Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Novel Edge States in Self-Dual Gravity   In contrast to the Einstein-Hilbert action, the action for self-dual gravity
contains vierbeins. They are eleminated at the level of observables by an
$SL(2,\mathbb{C})$ gauge condition implied by the action. We argue that despite
this condition, new "edge" or superselected state vectors corresponding to maps
of the spheres $S^2_{\infty}$ at infinity to $SL(2, \mathbb{C})$ arise. They
are characterised by new quantum numbers and they lead to mixed states. For
black holes, they arise both at the horizon and the spatial infinity and may be
relevant for the black hole information paradox. Similar comments can be made
about the Einstein-Palatini action which uses vierbeins.

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The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
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The categories of this paper are: eess
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
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The categories of this paper are: cmp-lg