7 papers
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…
Cosmological bounds on dark matter annihilation using dark ages 21-cm signal
Vivekanand Mohapatra
We investigate the impact of dark matter (DM) annihilation on the global 21-cm signal during the dark ages and cosmic dawn eras. The 21-cm line provides a complementary probe for s…
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…
Axion-Photon Conversion In Magnetized Universe: Impact On The Global 21-cm Signal
Pravin Kumar Natwariya, Vivekanand Mohapatra, Hriditi Howlader
The reported anomalous global 21-cm signal from the cosmic dawn era by Experiment to Detect the Global Epoch of Reionisation Signature (EDGES) could hint towards new phy…
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…