Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Plebanski action extended to a unification of gravity and Yang-Mills
  theory   We study a unification of gravity with Yang-Mills fields based on a simple
extension of the Plebanski action to a Lie group G which contains the local
lorentz group. The Coleman-Mandula theorem is avoided because the theory has no
global spacetime symmetry. This may be applied to Lisi's proposal of an E8
unified theory, giving a fully E8 invariant action. The extended form of the
Plebanski action suggests a new class of spin foam models.

6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
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The categories of this paper are: funct-an
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The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph