Past Events
| Event | Date | Summary |
| Tim Linden (Ohio State University) | Thu. October 4th, 2018 4:00 pm-5:00 pm |
2018 Michelson Postdoctoral Prize Lecture 3: Colloquium Indirect Searches for Weakly-Interacting Massive Particles Recent observations at gamma-ray and radio energies, as well as local observations of charged cosmic-rays, have placed increasingly stringent constraints on the annihilation cross-section of Weakly Interacting Massive Particle (WIMP) dark matter. Excitingly, these studies have begun to rule out the infamous “thermal annihilation cross-section”, where WIMP models are expected to naturally obtain the observed relic abundance. As expected when multiple cutting-edge observations coincide, there is currently tension between different studies. For example, strong limits from gamma-ray searches in dwarf-spheroidal galaxies lie in significant tension with dark matter explanations for the observed “Galactic Center excess” observed near the center of the Milky Way. |
| Tim Linden (Ohio State University) | Tue. October 2nd, 2018 11:30 am-12:30 pm |
2018 Michelson Postdoctoral Prize Lecture 2 The Rise of the Leptons: Emission from Pulsars will Dominate the next Decade of TeV Gamma-Ray Astronomy HAWC observations have detected extended TeV emission coincident with the Geminga and Monogem pulsars. In this talk, I will show that these detections have significant implications for our understanding of pulsar emission. First, the spectrum and intensity of these “TeV Halos” indicates that a large fraction of the pulsar spindown energy is efficiently converted into electron-positron pairs. This provides observational evidence necessitating pulsar interpretations of the rising positron fraction observed by PAMELA and AMS-02. |
| Tim Linden (Ohio State University) | Mon. October 1st, 2018 12:45 pm-1:45 pm |
Michelson Postdoctoral Prize Lecture 1 Astrophysical Signatures of Dark Matter Accumulation in Neutron Stars Over the past few decades, terrestrial experiments have placed increasingly strong limits on the dark matter-nucleon scattering cross-section. However, a significant portion of the standard dark matter parameter space remains beyond our reach. Due to their extreme density and huge gravitational fields, neutron stars stand as optimal targets to probe dark matter-nucleon interactions. For example, over the last few years, the mere existence of Gyr-age neutron stars has placed strong limits on models of asymmetric dark matter. In this talk, |