Knot soliton in Weinberg-Salam model

We study numerically the topological knot solution suggested recently in the Weinberg-Salam model. Applying the SU(2) gauge-invariant Abelian projection we demonstrate that the restricted part of the Weinberg-Salam Lagrangian containing the interaction of the neutral boson with the Higgs scalar can be reduced to the Ginzburg-Landau model with the hidden SU(2) symmetry. The energy of the knot composed from the neutral boson and Higgs field has been evaluated by using the variational method with a modified Ward ansatz. The obtained numerical value is 39 TeV which provides the upper bound on the electroweak knot energy.