Research Line: Field Theories and Gauge Theories
Lead Researcher(s): Cássius Anderson Miquele de Melo, Rodrigo Rocha Cuzinatto
Description:

Field theory is a fundamental concept in physics that provides a framework for understanding the behavior of physical fields, which are present throughout the universe. At its core, field theory describes how these fields interact with matter and with each other, governing fundamental forces and phenomena in nature.

Field theory plays a central role in formulating the standard model of particle physics. According to quantum field theory (QFT), particles are excitations of underlying fields that fill space. QFT treats particles and fields on equal footing, with interactions between particles described by the exchange of virtual particles mediated by their associated fields.

Beyond the standard model, theoretical physicists are exploring more comprehensive field theories that could unify all fundamental forces, including gravity, in a single theoretical framework. Examples of these extended models include theories with higher-order derivatives and new fields representing possible variations in fundamental constants.

On the other hand, gauge theory is a fundamental area of physics that underpins our understanding of the fundamental forces and particles of the universe. It is a mathematical structure used to describe how fields interact with matter and how these interactions are governed by certain symmetries, called gauge symmetries.

At its core, gauge theory is a branch of field theory where the focus is on understanding fundamental forces and their carrier particles, known as gauge bosons.

The term “gauge” refers to a certain type of symmetry principle inherent in the mathematical description of fields. Symmetry plays a crucial role in physics, often serving as a guide to understanding the underlying laws of nature. In gauge theory, these symmetries are associated with field transformations that leave physics unchanged.

One of the most familiar examples of gauge theory is quantum electrodynamics (QED), which describes the interaction between charged particles and the electromagnetic field. In QED, the symmetry principle arises from the requirement that the laws of physics remain invariant under certain transformations of the electromagnetic potential. This symmetry leads to the concept of gauge invariance, where different choices of electromagnetic potential describe the same physical situation. Currently, theoretical physicists continue to explore more comprehensive gauge theories that could unify all fundamental forces in a single theoretical framework. Gauge theories with higher-order derivatives or exploring new types of mathematical symmetries are examples of recent research topics.

In this research line, we contribute to the study of field interactions with matter and their phenomenological consequences in various aspects. Examples include:

  1. The description of gravitation as a first and second-order gauge theory for Lorentz and Poincaré symmetry groups (this subject is a connection point with the “Gravitation and Cosmology” research line);
  2. Application of Podolsky’s Generalized Electrodynamics to different classical and quantum contexts, aiming at constraining Podolsky’s mass;
  3. Exploring how new symmetries can be used to describe dark matter models and predict their forms of interaction;
  4. Studying theoretical and formal aspects, such as the equivalence between different geometric models and scalar-multitensorial models;
  5. Investigating modified electrodynamics (non-linear and higher-order) as a way to describe high-energy phenomena.