Annalen der Physik

Cover image for Vol. 522 Issue 7

July 2010

Volume 522, Issue 7

Pages 445–531

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Original Papers
    1. Cover Picture: Ann. Phys. 7/2010

      Article first published online: 17 JUN 2010 | DOI: 10.1002/andp.201090005

  2. Contents

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Original Papers
    1. Contents: Ann. Phys. 7/2010 (pages 445–446)

      Article first published online: 17 JUN 2010 | DOI: 10.1002/andp.201052207

  3. Original Papers

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Original Papers
    1. Scalar Aharonov-Bohm effect in the presence of a topological defect (pages 447–455)

      K. Bakke and C. Furtado

      Article first published online: 17 MAY 2010 | DOI: 10.1002/andp.201000043

      In this paper the scalar Aharonov-Bohm effect for a neutral particle possessing a magnetic dipole moment in the presence of a cosmic string is studied. The authors study the phase shift acquired by the wave function of the neutral particle in the presence of this topological defect, …

    2. Fundamental times, lengths and physical constants: Some unknown contributions by Ettore Majorana (pages 456–466)

      S. Esposito and G. Salesi

      Article first published online: 10 MAY 2010 | DOI: 10.1002/andp.201010454

      The authors review the introduction in physics of the concepts of an elementary space length and of a fundamental time scale, analyzing some related unknown contributions by Ettore Majorana. In particular, they discuss the quasi-Coulombian scattering in presence of a finite length scale, as well as the introduction of an intrinsic (universal) time delay in the expressions for the retarded electromagnetic potentials. …

    3. Probabilistic observables, conditional correlations, and quantum physics (pages 467–519)

      C. Wetterich

      Article first published online: 11 MAY 2010 | DOI: 10.1002/andp.201010451

      Thumbnail image of graphical abstract

      The author discusses the classical statistics of isolated subsystems. Only a small part of the information contained in the classical probability distribution for the subsystem and its environment is available for the description of the isolated subsystem. The “coarse graining of the information” to micro-states implies probabilistic observables. For two-level probabilistic observables only a probability for finding the values one or minus one can be given for any micro-state, while such observables could be realized as classical observables with sharp values on a substate level. …

    4. Reply to da Rocha and Rodrigues' comments on the orientation congruent algebra and twisted forms in electrodynamics (pages 520–523)

      D.G. Demers

      Article first published online: 8 JUN 2010 | DOI: 10.1002/andp.201000045

      The recent claim by da Rocha and Rodrigues that the nonassociative orientation congruent algebra (���� algebra) and native Clifford algebra are incompatible with the Clifford bundle approach is false. The new native Clifford bundle approach, in fact, subsumes the ordinary Clifford bundle one. Associativity is an unnecessarily too strong a requirement for physical applications. Consequently, we obtain a new principle of nonassociative irrelevance for physically meaningful formulas. In addition, the adoption of formalisms that respect the native representation of twisted (or odd) objects and physical quantities is required for the advancement of mathematics, physics, and engineering because they allow equations to be written in sign-invariant form. This perspective simplifies the analysis of, resolves questions about, and ends needless controversies over the signs, orientations, and parities of physical quantities.

    5. Anisotropic distribution of quantum-vacuum momentum density in a moving electromagnetic medium (pages 524–531)

      J.Q. Shen

      Article first published online: 26 MAY 2010 | DOI: 10.1002/andp.201010455

      An isotropic electromagnetic medium becomes gyrotropically anisotropic when it moves, and an anisotropic electromagnetic environment can then be created in this motion-induced anisotropic medium. One of the most remarkable features is that the quantum vacuum in the anisotropic electromagnetic environment exhibits a nonzero electromagnetic momentum density, since the universal symmetry of the vacuum fluctuation field is broken, and the anisotropic quantum vacuum mode structure is produced because of the symmetry breaking. This would give rise to a noncompensation effect among the four vacuum eigenmodes (i.e., the forward and backward propagating modes as well as their respective mutually perpendicular polarized components), and leads to an anisotropic correction to the vacuum momentum in the moving medium. The physical significance and the potential applications of the anisotropic quantum vacuum are discussed. This quantum-vacuum effect may be used to develop sensitive sensor techniques and to design new quantum optical and photonic devices.