arXiv subjects

Abhijit Let

Publications and source records attributed to Abhijit Let.

3 recordsLinked to original sources

arXiv2024

Tachyonic effects on K\"ahler moduli stabilized inflaton potential in type-IIB/F theory

We investigate the effects of inclusion of charged tachyonic open-string scalars in the perturbative and the non-perturbative K\"ahler moduli stabilizations in a geometry of three intersecting magnetized D7-brane stacks in type-IIB/F theory and also study the overall influence of this process on the inflaton potential, in a hybrid inflation scenario. We find that a tachyon lowers the minimum of the inflaton potential and assists to end the inflation. For simplicity, we have included one tachyon at a time in the present work and observe that this procedure preserves the features of slow-roll plateau of the potential. An interesting observation here is that the tachyonic part of the potential can be fine-tuned to get an almost zero minimum of the potential, thereby conforming to the small experimental value of the cosmological constant

hep-ph↗

arXiv2023

Non-perturbative stabilization of two K\"ahler moduli in type-IIB/F theory and the inflaton potential

We consider a combination of perturbative and non-perturbative corrections in K\"ahler moduli stabilizations in the configuration of three magnetised intersecting D7 branes in the type-IIB/F theory, compactified on the 6d T^6/Z_N orbifold of Calabi-Yau three-fold (CY_3). Two of the K\"ahler moduli are stabilized non-perturbatively, out of the three which get perturbative corrections up to one-loop-order multi-graviton scattering amplitudes in the large volume scenario. In this framework, the dS vacua are achieved through all K\"ahler moduli stabilizations by considering the D-term. We obtain inflaton potentials of slow-roll plateau-type, which are expected by recent cosmological observations. Calculations of cosmological parameters with the potentials yield experimentally favoured values.

gr-qc↗

arXiv2022

Single field slow-roll effective potential from K\"ahler moduli stabilizations in type IIB/F-theory

We derive a single field slow-roll inflaton potential in three intersecting $D7$ branes configuration under type IIB/F-theory compactification. Among three resulting K\"{a}hler moduli corresponding to three orthogonal directions, two are stabilized via perturbative corrections in K\"{a}hler potential arising from large volume scenario ($\alpha'^3$) and four graviton scattering amplitude upto one loop level and the remaining K\"{a}hler modulus is stabilized by KKLT-type non-perturbative correction in superpotential. The symmetric combination of two canonically normalized and perturbatively stabilized K\"{a}hler moduli gives the inflaton field and the anti-symmetric combination manifests as an auxiliary field.

hep-th↗