Scarf for Lifshitz

Polarization of a vacuum as well dispersive and dissipative dielectric media with piece-wise smooth inhomogeneities is studied the goal to clarify question renormalizability diverging electromagnetic stress-energy tensor. First, stress tensor computed Lifshitz approach London forces in non-retarded limit, which after substraction leading free space ultraviolet divergencies still retains associated presence sharp boundaries between inhomogeneities. We call these contributions finite because they become renormalized interface replaced permittivity changing according function spatial coordinates. In addition, such smoothed out exhibits new subleading that appear due its internal structure. To systematically deal polarization inhomogeneous media, Hadamard expansion applied single both unequivocally demonstrate incomplete theory. The above also allows us reveal nature surface tension, proves be purely quantum mechanical. deduced theory tension calculations for real are favorably compared available experimental data. While limit recovers classical boundary conditions electric field uncovers origin apparent local stresses formulation previously pointed literature, problem distinguished type loses information about structure an hence cannot explain tension.