4 papers
Primordial black holes and scalar-induced gravitational waves in the supersymmetric 331 model from SU(6)
Imtiaz Khan, Niamat Ullah, Ali Muhammad +4
We study primordial black holes and scalar-induced gravitational waves in the supersymmetric 331 model based on SU(6). The inflaton continues to be the D-flat radial combination of…
Finite-duration non-slow-roll effects in inflationary production of ultralight vector dark matter
Imtiaz Khan, Niamat Ullah, Chengxun Yuan +3
Inflationary production of ultralight vector dark matter can be amplified by a brief non-slow-roll phase, yet instantaneous mass transitions generate ultraviolet ringing and leave…
Conformal dark matter and MHz gravitational waves
Imtiaz Khan, Niamat Ullah, Salvatore Capozziello +2
A localized enhancement of the primordial curvature spectrum can leave two distinct relics: gravitationally produced conformal-fermion dark matter and a scalar-induced stochastic g…
Parametric Resonance of Higgsed Vector Dark Matter: Inflationary Initial Conditions and Sourced Displacements
Imtiaz Khan, Salvatore Capozziello, G. Mustafa +2
Parametric resonance in a Higgsed Abelian sector provides an efficient mechanism for producing vector dark matter, but its viability depends crucially on the origin of the initial…