  This tutorial is a theoretical work, in which we study the physics of
ultra-cold dipolar bosonic gases in optical lattices. Such gases consist of
bosonic atoms or molecules that interact via dipolar forces, and that are
cooled below the quantum degeneracy temperature, typically in the nK range.
When such a degenerate quantum gas is loaded into an optical lattice produced
by standing waves of laser light, new kinds of physical phenomena occur. These
systems realize then extended Hubbard-type models, and can be brought to a
strongly correlated regime. The physical properties of such gases, dominated by
the long-range, anisotropic dipole-dipole interactions, are discussed using the
mean-field approximations, and exact Quantum Monte Carlo techniques (the Worm
algorithm).
