We propose a new method of generalizing classical link invariants for the case of virtual links. In particular, we have generalized the knot quandle, the knot fundamental group, the Alexander module, and the coloring invariants. The virtual Alexander module leads to a definition of VA-polynomial that has no analogue in the classical case (i.e. vanishes on classical links).
机构:
Waseda Univ, Fac Sci & Engn, Dept Math, Shinjuku Ku, 3-4-1 Ohkubo, Tokyo 1698555, JapanWaseda Univ, Fac Sci & Engn, Dept Math, Shinjuku Ku, 3-4-1 Ohkubo, Tokyo 1698555, Japan