Results for "S. Giaccari"

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Weyl transformations and trace anomalies in N=1, D=4 supergravitiesMay 30 2013Jul 07 2013We identify the supersymmetric extension of Weyl transformations in various types of supergravities, the minimal, nonminimal and new minimal N=1 SUGRA in 4D, formulated in terms of superfields. Based also on previous results we conclude that there are ... More
Analytic solutions for Dp branes in SFTJun 20 2011This is the follow-up of a previous paper [ArXiv:1105.5926], where we calculated the energy of an analytic lump solution in SFT, representing a D24-brane. Here we describe an analytic solution for a Dp-brane, for any p, and compute its energy.
Lump solutions in SFT. ComplementsSep 20 2011May 18 2012Recently a possible violation of the equation of motion for the recently proposed lump solutions in open SFT has been pointed out in the literature. In this paper we argue that, when the issue is considered in the appropriate mathematical setting of distribution ... More
The energy of the analytic lump solution in SFTMay 30 2011Aug 01 2013In a previous paper a method was proposed to find exact analytic solutions of open string field theory describing lower dimensional lumps, by incorporating in string field theory an exact renormalization group flow generated by a relevant operator in ... More
Worldline quantization of field theory, effective actions and $L_\infty$ structureFeb 08 2018We formulate the worldline quantization of a massive fermion model coupled to external higher spin sources. We use the relations obtained in this way to show that its regularized effective action is endowed with an $L_\infty$ symmetry. The same result ... More
HS in flat spacetime. YM-like modelsDec 12 2018Dec 16 2018We introduce and analyze a few examples of massless higher spin theories in Minkowski spacetime. They are defined in terms of master fields, i.e. fields defined in the whole phase space. More specifically we introduce the HS YM-like theories in any dimension ... More
HS in flat spacetime. The effective action methodNov 12 2018Mar 29 2019This is the first paper in a series of three dealing with HS theories in flat spacetime. It is divided in three parts. The first part is an elaboration on the method of effective action, initiated in a previous paper. We study the properties of correlators ... More
Causality in Nonlocal GravityMar 23 2018We study the causal structure of a class of weakly nonlocal gravitational theories (eventually coupled to matter) that are compatible with perturbative unitarity and finiteness at quantum level. In particular, we show that in nonlocal quantum gravity ... More
One-loop effective actions and higher spinsSep 07 2016Sep 15 2016The idea we advocate in this paper is that the one-loop effective action of a free (massive) field theory coupled to external sources (via conserved currents) contains complete information about the classical dynamics of such sources. We show many explicit ... More
Axial gravity: a non-perturbative approach to split anomaliesJul 03 2018Jul 04 2018In a theory of a Dirac fermion field coupled to a metric-axial-tensor (MAT) background, using a Schwinger-DeWitt heat kernel technique, we compute non-perturbatively the two (odd parity) trace anomalies. A suitable collapsing limit of this model corresponds ... More
One-loop effective actions and higher spins. IISep 06 2017In this paper we continue and improve the analysis of the effective actions obtained by integrating out a scalar and a fermion field coupled to external symmetric sources, started in the previous paper. The first subject we study is the geometrization ... More
One-loop effective actions and higher spinsSep 07 2016Nov 14 2016The idea we advocate in this paper is that the one-loop effective action of a free (massive) field theory coupled to external sources (via conserved currents) contains complete information about the classical dynamics of such sources. We show many explicit ... More
Worldline quantization of field theory, effective actions and $L_\infty$ structureFeb 08 2018May 11 2018We formulate the worldline quantization of a massive fermion model coupled to external higher spin sources. We use the relations obtained in this way to show that its regularized effective action is endowed with an $L_\infty$ symmetry. The same result ... More
Axial gravity, massless fermions and trace anomaliesMar 30 2017May 24 2017This article deals with two main topics. One is odd parity trace anomalies in Weyl fermion theories in a 4d curved background, the second is the introduction of axial gravity. The motivation for reconsidering the former is to clarify the theoretical background ... More
Consistent gravitational anomalies for chiral bosonsDec 15 2008Feb 12 2009Exact consistent gravitational anomalies for chiral bosons in two dimensions are treated both with the Schwinger-DeWitt regularization and independently through a cohomological procedure. The diffeomorphism transformations are described by a single ghost ... More
Generalized states in SFTApr 08 2013Oct 18 2013The search for analytic solutions in open string fields theory \`a la Witten often meets with singular expressions, which need an adequate mathematical formalism to be interpreted. In this paper we discuss this problem and propose a way to resolve the ... More
Dark Solitons, D-branes and Noncommutative Tachyon Field TheoryAug 25 2016In this paper we discuss the boson/vortex duality by mapping the Gross-Pitaevskii theory into an effective string theory, both with and without boundaries. Through the effective string theory, we find the Seiberg-Witten map between the commutative and ... More
Classical and Quantum Nonlocal SupergravityMay 12 2016We derive the N=1 supersymmetric extension for a class of weakly nonlocal four dimensional gravitational theories.The construction is explicitly done in the superspace and the tree-level perturbative unitarity is explicitly proved both in the superfield ... More
Trace anomalies in chiral theories revisitedMar 11 2014Aug 29 2014Motivated by the search for possible CP violating terms in the trace of the energy-momentum tensor in theories coupled to gravity we revisit the problem of trace anomalies in chiral theories. We recalculate the latter and ascertain that in the trace of ... More
Scattering amplitudes in super-renormalizable gravityJun 15 2015We explicitly compute the tree-level on-shell four-graviton amplitudes in four, five and six dimensions for local and weakly nonlocal gravitational theories that are quadratic in both, the Ricci and scalar curvature with form factors of the d'Alembertian ... More
Finite Entanglement Entropy of Black HolesDec 19 2015We compute the area term contribution to the black holes' entanglement entropy for a class of local or weakly nonlocal renormalizable gravitational theories coupled to matter. For the case of super-renormalizable theories, we can get a finite conical ... More
Multi-Objective Genetic Algorithm Optimisation for an Array of Cherenkov TelescopesAug 28 2017We have conceived and implemented a multi-objective genetic algorithm (GA) code for the optimisation of an array of Imaging Atmospheric Cherenkov Telescopes (IACTs). The algorithm takes as input a series of cost functions (metrics) each describing a different ... More
Search for a correlation between the UHECRs measured by the Pierre AugerObservatory and the Telescope Array and the neutrino candidate events fromIceCube and ANTARESMay 10 2019High-energy neutrinos are expected to be produced by the interaction of accelerated particles near the acceleration sites. For this reason, it is interesting to search for correlation in the arrival directions of ultra-high energy cosmic rays (UHECRs) ... More
Finite Entanglement Entropy of Black HolesDec 19 2015Jun 16 2018We compute the area term contribution to black holes' entanglement entropy (using the conical technique) for a class of local or weakly non-local super-renormalizable gravitational theories coupled to matter. For the first time, we explicitly prove that ... More
MARTA: A high-energy cosmic-ray detector concept with high-accuracy muon measurementDec 20 2017Apr 20 2018A new concept for the direct measurement of muons in air showers is presented. The concept is based on resistive plate chambers (RPCs), which can directly measure muons with very good space and time resolution. The muon detector is shielded by placing ... More
MARTA: A high-energy cosmic-ray detector concept with high-accuracy muon measurementDec 20 2017A new concept for the direct measurement of muons in air showers is presented. The concept is based on resistive plate chambers (RPCs), which can directly measure muons with very good space and time resolution. The muon detector is shielded by placing ... More
Indication of anisotropy in arrival directions of ultra-high-energy cosmic rays through comparison to the flux pattern of extragalactic gamma-ray sourcesJan 18 2018Feb 06 2018A new analysis of the dataset from the Pierre Auger Observatory provides evidence for anisotropy in the arrival directions of ultra-high-energy cosmic rays on an intermediate angular scale, which is indicative of excess arrivals from strong, nearby sources. ... More
Search for anisotropies in cosmic-ray positrons detected by the PAMELA experimentSep 21 2015Oct 08 2015The PAMELA detector was launched on board of the Russian Resurs-DK1 satellite on June 15, 2006. Data collected during the first four years have been used to search for large-scale anisotropies in the arrival directions of cosmic-ray positrons. The PAMELA ... More
Muon Counting using Silicon Photomultipliers in the AMIGA detector of the Pierre Auger ObservatoryMar 17 2017Oct 04 2017AMIGA (Auger Muons and Infill for the Ground Array) is an upgrade of the Pierre Auger Observatory designed to extend its energy range of detection and to directly measure the muon content of the cosmic ray primary particle showers. The array will be formed ... More
Spectral Calibration of the Fluorescence Telescopes of the Pierre Auger ObservatorySep 05 2017Oct 02 2017We present a novel method to measure precisely the relative spectral response of the fluorescence telescopes of the Pierre Auger Observatory. We used a portable light source based on a xenon flasher and a monochromator to measure the relative spectral ... More
A targeted search for point sources of EeV photons with the Pierre Auger ObservatoryDec 13 2016Mar 21 2017Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to ... More
Evidence for a mixed mass composition at the `ankle' in the cosmic-ray spectrumSep 27 2016Nov 22 2016We report a first measurement for ultra-high energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the surface detectors ... More
Ultrahigh-energy neutrino follow-up of Gravitational Wave events GW150914 and GW151226 with the Pierre Auger ObservatoryAug 26 2016Jan 13 2017On September 14, 2015 the Advanced LIGO detectors observed their first gravitational-wave (GW) transient GW150914. This was followed by a second GW event observed on December 26, 2015. Both events were inferred to have arisen from the merger of black ... More
Observation of a Large-scale Anisotropy in the Arrival Directions of Cosmic Rays above $8 \times 10^{18}$ eVSep 21 2017Cosmic rays are atomic nuclei arriving from outer space that reach the highest energies observed in nature. Clues to their origin come from studying the distribution of their arrival directions. Using $3 \times 10^4$ cosmic rays above $8 \times 10^{18}$ ... More
Calibration of the Logarithmic-Periodic Dipole Antenna (LPDA) Radio Stations at the Pierre Auger Observatory using an OctocopterFeb 05 2017Jun 13 2018An in-situ calibration of a logarithmic periodic dipole antenna with a frequency coverage of 30 MHz to 80 MHz is performed. Such antennas are part of a radio station system used for detection of cosmic ray induced air showers at the Engineering Radio ... More
Search for photons with energies above 10$^{18}$ eV using the hybrid detector of the Pierre Auger ObservatoryDec 05 2016Apr 07 2017A search for ultra-high energy photons with energies above 1 EeV is performed using nine years of data collected by the Pierre Auger Observatory in hybrid operation mode. An unprecedented separation power between photon and hadron primaries is achieved ... More
Multi-Messenger Physics with the Pierre Auger ObservatoryApr 26 2019An overview of the multi-messenger capabilities of the Pierre Auger Observatory is presented. The techniques and performance of searching for Ultra-High Energy neutrinos, photons and neutrons are described. Some of the most relevant results are reviewed, ... More
Inferences on Mass Composition and Tests of Hadronic Interactions from 0.3 to 100 EeV using the water-Cherenkov Detectors of the Pierre Auger ObservatoryOct 19 2017We present a new method for probing the hadronic interaction models at ultra-high energy and extracting details about mass composition. This is done using the time profiles of the signals recorded with the water-Cherenkov detectors of the Pierre Auger ... More
Combined fit of spectrum and composition data as measured by the Pierre Auger ObservatoryDec 21 2016Feb 26 2018We present a combined fit of a simple astrophysical model of UHECR sources to both the energy spectrum and mass composition data measured by the Pierre Auger Observatory. The fit has been performed for energies above $5 \cdot 10^{18}$ eV, i.e.~the region ... More
Pierre Auger Observatory and Telescope Array: Joint Contributions to the 34th International Cosmic Ray Conference (ICRC 2015)Nov 06 2015Joint contributions of the Pierre Auger Collaboration and the Telescope Array Collaboration to the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands.
Reconstruction of inclined air showers detected with the Pierre Auger ObservatoryJul 11 2014We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than $60^\circ$ detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density ... More
Testing Hadronic Interactions at Ultrahigh Energies with Air Showers Measured by the Pierre Auger ObservatoryOct 26 2016Oct 31 2016Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events ... More
A Targeted Search for Point Sources of EeV NeutronsJun 16 2014A flux of neutrons from an astrophysical source in the Galaxy can be detected in the Pierre Auger Observatory as an excess of cosmic-ray air showers arriving from the direction of the source. To avoid the statistical penalty for making many trials, classes ... More
The Fluorescence Detector of the Pierre Auger ObservatoryJul 24 2009The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere ... More
Operations of and Future Plans for the Pierre Auger ObservatoryJun 12 2009Jul 10 2009Technical reports on operations and features of the Pierre Auger Observatory, including ongoing and planned enhancements and the status of the future northern hemisphere portion of the Observatory. Contributions to the 31st International Cosmic Ray Conference, ... More
Prototype muon detectors for the AMIGA component of the Pierre Auger ObservatoryMay 05 2016May 12 2016Auger Muons and Infill for the Ground Array) is an upgrade of the Pierre Auger Observatory to extend its range of detection and to directly measure the muon content of the particle showers. It consists of an infill of surface water-Cherenkov detectors ... More
Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showersDec 07 2015Feb 15 2016To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on ... More
The Pierre Auger Observatory Upgrade - Preliminary Design ReportApr 13 2016The Pierre Auger Observatory has begun a major Upgrade of its already impressive capabilities, with an emphasis on improved mass composition determination using the surface detectors of the Observatory. Known as AugerPrime, the upgrade will include new ... More
Searches for Large-Scale Anisotropy in the Arrival Directions of Cosmic Rays Detected above Energy of $10^{19}$ eV at the Pierre Auger Observatory and the Telescope ArraySep 10 2014Spherical harmonic moments are well-suited for capturing anisotropy at any scale in the flux of cosmic rays. An unambiguous measurement of the full set of spherical harmonic coefficients requires full-sky coverage. This can be achieved by combining data ... More
Band insulator to Mott insulator transition in a bilayer Hubbard modelMar 27 2007The ground state phase diagram of the half-filled repulsive Hubbard model in a bilayer is investigated using cluster dynamical mean field theory. For weak to intermediate values of Coulomb repulsion $U$, the system undergoes a transition from a Mott insulating ... More
NNLO classical solution for Lipatov's effective action for reggeized gluonsFeb 15 2018Mar 19 2018We consider the formalism of small-x effective action for reggeized gluons, Gribov (Sov Phys JETP 26:414, 1968), Lipatov (Nucl Phys B 452:369, 1995; Phys Rep 286:131, 1997; Subnucl Ser 49:131, 2013, Int J Mod Phys Conf Ser 39:1560082, 2015; Int J Mod ... More
Event-Driven Molecular Dynamics in ParallelFeb 03 2003Sep 16 2003Although event-driven algorithms have been shown to be far more efficient than time-driven methods such as conventional molecular dynamics, they have not become as popular. The main obstacle seems to be the difficulty of parallelizing event-driven molecular ... More
Band dispersion and electronic lifetimes in crystalline organic semiconductorsJan 11 2011Mar 31 2011The consequences of several microscopic interactions on the photoemission spectra of crystalline organic semiconductors (OSC) are studied theoretically. It is argued that their relative roles can be disentangled by analyzing both their temperature and ... More
Band-like motion and mobility saturation in organic molecular semiconductorsOct 22 2009Dec 07 2009We analyze a model that accounts for the inherently large thermal lattice fluctuations associated to the weak van der Waals inter-molecular bonding in crystalline organic semiconductors. In these materials the charge mobility generally exhibits a "metallic-like" ... More
Optical properties of small polarons from dynamical mean-field theoryDec 09 2005Feb 27 2006The optical properties of polarons are studied in the framework of the Holstein model by applying the dynamical mean-field theory. This approach allows to enlighten important quantitative and qualitative deviations from the limiting treatments of small ... More
Hopping dynamics of interacting polaronsOct 02 2008We derive an effective cluster model to address the transport properties of mutually interacting small polarons. We propose a decoupling scheme where the hopping dynamics of any given particle is determined by separating out explicitly the degrees of ... More
Metric-affine $f(R)$-gravity with torsion: an overviewOct 27 2009Torsion and curvature could play a fundamental role in explaining cosmological dynamics. f(R)-gravity with torsion is an approach aimed to encompass in a comprehensive scheme all the Dark Side of the Universe (Dark Energy and Dark Matter). We discuss ... More
Groups of quasi-invariance and the Pontryagin dualityDec 09 2008Oct 01 2009A Polish group $G$ is called a group of quasi-invariance or a QI-group, if there exist a locally compact group $X$ and a probability measure $\mu$ on $X$ such that 1) there exists a continuous monomorphism of $G$ to $X$, and 2) for each $g\in X$ either ... More
The Higgs Boson Production Cross Section as a Precision Observable?Mar 06 2002Jul 30 2002We investigate what can be learned at a linear collider about the sector of electroweak symmetry breaking from a precise measurement of the Higgs boson production cross section through the process e+e- -> hZ. We focus on deviations from the Standard Model ... More
X-ray observations of cluster outskirts: current status and future prospectsMay 03 2010Dec 22 2010Past and current X-ray mission allow us to observe only a fraction of the volume occupied by the ICM. After reviewing the state of the art of cluster outskirts observations we discuss some important constraints that should be met when designing an experiment ... More
Lower and upper bounds on the mass of light quark-antiquark scalar resonance in the SVZ sum rulesMay 23 2016The calculation of the mass of light scalar isosinglet meson within the Shifman--Vainshtein--Zakharov (SVZ) sum rules is revisited. We develop simple analytical methods for estimation of hadron masses in the SVZ approach and try to reveal the origin of ... More
Low-energy holographic models for QCDFeb 01 2011Apr 09 2011We consider the bottom-up holographic models for QCD which contain the ultraviolet (UV) cutoff. Such models are supposed to describe exclusively the low-energy sector of QCD. The introduction of UV cutoff in the soft wall model is shown to result in a ... More
AdS/QCD models describing a finite number of excited mesons with Regge spectrumMar 02 2009The typical AdS/QCD models deal with the large-N_c limit of QCD, as a consequence the meson spectrum consists of the infinite number of states that is far from the real situation. Basing on introduction of anharmonic corrections to the holographic potential, ... More
Generalized Soft Wall ModelOct 18 2012Jan 27 2013We develop an exactly solvable generalization of the soft wall holographic model for the vector mesons. The generalization preserves the ultraviolet and infrared asymptotics of the soft wall model and contains an additional free parameter. This new parameter ... More
Comment on "Parity Doubling and SU(2)_L X SU(2)_R Restoration in the Hadronic Spectrum" and "Parity Doubling Among the Baryons"May 09 2006Some aspects of two recent papers on parity doubling in the hadronic spectrum and its relation to restoration of linearly realized chiral symmetry are critically discussed.
Steenrod operations and the diagonal morphismJul 04 2013Jan 15 2014We show how to find the Steenrod operations in H^*(X) (the coefficients in F_p) given the diagonal morphism d_#:S_*(X)->S_*(X^p) and the action of the cyclic group C_p on S_*(X^p). Our construction needs no other data such as Eilenberg-Zilber morphisms. ... More
The Game of Cipher BeadsMay 20 2009Jul 29 2009Comparison between the various impact factors of a few Russian journals demonstrates the deficiencies of the popular citation indices.
On Grothendieck SubspacesApr 04 2005The modulus of an order bounded functional on a Riesz space is the sum of a pair of Riesz homomorphisms if and only if the kernel of this functional is a Grothendieck subspace of the ambient Riesz space. An operator version of this fact is given.
Generalized Integral Siding Mode Manifold Design: A Sum of Squares ApproachMar 30 2015May 21 2015This paper presents a general form of integral sliding mode manifold, and proposes an algorithmic approach based on Sum of Squares (SOS) programming to design generalized integral sliding mode manifold and controller for nonlinear systems with both matched ... More
Effective Use of Human Computer Interaction in Digital Academic Supportive DevicesJan 03 2015In this research, a literature in human-computer interaction is reviewed and the technology aspect of human computer interaction related with digital academic supportive devices is also analyzed. According to all these concerns, recommendations to design ... More
Influence of Facebook in Academic Performance of Sri Lankan University StudentsJan 03 2015Facebook is only an electronic communication between human but unfortunately it has become an addiction for all. This paper examines the usage of Facebook among university students and its influence in their academic performance. The impact of Facebook ... More
Di-photon Higgs signals at the LHC in the Next-to-Minimal Supersymmetric Standard ModelMar 10 2006The NMSSM contains a Higgs singlet in addition to the two Higgs doublets typical of the MSSM, thus resulting in a total of seven physical Higgs mass states. Therefore, the phenomenology of the NMSSM Higgs sector can vary considerably from that of the ... More
Shock Dissipation in Magnetically Dominated Impulsive FlowsJan 17 2012We have revisited the issue of shock dissipation and emission and its implications for the internal shock model of the prompt GRB emission and studied it in the context of impulsive Poynting-dominated flows. Our results show that unless the magnetization ... More
3+1 MagnetodynamicsAug 17 2011Aug 30 2011The Magnetodynamics, or Force-Free Degenerate Electrodynamics, is recognized as a very useful approximation in studies of magnetospheres of relativistic stars. In this paper we discuss various forms of Magnetodynamic equations which can be used to study ... More
Blandford-Znajek mechanism versus Penrose processApr 11 2008During the three decades since its theoretical discovery the Blandford-Znajek process of extracting the rotational energy of black holes has become one of the foundation stones in the building of modern relativistic astrophysics. However, it is also true ... More
Multi-dimensional Numerical Scheme for Resistive Relativistic MHDAug 02 2007The paper describes a new upwind conservative numerical scheme for special relativistic resistive magnetohydrodynamics with scalar resistivity. The magnetic field is kept approximately divergence free and the divergence of the electric field consistent ... More
The eta-photon transition form factorOct 28 2011Feb 08 2012The eta-photon transition form factor is evaluated in a formalism based on a phenomenological description at low values of the photon virtuality, and a QCD-based description at high photon virtualities, matching at a scale $Q_{0}^{2}$. The high photon ... More
Geometry of N=4, d=1 nonlinear supermultipletNov 09 2006We construct the general action for $N=4, d=1$ nonlinear supermultiplet including the most general interaction terms which depend on the arbitrary function $h$ obeying the Laplace equation on $S^3$. We find the bosonic field $B$ which depends on the components ... More
Random walks in a random environmentMar 05 2005Random walks as well as diffusions in random media are considered. Methods are developed that allow one to establish large deviation results for both the `quenched' and the `averaged' case.
Heavy charged Higgs boson production at next generation $γγ$ collidersNov 05 2002We investigate the scope of all relevant production modes of charged Higgs bosons in the MSSM, with mass larger than the one of the top quark, at future Linear Colliders operating in $\gamma\gamma$ mode at the TeV energy scale. Final states with one or ... More
Electron-hole asymmetry in magnetic properties of lightly doped high-$T_{\rm C}$ superconductors: a quantum Monte Carlo studyAug 14 2003Using a recently developed variational quantum Monte Carlo method, magnetic properties of high-$T_{\rm C}$ superconductors are studied at zero temperature ($T$), by numerical simulations on the 2D t-J model. Our focus here is to explore the difference ... More
Review and Analysis of The Issues of Unified Modeling Language for Visualizing, Specifying, Constructing and Documenting the Artifacts of a Software-Intensive SystemJan 23 2010The UML allows us to specify models in a precise, complete and unambiguous manner. In particular, the UML addresses the specification of all important decisions regarding analysis, design and implementation. Although UML is not a visual programming language, ... More
Reducing Polarization Mode Dispersion With Controlled Polarization RotationsJun 02 2006One of the fundamental limitations to high bit rate, long distance, telecommunication in optical fibers is Polarization Mode Dispersion (PMD). Here we introduce a conceptually new method to reduce PMD in optical fibers by carrying out controlled rotations ... More
Superconducting networks with the proximity effectNov 06 2009May 20 2011We report on the first observation of a novel type of superconducting proximity network using a superconductor-normal metal bilayer. Little-Parks oscillation measurements show that the superconducting current flows through a path enclosed by the edge ... More
An Observational Perspective of the IMF: Progress and ChallengesOct 20 2015The stellar initial mass function (IMF) is a fundamental astrophysical quantity that impacts a wide range of astrophysical problems from heavy element distribution to galactic evolution to planetary system formation. However, the origin and universality ... More
The mass function of young star clusters in spiral galaxiesDec 07 2008Sep 23 2009The initial cluster mass function (ICMF) in spiral galaxy discs is constrained and compared with data for old globular clusters and young clusters in starbursts. It is found that the observed ages and luminosities of the brightest clusters in spiral discs ... More
Observational Constraints on Cluster EvolutionSep 04 2006Current observational constraints on the dynamical evolution of star clusters are reviewed. Theory and observations now agree nicely on the mass dependency and time scales for disruption of young star clusters in galactic disks, but many problems still ... More
Zero-Range Potentials in Multi-Channel Diatomic Molecule ScatteringMay 17 2002The method of zero-range potentials is generalized to account for the molecular electron excitation process. It is made by a matrix formulation in which a state vector components are associated with a scattering channel. The multi-center target is considered ... More
On the possibility of Casimir repulsion using MetamaterialsSep 15 2009It is well known that the Casimir force between two half-spaces is dictated by their electromagnetic properties. In particular, when one of the half-spaces is mainly metallic or dielectric and the other is mainly magnetic, it is possible to show that ... More
Finite-size effects on the Hamiltonian dynamics of the XY-modelMay 31 2001The dynamical properties of the finite-size magnetization M in the critical region T<T_{KTB} of the planar rotor model on a L x L square lattice are analyzed by means of microcanonical simulations . The behavior of the q=0 structure factor at high frequencies ... More
Light-front $φ^4_{1+1}$ theory using a many-boson symmetric-polynomial basisDec 29 2015We extend earlier work on fully symmetric polynomials for three-boson wave functions to arbitrarily many bosons and apply these to a light-front analysis of the low-mass eigenstates of $\phi^4$ theory in 1+1 dimensions. The basis-function approach allows ... More
Application of a light-front coupled-cluster method to quantum electrodynamicsJun 26 2012A field-theoretic formulation of the exponential-operator technique is applied to a Hamiltonian eigenvalue problem in electrodynamics, quantized in light-front coordinates. Specifically, we consider the dressed-electron state, without positron contributions ... More
Magnetization induced by odd-frequency spin-triplet Cooper pairs in a Josephson junction with metallic trilayersJul 14 2015We theoretically study the magnetization inside a normal metal induced in an s-wave superconductor/ferromagnetic metal/normal metal/ferromagnetic metal/s-wave superconductor (S/F1/N/F2/S) Josephson junction. Using quasiclassical Green's function method, ... More
Relativistic Toda chain at root of unityJan 15 2001May 17 2001We declare briefly several interesting features of the quantum relativistic Toda chain at N-th root of unity. We consider the finite dimensional representation of the Weyl algebra. The origin of the features mentioned is that we consider simultaneously ... More
Spin Injection and Detection in Magnetic NanostructuresDec 13 2002We study theoretically the spin transport in a nonmagnetic metal connected to ferromagnetic injector and detector electrodes. We derive a general expression for the spin accumulation signal which covers from the metallic to the tunneling regime. This ... More
Threshold Based Indexing of Commercial Shoe Print to Create Reference and Recovery ImagesJan 29 2010One of the important evidence in a crime scene that is normally overlooked but very important evidence is shoe print as the criminal is normally unaware of the mask for this. In this paper we use image processing technique to process reference shoe images ... More
From transient localization to band transport: on quantum corrections and lack thereofMar 29 2019Transient localization has emerged as a powerful theoretical framework that is able to describe charge transport in high-mobility organic semiconductors, where the carrier diffusion is strongly limited by their coupling to thermal molecular motions. As ... More
Effect of Diorder on the Peak Effect and Structure of Flux Line Lattice in 2H-NbSe2Sep 16 1997The effect of disorder on flux line lattice (FLL) melting is studied via the Peak Effect phenomenon. On the upper branch of the Peak Effect curve, where this effect is more robust, we observe a stepwise disordering of the FLL, suggesting two first order ... More