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arXiv · 2506.06110

On the parametrised Whitehead torsion of families of nearby Lagrangian submanifolds

Sylvain Courte·Noah Porcelli
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Abstract

Motivated by the strong nearby Lagrangian conjecture, we constrain the parametrised Whitehead torsion of a family of closed exact Lagrangian submanifolds in a cotangent bundle. We prove the parametrised Whitehead torsion admits a factorisation through simpler maps, in particular implying it is trivial on $π_0$, $π_1$, and that its image is divisible by the Euler characteristic. We provide concrete implications for the Lagrangian monodromy question in the case of a high dimensional torus. This generalises earlier work of Abouzaid and Kragh \cite{AbKr} on the $π_0$ version, using different methods. Our main tool is the theory of twisted generating functions, building on \cite{ACGK}.

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Sylvain Courte, Noah Porcelli. 2025-06-06. On the parametrised Whitehead torsion of families of nearby Lagrangian submanifolds. https://arxiv.org/abs/2506.06110

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