ScalingStacks

5.6. Pointed categories

Let 𝒱{\mathcal{V}} be a differential pointed category. A bimodule 22-represesentation on 𝒱{\mathcal{V}} is the data of a strict monoidal differential pointed functor from the 22-category with one object given by π’°βˆ™{\mathcal{U}}^{\bullet} to Bimodβˆ™\mathrm{Bimod}^{\bullet}. Note that a bimodule 22-representation on 𝒱{\mathcal{V}} gives rise to a bimodule 22-representation on k⁑[𝒱]k[{\mathcal{V}}].

A bimodule lax bi-22-representation is a lax differential pointed 22-functor Ξ₯:π’°βˆ™βˆ§π’°βˆ™β†’Bimodβˆ™\Upsilon:{\mathcal{U}}^{\bullet}\wedge{\mathcal{U}}^{\bullet}\to\mathrm{Bimod}^{\bullet}. We say it is a bimodule lax bi-22-representation on Ξ₯(βˆ—βˆ§βˆ—)\Upsilon(\ast\wedge\ast).

A bimodule lax bi-22-representation on 𝒱{\mathcal{V}} is the same as the data of

  • β€’

    (𝒱,𝒱)({\mathcal{V}},{\mathcal{V}})-bimodules Ei,jE_{i,j} for i,jβ‰₯0i,j\geq 0

  • β€’

    morphisms of differential pointed algebras Hi∧Hjβ†’End⁑(Ei,j)H_{i}\wedge H_{j}\to\operatorname{End}\nolimits(E_{i,j})

  • β€’

    morphisms ΞΌ(i,j),(iβ€²,jβ€²):Ei,j​Eiβ€²,jβ€²β†’Ei+iβ€²,j+jβ€²\mu_{(i,j),(i^{\prime},j^{\prime})}:E_{i,j}E_{i^{\prime},j^{\prime}}\to E_{i+i^{\prime},j+j^{\prime}} satisfying properties (1) and (2) of Β§4.2.1.

We define the differential pointed category Ξ”E​(𝒱)\Delta_{E}({\mathcal{V}}) as the quotient of T𝒱​(E0,1​E1,0)T_{{\mathcal{V}}}(E_{0,1}E_{1,0}) by the equivalence relation generated by f∼fβ€²f\sim f^{\prime} if (f,fβ€²)(f,f^{\prime}) is in the equalizer of a composition

(E0,1​E1,0)i​(c1,c2)β†’canEi,i​(c1,c2)β†’canEi,i​(c1,c2)/((Tr∧1)​x∼(1∧Tr)​x)x∈Ei,i, 1≀r<i.(E_{0,1}E_{1,0})^{i}(c_{1},c_{2})\xrightarrow{{\mathrm{can}}}E_{i,i}(c_{1},c_{2})\xrightarrow{{\mathrm{can}}}E_{i,i}(c_{1},c_{2})/((T_{r}\wedge 1)x\sim(1\wedge T_{r})x)_{x\in E_{i,i},\ 1\leq r<i}.

Consider a differential pointed category 𝒱{\mathcal{V}} endowed with two bimodule 22-representations (F1,Ο„1)(F_{1},\tau_{1}) and (E2,Ο„2)(E_{2},\tau_{2}) and a closed morphism Ξ»:F1​E2β†’E2​F1\lambda:F_{1}E_{2}\to E_{2}F_{1} such that the diagrams (4.2.1) commute.

We define the differential pointed category Δλ′​(𝒱)\Delta^{\prime}_{\lambda}({\mathcal{V}}) as the quotient of T𝒱​(F1​E2)T_{{\mathcal{V}}}(F_{1}E_{2}) by the equivalence relation generated by

(F1​λ​E2)∘(Ο„1​E22)​(f)∼(F1​λ​E2)∘(F12​τ2)​(f)​ for ​f∈F12​E22​(c1,c2)​ and ​c1,c2βˆˆπ’±.(F_{1}\lambda E_{2})\circ(\tau_{1}E_{2}^{2})(f)\sim(F_{1}\lambda E_{2})\circ(F_{1}^{2}\tau_{2})(f)\text{ for }f\in F_{1}^{2}E_{2}^{2}(c_{1},c_{2})\text{ and }c_{1},c_{2}\in{\mathcal{V}}.

We define the differential pointed category Δλ​(𝒱)\Delta_{\lambda}({\mathcal{V}}). We consider first the differential pointed category with same objects as 𝒱{\mathcal{V}} and pointed set of maps v1β†’v2v_{1}\to v_{2} given by ⋁iβ‰₯0E2i​F1i​(v1,v2)\bigvee_{i\geq 0}E_{2}^{i}F_{1}^{i}(v_{1},v_{2}). The category Δλ​(𝒱)\Delta_{\lambda}({\mathcal{V}}) is the quotient of that category by the equivalence relation generated by (Tr∧1)​(f)∼(1∧Tr)​(f)(T_{r}\wedge 1)(f)\sim(1\wedge T_{r})(f) for f∈E2i​F1if\in E_{2}^{i}F_{1}^{i} and 1≀r<i1\leq r<i.

Note that there is a canonical isomorphism of differential categories for ?∈{βˆ…,β€²}?\in\{\emptyset,\prime\}

k⁑[Δλ?​(𝒱)]β†’βˆΌΞ”Ξ»?​(k⁑[𝒱])k[\Delta^{?}_{\lambda}({\mathcal{V}})]\mathrel{\mathop{\kern 0.0pt\to}\limits^{\sim}}\Delta^{?}_{\lambda}(k[{\mathcal{V}}])

Original mathematics by the credited authors. Source collection and HTML conversion remain in progress.

Andrew Manion, Raphael Rouquier

Original source: arXiv:2009.09627v2