CLASSICAL DOUBLE COPY, THE: New Connections in Gauge Theory and Gravity

Our current understanding of nature is in terms of matter that is acted on by forces. There are four fundamental forces, of which three are described by so-called gauge theories, a type of quantum field theory. The fourth force, gravity, is best described by general relativity, and our traditional ways of thinking about gauge theories and gravity look completely different from each other.

In recent years, an exciting new correspondence called the 'double copy' has emerged, which suggests tha...