These are infragravity waves, so called because they are sub-harmonics of the original gravity waves.

这就是亚重力波，之所以这样命名是因为它们是原始重力波的分谐波。

youdao

Sony also announced a number of titles for the system, with Little Deviants, Reality Fighters and Gravity Daze being original games, with franchise titles like Uncharted, Killzone, Wipeout, Resistance, Little Big Planet, Hustle Kings and Hot Shots Golf.

FORBES: Sony Reveals PSP Successor: The NGP