  A Hubbard-Luttinger model is developed for qualitative description of
one-dimensional motion of interacting Pi-conductivity-electrons in carbon
single-wall nanotubes at low temperatures. The low-lying excitations in
one-dimensional electron gas are described in terms of interacting bosons. The
Bogolyubov transformation allows one to describe the system as an ensemble of
non-interacting quasi-bosons. Operators of Fermi-excitations and Green
functions of fermions are introduced. The electric current is derived as a
function of potential difference on the contact between a nanotube and a normal
metal. Deviations from Ohm law produced by electron-electron short-range
repulsion as well as by the transverse quantization in single-wall nanotubes
are discussed. The results are compared with experimental data.
