Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Universality of geometry   In models of emergent gravity the metric arises as the expectation value of
some collective field. Usually, many different collective fields with
appropriate tensor properties are candidates for a metric. Which collective
field describes the "physical geometry"? We resolve this "metric ambiguity" by
an investigation of the most general form of the quantum effective action for
several metrics. In the long-distance limit the physical metric is universal
and accounts for a massless graviton. Other degrees of freedom contained in the
various metric candidates describe very massive scalars and symmetric second
rank tensors. They only play a role at microscopic distances, typically around
the Planck length. The universality of geometry at long distances extends to
the vierbein and the connection. On the other hand, for distances and time
intervals of Planck size geometry looses its universal meaning. Time is born
with the big bang.

15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat