Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Vertex Formalism for Local Ruled Surfaces   We develop a vertex formalism for topological string amplitudes on ruled
surfaces with an arbitrary number of reducible fibers embedded in a Calabi-Yau
threefold. Our construction is based on large N duality and localization with
respect to a degenerate torus action. We also discuss potential generalizations
of our formalism to a broader class of Calabi-Yau threefolds using the same
underlying principles.

15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org