Dualities of the entropy bound
  I study the hypothetical thermodynamic system which saturates the so-called Hubble entropy bound and show that it is invariant under the S- and T-dualities of string theory as well as the interchanges of the eleventh dimension of M-theory. I also discuss how unique the entropy bound is under the dualities and some related issues. 
Naoki Sasakura (YITP, Kyoto Univ.)