Revisiting CMB constraints on Warm Inflation
  We revisit the constraints that Planck 2015 temperature, polarization and
lensing data impose on the parameters of warm inflation. To this end, we study
warm inflation driven by a single scalar field with a quartic self interaction
potential in the weak dissipative regime. We analyse the effect of the
parameters of warm inflation, namely, the inflaton self coupling $\lambda$ and
the inflaton dissipation parameter $Q_P$ on the CMB angular power spectrum. We
constrain $\lambda$ and $Q_P$ for 50 and 60 number of e-foldings with the full
Planck 2015 data (TT, TE, EE + lowP and lensing) by performing a Markov-Chain
Monte Carlo analysis using the publicly available code {\tt CosmoMC} and obtain
the joint as well as marginalized distributions of those parameters. We present
our results in the form of mean and 68 \% confidence limits on the parameters
and also highlight the degeneracy between $\lambda$ and $Q_P$ in our analysis.
From this analysis we show how warm inflation parameters can be well
constrained using the Planck 2015 data.
