Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A geometric solution to the coincidence problem, and the size of the
  landscape as the origin of hierarchy   Without assuming necessary conditions for observers such as galaxies or
entropy production, we show that the causal patch measure predicts the
coincidence of vacuum energy and present matter density. Their common scale,
and thus the enormous size of the visible universe, has its origin in the
number of metastable vacua in the landscape.

24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con