Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Classical limit for Dirac fermions with modified action in the presence
  of the black hole   We consider the model of Dirac fermions coupled to gravity as proposed in
\cite{VolovikBH}, in which superluminal velocities of particles are admitted.
In this model an extra term is added to the conventional Hamiltonian that
originates from Planck physics. Due to this term a closed Fermi surface is
formed in equilibrium inside the black hole. In this paper we propose the
covariant formulation of this model and analyse its classical limit. We
consider the dynamics of gravitational collapse. It appears that the Einstein
equations admit a solution identical to that of the ordinary general
relativity. Next, we consider motion of particles in the presence of the black
hole. Numerical solutions of the equations of motion are found which
demonstrate that the particles are able to escape from the black hole.

3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
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
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph