In the modern version of 5-D general relativity where the fifth dimens
ion induces matter in 4-D space-time, a choice of coordinates and its
restrictions on the geometry (a gauge) dictates the physics of die gra
vitational, electromagnetic, and scalar fields (spin 2, 1, 0). We exte
nd previous work by concentrating on two related problems. First, we u
se the lapse and shift formalism to carry out a (4 + 1) split of Kaluz
a-Klein theory valid in any gauge. Second, we use a conformal gauge to
simplify the 5-D field equations, find a plane-wave solution, and ide
ntify the energy and momentum of the particle associated with it. (C)
1998 American Institute of Physics. [S0022-2488(98)01504-7].