Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Some Aspects of Virtual Black Holes   In this paper we shall consistently third quantize modified gravity. Then we
shall analyse certain aspects of virtual black holes in this third quantized
modified gravity. We will see how a statistical mechanical origin for the
Bekenstein-Hawking entropy naturally arises in this model. Furthermore, in this
model the area and thus the entropy of a real macroscopic black hole is
quantized. Virtual black holes cause loss of quantum coherence and this gives
an intrinsic entropy to all physical systems which can be used to define a
direction of time and hence provide a solution to the problem of time.

29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th