10.18453/rosdok_id00001585 Som, Sunipa Sunipa Som http://d-nb.info/gnd/1075019222 Universität Rostock 2015 530 Physics 2015 en http://purl.uni-rostock.de/rosdok/id00001585 urn:nbn:de:gbv:28-diss2015-0135-2 This thesis is a theoretical investigation of the relaxation behaviour of excitons in Cuprous Oxide at ultra low temperatures when the excitons are confined within a potential trap and also in a homogeneous system. Under the action of deformation potential phonon scattering only, Bose Einstein Condensation (BEC) occurs for all temperatures in the investigated range. In the case of Auger decay, we do not find at any temperature a BEC due to the heating of the exciton gas. In the case of elastic and phonon-scattering together BEC occurs in this case of 0.1 K.