Sections, multisections, and U(1) fields in F-theory
Sections, multisections, and U(1) fields in F-theory
We show that genus-one fibrations lacking a global section fit naturally into the geometric moduli space of Weierstrass models.Elliptic fibrations with multiple sections (nonzero Mordell-Weil rank), which give rise in F-theory to abelian U (1) fields, arise as a subspace of the set of genus-one fibrations with multisections.Higgsing of certain …