Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: New F-theory lifts II: Permutation orientifolds and enhanced
  singularities   In this paper, a procedure is developed to construct compact F-theory
fourfolds corresponding to perturbative IIB O7/O3 models on CICY threefolds
with permutation involutions. The method is explained in generality, and then
applied to specific examples where the involution permutes two Del Pezzo
surfaces. The fourfold construction is successfully tested by comparing the D3
charges predicted by F-theory and IIB string theory. The constructed smooth
fourfolds are then taken to the locus in moduli space where they have enhanced
SU(5) singularities. A general, intuitive method is developed for engineering
the desired singularities in Weierstrass models for complicated D7-brane
setups.

5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs