Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hartle-Hawking boundary conditions as Nucleation by de Sitter Vacuum   It is shown that, for a de Sitter Universe, the Hartle-Hawking (HH) wave
function can be obtained in a simple way starting from the
Friedmann-Lemaitre-Robertson-Walker (FLRW) line element of cosmological
equations. An oscillator having imaginary time is indeed derived starting from
the Hamiltonian obtaining the HH condition. This proposes again some crucial
matter on the meaning of complex time in cosmology. In order to overcome such
difficulties, we propose an interpretation of the HH framework based on de
Sitter Projective Holography.

35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci