Connecting Fundamental Physics and Cosmology

Syracuse University, Syracuse NY

Investigators

Abstract

Abstract: PHY - 0653563 Title: Connecting Fundamental Physics and Cosmology PI Mark Trodden Institution: Syracuse University The case for cosmic acceleration presents cosmology with two of its most pressing problems: the magnitude of the dark energy, since the expected size of the cosmological constant is entirely inconsistent with observation; and the coincidence problem - why is the fraction of the critical density in dark energy is the same order of magnitude as that in matter today. These concerns join other fundamental unsolved problems - the nature of dark matter, the origin of the baryon asymmetry, and the fundamental origin of inflation or other physics of the early universe. A central part of the proposal is the development of a suite of tests to (a) establish the theoretical viability of dark energy and modified gravity models and (b) to distinguish such models from one another and from the default case of a cosmological constant. The P.I. will investigate the extent to which there are relationships between modified gravity and dark energy models; the P.I. will map out and explore the territory of possible modifications to gravity with the potential to drive late-time cosmic acceleration; and the P.I. will perform a general study of cosmological perturbation theory in modified source gravity and on a class of models in which the Gravitational action is a general function of curvature invariants. The P.I. further proposes to carry out a systematic and comprehensive analysis of coupled dark energy-matter models, focusing on the stability of these models. The P.I. also proposes a systematic study of the cosmological consequences of models arising from compactified higher dimensional theories of particle physics and gravity; in particular, whether there are specific signatures that might be accessible to future supernovae studies, lensing surveys, large-scale structure measurements and collider experiments. The dominant broader impact of the proposed research is in public science education; bringing cutting edge science to the public, including populations traditionally underrepresented in physics. The P.I. has been a co-P.I. on Cosmic Connections, an NSF-funded project to construct modern cosmology exhibits for display in the Milton J. Rubenstein Museum of Science and Technology in Syracuse. The P.I. also organizes a public lecture series - Saturday Morning Physics - to share the ideas and excitement of cutting edge modern physics with people with no previous science education. Further, the P.I. has co-founded and organizes Café Scientifique Syracuse. Held at a downtown restaurant, Cafe Scientifique is a place where scientists and scientifically interested non-scientists can come together informally to hear about and discuss interesting science.