Some Aspects of the Tachyon Inflation with Superpotential in
  Confrontation with Planck2018 Data
  We study the tachyon inflation in the presence of the superpotential as an
inflationary potential. We study the primordial perturbations and their
non-gaussian feature in the equilateral configuration. We use the Planck2018
TT, TE, EE+lowE+lensing+BK14+BAO joint data at $68\%$ CL and $95\%$ CL, to
perform numerical analysis on the scalar perturbations and seek for the
observational viability of the tachyon inflation with superpotential. We also
check the observational viability of the model by studying the tensor part of
the perturbations and comparing the results with Planck2018 TT, TE,
EE+lowE+lensing+BK14+BAO+ LIGO$\&$Virgo2016 joint data at $68\%$ CL and $95\%$
CL. By studying the phase space of the model's parameters, we predict the
amplitude of the equilateral non-gaussianity in this model. The reheating phase
after inflation is another issue that is explored in this paper. We show that,
in some ranges of the model's parameters, it is possible to have an
observationally viable tachyon model with superpotential.
