67 citations · 441 across the 22 of their papers we have counts for
22 papers
Spectrum of gravitational waves from long-lasting primordial sources
Sabir Ramazanov
We discuss long-lasting gravitational wave sources arising and operating during radiation-dominated stage. Under a set of assumptions, we establish the correspondence between cosmo…
Shimmering gravitons in the gamma-ray sky
Sabir Ramazanov, Rome Samanta, Georg Trenkler +1
What is the highest energy at which gravitons can be observed? We address this question by studying graviton-to-photon conversion - the inverse-Gertsenshtein effect - in the magnet…
Heating up Peccei-Quinn scale
Sabir Ramazanov, Rome Samanta
We discuss production of QCD axion dark matter in a novel scenario, which assumes time-varying scale of Peccei-Quinn symmetry breaking. The latter decreases as the Universe's tempe…
Shrouded black holes in Einstein-Gauss-Bonnet gravity
Eugeny Babichev, William T. Emond, Sabir Ramazanov
We study black holes in a modified gravity scenario involving a scalar field quadratically coupled to the Gauss-Bonnet invariant. The scalar is assumed to be in a spontaneously bro…
Gravitational waves from melting cosmic strings
William T. Emond, Sabir Ramazanov, Rome Samanta
Appearance of cosmic strings in the early Universe is a common manifestation of new physics typically linked to some high energy scale. In this paper, we discuss a different situat…
Observing primordial magnetic fields through Dark Matter
Sabir Ramazanov, Federico R. Urban, Alexander Vikman
Primordial magnetic fields are often thought to be the early Universe seeds that have bloomed into what we observe today as galactic and extra-galactic magnetic fields. Owing to th…