Further phenomenological properties. Strings and cosmology
In previous chapters we have considered the main properties of the 4d effective action of string compactifications, regarding low-energy particle spectra, anomaly cancellation, Yukawa couplings, supersymmetry breaking soft terms, and moduli fixing. In this chapter we discuss in more detail several other general phenomenological features of string theory models of particle physics. These include the possible range of the string scale, gauge coupling unification, axions, baryon and lepton number violation, Z′-bosons, and possible signatures of low-scale string models. We also introduce some aspects of string cosmology and inflation.
16.1 Scales and unification in string theory
In string ...