Journal ArticleDOI
Second-order scalar-tensor field equations in a four-dimensional space
TLDR
In this article, the second-order Euler-Lagrange tensors are derived from a Lagrangian which is at most of second order in the derivatives of the field functions.Abstract:
Lagrange scalar densities which are concomitants of a pseudo-Riemannian metric-tensor, a scalar field and their derivatives of arbitrary order are considered. The most general second-order Euler-Lagrange tensors derivable from such a Lagrangian in a four-dimensional space are constructed, and it is shown that these Euler-Lagrange tensors may be obtained from a Lagrangian which is at most of second order in the derivatives of the field functions.read more
Citations
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Compact objects in Horndeski gravity
TL;DR: A review of the progress made so far in the study of compact objects (black holes and neutron stars) within Horndeski gravity can be found in this paper, where the authors also present some new results on slowly rotating neutron stars.
Journal ArticleDOI
Forecasts on the speed of gravitational waves at high z
TL;DR: In this article, the authors consider the possibility of running the Planck mass corrections on modified GW propagation and parametrize both corrections in terms of an effective GW luminosity distance and perform a forecast analysis using standard siren events from BNS mergers, within the sensitivity predicted for the ET and DECIGO.
Journal ArticleDOI
An accurate perturbative approach to redshift space clustering of biased tracers in modified gravity
TL;DR: In this paper, the scale-dependent Gaussian Streaming Model (GSM) is used to predict the anisotropic redshift-space correlation function for biased tracers in modified gravity models.
Journal ArticleDOI
Thermodynamics of scalar–tensor theory with non-minimally derivative coupling
TL;DR: In this paper, it was shown that the first law on the apparent horizon is equivalent to the Friedmann equation for the scalar-tensor theory with non-minimally derivative coupling.
Journal ArticleDOI
On the stability conditions for theories of modified gravity in presence of matter fields
TL;DR: In this paper, a thorough stability analysis of modified gravity theories in the presence of matter fields is presented, where the authors use the Effective Field Theory framework for dark energy and modified gravity to retain a general approach for the gravity sector and a Sorkin-Schutz action for the matter one.
References
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Journal ArticleDOI
Mach's principle and a relativistic theory of gravitation
Carl H. Brans,R. H. Dicke +1 more
TL;DR: In this paper, the role of Mach's principle in physics is discussed in relation to the equivalence principle and the difficulties encountered in attempting to incorporate Mach's principles into general relativity are discussed.
Journal ArticleDOI
The Einstein Tensor and Its Generalizations
TL;DR: In this paper, the number of independent tensors of this type depends crucially on the dimension of the space, and, in the four dimensional case, the only tensors with these properties are the metric and the Einstein tensors.
Journal ArticleDOI
Comments on the scalar-tensor theory
TL;DR: In this article, the ponderomotive laws of a scalar-tensor theory are constructed free of approximations in the form of integral laws, and the integrals are extended over two-and three-dimensional domains that lie entirely in empty space but surround the regions containing matter.
Journal ArticleDOI
The uniqueness of the einstein field equations in a four-dimensional space.
TL;DR: In this article, the Euler-Lagrange equations corresponding to a Lagrange density which is a function of g ≥ 2 and its first two derivatives are investigated and necessary and sufficient conditions for these equations to be of second order are obtained and it is shown that in a four-dimensional space the Einstein field equations (with cosmological term) are the only permissible second order Euler Lagrange equations.
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