Zobrazeno 1 - 10
of 164
pro vyhledávání: '"JAIN, RAJEEV KUMAR"'
In the current era of precision cosmology, the persistence of cosmological tensions, most notably the Hubble tension and the $S_8$ tension, challenges the standard $\Lambda$CDM model. To reconcile these tensions via late-time modifications to expansi
Externí odkaz:
http://arxiv.org/abs/2412.00931
Autor:
Kushwaha, Ashu, Jain, Rajeev Kumar
While photons and gravitons do not interact significantly, photons can be converted to gravitons in a background magnetic field -- a phenomenon known as the Gertsenshtein effect. In this paper, we investigate whether chiral electromagnetic (EM) waves
Externí odkaz:
http://arxiv.org/abs/2410.07338
Publikováno v:
JHEP 10 (2024) 142
Ultra-low mass primordial black holes (PBH), briefly dominating the expansion of the universe, would leave detectable imprints in the secondary stochastic gravitational wave background (SGWB). Such a scenario leads to a characteristic doubly peaked s
Externí odkaz:
http://arxiv.org/abs/2409.04436
Autor:
Bagui, Eleni, Clesse, Sebastien, De Luca, Valerio, Ezquiaga, Jose María, Franciolini, Gabriele, García-Bellido, Juan, Joana, Cristian, Jain, Rajeev Kumar, Kuroyanagi, Sachiko, Musco, Ilia, Papanikolaou, Theodoros, Raccanelli, Alvise, Renaux-Petel, Sébastien, Riotto, Antonio, Morales, Ester Ruiz, Scalisi, Marco, Sergijenko, Olga, Unal, Caner, Vennin, Vincent, Wands, David
In the recent years, primordial black holes (PBHs) have emerged as one of the most interesting and hotly debated topics in cosmology. Among other possibilities, PBHs could explain both some of the signals from binary black hole mergers observed in gr
Externí odkaz:
http://arxiv.org/abs/2310.19857
Publikováno v:
Phys. Rev. D 108, 123532 (2023)
Pulsar Timing Array collaborations have recently announced the discovery of a stochastic gravitational wave background (SGWB) at nanohertz frequencies. We analyze the GW signals from the domination of ultra-low mass primordial black holes (PBHs) in t
Externí odkaz:
http://arxiv.org/abs/2308.07912
Autor:
Sai, P. Jishnu, Jain, Rajeev Kumar
Publikováno v:
JCAP 09 (2023) 043
Light spectator fields may not be dynamically relevant for the inflationary phase of the early universe, but they can still induce interesting imprints on cosmological observables. In this paper, we compute the cross-correlations of the inflationary
Externí odkaz:
http://arxiv.org/abs/2307.07502
Publikováno v:
Published in Journal of Cosmology and Astroparticle Physics \textbf{02}, 034 (2024)
We explore the role of dissipative effects during warm inflation leading to the small-scale enhancement of the power spectrum of curvature perturbations. In this paper, we specifically focus on non-canonical warm inflationary scenarios and study a mo
Externí odkaz:
http://arxiv.org/abs/2302.08940
The Hubble tension refers to the discrepancy in the value of the Hubble constant $H_0$ inferred from the cosmic microwave background observations, assuming the concordance $\Lambda$CDM model of the Universe, and that from the distance ladder and othe
Externí odkaz:
http://arxiv.org/abs/2301.09382
Publikováno v:
JHEP 05 (2023) 169
Ultra-low mass primordial black holes (PBH), which may briefly dominate the energy density of the universe but completely evaporate before the big bang nucleosynthesis (BBN), can lead to interesting observable signatures. In our previous work, we stu
Externí odkaz:
http://arxiv.org/abs/2212.00775
Autor:
Tripathy, Sagarika, Chowdhury, Debika, Ragavendra, H. V., Jain, Rajeev Kumar, Sriramkumar, L.
[Abridged] As is well known, in order to generate magnetic fields of observed amplitudes during inflation, the conformal invariance of the electromagnetic field has to be broken by coupling it either to the inflaton or to the scalar curvature. Coupli
Externí odkaz:
http://arxiv.org/abs/2211.05834