相关论文: A stealth defect of spacetime
A new class of spacetime defect solutions of Einstein Field equations of Edelen's direct Poincar\'{e} Gauge Field theory without biaxial symmetry is presented. The interior solution describes a core of defects where curvature vanishes and…
Based on the dual principle in super-luminous Lorentz transformation this work shows that pseudo-spin of a time-like bradyon appears to space-like observers as iso-spin of a corresponding tachyon. Due to the weak interaction, lepton-tachyon…
What is the nature - continuous or discrete - of matter and of its fundamental interactions? The physical meaning, the properties and the consequences of a discrete scalar field are discussed; limits for the validity of a mathematical…
We look for cosmologies with a scalar field (dark energy without cosmological constant), which mimic the standard $\Lambda CDM$ cosmological model yielding exactly the same large-scale geometry described by the evolution of the Hubble…
We study the feebly interacting dark matter with the Standard Model fields, where the preceding and the latter ones are the constituents of the bosonic cosmological objects, the scalar boson stars (BS). The scalar dark matter (SDM) massive…
We construct a generic class of models for complex scalar fields -- minimally coupled to gravity and electromagnetism -- with the property that their energy-momentum tensor and the electric current vanish for certain massive configurations.…
A novel idea is proposed for a natural solution of the dark energy and its cosmic coincidence problem. The existence of local antigravity sources, associated with astrophysical matter configurations distributed throughout the universe, can…
A unified treatment of mass varying dark matter coupled to cosmon-{\em like} dark energy is shown to result in {\em effective} generalized Chaplygin gas (GCG) scenarios. The mass varying mechanism is treated as a cosmon field inherent…
A class of dynamical dark energy models is constructed through an extended version of fermion fields corresponding to phantom dark ghost spinors, which are spin one half with mass dimension one. We find that if these spinors interact with…
The weak field approximation in a model of de Sitter gravity is investigated in the static and spherically symmetric case, under the assumption that the vacuum spacetime without perturbations from matter fields is a torsion-free de Sitter…
A toy model giving rise to long lived super heavy particles and an small vacuum density energy, of the order of the one measured in the present universe, is constructed. This model consists in hidden sector invariant under an $SU(2)_L$…
We study the coincidence problem of late cosmic acceleration by assuming that the present ratio between dark matter and dark energy is a slowly varying function of the scale factor. As dark energy component we consider two different…
We propose a new model of scalar field dark matter interacting with dark energy. Adopting a fluid description of the dark matter field in the regime of rapid oscillations, we find that the equation of state for dark matter is non-zero and…
A nontrivial scalar field configuration of vanishing energy-momentum is reported. These matter configurations have no influence on the metric and therefore they are not be "detected" gravitationally. This phenomenon occurs for a…
We analyze a toy model describing an empty spacetime in which the motion of a test mass (and the trajectories of photons) evidence the presence of a continuous and homogeneous distribution of matter; however, since the energy-momentum…
Pseudo-Newtonian gravitational potential describing the gravitational field of static and spherically symmetric black holes in the universe with a repulsive cosmological constant is introduced. In order to demonstrate the accuracy of the…
To be compatible with general relativity, every fundamental theory should be invariant under general coordinate transformations including spatial reflection. This paper describes an extension of the standard model in which the action is…
We clarify and extend further the idea developed in \cite{PKLMR,MLPR} that baryonic matter at high density has an emergent "pseudo-conformal symmetry." It is argued that as baryonic density exceeds $n \simeq n_{1/2} \gtrsim 2n_0$, a…
We explore General Relativity solutions with stealth scalar hair in general quadratic higher-order scalar-tensor theories. Adopting the assumption that the scalar field has a constant kinetic term, we derive in a fully covariant manner a…
Many different forms of the de Sitter metric in different coordinate systems are used in the general relativity literature. Two of them are the most common, the static form and the cosmological (exponentially expanding) form. The staticity…