For refcode 2017ApJ...849..158M: Retrieve 2 NED objects in this reference. Please click here for ADS abstract
NED Abstract
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2017ApJ...849..158M
Dynamical Effects of the Scale Invariance of the Empty Space: The Fall of
Dark Matter?
Maeder, Andre
Abstract. The hypothesis of the scale invariance of the macroscopic empty
space, which intervenes through the cosmological constant, has led to new
cosmological models. They show an accelerated cosmic expansion after the
initial stages and satisfy several major cosmological tests. No unknown
particles are needed. Developing the weakfield approximation, we find
that the herederived equation of motion corresponding to Newton's
equation also contains a small outward acceleration term. Its order of
magnitude is about {sqrt}{{{rho}}_{{c_}}/{rho}} x Newton's gravity (varrho
being the mean density of the system and {{rho}}_{{c_}} the usual critical
density). The new term is thus particularly significant for very low
density systems. A modified virial theorem is derived and applied to
clusters of galaxies. For the Coma Cluster and Abell 2029, the dynamical
masses are about a factor of 510 smaller than in the standard case. This
tends to leave no room for dark matter in these clusters. Then, the
twobody problem is studied and an equation corresponding to the Binet
equation is obtained. It implies some secular variations of the orbital
parameters. The results are applied to the rotation curve of the outer
layers of the Milky Way. Starting backward from the present rotation
curve, we calculate the past evolution of the Galactic rotation and find
that, in the early stages, it was steep and Keplerian. Thus, the flat
rotation curves of galaxies appear as an age effect, a result consistent
with recent observations of distant galaxies by Genzel et al. and Lang et
al. Finally, in an appendix we also study the longstanding problem of the
increase with age of the vertical velocity dispersion in the Galaxy. The
observed increase appears to result from the new small acceleration term
in the equation of the harmonic oscillator describing stellar motions
around the Galactic plane. Thus, we tend to conclude that neither dark
energy nor dark matter seems to be needed in the proposed theoretical
context.
Key words: cosmology: theory, dark energy, dark matter, Galaxy: kinematics
and dynamics
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