Charged scalar-tensor solitons and black holes with (approximate) Anti-de Sitter asymptotics
Sign Up to like & getrecommendations! Published in 2019 at "Journal of High Energy Physics"
DOI: 10.1007/jhep01(2019)142
Abstract: A bstractWe discuss charged and static solutions in a shift-symmetric scalar-tensor gravity model including a negative cosmological constant. The solutions are only approximately Anti-de Sitter (AdS) asymptotically. While spherically symmetric black holes with scalar-tensor hair… read more here.
Keywords: black holes; scalar tensor; anti sitter; tensor solitons ... See more keywords
Stable wormholes in scalar-tensor theories
Sign Up to like & getrecommendations! Published in 2019 at "Journal of High Energy Physics"
DOI: 10.1007/jhep01(2019)221
Abstract: A bstractWe reconsider the issue of whether scalar-tensor theories can admit stable wormhole configurations supported by a non-trivial radial profile for the scalar field. Using a recently proposed effective theory for perturbations around static, spherically… read more here.
Keywords: stable wormholes; scalar tensor; tensor theories; wormholes scalar ... See more keywords
Higher dimensional Bianchi type-III string cosmological models with dark energy in Brans-Dicke scalar-tensor theory of gravitation
Sign Up to like & getrecommendations! Published in 2021 at "New Astronomy"
DOI: 10.1016/j.newast.2021.101658
Abstract: Abstract The Five dimensional anisotropic Bianchi type-III cosmological model has been investigated within the framework of Brans-Dicke (Phys. Rev. 124:925, 1961) scalar-tensor theory of gravitation. Dark Energy fluid and cosmic strings are considered as a… read more here.
Keywords: bianchi type; scalar tensor; model; energy ... See more keywords
Exact cosmological black hole solutions in scalar tensor vector gravity
Sign Up to like & getrecommendations! Published in 2019 at "Classical and Quantum Gravity"
DOI: 10.1088/1361-6382/ab55c8
Abstract: We find an exact solution of Scalar-Tensor-Vector Gravity field equations that represents a black hole embedded in an expanding universe. This is the first solution of the kind found in the theory. We analyze the… read more here.
Keywords: scalar tensor; gravity; vector gravity; black hole ... See more keywords
Constraints on scalar and tensor spectra from Neff
Sign Up to like & getrecommendations! Published in 2019 at "Journal of Cosmology and Astroparticle Physics"
DOI: 10.1088/1475-7516/2019/06/007
Abstract: At the linear level, the gravitational wave (GW) spectrum predicted by inflation, and many of its alternatives, can have arbitrarily small amplitude and consequently an unconstrained tilt. However, at second order, tensor fluctuations are sourced… read more here.
Keywords: tensor; tensor spectra; spectrum; scalar spectrum ... See more keywords
Constraining scalar-tensor modified gravity with gravitational waves and large scale structure surveys
Sign Up to like & getrecommendations! Published in 2020 at "Journal of Cosmology and Astroparticle Physics"
DOI: 10.1088/1475-7516/2021/01/068
Abstract: The first multi-messenger gravitational wave event has had a transformative effect on the space of modified gravity models. In this paper we study the enhanced tests of gravity that are possible with a future set… read more here.
Keywords: large scale; gravitational waves; modified gravity; scalar tensor ... See more keywords
Scalar and tensor perturbations in DHOST bounce cosmology
Sign Up to like & getrecommendations! Published in 2021 at "Journal of Cosmology and Astroparticle Physics"
DOI: 10.1088/1475-7516/2021/11/045
Abstract: We investigate the bounce realization in the framework of DHOST cosmology, focusing on the relation with observables. We perform a detailed analysis of the scalar and tensor perturbations during the Ekpyrotic contraction phase, the bounce… read more here.
Keywords: phase; tensor perturbations; cosmology; scalar tensor ... See more keywords
Phantom scalar-tensor models and cosmological tensions
Sign Up to like & getrecommendations! Published in 2023 at "Journal of Cosmology and Astroparticle Physics"
DOI: 10.1088/1475-7516/2023/04/029
Abstract: We study three different extended scalar-tensor theories of gravity by also allowing a negative sign for the kinetic term for the scalar field in the Jordan frame. Our scope is to understand how the observational… read more here.
Keywords: scalar tensor; term; sign kinetic; kinetic term ... See more keywords
Investigating scalar-tensor-gravity with statistics of the cosmic large-scale structure
Sign Up to like & getrecommendations! Published in 2018 at "Monthly Notices of the Royal Astronomical Society"
DOI: 10.1093/mnras/sty2919
Abstract: Future observations of the large-scale structure have the potential to investigate cosmological models with a high degree of complexity, including the properties of gravity on large scales, the presence of a complicated dark energy component,… read more here.
Keywords: gravity; large scale; scalar tensor; scale structure ... See more keywords
Black hole accretion in scalar–tensor–vector gravity
Sign Up to like & getrecommendations! Published in 2019 at "Monthly Notices of the Royal Astronomical Society"
DOI: 10.1093/mnras/stz2889
Abstract: We examine the accretion of matter on to a black hole in scalar–tensor–vector gravity (STVG) also known as modified gravity (MOG). The gravitational constant is G = GN(1 + α) where α is a parameter taken… read more here.
Keywords: tensor vector; black hole; accretion; hole ... See more keywords
Numerical studies on core collapse supernova in self-interacting massive scalar-tensor gravity
Sign Up to like & getrecommendations! Published in 2019 at "Physical Review D"
DOI: 10.1103/physrevd.100.024027
Abstract: We investigate stellar core collapse in scalar-tensor theory with a massive self-interacting scalar field. In these theories, strong long-lived inverse chirp signals could be induced during the stellar core collapse, which provides us with several… read more here.
Keywords: core collapse; scalar tensor; self interacting; self ... See more keywords