Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Proposal for the Quantum Theory of Gravity   We propose a model for the quantum theory of gravity. the model has
diffeomorphism invariance, a natural length scale, and (plausibly) propagating
modes. in the new addendum, we alter the model in a way which makes the
propagating modes much easier to approach.

30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga