Implementation of two-field inflation for cosmic linear anisotropy
  solving system
  We outline the modifications in the numerical Boltzmann code Cosmic Linear
Anisotropy Solving System (CLASS) in order to include extra inflationary
fields. The functioning of the code is first described, how and where
modifications are meant to be done are later explained. In the present study,
we focus on the modifications needed for the implementation of a two-field
inflationary model, with canonical kinetic terms and a polynomial potential
with no cross terms, presenting preliminary results for the effect of the
second field on the spectra. The adaptability of the code is exploited, making
use of the classes and structures of C and the generic Runge-Kutta integration
tool provided by the program.
