Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum gravity effects on space-time   General relativity promotes space-time to a physical, dynamical object
subject to equations of motion. Quantum gravity, accordingly, must provide a
quantum framework for space-time, applicable on the smallest distance scales.
Just like generic states in quantum mechanics, quantum space-time structures
may be highly counter-intuitive. But if low-energy effects can be extracted,
they shed considerable light on the implications to be expected for a dynamical
quantum space-time. Loop quantum gravity has provided several such effects, but
even in the symmetry-reduced setting of loop quantum cosmology no complete
picture of effective space-time geometries describing especially the regime
near the big bang has been obtained. The overall situation regarding space-time
structures and cosmology is reviewed here, with an emphasis on the role of
dynamical states, effective equations, and general covariance.

7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
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The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys