Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Alternative route towards the change of metric signature   Beginning with Hartle and Hawking's no-boundary proposal, it has long been
known that the pathology of a big bang singularity can be suppressed if a
transition into Riemannian (Euclidean) metric signature (the usual singularity
theorems become invalid in this region) occurs when we track back along cosmic
time. A vital component of this type of models, that needs to be clarified, is
the set of junction conditions at the boundary between the two signature
regimes. In the traditional approach, the signature change occurs in the
temporal sector through a switch of sign in the lapse-squared function.
Motivated by more straightforward connections with the big bang cosmology, we
explore here an alternative whereby the spatial metric eigenvalues change sign
instead, so that the Riemannian side is purely timelike. We investigate the
junction conditions required in this case.

0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph