4 votes
Accepted

Does $U_q (\mathfrak{sl}_2)$ have a universal $R$-matrix?

$U_q(\mathfrak{sl}_2)$ is indeed not quasitriangular with the usual $R$-matrix. Instead it satisfies a weaker condition of being braided [1]. One can certainly show that the usual universal R-matrix ...
Calvin McPhail-Snyder's user avatar
4 votes

Is there an "arithmetic cobordism category"?

Unfortunately, I think we're still quite far away from knowing the answer to your question. Fortunately, a lot of progress has been made without answering your question. The key advance here was ...
NZK's user avatar
  • 345

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