2020/01/02 by J. W. Moffat
Physics and Astronomy · #gr-qc #astro-ph.CO
paper · pdf · doi:10.1140/epjc/s10052-020-08482-x
published as The European Physical Journal C (2020) 80:906 · 9 pages, 2 figures. arXiv admin note: substantial text overlap with arXiv:1409.0853, arXiv:1510.07037
arxiv created 2020/01/02 · arxiv updated 2020/10/30
A modified gravitational theory explains early universe and late time cosmology, galaxy and galaxy cluster dynamics. The modified gravity (MOG) theory extends general relativity (GR) by three extra degrees of freedom: a scalar field G, enhancing the strength of the Newtonian gravitational constant GN, a gravitational, spin 1 vector graviton field ϕμ, and the effective mass μ of the ultralight spin 1 graviton. For t < t\rm rec, where t\rm rec denotes the time of recombination and re-ionization, the density of the vector graviton ρϕ> ρb, where ρb is the density of baryons, while for t > t\rm rec we have ρb > ρϕ. The matter density is parameterized by ΩM=Ωb+Ωϕ+Ωr where Ωr=Ωγ+Ων. For the cosmological parameter values obtained by the Planck Collaboration, the CMB acoustical oscillation power spectrum, polarization and lensing data can be fitted as in the ΛCDM model. When the baryon density ρb dominates the late time universe, MOG explains galaxy rotation curves, the dynamics of galaxy clusters, galaxy lensing and the galaxy clusters matter power spectrum without dominant dark matter.