CLASSIFICATION OF FLAT VIRTUAL PURE TANGLES

Abstract

Virtual knot theory, introduced by Kauffman [Virtual Knot theory, European J. Combin.20 (1999) 663–690, arXiv:math.GT/9811028], is a generalization of classical knot theory of interest because its finite-type invariant theory is potentially a topological interpretation [D. Bar-Natan, u, v, w-knots: Topology, Combinatorics and low and high algebra] of Etingof and Kazhdan's theory of quantization of Lie bi-algebras [Quantization of Lie Bialgebras, I, Selecta Math. (N.S.) 2 (1996) 1–41, arXiv:q-alg/9506005]. Classical knots inject into virtual knots [G. Kuperberg, What is Virtual Link? Algebr. Geom. Topol.3 (2003) 587–591, arXiv:math.GT/0208039], and flat virtual knots [V. O. Manturov, On free knots, preprint (2009), arXiv:0901.2214; On free knots and links, preprint (2009), arXiv:0902.0127] is the quotient of virtual knots which equates the real positive and negative crossings, and in this sense is complementary to classical knot theory within virtual knot theory. We completely classify flat virtual tangles with no closed components (pure tangles). This classification can be used as an invariant on virtual pure tangles and virtual braids.