Professor Mann works on gravitation, quantum physics, and the overlap between these two subjects. He is interested in questions that provide us with information about the foundations of physics, particularly those that could be tested by experiment.

Professor Mann has a lively and energetic research group of about 10 graduate and undergraduate students, where we address a number of interesting questions in physics, such as

- How would relativity influence how a quantum computer worked?
- Could we use a quantum probe to peek inside a black hole?
- Is it possible that the Big Bang could be replaced with a black hole at the beginning of time?

## Research interests

- Gravitation and particle physics
- Tests of gravitational theory
- Black holes
- Quantum gravity and string theory

## Research activities

Research is presently directed in three areas:

- New tests of the equivalence principle are being designed and investigated. Such tests provide us with important information about the gravitational force, and may give some clues as to the structure of quantum gravity. Specific examples include gravitational redshifts of quantum vacuum energies, non-metric effects on anomalous magnetic moments, gravitational depolarizatinon of polarized light and neutrino flavour mixing due to gravitational effects.
- Physical properties of black holes are being studied as a means of gaining insight into quantum gravity. The formulation of the thermodynamics of gravitating systems of finite size (such as a black hole in a box) is being carried out to this end. Pair production of black holes and quantum corrections to the laws of thermodynamics are being investigated as a means of gaining a fundamental understanding of the origin of black hole entropy.
- Theories of lower dimensional gravity are being investigated. Such theories model many important conceptual elements of classical and quantum gravity in a context that is mathematically simple and elegant. Specific projects include a study of the N-body problem, gravitational collapse, dilatonic black holes, and interior structure of black holes. Lower-dimensional black holes.

## Selected publications

- T. Hambye, R.B. Mann and U. Sarkar.
*Test of Special Relativity from K Physics.* Phys. Lett. B. (accepted January 8, 1998).
- R.B. Mann and S.N. Solodukhin.
*Universality of Quantum Entropy for Extreme Black Holes.* Nucl. Phys. B (accepted January 6, 1998).
- R.B. Mann.
*Charged Topological Black Hole Pair Creation.* Nucl. Phys. B (accepted December 24, 1997).
- M.E. Knutt-Wehlau and R.B. Mann.
*Supergravity from a Massive Superparticle and the Simplest Super Black Hole.* Nucl. Phys. B (accepted October 23, 1997).
- W.L. Smith and R.B. Mann.
*Formation of Topological Black Holes from Gravitational Collapse.* Phys. Rev. D **56**, 4942-4947. (1997)
- C. Alvarez and R.B. Mann.
*The Equivalence Principle and Experiments.* Phys. Lett. B **420**, 83-87. (1997)
- P.T. Landsberg and R.B. Mann.
*Thermodynamic Classifications and Dilatonic Black Holes.* Gen. Rel. Grav. **29**, 1269-1281. (1997)
- R.B. Mann.
*Black Holes of Negative Mass.* Class. Quant. Grav. **14**, 2927-2930. (1997)
- J.S.F. Chan and R.B. Mann.
*Scalar Wave Falloff in Asymptotically Anti-De Sitter Backgrounds.* Physical Review D **55**, 7546-7566. (1997)
- R.B. Mann.
*Testing the Equivalence Principle Using (g-2) Experiments.* Modern Physics Letters A **12**, 1209- 1224. (Invited review). (1997)
- R.B. Mann.
*Pair Production of Topological Black Holes.* Classical and Quantum Gravity Letters **14**, L109- L114. (1997)
- R.B. Mann and T. Ohta.
*Exact Solution of Relativistic Two Body Motion in Dilaton Gravity.* Classical and Quantum Gravity**14**, 1529-1266. (1997)
- R.B Mann and S.N. Solodukhin.
*Quantum Scalar Field on a Three-Dimensional BTZ Black Hole Instanton: Heat Kernel, Effective Action, and Thermodynamics.* Physical Review D **55**, 3622-3632. (1997)
- R.B. Mann and G. Papadopolous.
*Killing Spinors, the AdS Black Hole and I(ISO(2,1) Gravity.* Physical Review D **55**, 2119-2123. (1997)
- C. Alvarez and R.B. Mann.
*The Equivalence Principle in the Non-Baryonic Regime.* Physical Review D **55**, 1732-1739. (1996)
- J. Creighton and R.B. Mann.
*Quasilocal Thermodynamics of Two-dimensional Black Holes.* Physical Review D **54**, 7476-7482. (1996)