Mordell-Weil torsion and the global structure of gauge groups in F-theory

We study the global structure of the gauge group $G$ of F-theory compactified on an elliptic fibration $Y$. The global properties of $G$ are encoded in the torsion subgroup of the Mordell-Weil group of rational sections of $Y$. Generalising the Shioda map to torsional sections we construct a specifi...

Full description

Saved in:
Bibliographic Details
Main Authors: Mayrhofer, Christoph (Author) , Till, Oskar (Author) , Weigand, Timo (Author)
Format: Article (Journal) Chapter/Article
Language:English
Published: 2014
In: Arxiv

Online Access:Verlag, kostenfrei, Volltext: http://arxiv.org/abs/1405.3656
Get full text
Author Notes:Christoph Mayrhofer, David R. Morrison, Oskar Till and Timo Weigand
Description
Summary:We study the global structure of the gauge group $G$ of F-theory compactified on an elliptic fibration $Y$. The global properties of $G$ are encoded in the torsion subgroup of the Mordell-Weil group of rational sections of $Y$. Generalising the Shioda map to torsional sections we construct a specific integer divisor class on $Y$ as a fractional linear combination of the resolution divisors associated with the Cartan subalgebra of $G$. This divisor class can be interpreted as an element of the refined coweight lattice of the gauge group. As a result, the spectrum of admissible matter representations is strongly constrained and the gauge group is non-simply connected. We exemplify our results by a detailed analysis of the general elliptic fibration with Mordell-Weil group $\mathbb Z_2$ and $\mathbb Z_3$ as well as a further specialization to $\mathbb Z \oplus \mathbb Z_2$. Our analysis exploits the representation of these fibrations as hypersurfaces in toric geometry.
Item Description:Gesehen am 19.12.2017
Physical Description:Online Resource