  In this paper, we examine the effect of introducing a conical disclination on
the thermal and optical properties of a two dimensional GaAs quantum dot in the
presence of a uniform and constant magnetic field. In particular, our model
consists of a single-electron subject to a confining Gaussian potential with a
spin-orbit interaction in the Rashba approach. We compute the specific heat and
the magnetic susceptibility from the exact solution of the Schr\"odinger
equation via the canonical partition function, and it is shown that the peak
structure of the Schottky anomaly is linearly displaced as a function of the
topological defect. We found that such defect and the Rashba coupling modify
the values of the temperature and magnetic field in which the system behaves as
a paramagnetic material. Remarkably, the introduction of a conical disclination
in the quantum dot relaxes the selection rules for the electronic transitions
when an external electromagnetic field is applied. This creates a new set of
allowed transitions causing the emergence of semi-suppressed resonances in the
absorption coefficient as well as in the refractive index changes which are
blue-shifted with respect to the regular transitions for a quantum dot without
the defect.
