Multifractality Signatures in Quasars Time Series. I. 3C 273
  The presence of multifractality in a time series shows different correlations
for different time scales as well as intermittent behaviour that cannot be
captured by a single scaling exponent. The identification of a multifractal
nature allows for a characterization of the dynamics and of the intermittency
of the fluctuations in non-linear and complex systems. In this study, we search
for a possible multifractal structure (multifractality signature) of the flux
variability in the quasar 3C 273 time series for all electromagnetic wavebands
at different observation points, and the origins for the observed
multifractality. This study is intended to highlight how the scaling behaves
across the different bands of the selected candidate which can be used as an
additional new technique to group quasars based on the fractal signature
observed in their time series and determine whether quasars are non-linear
physical systems or not. The Multifractal Detrended Moving Average algorithm
(MFDMA) has been used to study the scaling in non-linear, complex and dynamic
systems. To achieve this goal, we applied the backward ({\theta} = 0) MFDMA
method for one-dimensional signals. We observe weak multifractal (close to
monofractal) behaviour in some of the time series of our candidate except in
the mm, UV and X-ray bands. The non-linear temporal correlation is the main
source of the observed multifractality in the time series whereas the heaviness
of the distribution contributes less.
