Abstract

High energy theoretical physics is in the midst of a paradigm shift: holography. Holography states that any theory without gravity should have an alternative description as a theory with no gravity in one less dimension. On the one hand holography implies that the three spatial dimensions of our Universe should be described in terms of a flatland theory in which there is no gravity, but on the other hand we can also use holography to describe many novel strongly interacting systems via gravitational phenomena such as black holes in a higher dimensional world. After introducing and explaining these ideas, I will discuss the current state of the art: what do know about the flatland theory describing our Universe? how far can we go in modeling systems such as superconductors by gravity in higher dimensions?