ScalingStacks

We now verify that these three submodules are stable under d.d. For X2X_{2} this is obvious. To see it for X3X_{3}, notice that dz∈C¯(D1(∗11))[−2]{−2}dz\in\overline{C}(D_{1}(\ast 11))[-2]\{-2\} whenever z∈C¯(D1(∗11))[−2]{−2}.z\in\overline{C}(D_{1}(\ast 11))[-2]\{-2\}. Moreover, for such a z,z,

d​β​(z)=−d10(−1)​β​(z)+[−1]​ψ4​β​(z)=−d10(−1)​β​(z)+z=β​d11(−2)​(z)+zd\beta(z)=-d_{10}^{(-1)}\beta(z)+[-1]\psi_{4}\beta(z)=-d_{10}^{(-1)}\beta(z)+z=\beta d_{11}^{(-2)}(z)+z (111)

The second equality is implied by [−1]​ψ4​β=Id.[-1]\psi_{4}\beta=\mbox{Id}. Map ψ4​β\psi_{4}\beta is associated to the surface

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

Mikhail Khovanov

Original source: arXiv:math/9908171v2