Theoretical Physics: LHC, Gravity, Cosmology

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This award funds the research activities of Professors Marc Kamionkowski and David E. Kaplan at Johns Hopkins University. The aim of particle physics is to understand the fundamental laws of physics and the rules that govern the behavior of all physical systems in the Universe. The traditional avenues for progress in this endeavor have over the past century been experiments at particle colliders, the most recent such experiment being the Large Hadron Collider (LHC), a major international collaboration with significant US participation. Another avenue has been to use observations of astrophysical systems, as well as the Universe as a whole, as a laboratory for fundamental physics, as these cosmic systems must also obey the laws of physics. In their research, Professors Kamionkowski and Kaplan aim to develop new hypotheses about the fundamental laws of physics and to develop analytic tools to capitalize fully, in our effort to uncover new physical laws, upon the nation's investment in collider and cosmic experiments. Research on this subject advances the national interest by promoting the advancement of science in its most fundamental direction. It also advances the national interest by attracting young talent to STEM fields and providing them with powerful analytic tools in order to drive the type of innovation that drives economic progress. This project will also have broader impacts through the training of graduate students who will serve as apprentices in the research. Professors Kamionkowski and Kaplan also intend to be engaged energetically in public education through public lectures, films and videos, online tools, and popular articles.More technically, Prof. Kamionkowski will explore models for dark energy inspired by the string axiverse. These dark-energy models often involve not only axion-like quintessence fields but also other fields that may have small but subtle dynamical effects in the early Universe. Prof. Kamionkowski will explore a suite of techniques based on measurements from the cosmic microwave background (CMB) and galaxy surveys, as well as assorted searches for axion-like fields, to search for evidence of these dark-energy models. Kamionkowski also plans to study new ideas for dark matter. The implications of these limits for direct and indirect detection and the implications for CMB fluctuations, CMB spectral distortions, and 21-cm fluctuations from the dark ages will be explored. Prof. Kaplan plans to explore new approaches to the hierarchy problem in which a scalar field tunnels between vacua, thereby exploring a vast range of values for the Higgs mass. The convergence of the scanning to our Higgs mass is a consequence of a back reaction due to the scanning of negative as well as positive mass-squared. Prof. Kaplan will also develop a tree-level model of flavor of the Froggatt-Nielsen variety which could reproduce the Standard-Model fermion spectrum and would make predictions for flavor-changing neutral currents at future b-quark factories or tests of lepton-flavor violation. In addition to the training of students, numerous Broader Impacts of this project are envisioned. Kaplan will tell additional stories of particle physics with remnant footage from his recent film, "Particle Fever"; serve as advisor to several other science films and TV shows; and prepare a set of brief online physics tutorials. Kamionkowski will remain active as a public spokesperson for CMB science, do editorial work for prominent science journals, and serve on several advisory committees. Both Kamionkowski and Kaplan participate in the Johns Hopkins Quarknet program which engages Baltimore-area high-school teachers and students in cutting edge research.