Would Bohr be born if Bohm were born before Born?

I discuss a hypothetical historical context in which a Bohm-like deterministic interpretation of the Schrodinger equation could have been proposed before the Born probabilistic interpretation and argue that in such a context the Copenhagen (Bohr) interpretation would probably have never achieved great popularity among physicists.Comment: 5 pages, revised, accepted for publication in Am. J. Phy

Strings, T-duality breaking, and nonlocality without the shortest distance

T-duality of string theory suggests nonlocality manifested as the shortest possible distance. As an alternative, we suggest a nonlocal formulation of string theory that breaks T-duality at the fundamental level and does not require the shortest possible distance. Instead, the string has an objective shape in spacetime at all length scales, but different parts of the string interact in a nonlocal Bohmian manner.Comment: 7 pages, revised, to appear in Eur. Phys. J.

Quantum mechanics: Myths and facts

A common understanding of quantum mechanics (QM) among students and practical users is often plagued by a number of "myths", that is, widely accepted claims on which there is not really a general consensus among experts in foundations of QM. These myths include wave-particle duality, time-energy uncertainty relation, fundamental randomness, the absence of measurement-independent reality, locality of QM, nonlocality of QM, the existence of well-defined relativistic QM, the claims that quantum field theory (QFT) solves the problems of relativistic QM or that QFT is a theory of particles, as well as myths on black-hole entropy. The fact is that the existence of various theoretical and interpretational ambiguities underlying these myths does not yet allow us to accept them as proven facts. I review the main arguments and counterarguments lying behind these myths and conclude that QM is still a not-yet-completely-understood theory open to further fundamental research.Comment: 51 pages, pedagogic review, revised, new references, to appear in Found. Phy

Investigation of zinc stannate synthesis using photoacoustic spectroscopy

Mixtures of ZnO and SnO2 powders, with molar ratio of 2:1, were mechanically activated for 40, 80 and 160 minutes in a planetary ball mill. The resulting powders were compacted into pellets and non-isothermally sintered up to 1200°C with a heating rate of 5°C/min. X-ray diffraction analysis of obtained powders and sintered samples was performed in order to investigate changes of the phase composition. The microstructure of sintered samples was examined by scanning electron microscopy. The photoacoustic phase and amplitude spectra of sintered samples were measured as a function of the laser beam modulating frequency using a transmission detection configuration. Fitting of experimental data enabled determination of photoacoustic properties including thermal diffusivity. Based on the results obtained a correlation between thermal diffusivity and experimental conditions as well the samples microstructure characteristics was discussed.

Fuel poverty and perception on housing and environmental quality in Belgrade's informal settlement Kaluđerica

Informal development is a specific form of urban sprawl and one of the main challenges for the sustainable development of major cities in Serbia. In this paper we examine this phenomenon with regard to the influence of spatial and urban vulnerabilities of the informal settlements on the housing and environmental deprivation, especially in the context of inhabitants' vulnerability to fuel poverty. The empirical research was carried out on the example of Belgrade's suburban settlement Kaluđerica. The statistical analysis of the results has shown that the observed energy characteristics of housing have no relevant influence on households' financial burden of energy expenditure, but that they considerably influence households' perception on thermal comfort. The relation between a limited access to public services and the lack of amenities in the settlement and noted high household expenditure on transport has proved to be a particularly important indicator. Based on the perception on overall life commodities, a poor quality of the environment has been recognized as a key factor of deprivation related to housing

Changes of Structural, Optical and Electrical Properties of Nickel-Manganite Ceramics Induced by Additional Mechanical Activation

Poster presented at the 10th International Conference and Exhibition of the European Ceramic Society, Berlin, June 17-21, 200

Dirichlet boundary conditions in type IIB superstring theory and fermionic T-duality

In this article we investigate the relation between consequences of Dirichlet boundary conditions (momenta noncommutativity and parameters of the effective theory) and background fields of fermionic T-dual theory. We impose Dirichlet boundary conditions on the endpoints of the open string propagating in background of type IIB superstring theory with constant background fields. We showed that on the solution of the boundary conditions the momenta become noncommutative, while the coordinates commute. Fermionic T-duality is also introduced and its relation to noncommutativity is considered. We use compact notation so that type IIB superstring formally gets the form of the bosonic one with Grassman variables. Then momenta noncommutativity parameters are fermionic T-dual fields. The effective theory, the initial theory on the solution of boundary conditions, is bilinear in the effective coordinates, odd under world-sheet parity transformation. The effective metric is equal to the initial one and terms with the effective Kalb-Ramond field vanish

Ecological and phytosociological characteristics of the association Abieti-Fagetum »pannonicum« Rau{ 1969 prov. on Mt. Medvednica (NW Croatia)

The association Abieti-Fagetum »pannonicum« Rau{ 1969 prov. has an invalid name and a still undefined position in a geobotanical and phytosociological sense. In 2000 and 2001 the flora and different habitat factors of 12 plots (50 x 50 m), within the association Abieti- Fagetum s. l. on the central part of Medvednica mountain, were investigated. In all, 119 taxa of vascular plants were recorded. The life form analysis confirmed that Medvednica flora belongs to the moderate continental climate. Canonical correspondence analysis has showed that changes in altitude, pH and inclination have the strongest influence on changes in floristic structure

Charge and spin fractionalization in strongly correlated topological insulators

We construct an effective topological Landau-Ginzburg theory that describes general SU(2) incompressible quantum liquids of strongly correlated particles in two spatial dimensions. This theory characterizes the fractionalization of quasiparticle quantum numbers and statistics in relation to the topological ground-state symmetries, and generalizes the Chern-Simons, BF and hierarchical effective gauge theories to an arbitrary representation of the SU(2) symmetry group. Our main focus are fractional topological insulators with time-reversal symmetry, which are treated as generalizations of the SU(2) quantum Hall effect.Comment: 8 pages, published versio