Leonard Parker


Leonard Emanuel Parker (born Leonard Pearlman; in 1938) is a distinguished professor emeritus of physics and a former director of the Center for Gravitation and Cosmology at the University of Wisconsin–Milwaukee. During the late 1960s, Parker established a new area of physics—quantum field theory in curved spacetime. Specifically, by applying the technique of Bogoliubov transformations to quantum field theory with a changing gravitational field, he discovered the physical mechanism now known as cosmological particle production. His breakthrough discovery has a surprising consequence: the expansion of the universe can create particles out of the vacuum.[1] His work inspired research by hundreds of physicists and has been cited in more than 2,000 research papers; it was credited in the memoirs of Soviet physicist Andrei Sakharov and helped Stephen Hawking discover the creation of particles by black holes.[citation needed]

Leonard E. Parker
Born1938 (age 85–86)
New York City, US
Alma materHarvard University
Known forQuantum field theory in curved spacetime
Scientific career
FieldsQuantum physics
InstitutionsUniversity of Wisconsin–Milwaukee
Doctoral advisorSidney Coleman
Doctoral studentsLaura Mersini-Houghton
Prakash Panangaden

Along with David Toms of Newcastle University, Parker co-wrote a latest addition to graduate-level textbooks on quantum field theory in curved spacetime, entitled Quantum Field Theory in Curved Spacetime: Quantized Fields and Gravity (Cambridge University Press, 2009, ISBN 978-0-521-87787-9).

He received his PhD from Harvard University in 1967. His advisor was Sidney Coleman.

Awards and honors



  1. ^ Parker, Leonard; Navarro-Salas, Jose (2017). "Fifty years of cosmological particle creation". arXiv:1702.07132 [physics.hist-ph].
  • Parker's faculty page at University of Wisconsin–Milwaukee
  • The Center for Gravitation and Cosmology
  • Milwaukee Journal Sentinel article about Leonard Parker