Quandle polynomial;
singular knots and links;
singquandle polynomial;
D O I:
10.4153/S0008439521000837
中图分类号:
O1 [数学];
学科分类号:
0701 ;
070101 ;
摘要:
We introduce shadow structures for singular knot theory. Precisely, we define two invariants of singular knots and links. First, we introduce a notion of action of a singquandle on a set to define a shadow counting invariant of singular links which generalize the classical shadow colorings of knots by quandles. We then define a shadow polynomial invariant for shadow structures. Lastly, we enhance the shadow counting invariant by combining both the shadow counting invariant and the shadow polynomial invariant. Explicit examples of computations are given.