Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cosmological Time, Entropy and Infinity   Time is a parameter playing a central role in our most fundamental modelling
of natural laws. Relativity theory shows that the comparison of times measured
by different clocks depends on their relative motion and on the strength of the
gravitational field in which they are embedded. In standard cosmology, the time
parameter is the one measured by fundamental clocks (i.e., clocks at rest with
respect to the expanding space). This proper time is assumed to flow at a
constant rate throughout the whole history of the universe. We make the
alternative hypothesis that the rate at which the cosmological time flows
depends on the dynamical state of the universe. In thermodynamics, the arrow of
time is strongly related to the second law, which states that the entropy of an
isolated system will always increase with time or, at best, stay constant.
Hence, we assume that the time measured by fundamental clocks is proportional
to the entropy of the region of the universe that is causally connected to
them. Under that simple assumption, we find it possible to build toy
cosmological models that present an acceleration of their expansion without any
need for dark energy while being spatially closed and finite, avoiding the need
to deal with infinite values.

9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph