Results for "Gerard Schuster"

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Seismic Inversion by Newtonian Machine LearningApr 24 2019We present a wave-equation inversion method that inverts skeletonized data for the subsurface velocity model. The skeletonized representation of the seismic traces consists of the low-rank latent-space variables predicted by a well-trained autoencoder ... More
Multilayer Sparse Least Squares Migration=Deep Convolutional Neural NetworkApr 19 2019We recast the multilayered sparse inversion problem as a multilayered neural network problem. Unlike standard least squares migration (LSM) which finds the optimal reflectivity image, neural network least squares migration (NNLSM) finds both the optimal ... More
Inter-Coder Agreement for Nominal Scales: A Model-based ApproachAug 06 2012Inter-coder agreement measures, like Cohen's kappa, correct the relative frequency of agreement between coders to account for agreement which simply occurs by chance. However, in some situations these measures exhibit behavior which make their values ... More
Black Hole Evaporation: Sparsity in Analogue and General Relativistic Space-TimesJan 17 2019Our understanding of black holes changed drastically, when Stephen Hawking discovered their evaporation due to quantum mechanical processes. One core feature of this effect is both its similarity and simultaneous dissimilarity to classical black body ... More
Maximal rank subgroups and strong functoriality of the additive eigenconeAug 22 2016Let $G$ be a simple connected complex Lie group. The additive eigencone of $G$ is a polyhedral cone containing the set of solutions to the additive eigenvalue problem, a generalization of the Hermitian eigenvalue problem. The additive eigencone is functorial, ... More
The combinatorial multitude of fatty acids can be described by Fibonacci numbersMar 28 2013The famous series of Fibonacci numbers is defined by a recursive equation saying that each number is the sum of its two predecessors, with the initial condition that the first two numbers are equal to unity. Here, we show that the numbers of fatty acids ... More
Sur le lemme fondamental pour les groupes unitairesDec 18 2002Assuming the purity conjecture for the affine Springer fibers which has been formulated by Goresky, Kottwitz and MacPherson, we prove a geometric analog of the fundamental lemma for unitary groups. Our approach is similar to the one of Goresky, Kottwitz ... More
A crossing probability for critical percolation in two dimensionsMar 22 1996Apr 03 1996Langlands et al. considered two crossing probabilities, pi_h and pi_{hv}, in their extensive numerical investigations of critical percolation in two dimensions. Cardy was able to find the exact form of pi_h by treating it as a correlation function of ... More
Standard finite elements for the numerical resolution of the elliptic Monge-Ampere equation: mixed methodsJun 22 2014Jul 30 2015We prove a convergence result for a mixed finite element method for the Monge-Ampere equation to its weak solution in the sense of Aleksandrov. The unknowns in the formulation are the scalar variable and the Hessian matrix.
The Statistical and Econometric Analysis of Asylum Application Trends and their relationship to GDP in the EEAMay 13 2013The sharp decline in Ireland's economic performance in recent years has coincided with a recent fall in asylum applications. Simultaneously countries such as Switzerland are seeing increases in asylum numbers with evidence for greater numbers of Nigerian ... More
Sparse distributed representation, hierarchy, critical periods, metaplasticity: the keys to lifelong fixed-time learning and best-match retrievalJun 02 2018Among the more important hallmarks of human intelligence, which any artificial general intelligence (AGI) should have, are the following. 1. It must be capable of on-line learning, including with single/few trials. 2. Memories/knowledge must be permanent ... More
Future prospects: Merging data with modelsNov 01 2002Globular clusters are stellar dynamical systems which evolve on stellar evolutionary and both internal and external dynamical timescales. Quantitative comparison of cluster properties with realistic evolutionary dynamical models is becoming feasible, ... More
GAIA: Understanding the GalaxyOct 30 2001The GAIA Observatory, ESA's Cornerstone 6 mission, addresses the origin and evolution of our Galaxy, and a host of other scientific challenges. GAIA will provide unprecedented positional and radial velocity measurements with the accuracies needed to produce ... More
Dark Matter on small scales; Telescopes on large scalesMar 14 2007This article reviews recent progress in observational determination of the properties of dark matter on small astrophysical scales, and progress towards the European Extremely Large Telescope. Current results suggest some surprises: the central DM density ... More
The Splice BootstrapNov 22 2013This paper proposes a new bootstrap method to compute predictive intervals for nonlinear autoregressive time series model forecast. This method we call the splice boobstrap as it involves splicing the last p values of a given series to a suitably simulated ... More
On standard finite difference discretizations of the elliptic Monge-Ampere equationNov 12 2013Jul 30 2015Given an orthogonal lattice with mesh length h on a bounded convex domain, we propose to approximate the Aleksandrov solution of the Monge-Ampere equation by regularizing the data and discretizing the equation in a subdomain using the standard finite ... More
Representations of the Vertex Reinforced Jump Process as a mixture of Markov processes on $\mathbb{Z}^d$ and infinite treesMar 24 2019This paper concerns the Vertex Reinforced Jump Process (VRJP) and its representations as a Markov process in random environment. We show that all possible representations of the VRJP as a mixture of Markov processes can be expressed in a similar form, ... More
The strict AKNS hierarchy: its structure and solutionsAug 22 2017In this paper we discuss an integrable hierarchy of compatible Lax equations that is obtained by a wider deformation of a commutative algebra in the loop space of ${\rm sl}_{2}$ than that in the AKNS-case and whose Lax equations are based on a different ... More
Transformation de Fourier homogeneJul 16 2002In their proof of the Drinfeld-Langlands correspondence, Frenkel, Gaitsgory and Vilonen make use of a geometric Fourier transformation. Therefore, they work either with l-adic sheaves in characteristic p>0, or with D-modules in characteristic 0. Actually, ... More
Fibres de Springer et jacobiennes compactifieesApr 10 2002Dec 18 2002We identify, up to homeomorphisms, the affine Springer fibers for GL(n) on a local field of equal characteristics with some coverings of compactified jacobians of singular projective curves. This allows us to prove an irreducibility property of these ... More
Bounded confidence and Social networksNov 12 2003In the so-called bounded confidence model proposed by Deffuant et al, agents can influence each other's opinion provided that opinions are already sufficiently close enough. We here discuss the influence of possible social networks topologies on the dynamics ... More
The Science of Galaxy FormationAug 23 2008Our knowledge of the Universe remains discovery-led: in the absence of adequate physics-based theory, interpretation of new results requires a scientific methodology. Commonly, scientific progress in astrophysics is motivated by the empirical success ... More
Moduli space coordinates and excited state g-functionsJul 01 2011We consider the space of boundary conditions of Virasoro minimal models formed from the composition of a collection of flows generated by \phi_{1,3}. These have recently been shown to fall naturally into a sequence, each term having a coordinate on it ... More
Natural Density Distribution of Hermite Normal Forms of Integer MatricesSep 24 2010Aug 04 2011The Hermite Normal Form (HNF) is a canonical representation of matrices over any principal ideal domain. Over the integers, the distribution of the HNFs of randomly looking matrices is far from uniform. The aim of this article is to present an explicit ... More
A Chevalley's theorem in class C^rAug 26 2008Let W be a finite reflection group acting orthogonally on R^n, P be the Chevalley polynomial mapping determined by an integrity basis of the algebra of W-invariant polynomials, and h be the highest degree of the coordinate polynomials in P.There exists ... More
Strict versions of various matrix hierarchies related to SL(n)-loops and their combinationsNov 06 2017Let $\mathfrak{t}$ be a commutative Lie subalgebra of ${\rm sl}_{n}(\mathbb{C})$ of maximal dimension. We consider in this paper three spaces of $\mathfrak{t}$-loops that each get deformed in a different way. We require that the deformed generators of ... More
OPTICON: EC Optical Infrared Coordination Network for AstronomyMay 31 2001OPTICON, the ICN Optical Infrared Coordination Network for Astronomy, brings together for the first time the operators of all Europe's medium to large optical-infrared telescopes, the largest corresponding data archives, and several user representatives. ... More
A Gravity Model Analysis of Irish Merchandise Goods Exports under BrexitDec 20 2018We examine the effect of a Hard Brexit on Irish Exports using the PPML Gravity Model and Irish Exports data at the micro level. We find a hard Brexit could reduce Irish national income by over 9 billion euro annually and the effect would be sustained ... More
A Matched Pairs Analysis of International Protection Outcomes in IrelandMay 29 2017We examine over 40,000 International Protection (IP) determinations for non-EEA nationals covering a 16 year period in Ireland. We reconfigure these individual outcomes into a set of over 23,000 matched pairs based on combination of direct matching and ... More
Uniqueness in Law for a Class of Degenerate Diffusions with Continuous CovarianceMay 09 2011We study the martingale problem associated with the operator $L u = \partial_s u + 1/2 \sum_{i,j=1}^{d_0} a^{ij} \partial_{ij} u + \sum_{i,j=1}^d B^{ij} x^j \partial_i u$, where $d_0 \leq d$. We show that the martingale problem is well-posed when the ... More
Uniform limit of discrete convex functionsApr 03 2019We consider mesh functions which are discrete convex in the sense of Oberman. Analogous to the case of a uniformly bounded sequence of convex functions, we prove that the uniform limit on compact subsets of discrete convex mesh functions which are uniformly ... More
Uniqueness and stability result for Cauchy's equation of motion for a certain class of hyperelastic materialsFeb 04 2014Feb 05 2014We consider Cauchy's equation of motion for hyperelastic materials. The solution of this nonlinear initial-boundary value problem is the vector field which discribes the displacement which a particle of this material perceives when exposed to stress and ... More
Some notes on the abstraction operation for Multi-Terminal Binary Decision DiagramsMar 25 2013Oct 31 2013The starting point of this work are inaccurate statements found in the literature for Multi-terminal Binary Decision Diagrams (MTBDDs) regarding the well-definedness of the MTBDD abstraction operation. The statements try to relate an operation * on a ... More
Games for Active XML RevisitedDec 18 2014The paper studies the rewriting mechanisms for intensional documents in the Active XML framework, abstracted in the form of active context-free games. The safe rewriting problem studied in this paper is to decide whether the first player, Juliet, has ... More
Intrinsic Doping at YBCO-metal Interfaces: Quantitative ResultsFeb 05 2007Charge redistribution in high-Tc superconductors due to structural defects or interfaces is known to be crucial for electronic applications as the band structure is modified on a local scale. In order to investigate these effects in more detail, we address ... More
Convolutions and multiplier transformations of convex bodiesJul 31 2012Rotation intertwining maps from the set of convex bodies in Rn into itself that are continuous linear operators with respect to Minkowski and Blaschke addition are investigated. The main focus is on Blaschke-Minkowski homomorphisms. We show that such ... More
An iterative method to reconstruct the refractive index of a medium from time-of-flight measurementsOct 23 2015The article deals with a classical inverse problem: the computation of the refractive index of a medium from ultrasound time-of-flight (TOF) measurements. This problem is very popular in seismics but also for tomographic problems in inhomogeneous media. ... More
On the linearization of identifying the stored energy function of a hyperelastic material from full knowledge of the displacement fieldNov 13 2015We consider the nonlinear,inverse problem of computing the stored energy function of a hyperelastic material from the full knowledge of the displacement field. The displacement field is described as solution of the nonlinear, dynamic, elastic wave equation, ... More
Sequential subspace optimization for nonlinear inverse problemsFeb 22 2016In this work we discuss a method to adapt sequential subspace optimization (SESOP), which has so far been developed for linear inverse problems in Hilbert and Banach spaces, to the case of nonlinear inverse problems. We start by revising the well-known ... More
Characterization of the scintillation anisotropy in crystalline stilbene scintillator detectorsJun 21 2016This paper reports a series of measurements that characterize the directional dependence of the scintillation response of crystalline melt-grown and solution-grown stilbene to incident DT and DD neutrons. These measurements give the amplitude and pulse ... More
Investigating the anisotropic scintillation response in anthracene through neutron, gamma-ray, and muon measurementsOct 31 2015This paper reports a series of measurements that characterize the directional dependence of the scintillation response of crystalline anthracene to incident DT neutrons, DD neutrons, Cs-137 gamma rays, and, for the first time, cosmic ray muons. The neutron ... More
Searching for Light Dark Matter with the SLAC Millicharge ExperimentJul 25 2013New sub-GeV gauge forces ("dark photons") that kinetically mix with the photon provide a promising scenario for MeV-GeV dark matter, and are the subject of a program of searches at fixed-target and collider facilities around the world. In such models, ... More
Subalgebras of group cohomology defined by infinite loop spacesDec 17 2001We study natural subalgebras Ch_E(G) of group cohomology defined in terms of infinite loop spaces E and give representation theoretic descriptions of those based on QS^0 and the Johnson-Wilson theories E(n). We describe the subalgebras arising from the ... More
Lutwak-Petty projection inequalities for Minkowski valuations and their dualsAug 05 2019Lutwak's volume inequalities for polar projection bodies of all orders are generalized to polarizations of Minkowski valuations generated by even, zonal measures on the Euclidean unit sphere. This is based on analogues of mixed projection bodies for such ... More
Rotation invariant Minkowski classes of convex bodiesJul 31 2012A Minkowski class is a closed subset of the space of convex bodies in Euclidean space Rn which is closed under Minkowski addition and non-negative dilatations. A convex body in Rn is universal if the expansion of its support function in spherical harmonics ... More
$1/f^α$ noise from self-organized critical models with uniform drivingOct 11 2000Using the well-known Olami-Feder-Christensen model as our paradigm, we show how to modify uniform driven self-organized critical models to generate $1/f^\alpha$ noise. Our model can reproduce all the main features of $1/f^\alpha$ noise: (1) $\alpha$ is ... More
On the GL(V)-module structure of K(n)^*(BV)Nov 30 2007We study the question of whether the Morava K-theory of the classifying space of an elementary abelian group V is a permutation module (in either of two distinct senses) for the automorphism group of V. We use Brauer characters and computer calculations. ... More
FUSE and the Astrophysics of AGN and QSOsNov 14 2004The high spectral resolution and sensitivity of FUSE have enabled far-ultraviolet studies of AGN and QSOs that are a natural complement to observations using HST, Chandra, and XMM-Newton. Through synergistic use of the large sample of nearby AGN that ... More
Production networks and failure avalanchesJul 13 2005Although standard economics textbooks are seldom interested in production networks, modern economies are more and more based upon suppliers/customers interactions. One can consider entire sectors of the economy as generalised supply chains. We will take ... More
On the relativistic KMS condition for the P(φ)_2 modelSep 29 2006The relativistic KMS condition introduced by Bros and Buchholz provides a link between quantum statistical mechanics and quantum field theory. We show that for the $P(\phi)_2$ model at positive temperature, the two point function for fields satisfies ... More
The strong equivalence principle from gravitational gauge structureJul 05 2006May 22 2007Gravitational self-interactions are assumed to be determined by the covariant derivative acting on the Riemann-Christoffel field strength. Once imposed on a metric theory, this Yang-Mills gauge constraint extends the equality of gravitational mass and ... More
Mass Issues in Fundamental InteractionsNov 04 2008Driven by the mass problem, we raise some issues of the fundamental interactions in terms of non trivial commutation relations implemented within toy theories.
Probing integrable perturbations of conformal theories using singular vectors II: N=1 superconformal theoriesJul 03 1997In this work we pursue the singular-vector analysis of the integrable perturbations of conformal theories that was initiated in hep-th/9603088. Here we consider the detailed study of the N=1 superconformal theory and show that all integrable perturbations ... More
Generic colourful tori and inverse spectral transform for Hankel operatorsDec 06 2017This paper explores the regularity properties of an inverse spectral transform for Hilbert--Schmidt Hankel operators on the unit disc. This spectral transform plays the role of action-angles variables for an integrable infinite dimensional Hamiltonian ... More
In the transmission of information, the great potential of model-based coding with the SP theory of intelligenceDec 06 2016Model-based coding, described by John Pierce in 1961, has great potential to reduce the volume of information that needs to be transmitted in moving big data, without loss of information, from one place to another, or in lossless communications via the ... More
Convergence of finite difference schemes to the Aleksandrov solution of the Monge-Ampere equationJul 30 2015We present a technique for proving convergence to the Aleksandrov solution of the Monge-Ampere equation of a stable and consistent finite difference scheme. We also require a notion of discrete convexity with a stability property and a local equicontinuity ... More
A stratification on the moduli of K3 surfaces in positive characteristicNov 02 2015We review the results on the cycle classes of the strata defined by the height and the Artin invariant on the moduli of K3 surfaces in positive characteristic obtained in joint work with Katsura and Ekedahl. In addition we prove a new irreducibility result ... More
Chasing the Ghosts of Ibsen: A computational stylistic analysis of drama in translationJan 05 2015Research into the stylistic properties of translations is an issue which has received some attention in computational stylistics. Previous work by Rybicki (2006) on the distinguishing of character idiolects in the work of Polish author Henryk Sienkiewicz ... More
Dirichlet random walks of two stepsJan 04 2015Mar 23 2015Random walks of n steps taken into independent uniformly random directions in a d-dimensional Euclidean space (d larger than 1), are named Dirichlet when their step lengths are distributed according to a Dirichlet law. The latter continuous multivariate ... More
Complex Vector Lattices Via Functional CompletionsOct 21 2014We show that the Fremlin tensor product $C(X)\bar{\otimes}C(Y)$ is not square mean complete when X and Y are uncountable metrizable compact spaces. This motivates the definition of complexification of Archimedean vector lattices, the Fremlin tensor product ... More
Ill-posedness of the incompressible Euler equations in the $C^1$ spaceMay 08 2014We prove that the 2D Euler equations are not locally well-posed in $C^1$. Our approach relies on the technique of Lagrangian deformations and norm inflation of Bourgain and Li. We show that the assumption that the data-to-solution map is continuous in ... More
A proof challenge: multiple alignment and information compressionMar 04 2014These notes pose a "proof challenge": a proof, or disproof, of the proposition that "For any given body of information, I, expressed as a one-dimensional sequence of atomic symbols, a multiple alignment concept, described in the document, provides a means ... More
Optical Design and Active Optics Methods in AstronomyMar 15 2013Optical designs for astronomy involve implementation of active optics and adaptive optics from X-ray to the infrared. Developments and results of active optics methods for telescopes, spectrographs and coronagraph planet finders are presented. The high ... More
Could ART increase the population level incidence of TB?Feb 03 2013HIV increases the likelihood that a person will develop TB. Starting them on anti-retroviral therapy (ART) reduces their risk of TB but not to the level in HIV negative people. Since HIV-positive people who are on ART can expect to live a normal life ... More
Simplification and integration in computing and cognition: the SP theory and the multiple alignment conceptDec 02 2012The main purpose of this article is to describe potential benefits and applications of the SP theory, a unique attempt to simplify and integrate ideas across artificial intelligence, mainstream computing and human cognition, with information compression ... More
Effective integrable dynamics for some nonlinear wave equationOct 26 2011We consider the following degenerate half wave equation on the one dimensional torus $$\quad i\partial_t u-|D|u=|u|^2u, \; u(0,\cdot)=u_0. $$ We show that, on a large time interval, the solution may be approximated by the solution of a completely integrable ... More
Interpreting Winograd Schemas Via the SP Theory of Intelligence and Its Realisation in the SP Computer ModelOct 09 2018In 'Winograd Schema' (WS) sentences like "The city councilmen refused the demonstrators a permit because they feared violence" and "The city councilmen refused the demonstrators a permit because they advocated revolution", it is easy for adults to understand ... More
Why Jordan algebras are natural in statistics:quadratic regression implies Wishart distributionsApr 19 2010If the space $\mathcal{Q}$ of quadratic forms in $\mathbb{R}^n$ is splitted in a direct sum $\mathcal{Q}_1\oplus...\oplus \mathcal{Q}_k$ and if $X$ and $Y$ are independent random variables of $\mathbb{R}^n$, assume that there exist a real number $a$ such ... More
Meixner matrix ensemblesSep 23 2010Oct 18 2017We construct a family of matrix ensembles that fits Anshelevich's regression postulates for "Meixner laws on matrices". We show that the Laplace transform of a general n by n Meixner matrix ensemble satisfies a system of partial differential equations ... More
Thermal Quantum Fields with Spatially Cut-off Interactions in 1+1 Space-time DimensionsJul 25 2003We construct interacting quantum fields in 1+1 space-time dimensions, representing charged or neutral scalar bosons at positive temperature and zero chemical potential. Our work is based on prior work by Klein and Landau and Hoegh-Krohn. Generalized path ... More
Social PercolationAug 28 1999We introduce the simplest model which relates the emergence of collective social/economic phenomena to the existence of a (possibly self-organized) percolation transition. We suggest a series of extensions to financial, economic, political systems.
Relating the quantum mechanics of discrete systems to standard canonical quantum mechanicsApr 22 2012Discrete quantum mechanics is here defined to be a quantum theory of wave functions defined on integers P_i and Q_i, while canonical quantum mechanics is assumed to be based on wave functions on the real numbers, R^n. We study reversible mappings from ... More
A locally finite model for gravityApr 02 2008Matter interacting classically with gravity in 3+1 dimensions usually gives rise to a continuum of degrees of freedom, so that, in any attempt to quantize the theory, ultraviolet divergences are nearly inevitable. Here, we investigate matter of a form ... More
The mathematical basis for deterministic quantum mechanicsApr 03 2006Jun 26 2006If there exists a classical, i.e. deterministic theory underlying quantum mechanics, an explanation must be found of the fact that the Hamiltonian, which is defined to be the operator that generates evolution in time, is bounded from below. The mechanism ... More
Confinement at Large NcAug 24 2004A discussion is given of the confinement mechanism in terms of the Abelian projection scheme, for a general number Nc of colors. There is a difficulty in the Nc to infinity limit that requires a careful treatment, as the charges of the condensing magnetic ... More
On Peculiarities and Pit Falls in Path IntegralsAug 07 2002Path integrals can be rigorously defined only in low dimensional systems where the small distance limit can be taken. Particularly non-trivial models in more than four dimensions can only be handled with considerable amount of speculation. In this lecture ... More
How Does God Play Dice? (Pre-)Determinism at the Planck ScaleApr 25 2001In deterministic theories, one can start from a set of ontological states to formulate the dynamical laws, but these may not be directly observable. Observable are only equivalence classes of states, and these will span a basis of "beables", to be promoted ... More
Determinism and Dissipation in Quantum Gravity, Erice lectureMar 01 2000May 16 2000Without invalidating quantum mechanics as a principle underlying the dynamics of a fundamental theory, it is possible to ask for even more basic dynamical laws that may yield quantum mechanics as the machinery needed for its statistical analysis. In conventional ... More
The firewall transformation for black holes and some of its implicationsDec 27 2016Sep 08 2017A promising strategy for better understanding space and time at the Planck scale, is outlined and further pursued. It is explained in detail, how black hole unitarity demands the existence of transformations that can remove firewalls. This must then be ... More
Hamiltonian formalism for integer-valued variables and integer time steps and a possible application in quantum physicsDec 04 2013Most classical mechanical systems are based on dynamical variables whose values are real numbers. Energy conservation is then guaranteed if the dynamical equations are phrased in terms of a Hamiltonian function, which then leads to differential equations ... More
Unitarity in the Brout-Englert-Higgs Mechanism for GravityAug 23 2007Jan 07 2008Just like the vector bosons in Abelian and non-Abelian gauge theories, gravitons can attain mass by spontaneous local symmetry breaking. The question is whether this can happen in a Lorentz-invariant way. We consider the use of four scalar fields that ... More
The Free-Will Postulate in Quantum MechanicsJan 15 2007The so-called "free will axiom" is an essential ingredient in many discussions concerning hidden variables in quantum mechanics. In this paper we argue that "free will" can be defined in different ways. The definition usually employed is clearly invalid ... More
Inverse spectral theory for a class of non-compact Hankel operatorsMar 16 2018We characterize all bounded Hankel operators $\Gamma $ such that $\Gamma^*\Gamma$ has finite spectrum. We identify spectral data corresponding to such operators and construct inverse spectral theory including the characterization of these spectral data. ... More
"Antiferromagnetism" in social relations and Bonabeau modelDec 28 2006We here present a fixed agents version of an original model of the emergence of hierarchies among social agents first introduced by Bonabeau \textit{et al}. Having interactions occurring on a social network rather than among 'walkers' doesn't drastically ... More
Meixner matrix ensemblesSep 23 2010May 03 2011We construct a family of matrix ensembles that fits Anshelevich's regression postulates for "Meixner laws on matrices". We show that the Laplace transform of a general n by n Meixner matrix ensemble satisfies a system of partial differential equations ... More
Dynamical friction in dwarf galaxiesFeb 19 1998We present a simplified analytic approach to the problem of the spiraling of a massive body orbiting within the dark halo of a dwarf galaxy. This dark halo is treated as the core region of a King distribution of dark matter particles, in consistency with ... More
Black hole mass and angular momentum in topologically massive gravityJun 02 2007Sep 27 2007We extend the Abbott-Deser-Tekin approach to the computation of the Killing charge for a solution of topologically massive gravity (TMG) linearized around an arbitrary background. This is then applied to evaluate the mass and angular momentum of black ... More
Loss of continuity of the solution map for the Euler equations in $α$-modulation and Hölder spacesDec 15 2014We study the incompressible Euler equations in the $\alpha$-modulation $M^{s,\alpha}_{p,q}$ and H\"older $C^{1+\sigma}$ spaces on the plane. We show that for these spaces the associated data-to-solution map is not continuous on bounded sets.
Big data and the SP theory of intelligenceJun 13 2013Mar 31 2014This article is about how the "SP theory of intelligence" and its realisation in the "SP machine" may, with advantage, be applied to the management and analysis of big data. The SP system -- introduced in the article and fully described elsewhere -- may ... More
The SP theory of intelligence: an overviewJun 13 2013Jan 07 2015This article is an overview of the "SP theory of intelligence". The theory aims to simplify and integrate concepts across artificial intelligence, mainstream computing and human perception and cognition, with information compression as a unifying theme. ... More
The Euler and Navier-Stokes equations on the hyperbolic planeMay 24 2012We show that non-uniqueness of the Leray-Hopf solutions of the Navier--Stokes equation on the hyperbolic plane observed in arXiv:1006.2819 is a consequence of the Hodge decomposition. We show that this phenomenon does not occur on the hyperbolic spaces ... More
On the Spin Bias of Satellite Galaxies in the Local Group-like EnvironmentMar 04 2013Apr 30 2013We utilize the Millennium-II simulation databases to study the spin bias of dark subhalos in the Local Group-like systems which have two prominent satellites with comparable masses. Selecting the group-size halos with total mass similar to that of the ... More
Spectral inverse problems for compact Hankel operatorsJan 24 2012Given two arbitrary sequences $(\lambda_j)_{j\ge 1}$ and $(\mu_j)_{j\ge 1}$ of real numbers satisfying $$|\lambda_1|>|\mu_1|>|\lambda_2|>|\mu_2|>...>| \lambda_j| >| \mu_j| \to 0\ ,$$ we prove that there exists a unique sequence $c=(c_n)_{n\in\Z_+}$, real ... More
Software engineering and the SP Theory of IntelligenceAug 18 2017Aug 05 2018This paper describes a novel approach to software engineering derived from the "SP Theory of Intelligence" and its realisation in the "SP Computer Model". Despite superficial appearances, it is shown that many of the key ideas in software engineering ... More
Exploring modular forms and the cohomology of local systems on moduli spaces by counting pointsApr 10 2016This is a report on a joint project in experimental mathematics with Jonas Bergstr\"om and Carel Faber where we obtain information about modular forms by counting curves over finite fields.
The SP theory of intelligence and the representation and processing of knowledge in the brainApr 19 2016May 12 2016The "SP theory of intelligence", with its realisation in the "SP computer model", aims to simplify and integrate observations and concepts across AI-related fields, with information compression as a unifying theme. This paper describes how abstract structures ... More
Interferometric Observations of Rapidly Rotating StarsApr 11 2012Optical interferometry provides us with a unique opportunity to improve our understanding of stellar structure and evolution. Through direct observation of rotationally distorted photospheres at sub-milliarcsecond scales, we are now able to characterize ... More
Coevo: a collaborative design platform with artificial agentsApr 30 2019We present Coevo, an online platform that allows both humans and artificial agents to design shapes that solve different tasks. Our goal is to explore common shared design tools that can be used by humans and artificial agents in a context of creation. ... More
Heights and metrics with logarithmic singularitiesApr 08 2007We prove lower bound and finiteness properties for arakelovian heights with respect to pre-log-log hermitian ample line bundles. These heights were introduced by Burgos, Kramer and K\"uhn, in their extension of the arithmetic intersection theory of Gillet ... More
Improvements in closest point search based on dual HKZ-basesJan 25 2012In this paper we review the technique to solve the CVP based on dual HKZ-bases by J. Bloemer. The technique is based on the transference theorems given by Banaszczyk which imply some necessary conditions on the coefficients of the closest vectors with ... More