10.18453/rosdok_id00002484 Karsten, Sven Sven Karsten http://d-nb.info/gnd/1190746840 Universität Rostock 2018 530 Physics 2018 en http://purl.uni-rostock.de/rosdok/id00002484 urn:nbn:de:gbv:28-rosdok_id00002484-6 The goal of this thesis is to bridge the gap between the two standard theoretical approaches to vibronic spectroscopy via trajectory-based methods. As the starting point, a generalized time-correlation function is introduced and the ring-polymer molecular dynamics method is generalized to vibronic transitions, yielding an improvement over known classical approximations. Further, the vibronic spectrum is evaluated via the Matsubara dynamics. Employing an ad-hoc modification, the sign problem of the Matsubara method can be circumvented and the spectra of model systems are adequately simulated.