Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Making the hyper--K\"ahler structure of N=2 quantum string manifest   We show that the Lorentz covariant formulation of N=2 string in a curved
space reveals an explicit hyper--K\"ahler structure. Apart from the metric, the
superconformal currents couple to a background two--form. By superconformal
symmetry the latter is constrained to be holomorphic and covariantly constant
and allows one to construct three complex structures obeying a
(pseudo)quaternion algebra.

17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex