Warm DBI inflation with constant sound speed

We study warm inflationary scenario driven by the Dirac-Born-Infeld (DBI) noncanonical scalar field. We consider the Anti-de Sitter (AdS) warp factor f(ϕ) = f0/ϕ4 and check the viability of the quartic potential V (ϕ) = λϕ4/4 with constant sound speed cs in light of the Planck 2015 data. Prediction of this potential in the cold DBI setting, like the standard canonical scenario, is in conflict with the Planck data in the r−ns plane. But we show that in the setup of warm DBI inflation, the result of model can be compatible with the 68% CL constraints of Planck 2015 TT,TE,EE+lowP data in the intermediate and high dissipation regimes. We also conclude that our model is compatible with the observations without disturbing the essential condition T H of warm inflation. Finally, we specify the parameter spaces of ( ) and λ−cs and find that our model is in consistency with the Planck 2015 results provided that f0 ≳ 1015 and λ≲ 10−13.