Dynamics of circumstellar disks in Be-star binaries

In isolated Be stars, the circumstellar disk is affected by the interactions with the central star via the radiation, the wind, 
and the mass injection into the disk. These interactions, together with the viscous interaction inside the disk, determine the 
disk structure and its evolution. In Be stars in binaries, the presence of the companion adds significant complications to the 
dynamics of the circumstellar disk. For instance, the tidal torque by the companion truncates the circumstellar disk in 
systems with low to moderate orbital eccentricity. The tidal torque can also give rise to the disk warping and/or precession. If 
the companion is a pulsar with a pulsar wind, the circumstellar disk can become a site where the high energy emission arise. 
In this review talk, I will discuss the dynamical behavior of the Be circumstellar disk caused by various interactions 
characteristic to binary systems.