Galactic rotation curves in brane world models

L. Gergely, T. Harko, M. Dwornik, G. Kupi, Z. Keresztes

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

In the brane world scenario the four-dimensional effective Einstein equation has extra source terms, which arise from the embedding of the three-brane in the bulk. These non-local effects, generated by the free gravitational field of the bulk, may provide an explanation for the dynamics of the neutral hydrogen clouds at large distances from the galactic centre, which is usually explained by postulating the existence of the dark matter. In the present paper we consider the asymptotic behaviour of the galactic rotation curves in the brane world models, and compare the theoretical results with observations of both high surface brightness and low surface brightness galaxies. For the chosen sample of galaxies we determine first the baryonic parameters by fitting the photometric data to the adopted galaxy model; then we test the hypothesis of the Weyl fluid acting as dark matter on the chosen sample of spiral galaxies by fitting the tangential velocity equation of the combined baryonic-Weyl model to the rotation curves. We give an analytical expression for the rotational velocity of a test particle on a stable circular orbit in the exterior region to a galaxy, with Weyl fluid contributions included. The model parameter ranges for which the χ2 test provides agreement (within 1σ confidence level) with observations on the velocity fields of the chosen galaxy sample are then determined. There is a good agreement between the theoretical predictions and observations, showing that extra-dimensional models can be effectively used as a viable alternative to the standard dark matter paradigm.

Original languageEnglish
Pages (from-to)3275-3290
Number of pages16
JournalMonthly Notices of the Royal Astronomical Society
Volume415
Issue number4
DOIs
Publication statusPublished - Aug 2011

Fingerprint

galactic rotation
galaxies
curves
dark matter
brightness
hydrogen clouds
fluid
fluids
circular orbits
Einstein equations
spiral galaxies
embedding
gravitational fields
confidence
velocity distribution
world
hydrogen
prediction
predictions
test

Keywords

  • Dark matter
  • Galaxies: haloes
  • Gravitation: relativistic processes

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Galactic rotation curves in brane world models. / Gergely, L.; Harko, T.; Dwornik, M.; Kupi, G.; Keresztes, Z.

In: Monthly Notices of the Royal Astronomical Society, Vol. 415, No. 4, 08.2011, p. 3275-3290.

Research output: Contribution to journalArticle

Gergely, L. ; Harko, T. ; Dwornik, M. ; Kupi, G. ; Keresztes, Z. / Galactic rotation curves in brane world models. In: Monthly Notices of the Royal Astronomical Society. 2011 ; Vol. 415, No. 4. pp. 3275-3290.
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