Gravitational waves from metastable cosmic strings in the Pati-Salam model in light of new pulsar timing array data

W Ahmed, TA Chowdhury, S Nasri, S Saad - Physical Review D, 2024 - APS
A series of pulsar timing arrays (PTAs) recently observed gravitational waves at the
nanohertz frequencies. Motivated by this remarkable result, we present a novel class of Pati …

Probing stochastic gravitational wave background from SU (5)× U (1) χ strings in light of NANOGrav 15-year data

W Ahmed, MU Rehman, U Zubair - Journal of Cosmology and …, 2024 - iopscience.iop.org
A realistic model of SU (5)× U (1) χ, embedded in SO (10) supersymmetric grand unified
theory, is investigated for the emergence of a metastable cosmic string network. This …

-hybrid inflation, gravitino dark matter, and stochastic gravitational wave background from cosmic strings

A Afzal, W Ahmed, MU Rehman, Q Shafi - Physical Review D, 2022 - APS
We present a successful realization of supersymmetric μ-hybrid inflation model based on a
gauged U (1) B–L extension of the minimal supersymmetric standard model, with the soft …

Radiative symmetry breaking, cosmic strings and observable gravity waves in 𝖴 (1) 𝖱 symmetric 𝖲𝖴 (5)× 𝖴 (1) χ

W Ahmed, U Zubair - Journal of Cosmology and Astroparticle …, 2023 - iopscience.iop.org
We implement shifted hybrid inflation in the framework of supersymmetric SU (5)× U (1) χ
GUT model which provides a natural solution to the monopole problem appearing in the …

Seeking de-Sitter Vacua in the String Landscape

GK Leontaris, P Shukla - arXiv preprint arXiv:2303.16689, 2023 - arxiv.org
In this report, we present a concise review on the various moduli stabilisation schemes
proposed in the context of type IIB superstring compactifications using Calabi-Yau …

Observable r, gravitino dark matter, and non-thermal leptogenesis in no-scale supergravity

W Ahmed, M Moosa, S Munir, U Zubair - Journal of High Energy Physics, 2023 - Springer
A bstract We analyse the shifted hybrid inflation in a no-scale supersymmetric SU (5) GUT
model which naturally circumvents the monopole problem. The no-scale framework is …

Primordial monopoles, black holes and gravitational waves

A Moursy, Q Shafi - arXiv preprint arXiv:2405.04397, 2024 - arxiv.org
We show how topologically stable superheavy magnetic monopoles and primordial black
holes can be generated at observable levels by the waterfall field in hybrid inflation models …

Gravitational wave production after inflation for a hybrid inflationary model

R Thomas, J Thomas, SP Surendran, M Joy - arXiv preprint arXiv …, 2023 - arxiv.org
We discuss a cosmological scenario with a stochastic background of gravitational waves
sourced by the tensor perturbation due to a hybrid inflationary model with cubic potential …