On the computation of Hopf 2-cocycles with an example of diagonal type

@article{Iglesias2022OnTC,
  title={On the computation of Hopf 2-cocycles with an example of diagonal type},
  author={Agust'in Garc'ia Iglesias and Jos'e Ignacio S'anchez},
  journal={Glasgow Mathematical Journal},
  year={2022}
}
We present a framework for the computation of the Hopf 2-cocycles involved in the deformations of Nichols algebras over semisimple Hopf algebras. We write down a recurrence formula and investigate the extent of the connection with invariant Hochschild cohomology in terms of exponentials. As an example, we present detailed computations leading to the explicit description of the Hopf 2-cocycles involved in the deformations of a Nichols algebra of Cartan type $A_2$ with $q=-1… 

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