Orbital free entropy, revisited Yoshimichi Ueda Primary 46L54: Secondary 52C1728A7894A17Free probabilityfree entropyfree entropy dimensionmutual informationnon-commutative random variablefree unitary Brownian motion We give another definition of orbital free entropy introduced by Hiai, Miyamoto, and us, which does not need the hyperfiniteness assumption for each given random multi-variable. The present definition is somehow related to one of its several recent approaches due to Biane and Dabrowski, but can be shown to agree with the original definition completely, and is much closer to the original approach. Indiana University Mathematics Journal 2014 text pdf 10.1512/iumj.2014.63.5220 10.1512/iumj.2014.63.5220 en Indiana Univ. Math. J. 63 (2014) 551 - 577 state-of-the-art mathematics http://iumj.org/access/