39 citations · 83 across the 7 of their papers we have counts for
7 papers
Trans-Planckian Effect in Cosmology
S. Cheraghchi, F. Shojai, M. H. Abbassi
Apart from the assumption that the inflation started at an infinite time in the past, the more realistic initial state of the quantum fluctuations is described by a mixed quantum s…
Birkhoff Theorem for Berwald Finsler spacetimes
Nicoleta Voicu, Christian Pfeifer, Samira Cheraghchi
Finsler spacetime geometry is a canonical extension of Riemannian spacetime geometry. It is based on a general length measure for curves (which does not necessarily arise from a sp…
Running vacuum in QFT in FLRW spacetime: The dynamics of from the quantized matter fields
Cristian Moreno-Pulido, Joan Sola Peracaula, Samira Cheraghchi
Phenomenological work in the last few years has provided significant support to the idea that the vacuum energy density (VED) is a running quantity with the cosmological evolution…
Four-dimensional SO(3)-spherically symmetric Berwald Finsler spaces
Samira Cheraghchi, Christian Pfeifer, Nicoleta Voicu
We locally classify all SO(3)-invariant 4-dimensional pseudo-Finsler Berwald structures. These are Finslerian geometries which are closest to (spatially, or SO(3))-spherically symm…
Super-horizon effects on the gauge invariant effective energy density in f(R) gravity
S. Cheraghchi, F. Shojai
In this article we study the gauge invariant effective energy momentum tensor for cosmological perturbations in f(R) gravity during the inflationary epoch. Considering the super-ho…
On the initial conditions of scalar and tensor fluctuations in gravity
S. Cheraghchi, F. Shojai
We have considered the perturbation equations governing the growth of fluctuations in generalized scalar tensor theory during inflation. we have found that the scalar metric pertur…
On the gravitational instability in the Newtonian limit of MOG
Fatimah Shojai, Samira Cheraghchi, Hamed Bouzari Nezhad
We have found some analytical cosmological solutions to MOdified Gravity (MOG). These solutions describe different evolutionary epochs of an isotropic and homogeneous universe. Dur…