Special Unipotent Representations with Half Integral Infinitesimal Characters

For any special nilpotent orbit, let $\frac{1}{2}h^{\vee}$ be one half of the semisimple element of a Jacobson-Morozov triple associated to the orbit. In 1985, Barbasch and Vogan defined the notion of special unipotent representations with infinitesimal character $(\frac{1}{2}h^{\vee},\frac{1}{2}h^{\vee})$. Some properties of such representations were discovered when $\frac{1}{2}h^{\vee}$ is integral. In this manuscript, we give a complete proof of these properties when $\frac{1}{2}h^{\vee}$ is not integral.