Title: Anomalies and the Euler characteristic of elliptic Calabi–Yau threefolds
Abstract:We investigate the delicate interplay between the types of singular fibers in elliptic fibrations of Calabi-Yau threefolds (used to formulate F-theory) and the "matter" representation of the associate...We investigate the delicate interplay between the types of singular fibers in elliptic fibrations of Calabi-Yau threefolds (used to formulate F-theory) and the "matter" representation of the associated Lie algebra.The main tool is the analysis and the appropriate interpretation of the anomaly formula for six-dimensional supersymmetric theories.We find that this anomaly formula is geometrically captured by a relation among codimension two cycles on the base of the elliptic fibration, and that this relation holds for elliptic fibrations of any dimension.We introduce a "Tate cycle" that efficiently describes this relationship, and which is remarkably easy to calculate explicitly from the Weierstrass equation of the fibration.We check the anomaly cancellation formula in a number of situations and show how this formula constrains the geometry (and in particular the Euler characteristic) of the Calabi-Yau threefold.Read More