14 papers
Disformal Maps: Classification and Singular Dynamics
Mohammad Ali Gorji, Pavel Jiroušek, Alexander Vikman +1
Being agnostic about the field content of a gravitational system, we consider a general disformal transformation of the metric, , on a four-dimensional Lore…
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 …
Kinematical correlations via -Poincaré coproducts
Mohammad Ali Gorji, Babak Vakili
We study a kinematical consequence of the Hopf-algebraic momentum composition law in -Minkowski spacetime. The same curved momentum space can be described in different coordina…
Imperfect dark matter with higher derivatives
Mohammad Ali Gorji
We introduce a higher-derivative action for dark matter whose energy-momentum tensor describes an imperfect fluid with nonzero pressure, energy flux, and anisotropic stress. In the…
Covariant scalar-tensor theories beyond second derivatives
Mohammad Ali Gorji, Pavel Petrov, Karim Noui
We propose a covariant, gauge-independent construction of foliation-based scalar-tensor theories, yielding diffeomorphism-invariant operators involving only gradients on the hypers…
Unique gravitational wave signatures of GLPV scalar-tensor theories
Guillem Domènech, Alexander Ganz, Mohammad Ali Gorji +1
We study gravitational waves induced by scalar primordial fluctuations in Gleyzes-Langlois-Piazza-Vernizzi (GLPV), beyond Horndeski, scalar-tensor theories. We uncover, at the leve…