  The structure of the flux-tube profile in Abelian-projected (AP) SU(2) gauge
theory in the maximally Abelian gauge is studied. The connection between the AP
flux tube and the classical flux-tube solution of the U(1) dual Abelian Higgs
(DAH) model is clarified in terms of the path-integral duality transformation.
This connection suggests that the electric photon and the magnetic monopole
parts of the Abelian Wilson loop can act as separate sources creating the
Coulombic and the solenoidal electric field inside a flux tube. The conjecture
is confirmed by a lattice simulation which shows that the AP flux tube is
composed of these two contributions.
