Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Differential Forms, Hopf Algebra and General Relativity I   We review the language of differential forms and their applications to
Riemannian Geometry with an orientation to General Relativity. Working with the
principal algebraic and differential operations on forms, we obtain the
structure equations and their symmetries in terms of a new product (the
co-multiplication). It is showen how the Cartan - Grassmann algebra can be
endowed with the structure of a Hopf algebra.

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The categories of this paper are: acc-phys
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The categories of this paper are: physics
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
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The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: chem-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
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The categories of this paper are: math
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The categories of this paper are: q-alg
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-th