Executive Summary : | The absorption of light in materials has been a focus of non-destructive probing in condensed matter and materials sciences. Techniques like angle resolved photoemission spectroscopy (ARPEs) and electron energy loss spectroscopy (EELs) capture the single-particle spectral function, which helps understand how light is absorbed and scattered by materials at the microscopic level. Excitons, electron-hole pairs bounded together via a Coulombic force of attraction, are often generated through external perturbations like light. The many body perturbation theory (MBPT) approach is a reliable theoretical approach to investigate exciton-driven optical spectra in bulk and low dimensional materials. This study extends understanding for finite temperature exciton characters in 2D materials, obtaining excitonic spectra at finite wavevectors. The proposal also probes various optical nonlinear coefficients and strong pulse excitations by solving a more generalized time-dependent BsE. |