Gravitation and black holes
Georgi Dvali wins ERC Advanced Grant
LMU theoretical physicist Professor Georgi Dvali and Professor Cesar Gomez (Institute of Theoretical Physics, Madrid) have been awarded one of the coveted Advanced Investigator Grants by the European Research Council (ERC), which is worth about 1.2 million euros. ERC Advanced Grants are bestowed on European researchers whose track record identifies as leaders in their respective fields, to enable them to undertake ground-breaking, high-risk projects.
Georgi Dvali is a world-renowned expert in the field of Theoretical Physics, whose interests include the structure of space-time and the nature of gravitation. In his ERC-funded project in collaboration with Cesar Gomez, he will investigate two fundamental issues in the area of gravitation. The first concerns the behavior of the gravitational force on ultrashort scales, where the energies of the particles that mediate the force are extremely high. The second relates to the quantum physical description of massive black holes.
Dvali and Gomez will employ a novel approach which they believe provides a way of combining the two problems – which at first sight appear to be quite distinct – within a common framework. So far, it has been generally assumed that the quantum theory is relevant only at the microscopic scale of elementary particles, whereas the behavior of macroscopic objects, such as people, planets, galaxies or black holes, is subject to the laws of classical physics, including the General Theory of Relativity, which describes gravity as the fundamental force that shapes the Universe.
The approach adopted by Dvali and Gomez dispenses with this stereotypic dichotomy. The two researchers postulate that – irrespective of their size – black holes must be viewed as quantum objects, and therefore cannot be adequately described by the tenets of classical physics. They regard black holes as so-called Bose-Einstein condensates, as systems that consist of indistinguishable particles called gravitons – the hypothetical massless particles thought to carry the gravitational force. A Bose-Einstein condensate behaves as a single quantum object, because essentially all its constituent particles are in the same quantum state – close to a quantum critical point, the transition point between two quantum phases. This in turn implies that the macroscopic black hole system should be extremely sensitive to random fluctuations in its total energy – so-called quantum fluctuations – a property which cannot be accounted for in terms of the classical laws of physics.
“When analyzed using the laws of classical physics, black holes display some mysterious, indeed paradoxical, properties. Our theory could provide a key to a better understanding of their nature,” Dvali says. “We are convinced that, if one looks at the physics of black holes from the standpoint of quantum field theory, one can explain all of the apparent mysteries and paradoxes associated with these objects – and answer fundamental questions in physics and cosmology.”
Dvali was born in Tiflis in Georgia, where he attended university and obtained his doctorate. After spells at the International Center for Theoretical Physics in Trieste, at CERN in Geneva and at the University of Pisa, he joined the faculty of New York University in 1998 and has held a named Silver Professor Chair there since 2006. Dvali is a recipient of the New York City Mayor's Award for Excellence in Science and Technology. In 2008, Dvali was awarded an Alexander von Humboldt Professorship and was appointed to the Chair of Theoretical Particle Physics at LMU’s Arnold Sommerfeld Center for Theoretical Physics. Dvali is also a Director of the Max Planck Institute for Physics. göd