Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Note on Real Tunneling Geometries   In the Hartle-Hawking ``no boundary'' approach to quantum cosmology, a real
tunneling geometry is a configuration that represents a transition from a
compact Riemannian spacetime to a Lorentzian universe. I complete an earlier
proof that in three spacetime dimensions, such a transition is ``probable,'' in
the sense that the required Riemannian geometry yields a genuine maximum of the
semiclassical wave function.

18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci