  The low frequency quasi periodic oscillations (QPOs) are commonly observed
during hard states of black hole binaries. Several studies have established
various observational/empirical correlations between spectral parameters and
QPO properties, indicating a close link between the two. However, the exact
mechanism of generation of QPO is not yet well understood. In this paper, we
present our attempts to comprehend the connection between the spectral
components and the low frequency QPO observed in GRS 1915+105 using the data
from NuSTAR. Detailed spectral modeling as well as the presence of the low
frequency QPO and its energy dependence during this observation have been
reported by Miller et al. (2013) and Zhang et al. (2015) respectively. We
investigate the compatibility of the spectral model and energy dependence of
the QPO by simulating light curves in various energy bands for small variation
of the spectral parameters. The basic concept here is to establish connection,
if any, between the QPO and the variation of either a spectral component or a
specific parameter, which in turn can shed some light on the origin of the QPO.
We begin with the best fit spectral model of Miller et al. (2013) and simulate
the light curve by varying the spectral parameter at frequencies close to the
observed QPO frequency in order to generate the simulated QPO. Further we
simulate similar light curves in various energy bands in order to reproduce the
observed energy dependence of RMS amplitude of the QPO. We find that the
observed trend of increasing RMS amplitude with energy can be reproduced
qualitatively if the spectral index is assumed to be varying with the phases of
the QPO. Variation of any other spectral parameter does not reproduce the
observed energy dependence.
