  In this paper we investigate an exact spectrum of quasi normal modes (QNMs)
for perturbations of a scalar field coupled non-minimally with the Einstein
tensor of an uncharged, non-rotating Banados, Teitelboim, and Zanelli (BTZ)
black hole in three-dimensional spacetime. Due to the geometry around the black
hole, the scalar field encounters an effective potential barrier. We study this
potential numerically and derive exact numerical results for the greybody
factors (GFs) and discuss their profiles in terms of the coupling constant and
black hole parameters. We then proceed to derive the Hawking radiation spectrum
for BTZ black hole.
