  Metals approaching the Mott insulator generate a new hierarchy in the
electronic structure accompanied by a momentum dependent electron
differentiation, beyond the Mott-Hubbard, Brinkman-Rice and Slater pictures of
the Mott transition. To consider such nonlinear phenomenon, we develop an
analytic nonperturbative theory based on operator projections combined with a
self-consistent treatment of the low-energy excitations. This reproduces the
formation of the Hubbard bands, Mott gap, spin fluctuations, mass divergence,
diverging charge compressibility, and strongly renormalized flat and damped
dispersion similar to angle-resolved photoemission data in high-T_c cuprates.
Main structures in electronic spectra show a remarkable similarity to numerical
results.
