TAMM-DANCOFF DEFORMATION OF BOSONIC OSCILLATOR ALGEBRAS

The Tamm-Dancoff (TD) deformation of the boson oscillator incorporates a high energy cutoff in its spectrum. It is found that one can obtain a similar deformation of any generalized bosonic oscillator algebra. The Hopf (or ‘quantum’) algebraic aspects of the TD-deformation are discussed. Examples are given.

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ON ESTIMATING THE HIGH-ENERGY CUTOFF IN THE X-RAY SPECTRA OF BLACK HOLES VIA REFLECTION SPECTROSCOPY

The Astrophysical Journal ◽

10.1088/2041-8205/808/2/l37 ◽

2015 ◽

Vol 808 (2) ◽

pp. L37 ◽

Cited By ~ 25

Author(s):

Javier A. García ◽

Thomas Dauser ◽

James F. Steiner ◽

Jeffrey E. McClintock ◽

Mason L. Keck ◽

...

Keyword(s):

Black Holes ◽

High Energy ◽

Reflection Spectroscopy ◽

X Ray ◽

Energy Cutoff

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A simple optical system delivering a tunable micrometer pink beam that can compensate for heat-induced deformations

Journal of Synchrotron Radiation ◽

10.1107/s1600577515006566 ◽

2015 ◽

Vol 22 (4) ◽

pp. 930-935 ◽

Cited By ~ 1

Author(s):

Ruben Reininger ◽

Zunping Liu ◽

Gilles Doumy ◽

Linda Young

Keyword(s):

Optical System ◽

Heat Load ◽

Optical Element ◽

High Energy ◽

Angle Of Incidence ◽

Optical Elements ◽

Source Distance ◽

Energy Cutoff ◽

Working Distance ◽

Photon Source

The radiation from an undulator reflected from one or more optical elements (usually termed `pink-beam') is used in photon-hungry experiments. The optical elements serve as a high-energy cutoff and for focusing purposes. One of the issues with this configuration is maintaining the focal spot dimension as the energy of the undulator is varied, since this changes the heat load absorbed by the first optical element. Finite-element analyses of the power absorbed by a side water-cooled mirror exposed to the radiation emitted by an undulator at the Advanced Photon Source (APS) and at the APS after the proposed upgrade (APSU) reveals that the mirror deformation is very close to a convex cylinder creating a virtual source closer to the mirror than the undulator source. Here a simple optical system is described based on a Kirkpatrick–Baez pair which keeps the focus size to less than 2 µm (in the APSU case) with a working distance of 350 mm despite the heat-load-induced change in source distance. Detailed ray tracings at several photon energies for both the APS and APSU show that slightly decreasing the angle of incidence on the mirrors corrects the change in the `virtual' position of the source. The system delivers more than 70% of the first undulator harmonic with very low higher-orders contamination for energies between 5 and 10 keV.

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ON A ONE-PARAMETER FAMILY OF EXOTIC SUPERSPACES IN TWO DIMENSIONS

Modern Physics Letters A ◽

10.1142/s0217732391003730 ◽

1991 ◽

Vol 06 (35) ◽

pp. 3239-3250 ◽

Cited By ~ 3

Author(s):

MURAT GÜNAYDIN

Keyword(s):

Two Dimensions ◽

Parameter Family ◽

Oscillator Algebra ◽

Jordan Superalgebras ◽

Special Values ◽

Finite Dimensional ◽

Operator Realization ◽

The One ◽

Conformal Superalgebras ◽

Bosonic Oscillator

Using Jordan algebraic techniques we define and study a family of exotic superspaces in two dimensions with two bosonic and two fermionic coordinates. They are defined by the one-parameter family of Jordan superalgebras JD (2/2)α. For two special values of α the JD (2/2)α can be realized in terms of a single fermionic or a single bosonic oscillator, respectively. For other values of α it can be interpreted as defining an exotic oscillator algebra. The derivation, reduced structure and Möbius superalgebras of JD (2/2)α are identified with the rotation, Lorentz and finite-dimensional conformal superalgebras of the corresponding superspaces. The conformal superalgebras turn out to be the superalgebras D(2,1;α) with the even subgroup SO(2,2)×SU(2) . We give an explicit differential operator realization of the actions of D(2,1;α) on these superspaces.

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On Measuring the Variation of High-energy Cutoff in Active Galactic Nuclei

The Astrophysical Journal ◽

10.3847/1538-4357/aacf92 ◽

2018 ◽

Vol 863 (1) ◽

pp. 71 ◽

Cited By ~ 2

Author(s):

Ji-Xian Zhang ◽

Jun-Xian Wang ◽

Fei-Fan Zhu

Keyword(s):

Active Galactic Nuclei ◽

Galactic Nuclei ◽

High Energy ◽

Energy Cutoff

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Ultrahigh Energy Cosmic-ray Accelerators

Symposium - International Astronomical Union ◽

10.1017/s0074180900163053 ◽

2000 ◽

Vol 195 ◽

pp. 303-310

Author(s):

A. V. Olinto

Keyword(s):

Angular Distribution ◽

Neutron Star ◽

Cosmic Rays ◽

Cosmic Ray ◽

High Energy ◽

Ultrahigh Energy ◽

Recent Proposal ◽

Alternative Models ◽

Isotropic Distribution ◽

Energy Cutoff

The surprising lack of a high energy cutoff in the cosmic ray spectrum at the highest energies, together with an apparently isotropic distribution of arrival directions, have strongly challenged most models proposed for the acceleration of ultrahigh energy cosmic rays. Young neutron star winds may be able to explain the mystery. We discuss this recent proposal after summarizing the observational challenge and plausible acceleration sites. Young neutrons star winds differ from alternative models in the predictions for composition, spectrum, and angular distribution, which will be tested in future experiments.

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QUANTUM ANTI-DE SITTER SPACE AT ROOTS OF UNITY

International Journal of Modern Physics B ◽

10.1142/s0217979200002041 ◽

2000 ◽

Vol 14 (22n23) ◽

pp. 2499-2501

Author(s):

HAROLD STEINACKER

Keyword(s):

Hilbert Spaces ◽

Scalar Fields ◽

De Sitter Space ◽

High Energy ◽

Roots Of Unity ◽

De Sitter ◽

Algebra Of Functions ◽

Energy Cutoff ◽

Star Structure

An algebra of functions on q-deformed Anti-de Sitter space [Formula: see text] with star-structure is defined for roots of unity, which is covariant under Uq(so(2, D-1)). The scalar fields have an intrinsic high-energy cutoff, and arise most naturally on products of the quantum AdS space with a classical sphere. Hilbert spaces of scalar fields are constructed.

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Evaluation of Monte Carlo tools for high energy atmospheric physics

Geoscientific Model Development ◽

10.5194/gmd-9-3961-2016 ◽

2016 ◽

Vol 9 (11) ◽

pp. 3961-3974 ◽

Cited By ~ 7

Author(s):

Casper Rutjes ◽

David Sarria ◽

Alexander Broberg Skeltved ◽

Alejandro Luque ◽

Gabriel Diniz ◽

...

Keyword(s):

Monte Carlo ◽

Gamma Ray ◽

High Energy ◽

Atmospheric Physics ◽

Computational Performance ◽

Electron Positron ◽

Custom Made ◽

Electric And Magnetic Fields ◽

Energy Cutoff ◽

High Energy Particles

Abstract. The emerging field of high energy atmospheric physics (HEAP) includes terrestrial gamma-ray flashes, electron–positron beams and gamma-ray glows from thunderstorms. Similar emissions of high energy particles occur in pulsed high voltage discharges. Understanding these phenomena requires appropriate models for the interaction of electrons, positrons and photons of up to 40 MeV energy with atmospheric air. In this paper, we benchmark the performance of the Monte Carlo codes Geant4, EGS5 and FLUKA developed in other fields of physics and of the custom-made codes GRRR and MC-PEPTITA against each other within the parameter regime relevant for high energy atmospheric physics. We focus on basic tests, namely on the evolution of monoenergetic and directed beams of electrons, positrons and photons with kinetic energies between 100 keV and 40 MeV through homogeneous air in the absence of electric and magnetic fields, using a low energy cutoff of 50 keV. We discuss important differences between the results of the different codes and provide plausible explanations. We also test the computational performance of the codes. The Supplement contains all results, providing a first benchmark for present and future custom-made codes that are more flexible in including electrodynamic interactions.

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Completeness and Nonclassicality of Coherent States for Generalized Oscillator Algebras

Advances in Mathematical Physics ◽

10.1155/2017/7168592 ◽

2017 ◽

Vol 2017 ◽

pp. 1-15 ◽

Cited By ~ 9

Author(s):

Kevin Zelaya ◽

Oscar Rosas-Ortiz ◽

Zurika Blanco-Garcia ◽

Sara Cruz y Cruz

Keyword(s):

Coherent States ◽

Beam Splitter ◽

Delta Function ◽

Oscillator Algebra ◽

Closure Relation ◽

Classical Analog ◽

Delta Distribution ◽

Nonclassical Properties ◽

Generalized Oscillator ◽

Oscillator Algebras

The purposes of this work are (1) to show that the appropriate generalizations of the oscillator algebra permit the construction of a wide set of nonlinear coherent states in unified form and (2) to clarify the likely contradiction between the nonclassical properties of such nonlinear coherent states and the possibility of finding a classical analog for them since they are P-represented by a delta function. In (1) we prove that a class of nonlinear coherent states can be constructed to satisfy a closure relation that is expressed uniquely in terms of the Meijer G-function. This property automatically defines the delta distribution as the P-representation of such states. Then, in principle, there must be a classical analog for them. Among other examples, we construct a family of nonlinear coherent states for a representation of the su(1,1) Lie algebra that is realized as a deformation of the oscillator algebra. In (2), we use a beam splitter to show that the nonlinear coherent states exhibit properties like antibunching that prohibit a classical description for them. We also show that these states lack second-order coherence. That is, although the P-representation of the nonlinear coherent states is a delta function, they are not full coherent. Therefore, the systems associated with the generalized oscillator algebras cannot be considered “classical” in the context of the quantum theory of optical coherence.

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