Research in High Energy Physics and Cosmology

This award funds the research activities of Professor Matthew B. Kleban at New York University.

There is strong observational evidence in cosmology that the expansion of our universe is accelerating at a slow rate, and that the very early universe underwent a period of extremely rapid accelerated expansion. At the same time, several theoretical constraints on cosmic acceleration have recently been proposed that are in sharp tension with these observations.

How can these mysterious features in the expansion history of the universe be explained? A breakthrough in understanding the meaning of these profound discoveries would promote the progress of science and advance the national interest by potentially revealing new laws of nature and helping to explain the origin and fate of our universe. This award will fund the research of Professor Matthew Kleban into theories of hypothetical particles called axions that could address these questions.

In addition, it will support his investigations of the physics of statistical models that can describe both the far future of a universe undergoing accelerated expansion and the surfaces of materials undergoing phase transitions. Lastly, it will enable him to continue his work on the quantum-mechanical physics of black holes and their formation and evaporation.

Professor Kleban's work will also have a broad impact in the form of public lectures and interviews, and in inspiring and training undergraduate and graduate physics students at NYU, as well as post-doctoral researchers and early-career scientists.

More technically, Professor Kleban will study the theory of multi-axion landscapes and their applications to cosmology, making use of the novel techniques he developed to push forward our understanding of such theories and of inflation in general. He will continue his work on the Brownian Loop Soup, building on a recent breakthrough in a connection to the O(n) model and the set of exact correlation functions and spectral information that were obtained as a result of that advance.

Finally, Professor Kleban will return to the topic of quantum black holes in anti-de Sitter spacetime, investigating the extent to which recently developed tools can be applied to higher-dimensional theories of gravity.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.