Mathematics Colloquia and Seminars
New Invariants of Spatial GraphsGeometry/Topology
|Speaker:||Erica Flapan, Pomona College|
|Start time:||Tue, Feb 26 2019, 1:30PM|
We introduce invariants of graphs embedded in \( S^3 \) which are related to the Wu invariant and the Simon invariant. Then we use our invariants to prove that \( K_7 \), all Möbius ladders with an odd number of rungs, and the Heawood graph are intrinsically chiral in \( S^3 \). We also use our invariants to obtain lower bounds for the minimal crossing number of particular embeddings of graphs in \( S^3 \).