32 Bissok, Martin Wiebusch, Christopher Hebbeker, Thomas 133510 133110 130000 Publikationsserver der RWTH Aachen University Aachen English XIII, 165 S. : Ill., graph. Darst. The search for a comprehensive theory of dark matter is one of the major fields of activity in particle astrophysics, cosmology and particle physics. Aftermore than 80 years of research since the first evidence for its existence, much has been learned, yet the nature of dark matter is unknown. It is clear, that a non-baryonic, non-radiating kind of matter makes up more than 25% of the energy density of the Universe. The gravitational interaction of dark matter with the visible Universe allows for a spatial mapping of the dark matter distribution on different scales, ranging from galaxies to clusters and large-scale filaments. However, dark matter has so far eluded a detection beyond inference from gravitational interaction. Indirect searches for dark matter attempt to detect a flux of messenger particles from dark matter annihilation or decay, originating from regions of increased dark matter density. This thesis describes the search for a flux of neutrinos from dark matter annihilation in the Galactic center with IceCube-79. The dark matter density is expected to peak in the Galactic center region, thus yielding the highest expected flux of final state particles. However, for IceCube the Galactic center is located in the southern hemisphere, thus the background of atmospheric muons from that direction provides a major challenge for this analysis. Dedicated techniques to veto this background are developed and discussed. Finally, a likelihood analysis is performed, that exploits the spatial shape of the expected flux. The result is compatible with the null hypothesis, and limits are set on the self-annihilation cross-section for a mass range from 100GeV to10TeV, and several benchmark annihilation channels. The most constraining limit for direct annihilation to neutrinos reaches down to 10e-23 cm^3/s at a mass of 100GeV. Finally, the limits are compared to other experimental results, and possible improvements to this analysis are discussed. Aachen, Techn. Hochsch., Diss., 2015 ; PUB:(DE-HGF)11, ; 2, ; Dissertation / PhD Thesis Dissertation Aachen, Techn. Hochsch. 2015 RWTH-2015-04606 2015 https://publications.rwth-aachen.de/record/482054