Dr. Savvas Koushiappas (Brown University)

Searching for a WIMP signal in the gamma-ray sky: Current status, results and challenges.

Indirect detection of dark matter is extremely important because it probes the same physics that took place in the early universe leading to the observed relic abundance. I will focus on the current state of dark matter annihilation searches, and latest results. In addition, I will discuss on how these results fit in the broad picture of dark matter physics and what are the key outstanding issues in this endeavor.

From Voids to Clusters:Gas and Galaxy Evolution in the Local Universe

Our understanding of the formation and evolution of galaxies and their large scale structure has advanced enormously over the last decade, thanks to an impressive synergy between theoretical and observational efforts. While the growth of the dark matter component seems well understood, the physics of the gas, during its accretion, removal and/or depletion is less well understood. Increasingly large scale optical surveys are tracing out the cosmic web of filaments and voids. Mathematical tools have been developed to describe these structures and to identify galaxies located in specific environments. HI imaging surveys begin to answer the question: how do galaxies get and lose their gas? The best evidence for ongoing gas accretion is found in the lowest density environments, while removal of gas in the highest density environments stops star formation and reddens the galaxies.

Refreshments will be served in CP 177 at 3:15 PM