105 research outputs found
The Master Thesis of Mosh\'e Flato
The genesis and impact of the M.Sc. thesis by Mosh\'e Flato is analysed. In
this connection, the fruitful passage of Mosh\'e in Lyon, capitale mondiale de
la gastronomie, is evoked. Finally, some basic elements for a model in crystal-
field theory are given as a important step on the way opened by Mosh\'e.Comment: 10 pages, Tex file. Contributed paper submitted for the proceedings
of the `Conf\'erence Mosh\'e Flato 1999' held in Dijon (France), 5 - 8
September 1999. The proceedings will be published by Kluwer Academic
Publishers in the series `Mathematical Physics Studies', eds. G. Dito and D.
Sternheimer, founded by the late Professor Mosh\'e Flat
Miscellaneous Physical Applications of Quantum Algebras
Some ideas about phenomenological applications of quantum algebras to physics
are reviewed. We examine in particular some applications of the algebras and to various dynamical systems and to atomic and
nuclear spectroscopy. The lack of a true (unique) - or -quantization
process is emphasized.Comment: 16 pages, Te
Miscellaneous Applications of Quons
This paper deals with quon algebras or deformed oscillator algebras, for
which the deformation parameter is a root of unity. We show the interest of
such algebras for fractional supersymmetric quantum mechanics, angular momentum
theory and quantum information. More precisely, quon algebras are used for (i)
a realization of a generalized Weyl-Heisenberg algebra from which it is
possible to associate a fractional supersymmetric dynamical system, (ii) a
polar decomposition of SU_2 and (iii) a construction of mutually unbiased bases
in Hilbert spaces of prime dimension. We also briefly discuss (symmetric
informationally complete) positive operator valued measures in the spirit of
(iii).Comment: This is a contribution to the Proc. of the 3-rd Microconference
"Analytic and Algebraic Methods III"(June 19, 2007, Prague, Czech Republic),
published in SIGMA (Symmetry, Integrability and Geometry: Methods and
Applications) at http://www.emis.de/journals/SIGMA
On Two Ways to Look for Mutually Unbiased Bases
Two equivalent ways of looking for mutually unbiased bases are discussed in
this note. The passage from the search for d+1 mutually unbiased bases in C(d)
to the search for d(d+1) vectors in C(d*d) satisfying constraint relations is
clarified. Symmetric informationally complete positive-operator-valued measures
are briefly discussed in a similar vein.Comment: three pages to be published in Acta Polytechnica (Czech Technical
University in Prague
The Impact of Giulio Racah on Crystal- and Ligand-field Theories
This paper focuses on the impact of Racah on crystal- and ligand-field
theories, two branches of molecular physics and condensed matter physics
(dealing with ions embedded in aggregates of finite symmetry). The role of
Racah and some of his students in developing a symmetry-adapted weak-field
model for crystal-field theory is examined. Then, we discuss the extension of
this model to a generalized symmetry-adapted weak-field model for ligand-field
theory. Symmetry considerations via the use of the Wigner-Racah algebra for
chains of type SU(2) > G is essential for these weak-field models. Therefore,
the basic ingredients for the Wigner-Racah algebra of a finite or compact group
are reviewed with a special attention paid to the SU(2) group in a SU(2) > G
basis. Finally, as an unexpected application of nonstandard SU(2) bases, it is
shown how SU(2) bases adapted to the cyclic group allow to build bases of
relevance in quantum information
Phase states and coherent states for generalized Weyl-Heisenberg algebras
This paper is concerned with the construction of phase operators, phase
states, vector phase states, and coherent states for a generalized
Weyl-Heisenberg algebra. This polynomial algebra (that depends on real
parameters) is briefly described. The various states are defined on a finite-
or infinite-dimensional space depending on the parameters. This report
constitutes an introduction to three papers published by the authors in J.
Phys. A [43 (2010) 115303 and 45 (2012) 244036] and J. Math. Phys. [52 (2011)
082101]. See these three papers for the relevant references.Comment: 6 pages, The XXIXth International Colloquium on Group-Theoretical
Methods in Physics, Tianjin : China (2012
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