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Strong Haken via Sphere Complexes

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 Added by Sebastian Hensel
 Publication date 2021
  fields
and research's language is English




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We give a short proof of Scharlemanns Strong Haken Theorem for closed $3$-manifolds (and manifolds with spherical boundary). As an application, we also show that given a decomposing sphere $R$ for a $3$-manifold $M$ that splits off an $S^2 times S^1$ summand, any Heegaard splitting of $M$ restricts to the standard Heegaard splitting on the summand.

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