Description:

Why is the entropy of a black hole proportional to its surface area? One possible answer is holographic --- that microstate threads of information describing the geometry of the black hole cut across the horizon. Maldacena’s famous AdS/CFT correspondence has made concrete this longstanding notion of physical holography. Gravitational evolution in a bulk spacetime can be dual to a boundary description that has no gravity. In the AdS/CFT picture the bulk spacetime evolves gravitationally against an anti-de Sitter space background, and the boundary dual theory is a conformal gauge theory in a spacetime of one dimension less. Recent insights by Ryu and Takayanagi have conjectured that quantum entangled boundary states quantitatively give rise to geometry in the bulk. They do so by explicitly referring to "minimal surfaces" in the bulk, connecting them to the entropy of a related area in the boundary. I will present a conceptually and technically powerful complementary holographic entanglement picture, reformulating Ryu-Takayanagi to no longer refer to minimal surfaces, and suggesting a new way to think about the holographic principle and the connection between spacetime gravitation and information. I will introduce the idea of bit threads, and show how they can be used for fun and profit.

Seminar Speaker: Bogdan Stoica, Harvard University

Keywords: Physics, Astronomy, HEP