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Infinity of the τ-invariant under dual-cone boundary vanishing for Maslov-zero tori

Show that if L ⊂ M is a Maslov 0 Lagrangian torus and the boundary of the dual cone C^*(L,M) satisfies ∂(C^*(L,M)) = {0}, then the τ-invariant associated to L equals infinity; that is, prove τ(L) = ∞.

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Background

The τ-invariant, defined as the valuation of the leading deformation differential d_def in the special deformation retraction model, measures the size of ambient deformation of SC*_M(D) relative to the intrinsic theory. Earlier, Theorem \ref{tmTauConstant} shows spectral sequence degeneration when the dual cone C*(D,M) projects trivially under the boundary map, in exact contexts.

The conjecture proposes removing exactness assumptions, positing that for Maslov 0 Lagrangian tori L with ∂(C*(L,M)) = {0}, one should have τ(L) = ∞. This would imply that ambient symplectic cohomology is undeformed relative to intrinsic models around such tori, significantly strengthening the local-to-global reconstruction framework in SYZ mirror symmetry.

A proof would extend ambient–intrinsic degeneracy criteria beyond exact or aspherical settings and reinforce the role of flux-based cone conditions in controlling deformations.

References

Conjecture. If L⊂ M is a Maslov 0 Lagrangian torus with ∂(C*(L,M))={0}, then τ(L)=∞.

Boundary Depth and Deformations of Symplectic Cohomology (2510.17607 - Groman, 20 Oct 2025) in Subsection ‘Collapse in SYZ Mirror Symmetry’ (\ref{subsec:collapse}), Conjecture \ref{ConjTauInfinite}