2019/07/31 by Zhaoting Chen, Wentao Luo, Yi-Fu Cai +1 · 1 citation
Physics and Astronomy · #astro-ph.CO #astro-ph.GA #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.102.104044
published as Phys. Rev. D 102, 104044 (2020) · 8 pages, 2 figures, comments are welcome. Updated with discussions on systematics to match the published version
arxiv created 2020/11/19 · arxiv updated 2020/11/25
We use galaxy-galaxy weak lensing data to perform a novel test on general relativity (GR) and f(T) torsional gravity. In particular, we impose strong constraints using the torsional (teleparallel) formulation of gravity in which the deviation from GR is quantified by a single parameter α, an approximation which is always valid at low-redshift Universe and weak gravitational fields. We calculate the difference in the deflection angle and eventually derive the modified excess surface density profile, which is mainly affected at small scales. Confronting the predictions with weak lensing data from the Sloan Digital Sky Survey Data Release 7, we obtain the upper bound on the deviation parameter, which, expressed via the dimensionless percentage in the Universe energy content, reads as \rmlog10Ωα≤ -18.52-0.42+0.80(stat)-0.37+1.50(sys) [Rc/0.015R200] with systematics mainly arising from the modelling of astrophysics, upon a reasonable choice of cut-off radius for f(T) gravity in form of T + αT2. To our knowledge, this is the first time that GR is verified at such an accuracy at the corresponding scales.