The PI will carry out theoretical investigations to maximize the scientific return from surveys of the Sunyaev-Zeldovich Effect (SZE) in galaxy clusters, and to motivate measurements of the polarization and temperature anisotropies of the Cosmic Microwave Background radiation (CMB) with an angular resolution five to ten times better than that of planned space missions. Those observations will tighten the current cosmological parameter constraints as well as provide very restrictive limits on the dark energy equation of state and on the neutrino mass. For the SZE surveys the investigation will focus on galaxy cluster peculiar velocities and how to use them as cosmological probes in a way expected to be highly complementary to supernova observations. By creating synthetic multi-frequency observations of galaxy clusters, and studying the dependence on experimental parameters and cluster parameters, the project will also understand the rewards of peculiar velocity observations and how to reap those rewards. The developed tools will help in other areas, such as how to make galaxy cluster number counts a precision cosmological probe.
Constraining cosmological parameters with high-resolution CMB data is complicated by the interaction of the CMB photons with the local Universe, via Thomson scattering and gravitational lensing. However, these complications can also prove a boon since they offer a means of probing the dark energy and the dark ages. This work will produce forecasts that take into account these higher order effects, and will quantify how well higher order statistics can be used to probe the dark energy and the dark ages. These results will guide the design of planned instruments, perhaps motivate new ones, and lay the groundwork for future data analysis.
Two undergraduates (including one from an under-represented group) and two graduate students each year will contribute to the research program. Materials from the research program will be used in a lower division astronomy course, an upper division astrophysics course, and an advanced graduate course. There will also be public lectures about the results and a generally accessible web site to be created by an undergraduate student.
