Michel Davier (born 6 March 1942) is a French physicist.
Graduate of the École normale supérieure de Saint-Cloud (science), he was Director of the Laboratory of Linear Accelerator in Orsay from 1985 to 1994. Winner of the Gentner-Kastler Prize in 1994, he was elected a member of the French Academy of Sciences (Physics section) in 1996. [1] He was appointed senior member of the Institut universitaire de France in 1991 for a five-year term, [2] renewed in 1996. [3]
He has been teaching physics since 1975 at the Paris-Sud University at the Centre scientifique d'Orsay.
Originally from Ambérieu-en-Bugey (Ain), Michel Davier studied at the Lycée Lalande in Bourg-en-Bresse, at the École Normale d'instituteurs in the same city, and then at the École Normale d'instituteurs in Lyon. After a year of preparatory classes at the Lycée Chaptal in Paris in 1960–61, he entered the École normale supérieure de Saint-Cloud where he obtained a degree in physics and chemistry. Admitted to the first agrégation in physics in 1965, he chose to focus on higher education and research in elementary particle physics. Having joined the Laboratory of Linear Accelerator (LAL) founded in Orsay by the École Normale Supérieure as an assistant at the University of Paris-Sud, he did his doctoral work on the photoproduction of vector mesons at Stanford University in California at the Stanford Linear Accelerator Center (SLAC), which he defended in 1969 in Orsay. After a two-year stay at the European Centre for Nuclear Research (CERN) in Geneva, he joined Stanford University and SLAC as an assistant professor, then associate professor in 1973 where he conducted hadronic diffusion experiments. He returned to France in 1975 to take up the professorship left vacant by the untimely death of André Lagarrigue. He launched a research program on electron-positron annihilation at the highest energies available at the PETRA collider installed at the DESY laboratory in Hamburg. He is one of the founders of the ALEPH experiment that continues this research at CERN on the LEP collider from 1989, providing precision measurements that will establish the Standard Model of Fundamental Interactions. In 2001, he joined the international collaboration that operates the BABAR detector at SLAC to launch an original precision measurement program. In parallel with his activities in particle physics, he strongly supports the Franco-Italian Virgo project for the research of gravitational waves and welcomed Alain Brillet's team to the LAL in 1991. He actively participates in the construction of the interferometer and data analysis by creating his own group.
He directed the Linear Accelerator Laboratory from 1985 to 1993. Senior member of the Institut Universitaire de France since 1991, corresponding member of the French Academy of Sciences in 1994, he was elected member in 1996. He has been a member of numerous international scientific councils: SLAC (Stanford), LAL (Orsay), CERN (Geneva), DESY (Hamburg), LNF (Frascati), IHEP (Beijing), KEK (Tokyo), APPEC (Europe), LIGO (Caltech, MIT, Hanford, Livingston), Scientific Guidelines Committee (SPC, CERN), National Committee and CNRS Scientific Council (2001–05), Helmholtz Gemeinschaft (Berlin).
The dual aspect of university education, at the University of Paris-Sud, the École Normale Supérieure and the École Polytechnique, and the training of young researchers represents an important investment in Michel Davier's career. He has actively supervised many doctoral theses. In this field, he has maintained a privileged relationship with China since 1988 through close collaboration with the Institute of High Energy Physics (IHEP, Beijing), for the training of Chinese doctoral students and postdoctoral fellows in Orsay, many of whom are now professors and scientific leaders in China.
Michel Davier's research has led to significant advances in the physics of strong and electroweak interactions through the construction and operation of large detectors, CELLO in Hamburg, ALEPH at CERN and BABAR at SLAC:
The construction, development and analysis of the Virgo interferometer data involved a colossal effort through international collaboration in which the group founded by Michel Davier at the LAL took a significant part:
The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. Two large observatories were built in the United States with the aim of detecting gravitational waves by laser interferometry. These observatories use mirrors spaced four kilometers apart which are capable of detecting a change of less than one ten-thousandth the charge diameter of a proton.
The tau, also called the tau lepton, tau particle, tauon or tau electron, is an elementary particle similar to the electron, with negative electric charge and a spin of 1/2. Like the electron, the muon, and the three neutrinos, the tau is a lepton, and like all elementary particles with half-integer spin, the tau has a corresponding antiparticle of opposite charge but equal mass and spin. In the tau's case, this is the "antitau". Tau particles are denoted by the symbol
τ−
and the antitaus by
τ+
.
Albert Fert is a French physicist and one of the discoverers of giant magnetoresistance which brought about a breakthrough in gigabyte hard disks. Currently, he is an emeritus professor at Paris-Saclay University in Orsay, scientific director of a joint laboratory between the Centre national de la recherche scientifique and Thales Group, and adjunct professor at Michigan State University. He was awarded the 2007 Nobel Prize in Physics together with Peter Grünberg.
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Quantum metrology is the study of making high-resolution and highly sensitive measurements of physical parameters using quantum theory to describe the physical systems, particularly exploiting quantum entanglement and quantum squeezing. This field promises to develop measurement techniques that give better precision than the same measurement performed in a classical framework. Together with quantum hypothesis testing, it represents an important theoretical model at the basis of quantum sensing.
The Virgo interferometer is a large Michelson interferometer designed to detect gravitational waves predicted by general relativity. It is located in Santo Stefano a Macerata, near the city of Pisa, Italy. The instrument's two arms are three kilometres long, housing its mirrors and instrumentation inside an ultra-high vacuum.
Gravitational-wave astronomy is an emerging field of science, concerning the observations of gravitational waves to collect relatively unique data and make inferences about objects such as neutron stars and black holes, events such as supernovae, and processes including those of the early universe shortly after the Big Bang.
Louis Michel (1923–1999) was a French mathematical physicist at the Institut des Hautes Études Scientifiques (IHÉS). He was born in Roanne, in the Loire department in central France, on 4 May 1923, and died in Bures-sur-Yvette (Essonne), in the Île-de-France region, on 30 December 1999.
Alessandra Buonanno is an Italian-American theoretical physicist and director at the Max Planck Institute for Gravitational Physics in Potsdam. She is the head of the "Astrophysical and Cosmological Relativity" department. She holds a research professorship at the University of Maryland, College Park, and honorary professorships at the Humboldt University in Berlin, and the University of Potsdam. She is a leading member of the LIGO Scientific Collaboration, which observed gravitational waves from a binary black-hole merger in 2015.
André Neveu is a French physicist working on string theory and quantum field theory who coinvented the Neveu–Schwarz algebra and the Gross–Neveu model.
Jean Zinn-Justin is a French theoretical physicist.
Jean-Michel Raimond is a French physicist working in the field of quantum mechanics.
The first direct observation of gravitational waves was made on 14 September 2015 and was announced by the LIGO and Virgo collaborations on 11 February 2016. Previously, gravitational waves had been inferred only indirectly, via their effect on the timing of pulsars in binary star systems. The waveform, detected by both LIGO observatories, matched the predictions of general relativity for a gravitational wave emanating from the inward spiral and merger of a pair of black holes of around 36 and 29 solar masses and the subsequent "ringdown" of the single resulting black hole. The signal was named GW150914. It was also the first observation of a binary black hole merger, demonstrating both the existence of binary stellar-mass black hole systems and the fact that such mergers could occur within the current age of the universe.
GW 170817 was a gravitational wave (GW) signal observed by the LIGO and Virgo detectors on 17 August 2017, originating from the shell elliptical galaxy NGC 4993. The signal was produced by the last moments of a binary pair of neutron stars' inspiral process, ending with their merger. It is the first GW observation that has been confirmed by non-gravitational means. Unlike the five previous GW detections—which were of merging black holes, and thus not expected to produce a detectable electromagnetic signal—the aftermath of this merger was seen across the electromagnetic spectrum by 70 observatories on 7 continents and in space, marking a significant breakthrough for multi-messenger astronomy. The discovery and subsequent observations of GW 170817 were given the Breakthrough of the Year award for 2017 by the journal Science.
PyCBC is an open source software package primarily written in the Python programming language which is designed for use in gravitational-wave astronomy and gravitational-wave data analysis. PyCBC contains modules for signal processing, FFT, matched filtering, gravitational waveform generation, among other tasks common in gravitational-wave data analysis.
Florent Krzakala is a French physicist and applied mathematician, currently a professor at EPFL. His research focuses on the resolution of theoretical problems in physics, computer science, machine learning, statistics and signal processing using mathematical tools inspired by the field of statistical physics.
Lisa Barsotti is a research scientist at the Massachusetts Institute of Technology Kavli Institute.
Pierre Binétruy was a French theoretical physicist, known for his research on cosmology, gravitational waves, strong nuclear interactions, and supersymmetry.