Results for "L. Persano"

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Control of photon transport properties in nanocomposite nanowiresMar 25 2016Active nanowires and nanofibers can be realized by the electric-field induced stretching of polymer solutions with sufficient molecular entanglements. The resulting nanomaterials are attracting an increasing attention in view of their application in a ... More
3D photo-responsive optical devices manufactured by advanced printing technologiesApr 12 2019Photonic components responsive to external optical stimuli are attracting increasing interest, because their properties can be manipulated by light with fast switching times, high spatial definition, and potentially remote control. These aspects can be ... More
3D printing of optical materials: an investigation of the microscopic propertiesJul 09 20183D printing technologies are currently enabling the fabrication of objects with complex architectures and tailored properties. In such framework, the production of 3D optical structures, which are typically based on optical transparent matrices, optionally ... More
Surface-enhanced Raman spectroscopy in 3D electrospun nanofiber mats coated with gold nanorodsJul 27 2015Mar 15 2016Nanofibers functionalized by metal nanostructures and particles are exploited as effective flexible substrates for SERS analysis. Their complex three-dimensional structure may provide Raman signals enhanced by orders of magnitude compared to untextured ... More
Environmental Noise and Nonlinear Relaxation in Biological SystemsOct 18 2011Dec 17 2011We analyse the effects of environmental noise in three different biological systems: (i) mating behaviour of individuals of \emph{Nezara viridula} (L.) (Heteroptera Pentatomidae); (ii) polymer translocation in crowded solution; (iii) an ecosystem described ... More
Polymer nanofibers as novel light-emitting sources and lasing materialNov 29 2013Polymer micro- and nano-fibers, made of organic light-emitting materials with optical gain, show interesting lasing properties. Fibers with diameters from few tens of nm to few microns can be fabricated by electrospinning, a method based on electrostatic ... More
Optimization of electrospinning techniques for the realization of nanofiber plastic lasersMar 25 2016Electrospinning technologies for the realization of active polymeric nanomaterials can be easily up-scaled, opening perspectives to industrial exploitation, and due to their versatility they can be employed to finely tailor the size, morphology and macroscopic ... More
Noise influence on electron dynamics in semiconductors driven by a periodic electric fieldOct 09 2008Studies about the constructive aspects of noise and fluctuations in different non-linear systems have shown that the addition of external noise to systems with an intrinsic noise may result in a less noisy response. Recently, the possibility to reduce ... More
External noise effects on the electron velocity fluctuations in semiconductorsOct 06 2008We investigate the modification of the intrinsic carrier noise spectral density induced in low-doped semiconductor materials by an external correlated noise source added to the driving high-frequency periodic electric field. A Monte Carlo approach is ... More
Electrospun light-emitting nanofibers as building blocks for photonics and electronicsSep 04 2013Nanomaterials made of active fibers have the potential to become new functional components of light-emitting sources in the visible and near-IR range, lasers, and electronic devices
Doping dependence of spin dynamics of drifting electrons in GaAs bulksAug 25 2010Jun 17 2012We study the effect of the impurity density on lifetimes and relaxation lengths of electron spins in the presence of a static electric field in a n-type GaAs bulk. The transport of electrons and the spin dynamics are simulated by using a semiclassical ... More
Computational homogenization of fibrous piezoelectric materialsMay 13 2014Jul 27 2015Flexible piezoelectric devices made of polymeric materials are widely used for micro- and nano-electro-mechanical systems. In particular, numerous recent applications concern energy harvesting. Due to the importance of computational modeling to understand ... More
Enhancement of electron spin lifetime in GaAs crystals: the benefits of dichotomous noiseNov 26 2013Nov 28 2013The electron spin relaxation process in n-type GaAs crystals driven by a fluctuating electric field is investigated. Two different sources of fluctuations are considered: (i) a symmetric dichotomous noise and (ii) a Gaussian correlated noise. Monte Carlo ... More
Evolutionary dynamics of imatinib-treated leukemic cells by stochastic approachNov 17 2008The evolutionary dynamics of a system of cancerous cells in a model of chronic myeloid leukemia (CML) is investigated by a statistical approach. Cancer progression is explored by applying a Monte Carlo method to simulate the stochastic behavior of cell ... More
Enhancement of the lifetime of metastable states in Er-doped Si nanocrystals by external coloured noiseJul 08 2014Oct 01 2014The changes in the lifetime of a metastable energy level in Er-doped Si nanocrystals in the presence of an external source of colored noise are analyzed for different values of noise intensity and correlation time. Exciton dynamics is simulated by a set ... More
A multiscale-multiphysics strategy for numerical modeling of thin piezoelectric sheetsOct 03 2014Flexible piezoelectric devices made of polymeric materials are widely used for micro- and nano-electro-mechanical systems. In particular, numerous recent applications concern energy harvesting. Due to the importance of computational modeling to understand ... More
Temperature dependence of spin depolarization of drifting electrons in n-type GaAs bulksMar 10 2010Dec 17 2011The influence of temperature and transport conditions on the electron spin relaxation in lightly doped n-type GaAs semiconductors is investigated. A Monte Carlo approach is used to simulate electron transport, including the evolution of spin polarization ... More
Finite Local Models for the GHZ ExperimentSep 18 2012Some years ago Szab\'o and Fine proposed a {\it local} hidden variable theory for the GHZ experiment based on the assumption that "the detection efficiency is not (only) the effect of random errors in the detector equipment, but it is a more fundamental ... More
Controlled atmosphere electrospinning of organic nanofibers with improved light emission and waveguiding propertiesOct 20 2015Nov 16 2015Electrospinning in controlled nitrogen atmosphere is developed for the realization of active polymer nanofibers. Fibers electrospun under controlled atmospheric conditions are found to be smoother and more uniform than samples realized by conventional ... More
New insights into electron spin dynamics in the presence of correlated noiseDec 02 2011Dec 24 2011The changes of the spin depolarization length in zinc-blende semiconductors when an external component of correlated noise is added to a static driving electric field are analyzed for different values of field strength, noise amplitude and correlation ... More
Relaxation of Electron Spin during High-Field Transport in GaAs BulkMay 28 2011Dec 17 2011A semiclassical Monte Carlo approach is adopted to study the multivalley spin depolarization of drifting electrons in a doped n-type GaAs bulk semiconductor, in a wide range of lattice temperature ($40<T_L<300$ K) and doping density ($10^{13}<n<10^{16}$cm$^{-3}$). ... More
Sub-ms dynamics of the instability onset of electrospinningApr 10 2015May 01 2015Electrospun polymer jets are imaged for the first time at an ultra-high rate of 10,000 frames per second, investigating the process dynamics, and the instability propagation velocity and displacement in space. The polymer concentration, applied voltage ... More
Multifunctional polymer nanofibers: UV emission, optical gain, anisotropic wetting and high hydrophobicity for next flexible excitation sourcesSep 24 2015Nov 16 2015The use of UV light sources is highly relevant in many fields of science, being directly related to all those detection and diagnosis procedures which are based on fluorescence spectroscopy. Depending on the specific application, UV light-emitting materials ... More
Electrostatic mechanophores in tuneable light-emitting piezo-polymer nanowiresJun 02 2017Electromechanical coupling through piezoelectric polymer chains allows the emission of organic molecules in active nanowires to be tuned. This effect is evidenced by highly bendable arrays of counter-ion dye-doped nanowires made of a poly(vinylidenefluoride) ... More
Shear piezoelectricity in poly(vinylidenefluoride-co-trifluoroethylene): full piezotensor coefficients by molecular modeling, biaxial transverse response, and use in suspended energy-harvesting nanostructuresJul 04 2016The intrinsic flexible character of polymeric materials also causes remarkable strain deformations along directions perpendicular to the applied stress. Here the biaxial response in the shear piezoelectricity of polyvinylidenefluoride copolymers is analyzed ... More
Cooperativity in the enhanced piezoelectric response of polymer nanowiresOct 30 2014Feb 25 2015We provide a detailed insight into piezoelectric energy generation from arrays of polymer nanofibers. For sake of comparison, we firstly measure individual poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF-TrFe)) fibers at well-defined levels of compressive ... More
High Performance Piezoelectric Devices Based on Aligned Arrays of Nanofibers of Poly[(vinylidenefluoride-co-trifluoroethylene]Sep 27 2013Multifunctional capability, flexible design, rugged lightweight construction, and self-powered operation are desired attributes for electronics that directly interface with the human body or with advanced robotic systems. For these and related applications, ... More
Metal-Enhanced Near-Infrared Fluorescence by Micropatterned Gold NanocagesSep 24 2015Nov 16 2015In metal-enhanced fluorescence (MEF), the localized surface plasmon resonances of metallic nanostructures amplify the absorption of excitation light and assist in radiating the consequent fluorescence of nearby molecules to the far-field. This effect ... More
Physically transient photonics: random vs. distributed feedback lasing based on nanoimprinted DNAOct 08 2014Nov 07 2014The authors report on a room-temperature nanoimprinted, DNA-based distributed feedback (DFB) laser operating at 605 nm. The laser is made of a pure DNA host matrix doped with gain dyes. At high excitation densities, the emission of the untextured dye-doped ... More
Low-defectiveness exfoliation of MoS2 nanoparticles and their embedment in hybrid light-emitting polymer nanofibersNov 17 2018Molybdenum disulfide (MoS2) has been attracting extraordinary attention for its intriguing optical, electronic and mechanical properties. Here we demonstrate hybrid, organic-inorganic light-emitting nanofibers based on MoS2 nanoparticle dopants obtained ... More
Diverse regimes of mode intensity correlation in nanofiber random lasers through nanoparticle dopingDec 27 2017Random lasers are based on disordered materials with optical gain. These devices can exhibit either intensity or resonant feedback, relying on diffusive or interference behaviour of light, respectively, which leads to either coupling or independent operation ... More
Electrospun Conjugated Polymer/Fullerene Hybrid Fibers: Photoactive Blends, Conductivity through Tunnelling-AFM, Light-Scattering, and Perspective for Their Use in Bulk-Heterojunction Organic Solar CellsJan 26 2018Hybrid conjugated polymer/fullerene filaments based on MEH-PPV/PVP/PCBM are prepared by electrospinning, and their properties assessed by scanning electron, atomic and lateral force, tunnelling, and confocal microscopy, as well as by attenuated total ... More
Classification of 6-dimensional real Drinfeld doublesFeb 21 2002Mar 27 2002Starting from the classification of real Manin triples done in a previous paper we look for those that are isomorphic as 6-dimensional Lie algebras with the ad-invariant form used for construction of the Manin triples. We use several invariants of the ... More
Poisson-Lie T-plurality of three-dimensional conformally invariant sigma modelsMar 16 2004May 18 2004Starting from the classification of 6-dimensional Drinfeld doubles and their decomposition into Manin triples we construct 3-dimensional Poisson-Lie T-dual or more precisely T-plural sigma models. Of special interest are those that are conformally invariant. ... More
Reply to Comment on "Statistical mechanics of developable ribbons"Nov 09 2011Starostin and van der Heijden [arXiv:1111.2029] question the validity of the results reported in our Letter [Phys. Rev. Lett. 104, 238104 (2010)] regarding the existence of spontaneous helical structure in finite-temperature developable ribbons. According ... More
Multistability of free spontaneously-curved anisotropic stripsApr 20 2011Dec 07 2011Multistable structures are objects with more than one stable conformation, exemplified by the simple switch. Continuum versions are often elastic composite plates or shells, such as the common measuring tape or the slap bracelet, both of which exhibit ... More
VZ Velorum: 116 years of a Mira starJun 01 2006Using the Harvard College Observatory Photographic Plate Collection and recent CCD observations by the ASAS project we have reconstructed the light variations of the southern pulsating red giant star VZ Velorum between 1890 and early 2006. Contrary to ... More
Results on D+-->lv and Ds+-->lv decays at Charm factoryMay 07 2013Jun 07 2013In this article, we reviewed the results on D+-->lv and Ds+-->lv decays at Charm factory.
Wireless Josephson Junction Arrays as Tunable Metamaterials: Inducing Discrete Frequency Steps with Microwave RadiationJan 23 2015We report low temperature, microwave transmission measurements on a new switchable and tunable class of nonlinear metamaterials. A wireless two dimensional array of Josephson junctions (JJ) is probed as a metamaterial where each plaquette in the array ... More
Covariant derivative expansion of the heat kernelSep 14 2004Nov 02 2004Using the technique of labeled operators, compact explicit expressions are given for all traced heat kernel coefficients containing zero, two, four and six covariant derivatives, and for diagonal coefficients with zero, two and four derivatives. The results ... More
The method of covariant symbols in curved space-timeJun 08 2006Sep 11 2006Diagonal matrix elements of pseudodifferential operators are needed in order to compute effective Lagrangians and currents. For this purpose the method of symbols is often used, which however lacks manifest covariance. In this work the method of covariant ... More
On the cascade approach to the quantum multiscattering problemMay 17 2002Sep 04 2002The multiscattering problem is studied in the matrix density formalism. We study how to isolate the quasi-classical degrees of freedom in order to connect with a cascade approach. The different problems that arise, as well as their possible solutions, ... More
Temperature dependence of the anomalous effective action of fermions in two and four dimensionsJul 29 1998Oct 05 1998The temperature dependence of the anomalous sector of the effective action of fermions coupled to external gauge and pseudo-scalar fields is computed at leading order in an expansion in the number of Lorentz indices in two and four dimensions. The calculation ... More
Theory of charge fluctuations and domain relocation times in semiconductor superlatticesDec 07 2004Shot noise affects differently the nonlinear electron transport in semiconductor superlattices depending on the strength of the coupling among the superlattice quantum wells. Strongly coupled superlattices can be described by a miniband Boltzmann-Langevin ... More
New AdS(3) x G/H compactifications of chiral IIB supergravityMar 13 2000May 30 2000We present a new class of solutions of D=10, N=2 chiral supergravity. A nonvanishing background for the field strength G_{MNR} of the complex two-form triggers AdS_3 x M_7 compactifications, where M_7 is a 7-dimensional compact manifold. When M_7 is a ... More
Detailed analysis of quantum phase transitions within the $u(2)$ algebraOct 13 2009We analyze in detail the quantum phase transitions that arise in models based on the $u(2)$ algebraic description for bosonic systems with two types of scalar bosons. First we discuss the quantum phase transition that occurs in hamiltonians that admix ... More
Recent Results on $\psip$ Decays at BesMay 16 2005Recent results on $\psip$ decays, including 10 Vector + Pseudoscalar (VP) modes and $p\bar{p}\pi^0(\eta)$, are reported with $14\times10^6$ $\psip$ events collected with the BESII detector. Cross sections and form factors for $e^+e^- \to \wpi$, $\rho\eta$, ... More
Statistical consistency of quantum-classical hybridsJan 20 2012After formulating a no-go theorem for perfect quantum-classical hybrid systems, a new consistency requirement based on standard statistical considerations is noted. It is shown that such requirement is not fulfilled by the mean-field approach, nor by ... More
Derivative expansion of the heat kernel in curved spaceJun 13 2007Jul 02 2007The heat kernel in curved space-time is computed to fourth order in a strict expansion in the number of covariant derivatives. The computation is made for arbitrary non abelian gauge and scalar fields and for the Riemann connection in the coordinate sector. ... More
Phase space localization of antisymmetric functionsNov 05 2002Upper and lower bounds are written down for the minimum information entropy in phase space of an antisymmetric wave function in any number of dimensions. Similar bounds are given when the wave function is restricted to belong to any of the proper subspaces ... More
On the uniqueness of the expected stress-energy tensor in renormalizable field theoriesMar 15 1999Sep 17 1999It is argued that the ambiguity introduced by the renormalization in the effective action of a four-dimensional renormalizable quantum field theory is at most a local polynomial action of canonical dimension four. The allowed ambiguity in the expected ... More
Direct construction of the effective action of chiral gauge fermions in the anomalous sectorApr 14 2008Jul 25 2008The anomaly implies an obstruction to a fully chiral covariant calculation of the effective action in the abnormal parity sector of chiral theories. The standard approach then is to reconstruct the anomalous effective action from its covariant current. ... More
The induced Chern-Simons term at finite temperatureJan 09 2002It is argued that the derivative expansion is a suitable method to deal with finite temperature field theory, if it is restricted to spatial derivatives only. Using this method, a simple and direct calculation is presented for the radiatively induced ... More
The Effect of Weak Gravitational Lensing on the Angular Distribution of Gamma-Ray BurstsJun 10 1996If Gamma-Ray Bursts (GRBs) are cosmologically distributed standard candles and are associated with the luminous galaxies, then the observed angular distribution of all GRBs is altered due to weak gravitational lensing of bursts by density inhomogeneities. ... More
Expansion of a Bose-Einstein Condensate in an atomic waveguideNov 15 2001The expansion of a Bose-Einstein condensate in an atomic waveguide is analyzed. We study different regimes of expansion, and identify a transient regime between one-dimensional and three-dimensional dynamics, in which the properties of the condensate ... More
On the active Ornstein-Uhlenbeck particlesMay 13 2019Active Ornstein-Uhlenbeck particles (AOUPs) are overdamped particles in an interaction potential subject to external Ornstein-Uhlenbeck noises. They can be transformed into a system of underdamped particles under additional velocity dependent forces and ... More
Constraints on star formation theories from the Serpens molecular cloud and protoclusterJul 10 2002We have mapped the large-scale structure of the Serpens cloud core using moderately optically thick (13CO(1--0) and CS(2--1)) and optically thin tracers (C18O(1--0), C34S(2--1), and N2H+(1--0)), using the 16-element focal plane array operating at a wavelength ... More
Classification of Poisson-Lie T-dual models with two-dimensional targetsOct 16 2001Dec 20 2001Four-dimensional Manin triples and Drinfeld doubles are classified and corresponding two-dimensional Poisson-Lie T-dual sigma models on them are constructed. The simplest example of a Drinfeld double allowing decomposition into two nontrivially different ... More
Statistical Mechanics of Developable RibbonsFeb 24 2010Jun 11 2010We investigate the statistical mechanics of long developable ribbons of finite width and very small thickness. The constraint of isometric deformations in these ribbon-like structures that follows from the geometric separation of scales introduces a coupling ... More
A bracket polynomial for graphsAug 25 2008Jan 14 2009A knot diagram has an associated looped interlacement graph, obtained from the intersection graph of the Gauss diagram by attaching loops to the vertices that correspond to negative crossings. This construction suggests an extension of the Kauffman bracket ... More
Chapman-Enskog method and synchronization of globally coupled oscillatorsJun 12 2000Jul 10 2000The Chapman-Enskog method of kinetic theory is applied to two problems of synchronization of globally coupled phase oscillators. First, a modified Kuramoto model is obtained in the limit of small inertia from a more general model which includes ``inertial'' ... More
A Dynamical Cross-over Regime in the Transmission and Reflection Spectra of Evanescent Waves with 2D Arrays of Josephson JunctionsFeb 18 2013A dynamical cross-over regime is revealed when exposing a classical two-dimensional ordered Josephson junction (JJ) array to evanescent waves and tuning the incident microwave power. At the lowest possible temperature for these experiments, 1.1 K, and ... More
The invariant factor of the chiral determinantJul 10 2008The coupling of spin 0 and spin 1 external fields to Dirac fermions defines a theory which displays gauge chiral symmetry. Quantum mechanically, functional integration of the fermions yields the determinant of the Dirac operator, known as the chiral determinant. ... More
Derivative expansion for the effective action of chiral gauge fermions. The abnormal parity componentDec 19 2000Mar 01 2001Explicit exact formulas are presented, for the leading order term in a strict chiral covariant derivative expansion, for the abnormal parity component of the effective action of two- and four-dimensional Dirac fermions in presence of scalar, pseudo-scalar, ... More
Representation of Complex ProbabilitiesJul 19 1996Let a ``complex probability'' be a normalizable complex distribution $P(x)$ defined on $\R^D$. A real and positive probability distribution $p(z)$, defined on the complex plane $\C^D$, is said to be a positive representation of $P(x)$ if $\langle Q(x)\rangle_P ... More
Gibbs sampling of complex valued distributionsOct 30 2015Sep 26 2016A new technique is explored for the Monte Carlo sampling of complex-valued distributions. The method is based on a heat bath approach where the conditional probability is replaced by a positive representation of it on the complex plane. Efficient ways ... More
Existence of positive representations for complex weightsJun 29 2007The necessity of computing integrals with complex weights over manifolds with a large number of dimensions, e.g., in some field theoretical settings, poses a problem for the use of Monte Carlo techniques. Here it is shown that very general complex weight ... More
Derivative expansion for the effective action of chiral gauge fermions. The normal parity componentDec 19 2000Mar 01 2001Explicit exact formulas are presented, up to fourth order in a strict chiral covariant derivative expansion, for the normal parity component of the Euclidean effective action of even-dimensional Dirac fermions. The bosonic background fields considered ... More
Parity breaking in 2+1 dimensions and finite temperatureFeb 11 1998Mar 17 1999An expansion in the number of spatial covariant derivatives is carried out to compute the $\zeta$-function regularized effective action of 2+1-dimensional fermions at finite temperature in an arbitrary non-Abelian background. The real and imaginary parts ... More
Absence of classical and quantum mixingSep 15 1995It is shown, under mild assumptions, that classical degrees of freedom dynamically coupled to quantum ones do not inherit their quantum fluctuations. It is further shown that, if the assumptions are strengthen by imposing the existence of a canonical ... More
An alternative approach to the static spherically symmetric vacuum global solution to the Einstein's equationsJun 19 2018Sep 12 2018We propose an alternative description of the Schwarzschild black hole based on the requirement that the solution be static not only outside the horizon but also inside it. As a consequence of this assumption, we are led to a change of signature implying ... More
Population Models With Delay in Dynamic EnvironmentJan 05 2006Mar 15 2006We study the combined effects of periodically varying carrying capacity and survival rates on the fish population in the ocean (sea). We introduce the Getz type delay differential equation model with a control parameter which describes how fish are harvested. ... More
Optical Calibration For Jefferson Lab HKS SpectrometerNov 04 2005In order to accept very forward angle scattering particles, Jefferson Lab HKS experiment uses an on-target zero degree dipole magnet. The usual spectrometer optics calibration procedure has to be modified due to this on-target field. This paper describes ... More
Skew braces and the Yang-Baxter equationNov 10 2015Mar 16 2016Braces were introduced by Rump to study non-degenerate involutive set-theoretic solutions of the Yang-Baxter equation. We generalize Rump's braces to the non-commutative setting and use this new structure to study not necessarily involutive non-degenerate ... More
On compositions of d.c. functions and mappingsJun 05 2007A d.c. (delta-convex) function on a normed linear space is a function representable as a difference of two continuous convex functions. We show that an infinite dimensional analogue of Hartman's theorem on stability of d.c. functions under compositions ... More
Bounds on the Quenched Pressure and Main Eigenvalue of the Ruelle Operator for Brownian Type PotentialsMar 02 2016Jun 23 2016In this paper we consider a random potential derived from the Brownian motion. We obtain upper and lower bounds for the expected value of the main eigenvalue of the associated Ruelle operator and for its quenched topological pressure. We also exhibit ... More
Supersymmetric domain wall x G/H solutions of IIB supergravityApr 23 20011-brane nonmaximally supersymmetric solutions of D=10 chiral supergravity are discussed. In the dual frame, their near brane geometry is the product of a 3-dimensional domain wall spacetime and a 7-dimensional homogeneous Einstein space G/H.
Hawking Radiation and Back-ReactionMar 20 1992The puzzles of black hole evaporation can be studied in the simplified context of 1+1 dimensional gravity. The semi-classical equations of Callan, Giddings, Harvey and Strominger provide a consistent description of the evaporation process which we describe ... More
Minimal surfaces bounded by elastic linesAug 02 2011May 30 2012In mathematics, the classical Plateau problem consists of finding the surface of least area that spans a given rigid boundary curve. A physical realization of the problem is obtained by dipping a stiff wire frame of some given shape in soapy water and ... More
Solution of a Yang-Baxter systemNov 04 1998Nov 05 1998Yang-Baxter system related to quantum doubles is introduced and large class of both continuous and discrete symmetries of the solution manifold are determined. Strategy for solution of the system based on the symmetries is suggested and accomplished in ... More
Does the complex Langevin method give unbiased results?Nov 19 2016We investigate whether the stationary solution of the Fokker-Planck equation of the complex Langevin algorithm reproduces the correct expectation values. When the complex Langevin algorithm for an action $S(x)$ is convergent, it produces an equivalent ... More
Comment on "Quantum back-reaction through the Bohmian particle"Feb 17 2003In this Comment I point out some limitations of the proposal of Prezhdo and Brooksby for coupling quantum and classical degrees of freedom (Phys.Rev.Lett.86(2001)3215) if it is pushed too far.
Generalized heat kernel coefficientsJul 16 2001Sep 26 2001Following Osipov and Hiller, a generalized heat kernel expansion is considered for the effective action of bosonic operators. In this generalization, the standard heat kernel expansion, which counts inverse powers of a c-number mass parameter, is extended ... More
Comment on ``A quantum-classical bracket that satisfies the Jacobi identity'' [J. Chem. Phys. 124, 201104 (2006)]Jan 10 2007It shown that the quantum-classical dynamical bracket recently proposed in J. Chem. Phys. 124, 201104 (2006) fails to satisfy the Jacobi identity.
Minimum uncertainty for antisymmetric wave functionsJun 05 1997We study how the entropic uncertainty relation for position and momentum conjugate variables is minimized in the subspace of one-dimensional antisymmetric wave functions. Based partially on numerical evidence and partially on analytical results, a conjecture ... More
Optical Doppler shift measurement using a rotating mirrorJul 24 2006Sep 22 2006Optical Doppler shift demonstration experiments are not a simple task since the light source cannot usually be moved in a sufficiently smooth and uniform manner to keep the level of noise well below of that of the signal. For that reason most demonstration ... More
Positive representations of complex distributions on groupsMay 04 2018Oct 29 2018A normalizable complex distribution $P(x)$ on a manifold $\mathcal{M}$ can be regarded as a complex weight, thereby allowing to define expectation values of observables $A(x)$ defined on $\mathcal{M}$. Straightforward importance sampling, $x\sim P$, is ... More
Stability of a Time-varying Fishing Model with DelayJan 19 2006We introduce a delay nonlinear differential equation model which describes how fish are harvested. In our previous studies we investigated the persistence of that equation and existence of a periodic solution for this equation. Here we study the stability ... More
Relativistic and thermal effects on the magnon spectrum of a ferromagnetic monolayerAug 09 2013Nov 29 2013A spin model including magnetic anisotropy terms and Dzyaloshinsky-Moriya interactions is studied for the case of a ferromagnetic monolayer with C2v symmetry like Fe/W(110). Using the quasiclassical stochastic Landau-Lifshitz-Gilbert equations, the magnon ... More
What Future Expects Humanity After the Demographic Transition Time?Oct 07 2000The variant of phenomenological theory of humankind future existence after time of demographic transition based on treating the time of demographic transition as a point of phase transition and taking into account an appearing of the new phase of mankind ... More
Nonlinear electron and spin transport in semiconductor superlatticesJul 24 2008Nonlinear charge transport in strongly coupled semiconductor superlattices is described by Wigner-Poisson kinetic equations involving one or two minibands. Electron-electron collisions are treated within the Hartree approximation whereas other inelastic ... More
Fractal Power Law in Literary EnglishJan 15 2005Jun 03 2005We present in this paper a numerical investigation of literary texts by various well-known English writers, covering the first half of the twentieth century, based upon the results obtained through corpus analysis of the texts. A fractal power law is ... More
Ion-Chain Dynamics in Polymer ElectrolytesApr 23 1996Representing polyether-salt systems by chains of interacting coordination shells, defined by the cation and by its nearest ligands, we derive the interaction potential between closest shells -- the inter-shells potential -- in terms of two-electron polarization ... More
A one-sided knot ejection at the core of the HH 111 outflowDec 07 2012We present an astrometry study of the radio source VLA 1 at the core of the HH 111 outflow using new data (2007) as well as archival observations (1992-1996). All data were taken at 3.6 cm with the Very Large Array in its most extended (A) configuration. ... More
Anisotropy of the superconducting fluctuations in multiband superconductors: the case of LiFeAsJul 08 2014Nov 14 2014Between the different families of pnictide multiband superconductors, LiFeAs is probably one of the less understood. Indeed, despite the large amount of experiments performed in the last few years on this material, no consensus has been reached yet on ... More
Gedanken Experiments involving Black HolesAug 20 1993Analysis of several gedanken experiments indicates that black hole complementarity cannot be ruled out on the basis of known physical principles. Experiments designed by outside observers to disprove the existence of a quantum-mechanical stretched horizon ... More
On the measure of Lagrangian invariant tori in nearly--integrable mechanical systems (draft)Mar 27 2015Consider a real--analytic nearly--integrable mechanical system with potential $f$, namely, a Hamiltonian system, having a real-analytic Hamiltonian $$ H(y,x)=\frac12 | y |^2 +\e f(x)\ , $$ $y,x$ being $n$--dimensional standard action--angle variables ... More
On the Evaluation and Comparison of Taggers: The Effect of Noise in Testing CorporaSep 28 1998This paper addresses the issue of {\sc pos} tagger evaluation. Such evaluation is usually performed by comparing the tagger output with a reference test corpus, which is assumed to be error-free. Currently used corpora contain noise which causes the obtained ... More
Poisson-Lie T-plurality of three-dimensional conformally invariant sigma models II: Nondiagonal metrics and dilaton puzzleAug 17 2004Sep 29 2005We look for 3-dimensional Poisson-Lie dualizable sigma models that satisfy the vanishing beta-function equations with constant dilaton field. Using the Poisson-Lie T-plurality we then construct 3-dimensional sigma models that correspond to various decompositions ... More
Classification of 6-dimensional real Manin triplesFeb 21 2002Mar 27 2002We present a complete list of 6-dimensional Manin triples or, equivalently, of 3-dimensional Lie bialgebras. We start from the well known classification of 3-dimensional real Lie algebras and assume the canonical bilinear form on the 6-dimensional Drinfeld ... More