String Theory seminars

Benjamin Safdi studies the axion mass constraints obtained when grand unification and string theory are considered together with the QCD axion. Unitarity reasoning and explicit string compactifications, including examples from the Kreuzer–Skarke type-IIB ensemble, favor masses between 10^-11 and 10^-8 electronvolts. The talk explains how these theoretical frameworks combine to restrict a candidate extension of the Standard Model.