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Symmetric unions without cosmetic crossing changes

Student-Run Geometry/Topology Seminar

Speaker: Allison Moore, UC Davis
Location: 1147 MSB
Start time: Wed, Sep 28 2016, 2:10PM

A classic problem in knot theory is the cosmetic crossing conjecture. This conjecture asserts that a crossing change will always change the knot type, unless the crossing is nugatory. In the main geometry seminar I'll describe an obstruction to so-called "cosmetic" crossing changes. In the student seminar, I'll show how to use that obstruction to produce new infinite families of knots for which the conjecture is true. In the process, we'll review branched double covers, L-spaces, and discuss some computational techniques which arise in various homology theories.