I am interested in relationships between geometry, gauge- and string theories. In the past, I have mainly worked on problems regarding gauge/string duality, specifically the case of gauge theories with additional fundamental matter fields. On the string theory side of the duality, these are represented by D-brane sources, which can be conveniently described by the mathematics of generalized calibrations. Just as calibrations capture the physics of D-branes, G-structures provide a very natural language to address issues regarding the involved supergravity backgrounds themselves.