Scalar fields properties for flat galactic rotation curves
نویسنده
چکیده
The whole class of minimally coupled and massive scalar fields which may be responsible for flattening of galactic rotation curves is found. An interesting relation with a class of scalar-tensor theories able to isotropise anisotropic models of Universe is shown. The resulting metric is found and its stability and scalar field properties are tested with respect to the presence of a second scalar field or a small perturbation of the rotation velocity at galactic outer radii. Published in Astronomy and Astrophysics, 413, p 799, 2004
منابع مشابه
Generalized Einstein theory on solar and galactic scales.
We study a generalized Einstein theory with the following two criteria:i) on the solar scale, it must be consistent with the classical tests of general relativity, ii) on the galactic scale, the gravitational potential is a sum of Newtonian and Yukawa potentials so that it may explain the flat rotation curves of spiral galaxies. Under these criteria, we find that such a generalized Einstein act...
متن کاملGalaxy rotation curves: the effect of the Ampere force
Using an example of the galaxy, an attempt is made to explain the flat rotational curves of gas and plasma in galaxies by means of the Ampere force. Using acceptable models for the galactic magnetic field and plausible physical parameters, we find that the flat rotational curves for gas and plasma can be obtained based purely on the observed baryonic (visible) matter distribution and the ampere...
متن کاملLate-time phase transition and the galactic halo as a Bose liquid.
In the previous work, we investigated the rotation curves of galaxies assuming that the dark matter consists of ultra light boson appearing in ′ late time phase transition' theory. Generalizing this work, we consider the effect of visible matter and classify the types of rotation curves as we vary the fraction of the mass and extention of visible matter. We show that visible matter, in galaxies...
متن کاملar X iv : a st ro - p h / 96 05 08 5 v 1 1 5 M ay 1 99 6 Are Galactic Rotation Curves Really Flat ? ∗
In this paper we identify a new regularity in the systematics of galactic rotation curves, namely we find that at the last detected points in galaxies of widely varying luminosity, the centripetal acceleration is found to have the completely universal form v 2 /R = c 2 (γ 0 + γ * N *)/2 where γ 0 and γ * are new universal constants and N * is the amount of visible matter in each galaxy. This re...
متن کاملGalaxy rotation curves without non-baryonic dark matter and modifications to gravity: effect of the Ampere force
Using an example of the galaxy, an attempt is made to explain the flat rotational curves of galaxies by means of the Ampere force. This is the first attempt of fitting the rotational curve without both non-baryonic dark matter and modifications to gravity. Using acceptable models for the galactic magnetic field and plausible physical parameters, we find that the flat rotational curves can be ob...
متن کامل