Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: $\mathbb{G}_a^3$-structures on del Pezzo fibrations   In this paper we prove that del Pezzo fibrations admit
$\mathbb{G}_{a}^{3}$-structures if and only if they are $\mathbb{P}^2$-bundles
over $\mathbb{P}^{1}$.

12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ