Anthony Aguirre has a diverse set of research interests, covering (i) early-universe cosmology, with special emphasis on cosmological inflation and eternal inflation, (ii) heavy element enrichment of the intergalactic medium, and (iii) dark matter in the first (Population III) stars. Piero Madau engages in research on theoretical cosmology and the high-redshift universe, especially on the physics of the intergalactic medium and the history of star formation in galaxies, including the problem of determining the impact of reionization on several key cosmological issues. Madau also works in high-energy astrophysics, on problems related to accretion onto compact objects, the origin of the cosmic X-ray background, and gamma-ray bursts. Joel Primack specializes in the formation and evolution of galaxies and the nature of the dark matter that makes up most of the matter in the universe. Primack also is director of the University of California High-Performance AstroComputing Center, and he organized the first UC-HIPACC International School on AstroComputing at UCSC, the annual UCSC Galaxy Workshop, and the UC-HIPACC conference on The Future of AstroComputing at the San Diego Supercomputing Center. Enrico Ramirez-Ruiz is the director of the Theoretical Astrophysics in Santa Cruz (TASC) multi-departmental Center, and his research focuses on the violent universe with an emphasis on stellar explosions, gamma-ray bursts, and accretion phenomena near compact objects; Ramirez-Ruiz's current goal is to combine high quality numerical simulations with analytical techniques in order to address basic questions in high energy astrophysics.