5 research outputs found
Four-dimensional Fano toric complete intersections
We find at least 527 new four-dimensional Fano manifolds, each of which is a complete intersection in a smooth toric Fano manifold
Matter and singularities
We analyze the structure of matter representations arising from codimension
two singularities in F-theory, focusing on gauge groups SU(N). We give a
detailed local description of the geometry associated with several types of
singularities and the associated matter representations. We also construct
global F-theory models for 6D and 4D theories containing these matter
representations. The codimension two singularities encountered include examples
where the apparent Kodaira singularity type does not need to be completely
resolved to produce a smooth Calabi-Yau, examples with rank enhancement by more
than one, and examples where the 7-brane configuration is singular. We identify
novel phase transitions, in some of which the gauge group remains fixed but the
singularity type and associated matter content change along a continuous family
of theories. Global analysis of 6D theories on P^2 with 7-branes wrapped on
curves of small degree reproduces the range of 6D supergravity theories
identified through anomaly cancellation and other consistency conditions.
Analogous 4D models are constructed through global F-theory compactifications
on P^3, and have a similar pattern of SU(N) matter content. This leads to a
constraint on the matter content of a limited class of 4D supergravity theories
containing SU(N) as a local factor of the gauge group.Comment: 55 pages, 7 figures; v2: references added; v3: minor correctio