24 citations · 54 across the 16 of their papers we have counts for
6 papers · 1 filter
Initial clustering of primordial black holes: A general formulation for arbitrary local non-Gaussianity
Hirotaka Ishijima, Teruaki Suyama, Ashu Kushwaha
Initial spatial clustering of primordial black holes (PBHs) induced by local-type non-Gaussianity (LNG) can substantially modify cosmological constraints on PBH abundance. Several…
Gravitational Waves from Primordial Black Holes: Connecting Low-Frequency Scalar-Induced Signatures to High-Frequency Binary Mergers
Ashu Kushwaha
Formation of primordial black holes (PBHs) requires a significant enhancement of curvature perturbations. This enhancement generates a twofold gravitational wave (GW) signature: a…
Secondary Production of Photons from ALP Dark Matter interacting with a Cosmological Magnetic Field
Abdias Aires, Robert Brandenberger, Ashu Kushwaha
Under the assumption that dark matter is a coherently oscillating pseudoscalar field coupled to electromagnetism by the usual Chern-Simons term, we study the production of secondar…
Revisiting Constraints on Primordial Curvature Power Spectrum from PBH Abundances
Ashu Kushwaha, Teruaki Suyama
Primordial black holes (PBHs) can form in the early Universe, during radiation domination, from the collapse of large-amplitude density perturbations shortly after horizon re-entry…
ALP Dark Matter, Cosmological Magnetic Fields and the Direct Collapse Black Hole Formation Scenario
Ashu Kushwaha, Robert Brandenberger
Assuming that dark matter is an ultralight pseudoscalar particle which couples to electromagnetism like an axion (an ALP), we demonstrate that the coupling of the cosmological magn…
An upper limit on cosmological chiral gravitational wave background
Mohammad Ali Gorji, Ashu Kushwaha, Teruaki Suyama
Within the standard framework in which electroweak sphaleron processes relate lepton and baryon number, we derive an upper limit on the amplitude of a chiral gravitational wave bac…