Abstract: The next few years will bring a wealth of new information about the primordial cosmological fluctuations. In this talk, I will discuss how observable non-Gaussianities and gravitational wave signals encode the physics of the early universe. First I will discuss signatures of global symmetries in the early universe, arguing that even the simplest slow roll inflation models can lead to observable non-Gaussianity and primordial gravity waves. Next, I will consider more generally the possibility to probe how the inflaton couples to radiation.