Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The causal structure of Minkowski space time: possibilities and
  impossibilities of secure positioning
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
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int