84 citations · 293 across the 23 of their papers we have counts for
23 papers
Infrared Lines from Sterile-Neutrino Transition Magnetic Moments at JWST
Hriditi Howlader, Alekha C. Nayak, Tripurari Srivastava
We investigate infrared line signatures from radiatively decaying sterile-neutrino dark matter using publicly available JWST/NIRSpec IFU blank-sky observations. The main signal con…
Dark ages bounds on nonaccreting massive compact halo objects
Vivekanand Mohapatra, Alekha C. Nayak
We derive a complementary cosmological upper bound on the fraction of dark matter residing inside non-accreting massive compact halo objects (MACHOs) using the cosmic dawn and dark…
Constraining Primordial Black Holes via p-wave annihilation in light of CMB Spectral Distortion and 21-cm global signal
Shibsankar Si, Pravin Kumar Natwariya, Alekha C. Nayak
Primordial black holes (PBHs) can form spike density halos through the accretion of weakly interacting massive particles (WIMPs). In these halos, the enhanced density significantly…
Constraining self-interacting ultrahigh-energy muon neutrinos by cosmic microwave background spectral distortion
Pravin Kumar Natwariya, Shibsankar Si, Alekha C. Nayak +1
The neutrino telescopes have firmly established the existence of ultrahigh-energy neutrinos. Observations of these neutrinos offer a unique probe of neutrino self-interactions. Thi…
Revisiting constraints on superconducting cosmic strings in light of Dark Ages global 21-cm signal
Shibsankar Si, Vivekanand Mohapatra, Pravin kumar Natwariya +1
The Superconducting Cosmic Strings (SCS) are a special case of cosmic strings that have a core carrying a charged field. When SCS passes through magnetized regions, the charged par…
Bounds on decaying sterile neutrinos via magnetic dipole moment from COB intensity
Hriditi Howlader, Vivekanand Mohapatra, Alekha C. Nayak +1
A recent observation by Long Range Reconnaissance Imager (LORRI) mounted on NASA's New Horizons yielded the most accurate measurement of the cosmic optical background (COB). The re…
Geometric optics analysis in Lorentz violating Chern-Simons electrodynamics
Arpan Das, Hriditi Howlader, Alekha C. Nayak
We study the geometric optics limit of the electrodynamics in the presence of Lorentz violating Chern-Simons term in (3+1) dimensions. The Chern-Simons term couples the dual electr…
Constraining Viscous Dark Matter in light of CMB Spectral Distortion
Shibsankar Si, Alekha C. Nayak, Pravin Kumar Natwariya
We calculate the - and \textit{y}-type spectral distortions of Cosmic Microwave Background (CMB), taking a non-standard interaction between baryons and viscous dark matter. Usin…
Primordial Magnetic Fields in Light of Dark Ages Global 21-cm Signal
Vivekanand Mohapatra, Pravin Kumar Natwariya, Alekha C. Nayak
We study the constraints on primordial magnetic fields (PMFs) in light of the global 21-cm signal observed during the dark ages. Primordial magnetic fields can heat the intergalact…
In Search of Global 21-cm Signal using Artificial Neural Network in light of ARCADE 2
Vivekanand Mohapatra, Johnny J, Pravin Kumar Natwariya +2
Understanding the astrophysical nature of the first stars remains an unsolved problem in cosmology. The redshifted global 21-cm signal acts as a treasure trove to prob…
Bounds on sterile neutrino lifetime and mixing angle with active neutrinos by global 21 cm signal
Pravin Kumar Natwariya, Alekha C. Nayak
Sterile neutrinos can be a possible candidate for dark matter. Sterile neutrinos are radiatively unstable and can inject photon energy into the intergalactic medium (IGM). The inje…
Constraining spinning primordial black holes with global 21-cm signal
Pravin Kumar Natwariya, Alekha C. Nayak, Tripurari Srivastava
We study the upper projected bounds on the dark matter fraction in the form of the primordial black holes (PBHs) with a non-zero spin by using the absorption feature in the global…
Dark matter admixed neutron star properties in the light of gravitational wave observations: a two fluid approach
Arpan Das, Tuhin Malik, Alekha C. Nayak
We consider the effect of density dependent dark matter on the neutron star mass, radius, and tidal deformability. Nuclear matter (normal matter) as well as the fermionic dark matt…
Baryon-Dark matter interaction in presence of magnetic fields in light of EDGES signal
Jitesh R. Bhatt, Pravin Kumar Natwariya, Alekha C. Nayak +1
We have shown that in presence of a cosmic magnetic field the bounds on baryon dark matter cross-section (), dark-matter mass () and values of the magnetic field ($B_0…
Viscous dark matter and 21 cm cosmology
Jitesh R. Bhatt, Arvind Kumar Mishra, Alekha C. Nayak
The EDGES experiment has detected the global absorption signal of 21 cm line at in cosmic dawn era and reported its amplitude larger than the standard cosmological predic…
Very special relativity induced phase in neutrino oscillation
Alekha C. Nayak
In Very Special Relativity (VSR), the neutrino mass term is coupled with the VSR preferred axis, and hence Lorentz violating in nature. Beyond standard model physics predicts neutr…
Confronting nuclear equation of state in the presence of dark matter using GW170817 observation in relativistic mean field theory approach
Arpan Das, Tuhin Malik, Alekha C. Nayak
We confront admixture of dark matter inside neutron star using gravitational wave constraints coming from binary neutron star merger. We consider a relativistic mean field model in…
Cosmological Dark Matter in a Conformal Model
Prasenjit Sanyal, Alekha C. Nayak, Gopal Kashyap +1
We study the collider, astrophysical and cosmological constraints on the dark matter sector of a conformal model within the framework of both the freeze out as well as the freeze i…
Phenomenological Implications of Very Special Relativity
Alekha C. Nayak, Pankaj Jain
We discuss several phenomenological implications of Very Special Relativity (VSR). It is assumed that there is a small violation of Lorentz invariance and the true symmetry group o…
Vector dark matter annihilation with internal bremsstrahlung
Gulab Bambhaniya, Jason Kumar, Danny Marfatia +2
We consider scenarios in which the annihilation of self-conjugate spin-1 dark matter to a Standard Model fermion-antifermion final state is chirality suppressed, but where this sup…
Effect of VSR invariant Chern-Simon Lagrangian on photon polarization
A. C. Nayak, R. K. Verma, P. Jain
We propose a generalization of the Chern-Simon (CS) Lagrangian which is invariant under the SIM(2) transformations but not under the full Lorentz group. We study the effect of such…
Elko and mass dimension one field of spin one half: causality and Fermi statistics
Dharam Vir Ahluwalia, Alekha Chandra Nayak
We review how Elko arise as an extension of complex valued four-component Majorana spinors. This is followed by a discussion that constrains certain elements of phase freedom. A pr…
ELKO fermions as dark matter candidates
Bakul Agarwal, Pankaj Jain, Subhadip Mitra +2
We study the implications of the ELKO fermions as a cold dark matter candidate. Such fermions arise in theories that are not symmetric under the full Lorentz group. Although they d…