Padilla, Antonio: - Antonio Padilla is a leading theoretical physicist and cosmologist at the University of Nottingham. He is the Associate Director of the new Nottingham Centre of Gravity and has served as the chair of U.K. Cosmology for over a decade. In 2016, he and his collaborator shared the Buchalter Cosmology Prize for their work on the cosmological constant. He is also a star of the Numberphile YouTube network, where his most popular videos include a discussion of Ramanujan's sum of all positive integers, which has been viewed more than seven million times.