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Jan Ambjørn
Jan Ambjørn is a Danish theoretical physicist. He received his PhD in 1980 at the Niels Bohr Institute in Copenhagen, followed by postdoctoral research positions at Caltech and Nordita. He has been employed at the Niels Bohr Institute from 1986, since 1992 as professor in theoretical physics. From 2003 to 2010 he was also a professor at Utrecht University, and since 2012 he has been a professor at Radboud University, both in the Netherlands. Ambjørn has worked on a large number of different topics. As a PhD student he worked together with his adviser P. Olesen on understanding the vacuum structure of QCD, using a model called the Copenhagen Vacuum. Later they developed the theory of magnetism in the electroweak theory. It provides a very simple physical realisation of anti-screening, an effect associated with asymptotically free quantum field theories. Together with B. Durhuus and Jürg Fröhlich he proposed a non-perturbative formulation of the boson string theory, using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. Overview The institute was founded in 1921, as the Institute for Theoretical Physics of the University of Copenhagen, by the Danish theoretical physicist Niels Bohr, who had been on the staff of the University of Copenhagen since 1914, and who had been lobbying for its creation since his appointment as professor in 1916. On the 80th anniversary of Niels Bohr's birth – October 7, 1965 – the Institute officially became the Niels Bohr Institute. Much of its original funding came from the charitable foundation of the Carlsberg Group, Carlsberg brewery, and later from the Rockefeller Foundation. During the 1920s, and 1930s, the institute was the center of the developing disciplines of atomic physics and quantum physics. Physicists from across Europe (and sometimes furthe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utrecht University
Utrecht University (UU; , formerly ''Rijksuniversiteit Utrecht'') is a public university, public research university in Utrecht, Netherlands. Established , it is one of the oldest universities in the Netherlands. In 2023, it had an enrollment of 39,769 students, and employed 8,929 faculty members and staff. More than 400 PhD degrees were awarded and 7,765 scientific articles were published. The university's 2023 budget was €2.8 billion, consisting of €1.157 billion for the university (income from work commissioned by third parties is 319 million euros) and €1.643 billion for the University Medical Center Utrecht. The university's interdisciplinary research targets life sciences, pathways to sustainability, dynamics of youth, and institutions for open societies. Utrecht University is led by the University Board, consisting of Wilco Hazeleger (Rector Magnificus), Anton Pijpers (chair), Margot van der Starre (Vice Chair) and Niels Vreeswijk (Student Assessor). Close ties are h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radboud University
Radboud University (abbreviated as RU, , formerly ) is a public research university located in Nijmegen, Netherlands. RU has seven faculties and more than 24,000 students. Established in 1923, Radboud University has consistently been included in the top 150 of universities in the world by four major university ranking tables. As of 2020, it ranks 105th in the Shanghai Academic Ranking of World Universities. Internationally, RU is known for its strong research output. In 2020, 391 PhD degrees were awarded, and 8,396 scientific articles were published. To bolster the international exchange of academic knowledge, Radboud University joined the Guild of European Research-Intensive Universities in 2016. Among its alumni Radboud University counts 14 Spinoza Prize laureates, 2 Stevin Prize laureates, 1 Nobel Prize laureate, Sir Konstantin Novoselov, and 5 prime ministers of the Netherlands, including the current prime minister Dick Schoof. Other notable alumni include former chair ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jürg Fröhlich
Jürg Martin Fröhlich (born 4 July 1946 in Schaffhausen) is a Swiss mathematician and theoretical physicist. He is best known for introducing rigorous techniques for the analysis of statistical mechanics models, in particular continuous symmetry breaking (infrared bounds), and for pioneering the study of topological phases of matter using low-energy effective field theories. Biography In 1965 Fröhlich began to study mathematics and physics at Eidgenössischen Technischen Hochschule Zürich. In 1969, under Klaus Hepp and Robert Schrader, he attained the Diplom (“Dressing Transformations in Quantum Field Theory”), and in 1972 he earned a PhD from the same institution under Klaus Hepp. After postdoctoral visits to the University of Geneva and Harvard University (with Arthur Jaffe), he took an assistant professorship in 1974 in the mathematics department of Princeton University. From 1978 until 1982 he was a professor at Institut des Hautes Études Scientifiques in Bure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
String Theory
In physics, string theory is a theoretical framework in which the point-like particles of particle physics are replaced by one-dimensional objects called strings. String theory describes how these strings propagate through space and interact with each other. On distance scales larger than the string scale, a string acts like a particle, with its mass, charge, and other properties determined by the vibrational state of the string. In string theory, one of the many vibrational states of the string corresponds to the graviton, a quantum mechanical particle that carries the gravitational force. Thus, string theory is a theory of quantum gravity. String theory is a broad and varied subject that attempts to address a number of deep questions of fundamental physics. String theory has contributed a number of advances to mathematical physics, which have been applied to a variety of problems in black hole physics, early universe cosmology, nuclear physics, and condensed matter ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 vicinity of black holes or similar compact astrophysical objects, as well as in the early stages of the universe moments after the Big Bang. Three of the four fundamental forces of nature are described within the framework of quantum mechanics and quantum field theory: the Electromagnetism, electromagnetic interaction, the Strong interaction, strong force, and the Weak interaction, weak force; this leaves gravity as the only interaction that has not been fully accommodated. The current understanding of gravity is based on Albert Einstein's general theory of relativity, which incorporates his theory of special relativity and deeply modifies the understanding of concepts like time and space. Although general relativity is highly regarded for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hausdorff Dimension
In mathematics, Hausdorff dimension is a measure of ''roughness'', or more specifically, fractal dimension, that was introduced in 1918 by mathematician Felix Hausdorff. For instance, the Hausdorff dimension of a single point is zero, of a line segment is 1, of a square is 2, and of a cube is 3. That is, for sets of points that define a smooth shape or a shape that has a small number of corners—the shapes of traditional geometry and science—the Hausdorff dimension is an integer agreeing with the usual sense of dimension, also known as the topological dimension. However, formulas have also been developed that allow calculation of the dimension of other less simple objects, where, solely on the basis of their properties of scaling and self-similarity, one is led to the conclusion that particular objects—including fractals—have non-integer Hausdorff dimensions. Because of the significant technical advances made by Abram Samoilovitch Besicovitch allowing computation of di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renate Loll
Renate Loll (born 19 June 1962, Aachen) Is a German physicist. She is a Professor in Theoretical Physics at the Institute for Mathematics, Astrophysics and Particle Physics of the Radboud University in Nijmegen, Netherlands. She previously worked at the Institute for Theoretical Physics of Utrecht University. She received her Ph.D. from Imperial College, 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 Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu .... With Jan Ambjørn and Polish physicist Jerzy Jurkiewicz she helped develop a new approach to nonperturbative quantum gravity, quantization of gravity, that of Causal dynamical triangulation, Causal Dynamical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Causal Dynamical Triangulation
Causal dynamical triangulation (CDT), theorized by Renate Loll, Jan Ambjørn and Jerzy Jurkiewicz, is an approach to quantum gravity that, like loop quantum gravity, is background independent. This means that it does not assume any pre-existing arena (dimensional space) but, rather, attempts to show how the spacetime fabric itself evolves. There is evidence that, at large scales, CDT approximates the familiar 4-dimensional spacetime but shows spacetime to be 2-dimensional near the Planck scale, and reveals a fractal structure on slices of constant time. These interesting results agree with the findings of Lauscher and Reuter, who use an approach called Quantum Einstein Gravity, and with other recent theoretical work. Introduction Near the Planck scale, the structure of spacetime itself is supposed to be constantly changing due to quantum fluctuations and topological fluctuations. CDT theory uses a triangulation process which varies dynamically and follows determ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
21st-century Danish Physicists
File:1st century collage.png, From top left, clockwise: Jesus is crucified by Roman authorities in Judaea (17th century painting). Four different men (Galba, Otho, Vitellius, and Vespasian) claim the title of Emperor within the span of a year; The Great Fire of Rome (18th-century painting) sees the destruction of two-thirds of the city, precipitating the empire's first persecution against Christians, who are blamed for the disaster; The Roman Colosseum is built and holds its inaugural games; Roman forces besiege Jerusalem during the First Jewish–Roman War (19th-century painting); The Trưng sisters lead a rebellion against the Chinese Han dynasty (anachronistic depiction); Boudica, queen of the British Iceni leads a rebellion against Rome (19th-century statue); Knife-shaped coin of the Xin dynasty., 335px rect 30 30 737 1077 Crucifixion of Jesus rect 767 30 1815 1077 Year of the Four Emperors rect 1846 30 3223 1077 Great Fire of Rome rect 30 1108 1106 2155 Boudican revolt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Living People
Purpose: Because living persons may suffer personal harm from inappropriate information, we should watch their articles carefully. By adding an article to this category, it marks them with a notice about sources whenever someone tries to edit them, to remind them of WP:BLP (biographies of living persons) policy that these articles must maintain a neutral point of view, maintain factual accuracy, and be properly sourced. Recent changes to these articles are listed on Special:RecentChangesLinked/Living people. Organization: This category should not be sub-categorized. Entries are generally sorted by family name In many societies, a surname, family name, or last name is the mostly hereditary portion of one's personal name that indicates one's family. It is typically combined with a given name to form the full name of a person, although several give .... Maintenance: Individuals of advanced age (over 90), for whom there has been no new documentation in the last ten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
