Results for "Agnieszka Cichy"

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The influence of magnetic field on the superconducting properties and the BCS-BEC crossover in systems with local fermion pairingSep 25 2013The aim of this Ph.D. thesis was to investigate superconducting properties in the presence of Zeeman magnetic field in systems with local fermion pairing on the lattice. The study also concerned the evolution from the weak coupling (BCS-like) limit to ... More
Lattice Hamiltonian approach to the massless Schwinger model: precise extraction of the mass gapNov 27 2012Feb 12 2013We present results of applying the Hamiltonian approach to the massless Schwinger model. A finite basis is constructed using the strong coupling expansion to a very high order. Using exact diagonalization, the continuum limit can be reliably approached. ... More
On the Imbalanced d-wave Superfluids within the Spin Polarized Extended Hubbard Model: Weak Coupling LimitSep 25 2013We investigate the superfluid properties of d-wave pairing symmetry within the Extended Hubbard Model (EHM) in a magnetic field. We analyze the temperature and magnetic field dependencies of the order parameter. We find that in the two-dimensional case, ... More
On the BCS-BEC crossover in the Spin-Polarized Attractive Hubbard Model at T=0Sep 25 2013The influence of the Zeeman magnetic field ($h$) on the ground state evolution of superfluid properties from the weak coupling (BCS like) to the strong coupling limit of tightly bound local pairs (LP) with increasing attraction has been studied. The analysis ... More
Orbital magnetism of ultracold fermionic gases in a lattice: dynamical mean-field approachFeb 25 2016May 29 2016We study finite-temperature properties of ultracold four-component mixtures of alkaline-earth-like atoms in optical lattices that can be effectively described by the two-band spin-$1/2$ Hubbard model including the Hund's exchange coupling term. Our main ... More
On the BCS-BEC crossover in the 2D Asymmetric Attractive Hubbard ModelSep 25 2013We analyze the evolution from the weak coupling (BCS-like limit) to the strong coupling limit of tightly bound local pairs (LP's) in the 2D asymmetric attractive Hubbard model, in the presence of the Zeeman magnetic field ($h$). The broken symmetry Hartree ... More
Lattice Hamiltonian approach to the Schwinger model: further results from the strong coupling expansionOct 28 2014Oct 29 2014We employ exact diagonalization with strong coupling expansion to the massless and massive Schwinger model. New results are presented for the ground state energy and scalar mass gap in the massless model, which improve the precision to nearly $10^{-9} ... More
Stability of superfluid phases in the 2D Spin-Polarized Attractive Hubbard ModelSep 25 2013We study the evolution from the weak coupling (BCS-like limit) to the strong coupling limit of tightly bound local pairs (LP's) with increasing attraction, in the presence of the Zeeman magnetic field ($h$) for $d=2$, within the spin-polarized attractive ... More
A comparison of the cut-off effects for Twisted Mass, Overlap and Creutz fermions at tree-level of Perturbation TheoryNov 04 2008In this paper we investigate the cutoff effects at tree-level of perturbation theory for three different lattice regularizations of fermions -- maximally twisted mass Wilson, overlap and Creutz fermions. We show that all three kinds of fermions exhibit ... More
Suppression and revival of long-range ferromagnetic order in the multiorbital Fermi-Hubbard modelFeb 08 2018By means of dynamical mean-field theory allowing for complete account of SU(2) rotational symmetry of interactions between spin-1/2 particles, we observe a strong effect of suppression of ferromagnetic order in the multiorbital Fermi-Hubbard model in ... More
Quark mass anomalous dimension and $Λ_{\overline{\textrm{MS}}}$ from the twisted mass Dirac operator spectrumNov 14 2013Jul 29 2014We investigate whether it is possible to extract the quark mass anomalous dimension and its scale dependence from the spectrum of the twisted mass Dirac operator in Lattice QCD. The answer to this question appears to be positive, provided that one goes ... More
Application of Contractor Renormalization Group (CORE) to the Heisenberg zig-zag and the Hubbard chainMay 14 2008The COntractor REnormalization group method was devised in 1994 by Morningstar and Weinstein. It was primarily aimed at extracting the physics of lattice quantum field theories (like lattice Quantum Chromodynamics). However, it is a general method of ... More
No entire function with real multipliers in class SJul 18 2012We prove that there is no entire transcendental function in class S with real multipliers of all repelling periodic orbits.
DG quivers of smooth rational surfacesJan 27 2013Let X be a smooth rational surface. We calculate a DG quiver of a full exceptional collection of line bundles on X obtained by an augmentation from a strong exceptional collection on the minimal model of X. In particular, we calculate canonical DG algebras ... More
$N_f = 2+1+1$ flavours of twisted mass quarks: cut-off effects at tree-level of perturbation theoryDec 22 2010Jan 30 2011We present a calculation of cut-off effects at tree-level of perturbation theory for the K and D mesons using the twisted mass formulation of lattice QCD. The analytical calculations are performed in the time-momentum frame. The relative sizes of cut-off ... More
Nucleosynthesis of elements in gamma ray bursts enginesJun 17 2014Sep 29 2016We consider the gamma ray burst (GRB) central engine that is powered by the collapse of a massive rotating star or compact binary merger. The engine is a hot and dense accretion disk, which is composed of free nucleons, electron-positron pairs, and helium, ... More
Dipole model analysis of the new HERA I+II dataAug 04 2016We use the dipole model to analyze the inclusive DIS cross section data, obtained from the HERA I+II measurements \cite{Abramowicz:2015mha}. We show that these combined data are very well described within the dipole model framework, which is complemented ... More
A Parallel Algorithm to Test Chordality of GraphsAug 25 2015We present a simple parallel algorithm to test chordality of graphs which is based on the parallel Lexicographical Breadth-First Search algorithm. In total, the algorithm takes time O(N ) on N-threads machine and it performs work O(N 2 ) , where N is ... More
Geometric Algebra Model of Distributed RepresentationsMar 30 2010Formalism based on GA is an alternative to distributed representation models developed so far --- Smolensky's tensor product, Holographic Reduced Representations (HRR) and Binary Spatter Code (BSC). Convolutions are replaced by geometric products, interpretable ... More
Modification of the pi-omega-rho vertex in nuclear medium and its influence on the dilepton production rate in relativistic heavy-ion collisionsNov 19 2004In this PhD thesis we analyze the medium modification of the pi-omega-rho coupling and subsequently discuss its possible influence on the dilepton production rate in relativistic heavy-ion collisions. The first part of the thesis is devoted to the medium ... More
The BCS-BEC crossover and superconductivity in a lattice fermion model with hard core repulsionAug 11 2008We have considered the BCS-BEC crossover at T=0 in the framework of a lattice fermion model (the extended Hubbard model). We have analyzed the case of on-site hard core repulsion ($U=\infty$) and intersite attraction ($W<0$) in a 3D system with extended ... More
A continuum individual based model of fragmentation: dynamics of correlation functionsOct 26 2015An individual-based model of an infinite system of point particles in $\mathbb{R}^d$ is proposed and studied. In this model, each particle at random produces a finite number of new particles and disappears afterwards. The phase space for this model is ... More
Misiurewicz parameters for Weierstrass elliptic functions based on triangle and square latticesDec 23 2013For two families of Weierstrass elliptic functions - based on triangular or square lattices - we prove that the set of Misiurewicz parameters has the Lebesgue measure zero in C.
DG categories and exceptional collectionsMay 28 2012Jan 21 2013Bondal and Kapranov describe how to assign to a full exceptional collection on a variety X a DG category C such that the bounded derived category of coherent sheaves on X is equivalent to the bounded derived category of C. In this paper we show that the ... More
Hardy spaces for the Dunkl harmonic oscillatorFeb 23 2018Apr 14 2018Let $\Delta$ and $L=\Delta -\|\mathbf x\|^2$ be the Dunkl Laplacian and the Dunkl harmonic oscillator respectively. We define the Hardy space $\mathcal H^1$ associated with the Dunkl harmonic oscillator by means of the nontangential maximal function with ... More
Response to rebuttal to Comment on Letter "Excitons in Molecular Aggregates with Levy Disorder: Anomalous Localization and Exchange Broadening of Optical Spectra", Phys. Rev. Lett. 109, 259701 (https://arxiv.org/abs/1208.2779)Jun 06 2016The Comment to the Letter "Excitons in Molecular Aggregates with Levy Disorder: Anomalous Localization and Exchange Broadening of Optical Spectra" appeared in Phys. Rev. Lett. 109, 259701 (submitted on November 28, 2011). I prepared the below response ... More
Supplemental Material for Comment on "Excitons in Molecular Aggregates with Levy Disorder: Anomalous Localization and Exchange Broadening of Optical Spectra", Phys.Rev.Lett. 109, 259701 (https://arxiv.org/abs/1208.2779)Jun 02 2016In their Letter "Excitons in Molecular Aggregates with Levy Disorder: Anomalous Localization and Exchange Broadening of Optical Spectra", Eisfeld et al. predicted the existence of exchange broadening and blue-shift of the absorption band and a non-universal ... More
Diffractive asymmetry of electroweak vector bosons at the LHCNov 04 2009Nov 24 2009We analyse diffractive weak boson production in $pp$ collisions. We show that the measurement of $W$ boson production asymmetry in the diffractive $pp$ collisions is a valuable method to test the concept of the flavour symmetric pomeron parton distributions. ... More
Attraction to natural stimuli in Drosophila melanogasterJul 16 2009The animals, in particular insects (Drosophila melanogaster), response towards odor stimuli in nature can be established by measuring the dynamic of the odor response. Such an approach is innovative since responses to odors were tested only at certain ... More
Complete Decompositions of Coxeter groups orbit products of $A_2, C_2, G_2$ and $H_2$ and some limits for themApr 18 2013Feb 17 2014Orbits of the Weyl reflection groups attached to the simple Lie groups $A_2, C_2, G_2$ and Coxeter group $H_2$ are considered. For each of the groups products of any two orbits are decomposed into the union of the orbits. Results are presented in a single ... More
Optimal upper bounds on expected kth record values from IGFR distributionsFeb 04 2019The paper concerns the optimal upper bounds on the expectations of the kth record values (k >= 1) centered about the sample mean. We consider the case, when the records are based on the infinite sequence of the independent identically distributed random ... More
Status of PhokharaDec 10 2008A review of the status of the Monte Carlo event generator PHOKHARA, developed for experiments using the radiative return method. The four-pion production in electron-positron annihilation and in tau-lepton decays and the narrow resonances studies are ... More
Continuum-limit scaling of overlap fermions as valence quarksOct 05 2009We present the results of a mixed action approach, employing dynamical twisted mass fermions in the sea sector and overlap valence fermions, with the aim of testing the continuum limit scaling behaviour of physical quantities, taking the pion decay constant ... More
Twisted mass Dirac spectrumDec 05 2016The microscopic spectral density for lattice QCD with $N_f = 2+1+1$ twisted mass fermions is computed numerically and compared to analytical predictions of Wilson $\chi$-PT at a fixed index. In this way, we obtain results for the chiral condensate and ... More
Continuum limit of the $D$ meson, $D_s$ meson and charmonium spectrum from $N_f=2+1+1$ twisted mass lattice QCDMar 21 2016Nov 22 2016We compute masses of $D$ meson, $D_s$ meson and charmonium states using $N_f=2+1+1$ Wilson twisted mass lattice QCD. All results are extrapolated to physical light quark masses, physical strange and charm quark masses and to the continuum. Our analysis ... More
Short distance singularities and automatic O($a$) improvement: the cases of the chiral condensate and the topological susceptibilityDec 01 2014Apr 13 2015Short-distance singularities in lattice correlators can modify their Symanzik expansion by leading to additional O($a$) lattice artifacts. At the example of the chiral condensate and the topological susceptibility, we show how to account for these lattice ... More
Continuum Limit of Overlap Valence Quarks on a Twisted Mass SeaDec 20 2010We study a lattice QCD mixed action with overlap valence quarks on two flavours of Wilson maximally twisted mass sea quarks. Employing three different matching conditions to relate both actions to each other, we investigate the continuum limit by using ... More
Non-perturbative running of renormalization constants from correlators in coordinate space using step scalingAug 08 2016Working in a quenched setup with Wilson twisted mass valence fermions, we explore the possibility to compute non-perturbatively the step scaling function using the coordinate (X-space) renormalization scheme. This scheme has the advantage of being on-shell ... More
The continuum limit of the $D$ meson, $D_s$ meson and charmonium spectrum from $N_f=2+1+1$ twisted mass lattice QCDMar 21 2016We compute masses of $D$ meson, $D_s$ meson and charmonium states using $N_f=2+1+1$ Wilson twisted mass lattice QCD. All results are extrapolated to physical light quark masses, physical strange and charm quark masses and to the continuum. Our analysis ... More
Time delays between the soft and hard X-ray bands in GRS 1915+105Sep 28 2004The hard X-ray lightcurves exhibit delays of $\sim 1$ s with respect to the soft X-ray lightcurves when the microquasar GRS 1915+105 is in the state of frequent, regular outbursts (states $\rho$ and $\kappa$ of Belloni et al. 2000). Such outbursts are ... More
Thermal and Viscous Instability of Accretion Disc in AGNAug 23 2000The standard accretion discs are known to be thermally and viscously unstable over a certain range of temperatures. In the inner disc regions there may develop radiation pressure driven instability, which is possibly related to the rapid variability detected ... More
Hadronic cross section from radiative returnFeb 03 2004The impact of final-state radiation (FSR) on the radiative return method for the extraction of the e+e- hadronic cross section is discussed in detail and experimental tests of the model dependence of FSR are proposed for the pi+pi- hadronic final state. ... More
Dipole model analysis of high precision HERA dataDec 14 2013We analyse, within a dipole model, the inclusive DIS cross section data, obtained from the combination of the H1 and ZEUS HERA measurements. We show that these high precision data are very well described within the dipole model framework, which is complemented ... More
Numerical test of the method for revealing traces of deterministic chaos in the accreting black holesApr 10 2016The high energy radiation emitted by black hole X-ray binaries originates in an accretion disk, hence the variability of the lightcurves mirrors the dynamics of the disc. We study the time evolution of the emitted flux in order to find evidences, that ... More
Oscillating shocks in the low angular momentum flows as a source of variability of accreting black holesNov 28 2014We derive the conditions for shock formation in a quasi-spherical, slightly rotating flows. We verify the results of semi-analytical, stationary calculations with the time evolution studied by numerical hydro-simulations, and we study the oscillations ... More
Flops and spherical functorsNov 02 2015We study the derived categories of varieties X and X^+ connected by a flop. We assume that flopping contractions f: X\to Y, f^+: X^+ \to Y have fibers of relative dimension bounded by one and Y has canonical hypersurface singularities of multiplicity ... More
FSR at leading and next-to-leading order in the radiative return at meson factoriesOct 30 2003The impact of final-state radiation (FSR) on the radiative return method for the extraction of the e+e- hadronic cross section is discussed in detail. Possible experimental tests of the model dependence of FSR are proposed for the pi+pi- hadronic final ... More
On immanant functions related to Weyl groups of $A_n$Dec 04 2014In this work we recall the definition of matrix immanants, a generalization of the determinant and permanent of a matrix. We use them to generalize families of symmetric and antisymmetric orbit functions related to Weyl groups of the simple Lie algebras ... More
Anomalous diffusion models: different types of subordinator distributionOct 13 2011Subordinated processes play an important role in modeling anomalous diffusion-type behavior. In such models the observed constant time periods are described by the subordinator distribution. Therefore, on the basis of the observed time series, it is possible ... More
Non-linear behaviour of XTE J1550-564 during its 1998-1999 outburst, revealed by recurrence analysisMay 19 2016We study the X-ray emission of the microquasar XTE J1550-564 and analyze the properties of its light curves using the recurrence analysis method. The indicators for non-linear dynamics of the accretion flow are found in the very high state and soft state ... More
Topological expansion of the coefficients of zonal polynomials in genus oneAug 16 2011We use a combinatorial interpretation of the coefficients of zonal Kerov polynomials as a number of unoriented maps to derive an explicit formula for the coefficients in genus one.
The Ramsey number for a triple of large cyclesSep 01 2007We find the asymptotic value of the Ramsey number for a triple of long cycles, where the lengths of the cycles are large but may have different parity.
Simulations of coalescing black holesFeb 16 2016May 19 2016We describe the methods and results of numerical simulations of coalescing black holes. The simulation in dynamical spacetime covers the inspiral, merger, and ringdown phases. We analyze the emission of gravitational waves and properties of a black hole ... More
Gamma Ray Bursts. Progenitors, accretion in the central engine, jet acceleration mechanismsMar 21 2018May 09 2018The collapsar model was proposed to explain the long-duration gamma-ray bursts (GRBs), while the short GRBs are associated with the mergers of compact objects. In the first case, mainly the energetics of the events is consistent with the proposed progenitor ... More
On some nonlinear extensions of the Gagliardo-Nirenberg inequality with applications to nonlinear eigenvalue problemsApr 11 2011We derive inequality [\int_{\r} |f^{'}(x)|^ph(f(x))dx \le (\sqrt{p-1})^p\int_{\r}(\sqrt{|f^{"}(x){\cal T}_h(f(x))|})^ph(f(x))dx,] where $f$ belongs locally to Sobolev space $W^{2,1}$ and $f^{'}$ has bounded support. Here $h(...)$ is a given function and ... More
Self-Regulation in Infinite Populations with Fission-Death DynamicsJul 11 2018The evolution of an infinite population of interacting point entities placed in $\mathbb{R}^d$ is studied. The elementary evolutionary acts are death of an entity with rate that includes a competition term and independent fission into two entities. The ... More
Evolution of states of an infinite fission-death systemApr 04 2018The evolution of an infinite system of interacting point entities with traits $x\in \mathds{R}^d$ is studied. The elementary acts of the evolution are state-dependent death of an entity with rate that includes a competition term and independent fission ... More
Remark on atomic decompositions for Hardy space $H^1$ in the rational Dunkl settingMar 27 2018May 13 2018Let $\Delta$ be the Dunkl Laplacian on $\mathbb R^N$ associated with a normalized root system $R$ and a multiplicity function $k(\alpha)\geq 0$. We say that a function $f$ belongs to the Hardy space $H^1_{\Delta}$ if the nontangential maximal function ... More
Computing the topological susceptibility from fixed topology QCD simulationsMay 27 2016The topological susceptibility is an important quantity in QCD, which can be computed using lattice methods. However, at a fine lattice spacing, or when using high quality chirally symmetric quarks, algorithms which proceed in small update steps --- in ... More
Dipole model analysis of highest precision HERA data, including very low $Q^2$'sNov 30 2016We analyse, within a dipole model, the final, inclusive HERA DIS cross section data in the low $x$ region, using fully correlated errors. We show, that these highest precision data are very well described within the dipole model framework starting from ... More
Properties of the two-temperature corona model for active galactic nuclei and galactic black holesDec 22 1999We study in detail the properties of the accreting corona model for active galactic nuclei and galactic black holes. In this model the fraction of the energy liberated in the corona at a given radius is calculated from the global parameters of the model ... More
Accretion and outflow from a magnetized, neutrino cooled torus in the gamma ray burst central engineNov 23 2011Gamma Ray Bursts (GRB) are the extremely energetic transient events, visible from the most distant parts of the Universe. They are most likely powered by accretion on the hyper-Eddington rates that proceeds onto a newly born stellar mass black hole. This ... More
On the homeomorphism groups of manifolds and their universal coveringsApr 12 2011Jun 07 2011Let $\mathcal H_c(M)$ stand for the path connected identity component of the group of all compactly supported homeomorphisms of a manifold $M$. It is shown that $\mathcal H_c(M)$ is perfect and simple under mild assumptions on $M$. Next, conjugation-invariant ... More
Theory of spin waves in ferromagnetic (Ga,Mn)AsJun 07 2010Oct 09 2010The collective behavior of spins in a dilute magnetic semiconductor is determined by their mutual interactions and influenced by the underlying crystal structure. Hence, we begin with the atomic quantum-mechanical description of this system using the ... More
Radiative return physics program within EURIDICE networkJul 09 2007Aug 08 2007A short review of both theoretical and experimental aspects of the radiative return method is presented with the emphasize on the results obtained within the EURIDICE network. It is shown that the method gives not only possibility of an independent from ... More
Is the a0(980) resonance a K anti-K bound state?Jul 15 2004We have analysed properties of two resonances a0(980) and a0(1450) using the pion-eta and K anti-K coupled channel model. Although the forces in the scalar-isovector K anti-K channel are attractive the a0(980) resonance cannot be interpreted as a kaon-antikaon ... More
On noncommutative isotropic harmonic oscillatorJul 28 2004Energy spectrum of isotropic oscillator as a function of noncommutativity parameter theta is studied. It is shown that for a dense set of values of theta the spectrum is degenerated and the algebra responsible for degeneracy can be always chosen to be ... More
Quaternion Gaussian matrices satisfy the RIPApr 28 2017We prove that quaternion Gaussian random matrices satisfy the restricted isometry property (RIP) with overwhelming probability. We also explain why the restricted isometry random variables (RIV) approach is not appropriate for drawing conclusions on restricted ... More
A note on $k$-cordial $p$-uniform hypertreesOct 13 2009Hovey introduced a $k$-cordial labeling of graphs as a generalization both of harmonious and cordial labelings. He proved that all tress are $k$-cordial for $k \in \{1,...,5\}$ and he conjectured that all trees are $k$-cordial for all $k$. \indent We ... More
Influence of a Brane Tension on Phantom and Massive Scalar Field EmissionMay 27 2009We elaborate the signature of the extra dimensions and brane tension in the process of phantom and massive scalar emission in the spacetime of (4+n)-dimensional tense brane black hole. Absorption cross section, luminosity of Hawking radiation and cross ... More
Some Properties of the Spin-Polarized Attractive Hubbard ModelSep 08 2008Feb 24 2009The influence of a Zeeman magnetic field on the superconducting characteristics of the attractive Hubbard model was investigated. The ground state and temperature phase diagrams were obtained for a fixed number of particles. Two critical magnetic fields ... More
Properties of the a0 resonancesSep 25 2002We present results following from the coupled channel model of two a0 resonances decaying into the pi-eta and K anti-K mesons. The a0(980) resonance can be described by two distinct poles. It is shown that the discrepancy in the a0(980) mass position ... More
Low angular momentum accretion in the collapsar: how long can a long GRB be?Aug 20 2007Nov 30 2007The collapsar model is the most promising scenario to explain the huge release of energy associated with long duration gamma-ray-bursts (GRBs). Within this scenario GRBs are believed to be powered by accretion through a rotationally support torus or by ... More
Network models of dissolution of porous mediaNov 07 2012We investigate the chemical dissolution of porous media using a network model in which the system is represented as a series of interconnected pipes with the diameter of each segment increasing in proportion to the local reactant consumption. Moreover, ... More
Nonlinear parabolic problems in Musielak--Orlicz spacesJun 10 2013Our studies are directed to the existence of weak solutions to a parabolic problem containing a multi-valued term. The problem is formulated in the language of maximal monotone graphs. We assume that the growth and coercivity conditions of a nonlinear ... More
Dipole model analysis of highest precision HERA data, including very low $Q^2$'sNov 30 2016Jan 10 2017We analyse, within a dipole model, the final, inclusive HERA DIS cross section data in the low $x$ region, using fully correlated errors. We show, that these highest precision data are very well described within the dipole model framework starting from ... More
Compressed sensing for real measurements of quaternion signalsMay 25 2016The article concerns compressed sensing methods in the quaternion algebra. We prove that it is possible to uniquely reconstruct - by $\ell_1$ norm minimization - a sparse quaternion signal from a limited number of its real linear measurements, provided ... More
New developments in PHOKHARA Monte Carlo generatorOct 23 2007The present status of the physics program, which led to the development of the Monte Carlo event generator PHOKHARA is described. The possibility of using the radiative return method in various aspects of hadronic physics, from the measurement of the ... More
Investigation of $B\bar B$ four-quark systems using lattice QCDFeb 24 2016Feb 29 2016We investigate $B \bar B$ systems by computing potentials of two static quarks in the presence of two quarks of finite mass using lattice QCD. By solving the Schr\"odinger equation we check whether these potentials are sufficiently attractive to host ... More
Exploring possibly existing $q q \bar b \bar b$ tetraquark states with $q q = ud, ss, cc$Aug 03 2015We compute potentials of two static antiquarks in the presence of two quarks $qq$ of finite mass using lattice QCD. In a second step we solve the Schr\"odinger equation, to determine, whether the resulting potentials are sufficiently attractive to host ... More
Gamma-rays as probes of the UniverseFeb 22 2016The propagation of $\gamma$ rays over very large distances provides new insights on the intergalactic medium and on fundamental physics. On their path to the Earth, $\gamma$ rays can annihilate with diffuse infrared or optical photons of the intergalactic ... More
A formulation of the fractional Noether-type theorem for multidimensional LagrangiansMar 09 2012This paper presents the Euler-Lagrange equations for fractional variational problems with multiple integrals. The fractional Noether-type theorem for conservative and nonconservative generalized physical systems is proved. Our approach uses well-known ... More
Fractional variational calculus for non-differentiable functions, chapterJan 31 2012The fractional calculus of variations is now a subject under strong research. Different definitions for fractional derivatives and integrals are used, depending on the purpose under study. In this paper the fractional operators are defined in the sense ... More
Resummation effects in Higgs boson transverse momentum distribution within the framework of unintegrated parton distributionsSep 26 2003The cross sections describing the transverse momentum distributions of Higgs bosons are discussed within the framework of unintegrated parton distributions obtained from the CCFM equations in the single loop approximation. It is shown how the approximate ... More
Heavy baryon massesAug 06 1996Aug 07 1996Simple and plausible rules are used to correlate the masses of the ground-state baryons containing single heavy ($b$ or $c$) quarks. A comparison with the experimental data shows that the observed mass difference between the $\Sigma_b$ and the $\Sigma^*_b$ ... More
PHOKHARA 7.0 Monte Carlo generator: the narrow resonances implementation and new pion and kaon form factorsJan 15 2011Experiments at high luminosity electron-positron colliders allow to study the kaon and the pion form factors in the time-like region up to high energies. Also the kaon and the pion pair production at and around the narrow resonances J/psi and psi(2S) ... More
Coupled channel study of a0 resonancesMar 27 2002Jun 11 2002The coupled channel model of the a0(980) and a0(1450) resonances has been constructed using the separable pion-eta and K-anti K interactions. We have shown that two S-matrix poles corresponding to the a0(980) meson have significantly different widths ... More
The Merging Path Plot: adaptive fusing of k-groups with likelihood-based model selectionSep 13 2017Dec 12 2017There are many statistical tests that verify the null hypothesis: the variable of interest has the same distribution among k-groups. But once the null hypothesis is rejected, how to present the structure of dissimilarity between groups? In this article, ... More
On different types of instabilities in black hole accretion discs. Implications for X-ray binaries and AGNFeb 16 2011We discuss two important instability mechanisms that may lead to the limit-cycle oscillations of the luminosity of the accretion disks around compact objects: ionization instability and radiation-pressure instability. Ionization instability is well established ... More
Stabilization of radiation pressure dominated accretion disks by viscous fluctuationsMar 01 2012The standard thin accretion disk model has been successfully used to explain the soft X-ray spectra of Galactic black hole systems and perhaps the UV emission of Active Galactic Nuclei. However, radiation pressure dominated disks are known to be viscously ... More
Nucleosynthesis of heavy elements in gamma ray burstsApr 01 2015The ultrarelativistic jets responsible for prompt and afterglow emission in gamma ray bursts are presumably driven by a central engine that consists of a dense accretion disk around a spinning black hole. We consider such engine, composed of free nucleons, ... More
Anisotropic parabolic problems with slowly or rapidly growing termsJul 09 2013Nov 26 2013We consider an abstract parabolic problem in a framework of maximal monotone graphs, possibly multi-valued with growth conditions formulated with help of an $x-$dependent $N-$function. The main novelty of the paper consists in the lack of any growth restrictions ... More
Kummer and gamma laws through independences on trees - another parallel with the Matsumoto-Yor propertyOct 31 2015Jul 14 2016The paper develops a rather unexpected parallel to the multivariate Matsumoto--Yor (MY) property on trees considered in \cite{MW04}. The parallel concerns a multivariate version of the Kummer distribution, which is generated by a tree. Given a tree of ... More
Independence characterization for Wishart and Kummer random matricesJun 29 2017May 15 2018We generalize the following univariate characterization of the Kummer and Gamma distributions to the cone of symmetric positive definite matrices: let $X$ and $Y$ be independent, non-degenerate random variables valued in $(0, \infty)$, then $U= Y/(1+X)$ ... More
On certain variant of strongly nonlinear interpolation inequality in dimension nNov 26 2016We obtain the inequality $$\int_{\Omega}|\nabla u(x)|^ph(u(x))dx\leq C(n,p)\int_{\Omega} \left( \sqrt{ |\nabla^{(2)} u(x)||{\cal T}_{h,C}(u(x))|}\right)^{p}h(u(x))dx,$$ where $\Omega\subseteq {\bf R}^n$ and $n\ge 2$, $u:\Omega\rightarrow {\bf R}$ is in ... More
On one variant of strongly nonlinear Gagliardo-Nirenberg inequality involving Laplace operator with application to nonlinear elliptic problemsNov 06 2018We obtain the inequality $$\int_{\Omega}|\nabla u(x)|^ph(u(x))dx\leq C(n,p)\int_{\Omega} \left( \sqrt{ |\Delta u(x)||{\cal T}_{h,C}(u(x))|}\right)^{p}h(u(x))dx,$$ where $\Omega\subset \mathbf{R}^n$ is a bounded Lipschitz domain, $u\in W^{2,1}_{loc}(\Omega)$ ... More
Hörmander's multiplier theorem for the Dunkl transformJul 07 2018For a normalized root system $R$ in $\mathbb R^N$ and a multiplicity function $k\geq 0$ let $\mathbf N=N+\sum_{\alpha \in R} k(\alpha)$. Denote by $dw(\mathbf x)=\prod_{\alpha\in R}|\langle \mathbf x,\alpha\rangle|^{k(\alpha)}\, d\mathbf x $ the associated ... More
Compressed sensing in the quaternion algebraApr 25 2017May 22 2017The article concerns compressed sensing methods in the quaternion algebra. We prove that it is possible to uniquely reconstruct - by $\ell_1$-norm minimization - a sparse quaternion signal from a limited number of its linear measurements, provided the ... More
Ringel duality as an instance of Koszul dualityJan 22 2017Dec 19 2017In their previous work, S. Koenig, S. Ovsienko and the second author showed that every quasi-hereditary algebra is Morita equivalent to the right algebra, i.e. the opposite algebra of the left dual, of a coring. Let $A$ be an associative algebra and $V$ ... More
Canonical tilting relative generatorsJan 30 2017Sep 18 2017Given a relatively projective birational morphism $f\colon X\to Y$ of smooth algebraic spaces with dimension of fibers bounded by 1, we construct tilting relative (over $Y$) generators $T_{X,f}$ and $S_{X,f}$ in $\mathcal{D}^b(X)$. We develop a piece ... More