Derivation of the Tully-Fisher law: Doubts about the necessity and existence of halo dark matter

Moshe Carmeli

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

For disk galaxies the fourth power of the circular velocity v4c of stars around the core of the galaxy is proportional to the luminosity L, v4c ∝ L (Tully-Fisher law). Since L is proportional to the mass M of the galaxy, it follows that v4c ∝ M. Newtonian mechanics, however, yields v2c = GM/r for a circular motion. In order to rectify this big difference, astronomers assume the existence of dark matter. We derive the equation of motion of a star moving in the central field of a galaxy and show that, for a circular motion, it yields a term of the form v4c ∝ GMc/τ, where G is Newton's gravitational constant, c is the speed of light, and τ is the Hubble time. This puts in doubt the existence of halo dark matter for galaxies.

Original languageEnglish
Pages (from-to)1397-1404
Number of pages8
JournalInternational Journal of Theoretical Physics
Volume39
Issue number5
DOIs
StatePublished - 1 Jan 2000

ASJC Scopus subject areas

  • General Mathematics
  • Physics and Astronomy (miscellaneous)

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