Zobrazeno 1 - 10
of 245
pro vyhledávání: '"Sethi, Shiv"'
The first star-forming objects which formed at high redshifts during the cosmic dawn (CD) also emitted photons between Lyman-$\alpha$ and Lyman-limit frequencies. These photons are instrumental in coupling the spin temperature of the neutral hydrogen
Externí odkaz:
http://arxiv.org/abs/2406.16542
Autor:
Chatterjee, Suman, Elahi, Khandakar Md Asif, Bharadwaj, Somnath, Sarkar, Shouvik, Choudhuri, Samir, Sethi, Shiv, Patwa, Akash Kumar
Drift scan observations provide the broad sky coverage and instrumental stability needed to measure the Epoch of Reionization (EoR) 21-cm signal. In such observations, the telescope's pointing center (PC) moves continuously on the sky. The Tracking T
Externí odkaz:
http://arxiv.org/abs/2405.10080
Light mass warm dark matter is an interesting and viable alternative to the cold dark matter paradigm. An intriguing variation of this scenario is the mass-varying dark matter model where the dark matter mass varies with time during its cosmic histor
Externí odkaz:
http://arxiv.org/abs/2405.08476
In recent years, the detection of gravitational waves by LIGO and PTA collaborations have raised the intriguing possibility of excess matter power at small scales. Such an increase can be achieved by ultra slow roll (USR) phase during inflationary ep
Externí odkaz:
http://arxiv.org/abs/2404.00933
Autor:
Sarkar, Anjan K., Sethi, Shiv K.
The presence of massive neutrinos has still not been revealed by the cosmological data. We consider a novel method based on the two-point line-of-sight correlation function of high-resolution Lyman-$\alpha$ data to achieve this end in the paper. We a
Externí odkaz:
http://arxiv.org/abs/2311.18499
[Abridged] In contemporary literature, the calculation of modifications to the inflationary scalar power spectrum due to the loops from the higher order interaction terms in the Hamiltonian have led to a discussion regarding the validity of perturbat
Externí odkaz:
http://arxiv.org/abs/2307.13636
Autor:
Parichha, Abineet, Sethi, Shiv
Publikováno v:
Journal of Cosmology and Astroparticle Physics 11 (2023) 061
The Weakly Interacting Massive Particles(WIMPs) have long been the favored CDM candidate in the standard $\Lambda$CDM model. However, owing to great improvement in the experimental sensitivity in the past decade, some parameter space of the SUSY-base
Externí odkaz:
http://arxiv.org/abs/2305.10315
Nontrivial dark sector physics continues to be an interesting avenue in our quest to the nature of dark matter. In this paper, we study the cosmological signatures of mass-varying dark matter where its mass changes from zero to a nonzero value in the
Externí odkaz:
http://arxiv.org/abs/2303.17947
Autor:
Raghunathan, Agaram, Satish, Keerthipriya, Sathyamurthy, Arasi, Prabu, T., Girish, B. S., Srivani, K. S., Sethi, Shiv K.
The low-frequency radio telescope of the Square Kilometre Array (SKA) is being built by the international radio astronomical community to (i) have orders of magnitude higher sensitivity and (ii) be able to map the sky several hundred times faster, th
Externí odkaz:
http://arxiv.org/abs/2301.06708
Autor:
S., Girish B., S., Harshavardhan Reddy, Sethi, Shiv, S., Srivani K., R., Abhishek, B., Ajithkumar, Bhattramakki, Sahana, Buch, Kaushal, Chaudhuri, Sandeep, Gupta, Yashwant, A., Kamini P., Kudale, Sanjay, S., Madhavi, Muley, Mekhala, T., Prabu, A., Raghunathan, J, Shelton G.
Backed by advances in digital electronics, signal processing, computation, and storage technologies, aperture arrays, which had strongly influenced the design of telescopes in the early years of radio astronomy, have made a comeback. Amid all these d
Externí odkaz:
http://arxiv.org/abs/2301.06707