Klaus Fredenhagen (born 1 December 1947) is a German theoretical physicist who works on the mathematical foundations of

quantum field theory In theoretical physics, quantum field theory (QFT) is a theoretical framework that combines classical field theory, special relativity, and quantum mechanics. QFT is used in particle physics to construct physical models of subatomic particles and ...

Biography

Klaus Fredenhagen was born on 1 December 1947 in

Celle Celle () is a town and capital of the district of Celle, in Lower Saxony, Germany. The town is situated on the banks of the river Aller, a tributary of the Weser, and has a population of about 71,000. Celle is the southern gateway to the Lü ...

, a German city in

Lower Saxony Lower Saxony (german: Niedersachsen ; nds, Neddersassen; stq, Läichsaksen) is a German state (') in northwestern Germany. It is the second-largest state by land area, with , and fourth-largest in population (8 million in 2021) among the 16 ...

. He graduated in 1976 from the

University of Hamburg The University of Hamburg (german: link=no, Universität Hamburg, also referred to as UHH) is a public research university in Hamburg, Germany. It was founded on 28 March 1919 by combining the previous General Lecture System ('' Allgemeines Vor ...

under the supervision of Gert Roepstorff and

Rudolf Haag Rudolf Haag (17 August 1922 – 5 January 2016) was a German theoretical physicist, who mainly dealt with fundamental questions of quantum field theory. He was one of the founders of the modern formulation of quantum field theory and he identifie ...

. In 1985 he became a

privatdozent ''Privatdozent'' (for men) or ''Privatdozentin'' (for women), abbreviated PD, P.D. or Priv.-Doz., is an academic title conferred at some European universities, especially in German-speaking countries, to someone who holds certain formal qualific ...

and in 1990 a

full professor Professor (commonly abbreviated as Prof.) is an academic rank at universities and other post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin as a "person who professes". Professors ...

at the second theory institute of the Hamburg University. Since 2013 he has been a

professor emeritus ''Emeritus'' (; female: ''emerita'') is an adjective used to designate a retired chair, professor, pastor, bishop, pope, director, president, prime minister, rabbi, emperor, or other person who has been "permitted to retain as an honorary title ...

and has continued to be active in research.

Scientific career

His research interests are

algebraic quantum field theory Algebraic quantum field theory (AQFT) is an application to local quantum physics of C*-algebra theory. Also referred to as the Haag–Kastler axiomatic framework for quantum field theory, because it was introduced by . The axioms are stated in te ...

and

quantum field theory in curved spacetime In theoretical physics, quantum field theory in curved spacetime (QFTCS) is an extension of quantum field theory from Minkowski spacetime to a general curved spacetime. This theory treats spacetime as a fixed, classical background, while giving ...

. In 1981 he proved the existence of antiparticles in massive quantum field theories without using the CPT-invariance. In 1990 he and Rudolf Haag made important contributions to the understanding of the Hawking radiation of

black hole A black hole is a region of spacetime where gravitation, gravity is so strong that nothing, including light or other Electromagnetic radiation, electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts t ...

s on a rigorous mathematical footing. In 1994, together with

Sergio Doplicher Sergio Doplicher (born 30 December 1940) is an Italian mathematical physicist, who mainly dealt with the mathematical foundations of quantum field theory and quantum gravity. Biography Sergio Doplicher graduated in Physics at the Sapienza Univ ...

and John E. Roberts, he investigated the mathematical foundations of

quantum gravity Quantum gravity (QG) is a field of theoretical physics that seeks to describe gravity according to the principles of quantum mechanics; it deals with environments in which neither gravitational nor quantum effects can be ignored, such as in the vi ...

in terms of the quantum structure of spacetime at the Planck scale. In 1996, together with Romeo Brunetti, he started working on the generalization of the Epstein-

Glaser Glaser is a surname that is derived from the occupation of the glazier, or glass cutter. Notable persons with this surname * Albrecht Glaser (born 1942), German politician * Barney Glaser (born 1930), American sociologist * Benny Glaser (born 1989) ...

renormalization procedure of interacting quantum field theories in curved spacetime using techniques from the microlocal analysis. He is currently working, together with

Detlev Buchholz Detlev Buchholz (born 31 May 1944) is a German theoretical physicist. He investigates quantum field theory, especially in the axiomatic framework of algebraic quantum field theory. Biography Buchholz studied physics in Hannover and Hamburg wher ...

, on a new C*-algebraic approach to interacting quantum field theories.

Honors and awards

In 1987 Klaus Fredenhagen was awarded the physics prize of the Göttingen Academy of Sciences and in 1997 he was Leibniz Professor at the

University of Leipzig Leipzig University (german: Universität Leipzig), in Leipzig in Saxony, Germany, is one of the world's oldest universities and the second-oldest university (by consecutive years of existence) in Germany. The university was founded on 2 Decemb ...

. In December 2017 the workshop ''Quantum Physics meets Mathematics'' was held in honor of his 70th birthday at the University of Hamburg.

Selected publications

Edited books

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Articles

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References

External links

* . * * . * . * * {{DEFAULTSORT:Fredenhagen, Klaus Living people 20th-century German physicists 21st-century German physicists Academic staff of the University of Hamburg 1947 births People from Celle University of Hamburg alumni