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Abstract

Binary stellar interactions that take place on dynamical timescales are some of the most challenging processes to model in astronomy, and are best described by multidimensional, multi-physics simulations. The focus of this thesis is on the numerical modeling of some of the least explored stellar interactions, with a spe- cial emphasis on those involving white dwarfs. This work presents three different studies using three-dimensional hydrodynamic simulations. In the first place, the emission of gravitational waves during common-envelope events is studied, esti- mating the chances for their detection with future space-based detectors. Secondly, the tidal disruption of a white dwarf by a neutron star is studied, showing how the accurate modeling of these events requires the inclusion of a multitude of physi- cal processes including magnetic fields, nuclear reactions and neutrino emission. Finally, through a third simulation, it is shown how mergers between low-mass white dwarfs, with total masses substantially below the Chandrasekhar limit, can lead to thermonuclear explosions under the right conditions. The results of this thesis stress how dynamical interactions between stars can produce a multitude of bright transients, and how the use of advanced multidimensional, multi-physics codes for their modeling will help improve our understanding of the physics and processes involved.