Results for "A. Grassellino"

total 196357took 0.11s
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
Dependence of the microwave surface resistance of superconducting niobium on the magnitude of the rf fieldApr 16 2013Utilizing difference in temperature dependencies we decoupled BCS and residual components of the microwave surface resistance of superconducting niobium at all rf fields up to $B_\mathrm{rf}\sim110$ mT. We reveal that the residual resistance decreases ... More
Achievement of Ultra-High Quality Factor in Prototype Cryomodule for LCLS-IIDec 21 2018Jan 08 2019Quality factor is a primary cost driver for high energy, continuous wave (CW) SRF linacs like the LCLS-II X-ray free electron laser currently under construction. Taking this into account, several innovations were introduced in the LCLS-II cryomodule design ... More
Nitrogen and argon doping of niobium for superconducting radio frequency cavities: a pathway to highly efficient accelerating structuresJun 03 2013Jun 24 2013We report a surface treatment that systematically improves the quality factor of niobium radio frequency cavities beyond the expected limit for niobium. A combination of annealing in a partial pressure of nitrogen or argon gas and subsequent electropolishing ... More
Low RF power plasma ignition and detection for in-situ cleaning of 1.3 GHz 9-cell cavitiesFeb 08 2019Superconducting Radio Frequency (SRF) cavities performance preservation is crucial, from vertical test to accelerator operation. Field Emission (FE) is still one of the performance limiting factors to overcome and plasma cleaning has been proven successful ... More
The Role of Magnetic Flux Expulsion to Reach Q0>3x10^10 in SRF CryomodulesDec 10 2018When a superconducting radiofrequency cavity is cooled through its critical temperature, ambient magnetic flux can become "frozen in" to the superconductor, resulting in degradation of the quality factor. This is especially problematic in applications ... More
Fermilab experience of post-annealing losses in SRF niobium cavities due to furnace contamination and the ways to its mitigation: a pathway to processing simplification and quality factor improvementMay 09 2013May 16 2013We investigate the effect of high temperature treatments followed by only high-pressure water rinse (HPR) of superconducting radio frequency (SRF) niobium cavities. The objective is to provide a cost effective alternative to the typical cavity processing ... More
Accelerating fields up to 49 MV/m in TESLA-shape superconducting RF niobium cavities via 75C vacuum bakeJun 26 2018In this paper we present the discovery of a new surface treatment applied to superconducting radio frequency (SRF) niobium cavities, leading to unprecedented accelerating fields of 49 MV/m in TESLA-shaped cavities, in continuous wave (CW); the corresponding ... More
Proximity breakdown of hydrides in superconducting niobium cavitiesDec 14 2012Jan 13 2013Many modern and proposed future particle accelerators rely on superconducting radio frequency cavities made of bulk niobium as primary particle accelerating structures. Such cavities suffer from the anomalous field dependence of their quality factors ... More
Dependence of the residual surface resistance of superconducting RF cavities on the cooling dynamics around $T_\mathrm{c}$Jan 30 2014Mar 07 2014We report a strong effect of the cooling dynamics through $T_\mathrm{c}$ on the amount of trapped external magnetic flux in superconducting niobium cavities. The effect is similar for fine grain and single crystal niobium and all surface treatments including ... More
Ultra-high quality factors in superconducting niobium cavities in ambient magnetic fields up to 190 mGOct 29 2014Ambient magnetic field, if trapped in the penetration depth, leads to the residual resistance and therefore sets the limit for the achievable quality factors in superconducting niobium resonators for particle accelerators. Here we show that a complete ... More
Strong Meissner screening change in superconducting radio frequency cavities due to mild bakingNov 27 2013We investigate "hot" regions with anomalous high field dissipation in bulk niobium superconducting radio frequency cavities for particle accelerators by using low energy muon spin rotation (LE-$\mu$SR) on corresponding cavity cutouts. We demonstrate that ... More
Cooling Dynamics Through Transition Temperature of Niobium SRF Cavities Captured by Temperature MappingApr 17 2015Apr 20 2015Cool-down dynamics of superconducting accelerating cavities became particularly important for obtaining very high quality factors in SRF cavities. Previous studies proved that when cavity is cooled fast, the quality factor is higher than when cavity is ... More
Magnetic Flux Dynamics in Horizontally Cooled Superconducting CavitiesFeb 25 2015Apr 17 2015Previous studies on magnetic flux expulsion as a function of cooling details have been performed for superconducting niobium cavities with the cavity beam axis placed parallel respect to the helium cooling flow, and findings showed that for sufficient ... More
Muon spin rotation studies of niobium for superconducting RF applicationsMar 26 2013Mar 31 2013In this work we investigate superconducting properties of niobium samples via application of the muon spin rotation/relaxation (muSR) technique. We employ for the first time the muSR technique to study samples that are cutout from large and small grain ... More
Effect of interstitial impurities on the field dependent microwave surface resistance of niobiumJun 13 2016Previous work has demonstrated that the radio frequency surface resistance of niobium resonators is dramatically reduced when nitrogen impurities are dissolved as interstitial in the material. The origin of this effect is attributed to the lowering of ... More
Commissioning And First Results From The Fermilab Cryomodule Test StandMay 07 2018A new test stand dedicated to Superconducting Radiofrequency (SRF) cryomodule testing, CMTS1, has been commissioned and is now in operation at Fermilab. The first device to be cooled down and powered in this facility is the prototype 1.3 GHz cryomodule ... More
Quench-Induced Degradation of the Quality Factor in Superconducting ResonatorsMay 01 2016Quench of superconducting radio-frequency cavities frequently leads to the lowered quality factor Q0, which had been attributed to the additional trapped magnetic flux. Here we demonstrate that the origin of this magnetic flux is purely extrinsic to the ... More
Efficient expulsion of magnetic flux in superconducting RF cavities for high $Q_0$ applicationsSep 14 2015Feb 13 2016Even when cooled through its transition temperature in the presence of an external magnetic field, a superconductor can expel nearly all external magnetic flux. This Letter presents an experimental study to identify the parameters that most strongly influence ... More
Frequency dependence of trapped flux sensitivity in SRF cavitiesNov 16 2017In this letter, we present the frequency dependence of the vortex surface resistance of bulk niobium accelerating cavities as a function of different state-of-the-art surface treatments. Higher flux surface resistance per amount of trapped magnetic field ... More
Nitrogen-Doped 9-Cell Cavity Performance in a Test Cryomodule for LCLS-IINov 06 2014Nov 13 2014The superconducting RF linac for LCLS-II calls for 1.3 GHz 9-cell cavities with an average intrinsic quality factor Q0 of 2.7x10^10 at 2 K and 16 MV/m accelerating gradient. Two niobium 9-cell cavities, prepared with nitrogen-doping at Fermilab, were ... 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
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
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
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
Can Electro-Weak $\h$-Term be Observable ?May 14 1993We rederive and discuss the result of the previous paper that in the standard model $\theta$-term related to $W$-boson field can not be induced by weak instantons. This follows from the existence of the fermion zero mode in the instanton field even when ... More
Ambiguity-free formulation of the Higgs-Kibble modelOct 05 2010A renormalizable ambiguity-free formulation of the Higgs-Kibble model is proposed.
Quantum-Limited Amplification via Reservoir EngineeringNov 01 2013Apr 08 2014We describe a new kind of phase-preserving quantum amplifier which utilizes dissipative interactions in a parametrically-coupled three-mode bosonic system. The use of dissipative interactions provides a fundamental advantage over standard cavity-based ... More
Crossed Andreev reflection in diffusive contactsNov 06 2006Crossed Andreev reflection in multiterminal structures in the diffusive regime is addressed within the quasiclassical Keldysh-Usadel formalism. The elastic cotunneling and crossed Andreev reflection of quasiparticles give nonlocal currents and voltages ... More
Light composite scalar boson from a see-saw mechanism in two-scale TC modelsJun 25 2015We consider the possibility of a light composite scalar boson arising from mass mixing between a relatively light and heavy scalar singlets in a see-saw mechanism expected to occur in two-scale Technicolor (TC) models. A light composite scalar boson can ... More
Limit on the fermion masses in technicolor modelsAug 21 2003Recently it has been pointed out that no limits can be put on the scale of fermion mass generation $(M)$ in technicolor models, because the relation between the fermion masses $(m_f)$ and $M$ depends on the dimensionality of the interaction responsible ... More
Dynamical Symmetry Breaking in a Minimal 3-3-1 ModelOct 11 2012The gauge symmetry breaking in some versions of 3-3-1 models can be implemented dynamically because at the scale of a few TeVs the $U(1)_X$ coupling constant becomes strong. In this work we consider the dynamical symmetry breaking in a minimal $SU(3)_{{}_{TC}}\times ... More
Energy criterion to select the behavior of dynamical masses in technicolor modelsMay 05 2002We propose a quite general ansatz for the dynamical mass in technicolor models. We impose on this ansatz the condition for formation of the tightest composite boson state, or the criterion that it should lead to the deepest minimum of energy. This criterion ... More
Quantum corrections to energy of short spinning string in AdS5Jun 29 2008Feb 02 2009Motivated by desire to shed light on the strong coupling behaviour of anomalous dimensions of "short" gauge theory operators we consider the famous example of folded spinning string in AdS_5 in the limit of small semiclassical spin parameter \S = S/sqrt[lambda]. ... More
New results for the missing quantum numbers labeling the quadrupole and octupole boson basisMay 24 2004Oct 27 2004The many $2^k$-pole boson states, $|N_kv_k\alpha_k I_kM_k>$ with $k=2,3$, realize the irreducible representation (IR) for the group reduction chains $SU(2k+1)\supset R_{2k+1}\supset R_3\supset R_2$. They have been analytically studied and widely used ... More
A statistical model of three-dimensional anisotropy and intermittency in strong Alfvénic turbulenceMay 24 2016We propose a simple statistical model of three-dimensionally anisotropic, intermittent, strong Alfv\'enic turbulence, incorporating both critical balance and dynamic alignment. Our model is based on log-Poisson statistics for Elsasser-field increments ... More
One- and many-body effects on mirages in quantum corralsAug 27 2002May 23 2003Recent interesting experiments used scanning tunneling microscopy to study systems involving Kondo impurities in quantum corrals assembled on Cu or noble metal surfaces. The solution of the two-dimensional one-particle Schrodinger equation in a hard wall ... More
Thin topological insulator film in a perpendicular magnetic fieldMar 10 2011May 10 2011We report on a study of an ultrathin topological insulator film with hybridization between the top and bottom surfaces, placed in a quantizing perpendicular magnetic field. We calculate the full Landau level spectrum of the film as a function of the applied ... More
Practical techniques of QCD vs exact results of solvable modelsDec 30 1996Jul 14 1997We check quantitatively the validity of some popular phenomenological approaches of QCD in simple models. Dispersion sum rules are considered within the ladder approximation of a field-theoretic model with OPE given by ordinary loop diagrams which are ... More
Bottom quark pole mass and $|V_{cb}|$ matrix element from $R(e^+e^-\to b\bar b)$ and $Γ_{sl}(b\to clν_l)$ in the next-to-next-to-leading orderJul 20 1998Mar 19 1999We present a consistent analysis of $\Upsilon$ sum rules and $B$-meson semileptonic width in the next-to-next-to-leading order in the strong coupling constant. The analysis is based on the analytical result for the heavy quark vector current correlator ... 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
Graph homology: Koszul and Verdier dualityFeb 12 2007We show that Verdier duality for certain sheaves on the moduli spaces of graphs associated to Koszul operads corresponds to Koszul duality of operads. This in particular gives a conceptual explanation of the appearance of graph cohomology of both the ... 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
Semiclassical strings in AdS_5 x S^5 and scalar operators in N=4 SYM theoryJul 26 2004Sep 14 2004We review recent progress in checking AdS/CFT duality in the sector of ''semiclassical'' string states dual to ''long'' scalar operators of N=4 super Yang-Mills theory. In particular, we discuss the effective action approach, in which the same sigma model ... More
Interactions Between Branes and Matrix TheoriesSep 16 1997Oct 06 1997We review some tests of the 0-brane and instanton matrix models based on comparing long-distance interaction potentials between branes and their bound states (with 1/2,1/4 or 1/8 of supersymmetry) in supergravity and in super Yang-Mills descriptions. ... More
No-force condition and BPS combinations of p-branes in 11 and 10 dimensionsSep 26 1996Dec 05 1996The condition of vanishing of static force on a q-brane probe in the gravitational background produced by another p-brane is used to give a simple derivation of the pair-wise intersection rules which govern the construction of BPS combinations of branes. ... More
On singularities of spherically symmetric backgrounds in string theorySep 08 1995We suggest that for singular rotationally invariant closed string backgrounds which need sources for their support at the origin (in particular, for special plane waves and fundamental strings) certain `trivial' \a'-corrections (which are usually ignored ... More
Closed strings in uniform magnetic field backgroundsMay 23 1995We consider a class of conformal models describing closed strings in axially symmetric stationary magnetic flux tube backgrounds. These models are closed string analogs of the Landau model of a particle in a magnetic field or the model of an open string ... More
String cosmology and dilatonJun 17 1992We discuss some aspects of string cosmology with an emphasis on the role played by the dilaton. A cosmological scenario based on the assumption that all spatial dimensions are periodic so that winding modes play an important role is reviewed. A possibility ... More
On limits of superstring in AdS_5 x S^5Jan 15 2002Jan 16 2002The superstring action in AdS_5 x S^5 depends on two parameters: the inverse string tension a' and the radius R. The standard AdS/CFT correspondence requires that the string coordinates are rescaled so that the action depends only on one combination of ... More
Harmonic superpositions of M-branesApr 07 1996Jun 05 1996We present solutions describing supersymmetric configurations of 2 or 3 orthogonally intersecting 2-branes and 5-branes of D=11 supergravity. The configurations which preserve 1/4 or 1/8 of maximal supersymmetry are 2+2, 5+5, 2+5, 2+2+2, 5+5+5, 2+2+5 ... More
Generalised chiral null models and rotating string backgroundsMar 15 1996We consider an extension of a special class of conformal sigma models (`chiral null models') which describe extreme supersymmetric string solutions. The new models contain both `left' and `right' vector couplings and should correspond to non-BPS backgrounds. ... More
Dilaton, winding modes and cosmological solutionsDec 03 1991We review some formal aspects of cosmological solutions in closed string theory with duality symmetric ``matter'' following recent paper with C. Vafa (HUTP-91/A049). We consider two models : when the matter action is the classical action of the fields ... More
Covariant Hamiltonian first order field theories with constraints on manifolds with boundary: the case of Hamiltonian dynamicsNov 10 2015Inspired by problems arising in the geometrical treatment of Yang-Mills theories and Palatini's gravity, the covariant formulation of Hamiltonian dynamical systems as a Hamiltonian field theory of dimension $1+0$ on a manifold with boundary is discussed. ... More
On the Recent Results of E835 Experiment at FNALNov 28 2003Feb 06 2004In this note we briefly concern several recent results of E835 Experiment at FNAL that are discussed in the framework of unified picture on hadronic spectra elaborated in our early works. It has been established that new E835 Collaboration results provided ... More
An achromatic polarization retarder realized with slowly varying linear and circular birefringenceMay 02 2011Using the phenomena of linear and circular birefringence we propose a device that can alter general elliptical polarization of a beam by a predetermined amount, thereby allowing conversion between linearly-polarized light and circularly polarized light ... More
Axial Magnetostatics of a Ring Current in a Kerr FieldFeb 19 2002Feb 20 2002The electromagnetic fields generated by a ring current around a Kerr black hole have been found. The acceleration of a charged particle by a force electric field along the rotation axis is investigated in the constructed model, as applied to the astrophysics ... More
Conceptual design of a scalable multi-kton superconducting magnetized liquid Argon TPCOct 11 2005We discuss the possibility of new generation neutrino and astroparticle physics experiments exploiting a superconducting magnetized liquid Argon Time Projection Chamber (LAr TPC). The possibility to complement the features of the LAr TPC with those provided ... More
Ideas for future liquid Argon detectorsSep 13 2004We outline a strategy for future experiments on neutrino and astroparticle physics based on the use, at different detector mass scales (100 ton and 100 kton), of the liquid Argon Time Projection Chamber (LAr TPC) technique. The LAr TPC technology has ... More
Finite Temperature Reduction of the SU(2) Higgs-Model with Complete Static BackgroundMay 31 1994Direct evaluation of the 1-loop fluctuation determinant of non-static degrees of freedom in a complete static background is advocated to be more efficient for the determination of the effective three-dimensional model of the electroweak phase transition ... More
Condensates and instanton - torus knot duality. Hidden Physics at UV scaleDec 29 2014Aug 16 2015We establish the duality between the torus knot superpolynomials or the Poincar\'e polynomials of the Khovanov homology and particular condensates in $\Omega$-deformed 5D supersymmetric QED compactified on a circle with 5d Chern-Simons(CS) term. It is ... More
From Yang-Mills Lagrangian to MHV DiagramsOct 14 2005Jan 18 2006We prove the equivalence of a recently suggested MHV-formalism to the standard Yang-Mills theory. This is achieved by a formally non-local change of variables. In this note we present the explicit formulas while the detailed proofs are postponed to a ... More
Phenomenological Lagrangians, gauge models and branesApr 03 2016May 18 2016Phenomenological Lagrangians for physical systems with spontaneously broken symmetries are reformulated in terms of gauge field theory. Description of the Dirac $p$-branes in terms of the Yang-Mills-Cartan gauge multiplets interacting with gravity, is ... More
On the cancellation of 4-derivative terms in the Volkov-Akulov actionMar 22 2010Sep 01 2010Recently Kuzenko and McCarty observed the cancellation of 4-derivative terms in the $D=4 {\cal N}=1$ Volkov-Akulov supersymmetric action for the fermionic Nambu-Goldstone field. Here is presented a simple algebraic proof of the cancellation based on using ... More
Tension as a Perturbative Parameter in Non--Linear String Equations in Curved Space--TimeJun 04 1996A perturbation theory with respect to tension parameter $\gamma/\alpha^\prime$ for the non--linear equations of string, moving in curved space--time is considered. Obtained are linearized motion equations for the functions of the $n-$th degree of approximation ... More
Gauge theory approach to branes and spontaneous symmetry breakingSep 01 2015Apr 08 2016Gauge theory approach to consideration of the Nambu-Goldstone bosons as gauge and vector fields represented by the Cartan forms of spontaneously broken symmetries, is discussed. The approach is generalized to describe the fundamental branes in terms of ... More
On brane symmetriesSep 23 2014The geometric approach to branes is reformulated in terms of gauge vector fields interacting with massless tensor multiplets in gravitational backgrounds
Gauge fields beyond perturbation theoryOct 30 2013A new formulation of nonabelian gauge theories, introducing new ghost fields and new symmetry is proposed. This formulation does not suffer from Gribov ambiguity and allows to quantize nonabelian gauge fields beyond perturbation theory.
Chiral symmetry in lattice QCDOct 30 2000A chiral invariant effective action for lattice QCD is proposed. Its connection to the multifermion model is established. A possibility of using this action for computer simulations is discussed.
Decoupling of the longitudinal polarization of the vector field in the massless Higgs-Kibble modelMay 28 2012It is shown that the three dimensionally longitudinal component of the vector field decouples in the massless limit of nonabelian Higgs model.
Higgs mechanism as a collective effect due to extra dimensionApr 07 2006A systematic analysis of the unitary electroweak model described by the higher derivative Lagrangian depending on extra dimension [1] is presented.
Gauge invariance of dimension two condensate in Yang-Mills theoryJul 22 2004Gauge independence of dimension two condensate in Yang-Mills theory is demonstrated by using a noncommutative theory technique.
Renormalization by enforcing a symmetryApr 26 2001A new renormalization scheme for theories with nontrivial internal symmetry is proposed. The scheme is regularization independent and respects the symmetry requirements.
Negative longitudinal magnetoresistance in Dirac and Weyl metalsMay 07 2015Jun 29 2015It has recently been found that Dirac and Weyl metals are characterized by an unusual weak-field longitudinal magnetoresistance: large, negative, and quadratic in the magnetic field. This has been shown to arise from chiral anomaly, i.e. nonconservation ... More
Binary life after the AGB - towards a unified pictureDec 15 2006A unified evolutionary scheme that includes post-AGB systems, barium stars, symbiotics, and related systems, explaining their similarites as well as differences. Can we construct it? We compare these various classes of objects in order to construct a ... More
Radius & Distance Estimates of the Isolated Neutron Stars Geminga & PSR B0656+14 using Optical PhotometryDec 10 1998Integrated ground-based and HST optical studies of isolated neutron stars have provided important independent datasets in the determination of emission activity, particularly in the fitting of anticipated Rayleigh-Jeans extrapolations from EUV/soft X-ray ... More
On Lagrangian formulations for mixed-symmetry HS fields on AdS spaces within BFV-BRST approachSep 28 2008Oct 03 2008The key aspects of a gauge-invariant Lagrangian description of massive and massless half-integer higher-spin fields in AdS spaces with a two-row Young tableaux $Y(s_1,s_2)$ are presented in an unconstrained description, as well as in off-shell formulations ... More
General Superfield Quantization Method. III. Construction of Quantization SchemeApr 16 2003Extension procedure for supermanifold ${\cal M}_{cl}$ of superfields ${\cal A}^{\imath}(\theta)$, ghost number construction are considered. Classical and $\hbar$-deformed generating (master) equations, existence theorems for their solutions are formulated ... More
Multiplier Hopf group coalgebras from algebraic and analytical point of viewsAug 02 2005Aug 07 2005The Multiplier Hopf Group Coalgebra was introduced by Hegazi in 2002 [7] as a generalization of Hope group caolgebra, introduced by Turaev in 2000 [5], in the non-unital case. We prove that the concepts introduced by A.Van Daele in constructing multiplier ... More
Galactic origin of ultrahigh energy cosmic raysFeb 16 2009The arrival directions of ultrahigh energy extensive air showers (EAS) by Yakutsk, AGASA, P. Auger array data are analyzed. For the first time, the maps of equal exposition of celestial sphere for the distribution of particles by AGASA and P. Auger arrays ... More
Particles Flux of Ultrahigh Energy from a Galactic PlaneJan 16 2012Arrival directions of particles were analyzed according to the arrays of extensive air showers (EAS) data. A new method of sources search and anisotropy of arrival directions particles is suggested. There was found the particles flux of ultrahigh energy ... More
Entropy current for the relativistic Kadanoff-Baym equation and H-theorem in $O(N)$ theory with NLO self-energy of $1/N$ expansionJun 06 2010We derive an expression of the kinetic entropy current in the nonequilibrium $O(N)$ scalar theory from the Schwinger-Dyson (Kadanoff-Baym) equation with the 1st order gradient expansion. We show that our kinetic entropy satisfies the H-theorem for the ... More
Mean Field Renormalization Group for the Boundary Magnetization of Strip ClustersJul 13 1993We analyze in some detail a recently proposed transfer matrix mean field approximation which yields the exact critical point for several two dimensional nearest neighbor Ising models. For the square lattice model we show explicitly that this approximation ... More
Landau-Khalatnikov-Fradkin Transformations and the Fermion Propagator in Quantum ElectrodynamicsJun 26 2002We study the gauge covariance of the massive fermion propagator in three as well as four dimensional Quantum Electrodynamics (QED). Starting from its value at the lowest order in perturbation theory, we evaluate a non-perturbative expression for it by ... More
Transgression on Hyperkähler Manifolds and Generalized Higher Torsion FormsDec 26 2000We propose a generalization of the Hodge $dd_c$-lemma to the case of hyperk\"ahler manifolds. As an application of this result we derive the global construction of the fourth order transgression of the Chern character forms of hyperholomorphic bundles ... More
A computer proof of a polynomial identity implying a partition theorem of GoellnitzFeb 14 2001In this paper we give a computer proof of a new polynomial identity, which extends a recent result of Alladi and the first author. In addition, we provide computer proofs for new finite analogs of Jacobi and Euler formulas. All computer proofs are done ... More
On Generalized $h$--Vectors of Rational Polytopes with a Symmetry of Prime OrderJul 13 1998We prove tight lower bounds for the coefficients of the generalized $h$-vector of a rational polytope with a symmetry of prime order that is fixed--point--free on the boundary. These bounds generalize results of R.~Stanley and R.~Adin for the $h$--vector ... More
A search for exact superstring vacuaAug 23 1993We investigate $2d$ sigma-models with a $2+N$ dimensional Minkowski signature target space metric and Killing symmetry, specifically supersymmetrized, and see under which conditions they might lead to corresponding exact string vacua. It appears that ... More
Topological SemimetalsOct 25 2016Topological semimetals and metals have emerged as a new frontier in the field of quantum materials. Novel macroscopic quantum phenomena they exhibit are not only of fundamental interest, but may hold some potential for technological applications.
The thermodynamics of urban population flowsJun 29 2012Orderliness, reflected via mathematical laws, is encountered in different frameworks involving social groups. Here we show that a thermodynamics can be constructed that macroscopically describes urban population flows. Microscopic dynamic equations and ... More
Scale-invariance underlying the logistic equation and its social applicationsApr 11 2012On the basis of dynamical principles we derive the Logistic Equation (LE), widely employed (among multiple applications) in the simulation of population growth, and demonstrate that scale-invariance and a mean-value constraint are sufficient and necessary ... More
Variational Principle underlying Scale Invariant Social SystemsApr 11 2012MaxEnt's variational principle, in conjunction with Shannon's logarithmic information measure, yields only exponential functional forms in straightforward fashion. In this communication we show how to overcome this limitation via the incorporation, into ... More
Numerical solution of the Boltzmann equation for the shock wave in a gas mixtureMar 13 2014We study the structure of a shock wave for a two-, three- and four-component gas mixture on the basis of numerical solution of the Boltzmann equation for the model of hard sphere molecules. For the evaluation of collision integrals we use the Conservative ... More
On the problem of the interpretation of quantum physicsApr 10 2014Current thinking on the interpretation of quantum physics is reviewed, with special detail given to the Copenhagen and Everett many-worlds interpretations.
Spontaneous breaking of symmetry of the gravitons of the long wave spectrum in the early UniverseMay 07 2009It is shown that nonlinear terms in equations of gravitons on the background of curved space-time of the expanding Universe can solve the problem of the negative square of the effective mass formally arising in linear approximation for gravitons. Similar ... More