Photon mass and quantum effects of the Aharonov-Bohm type

The magnetic field due to the photon rest mass $m_{ph}$ modifies the standard results of the Aharonov-Bohm effect for electrons, and of other recent quantum effects. For the effect involving a coherent superposition of beams of particles with opposite electromagnetic properties, by means of a table-top experiment, the limit $m_{ph}x10^{-51}g$ is achievable, improving by 6 orders of magnitude that derived by Boulware and Deser for the Aharonov-Bohm effect.Comment: 5 page

Causal loop quantum cosmology in momentum space

We shall show that it is possible to make a causal interpretation of loop quantum cosmology using the momentum as the dynamical variable. We shall show that one can derive Bohmian trajectories. For a sample cosmological solution with cosmological constant, the trajectory is plotted.Comment: 21 pages, 2 figures. To appear in Int. J. Mod. Phys. D, 200

Conformal Invariance and Wave-Particle Duality

We present a conformally invariant generalized form of the free particle action by connecting the wave and particle aspects through gravity. Conformal invariance breaking is introduced by choosing a particular configurat$ of dynamical variables. This leads to the geometrization of the quantum aspects of matter.Comment: 5 page

Madelung Fluid Model for The Most Likely Wave Function of a Single Free Particle in Two Dimensional Space with a Given Average Energy

We consider spatially two dimensional Madelung fluid whose irrotational motion reduces into the Schr\"odinger equation for a single free particle. In this respect, we regard the former as a direct generalization of the latter, allowing a rotational quantum flow. We then ask for the most likely wave function possessing a given average energy by maximizing the Shannon information entropy over the quantum probability density. We show that there exists a class of solutions in which the wave function is self-trapped, rotationally symmetric, spatially localized with finite support, and spinning around its center, yet stationary. The stationarity comes from the balance between the attractive quantum force field of a trapping quantum potential generated by quantum probability density and the repulsive centrifugal force of a rotating velocity vector field. We further show that there is a limiting case where the wave function is non-spinning and yet still stationary. This special state turns out to be the lowest stationary state of the ordinary Schr\"odinger equation for a particle in a cylindrical tube classical potential.Comment: 19 page

Misleading signposts along the de Broglie-Bohm road to quantum mechanics

Eighty years after de Broglie's, and a little more than half a century after Bohm's seminal papers, the de Broglie--Bohm theory (a.k.a. Bohmian mechanics), which is presumably the simplest theory which explains the orthodox quantum mechanics formalism, has reached an exemplary state of conceptual clarity and mathematical integrity. No other theory of quantum mechanics comes even close. Yet anyone curious enough to walk this road to quantum mechanics is soon being confused by many misleading signposts that have been put up, and not just by its detractors, but unfortunately enough also by some of its proponents. This paper outlines a road map to help navigate ones way.Comment: Dedicated to Jeffrey Bub on occasion of his 65th birthday. Accepted for publication in Foundations of Physics. A "slip of pen" in the bibliography has been corrected -- thanks go to Oliver Passon for catching it

Isolated fungus ball mimicking mucocele or frontal sinus tumour: a diagnostic pitfall

Frontal sinus fungus ball should be considered in the differential diagnosis of chronic, nonspecific forehead symptoms. To evaluate the underlying disease, computed tomography scans should first be performed, followed by magnetic resonance imaging if malignancy is suspected. It is essential to be aware of the possibility of an atypical fungus ball appearance on computed tomography and magnetic resonance imaging scans. If bony destruction and calcification coexist on radiological images, then endoscopic biopsy is an indispensable part of the diagnostic procedure, and should be performed to collect material for both histological and mycological analysis, and to aid surgical planning. In cases of sinus fungus ball, an endoscopic approach for biopsy may be curative

Isolated fungus ball mimicking mucocele or frontal sinus tumour: a diagnostic pitfall

Abstract Objective: To demonstrate the clinical, radiological and diagnostic pitfalls of managing an isolated frontal sinus fungus ball, and to compare with the literature. Material and methods: Retrospective analysis of two cases and literature review. Results: Isolated frontal sinus fungus ball is a rare cause of frontal sinus disease. We present two cases of isolated frontal sinus fungus ball which pre-operatively were suspected to be either a tumour or a mucocele. In both cases, cheesy, clay-like material was found intra-operatively within the frontal sinus, suggesting a fungus ball. Effective treatment included surgical debridement via an exclusively endoscopic or an external approach, variously. Final histopathological and mycological analysis revealed Aspergillus fumigatus. A literature review revealed 20 reported cases of isolated frontal sinus fungus ball, confirming the low prevalence of the disease. Conclusions: Frontal sinus fungus ball should be considered in the differential diagnosis of chronic, nonspecific forehead symptoms. To evaluate the underlying disease, computed tomography scans should first be performed, followed by magnetic resonance imaging if malignancy is suspected. It is essential to be aware of the possibility of an atypical fungus ball appearance on computed tomography and magnetic resonance imaging scans. If bony destruction and calcification coexist on radiological images, then endoscopic biopsy is an indispensable part of the diagnostic procedure, and should be performed to collect material for both histological and mycological analysis, and to aid surgical planning. In cases of sinus fungus ball, an endoscopic approach for biopsy may be curativ

A dynamical time operator in Dirac's relativistic quantum mechanics

A self-adjoint dynamical time operator is introduced in Dirac's relativistic formulation of quantum mechanics and shown to satisfy a commutation relation with the Hamiltonian analogous to that of the position and momentum operators. The ensuing time-energy uncertainty relation involves the uncertainty in the instant of time when the wave packet passes a particular spatial position and the energy uncertainty associated with the wave packet at the same time, as envisaged originally by Bohr. The instantaneous rate of change of the position expectation value with respect to the simultaneous expectation value of the dynamical time operator is shown to be the phase velocity, in agreement with de Broglie's hypothesis of a particle associated wave whose phase velocity is larger than c. Thus, these two elements of the original basis and interpretation of quantum mechanics are integrated into its formal mathematical structure. Pauli's objection is shown to be resolved or circumvented. Possible relevance to current developments in interference in time, in Zitterbewegung like effects in spintronics, grapheme and superconducting systems and in cosmology is noted

Time-like flows of energy-momentum and particle trajectories for the Klein-Gordon equation

The Klein-Gordon equation is interpreted in the de Broglie-Bohm manner as a single-particle relativistic quantum mechanical equation that defines unique time-like particle trajectories. The particle trajectories are determined by the conserved flow of the intrinsic energy density which can be derived from the specification of the Klein-Gordon energy-momentum tensor in an Einstein-Riemann space. The approach is illustrated by application to the simple single-particle phenomena associated with square potentials.Comment: 14 pages, 11 figure

Might EPR particles communicate through a wormhole?

We consider the two-particle wave function of an Einstein-Podolsky-Rosen system, given by a two dimensional relativistic scalar field model. The Bohm-de Broglie interpretation is applied and the quantum potential is viewed as modifying the Minkowski geometry. In this way an effective metric, which is analogous to a black hole metric in some limited region, is obtained in one case and a particular metric with singularities appears in the other case, opening the possibility, following Holland, of interpreting the EPR correlations as being originated by an effective wormhole geometry, through which the physical signals can propagate.Comment: Corrected version, to appears in EP