Few body bound states in a lattice

The addition of a lattice greatly modifies the properties of few-body bound states in free space. The presence of a lattice does, in general, introduce a dependence of the bound state energy on the total lattice- or quasi-momentum. Interestingly, two particles may form a bound state in the lattice even if the interaction between the particles is repulsive. This contribution reports on our theoretical progress on characterizing two- and three-body bound states in a lattice.