Superstring Phenomenology: An Overview

TL;DR

This paper surveys string phenomenology, contrasting the pre-1995 perturbative picture with the post-1995 nonperturbative insights. It details model-building approaches (Calabi–Yau compactifications, orbifolds, and Gepner models) and the structure of the 4D effective action determined by K, W, and f, highlighting non-renormalization theorems and the role of the dilaton S. It also outlines core model-independent predictions and persistent challenges, such as moduli stabilization, unification, and SUSY breaking, and it tracks the shift toward a nonperturbative framework via dualities and M-theory. Overall, the work emphasizes how nonperturbative effects and higher-dimensional perspectives reshape the landscape of viable string vacua and their phenomenological implications, while acknowledging unresolved issues like the cosmological moduli problem and the string unification discrepancy.

Abstract

The different aspects of superstring phenomenology before and after 1995 are briefly reviewed. (Contribution to the conference SUSY97)