abstract:
I will briefly introduce the main observational characteristics of radio-quiet AGN variability from UV/optical to X-ray, including single-band property and inter-band interrelationship, such as correlation and lag. These variable properties are usually understood within the X-ray reprocessing scenario, however, several challenges against this scenario have been unveiled. Instead, in a series of our works we show that the AGN variability is probably attributed to disk turbulences using a fluctuating accretion disk toy model. Several ongoing projects aiming at better understanding the AGN variability in the time-domain era will be supplemented during the talk.