F-theory
formalism for describing nonperturbative compactifications of Type IIB string theory via Calabi–Yau manifolds admitting elliptic fibrations
en-US/ˈɛf - ˌθiəˌɹi/
en-GB/ɛf - θɪəɹiː/
formalism for describing nonperturbative compactifications of Type IIB string theory via Calabi–Yau manifolds admitting elliptic fibrations