Prof. Ramy Brustein (Ben-Gurion)

Date: Mar. 29, 2009

Title: Quantum Black Holes challenge basic principles of Quantum Mechanics

Abstract: 

Bekenstein discovered that Black Holes have entropy proportional to
the area of their horizon and Hawking discovered that Quantum Black
Holes radiate. Ever since, the ongoing quest for understanding the
fundamental laws that govern the physics of Black Holes has attracted
and puzzled many researchers. The main motivation for this undying
theoretical interest are the hints that black holes provide the need
for fundamental changes in the laws of quantum mechanics.

I will first review and explain some basic facts about the
thermodynamics of quantum black holes and the puzzles and paradoxes
that their existence apparently implies. I will discuss some of the
proposed resolutions and some of the lessons that string theory and
the gauge-gravity correspondence have taught us.

Then I will present my (still controversial) approach to understanding
Quantum Black Holes: the entanglement approach. This approach
considers the fundamental physical objects to be the global quantum
state of the black hole and the unitary quantum evolution
operator. This approach has several obvious advantages: it relies on
the standard rules of quantum mechanics, it leads naturally to
area-law entropy and it can incorporate the observer dependence of
black hole thermodynamics. I will also describe the unresolved issues
and open problems in the entanglement approach.