8 papers
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…
Dark ages bounds on non-accreting massive compact halo objects
Vivekanand Mohapatra, Alekha C. Nayak
We derive a complementary cosmological upper bound on the fraction of dark matter residing inside massive compact halo objects (MACHOs) using the cosmic dawn and dark ages global 2…
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…
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…
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…