Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 3+1 Formalism and Bases of Numerical Relativity   These lecture notes provide some introduction to the 3+1 formalism of general
relativity, which is the foundation of most modern numerical relativity. The
text is rather self-contained, with detailed calculations and numerous
examples. Contents: 1. Introduction, 2. Geometry of hypersurfaces, 3. Geometry
of foliations, 4. 3+1 decomposition of Einstein equation, 5. 3+1 equations for
matter and electromagnetic field, 6. Conformal decomposition, 7. Asymptotic
flatness and global quantities, 8. The initial data problem, 9. Choice of
foliation and spatial coordinates, 10. Evolution schemes.

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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
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The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
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The categories of this paper are: supr-con
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The categories of this paper are: alg-geom
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The categories of this paper are: chao-dyn
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The categories of this paper are: adap-org
3
The categories of this paper are: physics
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The categories of this paper are: atom-ph
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The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
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The categories of this paper are: cmp-lg