Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: RIP: The Macho Era (1974-2004)   This article reviews the life and death of a scientific theory.

24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
1
The categories of this paper are: cs
2
The categories of this paper are: math
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat