Lee-Wick radiation induced bouncing universe models
  The present article discusses about the effect of a Lee-Wick partner infested
radiation phase of the early universe. As Lee-Wick partners can contribute
negative energy density so it is always possible that at some early phase of
the universe when the Lee-Wick partners were thermalized the total energy
density of the universe became very small making the effective Hubble radius
very big. This possibility gives rise to the probability of a bouncing
universe. As will be shown in the article that a simple Lee-Wick radiation is
not enough to produce a bounce. There can be two possibilities which can
produce a bounce in the Lee-Wick radiation phase. One requires a cold dark
matter candidate to trigger the bounce and the other possibility requires the
bouncing temperature to be fine tuned such as all the Lee-Wick partners of the
standard fields are not thermalized at the bounce temperature. Both the
possibilities give rise to blue-tilted power spectrum of metric perturbations.
Moreover the bouncing universe model can predict the lower limit of the masses
of the Lee-Wick partners of chiral fermions and massless gauge bosons. The mass
limit intrinsically depends upon the bounce temperature.
