20 citations · 42 across the 7 of their papers we have counts for
7 papers
A principal-symbol obstruction in metric-affine Gauss--Bonnet gravity
Hamed Bouzari Nezhad
The four-dimensional Riemannian Gauss--Bonnet combination admits more than one continuation to a geometry with an independent affine connection. Two natural candidates, the metric-…
Removing Ostrogradsky modes in multi-field higher-order scalar-tensor theories
Hamed Bouzari Nezhad
We study how the Ostrogradsky modes can be removed in multi-field higher-order scalar-tensor theories. For a general class of theories with an arbitrary number of sca…
Degenerate higher-order scalar-tensor theories in metric-affine gravity
Hamed Bouzari Nezhad
We construct the metric-affine analogue of the quadratic degenerate higher-order scalar-tensor (DHOST) theories. We begin with the metric-affine completion of the quadratic DHOST s…
Scalar fields with derivative coupling to curvature in the Palatini and the metric formulation
Hamed Bouzari Nezhad, Syksy Rasanen
We study models where a scalar field has derivative and non-derivative couplings to the Ricci tensor and the co-Ricci tensor with a view to inflation. We consider both the metric f…
Trans-Planckian Effects in Warm Inflation
H. Bouzari Nezhad, F. Shojai
We study the effect of a non-trivial vacuum prescription on warm inflation observables, namely the power spectrum of the comoving curvature perturbation. Non-trivial choice of vacu…
The Effect of -Vacua on the Scalar and Tensor Spectral Indices: Slow-Roll Approximation
H. Bouzari Nezhad, F. Shojai
Since the duration of inflation is finite, imposing the initial condition in infinite past, i.e. the Bunch-Davies vacuum, is inherently ambiguous. In this paper, we resort to the m…
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…