Detection of neutrino induced cascades with radar
Neutrinos with energies above ~10 PeV have yet to be detected. These ultra-high energy (UHE) neutrinos are of significant interest from both particle-physics and astrophysical perspectives; the cross sections, as well as the sources, of such UHE neutrinos are not experimentally constrained. The main barrier to their detection is their extremely low flux. In order to reach higher energies, existing detectors (IceCube) must operate for many years, or new detectors must instrument extremely large volumes. To this end, radio-based methods have been put forward as a viable strategy due to their relatively low cost-per-volume. Radio systems detect the primary neutrino indirectly, by detecting (via radio) the cascade of secondary particles produced when a neutrino interacts in a medium, such as ice. In this talk, I will present very recent work on a radar-based radio detection scheme. In short, a volume of ice is illuminated by a radio-frequency field, and if an UHE neutrino produces a cascade within the volume, the incident field is scattered to a distant receiver. I will discuss recent experimental efforts to detect such reflections at SLAC, and some outlook on the sensitivity of a future detector system.
Cosmology from galaxy clustering and galaxy-galaxy lensing in the Dark Energy Survey
Weak gravitational lensing and galaxy clustering are powerful probes of many aspects of cosmology including dark energy, general relativity and neutrino physics. By combining these probes in photometric galaxy surveys, we can break nuisance parameter degeneracies and test the LCDM paradigm with high precision. I will be presenting the efforts of a one such analysis using the first 3 years of data from the Dark Energy Survey (DES). I will focus on the combination of angular galaxy clustering and the tangential shear around galaxies, discussing the requirements and prospects of this cosmological probe in DES and future surveys.