The Lie bialgebra of loops on surfaces of Goldman and Turaev
نویسنده
چکیده
The coproduct is given by summing over self-intersections and removing the intersection point, and smoothing to obtain two paths. Precisely, let ∩α denote the set of self-intersections of α (assuming α is in general position). The coproduct is then given by summing over selfintersections and removing the intersection point, and smoothing to obtain two paths. Then δ(〈α〉) = ∑ q∈∩α 〈α1 q〉 ∧ 〈α2 q〉 (a ∧ b := a⊗ b− b⊗ a) (0.2)
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