English

On comparison of the Tamarkin and the twisted tensor product 2-operads

Quantum Algebra 2023-11-17 v2 Category Theory

Abstract

There are known two different constructions of contractible dg 2-operads, providing a weak 2-category structure on the following dg 2-quiver of small dg 2-categories. Its vertices are small dg 2-categories over a given field, arrows are dg functors, and the 2-arrows FGF\Rightarrow G are defined as the Hochschild cochains of CC with coefficients in CC-bimodule D(F(),G(=))D(F(-),G(=)), where F,G ⁣:CDF,G\colon C\to D are dg functors, C,DC,D small dg categories. It is known that such definition is correct homotopically, but, on the other hand, the corresponding dg 2-quiver fails to be a strict 2-category. The question ``What do dg categories form'' is the question of finding a weak 2-category structure on it, in an appropriate sense. One way of phrasing it out is to make it an algebra over a contractible 2-operad, in the sense of M.Batanin [Ba1,2] (in turn, there are many compositions of 2-arrows for a given diagram, but their totality forms a contractible complex) . In [T], D.Tamarkin proposed a contractible Δ\Delta-colored 2-operad in Sets, whose dg condensation solves the problem. In our recent paper arXiv:1807.04305 we constructed contractible dg 2-operad, called the twisted tensor product operad, acting on the same 2-quiver (the construction uses the twisted tensor product of small dg categories introduced in arXiv:1803.01191). In this paper, we compare the two constructions.

Keywords

Cite

@article{arxiv.2304.04132,
  title  = {On comparison of the Tamarkin and the twisted tensor product 2-operads},
  author = {Boris Shoikhet},
  journal= {arXiv preprint arXiv:2304.04132},
  year   = {2023}
}

Comments

v1 25 pages It is an improved and corrected version of Appendix B of the previous version of arXiv:1807.04305, which has been removed from the most recent version v2 (Nov 2023): 26 pages, 2-operadic whiskering map (Section 2) is fixed, misprints are corrected