80 citations · 190 across the 12 of their papers we have counts for
12 papers
Trispectrum in Extended USR Model with Transition to SR
Hassan Firouzjahi, Amin Nassiri-Rad
We study the trispectrum in a two-phase USR-SR setup of inflation in which the USR stage is extended in the initial phase of inflation while the second stage of inflation proceeds…
Stochastic Inflation with Interacting Noises
Amin Nassiri-Rad, Haidar Sheikhahmadi, Hassan Firouzjahi
Stochastic formalism is a powerful tool to calculate the cosmological correlators non-perturbatively. However, it requires the initial data for the amplitude of the noise on t…
RG-Flow Renormalized One-Loop Corrections to the Power Spectrum in USR Inflation
Haidar Sheikhahmadi, Amin Nassiri-Rad
The nature of one-loop corrections to long-wavelength CMB-scale modes in single-field inflation models with an intermediate ultra-slow-roll (USR) phase remains a subject of active…
Induced Gravitational Waves from Non-attractor Inflation and NANOGrav data
Amin Nassiri-Rad, Kosar Asadi
In this paper, we investigate the scalar-induced gravitational waves in single-field non-attractor inflation for the Pulsar Timing Arrays data. Our model comprises three phases of…
Stochastic Multiple Fields Inflation: Diffusion Dominated Regime
Kosar Asadi, Amin Nassiri-Rad, Hassan Firouzjahi
We study multiple fields inflation in diffusion dominated regime using stochastic formalism. The fields are under pure Brownian motion in a dS background with boundaries in hi…
Inflation with Stochastic Boundary
Amin Nassiri-Rad, Kosar Asadi, Hassan Firouzjahi
We study the Brownian motion of a field where there are boundaries in the inflationary field space. Both the field and the boundary undergo Brownian motions with the amplitudes of…
Stochastic Effects in Axion Inflation and Primordial Black Holes Formation
Alireza Talebian, Amin Nassiri-Rad, Hassan Firouzjahi
We revisit the model of axion inflation in the context of stochastic inflation and investigate the effects of the stochastic noises associated to the electromagnetic fields. Becaus…
Primordial Helical Magnetic Fields from Inflation?
Alireza Talebian, Amin Nassiri-Rad, Hassan Firouzjahi
We revisit the mechanism of helical magnetogenesis during inflation with a parity violating interaction using the formalism of stochastic inflation. One of the polarization of the…
Stochastic non-attractor inflation
Hassan Firouzjahi, Amin Nassiri-Rad, Mahdiyar Noorbala
We extend the formalism of stochastic inflation to the setup of non-attractor inflation with a sound speed . We obtain the Langevin equations for the superhorizon perturbation…
Revisiting Magnetogenesis during Inflation
Alireza Talebian, Amin Nassiri-Rad, Hassan Firouzjahi
We revisit the mechanism of primordial magnetogenesis during inflation by taking into account the dynamics of the stochastic noises of the electromagnetic perturbations. We obtain…
Stochastic Effects in Anisotropic Inflation
Alireza Talebian, Amin Nassiri-Rad, Hassan Firouzjahi
We revisit the stochastic effects in the model of anisotropic inflation containing a gauge field. We obtain the Langevin equations for the inflaton and gauge fields perturba…
Stochastic Ultra Slow Roll Inflation
Hassan Firouzjahi, Amin Nassiri-Rad, Mahdiyar Noorbala
We study the ultra slow roll model in the context of stochastic inflation. Using stochastic formalism, we calculate the mean number of -folds, the power spectrum, the bispe…