87 citations · 260 across the 16 of their papers we have counts for
16 papers
Inflationary magnetogenesis beyond slow-roll and its induced gravitational waves
Bill Atkins, Debika Chowdhury, Alisha Marriott-Best +1
The origin of magnetic fields observed on both astrophysical and cosmological scales is a compelling problem that has the potential to shed light on the early Universe. We analytic…
Cross-correlation between the curvature perturbations and magnetic fields in pure ultra slow roll inflation
Sagarika Tripathy, Debika Chowdhury, H. V. Ragavendra +1
Motivated by the aim of producing significant number of primordial black holes, over the past few years, there has been a considerable interest in examining models of inflation inv…
Exploring cosmological gravitational wave backgrounds through the synergy of LISA and ET
Alisha Marriott-Best, Debika Chowdhury, Anish Ghoshal +1
The gravitational wave (GW) interferometers LISA and ET are expected to be functional in the next decade(s), possibly around the same time. They will operate over different frequen…
Dark energy, D-branes, and Pulsar Timing Arrays
Debika Chowdhury, Gianmassimo Tasinato, Ivonne Zavala
Several pulsar timing array (PTA) collaborations recently announced the first detection of a stochastic gravitational wave (GW) background, leaving open the question of its source.…
Circumventing the challenges in the choice of the non-conformal coupling function in inflationary magnetogenesis
Sagarika Tripathy, Debika Chowdhury, H. V. Ragavendra +2
[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…
On the response of the Einstein Telescope to Doppler anisotropies
Debika Chowdhury, Gianmassimo Tasinato, Ivonne Zavala
We study the response function of the Einstein Telescope to kinematic Doppler anisotropies, which represent one of the guaranteed properties of the stochastic gravitational wave ba…
On the challenges in the choice of the non-conformal coupling function in inflationary magnetogenesis
Sagarika Tripathy, Debika Chowdhury, Rajeev Kumar Jain +1
Primordial magnetic fields are generated during inflation by considering actions that break the conformal invariance of the electromagnetic field. To break the conformal invariance…
Suppression of scalar power on large scales and associated bispectra
H. V. Ragavendra, Debika Chowdhury, L. Sriramkumar
[Abridged] A sharp cut-off in the primordial scalar power spectrum on large scales has been known to improve the fit to the cosmic microwave background (CMB) data when compared to…
Unique contributions to the scalar bispectrum in `just enough inflation'
H. V. Ragavendra, Debika Chowdhury, L. Sriramkumar
A scalar field rolling down a potential with a large initial velocity results in inflation of a finite duration. Such a scenario suppresses the scalar power on large scales improvi…
Inflation after Planck: Judgment Day
Debika Chowdhury, Jerome Martin, Christophe Ringeval +1
Inflation is considered as the best theory of the early universe by a very large fraction of cosmologists. However, the validity of a scientific model is not decided by counting th…
Enhancing the cross-correlations between magnetic fields and scalar perturbations through parity violation
Debika Chowdhury, L. Sriramkumar, Marc Kamionkowski
One often resorts to a non-minimal coupling of the electromagnetic field in order to generate magnetic fields during inflation. The coupling is expected to depend on a scalar field…
Cross-correlations between scalar perturbations and magnetic fields in bouncing universes
Debika Chowdhury, L. Sriramkumar, Marc Kamionkowski
Bouncing scenarios offer an alternative to the inflationary paradigm for the generation of perturbations in the early universe. Recently, there has been a surge in interest in exam…
Viable tensor-to-scalar ratio in a symmetric matter bounce
Rathul Nath Raveendran, Debika Chowdhury, L. Sriramkumar
Matter bounces refer to scenarios wherein the universe contracts at early times as in a matter dominated epoch until the scale factor reaches a minimum, after which it starts expan…
The scalar-scalar-tensor inflationary three-point function in the axion monodromy model
Debika Chowdhury, V. Sreenath, L. Sriramkumar
The axion monodromy model involves a canonical scalar field that is governed by a linear potential with superimposed modulations. The modulations in the potential are responsible f…
Duality and scale invariant magnetic fields from bouncing universes
Debika Chowdhury, L. Sriramkumar, Rajeev Kumar Jain
Recently, we had numerically shown that, for a non-minimal coupling that is a simple power of the scale factor, scale invariant magnetic fields arise in a class of bouncing univers…
The tensor bi-spectrum in a matter bounce
Debika Chowdhury, V. Sreenath, L. Sriramkumar
Matter bounces are bouncing scenarios wherein the universe contracts as in a matter dominated phase at early times. Such scenarios are known to lead to a scale invariant spectrum o…