Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Symmetric-Bounce Quantum State of the Universe   A proposal is made for the quantum state of the universe that has an initial
state that is macroscopically time symmetric about a homogeneous, isotropic
bounce of extremal volume and that at that bounce is microscopically in the
ground state for inhomogeneous and/or anisotropic perturbation modes. The
coarse-grained entropy is minimum at the bounce and then grows during inflation
as the modes become excited away from the bounce and interact (assuming the
presence of an inflaton, and in the part of the quantum state in which the
inflaton is initially large enough to drive inflation). The part of this pure
quantum state that dominates for observations is well approximated by quantum
processes occurring within a Lorentzian expanding macroscopic universe. Because
this part of the quantum state has no negative Euclidean action, one can avoid
the early-time Boltzmann brains and Boltzmann solar systems that appear to
dominate observations in the Hartle-Hawking no-boundary wavefunction.

2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org