2017/03/22 by Conway, Anthony, Nagel, Matthias, Toffoli, Enrico · 1 citation
#57M25 #FOS: Mathematics #Geometric Topology (math.GT)
paper · doi:10.48550/arxiv.1703.07540
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.