%0 Journal Article %T Properties of universal bosonic tetramers %A A. Deltuva %J Physics %D 2012 %I arXiv %R 10.1007/s00601-012-0313-6 %X The system of four identical bosons is studied using momentum-space equations for the four-particle transition operators. Positions, widths and existence limits of universal unstable tetramers are determined with high accuracy. Their effect on the atom-trimer and dimer-dimer scattering observables is discussed. We show that a universal shallow tetramer intersects the atom-trimer threshold twice leading to resonant effects in ultracold atom-trimer collisions. %U http://arxiv.org/abs/1202.0167v1