Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Hadamard condition on Robertson-Walker spacetime   Using construction of adiabatic vacuum states of a free scalar field on
Robertson-Walker spacetime, using results of Luders and Roberts we prove that
validity of the Hadamard condition implies smoothness of the scale factor.

31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph