The Maxwell Electromagnetic Equations and the Lorentz Type Force Derivation—The Feynman Approach Legacy

R. Feynman’s “heretical” approach (Dyson in Am. J. Phys. 58:209–211, 1990; Dyson in Phys. Today 42(2):32–38, 1989) to deriving the Lorentz force based Maxwell electromagnetic equations is revisited, the its complete legacy is argued both by means of the geometric considerations and its deep relation with the vacuum field theory approach devised (Prykarpatsky et al. in Int. J. Theor. Phys. 49:798–820, 2010; Prykarpatsky et al. in Preprint ICTP, 2008, ). Being completely classical, we reanalyze the Feynman’s derivation from the classical Lagrangian and Hamiltonian points of view and construct its nontrivial relativistic generalization compatible with the vacuum field theory approach.     

On Steady Distributions of Kinetic Models of Conservative Economies

We analyze the large-time behavior of various kinetic models for the redistribution of wealth in simple market economies introduced in the pertinent literature in recent years. As specific examples, we study models with fixed saving propensity introduced by Chakraborti and Chakrabarti (Eur. Phys. J. B 17:167–170, 2000), as well as models involving both exchange between agents and speculative trading as considered by Cordier et al. (J. Stat. Phys. 120:253–277, 2005) We derive a sufficient criterion under which a unique non-trivial stationary state exists, and provide criteria under which these steady states do or do not possess a Pareto tail. In particular, we prove the absence of Pareto tails in pointwise conservative models, like the one in (Eur. Phys. J. B 17:167–170, 2000), while models with speculative trades introduced in (J. Stat. Phys. 120:253–277, 2005) develop fat tails if the market is “risky enough”. The results are derived by a Fourier-based technique first developed for the Maxwell-Boltzmann equation (Gabetta et al. in J. Stat. Phys. 81:901–934, 1995; Bisi et al. in J. Stat. Phys. 118(1–2):301–331, 2005; Pareschi and Toscani in J. Stat. Phys. 124(2–4):747–779, 2006) and from a recursive relation which allows to calculate arbitrary moments of the stationary state.     

Large scale synthesis of silicon nanowires

Artificial nanostructures (Samuelson et al., Physica E 21:560–567, 2004; Xia et al., Adv Mater 15:353–389, 2003) show promise for the organization of functional materials (Huck and Samuelson, Nanotechnology 14:NIL_5–NIL_8, 2003) to create nanoelectronic (Mizuta and Oda, Science 279:208–211, 2008) or nano-optical devices (Mazur et al.; Tanemura et al., Synthesis, Optical Properties and Functional Applications of ZnO Nano-materials: A Review, 1–3:58–63, 2008). However, in most manufacturing recipes described so far, nanostructures are synthesized in solution and/or uncontrolled deposition results in random arrangements; this makes it difficult to measure the properties of attached nanodevices or to integrate them with conventionally fabricated microcircuitry. Here, we describe a fully CMOS compatible process technology for mass manufacture of polysilicon nanowires by the CVD (chemical vapor deposition) method. The large scale production of nanowires could successfully be synthesized on silicon (100) substrates. However, the method presented here can successfully be employed with all technologically useful substrates with good adhesion for silicon such as SiO₂, diamond-like carbon or III–V semiconductors. This opens up the possibility for the fabrication of strain-sensitive and defect-sensitive optoelectronic devices on the optimum III–V substrate (Fonstad et al.). Finally, scanning electron microscopy (SEM) was used to characterize the as-synthesized nanowires and energy-filtered transmission electron microscopy (EFTEM) and scanning transmission electron microscopy (STEM) analysis were used to determine the nanowire composition.     

Entropy of Stationary Nonequilibrium Measures of Boundary Driven Symmetric Simple Exclusion Processes

We examine the entropy of stationary nonequilibrium measures of boundary driven symmetric simple exclusion processes. In contrast with the Gibbs–Shannon entropy (Bahadoran in J. Stat. Phys. 126(4–5):1069–1082, 2007; Derrida et al. in J. Stat. Phys. 126(4–5):1083–1108, 2007), the entropy of nonequilibrium stationary states differs from the entropy of local equilibrium states.     

Non-equilibrium Thermodynamics of Piecewise Deterministic Markov Processes

We consider a class of stochastic dynamical systems, called piecewise deterministic Markov processes, with states (x,σ)∈Ω×Γ, Ω being a region in ℝ ^d or the d-dimensional torus, Γ being a finite set. The continuous variable x follows a piecewise deterministic dynamics, the discrete variable σ evolves by a stochastic jump dynamics and the two resulting evolutions are fully-coupled. We study stationarity, reversibility and time-reversal symmetries of the process. Increasing the frequency of the σ-jumps, the system behaves asymptotically as deterministic and we investigate the structure of its fluctuations (i.e. deviations from the asymptotic behavior), recovering in a non Markovian frame results obtained by Bertini et al. (Phys. Rev. Lett. 87(4):040601, 2001; J. Stat. Phys. 107(3–4):635–675, 2002; J. Stat. Mech. P07014, 2007; Preprint available online at , 2008), in the context of Markovian stochastic interacting particle systems. Finally, we discuss a Gallavotti–Cohen-type symmetry relation with involution map different from time-reversal.     

Reexamining the Security of Controlled Quantum Secure Direct Communication by Using Four Particle Cluster States

A controlled quantum secure direct communication protocol (Zhang et al. in Int. J. Theor. Phys. 48:2971–2976, 2009) by using four particle cluster states was proposed recently. Yang et al. presented an attack with fake entangled particles (FEP attack) and gave an improvement (Yang et al. in Int. J. Theor. Phys. 50:395–400, 2010). In this paper, we reexamine the protocol’s security and discover that, Bob can also take a different attack, disentanglement attack, to obtain Alice’s secret message without controller’s permission. Moreover, our attack strategy also works for Yang’s improvement.     

Kinetic Models with Randomly Perturbed Binary Collisions

We introduce a class of Kac-like kinetic equations on the real line, with general random collisional rules which, in some special cases, identify models for granular gases with a background heat bath (Carrillo et al. in Discrete Contin. Dyn. Syst. 24(1):59–81, 2009), and models for wealth redistribution in an agent-based market (Bisi et al. in Commun. Math. Sci. 7:901–916, 2009). Conditions on these collisional rules which guarantee both the existence and uniqueness of equilibrium profiles and their main properties are found. The characterization of these stationary states is of independent interest, since we show that they are stationary solutions of different evolution problems, both in the kinetic theory of rarefied gases (Cercignani et al. in J. Stat. Phys. 105:337–352, 2001; Villani in J. Stat. Phys. 124:781–822, 2006) and in the econophysical context (Bisi et al. in Commun. Math. Sci. 7:901–916, 2009).     

A Macroscopic Model for a System of Swarming Agents Using Curvature Control

In this paper, we study the macroscopic limit of a new model of collective displacement. The model, called PTWA, is a combination of the Vicsek alignment model (Vicsek et al. in Phys. Rev. Lett. 75(6):1226–1229, 1995) and the Persistent Turning Walker (PTW) model of motion by curvature control (Degond and Motsch in J. Stat. Phys. 131(6):989–1021, 2008; Gautrais et al. in J. Math. Biol. 58(3):429–445, 2009). The PTW model was designed to fit measured trajectories of individual fish (Gautrais et al. in J. Math. Biol. 58(3):429–445, 2009). The PTWA model (Persistent Turning Walker with Alignment) describes the displacements of agents which modify their curvature in order to align with their neighbors. The derivation of its macroscopic limit uses the non-classical notion of generalized collisional invariant introduced in (Degond and Motsch in Math. Models Methods Appl. Sci. 18(1):1193–1215, 2008). The macroscopic limit of the PTWA model involves two physical quantities, the density and the mean velocity of individuals. It is a system of hyperbolic type but is non-conservative due to a geometric constraint on the velocity. This system has the same form as the macroscopic limit of the Vicsek model (Degond and Motsch in Math. Models Methods Appl. Sci. 18(1):1193–1215, 2008) (the ‘Vicsek hydrodynamics’) but for the expression of the model coefficients. The numerical computations show that the numerical values of the coefficients are very close. The ‘Vicsek Hydrodynamic model’ appears in this way as a more generic macroscopic model of swarming behavior as originally anticipated.     

Comment on “Quantum Key Distribution and Quantum Authentication Based on Entangled State”

Shi et al. (Phys. Lett. A 281:83–87, 2001) proposed a scheme which allows simultaneous realization of quantum key distribution and quantum authentication. However, this study points out a weakness in Shi et al.’s scheme, in which a malicious user can impersonate a legitimate participant without being detected. Furthermore, an improved scheme is proposed to avoid this weakness.     

A response to Murshed et al., J Nanopart Res (2010) 12:2007–2010

This brief communication provides a response to Murshed et al. (J Nanopart Res 12:2007–2010, 2010). We acknowledge that three of the equations in our original article (Doroodchi et al. J Nanopart Res 11:1501–1507, 2009) contained minor typographical errors. However, we confirm that these misprinted equations have no bearing on the results presented within that article. In addition, we would like to clarify that we do not challenge the methodology of Leong et al. (J Nanopart Res 8:245–254, 2006). Instead, we repeated their analysis using a more general form for the temperature field with continuity imposed across the particle–nanolayer–liquid interfaces and found that the solution reduces to the Renovated-Maxwell model.     

<Emphasis Type="Italic">N</Emphasis>=2 de Sitter Super-symmetry Algebra

It was shown that N=1 super-symmetry algebra can be constructed in de Sitter space (Pahlavan et al. in Phys Lett. B 627:217–223, 2005), through calculation of charge conjugation in the ambient space notation (Moradi et al. in Phys. Lett. B 613:74, 2005; Phys. Lett. B 658:284, 2008). Calculation of N=2 super-symmetry algebra constitutes the main frame of this paper. N=2 super-symmetry algebra was presented in Pilch et al. (Commun. Math. Phys. 98:105, 1985). In this paper, we obtain an alternative N=2 super-symmetry algebra.     

On Consistency of the Quantum-Like Representation Algorithm

In this paper we continue to study so-called “inverse Born’s rule problem”: to construct a representation of probabilistic data of any origin by a complex probability amplitude which matches Born’s rule. The corresponding algorithm—quantum-like representation algorithm (QLRA)—was recently proposed by A. Khrennikov (Found. Phys. 35(10):1655–1693, 2005; Physica E 29:226–236, 2005; Dokl. Akad. Nauk 404(1):33–36, 2005; J. Math. Phys. 46(6):062111–062124, 2005; Europhys. Lett. 69(5):678–684, 2005). Formally QLRA depends on the order of conditioning. For two observables (of any origin, e.g., physical or biological) a and b, b|a- and a|b conditional probabilities produce two representations, say in Hilbert spaces H ^b|a and H ^a|b . In this paper we prove that under “natural assumptions” (which hold, e.g., for quantum observables represented by operators with nondegenerate spectra) these two representations are unitary equivalent. This result proves the consistency of QLRA.     

Neutron halo isomers in stable nuclei and their possible application for the production of low energy, pulsed, polarized neutron beams of high intensity and high brilliance

We propose to search for neutron halo isomers populated via γ-capture in stable nuclei with mass numbers of about A=140–180 or A=40–60, where the 4s _1/2 or 3s _1/2 neutron shell model state reaches zero binding energy. These halo nuclei can be produced for the first time with new γ-beams of high intensity and small band width (≤0.1%) achievable via Compton back-scattering off brilliant electron beams, thus offering a promising perspective to selectively populate these isomers with small separation energies of 1 eV to a few keV. Similar to single-neutron halo states for very light, extremely neutron-rich, radioactive nuclei (Hansen et al. in Annu. Rev. Nucl. Part. Sci. 45:591–634, 1995; Tanihata in J. Phys. G., Nucl. Part. Phys. 22:158–198, 1996; Aumann et al. in Phys. Rev. Lett. 84:35, 2000), the low neutron separation energy and short-range nuclear force allow the neutron to tunnel far out into free space much beyond the nuclear core radius. This results in prolonged half-lives of the isomers for the γ-decay back to the ground state in the 100 ps-μs range. Similar to the treatment of photodisintegration of the deuteron, the neutron release from the neutron halo isomer via a second, low-energy, intense photon beam has a known much larger cross section with a typical energy threshold behavior. In the second step, the neutrons can be released as a low-energy, pulsed, polarized neutron beam of high intensity and high brilliance, possibly being much superior to presently existing beams from reactors or spallation neutron sources.     

Comparative Similarity in Branching Space-Times

My aim in this paper is to investigate the notions of comparative similarity definable in the framework of branching space-times. A notion of this kind is required to give a rigorous Lewis-style semantics of space-time counterfactuals. In turn, the semantical analysis is needed to decide whether the recently proposed proofs of the non-locality of quantum mechanics are correct. From among the three notions of comparative similarity I select two which appear equally good as far as their intuitiveness and algebraic properties are concerned. However, the relations are not transitive, and thus cannot be used in the semantics proposed by Lewis (J. Philos. Log. 2:418–446, 1973), which requires transitivity. Yet they are adequate for the account of Lewis (J. Philos. Log. 10:217–234, 1981).     

Quantum-Like Model for Decision Making Process in?Two Players Game A Non-Kolmogorovian Model

In experiments of games, players frequently make choices which are regarded as irrational in game theory. In papers of Khrennikov (Information Dynamics in Cognitive, Psychological and Anomalous Phenomena. Fundamental Theories of Physics, Kluwer Academic, Norwell, 2004; Fuzzy Sets Syst. 155:4–17, 2005; Biosystems 84:225–241, 2006; Found. Phys. 35(10):1655–1693, 2005; in QP-PQ Quantum Probability and White Noise Analysis, vol. XXIV, pp. 105–117, 2009), it was pointed out that statistics collected in such the experiments have “quantum-like” properties, which can not be explained in classical probability theory. In this paper, we design a simple quantum-like model describing a decision-making process in a two-players game and try to explain a mechanism of the irrational behavior of players. Finally we discuss a mathematical frame of non-Kolmogorovian system in terms of liftings (Accardi and Ohya, in Appl. Math. Optim. 39:33–59, 1999).     

Electro-optic coefficient and wavelength dispersion in sillenite crystals

We report on the measurement of the electro-optic or Pockels coefficient of titanosillenite crystals and show that there is no sensible wavelength dispersion, at least in the explored 510–650 nm wavelength range. This result is in close agreement with a previous paper by Papazoglou et al.: Appl. Phys. B 65, 499–503 (1997) for titanosillenites but in contradiction with a recent paper by Efremidis et al.: Appl. Phys. B 95, 467–473 (2009) reporting on a large dispersion for sillenite crystals. We stress on the fact that photoinduced space-charge electrical polarization may be at the origin of a misleading apparent wavelength dependence of the electro-optic coefficient.     

Singular Harmonic Maps and Applications to General Relativity

The study of axially symmetric stationary multi-black-hole configurations and the force between co-axially rotating black holes involves, as a first step, an analysis on the “boundary regularity” of the so-called reduced singular harmonic maps. We carry out this analysis by considering those harmonic maps as solutions to some homogeneous divergence systems of partial differential equations with singular coefficients. Our results extend previous works by Weinstein (Comm Pure Appl Math 43:903–948, 1990; Comm Pure Appl Math 45:1183–1203, 1992) and by Li and Tian (Manu Math 73(1):83–89, 1991; Commun Math Phys 149:1–30, 1992; Differential geometry: PDE on manifolds, vol 54, pp. 317–326, 1993). This paper is based on the Ph.D. thesis of the author (Singular harmonic maps into hyperbolic spaces and applications to general relativity, PhD thesis, The State University of New Jersey, Rutgers, 2009).     

Planar superstrate for dual-frequency RHCP-LHCP array

Patch antennas are low profile, lightweight and most suitable for aerospace and mobile applications. In recent years Fabry–Pérot cavities and meta-surfaces have been used as superstrates to improve the radiation performance of planar antennas (Saenz et al., IEEE Trans. Antennas Propag. 56(4), 2008; Iriarte et al., IEEE Trans. Antennas Propag. 57(1), 2009) such as directivity, mutual coupling on array configuration and bandwidth. These structures usually work for a single polarization and frequency band, while an increasing number of applications require multifrequency operation. In this paper a Fabry–Pérot cavity that works with dual-polarized and dual-frequency patch antennas (rectangular patch excited orthogonally) is proposed in order to design high-directivity dual-frequency RHCP-LHCP Arrays.