Boundedness of Eisenstein integrals on split rank one semisimple symmetric spaces

We characterise the bounded left $K$-invariant normalized Eisenstein integrals on split rank one semisimple symmetric spaces. As a consequence we prove Hausdorff-Young inequality on these spaces. We also prove similar result for $K$-finite Eisenstein integrals on pseudo-Riemannian real hyperbolic spaces.