Florian Marquardt leads the theory division at the Max Planck Institute for the Science of Light (MPL) in Erlangen, Germany. He had studied in Bayreuth, Germany, before doing his PhD at the university of Basel, Switzerland. From 2003 to 2005, he was a postdoctoral fellow at Yale University, USA, after which he took up a junior research group leader position at the LMU Munich (2005-2010). In 2009 he was awarded the Walter Schottky prize of the German Physical Society for his work on the theory of cavity optomechanics. In 2010, he moved to a tenured (chair) position at the university of Erlangen. He was appointed a director at the MPL in 2016. His research interests generally lie at the intersection of nanophysics and quantum optics, including cavity optomechanics and nanomechanics, decoherence, quantum transport, quantum electrodynamics in superconducting circuits, quantum computation, and quantum many-body physics. ABSTRACT: During the last ten years, a new research frontier has been explored at the interface between nanophysics and quantum optics: in the field of cavity optomechanics, one aims to exploit the interaction between radiation and vibrational motion, often at the nanoscale. Possible applications range from foundational studies of quantum physics via sensitive measurements to quantum communication. In this talk, I will first give an overview of the current status of this field and then highlight two recent research topics: the study of the topological transport of photons and phonons, and the optomechanics of superfluid helium. The colloquium will be live-streamed from the ICTP website at: ictp.it/livestream Light refreshments will be served after the event.