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pro vyhledávání: '"Mishra, Swagat S."'
One of the key predictions of the standard inflationary paradigm is the quantum mechanical generation of the transverse and traceless tensor fluctuations due to the rapid accelerated expansion of space, which later constitute a stochastic background
Externí odkaz:
http://arxiv.org/abs/2407.07956
We investigate the formation and decay of oscillons during the post-inflationary reheating epoch from inflaton oscillations around asymptotically flat potentials $V(\varphi)$ in the presence of an external coupling of the form $\frac{1}{2}\, g^2 \, \
Externí odkaz:
http://arxiv.org/abs/2406.00108
Autor:
Mishra, Swagat S.
These lecture notes provide a pedagogical introduction to some aspects of the inflationary cosmology, including the background scalar field dynamics, generation of primordial seed perturbations via quantum fluctuations during inflation, and the proce
Externí odkaz:
http://arxiv.org/abs/2403.10606
Autor:
Mishra, Swagat S., Sahni, Varun
We introduce a new class of hilltop and plateau potentials which can successfully unify inflation and dark energy resulting in Quintessential Inflation (QI). Interestingly these new potentials are related through an inverse transformation. Namely, if
Externí odkaz:
http://arxiv.org/abs/2402.04316
Primordial Black Holes (PBHs) may form in the early Universe, from the gravitational collapse of large density perturbations, generated by large quantum fluctuations during inflation. Since PBHs form from rare over-densities, their abundance is sensi
Externí odkaz:
http://arxiv.org/abs/2303.17375
Autor:
Mahbub, Rafid, Mishra, Swagat S.
We investigate the possibility of oscillon formation during the preheating phase of asymmetric inflationary potentials. We analytically establish the existence of oscillon-like solutions for the Klein-Gordon equation for a polynomial potential of the
Externí odkaz:
http://arxiv.org/abs/2303.07503
Numerical simulations of the inflationary dynamics are presented here for a single canonical scalar field minimally coupled to gravity. We spell out the basic equations governing the inflationary dynamics in terms of cosmic time $t$ and define a set
Externí odkaz:
http://arxiv.org/abs/2212.00529
We show that a large class of modified gravity theories (MOG) with the Jordan-frame Lagrangian $f(R)$ translate into scalar-field (scalaron) models with hilltop potentials in the Einstein frame. (A rare exception to this rule is provided by the Staro
Externí odkaz:
http://arxiv.org/abs/2210.01828
Autor:
Mishra, Swagat S., Sahni, Varun
We discuss implications of the latest BICEP/Keck data release for inflationary models, with particular emphasis on scalar fields with non-canonical Lagrangians of the type ${\cal L} = X^\alpha - V(\phi)$. The observational upper bound on the tensor-t
Externí odkaz:
http://arxiv.org/abs/2202.03467
It is well known that the inflationary scenario often displays different sets of degeneracies in its predictions for CMB observables. These degeneracies usually arise either because multiple inflationary models predict similar values for the scalar s
Externí odkaz:
http://arxiv.org/abs/2101.00271