Modelling the X-ray fractional root-mean-squared (FRMS) variability spectra of Active Galactic Nuclei

Active Galactic Nuclei (AGN) have been of great interest because of their complex broadband electromagnetic spectra and extreme variability ranging from radio to gamma-rays at the time-scales from a few minutes to years depending upon the physical processes they are governed by. In order to understand the complex nature of AGN X-ray variability, I devised a method to model the fractional root-mean-squared (FRMS) variability spectra and measured the variability power in different spectral components. We applied this method to investigate the nature and origin of energy-dependent variability of various Type 1 AGN. In this talk, I will present several studies with the aim of better understanding the variability mechanism and hence the accretion processes onto the supermassive black holes.