Quantum Theory viewed from Wigner Phase Space

• Wolfgang P. Schleich (Institute für Quantenphysik, Universitat Ulm)

Room: Ceremonial Hall (Díszterem) Eugene Paul Wigner’s formulation [1, 2] of quantum mechanics in phase space is completely equivalent to the ones by Werner Heisenberg, Erwin Schrödinger or Richard Feynman but offers many insights into the inner workings of quantum theory usually hidden behind the opaque curtain of the respective formalism. In the present talk we review some of them having led to the construction of focusing wave packets in free space [3], or the astonishing properties [4] of s-waves giving rise to measures of entanglement [5] based on the negative parts of the Wigner function, and tunneling [6] analyzed from phase space making contact with Unruh radiation. References [1] E.P. Wigner, On the quantum correction for thermodynamic equilibrium, Phys. Rev. 40, 749-759 (1932) [2] W.P. Schleich, Quantum Optics in Phase Space, (VCH-Wiley, Weinheim, 2001) [3] I. Bialynicki-Birula, M.A. Cirone, J.P. Dahl, M. Fedorov, and W.P. Schleich, In- and outbound spreading of a free-particle s-wave, Phys. Rev. Lett. 89, 060404 (2002) [4] J.P. Dahl, S. Varro, A. Wolf, and W.P. Schleich, Wigner functions of s waves, Phys. Rev. A 75, 052107 (2007) [5] J.P. Dahl, H. Mack, A. Wolf, and W.P. Schleich, Entanglement versus negative domains of Wigner functions, Phys. Rev. A 74, 042323 (2006) [6] D.M. Heim, W.P. Schleich, P.M. Alsing, J.P. Dahl, and S. Varro, Tunneling of an energy eigenstate through a parabolic barrier viewed from Wigner phase space, Phys. Lett. A 377, 1822-1825 (2013)

Quantum RMS Deviation and Heisenbergs Error‐Disturbance Relation

• Paul Busch

Room: Ceremonial Hall (Díszterem) It has been claimed in recent research publications that Heisenberg’s idea of an accuracy-disturbance trade-off in quantum measurements has been theoretically and experimentally falsified. Here we analyze this claim and show that it is based on a combination of two factors: (a) a restricted perspective on measurement uncertainty relations that focuses on state-dependent measures of error and disturbance rather than considering them figures of merit for measuring devices; (b) the use of a generalization of Gauss’ root-mean-square deviation that is based on the problematic concept of noise operator. We present an alternative operationally significant quantum generalization of root-mean- square deviation and using this we obtain a valid formulation of a Heisenberg-type error- disturbance relation for position and momentum.

Effective Image Recognition using High-Order Symmetry of Correlated Orbital Angular Momentum (OAM) States

• Alexander V. Sergienko

Room: Ceremonial Hall (Díszterem) A major contribution of Wigner's work was the introduction of group theory to study both the dynamics and the classification of states in quantum mechanics. The use of rotational symmetry to study the properties of angular momentum eigenstates is particularly associated with him. Following along a similar path, it is shown here that advances in the study of entangled two-photon states allow the rapid detection of rotational symmetries in complex macroscopic objects, and that knowledge of this symmetry structure can allow identification, and in some circumstances reconstruction, of the object. This suggests some possible future applications.

Wigner crystals - New realizations of an old idea

• Jenő Sólyom (Wigner RCP of the HAS)

Room: Ceremonial Hall (Díszterem)

The role of Wigner's 1939 Representation Theory in ongoing Foundational Changes of Quantum Field Theory

• Bert Schroer

Room: Ceremonial Hall (Díszterem) Presently quantum field theory is undergoing significant changes which started with the solution of an old problem: the quantum field theory behind the third positive energy Wigner representation class ("infinite spin")in terms of of string-localized generating fields. This in turn led to foundational changes for the other two classes: the m>0 and the m=0 finite helicity class The stringlocal description of these two classes leads among other things to the extension of renormalizability for any spin and the "adiabatic equivalence principle" makes sure that the physical content is the same as in the nonrenormalizable pointlike description i.e. stringlocal fields play the role of a different "field coordinatization" of the same QFT. The special case m>0, s=1 amounts to a Hilbert space analog of the BRST operator gauge description in Krein space in which the subalgebra of pointlike fields coincides with the gauge invariant observables. The stringlike approach leads to new insights into the Higgs mechanism and confinement. Last but not least it reveals that the noncompact localization properties of the third Wigner class matter as those which astrophysicists ascribe to dark matter.

Relativistic Wigner functions

• Iwo Białynicki-Birula (Polish Academy of Sciences, Warsaw)

Room: Ceremonial Hall (Díszterem) Owing to the processes of particle creation and annihilation relativistic quantum mechanics does not exist as a consistent theory and it must be replaced by quantum field theory. Nevertheless the original construction of Wigner (and Szilard) can be extended in a natural manner to quantum field theory just by replacing wave functions by the field operators [1]. The expectation value in a one-particle state of such an object reduces in the nonrelativistc approximation to the standard Wigner function. Of course, in full quantum field theory the evolution equation for the Wigner function involves higher order functions that are built from products of more than two field operators and the hierarchy of such equations does not close. However, when the coupling to the external field plays the dominant role and the mutual interaction can be neglected, one obtains the evolution equation similar to the transport equation for the standard Wigner function that in some cases can be solved analytically. One important application of this construction is the description of electron-positron pair creation by an applied electromagnetic field. Every quantum field theory allows for the construction of the Wigner function from field operators but for the electromagnetic field (and also for other bosonic fields) there is also an entirely different construction that leads to a Wigner functional. The arguments of this functional are not points in the phase space but the electric and magnetic fields. Still, this functional shares many properties with the good old Wigner function and it enables one to learn something new about the properties of the quantized electromagnetic field. In particular, this construction gives a new insight into the statistical properties of the electromagnetic field at finite temperature. References: [1] I. Bialynicki-Birula, P. Gornicki and J. Rafelski, Phys. Rev. D 44, 1825 (1991).

Bell's inequalities: "From Einstein, Bell, Wigner, to entangled quantum bits: a new quantum era"

• Alain Aspect (Institut d'Optique, Palaiseau)

Room: Ceremonial Hall (Díszterem)

Nuclear Physics at GSI and FAIR

• Horst Stöcker

Room: Ceremonial Hall (Díszterem) The international Facility for Antiproton and Ion Research in Europe (FAIR) is the largest fundamental science facility under construction worldwide. FAIR has been founded by Finland, France, Germany, India, Poland, Romania, Russia, Slovenia and Sweden. From 2018 onwards, FAIR will provide unique opportunities for cutting-edge research in nuclear, hadron and particle physics, atomic and anti-matter science, high density plasmas and applications in condensed matter, biology and the bio-medical- and material sciences. A global community of 3000 scientists from 51 countries prepare for outstanding research in the APPA, CBM, NUSTAR and PANDA detector collaborations. A cutting edge accelerator complex with eight storage and superconducting synchrotron rings and several linacs is constructed with the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany.

Neutron Stars, Black Holes, and Gamma Ray Bursts: three events with Eugen Wigner in Princeton

• Remo Ruffini

Room: Ceremonial Hall (Díszterem)

Megnyitó/Opening: Wigner öröksége Room: Ceremonial Hall (Díszterem)

Wigner Jenő: Sokoldalú tudós a viharos 20. században

• István Hargittai (Budapesti Műszaki és Gazdaságtudományi Egyetem)

Room: Ceremonial Hall (Díszterem) Wigner Jenő Budapestről indult, Németországban vegyészmérnöki diplomat szerzett, majd kiváló elméleti fizikus lett. A náci hatalomátvétel után az Egyesült Államokban kötött ki, ahol elméleti fizikusként és a világ első nukleáris mérnökeként is működött. Segítette új hazáját és a szabad világot az első atomreaktorok megépítésében, a 2. világháború, majd a hidegháború megnyerésében. Alkalmazta a csoportelméletet és általában szimmetriameggondolásokat a kémiai reakciók leírásában és az atomfizikában. 1963-ban fizikai Nobel-díjjal tüntették ki. Az előadás bemutatja Wigner kontinenseken és diszciplínákon keresztülívelő munkásságát és emberközelségbe hozza ezt a különleges tudóst. Eugene P. Wigner Jenő moved from Budapest to Germany, graduated as chemical engineer, and became an internationally renowned theoretical physicist. After the Nazi takeover, he moved to the US where he worked as a professor of theoretical physics and the world’s first nuclear engineer. He assisted his new home country in developing the atomic bombs, winning World War II and the Cold War. He applied group theory and symmetry considerations in the description of chemical reactions and in atomic physics. In 1963, he received the Nobel Prize in Physics. This public lecture presents Wigner’s activities that spanned continents and scientific disciplines and bring this great scientist into human proximity. The presentation will be copiously illustrated with captions in English and will include a segment from a video conversation of Wigner with Clarence Larson in 1986 in English. Irodalom/Bibliography: Hargittai István, Az öt világformáló marslakó (Budapest: Vince Kiadó, 2006). Istvan Hargittai, The Martians of Science: Five Physicists Who Changed the Twentieth Century (New York: Oxford University Press, 2006 hardcover; 2008 softcover).

Multi-entanglement of a Single Particle

• Helmuth Rauch

Room: Ceremonial Hall (Díszterem)

Poincaré Sphere and a Unified Picture of Wigners Little Groups

• Young Suh Kim

Room: Ceremonial Hall (Díszterem)

E. P. Wigner and the Shaping of a National Laboratory: From the Manhattan Project to the Present

• Malcolm STOCKS

Room: Ceremonial Hall (Díszterem) The modern Oak Ridge National Laboratory (ORNL), which is the largest of the US Department of Energy (DOE) research laboratories, had its origins in the Manhattan Project as a pilot-scale facility for the production and separation of plutonium. Although E. P. Wigner spent only a little more than a year as research director of what was then known as Clinton Laboratories, his influence on the development of ORNL extended far beyond that period. Indeed, it was Wigner who laid the foundations for many of the signature strengths that ORNL boasts today, including nuclear energy, materials and chemical sciences, neutron scattering, life sciences and arguably computational science. When discussing Wigner’s lasting impact on ORNL, it is useful to consider a series of somewhat distinct periods: Wigner pre-Clinton – the Manhattan Project and the Metallurgical Laboratory at the University of Chicago; Wigner at Clinton – his role in developing and implementing a vision for a post-war civilian nuclear research laboratory underpinned by fundamental science; Wigner after Clinton – his continuing engagement with ORNL as consultant to and friend of ORNL’s longest serving director, Alvin Weinberg; and Wigner as ORNL’s “patron saint” and the inspiration for the establishment of the prestigious Wigner Fellowships for outstanding early-career researchers and most recently for the establishment of the “Eugene P. Wigner Distinguished Lecture Series,” which brings Nobel Laureates and internationally known industrial and technical leaders to the laboratory. In dealing with these periods we will refer to much original material that will convey Wigner’s most enduring legacy: that not only is basic science a matter of joy to the individual scientist, but it can and should contribute to the well-being of humanity.

The First and Best Reactor Engineer

• László Koblinger
• József Rónaky

Room: Ceremonial Hall (Díszterem)

Fractional and Majorana Fermions (The physics of Dirac zero-energy modes)

• Roman Jackiw

Room: Ceremonial Hall (Díszterem)

Carbon from Red Giants to White Dwarfs The Breit-Wigner Formula, the Wigner Limit, and the Wigner-Seitz Radius

• Michael Wiescher

Room: Ceremonial Hall (Díszterem) This talk will discuss on to key reactions during post-main sequence stellar evolution. Both the radiative capture reactions 12C(α,)16O and the fusion reaction 12C+12C affect the nucleosynthesis of carbon in our universe. The role of these reactions will be discussed and recent results for the reaction cross sections will be analyzed in the context of nuclear structure and reaction models formulated by Eugene Wigner. The impact of the present prediction on quiescent late stellar evolution and cataclysmic explosions will be discussed.

Broken Symmetries and the Higgs Boson

• Dezső Horváth (Wigner RCP of the HAS)

Room: Ceremonial Hall (Díszterem) The Standard Model, the theory of particle physics, based on global and local gauge symmetries, was established 40 years ago and it seems to describe all experimental data very well. All of its elementary particles were identified and studied long ago apart from the Higgs boson. The two main experiments of the Large Hadron Collider at CERN, CMS and ATLAS in 2012 observed a new boson with properties close to those predicted for the Standard Model Higgs boson. The latest LHC results imply that the new boson is indeed the Standard Model Higgs boson and thereby prove the validity of the Brout-Englert-Higgs mechanism of spontaneous symmetry breaking. François Englert and Peter Higgs received the 2013 Nobel Prize in physics. There are several questions yet concerning the possible theoretical significance of the mass of the new particle.

Eugene Wigner: A Gedanken Pioneer of the Second Quantum Revolution

• Anton Zeilinger (Universität Wien, Wien, Austria)

Room: Ceremonial Hall (Díszterem) Eugene Wigner pointed out very interesting consequences of Quantum Physics in elegant gedanken experiments. Due to technical progress these gedanken experiments have become real experiments and contribute to the development of novel concepts in quantum information science, often called the second quantum revolution.