DEPARTMENT COLLOQUIUM | Four Impressions from the Gauge/String Duality

String theory naturally came about as an attempt to describe strong hadronic interactions. It was soon rightfully dethroned by Quantum Chromodynamics - the theory of strong interactions. In the early 80's string theory reemerged as a consistent theory of quantum gravity and became the leading candidate for a theory of everything. More recently, however, string theory has played a crucial role as a dual description of gauge theories, that is a description of gauge theories in terms of gravity fields. This development completes a full circle back to its origins. The Gauge/String duality applies to many interesting systems and is particularly powerful for strongly coupled field theories. Using examples of my own research, I will impressionistically describe four areas where ideas from this duality have proven fruitful.