Grant N. Remmen

Hertz Fellow: Grant N. Remmen

University of Minnesota, Minneapolis

Area of Study

Physics, Astrophysics, Mathematics

Fellowship Years

2012 - present

Grant Remmen is a PhD candidate at the California Institute of Technology (Caltech), Burke Institute for Theoretical Physics. At Caltech, Grant has been conducting research on high-energy aspects of gravity and cosmology. With Professor Sean Carroll of Caltech’s Moore Center for Theoretical Cosmology and Physics, Grant solved a classic problem regarding the classical phase-space measure for the theory of cosmic inflation and applied this formalism to compute the expected amount of expansion in competing inflation models, allowing observation to better constrain theory. In addition, Grant and Dr. Carroll are disproving the theory of entropic, thermodynamically-emergent gravity. What's more, in recent work Grant and his collaborators have investigated a proposition for emergent spacetime described by the AdS/MERA (Anti-de Sitter – Multi-scale Entanglement Renormalization Ansatz) correspondence.In addition, with Professor Cliff Cheung, Grant has been placing bounds on the set of possible laws for high-energy particle physics. Grant and Dr. Cheung showed that there is a surprising conflict between the naturalness principle in quantum field theory and the Weak Gravity Conjecture (WGC), a quantum gravity condition on gauge theories related to black hole decay. In particular, their work may have important implications for the famous Hierarchy Problem in the Standard Model of particle physics. In 2014, Grant spoke about this research at the 20th International Symposium on Particles, Strings and Cosmology (PASCOS) in Warsaw, Poland. In other work, Grant and Dr. Cheung developed proofs of WGC-like bounds from unitarity, analyticity, and causality in the low-energy effective field theory of photons and gravitons. Currently, Grant and Dr. Cheung are using related mathematical techniques to constrain quantum gravitational corrections to the Einstein equations.

As an undergraduate, Grant made contributions across several diverse areas of physics and astrophysics, including relativistic orbital dynamics, with Professor Kinwah Wu, Mullard Space Science Lab, University College London, and Hubble Space Telescope Spectroscopy of Eta Carinae, with Dr. Kris Davidson, University of Minnesota. For his work in Galactic dark matter, Grant received the Chambliss Medal for exemplary student research from the American Astronomical Society in 2011. A U.S. Presidential Scholar, Goldwater Scholar, and National Science Foundation Graduate Research Fellow, Grant graduated, summa cum laude, with high distinction as a triple major in physics, astrophysics, and mathematics from the University of Minnesota in 2012.

After concluding his graduate studies, Grant plans to pursue a career in academic research, allowing him to investigate solutions to the most important and fundamental problems in theoretical physics, with applications to astrophysics and cosmology: dark matter, dark energy, quantum gravity, black holes, etc. He aims also to serve as an ambassador for science among America’s civic leaders and the public, while mentoring the next generation of scientists, and hopes that his work will kindle awareness and interest in the physical sciences.