Baxter Q-operators in Ruijsenaars-Sutherland hyperbolic systems: one- and two-particle cases

In these notes we review the technique of Baxter Q-operators in the Ruijsenaars-Sutherland hyperbolic systems in the cases of one and two particles. Using these operators we show in particular that eigenfunctions of these systems admit two dual integral representations and prove their orthogonality and completeness.