anisotropies. In this context, we comput…
CMB spectral distortions from continuous large energy release
Sandeep Kumar Acharya, Jens Chluba
Accurate computations of spectral distortions of the cosmic microwave background (CMB) are required for constraining energy release scenarios at redshifts . The exis…
Comparison of numerical methods for computing the repeated Compton scattering of photons in isotropic media
Sandeep Kumar Acharya, Jens Chluba, Abir Sarkar
Repeated Compton scattering of photons with thermal electrons is one of the fundamental processes at work in many astrophysical plasma. Solving the exact evolution equations is har…
Constraints on of high energy non-thermal neutrino injections upto from CMB spectral distortions and abundance of light elements
Sandeep Kumar Acharya, Rishi Khatri
High energy neutrinos and anti-neutrinos ( 100 GeV) can inject energetic electromagnetic particles into the baryon-photon plasma in the high redshift universe through elec…
Thermalization of large energy release in the early Universe
Jens Chluba, Andrea Ravenni, Sandeep Kumar Acharya
Spectral distortions of the cosmic microwave background (CMB) provide a unique tool for learning about the early phases of cosmic history, reaching deep into the primordial Univers…
CMB and BBN constraints on evaporating primordial black holes revisited
Sandeep Kumar Acharya, Rishi Khatri
We derive new CMB anisotropy power spectrum and BBN constraints for evaporating primordial black holes by explicitly solving the electromagnetic particle cascades of emitted partic…
CMB spectral distortions constraints on primordial black holes, cosmic strings and long lived unstable particles revisited
Sandeep Kumar Acharya, Rishi Khatri
We calculate the spectral distortions from Hawking evaporation of primordial black holes before the epoch of recombination, taking into account emission of all standard model parti…
CMB anisotropy and BBN constraints on pre-recombination decay of dark matter to visible particles
Sandeep Kumar Acharya, Rishi Khatri
Injection of high energy electromagnetic particles around the recombination epoch can modify the standard recombination history and therefore the CMB anisotropy power spectrum. Pre…
New CMB spectral distortion constraints on decaying dark matter with full evolution of electromagnetic cascades before recombination
Sandeep Kumar Acharya, Rishi Khatri
Current constraints on energy injection in the form of energetic particles before the epoch of recombination using CMB spectral distortions assume that all energy goes into and…