Particle and Quantum Field Theory Investigations

New York University, New York NY

Investigators

Abstract

This award funds the research activities of Professors G. Gabadadze, M. Porrati, and A. Sirlin at New York University. Members of this research group work towards solving fundamental questions in elementary particle physics, cosmology, and gravitation. The research interests of these faculty members are complementary to one another. To discover new physics it is essential to master the theory that describes all known elementary interactions excluding gravity, namely the so-called Standard Model. This is the aim of Prof. Sirlin's research. Quantum gravity and supergravity are the focus of Prof. Porrati's research. These are the theories most relevant in the study of the universe as a whole, i.e. at very large distances, or for understanding the very early universe. The study of quantum gravity also connects with attempts to understand the nature of dark matter and dark energy --- mysterious forms of matter and energy which are critical for understanding the way in which the universe evolves. These problems are investigated by Profs. Porrati and Gabadadze. Thus, research in this area advances the national interest by promoting the progress of science in one of its most fundamental directions: the discovery and understanding of new physical laws. Broader impacts are also expected from the project. All senior investigators carry out their research in close collaboration with graduate students and postdocs, who are thus trained in advanced theoretical research. Dissemination of research results will occur through review articles to be published in specialized and popular-science journals as well as through the organization of workshops, video- and Internet-based courses, and popular lectures. More specifically, Porrati plans to study topology-changing transition amplitudes in pure AdS3 gravity as well as the torus partition function and certain indices for pure 3D gravity and supergravity in various formulations. He also plans to study a generalization of matter couplings in certain supergravity models of inflation containing higher powers of the scalar curvature. Properties of high-spin particles in interaction in AdS and Minkowski backgrounds will be studied by Porrati continuing work done in the last years. Porrati also plans to study holographic renormalization flows of 2D conformal field theories with different left and right central charges, using a recently discovered new theory of AdS3 massive gravity called "minimal massive gravity." Gabadadze is proposing research in several different directions --- on the cosmological constant problem and modified gravity, on the AdS/CFT correspondence for massive gravity, on quantum liquids in dwarf stars, and on solitons in cold atom systems --- all using the method of effective quantum field theory as a unifying theme. Finally, in view of the increased precision of a 2013 measurement reported by the MuCap Collaboration, Sirlin plans to update and improve his 2007 analysis. In particular, he plans to study the possibility that further improvement in the experimental precision may lead to an independent, accurate value for the axial-vector coupling $g_{A}$, a result that may have important implications for neutron beta decay. Sirlin also plans to study the radiative corrections to antineutrino capture by protons, a process that is currently important for reactor studies of neutrino oscillations.