The development of unified theory
Unifying all natural interactions is an ultimate object of physics. To realize that, physicist used plenty of mathematical tools like group theory and differential geometry, and combined them with physical theory.
Nowadays, QFT is a framework of unified theory, and the corresponding mathematical theory is gauge theory. In these theories QED and QCD are the representative theory of interactions, and electroweak theory is also regarded as the unified theory of electromagnetic and weak interaction.
Nowadays, QFT is a framework of unified theory, and the corresponding mathematical theory is gauge theory. In these theories QED and QCD are the representative theory of interactions, and electroweak theory is also regarded as the unified theory of electromagnetic and weak interaction.