Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Discrete fuzzy de Sitter cosmology   We analyze the spectrum of time observable in noncommutative cosmological
model introduced in [5], defined by $(\rho, s=\frac 12)\,$ representation of
the de Sitter group. We find that time has peculiar property: it is not
self-adjoint, but appropriate restrictions to the space of physical states give
self-adjoint extensions. Extensions have discrete spectrum with logarithmic
distribution of eigenvalues, $\,t_n \sim \ell\, \log\, n$+const, where $\ell$
characterizes noncommutativity and the usual assumption is
$\,\ell=\ell_{Planck}$. When calculated on physical states, radius of the
universe is bounded below by $\, \ell\, \sqrt{\frac 34\, \left( \frac 14
+\rho^2\right)}\, $, which resolves the big bang singularity. An immediate
consequence of the model is a specific breaking of the original symmetry at the
Planck scale.

37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
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The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th