7 papers
Magnetically assisted primordial scalar perturbations: Scalar-Induced Gravitational Waves
Arko Bhaumik, Theodoros Papanikolaou, Anish Ghoshal
Primordial magnetic fields (PMFs) provide a well-motivated source of cosmological perturbations through their anisotropic stress and may leave observable imprints in both the scala…
Primordial magnetic fields in the light of upcoming post-EoR Lyman- and 21-cm observations
Arko Bhaumik, Sourav Pal, Supratik Pal
The Lorentz force exerted by a primordial magnetic field (PMF) on the coupled baryon-dark matter system may enhance total matter power at small scales after recombination. In the p…
Vector induced Gravitational Waves sourced by Primordial Magnetic Fields
Arko Bhaumik, Theodoros Papanikolaou, Anish Ghoshal
In this work, we develop a generic formalism for the study of tensor perturbations induced at second order by first-order vector metric perturbations, dubbing these induced tensor…
Can spacetime torsion source an extremely red-tilted cosmological GW background?
Arko Bhaumik, Bhaswati Mandal, Soumitra SenGupta
In the presence of spacetime torsion, any generic model of gravity is conformally dual to a scalar-tensor theory augmented with a second rank antisymmetric massless degree o…
Revisiting primordial magnetic fields through 21-cm physics: Bounds and forecasts
Arko Bhaumik, Debarun Paul, Supratik Pal
Primordial magnetic fields (PMFs) may significantly influence 21-cm physics via two mechanisms: (i) magnetic heating of the intergalactic medium (IGM) through ambipolar diffusion (…
Moduli Dynamics in Effective Nested Warped Geometry in Four Dimensions and Some Cosmological Implications
Arko Bhaumik, Soumitra SenGupta
We analyze the effective four-dimensional dynamics of the extra-dimensional moduli fields in curved braneworlds having nested warping, with particular emphasis on the doubly warped…