Jan Ambjørn
Encyclopedia
Jan Ambjørn is a Danish
physicist
regarded as the primary founder of Causal Dynamical Triangulation Theory (CDT).
Ambjørn began in the early 1990s searching for a physics model that bonded quantum mechanics
and relativistic gravity
in a way that didn't require supersymmetry
. By 1994, he argued a simpler way to represent quantum gravity
was to use Lorentzian
space-time geometry as a framework. His first major publication on the lattice model
that would become CDT theory was released in 1998. It was then that he and Renate Loll
made triangulation and the causal approach the cornerstones to the lattice gauge theory
.
The theory of Causal Dynamical Triangulations faced harsh scrutiny for some years because most physicists preferred models that required more dimensions
and a fixed background.
By 2004, Ambjørn's assertion of the benefits to a non-perturbative quantum gravity
model regained attention.
As of 2007, Ambjørn continues to research lattice gauge, string, and quantum gravity theories; matrix models and their applications; and statistical theories
of random surfaces and paths. He is currently sharing a position as a professor at the Niels Bohr Institute
and the Institute for Theoretical Physics, Utrecht
.
Ambjørn has worked with or been acknowledged as an influence by quantum physicists such as Renate Loll
, Fotini Markopoulou, Jerzy Jurkiewicz, and Lee Smolin
.
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
regarded as the primary founder of Causal Dynamical Triangulation Theory (CDT).
Ambjørn began in the early 1990s searching for a physics model that bonded quantum mechanics
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
and relativistic gravity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
in a way that didn't require supersymmetry
Supersymmetry
In particle physics, supersymmetry is a symmetry that relates elementary particles of one spin to other particles that differ by half a unit of spin and are known as superpartners...
. By 1994, he argued a simpler way to represent quantum gravity
Quantum gravity
Quantum gravity is the field of theoretical physics which attempts to develop scientific models that unify quantum mechanics with general relativity...
was to use Lorentzian
Lorentzian
Lorentzian may refer to* Cauchy–Lorentz distribution, also known as the Lorentz distribution, Lorentzian function, or Cauchy distribution* Lorentz transformation* Lorentzian inner product* Lorentzian manifoldThe name Lorentz may refer to*Hendrik Lorentz...
space-time geometry as a framework. His first major publication on the lattice model
Lattice model (physics)
In physics, a lattice model is a physical model that is defined on a lattice, as opposed to the continuum of space or spacetime. Lattice models originally occurred in the context of condensed matter physics, where the atoms of a crystal automatically form a lattice. Currently, lattice models are...
that would become CDT theory was released in 1998. It was then that he and Renate Loll
Renate Loll
Renate Loll is a physicist who works at the , The Netherlands. She received her Ph.D. from , London, in 1989. In 2001 she joined the permanent staff of the ITP, after spending several years at the Max Planck Institute for Gravitational Physics in Golm, Germany...
made triangulation and the causal approach the cornerstones to the lattice gauge theory
Lattice gauge theory
In physics, lattice gauge theory is the study of gauge theories on a spacetime that has been discretized into a lattice. Gauge theories are important in particle physics, and include the prevailing theories of elementary particles: quantum electrodynamics, quantum chromodynamics and the Standard...
.
The theory of Causal Dynamical Triangulations faced harsh scrutiny for some years because most physicists preferred models that required more dimensions
Dimensions
Dimensions is a French project that makes educational movies about mathematics, focusing on spatial geometry. It uses POV-Ray to render some of the animations, and the films are release under a Creative Commons licence....
and a fixed background.
By 2004, Ambjørn's assertion of the benefits to a non-perturbative quantum gravity
Quantum gravity
Quantum gravity is the field of theoretical physics which attempts to develop scientific models that unify quantum mechanics with general relativity...
model regained attention.
As of 2007, Ambjørn continues to research lattice gauge, string, and quantum gravity theories; matrix models and their applications; and statistical theories
Statistical theory
The theory of statistics provides a basis for the whole range of techniques, in both study design and data analysis, that are used within applications of statistics. The theory covers approaches to statistical-decision problems and to statistical inference, and the actions and deductions that...
of random surfaces and paths. He is currently sharing a position as a professor at the Niels Bohr Institute
Niels Bohr Institute
The Niels Bohr Institute is a research institute of the University of Copenhagen. The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics and biophysics....
and the Institute for Theoretical Physics, Utrecht
Utrecht University
Utrecht University is a university in Utrecht, Netherlands. It is one of the oldest universities in the Netherlands and one of the largest in Europe. Established March 26, 1636, it had an enrollment of 29,082 students in 2008, and employed 8,614 faculty and staff, 570 of which are full professors....
.
Ambjørn has worked with or been acknowledged as an influence by quantum physicists such as Renate Loll
Renate Loll
Renate Loll is a physicist who works at the , The Netherlands. She received her Ph.D. from , London, in 1989. In 2001 she joined the permanent staff of the ITP, after spending several years at the Max Planck Institute for Gravitational Physics in Golm, Germany...
, Fotini Markopoulou, Jerzy Jurkiewicz, and Lee Smolin
Lee Smolin
Lee Smolin is an American theoretical physicist, a researcher at the Perimeter Institute for Theoretical Physics, and an adjunct professor of physics at the University of Waterloo. He is married to Dina Graser, a communications lawyer in Toronto. His brother is David M...
.
Sources
- Markopoulou, F., Smolin, L. "Gauge Fixing in Causal Dynamical Triangulations." Perimeter Institute for Theoretical Physics. 23 May 2006.
- 2004 Conference Journal