ScalingStacks

0NG2

Theorem 3.10. Consider four-manifolds W1⊆W2⊆W3⊆W4W_{1}\subseteq W_{2}\subseteq W_{3}\subseteq W_{4} where

  • •

    W1=♮m​(S1×B3)W_{1}=\natural^{m}(S^{1}\times B^{3}) is the union of mm 1-handles;

  • •

    W2W_{2} is obtained from W1W_{1} by attaching nn two-handles along a framed link KK;

  • •

    W3W_{3} is obtained from W2W_{2} by attaching pp three-handles along spheres S1,…​SpS_{1},\dots S_{p};

  • •

    W4W_{4} is obtained from W3W_{3} by attaching some four-handles.

Consider also a framed link L⊂∂W4L\subset\partial W_{4}. We represent W4W_{4} by a Kirby diagram, viewing K∪LK\cup L as a link in ∂W1\partial W_{1}, and the spheres SiS_{i} in terms of surfaces Σj\Sigma_{j} on ∂W1\partial W_{1} with ∂Σj\partial\Sigma_{j} consisting of some copies of various components of KK (so that SjS_{j} is the union of Σj\Sigma_{j} and the corresponding cores of the 2-handles).

Given

α′∈H2L​(W4,ℤ)≅H2L​(W3,ℤ)≅H2L​(W2,ℤ)/([S1],…,[Sp]),\alpha^{\prime}\in H_{2}^{L}(W_{4};{\mathbb{Z}})\cong H_{2}^{L}(W_{3};{\mathbb{Z}})\cong H_{2}^{L}(W_{2};{\mathbb{Z}})/([S_{1}],\dots,[S_{p}]),

let ⟨α′⟩\langle\alpha^{\prime}\rangle be the set of all α∈H2L​(W2,ℤ)⊆ℤn\alpha\in H_{2}^{L}(W_{2};{\mathbb{Z}})\subseteq{\mathbb{Z}}^{n} whose equivalence class modulo ([S1],…,[Sp])([S_{1}],\dots,[S_{p}]) is α′\alpha^{\prime}.

Then, the skein lasagna module 𝒮0N​(W4,L,α′)\mathcal{S}_{0}^{N}(W_{4};L,\alpha^{\prime}) is isomorphic to the quotient of the direct sum of cabled skein lasagna modules ⨁α∈⟨α′⟩𝒮¯0N,α​(W1,K,L)\bigoplus_{\alpha\in\langle\alpha^{\prime}\rangle}\underline{\mathcal{S}\mkern-3.0mu}\mkern 3.0mu_{0}^{N,\alpha}(W_{1};K,L) by the relations

(14) Ψ¯I×∂W1;Σj(n∙),α′(v)=0,n=0,1,…,N−2,\underline{\Psi}_{I\times\partial W_{1};\Sigma_{j}(n\bullet),\alpha^{\prime}}(v)=0,\ \ n=0,1,\dots,N-2,

and

(15) Ψ¯I×∂W1;Σj((N−1)∙),α′(v)=v\underline{\Psi}_{I\times\partial W_{1};\Sigma_{j}((N-1)\bullet),\alpha^{\prime}}(v)=v

for all v∈⨁α∈⟨α′⟩𝒮¯0N,α​(W1,K,L)v\in\bigoplus_{\alpha\in\langle\alpha^{\prime}\rangle}\underline{\mathcal{S}\mkern-3.0mu}\mkern 3.0mu_{0}^{N,\alpha}(W_{1};K,L) and j=1,…,pj=1,\dots,p.

0NG3

Proof. First, note that the addition of 4-handles does not affect the skein lasagna module, in view of Proposition 3.4. Thus, we can consider W3W_{3} instead of W4W_{4}.

The skein lasagna module of LL viewed in the boundary of ∂W\partial W is given by 𝒮¯0N,α​(W1,K,L)\underline{\mathcal{S}\mkern-3.0mu}\mkern 3.0mu_{0}^{N,\alpha}(W_{1};K,L) according to Theorem 3.2. When we add a 3-handle, we divide by the relations

(16) ΨI×Y;Δ+,α′​(v⊗Xn)=ΨI×Y;Δ−,α′​(v⊗Xn),\Psi_{I\times Y;\Delta_{+},\alpha^{\prime}}(v\otimes X^{n})=\Psi_{I\times Y;\Delta_{-},\alpha^{\prime}}(v\otimes X^{n}),

as proved in Theorem 3.7. In terms of the identifications Φ\Phi from Theorem 3.2, the left hand side of (16) is given by Equation (11), and the right hand side by Equation (13). We thus get relations of the form (14) and (15). The generalization to multiple 3-handles is straightforward. ∎

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

Ciprian Manolescu, Kevin Walker, Paul Wedrich

Original source: arXiv:2206.04616v2