Thermal fluctuations, deflection angle and greybody factor of a high-dimensional Schwarzschild black hole in STVG

In this work, we study the thermal fluctuations, deflection angle and greybody factor of the high-dimensional Schwarzschild black hole in scalar-tensor-vector gravity (STVG). We calculate some thermodynamic quantities related to the correction of black hole entropy caused by thermal fluctuations and discuss the effect of the correction parameters on these quantities. By analysing the changes in the corrected specific heat, we find that thermal fluctuations make the small-sized black hole more stable. It is worth noting that the STVG parameter does not affect the thermodynamic stability of this black hole. Additionally, by utilizing the Gauss-Bonnet theorem, the deflection angle is obtained in the weak field limit and the effect of two parameters on the results is visualized. Finally, we calculate the bounds on greybody factor of a massless scalar field. We observe that as the STVG parameter around black hole increases, the weak deflection angle becomes larger and the more scalar particles can reach infinity. However, the spacetime dimension has the opposite effect to the STVG parameter on the weak deflection angle and greybody factor.