Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hidden Gravity in Open-String Field Theory   We clarify the nature of the graviton as a bound state in open-string field
theory: The flat metric in the action appears as the vacuum value of an OPEN
string field. The bound state appears as a composite field in the FREE field
theory.

35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn