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Essential Spectrum of the Weighted Laplacian on Noncompact Manifolds and ApplicationsAug 04 2016We obtain upper estimates for the bottom (that is, greatest lower bound) of the essential spectrum of weighted Laplacian operator of a weighted manifold under assumptions of the volume growth of their geodesic balls and spheres. Furthermore, we find examples ... More

The $f$-Stability Index of the Constant Weighted Mean Curvature Hypersurfaces in Gradient Ricci SolitonsJan 02 2017In this paper, we prove that a noncompact complete hypersurface with finite weighted volume, weighted mean curvature vector bounded in norm, and isometrically immersed in a complete weighted manifold is proper. In addition, we obtain an estimate for $f$-stability ... More

It's a Trap: Emperor Palpatine's Poison PillNov 29 2015In this paper we study the financial repercussions of the destruction of two fully armed and operational moon-sized battle stations ("Death Stars") in a 4-year period and the dissolution of the galactic government in Star Wars. The emphasis of this work ... More

Exact Inflationary Solutions from a SuperpotentialMay 04 2000We propose a novel, potentially useful generating technique for constructing exact solutions of inflationary scalar field cosmologies with non-trivial potentials. The generating scheme uses the so-called superpotential and is inspired by recent studies ... More

Power-Law Inflation from the Rolling TachyonApr 17 2002Sep 09 2002Modeling the potential by an inverse square law in terms of the tachyon field ($V(T)=\beta T^{-2}$) we find exact solution for spatially flat isotropic universe.We show that for $\beta>2\sqrt{3}/3$ the model undergoes power-law inflation. A way to construct ... More

Character and Multiplicity Formulas for Compact Hamiltonian G-spacesNov 03 2014Let K $\subset$ G be compact connected Lie groups with common maximal torus T. Let (M, $\omega$) be a prequantisable compact connected symplectic manifold with a Hamiltonian G-action. Geometric quantisation gives a virtual representation of G; we give ... More

Co-word Maps and Topic Modeling: A Comparison Using Small and Medium-Sized Corpora (n < 1000)Nov 10 2015Feb 26 2016Induced by "big data," "topic modeling" has become an attractive alternative to mapping co-words in terms of co-occurrences and co-absences using network techniques. Does topic modeling provide an alternative for co-word mapping in research practices ... More

Moduli spaces of rank 3 parabolic bundles over a many-punctured surfaceMar 18 2019Let $M$ be the moduli space of rank 3 parabolic vector bundles over a Riemann surface with several punctures. By the Mehta-Seshadri correspondence, this is the space of rank 3 unitary representations of the fundamental group of the punctured surface with ... More

Self-Gravitating Bjorken FlowMar 27 2012I present a solution to the full Einstein-fluid equations representing a self-gravitating Bjorken flow. The motion and the geometry become inhomogeneous in the plane transversal to the flow and the energy density profile acquires, due to gravity, corrections ... More

Penrose Limits, the Colliding Plane Wave Problem and the Classical String BackgroundsJun 06 2002Sep 17 2002We show how the Szekeres form of the line element is naturally adapted to study Penrose limits in classical string backgrounds. Relating the "old" colliding wave problem to the Penrose limiting procedure as employed in string theory we discuss how two ... More

Financial Contagion and Asset Liquidation StrategiesJun 02 2015This paper provides a framework for modeling the financial system with multiple illiquid assets during a crisis. This extends the network model of Cifuentes, Shin & Ferrucci (2005) that incorporates a single asset with fire sales. We prove sufficient ... More

Formation of a Black String in a Higher Dimensional Vacuum Gravitational CollapseJun 12 2006Mar 31 2008We present a solution to the vacuum Einstein Equations which represents a collapse of a gravitational wave in 5 dimensions. Depending on the focal length of the wave, the collapse results, either in a black string covered by a horizon, or in a naked singularity ... More

Geometry of the intersection ring and vanishing relations in the cohomology of the moduli space of parabolic bundles on a curveFeb 02 2015Aug 03 2015We study the ring generated by the Chern classes of tautological line bundles on the moduli space of parabolic bundles of arbitrary rank on a Riemann surface. We show the Poincar\'e duals to these Chern classes have simple geometric representatives. We ... More

K2-136: A Hyades Binary Star with a Neptune-sized PlanetSep 29 2017Nov 06 2017We report the discovery of a Neptune-size planet (Rp = 3.0 Re) in the Hyades Cluster. The host star is in a binary system, comprising a K5V star and M7/8V star with a projected separation of 40 AU. The planet orbits the primary star with an orbital period ... More

Some aspects of pre big bang cosmologyJun 01 2001This is a summary of a course given at the Fourth Mexican School on Gravitation and Mathematical Physics on some aspects of PBB cosmology. After introductory remarks the lectures concentrate on some amusing consequences derived from the symmetries of ... More

Planetary Candidates from K2 Campaign 16Mar 12 2018May 23 2018Given that Campaign 16 of the K2 mission is one of just two K2 campaigns observed so far in "forward-facing" mode, which enables immediate follow-up observations from the ground, we present a catalog of interesting targets identified through photometry ... More

A proof of equivalence between level lines shortening and curvature motion in image processingFeb 07 2011Feb 06 2012In this paper we define the continuous Level Lines Shortening evolution of a two-dimensional image as the Curve Shortening operator acting simultaneously and independently on all the level lines of the initial data, and show that it computes a viscosity ... More

Relations in the cohomology ring of the moduli space of flat $SO(2n+1)$-connections on a Riemann surfaceJan 12 2018We consider the moduli space of flat $SO(2n+1)$-connections (up to gauge transformations) on a Riemann surface, with fixed holonomy around a marked point. There are natural line bundles over this moduli space; we construct geometric representatives for ... More

Multiportfolio time consistency for set-valued convex and coherent risk measuresDec 21 2012Oct 10 2014Equivalent characterizations of multiportfolio time consistency are deduced for closed convex and coherent set-valued risk measures on $L^p(\Omega,\mathcal F, P; R^d)$ with image space in the power set of $L^p(\Omega,\mathcal F_t,P;R^d)$. In the convex ... More

Partial regularity and t-analytic sets for Banach function algebrasDec 29 2014In this note we introduce the notion of $t$-analytic sets. Using this concept, we construct a class of closed prime ideals in Banach function algebras and discuss some problems related to Alling's conjecture in $H^\infty$. A description of all closed ... More

Optimization of Fire Sales and Borrowing in Systemic RiskFeb 12 2018Oct 01 2018This paper provides a framework for modeling financial contagion in a network subject to fire sales and price impacts, but allowing for firms to borrow to cover their shortfall as well. We consider both uncollateralized and collateralized loans. The main ... More

A Supermartingale Relation for Multivariate Risk MeasuresOct 19 2015May 25 2016The equivalence between multiportfolio time consistency of a dynamic multivariate risk measure and a supermartingale property is proven. Furthermore, the dual variables under which this set-valued supermartingale is a martingale are characterized as the ... More

The fingerprints of Photoionization and Shock-Ionization in two CSS sourcesOct 23 2015We investigate the ionization state of the Extended Emission-Line Regions (EELRs) around two compact steep-spectrum (CSS) radio galaxies, 3C~268.3 and 3C~303.1, in order to identify the contribution of photoionization and shock-ionization. We perform ... More

A counterexample to a conjecture of S.E. MorrisOct 13 2003We give a counterexample to a conjecture of S.E. Morris by showing that there is a compact plane set X such that R(X) has no non-zero, bounded point derivations but such that R(X) is not weakly amenable. We also give an example of a separable uniform ... More

Trapping Regions for the Navier-Stokes EquationsApr 18 2004Oct 27 2014In 1999, J.C. Mattingly and Ya. G. Sinai used elementary methods to prove the existence and uniqueness of smooth solutions to the 2D Navier-Stokes equations with periodic boundary conditions. And they were almost successful in proving the existence and ... More

Countable linear combinations of characters on commutative Banach algebrasDec 24 2014An elegant but elementary result of Wolff from 1921, when interpreted in terms of Banach algebras, shows that it is possible to find a sequence of distinct characters $\phi_n$ on the disc algebra and an $\ell_1$ sequence of complex numbers $\lambda_n$, ... More

K2-288Bb: A Small Temperate Planet in a Low-mass Binary System Discovered by Citizen ScientistsFeb 07 2019Observations from the Kepler and K2 missions have provided the astronomical community with unprecedented amounts of data to search for transiting exoplanets and other astrophysical phenomena. Here, we present K2-288, a low-mass binary system (M2.0 +/- ... More

Scanning Tunneling Spectroscopy of Graphene on GraphiteMar 28 2008Jun 11 2009We report low temperature high magnetic field scanning tunneling microscopy and spectroscopy of graphene flakes on graphite that exhibit the structural and electronic properties of graphene decoupled from the substrate. Pronounced peaks in the tunneling ... More

Heun functions and combinatorial identitiesJan 08 2018We give closed forms for several families of Heun functions related to classical entropies. By comparing two expressions of the same Heun function, we get several combinatorial identities generalizing some classical ones.

Do latent tree learning models identify meaningful structure in sentences?Sep 04 2017Feb 26 2018Recent work on the problem of latent tree learning has made it possible to train neural networks that learn to both parse a sentence and use the resulting parse to interpret the sentence, all without exposure to ground-truth parse trees at training time. ... More

Searching for evidence of jet-cloud interaction in radio galaxies. First results for 3C 381Jan 10 2013We present results of Gemini spectroscopy and Hubble Space Telescope imaging of the 3C~381 radio galaxy. Possible ionising mechanisms for the Extended Emission-Line Region were studied through state-of-the-art diagnostic analysis employing line-ratios. ... More

Strong Ditkin algebras without bounded relative unitsSep 09 1998Nov 13 1998In a previous note the author gave an example of a strong Ditkin algebra which does not have bounded relative units in the sense of Dales. In this note we investigate a certain family of Banach function algebras on the one point compactification of the ... More

A comparison of techniques for dynamic multivariate risk measuresMay 09 2013Jan 29 2015This paper contains an overview of results for dynamic multivariate risk measures. We provide the main results of four different approaches. We will prove under which assumptions results within these approaches coincide, and how properties like primal ... More

Dialogue Concerning The Two Chief World ViewsMay 26 2016In 1632, Galileo Galilei wrote a book called \textit{Dialogue Concerning the Two Chief World Systems} which compared the new Copernican model of the universe with the old Ptolemaic model. His book took the form of a dialogue between three philosophers, ... More

Ghosts in a MirrorApr 08 2003Apr 12 2003We look at some dynamic geometries produced by scalar fields with both the "right" and the "wrong" sign of the kinetic energy. We start with anisotropic homogeneous universes with closed, open and flat spatial sections. A non-singular solution to the ... More

Trivial Jensen measures without regularityDec 20 1999Dec 29 2014In this note we construct Swiss cheeses X such that R(X) is non-regular but such that R(X) has no non-trivial Jensen measures. We also construct a non-regular uniform algebra with compact, metrizable character space such that every point of the character ... More

Time consistency of dynamic risk measures in markets with transaction costsJan 06 2012Dec 21 2012The paper concerns primal and dual representations as well as time consistency of set-valued dynamic risk measures. Set-valued risk measures appear naturally when markets with transaction costs are considered and capital requirements can be made in a ... More

A Supermartingale Relation for Multivariate Risk MeasuresOct 19 2015Jan 31 2018The equivalence between multiportfolio time consistency of a dynamic multivariate risk measure and a supermartingale property is proven. Furthermore, the dual variables under which this set-valued supermartingale is a martingale are characterized as the ... More

Heun functions related to entropiesJan 08 2018We consider the indices of coincidence for the binomial, Poisson, and negative binomial distributions. They are related in a simple manner to the R\'{e}nyi entropy and Tsallis entropy. We investigate some families of Heun functions containing these indices ... More

Bounds for some entropies and special functionsJan 08 2018We consider a family of probability distributions depending on a real parameter and including the binomial, Poisson and negative binomial distributions. The corresponding index of coincidence satisfies a Heun differential equation and is a logarithmically ... More

The second-order analysis of marked spatio-temporal point processes, with an application to earthquake dataNov 15 2016To analyse interaction in marked spatio-temporal point processes (MSTPPs), we introduce marked (cross) second-order reduced moment measures and K-functions for general inhomogeneous second-order intensity reweighted stationary MSTPPs. These summary statistics, ... More

Shock-ionization in the Extended Emission-Line Region of 3C~305. The last piece of the (optical) puzzleJul 29 2013We present new Gemini spectroscopical data of the Extended Emission-Line Region of 3C~305 radio galaxy in order to achieve the final answer of the long-standing question about the ionizing mechanism. The spectra show strong kinematic disturbances within ... More

A Supermartingale Relation for Multivariate Risk MeasuresOct 19 2015Nov 15 2016The equivalence between multiportfolio time consistency of a dynamic multivariate risk measure and a supermartingale property is proven. Furthermore, the dual variables under which this set-valued supermartingale is a martingale are characterized as the ... More

Convergence from below sufficesDec 24 2014An elementary application of Fatou's lemma gives a strengthened version of the monotone convergence theorem. We call this the convergence from below theorem. We make the case that this result should be better known, and deserves a place in any introductory ... More

Morphisms of Berkovich curves and the different functionAug 13 2014Aug 31 2016Given a generically \'etale morphism $f\colon Y\to X$ of quasi-smooth Berkovich curves, we define a different function $\delta_f\colon Y\to[0,1]$ that measures the wildness of the topological ramification locus of $f$. This provides a new invariant for ... More

Quasianalyticity in certain Banach function algebrasMay 16 2016Let $X$ be a perfect, compact subset of the complex plane. We consider algebras of those functions on $X$ which satisfy a generalised notion of differentiability, which we call $\mathcal{F}$-differentiability. In particular, we investigate a notion of ... More

The Homogeneous Scalar Field and the Wet Dark Sides of the UniverseApr 07 2006Jul 13 2006We study the possibility that a generalised real scalar field minimally coupled to gravity could explain both the galactic and the cosmological dark components of the universe. Within the framework of Einstein's Relativity we model static galactic halos ... More

Compact homomorphisms between Dales-Davie algebrasNov 06 2003In this note we consider compact homomorphisms and endomorphisms between various Dales-Davie algebras. In particular, we obtain fairly complete results when the underlying set is the disc or the unit circle. Comparable results when the underlying set ... More

The Effects of Leverage Requirements and Fire Sales on Financial Contagion via Asset Liquidation Strategies in Financial NetworksJul 07 2015This paper provides a framework for modeling the financial system with multiple illiquid assets when liquidation of illiquid assets is caused by failure to meet a leverage requirement. This extends the network model of Cifuentes, Shin & Ferrucci (2005) ... More

Compact endomorphisms of H infinity of DOct 21 1998When G is a region in the complex plane, compact composition operators on the uniform algebra of bounded analytic functions on G and the spectra of these operators were described by D. Swanton, Compact composition operators on B(D), Proc. Amer. Math. ... More

Quasicompact endomorphisms of commutative semiprime Banach algebrasDec 29 2014This paper is a continuation of our study of compact, power compact, Riesz, and quasicompact endomorphisms of commutative Banach algebras. Previously it has been shown that if $B$ is a unital commutative semisimple Banach algebra with connected character ... More

Power-law expansion in k-essence cosmologyApr 30 2003Nov 10 2003We study spatially flat isotropic universes driven by k-essence. It is shown that Friedmann and k-field equations may be analytically integrated for arbitrary k-field potentials during evolution with a constant baryotropic index. It follows that there ... More

Endomorphisms of Banach algebras of infinitely differentiable functions on compact plane setsMay 20 1999In this note we study the endomorphisms of certain Banach algebras of infinitely differentiable functions on compact plane sets, associated with weight sequences M. These algebras were originally studied by Dales, Davie and McClure. In a previous paper ... More

Riesz endomorphisms of Banach algebrasMar 25 2004Let B be a unital commutative semi-simple Banach algebra. We study endomorphisms of B which are simultaneously Riesz operators. Clearly compact and power compact endomorphisms are Riesz. Several general theorems about Riesz endomorphisms are proved, and ... More

Compact endomorphisms of Banach algebras of infinitely differentiable functionsMay 02 2002Oct 12 2003We consider non-zero endomorphisms of the Dales and Davie algebras of infinitely differentiable functions on intervals in the real line. We discuss necessary and sufficient conditions for a selfmap of the interval to induce a compact endomorphism of these ... More

Nonreproducible connectome changes hint at functional heterogeneity of Parkinson's DiseaseNov 15 2016Since anatomic MRI is presently not able to directly discern neuronal loss in Parkinson's Disease (PD), studying the associated functional connectivity (FC) changes seems a promising approach toward developing non-invasive and non-radioactive neuroimaging ... More

On the Idiosyncrasies of the Mandarin Chinese Classifier SystemFeb 26 2019While idiosyncrasies of the Chinese classifier system have been a richly studied topic among linguists (Adams and Conklin, 1973; Erbaugh, 1986; Lakoff, 1986), not much work has been done to quantify them with statistical methods. In this paper, we introduce ... More

The Effects of Leverage Requirements and Fire Sales on Financial Contagion via Asset Liquidation Strategies in Financial NetworksJul 07 2015Oct 13 2016This paper provides a framework for modeling the financial system with multiple illiquid assets when liquidation of illiquid assets is caused by failure to meet a leverage requirement. This extends the network model of Cifuentes, Shin & Ferrucci (2005) ... More

Accelerating Universes from Short-Range InteractionsMay 20 2005Oct 11 2005We show that short-range interactions between the fundamental particles in the universe can drive a period of accelerated expansion. This description fits the early universe. In the present day universe, if one postulates short-range interactions or a ... More

Measures of Systemic RiskFeb 27 2015Mar 17 2016Systemic risk refers to the risk that the financial system is susceptible to failures due to the characteristics of the system itself. The tremendous cost of systemic risk requires the design and implementation of tools for the efficient macroprudential ... More

Banach function algebras with dense invertible groupNov 03 2004In an earlier paper, Dawson and the second author asked whether or not a Banach function algebra with dense invertible group can have a proper Shilov boundary. We give an example of a uniform algebra showing that this can happen, and investigate the properties ... More

Extensions of endomorphisms of C(X)Oct 01 2004For a compact space X we consider extending endomorphisms of the algebra C(X) to be endomorphisms of Arens-Hoffman and Cole extensions of C(X). Given a non-linear, monic polynomial p in C(X)[t], with C(X)[t]/pC(X)[t] semi-simple, we show that if an endomorphism ... More

The chain rule for $\mathcal F$-differentiationNov 30 2015Dec 10 2015Let $X$ be a perfect, compact subset of the complex plane, and let $D^{(1)}(X)$ denote the (complex) algebra of continuously complex-differentiable functions on $X$. Then $D^{(1)}(X)$ is a normed algebra of functions but, in some cases, fails to be a ... More

Suppression of charge density wave phases in ultrathin 1T-TaS2Jun 12 2015Using temperature dependent Raman spectroscopy we address the question of how the transition from bulk to few atomic layers affects the charge density wave (CDW) phases in 1T-TaS2. We find that for crystals with thickness larger than approx 10nm the transition ... More

Large Time Behavior of Periodic Viscosity Solutions for Uniformly Elliptic Integro-Differential EquationsOct 21 2012In this paper, we study the large time behavior of solutions of a class of parabolic fully nonlinear integro-differential equations in a periodic setting. In order to do so, we first solve the ergodic problem}(or cell problem), i.e. we construct solutions ... More

Lipschitz Regularity of Solutions for Mixed Integro-Differential EquationsJul 16 2011Jan 06 2012We establish new Hoelder and Lipschitz estimates for viscosity solutions of a large class of elliptic and parabolic nonlinear integro-differential equations, by the classical Ishii-Lions's method. We thus extend the Hoelder regularity results recently ... More

Automated Assignment of Backbone NMR Data using Artificial IntelligenceJun 18 2015Nuclear magnetic resonance (NMR) spectroscopy is a powerful method for the investigation of three-dimensional structures of biological molecules such as proteins. Determining a protein structure is essential for understanding its function and alterations ... More

Non-regularity for Banach function algebrasNov 10 1998Sep 21 1999Let $A$ be a unital Banach function algebra with character space $\Phi_A$. For $x\in \Phi_A$, let $M_x$ and $J_x$ be the ideals of functions vanishing at $x$, and in a neighbourhood of $x$, respectively. It is shown that the hull of $J_x$ is connected, ... More

Dynamic Clearing and Contagion in Financial NetworksJan 06 2018May 25 2018In this paper we will consider a generalized extension of the Eisenberg-Noe model of financial contagion to allow for time dynamics in both discrete and continuous time. Derivation and interpretation of the financial implications will be provided. Emphasis ... More

Can the Type-IIB axion prevent Pre-big Bang inflation?Jun 19 1998We look at the possibility of superinflationary behavior in a class of anisotropic Type-IIB superstring cosmologies in the context of Pre-big Bang scenario and find that there exists a rather narrow range of parameters for which these models inflate. ... More

The Origin of the Entropy in the UniverseOct 15 1996Mar 13 1997We discuss the entropy generation in quantum tunneling of a relativistic particle under the influence of a time varying force with the help of squeezing formalism. It is shown that if one associates classical coarse grained entropy to the phase space ... More

Abstract Swiss Cheese Space and the Classicalisation of Swiss CheesesMar 12 2015Feb 03 2016Swiss cheese sets are compact subsets of the complex plane obtained by deleting a sequence of open disks from a closed disk. Such sets have provided numerous counterexamples in the theory of uniform algebras. In this paper, we introduce a topological ... More

Normed algebras of differentiable functions on compact plane setsJan 16 2015We investigate the completeness and completions of the normed algebras $D^{(1)}(X)$ for perfect, compact plane sets $X$. In particular, we construct a radially self-absorbing, compact plane set $X$ such that the normed algebra $D^{(1)}(X)$ is not complete. ... More

Regularity and amenability conditions for uniform algebrasDec 24 2014We give a survey of the known connections between regularity conditions and amenability conditions in the setting of uniform algebras. For a uniform algebra $A$ we consider the set, $A_{lc}$, of functions in $A$ which are locally constant on a (varying) ... More

Strong regularity for uniform algebrasSep 14 1998A survey is given of the work on strong regularity for uniform algebras over the last thirty years, and some new results are proved, including the following. Let A be a uniform algebra on a compact space X and let E be the set of all those points x of ... More

Measures of Systemic RiskFeb 27 2015Oct 13 2016Systemic risk refers to the risk that the financial system is susceptible to failures due to the characteristics of the system itself. The tremendous cost of systemic risk requires the design and implementation of tools for the efficient macroprudential ... More

A note on ideal spaces of Banach AlgebrasSep 16 1998In a previous paper the second author introduced a compact topology on the space of closed ideals of a unital Banach algebra A. If A is separable then this topology is either metrizable or else neither Hausdorff nor first countable. Here it is shown that ... More

Spectral synthesis for Banach Algebras IISep 24 1999May 12 2000This paper continues the study of spectral synthesis and the topologies $\tau_{\infty}$ and $\tau_r$ on the ideal space of a Banach algebra, concentrating particularly on the class of Haagerup tensor products of C$^*$-algebras. For this class, it is shown ... More

Scalar Field Inhomogeneous CosmologiesNov 24 1995Some exact solutions for the Einstein field equations corresponding to inhomogeneous $G_2$ cosmologies with an exponential-potential scalar field which generalize solutions obtained previously are considered. Several particular cases are studied and the ... More

A General Method for Constructing Essential Uniform AlgebrasDec 26 2015Mar 04 2018A general method for constructing essential uniform algebras with prescribed properties is presented. Using the method, the following examples are constructed: an essential, natural, regular uniform algebra on the closed unit disc; an essential, natural ... More

Cosmologies with Two-Dimensional InhomogeneityNov 27 1995We present a new generating algorithm to construct exact non static solutions of the Einstein field equations with two-dimensional inhomogeneity. Infinite dimensional families of $G_1$ inhomogeneous solutions with a self interacting scalar field, or alternatively ... More

5D gravitational waves from complexified black ringsOct 20 2009Feb 01 2010In this paper we construct and briefly study the 5D time-dependent solutions of general relativity obtained via double analytic continuation of the black hole (Myers-Perry) and of the black ring solutions with a double (Pomeransky-Senkov) and a single ... More

On the denseness of the invertible group in Banach algebrasMar 26 2002We examine the condition that a complex Banach algebra $A$ have dense invertible group. We show that, for commutative algebras, this property is preserved by integral extensions. We also investigate the connections with an old problem in the theory of ... More

Removability of exceptional sets for differentiable and Lipschitz functionsDec 19 2014We discuss removability problems concerning differentiability and pointwise Lipschitz conditions for functions of a real variable. We prove that, in each of the settings under consideration, a set is removable if and only if it has no perfect subsets. ... More

A General Method for Constructing Essential Uniform AlgebrasDec 26 2015A general method for constructing essential uniform algebras with prescribed properties is presented. Using the method, the following examples are constructed: an essential, natural, regular uniform algebra on the closed unit disc; an essential, natural ... More

Detailed photometric analysis of young star groups in the galaxy NGC 300Aug 22 2016The purpose of this work is to understand the global characteristics of the stellar populations in NGC 300. In particular, we focused our attention on searching young star groups and study their hierarchical organization. The research was conducted using ... More

Disks in Expanding FRW UniversesJun 13 1997Oct 15 1997We construct exact solutions to Einstein equations which represent relativistic disks immersed into an expanding FRW Universe. It is shown that the expansion influences dynamical characteristics of the disks such as rotational curves, surface mass density, ... More

Particle Creation in the Bell-Szekeres SpacetimeNov 24 1995The quantization of a real massless scalar field in a spacetime produced in a collision of two electromagnetic plane waves with constant wave fronts is considered. The background geometry in the interaction region, the Bell-Szekeres solution, is locally ... More

Exponential-Potential Scalar Field Universes II: The Inhomogeneous ModelsSep 14 1993We obtain exact solutions for the Einstein equations with an exponential-potential scalar field (\(V=\Lambda e^{k\phi}\)) which represent simple inhomogeneous generalizations of Bianchi I cosmologies. Studying these equations numerically we find that ... More

Generating Black Strings in Higher DimensionsOct 22 2009Starting with a Zipoy-Voorhees line element we construct and study the three parameter family of solutions describing a deformed black string with arbitrary tension.

Exponential-Potential Scalar Field Universes I: The Bianchi I ModelsSep 14 1993We obtain a general exact solution of the Einstein field equations for the anisotropic Bianchi type I universes filled with an exponential-potential scalar field and study their dynamics. It is shown, in agreement with previous studies, that for a wide ... More

Completions of normed algebras of differentiable functionsOct 13 2003In this paper we look at normed spaces of differentiable functions on compact plane sets, including the spaces of infinitely differentiable functions originally considered by Dales and Davie. For many compact plane sets the classical definitions give ... More

HFF-DeepSpace Photometric Catalogs of the Twelve Hubble Frontier Fields, Clusters and Parallels: Photometry, Photometric Redshifts, and Stellar MassesJan 29 2018Jan 31 2018We present Hubble multi-wavelength photometric catalogs, including (up to) 17 filters with the Advanced Camera for Surveys and Wide Field Camera 3 from the ultra-violet to near-infrared for the Hubble Frontier Fields and associated parallels. We have ... More

A Super-Earth and two sub-Neptunes transiting the bright, nearby, and quiet M-dwarf TOI-270Mar 14 2019We report the Transiting Exoplanet Survey Satellite (TESS) discovery of three small planets transiting one of the brightest (K-mag 8.3) and nearest (22.5 parsec) M-dwarf hosts to date, TOI-270 (TIC 259377017). The system is observationally favourable, ... More

Scaling metagenome sequence assembly with probabilistic de Bruijn graphsDec 18 2011Jun 30 2012Deep sequencing has enabled the investigation of a wide range of environmental microbial ecosystems, but the high memory requirements for {\em de novo} assembly of short-read shotgun sequencing data from these complex populations are an increasingly large ... More

Evolution of Landau Levels into Edge States at an Atomically Sharp Edge in GrapheneMar 25 2012The quantum-Hall-effect (QHE) occurs in topologically-ordered states of two-dimensional (2d) electron-systems in which an insulating bulk-state coexists with protected 1d conducting edge-states. Owing to a unique topologically imposed edge-bulk correspondence ... More

Bloofi: Multidimensional Bloom FiltersJan 08 2015Sep 21 2016Bloom filters are probabilistic data structures commonly used for approximate membership problems in many areas of Computer Science (networking, distributed systems, databases, etc.). With the increase in data size and distribution of data, problems arise ... More

Photometric study of the young open cluster NGC 3293Jan 27 2003Deep and extensive CCD photometric observations $UBV(RI)_{C}H_{\alpha}$ were carried out in the area of the open cluster NGC 3293. The new data set allows to see the entire cluster sequence down to $M_{V} \approx +4.5$, revealing that stars with $M_{V} ... More

Entropy generation and inflation in wave collision induced pre-big-bang cosmologyApr 12 2000Sep 18 2000We study inflation and entropy generation in a recently proposed pre-big-bang model universe produced in a collision of gravitational and dilaton waves. It is shown that enough inflation occurs provided the incoming waves are sufficiently weak. We also ... More

Shadow Estimation Method for "The Episolar Constraint: Monocular Shape from Shadow Correspondence"Apr 15 2013Recovering shadows is an important step for many vision algorithms. Current approaches that work with time-lapse sequences are limited to simple thresholding heuristics. We show these approaches only work with very careful tuning of parameters, and do ... More