This book, dedicated to Antonio Aurilia, provides an overview of one of the most enigmatic fields in theoretical physics: the fundamental interactions at energies ranging from the electroweak scale to the Planck scale. This includes physics beyond the standard model, string theory, p-branes, quantum gravity, quantum black holes, and early universe cosmology. Another goal of this work is to present the physical conditions under which evidence of new physics at extreme energies might be uncovered at current (or near-future) experimental facilities.

The book is organized into three parts. The first part introduces fundamental interaction problems and summarizes Prof. Aurilia's life and work, including some unpublished material. The second part forms the book's core, featuring contributions from internationally recognized specialists who collaborated with Prof. Aurilia. The third part summarizes the findings and concludes, with a particular focus on future developments.