W.G. Unruh, Professor

B.Sc., Manitoba (67)
M.A., Ph.D., Princeton (69, 71)
NRC Postdoct., Birbeck Coll., London (71--72)
A.P. Sloan Fell., (76--82)
UBC Killam Sr. Fell. & Visit. Sci., Chicago, Cambridge & Santa Barbara (83--84)
Rutherford Medal, Royal Society of Canada
CAP Herzberg Medal (83)
Steacie Fellow (84--86); Steacie Prize (84)
FRSC (83) 
Rutherford Lect., RSC (85)
JSPS Sr. Fell., Japan (86)
Fell. & Director, Cosmology Programme, CIAR (86--)
J. Bieley Award UBC (89)
Killam Sr. Research Prize UBC (90)
CAP Medal of Achievement (95)
Killam Prize in Natural Sciences --Canada Council (96)
CAP/CRM Medal in Theoretical and Mathematical Physics (96)

Research Interests

• applying quantum mechanics to gravity and the role of time in such a theory. Due to coordinate invariance, the theory is usually formulated with no explicit time, but must be interpreted with time defined (rather than measured) by clock readings. This leads to peculiar difficulties, suggesting that one reformulate the theory with explicit (but unmeasureable) time.

• quantum processes in the early universe, including the onset of inflation, quantum generation of density fluctuations, and formation of cosmic strings

• The process of black hole evaporation, discovered by Hawking, and still a mystery in its physical origin. A fluid analog of the process may help to unravel this mystery.

• Concern about the measurement process in quantum field theory has led me, for example, to the realisation that particles are really defined by "particle detectors"; an accelerated particle detector in the vacuum would detect particles.

• fundamental quantum limits on the measurement process of detectors and amplifiers, especially as applied to gravity wave detectors. Here I have examined the effects of a quantum system coupling to its environment, and the decoherence and measurement induced by such a coupling.

• Finally, my students and I have investigated various techniques for solving General Relativity equations numerically --- eg., multigrid, and other selective mesh refinements, numerical coordinate patches, and horizontal boundary conditions rather than stopping evolution in regions where singularities may form. In general, my philosophy is to study techniques rather than to find solutions with (possibly) unreliable, crude techniques.

Selected Publications

"Notes on Black Hole Evaporation", Phys. Rev. D14, 870 (1976), W.G. Unruh.

"Quantum Decoherence and Brownian Motion of a Harmonic Oscillator", Phys. Rev. D ???, W.G. Unruh and W.H. Zurek.

"An introduction to the Multi-Grid Method for Numerical Relativists", General Rel. & Grav. 18, 813 (1985), M. Choptuik and W.G. Unruh.