  We revisit the holographic calculation of the decay modes of the BTZ
blackhole perturbed by a scalar probe. We carry out a finite temperature
expansion of the torus two point function of large central charge $(c)$ CFTs in
order to obtain the corrections to blackhole quasinormal modes. We take the
contribution of the lightest primary above the vacuum, with dimension
$\Delta_{\chi}$ and upper bound of $c/6$, in the torus two point function. We
exploit the modular properties of 2D CFT on the torus to connect the expression
of thermal two point function at high temperature with the same at low
temperature. The correction term can be expressed as a four point function on
the Riemann sphere. In the dual bulk theory the corrections are expected to
arise due to the presence of a light matter field in the spacetime along with
gravity. In the holographic limit the effects of this correction term is
encoded in the change in blackhole temperature. This leads to new quasinormal
modes and modification of thermalization time scale.
