Singular Hecke algebras, Markov traces, and HOMFLY-type invariants
We define the singular Hecke algebra as the quotient of the singular braid monoid algebra by the Hecke relations , . We define the notion of Markov trace in this context, fixing the number of singular points, and we prove that a Markov trace determines an invariant on the links with singular points which satisfies some skein relation. Let denote the set of Markov traces with singular points. This is a -vector space. Our main result is that is of dimension . This result is completed...