Seminar talk, 9 December 2015

Speaker: Valentin Lychagin

Title: Invariants of projective $PSL_{2}$-actions and their application to recognition of fingerprints

Abstract:
We study the field of rational differential invariants of the left $PSL_{2}(\mathbb {R} )$-action on the homogeneous space $\mathrm {Diff} (S^{1})/PSL_{2}(\mathbb {R} )$ and use them to give an alternative description of the shape space and fingerprints, introduced by Mumford and Sharon.