2009/01/23 by Xue-Mei Deng, Yi Xie, Tian-Yi Huang · 1 citation
Physics and Astronomy · #gr-qc
paper · pdf · doi:10.1103/physrevd.79.044014
published as Phys.Rev.D79:044014,2009 · 39 pages, 4 figures, accepted by PRD
arxiv created 2009/01/23 · arxiv updated 2009/12/01
A gravity theory called scalar-tensor-vector gravity (STVG) has been recently developed and succeeded in solar system, astrophysical and cosmological scales without dark matter [J. W. Moffat, J. Cosmol. Astropart. Phys. 03, 004 (2006)]. However, two assumptions have been used: (i) B(r)=A-1(r), where B(r) and A(r) are g00 and grr in the Schwarzschild coordinates (static and spherically symmetric); (ii) scalar field G=Const. in the solar system. These two assumptions actually imply that the standard parametrized post-Newtonian parameter γ=1. In this paper, we relax these two assumptions and study STVG further by using the post-Newtonian (PN) approximation approach. With abandoning the assumptions, we find γ≠1 in general cases of STVG. Then, a version of modified STVG (MSTVG) is proposed through introducing a coupling function of scalar field G: θ(G). We have derived the metric and equations of motion (EOM) in 1PN for general matter without specific equation of state and N point masses firstly. Subsequently, the secular periastron precession ω of binary pulsars in harmonic coordinates is given. After discussing two PPN parameters (γ and β) and two Yukawa parameters (α and λ), we use ω of four binary pulsars data (PSR B1913+16, PSR B1534+12, PSR J0737-3039 and PSR B2127+11C) to constrain the Yukawa parameters for MSTVG: λ=(3.97±0.01)×108m and α=(2.40±0.02)×10-8 if we fix |2γ-β-1|=0.