Shadows, greybody factors, emission rate, topological charge, and phase transitions for a charged black hole with a Kalb-Ramond field background

In this work, we investigate a spherically symmetric charged black hole in the presence of a Kalb–Ramond field background. We calculate the photon sphere and shadow radii and, corroborating our results, we constrain them from observational data from the Event Horizon Telescope (EHT), particularly focusing on the shadow images of Sagittarius $A^{\ast }$. Additionally, we analyze the greybody factors, emission rate, and partial absorption cross section. We also examine the topological charge and its application to the deflection angle. Finally, we conduct the analysis of the heat capacity and phase transitions.