Reheating predictions in gravity theories with derivative coupling
Sign Up to like & getrecommendations! Published in 2017 at "Journal of Cosmology and Astroparticle Physics"
DOI: 10.1088/1475-7516/2017/02/027
Abstract: We investigate the inflationary predictions of a simple Horndeski theory where the inflaton scalar field has a non-minimal derivative coupling (NMDC) to the Einstein tensor. The NMDC is very motivated for the construction of successful… read more here.
Keywords: theories derivative; derivative coupling; gravity theories; predictions gravity ... See more keywords
Acceleration relations in the Milky Way as differentiators of modified gravity theories
Sign Up to like & getrecommendations! Published in 2020 at "Physical Review D"
DOI: 10.1103/physrevd.101.084015
Abstract: The dynamical mass of galaxies and the Newtonian acceleration generated from the baryons have been found to be strongly correlated. This correlation is known as 'Mass-Discrepancy Acceleration Relation' (MDAR). Further investigations have revealed a tighter… read more here.
Keywords: gravity theories; modified gravity; gravity; relation ... See more keywords
Enigmatic velocity dispersions of ultradiffuse galaxies in light of modified gravity theories and the radial acceleration relation
Sign Up to like & getrecommendations! Published in 2020 at "Physical Review D"
DOI: 10.1103/physrevd.102.024068
Abstract: Recent observations of anomalous line-of-sight velocity dispersions of two ultra-diffuse galaxies (UDGs) provide a stringent test for modified gravity theories. While NGC 1052-DF2 exhibits an extremely low dispersion value ($\sigma \sim 7.8_{-2.2}^{+5.6}$ km/s), the reported… read more here.
Keywords: gravity theories; modified gravity; velocity dispersions; gravity ... See more keywords
Conserved charge of a gravity theory with $p$-form gauge fields and its property under Kaluza-Klein reduction
Sign Up to like & getrecommendations! Published in 2017 at "Physical Review D"
DOI: 10.1103/physrevd.95.104022
Abstract: In this paper, we investigate the conserved charges of generally diffeomorphism invariant gravity theories with a wide variety of matter fields, particularly of the theories with multiple scalar fields and $p$-form potentials, in the context… read more here.
Keywords: shell; form; kaluza klein; gravity theories ... See more keywords
Removing the Ostrogradski ghost from degenerate gravity theories
Sign Up to like & getrecommendations! Published in 2017 at "Physical Review D"
DOI: 10.1103/physrevd.96.044035
Abstract: The Ostrogradski ghost problem that appears in higher derivative system is considered for systems with constraints. A prescription for removal of the ghost creating momenta is described based on the Dirac's constraint analysis. It is… read more here.
Keywords: ghost; ostrogradski ghost; removing ostrogradski; ghost degenerate ... See more keywords