Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Associative algebra deformations of the Connes-Moscovici's Hopf algebra
  $\mathcal{H}_1$   We compute the second Hochschild cohomology space $HH^2(\mathcal{H}_1)$ of
Connes-Moscovici's Hopf algebra $\mathcal{H}_1$, giving the infinitesimal
deformations (up to equivalence) of the associative structure.
  $HH^2(\mathcal{H}_1)$ is shown to be one dimensional, and thus
Connes-Moscovici's formal deformation of $\mathcal{H}_1$ using Rankin-Cohen
brackets is unique up to equivalence.

17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
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The categories of this paper are: stat
26
The categories of this paper are: bayes-an
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The categories of this paper are: nlin
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
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The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
19
The categories of this paper are: eess
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The categories of this paper are: patt-sol
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The categories of this paper are: mtrl-th
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The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat