Viable intermediate inflation in the mimetic DBI model

Abstract We study the intermediate inflation in mimetic Dirac–Born–Infeld model. By considering scale factor as $$a=a_{0}\exp (bt^{\beta })$$ a = 0 exp ( b t β ) , we show that some ranges of parameters b and $$\beta $$ model is free ghost gradient instabilities. scalar spectral index, tensor tensor-to-scalar ratio this compare results with Planck2018 TT, TE, EE + lowE lensing BAO BK14 data at 68% 95% CL. In regard, find constraints on lead to observationally viable values perturbation parameters. also seek non-Gaussian features primordial perturbations equilateral configuration. performing numerical analysis nonlinearity parameter configuration, amplitude non-Gaussianity DBI predicted be range $$-16.7<f^{equil}<-12.5$$ - 16.7 < f equil 12.5 . that, $$0<b\le 10$$ ≤ 10 $$0.345<\beta <0.387$$ 0.345 0.387 have an instabilities-free gives