Results for "Joanna Mikolajewska"

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Symbiotic Stars in the Magellanic CloudsFeb 24 2004Orbital periods and other parameters of symbiotic binaries in the LMC and SMC are presented and discussed. In particular, the symbiotic stars in the MCs are compared with those in the Milky Way.
Observed Properties of Mass Loss in Symbiotic BinariesJan 03 2000Both the red giants and the Mira variables in symbiotic systems have systematically higher mass-loss rates than do typical galactic giants and Miras, which suggests that only very evolved giants, and so those with highest mass-loss rates, can support ... More
Symbiotic NovaeNov 25 2010Mar 31 2011The symbiotic novae are thermonuclear novae in symbiotic binary systems -- interacting binaries with evolved red giant donors, and the longest orbital periods. This paper aims at presenting physical characteristics of these objects and discussing their ... More
The Place of Recurrent Novae among the Symbiotic StarsMar 26 2008The observational properties of recurrent novae indicate that they can be divided into two subclasses:systems with a dwarf and a red giant secondary, respectively. The second type -- which includes RS Oph -- bears many similarities to symbiotic stars. ... More
Orbital and stellar parameters of symbiotic starsOct 22 2002This paper reviews current knowledge of symbiotic binaries, with special emphasis on their multifrequency observational characteristics, and basic parameters of the symbiotic system components. We start with a brief presentation of variable phenomena ... More
Optical and Near-IR Monitoring of Symbiotic Binary SystemsMar 29 2001Symbiotic stars are long-period interacting binary systems in which an evolved red giant star transfers material to its much hotter compact companion. Such a composition places them among the most variable stars. In addition to periodic variations due ... More
Distinguishing between symbiotic stars and planetary nebulaeAug 17 2017Number of known symbiotic stars (SySt) is still significantly lower than their predicted population. One of the main problems in finding complete population of SySt is the fact that their spectrum can be confused with other objects, such as planetary ... More
The Massive CO White Dwarf in the Symbiotic Recurrent Nova RS OphiuchiFeb 28 2017Aug 15 2017If accreting white dwarfs (WD) in binary systems are to produce type Ia supernovae (SNIa), they must grow to nearly the Chandrasekhar mass and ignite carbon burning. Proving conclusively that a WD has grown substantially since its birth is a challenging ... More
Cyg X-3: a low-mass black hole or a neutron starAug 27 2012Nov 14 2012Cyg X-3 is a highly interesting accreting X-ray binary, emitting from the radio to high-energy gamma-rays. It consists of a compact object wind-fed by a Wolf-Rayet (WR) star, but the masses of the components and the mass-loss rate have been a subject ... More
Variability of the symbiotic X-ray binary GX 1+4: Enhanced activity near periastron passageFeb 22 2017Context. GX 1+4 belongs to a rare class of X-ray binaries with red giant donors, symbiotic X-ray binaries. The system has a history of complicated variability on multiple timescales in the optical light and X-rays. The nature of this variability remains ... More
An X-Ray and Optical Light Curv Model of the Eclipsing Symbiotic Binary SMC3Nov 25 2012Some binary evolution scenarios to Type Ia supernovae include long-period binaries that evolve to symbiotic supersoft X-ray sources in their late stage of evolution. However, symbiotic stars with steady hydrogen burning on the white dwarf's (WD) surface ... More
On the resolved radio emission from AG Draconis: evidence for jet ejection?Jun 27 2002The recent detection of resolved radio emission from AG Dra by MERLIN reported by Ogley et al. is discussed in the context of the wind environment and the physical parameters and geometry of this symbiotic binary system. In particular, it is shown that ... More
Chemical abundance analysis of symbiotic giants - II. AE Ara, BX Mon, KX TrA, and CL ScoOct 10 2014Dec 02 2014Knowledge of the elemental abundances of symbiotic giants is essential to address the role of chemical composition in the evolution of symbiotic binaries, to map their parent population, and to trace their mass transfer history. However, there are few ... More
First detection and characterization of symbiotic stars in M31Jun 11 2014Jul 22 2014Symbiotic binaries are putative progenitors of type Ia supernovae. The census of Galactic symbiotic binaries is so incomplete that we cannot reliably estimate the total population of these stars, and use it to check whether that number is consistent with ... More
Evolution of the Symbiotic Nova PU Vul -- Outbursting White Dwarf, Nebulae, and Pulsating Red Giant CompanionFeb 28 2012We present a composite light-curve model of the symbiotic nova PU Vul (Nova Vulpeculae 1979) that shows a long-lasted flat optical peak followed by a slow decline. Our model light-curve consists of three components of emission, i.e., an outbursting white ... More
Probing the Accreting Hot Components in Six S-Type Symbiotic VariablesNov 23 2015We have carried out a spectroscopic analysis of the far ultraviolet spectra of six symbiotic variables. Two systems, LT Del, which has had one recorded outburst, and BD-21 3873 (= IV Vir) which has had no recorded outburst, are yellow symbiotic systems. ... More
Chemical abundance analysis of symbiotic giants - III. Metallicity and CNO abundance patterns in 24 southern systemsDec 24 2014Nov 13 2015The elemental abundances of symbiotic giants are essential to address the role of chemical composition in the evolution of symbiotic binaries, to map their parent population, and to trace their mass transfer history. However, the number of symbiotic giants ... More
The first near infrared detection of XTE J1118+480 in quiescenceMay 26 2005We report the first quiescent detection of KV UMa, the optical counterpart of XTE J1118+480 at near infrared. The observed magnitudes and colours are consistent with a K7-M0 V star, at the distance 1.4 +/- 0.2 kpc. The light curve shows strong orbital ... More
Probing the Accreting Hot Components in Six S-Type Symbiotic VariablesNov 23 2015Mar 03 2017We have carried out a spectroscopic analysis of the far ultraviolet spectra of six symbiotic variables. Two systems, LT Del, which has had one recorded outburst, and BD-21 3873 (= IV Vir) which has had no recorded outburst, are yellow symbiotic systems. ... More
Active phases and flickering of a symbiotic recurrent nova T CrBJul 22 2016T CrB is a symbiotic recurrent nova known to exhibit active phases, characterised by apparent increases in the hot component temperature and the appearance of flickering, i.e. changes in the observed flux on the time-scale of minutes. Historical UV observations ... More
A D'-type symbiotic binary in the planetary nebula SMP LMC 88Feb 08 2018SMP LMC 88 is one of the planetary nebulae (PN) in the Large Magellanic Cloud. We identify in its spectrum Raman scattered O VI lines at 6825 and 7083A. This unambiguously classifies the central object of the nebula as a symbiotic star (SySt). We identified ... More
Chemical abundance analysis of 13 southern symbiotic giants from high-resolution spectra at ~1.56 μmDec 14 2016Jan 03 2017Symbiotic stars (SySt) are binaries composed of a star in the later stages of evolution and a stellar remnant. The enhanced mass-loss from the giant drives interacting mass exchange and makes these systems laboratories for understanding binary evolution. ... More
FUSE Spectroscopic Analysis of the Slowest Symbiotic Nova AG Peg During QuiescenceFeb 26 2019We present a far ultraviolet spectroscopic analysis of the slowest known symbiotic nova AG Peg (M3/4III giant + hot white dwarf; P = 818.4 days) which underwent a nova explosion in 1850 followed by a very slow decline that did not end until 1996, marking ... More
Characterization of the Most Luminous Star in M33: A Super Symbiotic BinaryDec 18 2014Jan 05 2015We present the first spectrum of the most luminous infrared star in M33, and use it to demonstrate that the object is almost certainly a binary composed of a massive O star and a dust-enshrouded Red Hypergiant. This is the most luminous symbiotic binary ... More
First spatial resolution of the stellar components of the interacting binary CH CygniOct 27 2009Dec 13 2009We report the first resolved bispectrum speckle interferometry of the symbiotic binary CH Cyg. The measured component separation, $\rho=42 \pm 2$ mas, is consistent with the one derived from the known spectroscopic orbit and distance. In particular, our ... More
FUSE Spectroscopy of the Accreting Hot Components in Symbiotic VariablesFeb 23 2017We have conducted a spectroscopic analysis of the far ultraviolet archival spectra of four symbiotic variables, EG And, AE Ara, CQ Dra and RW Hya. RW Hya and EG And have never had a recorded outburst while CQ Dra and AE Ara have outburst histories. We ... More
Wind Roche Lobe Overflow as a way to make type Ia supernova from the widest symbiotic systemsDec 06 2018Symbiotic stars are interacting binaries with one of the longest orbital periods. Since they can contain a massive white dwarf with a high accretion rate they are considered a possible type Ia supernovae (SNe Ia) progenitors. Among symbiotic binaries ... More
New binary parameters for the symbiotic recurrent nova T Coronae BorealisNov 13 1997Apr 19 1998The amplitude of the ellipsoidal variability, the mass function, and the evolutionary limits on the component masses have been used to constrain the binary system parameters. Contrary to all previous studies, our analysis shows that the mass ratio of ... More
The spectroscopic orbit and the geometry of R AqrApr 25 2008Jan 14 2009R Aqr is one of the closest symbiotic binaries and the only D-type system with radial velocity data suitable for orbital parameters estimation. The aims of our study are to derive a reliable spectroscopic orbit of the Mira component, and to establish ... More
On the radio spectrum of CI Cygni: a test of popular models for symbiotic starsJan 30 2001We have determined the spectral energy distribution at wavelengths between 6 cm and 0.85 mm for the proto-typical S(stellar)-type symbiotic star, CI Cygni, during quiescence. Data were obtained simultaneously with the Very Large Array and the SCUBA sub-millimetre ... More
Recurrent Novae at Quiescence: Systems with Giant SecondariesDec 23 1998Spectroscopic and photometric behaviour of the class of recurrent novae with giant secondaries (T Coronae Borealis, RS Ophiuchi, V3890 Sagittarii and V745 Scorpii) at quiescence are presented in this study. The hot component in these systems is variable, ... More
Chemical abundance analysis of symbiotic giants. RW Hya, SY Mus, BX Mon, and AE AraFeb 21 2014Symbiotic stars are the long period, binary systems of strongly interacting stars at the final stages of evolution which can be useful tool to understand the chemical evolution of the Galaxy and the formation of stellar populations. Knowledge of the chemical ... More
A Survey of the Local Group of Galaxies for Symbiotic Binary Stars. I. First detection of symbiotic stars in M33Aug 17 2016We present and discuss initial selection criteria and first results in M33 from a systematic search for extragalactic symbiotic stars. We show that the presence of diffuse interstellar gas emission can significantly contaminate the spectra of symbiotic ... More
The first transition Wolf-Rayet WN/C star in M31Oct 12 2015Three decades of searches have revealed 154 Wolf-Rayet (WR) stars in M31, with 62 of WC type, 92 of WN type and zero of transition type WN/C or WC/N. In apparent contrast, about two percent of the WR stars in the Galaxy, the LMC and M33 simultaneously ... More
LMC S63: a historical reappraisal of the outburst behaviour of a deeply eclipsing Magellanic symbiotic starMay 28 2015We present an analysis of multi-epoch low-resolution spectrophotometry, complemented by the light curves provided by massive photometric surveys spanning over 100 years, of the symbiotic binary LMC S63. We showed that it is an eclipsing binary with the ... More
The symbiotic binary system RX Puppis: a possible recurrent nova with a Mira companionJan 05 1999We present an analysis of photometric and spectroscopic observations of the symbiotic binary system RX Pup with the aims of developing a reliable binary for the system and identifying mechanisms responsible for its spectacular activity. The binary is ... More
SMC3 as a test to the binary evolutionDec 11 2015SMC 3 is one of the most interesting symbiotic stars. This binary contains a bright K-type giant transferring mass to a massive white dwarf comanion, which makes it is a very promising SN Ia candidate. We discuss the evolutionary status of the system ... More
Cyg X-3: a Galactic double black hole or black hole-neutron star progenitorSep 12 2012There are no known double black hole (BH-BH) or black hole-neutron star (BH-NS) systems. We argue that Cyg X-3 is a very likely BH-BH or BH-NS progenitor. This Galactic X-ray binary consists of a compact object, wind-fed by a Wolf-Rayet (WR) type companion. ... More
GRS 1915+105: the distance, radiative processes and energy-dependent variabilityApr 01 2005We present an exhaustive analysis of five broad-band observations of GRS 1915+105 in two variability states, chi and omega, observed simultaneously by the PCA, HEXTE and OSSE. We find all the spectra well fitted by Comptonization of disc blackbody photons, ... More
A deep survey for symbiotic stars in the Magellanic Clouds - 1. Methodology and first discoveries in the SMCNov 16 2018We have initiated a survey aimed at locating a nearly complete sample of classical symbiotic stars (SySt) in the Magellanic Clouds. Such a sample is nearly impossible to obtain in the Milky Way, and is essential to constrain the formation, evolution and ... More
Light curves of symbiotic stars in massive photomeric surveys II: S and D'-type systemsDec 20 2013Dec 27 2013We present results of period analysis of ASAS, MACHO and OGLE light curves of 79 symbiotic stars classified as S and D'-type. The light curves of 58 objects show variations with the orbital period. In case of 34 objects, orbital periods are estimated ... More
HII regions in symbiotic binaries and their radio emissionOct 31 2002The slow and dense wind from a symbiotic red giant can be significantly deflected toward the orbital plane by the gravitational pull of the companion star. In such an environment, the ionizing radiation from the companion creates a highly asymmetric HII ... More
Broad-band X-ray/gamma-ray spectra and binary parameters of GX 339-4 and their astrophysical implicationsJul 29 1998We present X-ray/gamma-ray spectra of the binary GX 339-4 observed in the hard state simultaneously by Ginga and CGRO OSSE during an outburst in 1991 September. The Ginga spectra are well represented by a power law with a photon spectral index of 1.75 ... More
LMC S154: the first Magellanic symbiotic recurrent novaFeb 07 2019Classical nova outburst has been suggested for a number of extragalactic symbiotic stars, but in none of the systems has it been proven. In this work we study the nature of one of these systems, LMC S154. We gathered archival photometric observations ... More
Champagne subregions of the unit discJan 07 2011Jun 20 2011This paper concerns harmonic measure on the domains that arise when infinitely many disjoint closed discs are removed from the unit disc. It investigates which configurations of discs are unavoidable for Brownian motion, and obtains refinements of related ... More
Isometric uniqueness of a complementably universal Banach space for Schauder decompositionsNov 09 2012Jun 10 2013We present an isometric version of the complementably universal Banach space $\mathbb{P}$ with a Schauder decomposition. The space $\mathbb{P}$ is isomorphic to Pe{\l}czy\'nski's space with a universal basis as well as to Kadec' complementably universal ... More
On basic curvature identities for almost (para)contact metric manifoldsSep 21 2012In monograph of D. E. Blair "Riemannian geometry of contact and symplectic manifolds" and in the paper of S. Zamkovoy "Canonical connections on paracontact manifolds", the curvature identities respectively for contact and paracontact metric manifold are ... More
Para-CR Structures on almost Paracontact Metric ManifoldsFeb 28 2012Apr 01 2012Almost paracontact metric manifolds are the famous examples of almost para-CR manifolds. We find necessary and suffcient conditions for such manifolds to be para-CR. Next we examine these conditions in certain subclasses of almost paracontact metric manifolds. ... More
A plactic algebra action on bosonic particle configurations: The classical caseJan 03 2019We study the plactic algebra and its action on bosonic particle configurations in the classical case. These particle configurations together with the action of the plactic generators can be identified with crystals of the quantum analogue of the symmetric ... More
Conformal mechanicsNov 19 2012Jan 08 2013The SL(2,R) invariant Hamiltonian systems are discussed within the frame- work of the orbit method. It is shown that both dynamics and symmetry trans- formations are globally well-defined on phase space. The flexibility in the choice of time variable ... More
The asymptotic strong Feller property does not imply the e-property for Markov-Feller semigroupsAug 22 2013T. Szarek [Stud. Math. 189 (2008), {\S} 4] have discussed the relationship between two important notions concerning Markov semigroups: the asymptotic strong Feller property and the e-property, asserting that the former property implies the latter one. ... More
Line formation regions of the UV spectrum of CI CygniSep 05 2006We have examined radial velocities and fluxes of ultraviolet emission lines at different epochs, deduced from archival IUE and GRHS/HST spectra. The line fluxes give electron densities and were in addition used to calculate emission measures, suggesting ... More
Mm/submm observations of symbiotic binary stars: implications for the mass loss and mass exchangeFeb 12 2001We discuss mm/submm spectra of a sample of symbiotic binary systems, and compare them with popular models proposed to account for their radio emission. We find that radio emission from quiescent S-type systems originates from a conical region of the red ... More
Mm/submm observations of symbiotic binary starsOct 22 2002We present and discuss mm/submm observations of quiescent S-type symbiotic systems, and compare them with popular models proposed to account for their radio emission. We find that the M giant mass-loss rates derived from our observations are systematically ... More
GX 339-4: the distance, state transitions, hysteresis and spectral correlationsFeb 16 2004Mar 12 2004We study X-ray and variability and distance of GX 339-4. We derive d>7 kpc, based on recent determination of the binary parameters. We study data from the Ginga/ASM, the CGRO/BATSE, and the RXTE/ASM, PCA and HEXTE. From 1987 to 2004, GX 339-4 underwent ... More
UV Emission line shifts of symbiotic binariesJan 02 2010Relative and absolute emission line shifts have been previously found for symbiotic binaries, but their cause was not clear. This work aims to better understand the emission line shifts. Positions of strong emission lines were measured on archival UV ... More
Nature of light variations in the symbiotic binary V417 CenNov 24 2010V417 Cen is a D'-type symbiotic system surrounded by a faint, extended asymmetric nebula. Optical photometric observations of this object cover last 20 years. They show strong long term modulation with a period of about 1700 days and amplitude about 1.5 ... More
The spectroscopic orbits and the geometrical configuration of the symbiotic binary AR PavonisMar 18 2002We analyze optical and near infrared spectra of intermediate and high resolution of the eclipsing symbiotic system AR Pavonis. We have obtained the radial velocity curves for the red and the hot component from the M-giant absorption lines and from the ... More
On the nature of the cool component of MWC 560Nov 27 2006MWC 560 (V694 Mon) is one of the most enigmatic symbiotic system with a very active accretion-powered hot component. Such activity can be supported only by a luminous asymptotic giant branch star, i.e. a Mira or SR variable, with a high mass-loss rate. ... More
Restricted size Ramsey number for $P_3$ versus cyclesJun 25 2017Nov 20 2018Let $F$, $G$ and $H$ be simple graphs. We say $F \rightarrow (G, H)$ if for every $2$-coloring of the edges of $F$ there exists a monochromatic $G$ or $H$ in $F$. The Ramsey number $r(G, H)$ is defined as $r(G, H) = min\{|V (F)|: F \rightarrow (G, H)\}$, ... More
Locally triangular graphs and normal quotients of the $n$-cubeJul 06 2015For an integer $n\geq 2$, the triangular graph has vertex set the $2$-subsets of $\{1,\ldots,n\}$ and edge set the pairs of $2$-subsets intersecting at one point. Such graphs are known to be halved graphs of bipartite rectagraphs, which are connected ... More
Free Jump Dynamics in ContinuumAug 27 2014The evolution is described of an infinite system of hopping point particles in $\mathbb{R}^d$. The states of the system are probability measures on the space of configurations of particles. Under the condition that the initial state $\mu_0$ has correlation ... More
Asymmetric truncated Toeplitz operators equal to the zero operatorSep 13 2016Asymmetric truncated Toeplitz operators are compressions of multiplication operators acting between two model spaces. These operators are natural generalizations of truncated Toeplitz operators. In this paper we describe symbols of asymmetric truncated ... More
Mesoscopic density grains in the 1d interacting Bose gas from the exact Yang-Yang solutionJul 31 2017Number fluctuations in a one-dimensional Bose gas consist of contributions from many smaller independent localized fluctuations, the density grains. We have derived a set of extended integral equations from the Yang-Yang solution for finite temperature ... More
Dynamical systems associated to the $β$-core in the repeated prisoner's dilemmaNov 29 2017We consider the repeated prisoner's dilemma (PD). We assume that players make their choices knowing only average payoffs from the previous stages. A player's strategy is a function from the convex hull $\mathfrak{S}$ of the set of payoffs into the set ... More
A hierarchy of maximal intersecting triple systemsAug 22 2016We reach beyond the celebrated theorems of Erd\H{o}s-Ko-Rado and Hilton-Milner, and, a recent theorem of Han-Kohayakawa, and determine all maximal intersecting triples systems. It turns out that for each $n\ge7$ there are exactly 15 pairwise non-isomorphic ... More
Accuracy of the lepton-nucleus scattering models in the quasielastic regionJun 21 2017We present a discussion of models of nuclear effects used to describe an inclusive electron-nucleus scattering in the quasielastic (QE) peak region, aiming to compare them and draw conclusion of their reliability when applied in neutrino-nucleus interactions. ... More
An isometrically universal Banach space with a monotone Schauder basisFeb 11 2014Mar 12 2014We present an isometric version of the complementably universal Banach space $\mathcal{B}$ with a monotone Schauder basis. The space $\mathcal{B}$ is isomorphic to Pe{\l}czy\'nski's space with a universal basis as well as to Kadec' complementably universal ... More
Remarks on Gurarii spacesNov 24 2011We present selected known results and some of their improvements, involving Gurarii spaces. A Banach space is Gurarii if it has certain natural extension property for almost isometric embeddings of finite-dimensional spaces. Deleting the word "almost", ... More
Slow-roll approximation in loop quantum cosmologyOct 12 2016The slow-roll approximation is an analytical approach to study dynamical properties of the inflationary universe. In this article, systematic construction of the slow-roll expansion for effective loop quantum cosmology is presented. The analysis is performed ... More
A Widom-Rowlinson Jump Dynamics in the ContinuumApr 26 2016We study the dynamics of an infinite system of point particles of two types. They perform random jumps in $\mathbf{R}^d$ in the course of which particles of different types repel each other whereas those of the same type do not interact. The states of ... More
Existence of global weak solutions for Navier-Stokes equations with large fluxSep 28 2010Global existence of weak solutions to the Navier-Stokes equation in a cylindrical domain under the slip boundary conditions and with inflow and outflow was proved. To prove the energy estimate, crucial for the proof, we use the Hopf function. This makes ... More
The high-energy gamma-ray detection of G73.9+0.9, a supernova remnant interacting with a molecular cloudSep 14 2015Sep 22 2015We have analysed the Fermi LAT data on the SNR G73.9+0.9. We have confirmed a previous detection of high-energy gamma-rays from this source at a high significance of $\simeq 12\sigma$. The observed spectrum shows a significant curvature, peaking in $E ... More
Synthetic Spectral Analysis of the Hot Component in the S-Type Symbiotic Variable EG AndromedaJul 26 2004We have applied grids of NLTE high gravity model atmospheres and optically thick accretion disk models for the first time to archival IUE and FUSE spectra of the S-type symbiotic variable EG And taken at superior spectroscopic conjunction when Rayleigh ... More
Light-curves of symbiotic stars in massive photometric surveys I: D-type systemsJun 22 2009ASAS, MACHO, OGLE and SAAO JHKL light curves of 13 stars, that have at some time been classified as D-type symbiotics, are analysed. Most of the near-IR light-curves that have been monitored over many years show long-term changes due to variable dust ... More
CO observations of symbiotic stellar systemsMar 16 2010We have performed mm-wave observations with the IRAM 30m telescope of the 12CO J=2-1 and J=1-0, 13CO J=2-1 and J=1-0, and SiO J=5-4 transitions in the symbiotic stars R Aqr, CH Cyg, and HM Sge. The data were analyzed by means of a simple analytical description ... More
An abundance analysis of the symbiotic star CH CygSep 28 2005The photospheric abundances for the cool component of the symbiotic star CH Cyg were calculated for the first time using high-resolution near-infrared spectra and the method of of standard LTE analysis and atmospheric models. The iron abundance for CH ... More
Dust evolution and satellitesimal formation in circumplanetary disksJul 07 2018Sep 11 2018It is believed that satellites of giant planets form in circumplanetary disks. Many of the previous contributions assumed that their formation process proceeds similarly to rocky planet formation, via accretion of the satellite seeds, called satellitesimals. ... More
Sharp and principal elements in effect algebrasApr 02 2015Jul 02 2015In this paper we characterize the effect algebras whose sharp and principal elements coincide. We also give examples of two non-isomorphic effect algebras having the same universum, partial order and orthosupplementation.
Paths in hypergraphs: a rescaling phenomenonJun 26 2017Let $P^k_\ell$ denote the loose $k$-path of length $\ell$ and let define $f^k_\ell(n,m)$ as the minimum value of $\Delta(H)$ over all $P^k_\ell$-free $k$-graphs $H$ with $n$ vertices and $m$ edges. In the paper we study the behavior of $f^4_2(n,m)$ and ... More
Goldie rank of primitive quotients via lattice point enumerationDec 21 2012Let k be an algebraically closed field of characteristic 0. Musson and vandenBergh classified primitive ideals for rings of torus invariant differential operators. This classification applies in particular to subquotients of localized extended Weyl algebras ... More
Smart Policies for Artificial IntelligenceAug 29 2016We argue that there already exists de facto artificial intelligence policy - a patchwork of policies impacting the field of AI's development in myriad ways. The key question related to AI policy, then, is not whether AI should be governed at all, but ... More
The Global Evolution of States of a Continuum Kawasaki Model with RepulsionMar 27 2016An infinite system of point particles performing random jumps in $\mathds{R}^d$ with repulsion is studied. The states of the system are probability measures on the space of particle's configurations. The result of the paper is the construction of the ... More
Exponential ergodicity of some Markov dynamical system with application to a Poisson driven stochastic differential equationJan 20 2018Feb 21 2018We are concerned with the asymptotics of the Markov chain given by the post-jump locations of a certain piecewise-deterministic Markov process with a state-dependent jump intensity. We provide sufficient conditions for such a model to possess a unique ... More
Everywhere divergence of the one-sided ergodic Hilbert transform and Liouville numbersJun 10 2016We prove some results on the behavior of infinite sums of the form $\Sigma f\circ T^n(x)\frac{1}{n}$, where $T:S^1\to S^1$ is an irrational circle rotation and $f$ is a mean-zero function on $S^1$. In particular, we show that for a certain class of functions ... More
A Hubble Space Telescope Survey for Novae in M87. I. Light and Color Curves, Spatial Distributions and the Nova RateFeb 02 2016Sep 01 2016The Hubble Space Telescope has imaged the central part of M87 over a 10 week span, leading to the discovery of 32 classical novae and nine fainter, likely very slow and/or symbiotic novae. In this first in a series of papers we present the M87 nova finder ... More
Modelling of lung cancer survival data for critical illness insurancesFeb 28 2016We derive a general multiple state model for critical illness insurances. In contrast to the classical model, we take into account that the probability of death for a dread disease sufferer may depend on the duration of the disease, and the payment of ... More
Periodic Longitude-Stationary Non-Drift Emission in Core-Single Radio Pulsar B1946+35Mar 29 2017Radio pulsar PSR B1946+35 is a classical example of a core/cone triple pulsar where the observer's line-of-sight cuts the emission beam centrally. In this paper we perform a detailed single-pulse polarimetric analysis of B1946+35 using sensitive Arecibo ... More
Ebola impact and quarantine in a network modelDec 20 2015Much effort has been directed towards using mathematical models to understand and predict contagious disease, in particular Ebola outbreaks. Classical SIR (susceptible-infected-recovered) compartmental models capture well the dynamics of the outbreak ... 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
On multicolor Ramsey number for 3-paths of length threeNov 24 2016We show that if we color the hyperedges of the complete $3$-uniform complete graph on $2n+\sqrt{18n+1}+2$ vertices with $n$ colors, then one of the color classes contains a loose path of length three.
The multipartite Ramsey number for the 3-path of length threeJun 27 2017We study the Ramsey number for the 3-path of length three and $n$ colors and show that $R(P^3_3;n)\le \lambda_0 n+7\sqrt{n}$, for some explicit constant $\lambda_0=1.97466\dots$.
Asymmetric truncated Toeplitz operators on finite-dimensional spacesNov 02 2016In this paper we consider asymmetric truncated Toeplitz operators acting between two finite-dimensional model spaces. We compute the dimension of the space of all such operators. We also describe the matrix representations of asymmetric truncated Toeplitz ... More
The base size of a primitive diagonal groupMay 09 2012A base B for a finite permutation group G acting on a set X is a subset of X with the property that only the identity of G can fix every point of B. We prove that a primitive diagonal group G has a base of size 2 unless the top group of G is the alternating ... More
Disjointness properties for Cartesian products of weakly mixing systemsDec 23 2011Jul 18 2012For $n\geq 1$ we consider the class JP($n$) of dynamical systems whose every ergodic joining with a Cartesian product of $k$ weakly mixing automorphisms ($k\geq n$) can be represented as the independent extension of a joining of the system with only $n$ ... More
Algebraic Properties of Valued Constraint Satisfaction ProblemMar 03 2014Apr 01 2015The paper presents an algebraic framework for optimization problems expressible as Valued Constraint Satisfaction Problems. Our results generalize the algebraic framework for the decision version (CSPs) provided by Bulatov et al. [SICOMP 2005]. We introduce ... More
Feedback and the fudamental line of low-luminosity LSB/dwarf galaxiesOct 20 2002Dec 12 2003We study in simple terms the role of feedback in establishing the scaling relations of low-surface-brightness and dwarf galaxies with stellar masses in the range 6x10^5 <M*< 3x10^10 Msun. These galaxies, as measured from SDSS and in the Local Group, show ... More
Finite homogeneous effect algebras with trivial sharp elementsSep 16 2016In this paper we describe finite homogeneous effect algebras whose sharp elements are only $0$ and $1$.
Premium valuation for a multiple state model containing manifold premium-paid statesJan 25 2017The aim of this contribution is to derive a general matrix formula for the net period premium paid in more than one state. For this purpose we propose to combine actuarial technics with the graph optimization methodology. The obtained result is useful ... More
On the Hausdorff dimension of invariant measures of weakly contracting on average measurable IFSJul 24 2007May 06 2008We consider measures which are invariant under a measurable iterated function system with positive, place-dependent probabilities in a separable metric space. We provide an upper bound of the Hausdorff dimension of such a measure if it is ergodic. We ... More