相关论文: Characteristics of Effective Dark Matter in Nonloc…
We consider f(R,T) modified theory of gravity, in which the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar and the trace of the energy-momentum tensor of the matter, in order to investigate the dark-matter…
Dark matter has been introduced to explain many independent gravitational effects at different astronomical scales, in galaxies, groups of galaxies, clusters, superclusters and even across the full horizon. This review describes the…
Exotic dark matter together with dark energy or cosmological constant seem to dominate in the Universe. An even higher density of such matter seems to be gravitationally trapped in our Galaxy. The nature of dark matter can be unveiled only,…
Observations show that the expansion of the Universe is accelerating. This requires that the dominant constituent of matter in the Universe has some unusual properties like negative pressure. This exotic component has been given the name…
It is already known that a simple nonlocal de Sitter gravity model, which we denote as $\sqrt{dS}$ gravity, contains an exact vacuum cosmological solution which mimics dark energy and dark matter and is in very good agreement with the…
This work refines arguments forbidding non-linear dynamical gravity from appearing in the low energy effective description of field theories with local kinematics, even for those with instantaneous long-range interactions. Specifically, we…
Despite many nice properties and numerous achievements, general relativity is not a complete theory. One of actual approaches towards more complete theory of gravity is its nonlocal modification. We present here a brief review of nonlocal…
The discovery of cosmic acceleration has triggered a consistent body of theoretical work aimed at modeling its phenomenology and understanding its fundamental physical nature. In recent years, a powerful formalism that accomplishes both…
This work wants to show how standard General Relativity (GR) is able to explain galactic rotation curves without the need for dark matter, this starting from the idea that when Einstein's equations are applied to the dynamics of a galaxy…
The nonlinear affine Goldstone model of the emergent gravity, built on the nonlinearly realized/hidden affine symmetry, is concisely revisited. Beyond General Relativity, the explicit violation of general invariance/relativity, under…
The huge amounts of undetected and exotic dark matter and dark energy needed to make general relativity work on large scales argue that we should investigate modifications of gravity. The only stable, metric-based and invariant alternative…
We construct a quadratic curvature theory of gravity whose graviton propagator around the Minkowski background respects wordline inversion symmetry, the particle approximation to modular invariance in string theory. This symmetry…
This paper explores the generalized ghost dark energy model in the framework of $f(\textsl{Q}, \textsl{L}_{m})$ gravity, where $\textsl{Q}$ represents the non-metricity scalar and $\textsl{L}_{m}$ denotes the matter-Lagrangian density. We…
We report the detection of dark energy near the Milky Way made with precision observations of the local Hubble flow of expansion. We estimate the local density of dark energy and find that it is near, if not exactly equal to, the global…
The accelerating expansion of universe can be described by the non-zero cosmological constant or the dark energy. However, the origin of the dark energy remains a mystery of modern physics. The local Lorentz invariance is the most exact…
Einstein's theory of gravity admits a low energy effective quantum field description from which predictions beyond classical general relativity can be drawn. As gravitational wave detectors improve, one may ask whether non-classical…
We discuss a class of (local and non-local) theories of gravity that share same properties: i) they admit the Einstein spacetime with arbitrary cosmological constant as a solution; ii) the on-shell action of such a theory vanishes and iii)…
Assuming the validity of the general relativistic description of gravitation on astrophysical and cosmological length scales, we analytically infer that the Friedmann-Robertson-Walker cosmology with Einsteinian cosmological constant, and a…
We describe a general constitutive framework for a teleparallel extension of the general theory of relativity. This approach goes beyond the teleparallel equivalent of general relativity (TEGR) by broadening the analogy with the…
Many cosmological observations call for the existence of dark matter. The most direct evidence for dark matter is inferred from the measured flatness of galactic rotation curves. The latter is based on Newtonian gravity. Alternative…