ScalingStacks

Using the splitting (89) of VD2V_{D_{2}} and Lemma 1, we can decompose the ℐ′\mathcal{I}^{\prime}-cube VD1V_{D_{1}} as a direct sum of two ℐ′\mathcal{I}^{\prime}-cubes as follows:

VD1=V′⊕V′′V_{D_{1}}=V^{\prime}\oplus V^{\prime\prime} (95)

where

V′(∗0)\displaystyle V^{\prime}(\ast 0) =\displaystyle= 0\displaystyle 0 (96)
V′(∗1)\displaystyle V^{\prime}(\ast 1) =\displaystyle= ℵ(VD){−1}⊂VD2{−1}=VD1(∗1)\displaystyle\aleph(V_{D})\{-1\}\subset V_{D_{2}}\{-1\}=V_{D_{1}}(\ast 1) (97)
V′′(∗0)\displaystyle V^{\prime\prime}(\ast 0) =\displaystyle= VD=VD1(∗0)\displaystyle V_{D}=V_{D_{1}}(\ast 0) (98)
V′′(∗1)\displaystyle V^{\prime\prime}(\ast 1) =\displaystyle= Δa(VD){−1}⊂VD2{−1}=VD1(∗1)\displaystyle\Delta_{a}(V_{D})\{-1\}\subset V_{D_{2}}\{-1\}=V_{D_{1}}(\ast 1) (99)

Tensoring (95) with Eℐ′E_{\mathcal{I}^{\prime}} we get a splitting of skew-commutative ℐ′\mathcal{I}^{\prime}-cubes

VD1⊗Eℐ′=(V′⊗Eℐ′)⊕(V′′⊗Eℐ′)V_{D_{1}}\otimes E_{\mathcal{I}^{\prime}}=(V^{\prime}\otimes E_{\mathcal{I}^{\prime}})\oplus(V^{\prime\prime}\otimes E_{\mathcal{I}^{\prime}}) (100)

This induces a splitting of complexes associated to these skew ℐ′\mathcal{I}^{\prime}-cubes

C¯​(VD1⊗Eℐ′)=C¯​(V′⊗Eℐ′)⊕C¯​(V′′⊗Eℐ′)\overline{C}(V_{D_{1}}\otimes E_{\mathcal{I}^{\prime}})=\overline{C}(V^{\prime}\otimes E_{\mathcal{I}^{\prime}})\oplus\overline{C}(V^{\prime\prime}\otimes E_{\mathcal{I}^{\prime}}) (101)

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

Mikhail Khovanov

Original source: arXiv:math/9908171v2