156 citations · 1.1k across the 74 of their papers we have counts for
76 papers
Black Hole Shadows and Quasinormal Modes with Dark Matter at the Horizon
Armin Sadeghi, Javad T. Firouzjaee, Saeed Fakhry
In this work, we study the effect of a surrounding dark matter halo on two horizon-scale observables of a black hole: its shadow and quasinormal-mode spectrum. We consider a Schwar…
Detectability of 21-cm Power Spectra from the Epoch of Reionization using Modern Radio Telescopes
Ali Bagheri Koochaksaraei, Lily Mobahat, Sara Gholamhosseinian +1
One of the unsolved questions in astrophysics and cosmology is the development of a robust physical model to explain the thermal history of the intergalactic medium during the epoc…
Primordial black hole in Lorentz-violating theories: Insights from Bumblebee gravity
Mohsen Khodadi, Javad T. Firouzjaee
The Bumblebee gravity (BG) model, featuring spontaneous Lorentz symmetry breaking via a vector field non-minimally coupled to curvature, has been widely used to explore Lorentz-vio…
Fragility of stealth solutions in mimetic gravity
Alireza Allahyari, Clarisse Donio, Mohammad Ali Gorji +2
We study a broad class of constrained mimetic-type extensions of general relativity with action , where i…
When Dark Energy Turns On: Constraints on a Critical Emergence Model
Mahdi Najafi, Mahdi Habibollahi, Masoume Reyhani +4
We investigate a specific emergent dark energy scenario, known as critically emergent dark energy (CEDE), in which dark energy is effectively absent in the early Universe and becom…
A Multi-Probe ISW Study of Dark Energy Models with Negative Energy Density: Galaxy Correlations, Lensing Bispectrum, and Planck ISW-Lensing Likelihood
Payam Ghafari, Mahdi Najafi, Mina Ghodsi Yengejeh +3
We investigate the late-time imprints of three dark energy (DE) models, namely, the Chevallier-Polarski-Linder (CPL) parametrization, CDM, and an Omnipotent DE model, on…
Confronting dark energy in Harada's Conformal Killing Gravity with observational data
Mohsen Khodadi, Gaetano Lambiase, Javad. T. Firouzjaee
Based on a comprehensive analysis of recent observational data-a combination of DESI DR1, Planck CMB, and Pantheon+ SN Ia-this study critically evaluates the two dark energy (DE) p…
Cosmological Inflation in Gravity
Maryam Shiravand, Saeed Fakhry, Javad T. Firouzjaee +1
Cosmological inflation provides the standard description of the early accelerated expansion of the Universe, but the shortcomings of General Relativity (GR) motivate the search for…
Primordial observables of explicit diffeomorphism violation in gravity
Mohsen Khodadi, Nils A. Nilsson, Gaetano Lambiase +1
We investigate the potential for current and future gravitational-wave detectors to observe imprints of explicit diffeomorphism violation in primordial signals. Starting from a sim…
Quantum Dynamics and Information Measures in PT and Anti-PT-Symmetric Systems
Amir Ahmadi, Roozbeh H. Asgari, Javad T. Firouzjaee
In this study, we investigate qubit dynamics under PT and Anti-PT-symmetric non-Hermitian Hamiltonians, focusing on phase evolution, decoherence, quantum speed limits (QSL), and Ré…
High-redshift Galaxies from JWST Observations in More Realistic Dark Matter Halo Models
Saeed Fakhry, Reyhaneh Vojoudi Salmani, Javad T. Firouzjaee
The James Webb Space Telescope (JWST) has unveiled unexpectedly massive galaxy candidates at high redshifts, challenging standard CDM cosmological predictions. In this work, we…
Mapping Crisis-Driven Market Dynamics: A Transfer Entropy and Kramers-Moyal Approach to Financial Networks
Pouriya Khalilian, Amirhossein N. Golestani, Mohammad Eslamifar +2
Financial markets are dynamic, interconnected systems where local shocks can trigger widespread instability, challenging portfolio managers and policymakers. Traditional correlatio…
Toward Gravitational Lensing in Modified Theories of Gravity
Ali Tizfahm, Saeed Fakhry, Javad T. Firouzjaee +1
In this study, we investigate gravitational lensing within modified gravity frameworks, focusing on the Hu-Sawicki and normal branch Dvali-Gabadadze-Porrati (nDGP) models, a…
A note on the stability of the Cauchy horizon in regular black holes without mass inflation
Mohsen Khodadi, Javad T. Firouzjaee
Unlike generic models of regular black holes (BHs) with nonzero surface gravity on both Cauchy and event horizons, an inner-degenerate counterpart with zero Cauchy horizon surface…
Event Horizon Telescope observations exclude compact objects in baseline mimetic gravity
Mohsen Khodadi, Sunny Vagnozzi, Javad T. Firouzjaee
Mimetic gravity has gained significant appeal in cosmological contexts, but static spherically symmetric space-times within the baseline theory are highly non-trivial: the two natu…
Dynamical dark energy confronted with multiple CMB missions
Mahdi Najafi, Supriya Pan, Eleonora Di Valentino +1
The measurements of the cosmic microwave background (CMB) have played a significant role in understanding the nature of dark energy. In this article, we investigate the dynamics of…
Robust Preference for Dynamical Dark Energy in DESI BAO and SN Measurements
William Giarè, Mahdi Najafi, Supriya Pan +2
Recent Baryon Acoustic Oscillation (BAO) measurements released by DESI, when combined with Cosmic Microwave Background (CMB) data from Planck and two different samples of Type Ia s…
Gravitational Lensing in More Realistic Dark Matter Halo Models
Ali Tizfahm, Saeed Fakhry, Javad T. Firouzjaee +1
In this study, we explore gravitational lensing using more realistic dark matter halo models, moving beyond the limitations of spherical-collapse approximations. Through analytical…
Accretion Efficiency Evolution of Central Supermassive Black Holes in Quasars
Arta Khosravi, Alireza Karamzadeh, Seyed Sajad Tabasi +1
The ongoing debate regarding the most accurate accretion model for supermassive black holes at the center of quasars has remained a contentious issue in astrophysics. One significa…
Structure Formation in Various Dynamical Dark Energy Scenarios
Masoume Reyhani, Mahdi Najafi, Javad T. Firouzjaee +1
This research investigates the impact of the nature of Dark Energy (DE) on structure formation, focusing on the matter power spectrum and the Integrated Sachs-Wolfe effect (ISW). B…
Cosmological LTB Black Hole in a Quintom Universe
Sareh Eslamzadeh, Kourosh Nozari, J. T. Firouzjaee
We study cosmological Lemaitre-Tolman-Bondi (LTB) black hole thermodynamics immersed in a quintom universe. We investigate some thermodynamic aspects of such a black hole in detail…
SVR Algorithm as a Tool for More Optimal Intergalactic Medium Simulation in the Epoch of Reionization
Mahsa Berahman, Seyed Sajad Tabasi, Javad T. Firouzjaee +1
All kinds of simulations of the intergalactic medium, such as hydrodynamic simulation, N-body simulation, numerical and semi-numerical simulation, etc., have been used to realize t…
A New Constraint on the Simulation of the Intergalactic Medium through the Evolution of the Neutral Hydrogen Fraction in the Epoch of Reionization
S. Mobina Hosseini, Bahareh Soleimanpour Salmasi, Seyed Sajad Tabasi +1
The thermal history of the intergalactic medium is full of extremely useful data in the field of astrophysics and cosmology. In other words, by examining this environment in differ…
Compact Binary Merger Rate in Dark-Matter Spikes
Saeed Fakhry, Zahra Salehnia, Azin Shirmohammadi +2
Nowadays, the existence of supermassive black holes (SMBHs) in the center of galactic halos is almost confirmed. An extremely dense region referred to as dark-matter spike is expec…