Probing Lorentz symmetry violation using the first image of Sagittarius A*: Constraints on standard-model extension coefficients

Thanks to unparalleled near-horizon images of the shadows Messier 87* (M87*) and Sagittarius A* (Sgr A*) delivered by Event Horizon Telescope (EHT), two amazing windows opened up us for strong-field test gravity theories as well fundamental physics. Information recently published from EHT about Sgr A*'s shadow lets have a novel possibility exploration Lorentz symmetry violation (LSV) within Standard-Model Extension (SME) framework. Despite agreement between image prediction general theory relativity, there is still slight difference which expected be fixed taking some corrections into account. We bring idea that recent inferred explicable minimal SME-inspired Schwarzschild metric containing violating (LV) terms obtained post-Newtonian approximation. The LV embedded in are dimensionless spatial coefficients ${\bar s}^{jk}$ associated with field responsible LSV gravitational sector SME theory. In this way, one can control invariance allowed sensitivity level first A*. Actually, using bounds released $1\sigma$ uncertainty size whose fractional deviation standard Schwarzschild, we set upper limits different combinations diagonal time-time coefficient SME, well. best bound at $10^{-2}$ level, should interpreted differently those constraints previously extracted well-known frameworks since unlike studies it not Sun-centered celestial frame but comes probing black hole horizon scale.