TAPIR Seminar

Despite being ubiquitous throughout the Universe, the fundamental physics governing dark matter and the origin of neutrino mass remains a mystery. While this physics plays little role in the current evolution of cosmic structures, it did have a major impact in the early epochs of the Universe on the evolution of cosmological density fluctuations on small causal length scales. Studying the astrophysical structures that resulted from the gravitational collapse of fluctuations on these small scales can thus yield important clues about the physics of dark matter and neutrinos. Today, most of these structures are locked in deep inside the potential wells of massive galaxies, making the study of their properties difficult. Fortunately, due to fortuitous alignments between high-redshift bright sources and us, some of these galaxies act as spectacular strong gravitational lenses, allowing us to probe their inner structures. In this talk, we present a new statistical analysis formalism to extract information about mass substructures inside lens galaxies by combining lensing probes.  We determine which properties of mass substructures are most readily constrained by lensing data and forecast the constraining power of current and future observations. We comment on what these constraints imply for neutrino and dark matter physics.