  We study the temperature dependence of the electrical resistivity of
interacting two-dimensional metallic systems. We perform a numerical simulation
of the nonequilibrium state based on semiclassical Boltzmann transport theory.
Through our simulation, we demonstrate that deviations from the predictions of
standard Fermi-liquid theory can arise due to the special scattering geometry
of umklapp processes, in special cases even in the ultra-low-temperature limit.
Umklapp scattering is required to relax the total momentum of the quasiparticle
distribution function. We investigate the transport properties of a
two-dimensional system of quasiparticles with repulsive on-site interactions
and nonmagnetic impurity scattering on a square lattice with a single-orbital
tight-binding model of the dispersion. We demonstrate that unconventional
scaling properties of the electrical resistivity, which are often interpreted
as indication of a non-Fermi-liquid state, can arise due to special geometric
conditions of the Fermi surface. The appearance of robust deviations from the
predictions of Fermi-liquid theory within our simple model presents a novel
viewpoint in order to interpret unconventional transport properties in
electron-electron scattering dominated metallic systems.
