Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Theories with limited extrinsic curvature and a nonsingular anisotropic
  universe   We propose a class of theories that can limit scalars constructed from the
extrinsic curvature. Applied to cosmology, this framework allows us to control
not only the Hubble parameter but also anisotropies without the problem of
Ostrogradsky ghost, which is in sharp contrast to the case of limiting
spacetime curvature scalars. Our theory can be viewed as a generalization of
mimetic and cuscuton theories (thus clarifying their relation), which are known
to possess a structure that limits only the Hubble parameter on homogeneous and
isotropic backgrounds. As an application of our framework, we construct a model
where both anisotropies and the Hubble parameter are kept finite at any stage
in the evolution of the universe in the diagonal Bianchi type I setup. The
universe starts from a constant-anisotropy phase and recovers Einstein gravity
at low energies. We also show that the cosmological solution is stable against
a wide class of perturbation wavenumbers, though instabilities may remain for
arbitrary initial conditions.

3
The categories of this paper are: physics
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ