Many extensions of the Standard Model of elementary particles – including string theory – predict the existence of fields with TeV-scale mass and extremely weak couplings. Examples of such fields are the gravitino and scalar fields called moduli. These particles can cause several problems to inflationary cosmology. I will first discuss gravitinos, whose abundance is strongly constrained by observations. Such constraints can be violated by gravitinos produced by nonthermal effects after inflation: I will discuss how these effects can be made harmless. I will then describe moduli. Phenomenology requires them to be massive particles. Their potential, however, has only local, shallow minima: how did they get to such minima? I will show that a gas of primordial black holes can entrap the moduli, eventually bringing them to a stable configuration, compatible with observations.

Amherst