To obtain a unified framework for symmetric and asymmetric heterotic orbifold constructions we provide a systematic study of Narain compactifications orbifolded by finite order T -duality subgroups. We review the generalized vielbein that parametrizes the Narain moduli space (i.e. the metric, the B-field …

A program that automatically detects auroral events in all-sky images taken by the all-sky camera of IRF has been written. Current programs that automatically detect the aurora in all-sky images using the RGB color system often miss strong aurora and sometimes interprets clouds as aurora. To improve …

Earth’s magnetic field, also known as the geomagnetic field, interacts with the solar wind, a stream of charged particles originating from the Sun. The interaction causes the geomagnetic field to undergo variations, called geomagnetic disturbances or geomagnetic activity. This bachelor thesis features …

Scanning tunneling microscopy is an important and enabling tool for condensed matter physics and surface science. The low temperature STM in Leiden (Prof. J. Van Ruitenbeek and Prof J. Aarts) is used for research in the field of atomic/molecular electronics and superconductivity. The current low temperature …