Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The World Function in Robertson-Walker Spacetime   A method for finding the world function of Robertson-Walker spacetimes is
presented. It is applied to find the world function for the $k=0, \ga=2$,
solution. The close point approximation for the Robertson-Walker world function
is calculated upto fourth order.

11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph