Results for "A. Corstanje"

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LOFAR: Detecting Cosmic Rays with a Radio TelescopeSep 27 2011LOFAR (the Low Frequency Array), a distributed digital radio telescope with stations in the Netherlands, Germany, France, Sweden, and the United Kingdom, is designed to enable full-sky monitoring of transient radio sources. These capabilities are ideal ... More
An air shower array for LOFAR: LORAFeb 04 2011LOFAR is a new form of radio telescope which can detect radio emission from air showers induced by very high-energy cosmic rays. It can also look for radio emission from particle cascades on the Moon induced by ultra high-energy cosmic rays or neutrinos. ... More
Calibration of the LOFAR low-band antennas using the Galaxy and a model of the signal chainMar 14 2019The LOw-Frequency ARray (LOFAR) is used to make precise measurements of radio emission from extensive air showers, yielding information about the primary cosmic ray. Interpreting the measured data requires an absolute and frequency-dependent calibration ... More
Search for Cosmic Particles with the Moon and LOFARSep 21 2016The low flux of the ultra-high energy cosmic rays (UHECR) at the highest energies provides a challenge to answer the long standing question about their origin and nature. A significant increase in the number of detected UHECR is expected to be achieved ... More
A method for high precision reconstruction of air shower Xmax using two-dimensional radio intensity profilesAug 29 2014Sep 01 2014The mass composition of cosmic rays contains important clues about their origin. Accurate measurements are needed to resolve long-standing issues such as the transition from Galactic to extragalactic origin, and the nature of the cutoff observed at the ... More
Timing calibration and spectral cleaning of LOFAR time series dataMar 28 2016We describe a method for spectral cleaning and timing calibration of short voltage time series data from individual radio interferometer receivers. It makes use of the phase differences in Fast Fourier Transform (FFT) spectra across antenna pairs. For ... More
The radio emission pattern of air showers as measured with LOFAR - a tool for the reconstruction of the energy and the shower maximumNov 28 2014Apr 13 2015The pattern of the radio emission of air showers is finely sampled with the Low-Frequency ARray (LOFAR). A set of 382 measured air showers is used to test a fast, analytic parameterization of the distribution of pulse powers. Using this parameterization ... More
LORA: A scintillator array for LOFAR to measure extensive air showersAug 19 2014The measurement of the radio emission from extensive air showers, induced by high-energy cosmic rays is one of the key science projects of the LOFAR radio telescope. The LOfar Radboud air shower Array (LORA) has been installed in the core of LOFAR in ... More
Polarized radio emission from extensive air showers measured with LOFARJun 05 2014Sep 09 2014We present LOFAR measurements of radio emission from extensive air showers. We find that this emission is strongly polarized, with a median degree of polarization of nearly $99\%$, and that the angle between the polarization direction of the electric ... More
Measurement of the cosmic-ray energy spectrum above $10^{16}$ eV with the LOFAR Radboud Air Shower ArrayJun 30 2015Jul 01 2015The energy reconstruction of extensive air showers measured with the LOFAR Radboud Air Shower Array (LORA) is presented in detail. LORA is a particle detector array located in the center of the LOFAR radio telescope in the Netherlands. The aim of this ... More
LOFAR discovery of a quiet emission mode in PSR B0823+26May 12 2015PSR B0823+26, a 0.53-s radio pulsar, displays a host of emission phenomena over timescales of seconds to (at least) hours, including nulling, subpulse drifting, and mode-changing. Studying pulsars like PSR B0823+26 provides further insight into the relationship ... More
Lunar occultation of the diffuse radio sky: LOFAR measurements between 35 and 80 MHzJul 16 2014We present radio observations of the Moon between $35$ and $80$ MHz to demonstrate a novel technique of interferometrically measuring large-scale diffuse emission extending far beyond the primary beam (global signal) for the first time. In particular, ... More
The shape of the radio wavefront of extensive air showers as measured with LOFARApr 15 2014Jun 08 2014Extensive air showers, induced by high energy cosmic rays impinging on the Earth's atmosphere, produce radio emission that is measured with the LOFAR radio telescope. As the emission comes from a finite distance of a few kilometers, the incident wavefront ... More
Measurement of the circular polarization in radio emission from extensive air showers confirms emission mechanismsNov 02 2016Nov 19 2016We report here on a novel analysis of the complete set of four Stokes parameters that uniquely determine the linear and/or circular polarization of the radio signal for an extensive air shower. The observed dependency of the circular polarization on azimuth ... More
Measurement of the circular polarization in radio emission from extensive air showers confirms emission mechanismsNov 02 2016We report here on a novel analysis of the complete set of four Stokes parameters that uniquely determine the linear and/or circular polarization of the radio signal for an extensive air shower. The observed dependency of the circular polarization on azimuth ... More
Influence of Atmospheric Electric Fields on the Radio Emission from Extensive Air ShowersNov 10 2015The atmospheric electric fields in thunderclouds have been shown to significantly modify the intensity and polarization patterns of the radio footprint of cosmic-ray-induced extensive air showers. Simulations indicated a very non-linear dependence of ... More
Measuring a Cherenkov ring in the radio emission from air showers at 110-190 MHz with LOFARNov 25 2014Measuring radio emission from air showers offers a novel way to determine properties of the primary cosmic rays such as their mass and energy. Theory predicts that relativistic time compression effects lead to a ring of amplified emission which starts ... More
Detecting Radio Emission from Air Showers with LOFARApr 03 2013LOFAR (the Low Frequency Array) is the largest radio telescope in the world for observing low frequency radio emission from 10 to 240 MHz. In addition to its use as an interferometric array, LOFAR is now routinely used to detect cosmic ray induced air ... More
Detecting cosmic rays with the LOFAR radio telescopeNov 06 2013The low frequency array (LOFAR), is the first radio telescope designed with the capability to measure radio emission from cosmic-ray induced air showers in parallel with interferometric observations. In the first $\sim 2\,\mathrm{years}$ of observing, ... More
The LOFAR Pilot Surveys for Pulsars and Fast Radio TransientsAug 02 2014We have conducted two pilot surveys for radio pulsars and fast transients with the Low-Frequency Array (LOFAR) around 140 MHz and here report on the first low-frequency fast-radio burst limit and the discovery of two new pulsars. The first survey, the ... More
Calibrating the absolute amplitude scale for air showers measured at LOFARJul 31 2015Dec 28 2015Air showers induced by cosmic rays create nanosecond pulses detectable at radio frequencies. These pulses have been measured successfully in the past few years at the LOw Frequency ARray (LOFAR) and are used to study the properties of cosmic rays. For ... More
Probing Atmospheric Electric Fields in Thunderstorms through Radio Emission from Cosmic-Ray-Induced Air ShowersApr 22 2015We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the ... More
Searching for Neutrino Radio Flashes from the Moon with LOFARJan 22 2013Ultra-high-energy neutrinos and cosmic rays produce short radio flashes through the Askaryan effect when they impact on the Moon. Earthbound radio telescopes can search the Lunar surface for these signals. A new generation of low- frequency, digital radio ... More
LBCS: the LOFAR Long-Baseline Calibrator SurveyAug 06 2016Sep 09 2016(abridged). We outline LBCS (the LOFAR Long-Baseline Calibrator Survey), whose aim is to identify sources suitable for calibrating the highest-resolution observations made with the International LOFAR Telescope, which include baselines >1000 km. Suitable ... More
Imaging Jupiter's radiation belts down to 127 MHz with LOFARNov 30 2015Context. Observing Jupiter's synchrotron emission from the Earth remains today the sole method to scrutinize the distribution and dynamical behavior of the ultra energetic electrons magnetically trapped around the planet (because in-situ particle data ... More
LOFAR MSSS: Detection of a low-frequency radio transient in 400 hrs of monitoring of the North Celestial PoleNov 30 2015We present the results of a four-month campaign searching for low-frequency radio transients near the North Celestial Pole with the Low-Frequency Array (LOFAR), as part of the Multifrequency Snapshot Sky Survey (MSSS). The data were recorded between 2011 ... More
A large light-mass component of cosmic rays at 10^{17} - 10^{17.5} eV from radio observationsMar 04 2016May 01 2016Cosmic rays are the highest energy particles found in nature. Measurements of the mass composition of cosmic rays between 10^{17} eV and 10^{18} eV are essential to understand whether this energy range is dominated by Galactic or extragalactic sources. ... More
Discovery of Carbon Radio Recombination Lines in absorption towards Cygnus~AJan 13 2014We present the first detection of carbon radio recombination line absorption along the line of sight to Cygnus A. The observations were carried out with the LOw Frequency ARray in the 33 to 57 MHz range. These low frequency radio observations provide ... More
LOFAR: The LOw-Frequency ARrayMay 15 2013May 19 2013LOFAR, the LOw-Frequency ARray, is a new-generation radio interferometer constructed in the north of the Netherlands and across europe. Utilizing a novel phased-array design, LOFAR covers the largely unexplored low-frequency range from 10-240 MHz and ... More
A study of RXTE and BeppoSAX observations of Cyg X-3Jan 14 2004We present an analysis of Cyg X-3 data from RXTE/PCA,HEXTE and ASM, supplemented by a selected spectrum from BeppoSAX. We fit the PCA/HEXTE spectra from 1996-2000 by a model including hybrid Comptonization, reflection and absorption, and classify them ... More
Non-reciprocal quantum interactions and devices via autonomous feed-forwardOct 20 2016In a recent work [A. Metelmann and A. A. Clerk, Phys. Rev. X 5, 021025 (2015)], a general reservoir-engineering approach for generating non-reciprocal quantum interactions and devices was described. We show here how in many cases this general recipe can ... More
Deciphering the minimum of energy of some walking technicolor modelsMay 11 2010There are quasi-conformal theories, like the Minimal and Ultraminimal Technicolor models, which may break dynamically the gauge symmetry of the Standard Model and at the same time are compatible with electroweak precision data. The main characteristic ... More
Strength of the Trilinear Higgs Boson Coupling in Technicolor ModelsOct 14 2005Oct 20 2005We discuss the strength of the trilinear Higgs boson coupling in technicolor (or composite) models in a model independent way. The coupling is determined as a function of a very general ansatz for the technicolor self-energy, and turns out to be equal ... More
Scalar bosons in Minimal and Ultraminimal Technicolor: Masses, trilinear couplings and widthsDec 05 2009May 04 2010We compute masses, trilinear self-couplings and decay widths into weak bosons of the scalar composite bosons in the case of the Minimal and Ultraminimal technicolor models. The masses, computed via the Bethe-Salpeter equation, turn out to be light and ... More
Topological response in Weyl semimetals and the chiral anomalyJun 08 2012Sep 25 2012We demonstrate that topological transport phenomena, characteristic of Weyl semimetals, namely the semi-quantized anomalous Hall effect and the chiral magnetic effect (equilibrium magnetic-field-driven current), may be thought of as two distinct manifestations ... More
Top quark threshold production in $γγ$ collision in the next-to-leading orderOct 27 1998Apr 23 1999The total cross section of the top quark-antiquark pair production near threshold in $\gamma\gamma$ collision is computed analytically up to the next-to-leading order in perturbative and nonrelativistic expansion for general photon helicity. The approximation ... More
On a subtle point of sum rules calculations: toy modelMar 30 1995We consider a two-point correlator in massless $\phi^3$ model within the ladder approximation . The spectral density of the correlator is known explicitly and does not contain any resonances. Meanwhile making use of the standard sum rules technique with ... More
Renormalization of the Yang-Mills theory in the ambiguity-free gaugeFeb 12 2010Jul 27 2010The renormalization procedure for the Yang-Mills theory in the gauge free of the Gribov ambiguity is constructed. It is shown that all the ultraviolet infinities may be removed by renormalization of the parameters entering the classical Lagrangian and ... More
Programming Realization of Symbolic Computations for Non-linear Commutator Superalgebras over the Heisenberg--Weyl Superalgebra: Data Structures and Processing MethodsMay 16 2009Aug 19 2009We suggest a programming realization of an algorithm for verifying a given set of algebraic relations in the form of a supercommutator multiplication table for the Verma module, which is constructed according to a generalized Cartan procedure for a quadratic ... More
Nonreciprocal Photon Transmission and Amplification via Reservoir EngineeringFeb 25 2015Jun 05 2015We discuss a general method for constructing nonreciprocal, cavity-based photonic devices, based on matching a given coherent interaction with its corresponding dissipative counterpart; our method generalizes the basic structure used in the theory of ... More
Anomalous mass dimension of multi-flavor QCDOct 08 2016Models of strongly interacting theories with a large mass anomalous dimension ($\gamma_m$) provide an interesting possibility for the dynamical origin of the electroweak symmetry breaking. A laboratory for these models is QCD with many flavors, which ... More
A 125 GeV Scalar Boson and SU(N_{TC})\otimes SU(3)_{{}_{L}}\otimes U(1)_{{}_{X}} modelsMar 16 2013We verify that SU(N)_{{}_{TC}}\otimes SU(3)_{{}_{L}}\otimes U(1)_{{}_{X}} models, where the gauge symmetry breaking is totally dynamical and promoted by the non-Abelian technicolor (TC) group and the strong Abelian interactions, are quite constrained ... More
Mass and width of a composite Higgs bosonFeb 13 2009May 18 2009The scalar Higgs boson mass in a Technicolor model was obtained by Elias and Scadron with the analysis of an homogeneous Bethe-Salpeter equation (BSE), however it was performed before the most recent developments of walking gauge theories. It was not ... More
A dynamical mechanism to explain the top-bottom quark mass hierarchyAug 17 2004Jan 20 2005We discuss the mass splitting between the the top and bottom quarks in a technicolor scenario. The model proposed here contains a left-right electroweak gauge group. An extended technicolor group and mirror fermions are introduced. The top-bottom quark ... More
Entanglement swapping, light cones and elements of realityNov 06 2005Jul 20 2006Recently, a number of two-participant all-versus-nothing Bell experiments have been proposed. Here, we give local realistic explanations for these experiments. More precisely, we examine the scenario where a participant swaps his entanglement with two ... More
Jet radio emission in Cygnus X-1 and its orbital modulationOct 01 2006Dec 22 2006We present results of our detailed theoretical study of the observed orbital modulation of the radio emission in Cyg X-1. The modulation occurs due to free-free absorption in the wind from the companion star varying with the orbital phase, and our results ... More
Geodesics and admissible-path spaces in Carnot GroupsNov 26 2013We study the topology of admissible-loop spaces on a step-two Carnot group G. We use a Morse-Bott theory argument to study the structure and the number of geodesics on G connecting the origin with a 'vertical' point (geodesics are critical points of the ... More
Numerical analysis of renormalon technique in quantum mechanicsNov 29 1996Jul 14 1997We discuss the ways of extracting a low energy scale of an underlying theory using high energy scattering data. Within an exactly solvable model of quantum mechanics we analyze a technique based on introduction of nonperturbative power corrections accounting ... More
Analytical results for $e^+e^-\to t\bar t$ and $γγ\to t\bar t$ observables near the threshold up to the next-to-next-to-leading order of NRQCDApr 08 1999Oct 10 2001We present an analytical description of top-antitop pair production near the threshold in $e^+e^-$ annihilation and $\g\g$ collisions. A set of basic observables considered includes the total cross sections, forward-backward asymmetry and top quark polarization. ... More
Next-to-next-to-leading order relation between $R(e^+e^-\to b\bar b)$ and $Γ_{\rm sl}(b\to clν_l)$ and precise determination of $|V_{cb}|$May 16 1998Oct 30 1998We present the next-to-next-to-leading order relation between the moments of the $\Upsilon$ system spectral density and the inclusive $B$-meson semileptonic width. The perturbative series for the width as an explicit function of the moments is well convergent ... More
Quark-hadron duality for $K^0-\bar{K^0}$ mixingNov 27 1997Long distance contribution to the $K^0-\bar K^0$ mixing is taken into account consistently and the corrections to the naive duality result represented by the famous box diagram are found to be small. Estimates are given in the leading order of the chiral ... More
A scalar gluonium contribution to $K\rightarrowππ$ decayJul 17 1995We study a new $K\rightarrow\pi\pi$ decay channel with gluons in intermediate state which is normally neglected within the factorization framework. Both short-distance and long-distance parts of the amplitude are calculated. The chiral Lagrangian approach ... More
Effects of the stellar wind on X-ray spectra of Cygnus X-3Oct 30 2007Feb 04 2008We study X-ray spectra of Cyg X-3 from BeppoSAX, taking into account absorption and emission in the strong stellar wind of its companion. We find the intrinsic X-ray spectra are well modelled by disc blackbody emission, its upscattering by hot electrons ... More
On open superstring partition function in inhomogeneous rolling tachyon backgroundOct 27 2003Jan 27 2004We consider open superstring partition function Z on the disc in time-dependent tachyon background T= f(x_i) e^{m x_0} where the profile function f depends on spatial coordinates. We compute Z to second order in derivatives of f and compare the result ... More
On gravitational couplings in D-brane actionNov 12 2002Oct 26 2004We compute the two closed string graviton - two open string scalar scattering amplitude on the disc to show that there is no second-derivative curvature - scalar coupling term R X^2 in the low-energy effective action of a D-brane in curved space in type ... More
Coherent effects in double-barrier Josephson junctionsDec 07 1999The general solution for ballistic electronic transport through double-barrier Josephson junctions is derived. We show the existence of a regime of phase-coherent transport in which the supercurrent is proportional to the single barrier transparency and ... More
The origin of the first and third generation fermion masses in a technicolor scenarioFeb 19 2003Jan 22 2004We argue that the masses of the first and third fermionic generations, which are respectively of the order of a few MeV up to a hundred GeV, are originated in a dynamical symmetry breaking mechanism leading to masses of the order $\alpha \mu$, where $\alpha$ ... More
On (non)integrability of classical strings in p-brane backgroundsNov 15 2012Jan 07 2013We investigate the question of possible integrability of classical string motion in curved p-brane backgrounds. For example, the D3-brane metric interpolates between the flat and the AdS_5 x S^5 regions in which string propagation is integrable. We find ... More
On the power of non-local boxesApr 18 2005Nov 07 2005A non-local box is a virtual device that has the following property: given that Alice inputs a bit at her end of the device and that Bob does likewise, it produces two bits, one at Alice's end and one at Bob's end, such that the XOR of the outputs is ... More
Casimir effect for scalar fields under Robin boundary conditions on platesJul 31 2000Oct 22 2001We study the Casimir effect for scalar fields with general curvature coupling subject to mixed boundary conditions $(1+\beta_{m}n^{\mu}\partial_{\mu})\phi =0$ at $x=a_{m}$ on one ($m=1$) and two ($m=1,2$) parallel plates at a distance $a\equiv a_{2}-a_{1}$ ... More
Technicolor models with coupled systems of Schwinger-Dyson equationsFeb 28 2019When Technicolor (TC), QCD, Extended Technicolor (ETC) and other interactions become coupled through their different Schwinger-Dyson equations, the solution of these equations are modified in comparison with the ones of the isolated equations. The change ... More
Exact string background from a WZW model based on the Heisenberg groupMar 07 1994A WZW model for the non-semi-simple D-dimensional Heisenberg group, which directly generalizes the E_{2}^{c} group, is constructed. It is found to correspond to an D-dimensional string background of plane-wave type with physical Lorentz signature D-2. ... More
Notes on non-thermal X-ray radiation of radio supernova remnant W50 and collimated radiation of SS433Jun 19 2013Diffuse X-ray emission of the radio nebula W50 along the line of the of jets of the microquasar SS433 has a non-thermal power law component. This could be the inverse-Compton scattered emission of the SS433 accretion disk funnel, which is collimated in ... More
Next-to-next-to-leading order vacuum polarization function of heavy quark near threshold and sum rules for $b \bar b$ systemMar 16 1998Apr 06 1998A correlator of the vector current of a heavy quark is computed analytically near threshold in the next-to-next-to-leading order in perturbative and relativistic expansion that includes $\al_s^2$, $\al_sv$ and $v^2$ corrections in the coupling constant ... More
Comment on ``Next-to-next-to-leading order vacuum polarization function of heavy quark near threshold and sum rules for $b \bar b$ system'' and ``Next-to-next-to-leading order relation between $R(e^+e^-\to b\bar b)$ and $Γ_{\rm sl}(b\to clν_l)$ and precise ... MoreJan 19 1999The most recent recalculation of the two-loop correction to the static quark-antiquark potential gave the numerical value different from the previously known one. We comment on the effect this change produces on the numerical estimates of the bottom quark ... More
Extended analysis of the "penguin" part of $K\toππ$ amplitudeMar 14 1995We make an attempt to clarify the role of the annihilation or "penguin" mode in the description of the $K\rightarrow\pi\pi$ decay within the Standard Model. The attention is concentrated on new operators in the effective $\Delta S=1$ Hamiltonian and the ... More
Curved space resolution of singularity of fractional D3-branes on conifoldNov 01 2001We construct a supergravity dual to the cascading $SU(N+M) x SU(N)$ supersymmetric gauge theory (related to fractional D3-branes on conifold according to Klebanov et al) in the case when the 3-space is compactified on $S^3$ and in the phase with unbroken ... More
Schwinger-Dyson approach and its application to generate a light composite scalarJan 15 2016Feb 24 2016We discuss the possibility of generating a light composite scalar boson, in a scenario that we may generically call Technicolor, or in any variation of a strongly interacting theory, where by light we mean a scalar composite mass about one order of magnitude ... More
Dynamical gluon mass corrections in heavy quarkonia decaysApr 26 2000Using the expression of the dynamical gluon mass obtained through the operator product expansion we discuss the relevance of gluon mass effects in the decays V -> hadrons (V = J/Psi, Upsilon). Relativistic and radiative corrections are also introduced ... More
Semiclassical rigid strings with two spins in AdS_5Nov 12 2009Semiclassical spinning string states in AdS_5 are, in general, characterised by the three SO(2,4) conserved charges: the energy E and the two spins S_1 and S_2. We discuss several examples of explicit classical solutions for rigid closed strings of (bended) ... More
Search for excited electrons through $γγ$ scatteringAug 10 2012We study the potential of $\gamma \gamma$ option of future high energy linear $e^{+}e^{-}$ colliders to search for excited electrons with spin-1/2. We calculate single production cross sections, give the angular distributions and $f-m^*$ contour plots ... More
Chiral expansion of nucleon PDF at $x\sim m_π/M_N$Nov 14 2013Based on the chiral perturbation theory, we investigate the low-energy dynamics of nucleon parton distributions. We show that in different regions of the momentum fraction $x$ the chiral expansion is significantly different. For nucleon parton distributions ... More
A study of spectra of Cyg X-3 observed by BeppoSAXDec 22 2004Jan 10 2005We model the ~1-200 keV spectra of Cygnus X-3 observed by BeppoSAX. The continuum, modeled by Comptonization in a hybrid plasma, is modified by the strongly ionized plasma of the stellar wind of the Wolf-Rayet companion star. Discrete absorption and emission ... More
Quantum Corrections to Bekenstein-Hawking Black Hole Entropy and Gravity Partition FunctionsApr 25 2013Algebraic aspects of the computation of partition functions for quantum gravity and black holes in $AdS_3$ are discussed. We compute the sub-leading quantum corrections to the Bekenstein-Hawking entropy. It is shown that the quantum corrections to the ... More
Can classical wormholes stabilize the brane-anti-brane system?Sep 09 2003We investigate the static solutions of Callan and Maldecena and Gibbons to lowest order Dirac-Born-Infeld theory. Among them are charged wormhole solutions connecting branes to anti-branes. It is seen that there are no such solutions when the separation ... More
W-Infinity Algebras from Noncommutative Chern-Simons TheoryJun 11 2002May 16 2003We examine Chern-Simons theory written on a noncommutative plane with a `hole', and show that the algebra of observables is a nonlinear deformation of the $w_\infty$ algebra. The deformation depends on the level (the coefficient in the Chern-Simons action), ... More
Gravitation Field Dynamics in Jeans TheoryFeb 02 2016Closed system of time equations for nonrelativistic gravitation field and hydrodynamic medium was obtained by taking into account binary correlations of the field, which is the generalization of Jeans theory. Distribution function of the systemwas built ... More
On some a priori majorant of eigenvalues of Sturm--Liouville problemsFeb 04 2016Let $M_\gamma$ be precise a priori majorant of first eigenvalues of Sturm--Liouville problems $-y"+qy=\lambda y,\quad y(0)=y(1)=0$, where $q\leqslant 0$ and $\int_0^1 |q|^\gamma\,dx=1$, $\gamma\in (0,1/2)$. It is shown that the inequality $M_\gamma<\pi^2$ ... More
Flux Vacua Statistics for Two-Parameter Calabi-Yau'sJul 29 2004Oct 12 2004We study the number of flux vacua for type IIB string theory on an orientifold of the Calabi-Yau expressed as a hypersurface in WCP^4[1,1,2,2,6] by evaluating a suitable integral over the complex-structure moduli space as per the conjecture of Douglas ... More
Matrix Model on Z-OrbifoldMar 24 2002Dec 26 2002Six dimensional compactification of the type IIA matrix model on the ${\bf Z}$-orbifold is studied. Introducing a ${\bf Z}_{3}$ symmetry properly on the three mirror images of fields in the $N$-body system of the supersymmetric D0 particles, the action ... More
Uniform semiglobal practical asymptotic stability for non-autonomous cascaded systems and applicationsMar 02 2005Feb 01 2006It is due to the modularity of the analysis that results for cascaded systems have proved their utility in numerous control applications as well as in the development of general control techniques based on ``adding integrators''. Nevertheless, the standing ... More
The Asymptotics of the Correlations Functions in $(1+1)d$ Quantum Field Theory From Finite Size Effects in Conformal TheoriesJan 08 1992Using the finite-size effects the scaling dimensions and correlation functions of the main operators in continuous and lattice models of 1d spinless Bose-gas with pairwise interaction of rather general form are obtained. The long-wave properties of these ... More
Frustrated trimer chain model and Cu3Cl6(H2O)2 2H8C4SO2 in a magnetic fieldMay 24 2000May 08 2001Recent magnetization and susceptibility measurements on Cu3Cl6(H2O)2 2H8C4SO2 by Ishii et.al. [J. Phys. Soc. Jpn. 69, 340 (2000)] have demonstrated the existence of a spin gap. In order to explain the opening of a spin gap in this copper-trimer system, ... More
Fermi LAT Observations of the Vela PulsarDec 16 2008The Vela pulsar is the brightest persistent source in the GeV sky and thus is the traditional first target for new gamma-ray observatories. We report here on initial Fermi Large Area Telescope observations during verification phase pointed exposure and ... More
Vortex dynamics in nonrelativistic Abelian Higgs modelSep 07 2015Sep 16 2015The dynamics of the gauge vortex with arbitrary form of a contour is considered in the framework of the nonrelativistic Abelian Higgs model, including the possibility of the gauge field interaction with the fermion asymmetric background. The equations ... More
The effective action and equations of motion of curved local and global vortices: Role of the field excitationsOct 06 2008The effective actions for both local and global curved vortices are derived, based on the derivative expansion of the corresponding field theoretic actions of the nonrelativistic Abelian Higgs and Goldstone models. The role of excitations of the modulus ... More
Two-Loop Corrections to Bhabha ScatteringJan 14 2005Jul 04 2005The two-loop radiative photonic corrections to the Bhabha scattering are computed in the leading order of the small electron mass expansion up to nonlogarithmic term. After including the soft photon bremsstrahlung we obtain the infrared finite result ... More
Instantons and Non-Perturbative Dynamics of N=2 Supersymmetric Abelian Gauge Theories in Two DimensionsOct 29 1997Jun 19 1998We study N=2 supersymmetric Abelian gauge model with the Fayet-Iliopoulos term and an arbitrary number of chiral matter multiplets in two dimensions. By analyzing the instanton contribution we compute the non-perturbative corrections to the mass spectrum ... More
Two-Loop Photonic Corrections to Massive Bhabha ScatteringAug 11 2005Nov 28 2005We describe the details of the evaluation of the two-loop radiative photonic corrections to Bhabha scattering. The role of the corrections in the high-precision luminosity determination at present and future electron-positron colliders is discussed.
Top quark threshold production in $γγ$ collisions: current theoretical issuesSep 29 2000The top quark-antiquark pair threshold production at future High Energy Photon Colliders is considered in view of the recent advances in the theoretical description of the nonrelativistic heavy quark dynamics.
Exact unitary transformation for Rashba rings in magnetic and electric fieldsDec 25 2015Jan 05 2016An exact solution for single electron states on mezoscopic rings with the Rashba coupling and in the presence of external magnetic and electric fields is derived by means of a unitary transformation. The transformation maps the model to a bare ring, which ... More
Comment on the "Decrease of the surface resistance in superconducting niobium resonator cavities by the microwave field"May 12 2014In a recent publication [Appl. Phys. Lett. 104, 092601 (2014)] Ciovati et al. claim that: 1) thermal effects were disregarded in our original work [*]; 2) increase of $Q$ at $T=2$ K up to about $B\sim$100 mT in nitrogen doped cavities is just an extended ... More
Stochastic Inflation: New ResultsJun 14 1994This is an old article which has never been posted for public use and which only appeard in a relatively hard-to-get Proceedings of the Sakharov Conference in Moscow (May, 1991). The subject of this article has received a lot of attention in last two ... More
Logarithmic Potential Model of Quigg and Rosner as a Generalization of Naive Quark ModelJun 26 2000Exploiting the explicit mass formulae for logarithmic potential model of Quigg and Rosner it is shown that at least on the level of mass-relations this model reproduces the naive quark model relations and generalizes the last one in case of highly non-trivial ... More
Global anomaly and a family of structures on fold product of complex two-cyclesOct 27 2009We propose a new set of IIB type and eleven-dimensional supergravity solutions which consists of the $n$-fold product of two-spaces ${\bf H}^n/\Gamma$ (where ${\bf H}^n$ denotes the product of $n$ upper half-planes $H^2$ equipped with the co-compact action ... More
Universal Racah matrices and adjoint knot polynomials. I. Arborescent knotsNov 29 2015By now it is well established that the quantum dimensions of descendants of the adjoint representation can be described in a universal form, independent of a particular family of simple Lie algebras. The Rosso-Jones formula then implies a universal description ... More
Proving AGT relations in the large-c limitSep 18 2009In the limit of large central charge $c$ the 4-point Virasoro conformal block becomes a hypergeometric function. It is represented by a sum of chiral Nekrasov functions, which can also be explicitly evaluated. In this way the known proof of the AGT relation ... More
The Power of Nekrasov FunctionsAug 15 2009The recent AGT suggestion to use the set of Nekrasov functions as a basis for a linear decomposition of generic conformal blocks works very well not only in the case of Virasoro symmetry, but also for conformal theories with extended chiral algebra. This ... More
p,q-Duality and Hamiltonian Flows in the Space of Integrable Systems or Integrable Systems as Canonical Transforms of the Free OnesJul 12 2001Jan 09 2002Variation of coupling constants of integrable system can be considered as canonical transformation or, infinitesimally, a Hamiltonian flow in the space of such systems. Any function $T(\vec p, \vec q)$ generates a one-parametric family of integrable systems ... More
On Renormalization Group in Abstract QFTMay 30 2000The basics of RG equations for generic partition functions are briefly reviewed, keeping in mind an application to the Polyakov-de Boer-Verlindes description of the holomorphic RG flow.