Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Beyond the Friedmann-Lemaitre-Robertson-Walker Big Bang singularity   Einstein's equation, in its standard form, breaks down at the Big Bang
singularity. A new version, equivalent to Einstein's whenever the latter is
defined, but applicable in wider situations, is proposed. The new equation
remains smooth at the Big Bang singularity of the
Friedmann-Lemaitre-Robertson-Walker model. It is a tensor equation defined in
terms of the Ricci part of the Riemann curvature. It is obtained by taking the
Kulkarni-Nomizu product between Einstein's equation and the metric tensor.

10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat