Strings and Branes : New Paradigm of Theoretical Physics

String Theory is expected to provide the framework combining the principles of relativity and quantum. Through the revolutionary developments in the string theory triggered by the discovery of the branes in 1994, many deep and new properties of the theory have been discovered. The branes can provide the new paradigm for understanding many nonperturbative field theory properties. Low energy brane dynamics are described by the field theoy and can be used to understand many nonperturbative field theory properties. The most important newly discovered property may be the so-called AdS-CFT correspondence or the holography principle, which relates the strongly interacting field theory with the corresponding effective gravity theory in one dimension higher spacetime. Some examples that have been studied include the heavy ion physics and the various strongly correlated phenomena in condensed matter physics.