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  • 1
    Electronic Resource
    Electronic Resource
    O(2,1)-like little group for spacelike four-momenta and localized light waves in continuous media (1992)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 33 (1992), S. 3190-3196 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: While a light wave travels in a nonvacuum medium with speed less than the speed of light in vacuum, its energy-momentum four-vector is spacelike. Thus the little group for this light wave is locally isomorphic to O(2,1). It is shown that the transformation of this little group produces observable effects on the light wave, in contrast to the case of the E(2)-like little group for photons in vacuum. It is also shown that the little group can be defined for a localized light wave consisting of a superposition of waves with different frequencies traveling in the same direction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.529537
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  • 2
    Electronic Resource
    Electronic Resource
    Space-time geometry of relativistic particles (1990)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 31 (1990), S. 55-60 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: A three-dimensional space-time geometry of relativistic particles is constructed within the framework of the little groups of the Poincaré group. Since the little group for a massive particle is the three-dimensional rotation group, its relevant geometry is a sphere. For massless particles and massive particles in the infinite-momentum limit, it is shown that the geometry is that of a cylinder and a two-dimensional plane. The geometry of a massive particle continuously becomes that of a massless particle as the momentum/mass becomes large. The geometry of relativistic extended particles is also considered. It is shown that the cylindrical geometry leads to the concept of gauge transformations, while the two-dimensional Euclidean geometry leads to a deeper understanding of the Lorentz condition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.528827
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  • 3
    Electronic Resource
    Electronic Resource
    Symmetries of two-mode squeezed states (1993)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 34 (1993), S. 5493-5508 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: It is known that the symmetry of two-mode squeezed states is governed by the group Sp(4) which is locally isomorphic to the O(3,2) de Sitter group. It is shown that this complicated ten-parameter group can be regarded as a product of two three-parameter Sp(2) groups. It is shown also that two coupled harmonic oscillators serve as a physical basis for the symmetry decomposition. It is shown further that the concept of entropy is needed when one of the two modes is not observed. The entropy is zero when the system is uncoupled. The system reaches thermal equilibrium when the entropy becomes maximal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.530318
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  • 4
    Electronic Resource
    Electronic Resource
    E(2)-symmetric two-mode sheared states (1992)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 33 (1992), S. 1237-1246 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: It is noted that the symmetry of two-mode squeezed states of light is governed by the group Sp(4) that is locally isomorphic to O(3,2). This group has subgroups that are locally isomorphic to the two-dimensional Euclidean group. Two-mode states having the E(2) symmetry are constructed. The translation-like transformations of this symmetry group shear the Wigner distribution function defined over the four-dimensional phase space consisting of two pairs of canonical variables. Sheared states are constructed in the Schrödinger picture of quantum mechanics and in the Fock space for photon numbers. It is shown that the Wigner phase-space picture is a convenient representation of quantum mechanics for calculating measurable quantities of the sheared states.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.529701
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  • 5
    Electronic Resource
    Electronic Resource
    Space-time geometry of relativistic particles in four-dimensional phase space (1991)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 32 (1991), S. 1998-2006 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: The Wigner phase-space picture of Dirac's two-oscillator representation of O(3,2) is given. This constitutes a real representation of Sp(4) which allows us to study the symmetry of the O(3,2) de Sitter group using canonical transformations in four-dimensional phase space. It is also possible to study subgroups of O(3,1) in this phase space. The phase-space picture is given for the two-oscillator model of van Dam, Ng, and Biedenharn [Phys. Lett. B 158, 227 (1985)] for the little groups for massive and massless particles. In this formalism, Lorentz transformations can be described in terms of canonical transformations in phase space. It is particularly convenient for studying infinite-momentum/zero-mass limit of the O(3)-like little group for a massive particle. It is shown that the trivial representation of the E(2)-like little group for a massless particle emerges from this limiting process. The origin of gauge degree of freedom is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.529220
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  • 6
    Electronic Resource
    Electronic Resource
    Muscle Characteristics and Meat Tenderness of Cimaterol-fed Lambs (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 59 (1994), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Shear values of loineye muscle from (cimaterol) CIM-fed lambs were 32 and 28% greater than those of controls at 1 and 8 days postmortem. The CIM-fed animals showed lower (p〈0.01) cytochrome oxidase activity, lower (p〈0.01) initial glycogen, and higher (p〈0.05) 24 hr pH in the longissimus and semimembranosus muscles. Intramuscular fat of treated lambs (2%) was lower (p〈0.01) than that of controls (5.1%), whereas muscle protein concentration was greater (p〈0.05). The decreased aerobic capacity, lower intramuscular fat, lower initial glycogen, higher ultimate muscle pH (5.8–6.2) with subsequently reduced postmortem proteolysis and higher protein concentration all appeared to contribute to greater meat toughness of CIM-fed lambs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.1994.tb06891.x
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  • 7
    Electronic Resource
    Electronic Resource
    An investigation of photocurrent generation by squaraine aggregates in monolayer-modified tin oxide (SnO2) electrodes (1994)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 98 (1994), S. 984-988 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100054a039
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  • 8
    Electronic Resource
    Electronic Resource
    A study on the Kerr effect enhancement by the multidielectric layer structure : 35th annual conference on magnetism and magnetic materials (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 5987-5988 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Many types of magneto-optical structures have been investigated to improve the MO Kerr effect. We have studied the enhancement of the MO Kerr effect in the Tb21Fe79 amorphous film having a multidielectric structure in which the TiO2 layer is sandwiched by SiNx layers. The variations of Kerr angle and reflectivity with the thickness of dielectric layer are calculated by using the reiterative formula [M. Mansuripur, G. A. N. Connel, and J. W. Goodman, J. Appl. Phys. 53, 4485 (1982)]. Experiment and simulation results are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.347813
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  • 9
    Electronic Resource
    Electronic Resource
    Low-loss GaAs/AlGaAs optical waveguides and phase modulator on silicon substrate grown by molecular beam epitaxy (1990)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 56 (1990), S. 802-804 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report on the fabrication and the characterization of low-loss, single-mode GaAs/AlGaAs single heterostructure ridge waveguides and a linear electro-optic phase modulator on silicon substrate. The waveguides and the phase modulator were grown by molecular beam epitaxy and were characterized at a 1.3 μm wavelength. The average TE mode propagation loss of 1.24 dB/cm, obtained for a 6-μm-wide ridge waveguide, is the lowest loss so far reported. The measured phase shift efficiency of the phase modulator was 3.5°/V mm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.102668
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  • 10
    Electronic Resource
    Electronic Resource
    Formation of long-lived gas-phase antiprotonic helium atoms and quenching by H 2 (1993)
    [s.l.] : Nature Publishing Group
    Nature 361 (1993), S. 238-240 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] A recent theoretical account7 deals quantitatively with the metastable antiprotonic atom (Fig. 1). The description given below is semiqualitative, but reveals its important properties. A decelerating antiproton is likely to form an exotic atom only when its kinetic energy falls below the helium ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/361238a0
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