Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cohomological dimension and Schreier's formula in Galois cohomology   Let p be a prime and F a field containing a primitive pth root of unity. Then
for n in N, the cohomological dimension of the maximal pro-p-quotient G of the
absolute Galois group of F is <=n if and only if the corestriction maps
H^n(H,Fp) -> H^n(G,Fp) are surjective for all open subgroups H of index p.
Using this result we derive a surprising generalization to dim_Fp H^n(H,Fp) of
Schreier's formula for dim_Fp H^1(H,Fp).

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The categories of this paper are: cond-mat
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The categories of this paper are: hep-ex
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The categories of this paper are: solv-int
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The categories of this paper are: funct-an
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The categories of this paper are: supr-con
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The categories of this paper are: physics
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The categories of this paper are: astro-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: gr-qc
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: nlin