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Multivariable signatures, genus bounds and $0.5$-solvable cobordisms

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 نشر من قبل Matthias Nagel
 تاريخ النشر 2017
  مجال البحث
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We refine prior bounds on how the multivariable signature and the nullity of a link change under link cobordisms. The formula generalizes a series of results about the 4-genus having their origins in the Murasugi-Tristram inequality, and at the same time extends previously known results about concordance invariance of the signature to a bigger set of allowed variables. Finally, we show that the multivariable signature and nullity are also invariant under $0.5$-solvable cobordism.



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