Introduction to string theory

Abstract

Emerged in the late 1960s, originally as a proposition for explaining strong interactions, String Theory proved to be a model potentially capable of going far beyond that; changing its scope of description rather consisting of only one of nature's fundamental interactions to all four. In this context, it is now known that the best model for describing electromagnetic, strong nuclear, and weak nuclear interactions is quantum mechanics; while General Relativity Theory fulfills this role for gravity. There are obstacles, however, that prevent both of them from working together harmoniously and consistently. String Theory then presents itself as a candidate for unification by proposing consistent forms of description for the four fundamental interactions; respecting, also, the usual quantum mechanics quantization procedures and the notions of General Relativity spacetime. To do so, it breaks one of the most basic paradigms of physics: its most fundamental object is a one-dimensional entity, as opposed to the basic idea that has long been in physics: of point particles. Thus, String Theory presents itself today as a topic of study of unique importance for physics, being essential for the evolution of our understanding of the most basic functioning of nature. In view of this, the research on which this project is based aims to introduce the student to this field of study, in a solid and formal way, preparing him to continue with further studies in physics during graduate school. Thus, the scope of this work consists in the study of the fundamentals of bosonic strings, culminating in some of its unfolding, such as D-branes, string charges, etc. (AU)