Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Halphen pencils on quartic threefolds   For every smooth quartic threefold, we classify all pencils on it whose
general element is an irreducible surface birational to a smooth surface of
Kodaira dimension zero.

26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn