303 citations · 2k across the 48 of their papers we have counts for
48 papers
Static horizons in cosmology
Ida M. Rasulian, Amjad Ashoorioon
Although previous results have ruled out the possibility of a static event horizon in cosmology, we present black hole and white hole metrics that retain static event horizons whil…
Cosmological perturbation theory with trinity of scalar fields
Amjad Ashoorioon, Shinji Mukohyama, Kazem Rezazadeh +1
We present an explicit formulation of cosmological perturbation theory for three-field models with a flat field space. By performing rotations to align one field with the direction…
Particle motion and accretion disk around rotating accelerating black holes
Amjad Ashoorioon, Mohammad Bagher Jahani Poshteh, Orlando Luongo
We investigate the motion of test particles and the properties of accretion disks around rotating, accelerating black hole spacetimes with non-zero cosmological constants. To do so…
Spherical Collapse Approach for Non-standard Dark Matter Models and Enhanced Early Galaxy Formation in JWST
Zahra Davari, Amjad Ashoorioon, Kazem Rezazadeh
Using the spherical collapse approach, we investigate the impact of two alternative dark matter models, each characterized by distinct non-zero equations of state, one constant and…
Measuring black hole spin through gravitational lensing of pulsars
Amjad Ashoorioon, Mohammad Bagher Jahani Poshteh, Robert B. Mann
We propose a new procedure for measuring the spin of a black hole with an unprecedented accuracy based on the gravitational lensing of millisecond pulsars. We derive the basic equa…
Exorcising the Ghost Condensate Dark Energy with a Sextic Dispersion Relation
A. Ashoorioon, A. Yousefi-Sostani
The universe's current acceleration is a pretty recent phenomenon in cosmological time scales. This means that the modes that have left our horizon since the beginning of the conte…