arXiv subjects

N. Malsawmtluangi

Publications and source records attributed to N. Malsawmtluangi.

7 recordsLinked to original sources

arXiv2022

$e^+e^-$ annihilation on the stochastic background of primordial gravitational waves with BKP18

The evolution of inflationary primordial gravitational waves with the expansion of the universe is studied while taking into account the $e^+e^-$ annihilation which leads to step correction in the spectrum of primordial gravitational waves which is $\sim 10\%$ in the amplitude and $\sim 25\%$ in the energy density. The amplitudes and energy densities are studied for the $α$-attractor inflation models which are in agreement with the recent BICEP/Keck and Planck 2018 joint result. The energy densities are well within the big bang nucleosynthesis bound, but the spectra for these models are very much below the detection range of the currently operating and upcoming detectors.

gr-qc↗

arXiv2022

Oscillatory amplitude of stochastic gravitational wave spectrum

Primordial gravitational waves generated from early universe are placed in the squeezed vacuum state and the resulting stochastic background is studied for various models of the expanding universe. The quantum effect on the stochastic gravitational waves leads to overall enhancement of the amplitude and spectral energy density when compared to those in the absence of squeezing effect with continued increase in the amplitude in the accelerating stage and oscillatory behavior at higher frequency range of the spectrum in the accelerating universe. Through the quantum effect, it is also found that the reheating phenomenon affects the entire spectrum. The results of the present study may be useful to test the possibility of detection of the stochastic gravitational waves by current and future gravitational wave detectors and whether these waves exist in the squeezed vacuum state.

gr-qc↗

arXiv2021

BB mode angular power spectrum of CMB from massive gravity

The BB-mode correlation angular power spectrum of CMB is studied for primordial massive gravitational waves for several inflation models. The comparative study of the angular power spectrum with the joint BICEP2/Keck Array and Planck data suggests further constraint on the lower and upper bounds on the mass of primordial gravitons. Assuming a modified dispersion relation, the mass of primordial graviton is also calculated. The resulting constraint also agrees with other theoretical estimates.

gr-qc↗

arXiv2021

Analytical study of classic models of Hybrid Inflation

We study the classic hybrid inflation model in its original and modified forms and show the shape of the inflationary potentials and analyze the amount of primordial gravitational waves each model predicts. We compare the resulting EE-mode and BB-mode power spectrum with the data from the joint BICEP2/Keck and Planck collaboration to check the viability of each model.

gr-qc↗

arXiv2017

BB mode spectrum of CMB and Inflation

Quantum effect on the BB-mode correlation spectrum of Cosmic Microwave Background for several inflation models is studied with the BICEP2/Keck Array and Planck joint data. The results do not rule out either single or multi field models of slow-roll inflation. The quantum effect is found more prominent for the inflation models with larger values of tensor-to-scalar ratio and smaller values of tensor spectral index.

gr-qc↗

arXiv2017

Graviton mass constraint from CMB

The effect of primordial massive gravitational waves on the BB-mode correlation angular power spectrum of CMB is studied for several inflation models. The angular power spectrum with the BICEP2/Keck Array and Planck joint data suggests further constraint on the lower and upper bounds on the mass of primordial gravitons

gr-qc↗

arXiv2015

Slow roll inflation and BB mode angular power spectrum of CMB

The BB-mode angular correlation power spectrum of CMB is obtained by considering the primordial gravitational waves in the squeezed vacuum state for various inflationary models and results are compared with the joint analysis of the BICEP2/Keck Array and Planck 353 GHz data. The present results may constrain several models of inflation.

astro-ph.CO↗