The recent developments in observational cosmology have caused a burst in our understanding of the early universe. Likewise, a significant effort has been devoted to deepen our theoretical description of the inflationary dynamics itself. In this talk I will discuss a number of field theory methods which make our theoretical understanding of the early universe microphysics a match to the present era of precision cosmology. First, I will introduce the dynamical renormalization group technique as a means to evolve cosmological perturbations during inflation. Second, I will discuss how this method can allow the halo bias to be a discriminant between single and multiple field inflation. Finally, I will suggest a consistency test between observables based on a bottom-up approach to inflation which might enable us to rule out single-field models against data.