Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Homotopies in Grothendieck fibrations   We define a natural 2-categorical structure on the base category of a large
class of Grothendieck fibrations. Given any model category $\mathbf{C}$, we
apply this construction to a fibration whose fibers are the homotopy categories
of the slice categories $\mathbf{C}/A$, and we show that in the case
$\mathbf{C}=\mathbf{Top}$, our construction applied to this fibration recovers
the usual 2-category of spaces.

34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
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The categories of this paper are: alg-geom
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The categories of this paper are: q-alg
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The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
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The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
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The categories of this paper are: atom-ph