Related papers: Constraining Alternative Gravity Theories Using Th…
New f(R,T) model of gravitation, introduced previously by the author, is considered. It is based on an affine geometrical construction in which the torsion is a dynamical field, the coupling is minimal and the theory is Lorentz invariant by…
In this work, we study spherically symmetric vacuum solutions in 1-parameter New General Relativity (NGR), a specific theory in teleparallel gravity which is constructed from the three possible quadratic scalars obtained from torsion with…
We develop the approach to the problem of neutrino oscillations in a magnetic field introduced in \cite{Popov:2019nkr} and extend it to the case of three neutrino generations. The theoretical framework suitable for computation of the Dirac…
In screening models with scalar-matter conformal coupling, we study the flavor transition of neutrinos. We employ an analytical method for studying the oscillation phase in a spherically symmetric spacetime filled by a scalar field. Since…
The future finite-time singularities emerging in alternative gravity dark energy models are classified and studied in Jordan and Einstein frames. It is shown that such singularity may occur even in flat spacetime for the specific choice of…
We present a solution of the solar neutrino deficit using three flavors of neutrinos within the R-parity non-conserving supersymmetric model. In vacuum, mass and mixing is restricted to the nu(mu)-nu(tau) sector only, which we choose in…
We propose an alternative description of the Schwarzschild black hole based on the requirement that the solution be static not only outside the horizon but also inside it. As a consequence of this assumption, we are led to a change of…
It is broadly known that Lie point symmetries and their subcase, Noether symmetries, can be used as a geometric criterion to select alternative theories of gravity. Here, we use Noether symmetries as a selection criterion to distinguish…
Rastall's theory belongs to the class of non-conservative theories of gravity. In vacuum, the only non-trivial static, spherically symmetric solution is the Schwarzschild one, except in a very special case. When a canonical scalar field is…
We investigate static and spherically symmetric vacuum solutions in the symmetric teleparallel $f(\mathbb{Q})$ modified theory of gravity. Starting from a recently proposed classification of affine connections compatible with both the…
Gravitational theories generated from Lagrangians of the form f(R) are considered. The spherically symmetric solutions to these equations are discussed, paying particular attention to features that differ from the standard Schwarzschild…
Solutions of field equations in $f(R)$ gravity are found for a spherically symmetric and static spacetime in the Born-Infeld (BI) non-linear electrodynamics. It is found that the models supported in this configuration must have the…
There are a number of publications on relativistic objects dealing either with black holes or naked singularities in the center. Here we show that there exist static spherically symmetric solutions of Einstein equations with a strongly…
We present new second derivative, generally covariant theories of gravity for spherically symmetric spacetimes (general covariance is in the $t-r$ plane) belonging to the class where the spherically symmetric Einstein-Hilbert theory is…
The symmetry of the problem of the apparent deficit in upward-going atmospheric muon neutrinos reveals two possible, nonexclusive kinds of solution: Nonlinearity in distance or nonlinearity in angle of observation. Nonlinearity in distance…
We give a phenomenological interpretation of atmospheric and solar neutrino oscillations by considering two scenarios for the neutrino mass spectrum: (a) m_1 \ll m_2 \ll m_3 and (b) m_1 \approx m_2 \approx m_3. A new parametrization of the…
Weak field approximate solutions in the Lambda-->0 limit of a model of de Sitter gravity have been presented in the static and spherically symmetric case. Although the model looks different from general relativity, among those solutions,…
In this thesis we explore the implications of neutrino oscillations in the context of the solar neutrino data, the atmospheric neutrino data and results from the terrestrial accelerator/reactor neutrino oscillation experiments. We perform…
We investigate static spherically symmetric solutions within the framework of the local limit of nonlocal gravity. This theory departs from Einstein's general relativity (GR) through the introduction of a scalar gravitational susceptibility…
We review the application of the relativistic quantum mechanics method for the description of neutrino oscillations for the studies of spin-flavor oscillations in background matter under the influence of a plane electromagnetic wave. Basing…