Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Local existence in a class of characteristic problems for the Einstein
  vacuum equations   This paper has been withdrawn by the author due to an error in the use of the
Cauchy-Kowalevski theorem in section 4., theorem 4.1 which does not allow to
prove the final result. When (and if) this error will be cured it will be
replaced by a corrected version of the result.

8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph