arXiv subjects
Publications and source records attributed to P. Fiziev.
We consider: minimal scalar-tensor model of gravity with Brans-Dicke factor $ω(Φ)\equiv 0$ and cosmological factor $Π(Φ)$; restrictions on it from gravitational experiments; qualitative analysis of new approach to cosmological constant problem based on the huge amount of action in Universe; determination of $Π(Φ)$ using time evolution of scale factor of Universe.
In the framework of a model of minimal of dilatonic gravity (MDG) with cosmological potential we consider: the relations of MDG with nonlinear gravity and string theory; natural cosmological units, defined by cosmological constant; the properties of cosmological factor, derived from solar system and Earth-surface gravitational experiments; universal anty-gravitational interactions, induced by positive cosmological constant and by Nordtved effect; a new formulation of cosmological constant problem using the ratio of introduced cosmological action and Planck constant $\sim 10 ^{122}$;qualitative analysis of this huge number based on classical action of effective Bohr hydrogen atoms; inverse cosmological problem: to find cosmological potential which yields given evolution of the RW Universe; and comment other general properties of MDG.
We study equilibrium configurations of boson stars in the framework of a class scalar-tensor theories of gravity with massive gravitational scalar (dilaton). In particular we investigate the influence of the mass of the dilaton on the boson star structure. We find that the masses of the boson stars in presence of dilaton are close to those in general relativity and they are sensitive to the ratio of the boson mass to the dilaton mass within a typical few percent. It turns out also that the boson star structure is mainly sensitive to the mass term of the dilaton potential rather to the exact form of the potential.
We develop the general theory of stars in Saa's model of gravity with propagating torsion and study the basic stationary state of neutron star. Our numerical results show that the torsion force decreases the role of the gravity in the star configuration leading to significant changes in the neutron star masses depending on the equation of state of star matter. The inconsistency of the Saa's model with Roll-Krotkov-Dicke and Braginsky-Panov experiments is discussed.
We propose a novel self consistent minimal coupling principle in presence of torsion dilaton field. This principle yields a new local dilatation symmetry and predicts the interactions of torsion dilaton with the real matter and with metric. The soft violation of this symmetry yields a physical dilaton and a simple relation between Cartan scalar curvature and cosmological constant in this new model of gravity with propagating torsion. Its relation with scalar-tensor theories of gravity and a possible use of torsion dilaton in the inflation scenario is discussed. \noindent{PACS number(s): 04.50.+h, 04.40.Nr, 04.62.+v}
We present a review of some recent models of gravitation theory with propagating torsion based on the use of a torsion-dilaton field and propose one more model of this type which promises to be more realistic. A proper universal self-consistent minimal action principle yields the properties of this model and predicts the interactions of torsion-dilaton field with the real matter. The new model may be compatible with the string models with dilaton field and gives a novel interpretation of the dilaton as a part of the space-time torsion. A relation with some recent models of dilatonic gravity is also possible.
It's shown that Saa's model of gravity with propagating torsion is inconsistent with basic solar-system gravitational experiments.
It is shown that the recently proposed interpretation of the transposed equi-affine theory of gravity as a theory with variable Plank "constant" is inconsistent with basic solar system gravitational experiments.
We exhibit the transformation properties of the mechanical action principle under anholonomic transformations. Using the fact that spaces with torsion can be produced by anholonomic transformations we derive the correct action principle in these spaces which is quite different from the conventional action principle.
We present a derivation of the Schrödinger equation for a path integral of a point particle in a space with curvature and torsion which is considerably shorter and more elegant than what is commonly found in the literature.
We use a recently developed action principle in spaces with curvature and torsion to derive the Euler equations of motion for a rigid body within the body-fixed coordinate system. This serves as an example that the particle trajectories in a space with curvature and torsion follow the straightest paths (autoparallels), not the shortest paths (geodesics), as commonly believed.
To comply with recent developments of path integrals in spaces with curvature and torsion we find the correct variational principle for the classical trajectories. Although the action depends only on the length, the trajectories are {\em autoparallels} rather than geodesics due to the effects of a new torsion force.