Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: General fluctuations of the heterotic pure spinor string on curved
  backgrounds   The general fluctuations, in the form of vertex operators, for the heterotic
superstring in the pure spinor formalism are considered. The case of a flat
background is reviewed and the case of a curved case is studied. The
left-moving ghosts are pure spinors and the right-moving ghosts come from
fixing the reparametrization invariance. The role of the reparametrization
ghosts in the construction of the vertex operators is emphasized.

11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg