Results for "Thomas Willum Hansen"

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A deep learning approach to identify local structures in atomic-resolution transmission electron microscopy imagesFeb 08 2018Recording atomic-resolution transmission electron microscopy (TEM) images is becoming increasingly routine. A new bottleneck is then analyzing this information, which often involves time-consuming manual structural identification. We have developed a ... More
A deep learning approach to identify local structures in atomic-resolution transmission electron microscopy imagesFeb 08 2018Feb 09 2018Recording atomic-resolution transmission electron microscopy (TEM) images is becoming increasingly routine. A new bottleneck is then analyzing this information, which often involves time-consuming manual structural identification. We have developed a ... More
Random-Facet and Random-Bland require subexponential time even for shortest pathsOct 28 2014The Random-Facet algorithm of Kalai and of Matousek, Sharir and Welzl is an elegant randomized algorithm for solving linear programs and more general LP-type problems. Its expected subexponential time of $2^{\tilde{O}(\sqrt{m})}$, where $m$ is the number ... More
A Fast Interior Point Method for Atomic Norm Soft ThresholdingMar 02 2018The atomic norm provides a generalization of the $\ell_1$-norm to continuous parameter spaces. When applied as a sparse regularizer for line spectral estimation the solution can be obtained by solving a convex optimization problem. This problem is known ... More
Strategy iteration is strongly polynomial for 2-player turn-based stochastic games with a constant discount factorAug 03 2010Ye showed recently that the simplex method with Dantzig pivoting rule, as well as Howard's policy iteration algorithm, solve discounted Markov decision processes (MDPs), with a constant discount factor, in strongly polynomial time. More precisely, Ye ... More
CO2 hydrate dissociation at low temperatures - formation and annealing of ice IcOct 27 2015Dissociation of gas hydrates below 240 K leads to the formation of a metastable form of water ice, so called cubic ice (Ic). Through its defective nature and small particle size the surface film composed of such material is incapable of creating any significant ... More
Magnetoelastic effects in multiferroic HoMnO$_3$Dec 18 2012We have investigated magnetoelastic effects in multiferroic HoMnO$_3$ below the antiferromagnetic phase transition $T_N \approx 75$ K by neutron powder diffraction. The lattice parameter $a$ of the hexagonal unit cell of HoMnO$_3$ decrease in the usual ... More
Low-Scaling Algorithm for Nudged Elastic Band Calculations Using a Surrogate Machine Learning ModelNov 19 2018We present the incorporation of a surrogate Gaussian Process Regression (GPR) atomistic model to greatly accelerate the rate of convergence of classical Nudged Elastic Band (NEB) calculations. In our surrogate model approach, the cost of converging the ... More
Suppression of Antiferroelectric State in NaNbO3 at High Pressure from In Situ Neutron DiffractionOct 16 2012We report direct experimental evidence of antiferroelectric to paraelectric phase transition under pressure in NaNbO3 using neutron diffraction at room temperature. The paraelectric phase is found to stabilize above 8 GPa and its crystal structure has ... More
Faster Algorithms for Computing Maximal 2-Connected Subgraphs in Sparse Directed GraphsMay 30 2017Connectivity related concepts are of fundamental interest in graph theory. The area has received extensive attention over four decades, but many problems remain unsolved, especially for directed graphs. A directed graph is 2-edge-connected (resp., 2-vertex-connected) ... More
Lattice constants and expansivities of gas hydrates from 10K up to the stability limitOct 23 2015In a combination of neutron and synchrotron diffraction the lattice constants and expansivities of hydrogenated and deuterated CH4-, CO2-, Xe- (structure type I) and N2-hydrate (structure type II) from 10 K up to the stability limit under pressure were ... More
Kinetic Simulation of Filament Growth Dynamics in Memristive Electrochemical Metallization DevicesSep 01 2015Oct 31 2015In this work we report on kinetic Monte-Carlo calculations of resistive switching and the underlying growth dynamics of filaments in an electrochemical metallization device consisting of an Ag/TiO2/Pt sandwich-like thin film system. The developed model ... More
An Enhanced Lumped Element Electrical Model of a Double Barrier Memristive DeviceJan 19 2017The massive parallel approach of neuromorphic circuits leads to effective methods for solving complex problems. It has turned out that resistive switching devices with a continuous resistance range are potential candidates for such applications. These ... More
ARRIVAL: Next Stop in CLSFeb 21 2018We study the computational complexity of ARRIVAL, a zero-player game on $n$-vertex switch graphs introduced by Dohrau, G\"{a}rtner, Kohler, Matou\v{s}ek, and Welzl. They showed that the problem of deciding termination of this game is contained in $\text{NP} ... More
Absence of Stress-induced Anisotropy during Brittle Deformation in Antigorite SerpentiniteJun 23 2018Jan 06 2019Knowledge of the seismological signature of serpentinites during deformation is fundamental for interpreting seismic observations in subduction zones, but this has yet to be experimentally constrained. We measured compressional and shear wave velocities ... More
Access and in situ Growth of Phosphorene-Precursor Black PhosphorusJun 27 2014Jun 30 2014Single crystals of orthorhombic black phosphorus can be grown by a short way transport reaction from red phosphorus and Sn/SnI4 as mineralization additive. Sizes of several millimeters can be realized with high crystal quality and purity, making a large ... More
Universal coefficients for overconvergent cohomology and the geometry of eigenvarietiesSep 04 2012Oct 01 2012We prove a universal coefficients theorem for the overconvergent cohomology modules introduced by Ash and Stevens, and give several applications. In particular, we sketch a very simple construction of eigenvarieties using overconvergent cohomology and ... More
The Petersson norm of the Jacobi theta functionOct 03 2011We compute the Petersson norm of the Jacobi theta function, by a simple application of the Rankin-Selberg method and a little trick.
Intrinsic Hölder continuity of harmonic functionsOct 20 2015Nov 09 2016In a setting, where only exit measures are given, as they are associated with a right continuous strong Markov process on a separable metric space, we provide simple criteria for scaling invariant H\"older continuity of bounded harmonic functions with ... More
Equicontinuity of harmonic functions and compactness of potential kernelsApr 29 2019Apr 30 2019Within the framework of balayage spaces (the analytical equivalent of nice Hunt processes), we prove equicontinuity of bounded families of harmonic functions and apply it to obtain criteria for compactness of potential kernels.
Efficient demultiplexed single-photon source with a quantum dot coupled to a nanophotonic waveguideMar 21 2019Planar nanostructures allow near-ideal extraction of emission from a quantum emitter embedded within, thereby realizing deterministic single-photon sources. Such a source can be transformed into M single-photon sources by implementing active temporal-to-spatial ... More
The fast track to Löwner's theoremDec 01 2011Feb 03 2013The operator monotone functions defined in the positive half-line are of particular importance. We give a version of the theory in which integral representations for these functions can be established directly without invoking L\"owner's detailed analysis ... More
Monotone trace functions of several variablesJun 19 2006We investigate monotone operator functions of several variables under a trace or a trace-like functional. In particular, we prove the inequality \tau(x_1... x_n)\le\tau(y_1... y_n) for a trace \tau on a C^*-algebra and abelian n-tuples (x_1,...,x_n)\le ... More
Quantum entropy derived from first principlesApr 18 2016Oct 21 2016The most fundamental properties of quantum entropy are derived by considering the union of two ensembles. We discuss the limits these properties put on an entropy measure and obtain that they uniquely determine the form of the entropy functional up to ... More
Multivariate extensions of the Golden-Thompson inequalityJun 22 2014Jul 02 2014We study concave trace functions of several operator variables and formulate and prove multivariate generalisations of the Golden-Thompson inequality. The obtained results imply that certain functionals in quantum statistical mechanics have bounds of ... More
Convex multivariate operator meansJun 18 2018Aug 27 2018The dominant method for defining multivariate operator means is to express them as fix-points under a contraction with respect to the Thompson metric. Although this method is powerful, it crucially depends on monotonicity. We are developing a technique ... More
Jensen's inequality for conditional expectationsSep 22 2006We study conditional expectations generated by an abelian $ C^* $-subalgebra in the centralizer of a positive functional. We formulate and prove Jensen's inequality for functions of several variables with respect to this type of conditional expectations, ... More
Applications of integrand reduction to two-loop five-point scattering amplitudes in QCDJul 25 2018Sep 25 2018We review the current state-of-the-art in integrand level reduction for five-point scattering amplitudes at two loops in QCD. We present some benchmark results for the evaluation of the leading colour two-loop five-gluon amplitudes in the physical region ... More
Characterization of a scintillating lithium glass ultra-cold neutron detectorAug 08 2016Nov 08 2016A $^{6}$Li glass based scintillation detector developed for the TRIUMF neutron electric dipole moment experiment was characterized using the ultra-cold neutron source at the Paul Scherrer Institute (PSI). The data acquisition system for this detector ... More
Beta Beams Implementation at CERNSep 09 2011Beta Beam,the concept of generating a pure and intense (anti) neutrino beam by letting accelerated radioactive ions beta decay in a storage ring, called Decay Ring (DR), is the base of one of the proposed next generation neutrino oscillation facilities, ... More
Unavoidable collections of balls for processes with isotropic unimodal Green functionMar 01 2014Mar 19 2014Let us suppose that we have a right continuous Markov semigroup on $R^d$, $d\ge 1$, such that its potential kernel is given by convolution with a function $G_0=g(|\cdot|)$, where $g$ is decreasing, has a mild lower decay property at zero, and a very weak ... More
Non-commutative Hardy inequalitiesJun 04 2008Mar 02 2009We extend Hardy's inequality from sequences of non-negative numbers to sequences of positive semi-definite operators if the parameter p satisfies 1<p<=2, and to operators under a trace for arbitrary p>1. Applications to trace functions are given. We introduce ... More
Operator monotone functions of several variablesMay 14 2002We propose a notion of operator monotonicity for functions of several variables, which extends the well known notion of operator monotonicity for functions of only one variable. The notion is chosen such that a fundamental relationship between operator ... More
Darning and gluing of diffusionsJan 26 2016Mar 06 2016We introduce darning of compact sets (darning and gluing of finite unions of compact sets), which are not thin at any of their points, in a potential-theoretic framework which may be described, analytically, in terms of harmonic kernels/harmonic functions ... More
Hölder continuity of harmonic functions for Hunt processes with Green functionFeb 23 2015Let $(X,\mathcal W)$ be a balayage space, $1\in \mathcal W$, or - equivalently - let $\mathcal W$ be the set of excessive functions of a Hunt process on a locally compact space $X$ with countable base such that $\mathcal W$ separates points, every function ... More
Liouville property, Wiener's test and unavoidable sets for Hunt processesSep 26 2014Jan 27 2015Let $(X,\mathcal W)$ be a balayage space, $1\in \mathcal W$, or - equivalently - let $\mathcal W$ be the set of excessive functions of a Hunt process on a locally compact space $X$ with countable base such that $\mathcal W$ separates points, every function ... More
Magnetic structure of the magnetocaloric compound AlFe2B2Jan 08 2016The crystal and magnetic structures of AlFe2B2 have been studied with a combination of X-ray and neutron diffraction and electronic structure calculations. The magnetic and magnetocaloric properties have been investigated by magnetisation measurements. ... More
Failure properties of loaded fiber bundles having a lower cutoff in fiber threshold distributionJun 19 2004May 24 2005Presence of lower cutoff in fiber threshold distribution may affect the failure properties of a bundle of fibers subjected to external load. We investigate this possibility both in a equal load sharing (ELS) fiber bundle model and in local load sharing ... More
Web data mining for public health purposesMay 02 2019For a long time, public health events, such as disease incidence or vaccination activity, have been monitored to keep track of the health status of the population, allowing to evaluate the effect of public health initiatives and to decide where resources ... More
Solving POMDPs by Searching in Policy SpaceJan 30 2013Most algorithms for solving POMDPs iteratively improve a value function that implicitly represents a policy and are said to search in value function space. This paper presents an approach to solving POMDPs that represents a policy explicitly as a finite-state ... More
Quantum Codes from Toric SurfacesMar 20 2012A theory for constructing quantum error correcting codes from Toric surfaces by the Calderbank-Shor-Steane method is presented. In particular we study the method on toric Hirzebruch surfaces. The results are obtained by constructing a dualizing differential ... More
Nearly hyperharmonic functions and Jensen measuresMay 15 2017Let $(X,\mathcal H)$ be a $\mathcal P$-harmonic space and assume for simplicity that constants are harmonic. Given a numerical function $\varphi$ on $X$ which is locally lower bounded, let \begin{equation*} J_\varphi(x):=\sup\{\int^\ast \varphi\,d\mu(x)\colon ... More
Reduced functions and Jensen measuresNov 05 2016Feb 08 2017Let $\varphi$ be a locally upper bounded Borel measurable function on a Greenian open set $\Omega$ in $R^d$ and, for every $x\in \Omega$, let $v_\varphi(x)$ denote the infimum of the integrals of $\varphi$ with respect to Jensen measures for $x$ on $\Omega$. ... More
A full space-time convergence order analysis of operator splittings for linear dissipative evolution equationsDec 18 2015The Douglas--Rachford and Peaceman--Rachford splitting methods are common choices for temporal discretizations of evolution equations. In this paper we combine these methods with spatial discretizations fulfilling some easily verifiable criteria. In the ... More
Diagonal Acceleration for Covariance Matrix Adaptation Evolution StrategiesMay 14 2019We introduce an acceleration for covariance matrix adaptation evolution strategies (CMA-ES) by means of adaptive diagonal decoding (dd-CMA). This diagonal acceleration endows the default CMA-ES with the advantages of separable CMA-ES without inheriting ... More
Jucys-Murphy operators for Soergel bimodulesJul 12 2016We produce Jucys-Murphy elements for the diagrammatical category of Soergel bimodules associated with general Coxeter groups, and use them to diagonalize the bilinear form on the cell modules. This gives rise to an expression for the determinant of the ... More
S-duality in AdS/CFT magnetohydrodynamicsJul 16 2009We study the nonlinear hydrodynamics of a 2+1 dimensional charged conformal fluid subject to slowly varying external electric and magnetic fields. Following recent work on deriving nonlinear hydrodynamics from gravity, we demonstrate how long wavelength ... More
Scaling invariant Harnack inequalities in a general settingApr 06 2016Jul 13 2016In a setting, where only "exit measures" are given, as they are associated with an arbitrary right continuous strong Markov process on a separable metric space, we provide simple criteria for the validity of Harnack inequalities for positive harmonic ... More
Unavoidable sets and harmonic measures living on small setsJun 23 2013Mar 01 2014Given a connected open set $U\ne\emptyset$ in $ R^d$, $d\ge 2$, a relatively closed set $A$ in $U$ is called \emph{unavoidable in $U$}, if Brownian motion, starting in $x\in U\setminus A$ and killed when leaving $U$, hits $A$ almost surely or, equivalently, ... More
On $p$-adic $L$-functions for Hilbert modular formsOct 15 2017We construct $p$-adic $L$-functions associated with $p$-refined cohomological cuspidal Hilbert modular forms over any totally real field under a mild hypothesis. Our construction is canonical, varies naturally in $p$-adic families, and does not require ... More
Jensen measures in potential theoryJul 08 2010It is shown that, for open sets in classical potential theory and - more generally - for elliptic harmonic spaces, the set of Jensen measures for a point is a simple union of closed faces of a compact convex set which has been thoroughly studied a long ... More
Variational representations related to Tsallis relative entropyJan 21 2019We develop variational representations for the deformed logarithmic and exponential functions and use them to obtain variational representations related to the quantum Tsallis relative entropy. We extend Golden-Thompson's trace inequality to deformed ... More
Differential analysis of matrix convex functions IIMar 09 2007We continue the analysis in [3] of matrix convex functions of a fixed order defined in a real interval by differential methods as opposed to the characterization in terms of divided differences given by Kraus [5]. We amend and improve some points in the ... More
Semipolar sets and intrinsic Hausdorff measureNov 24 2017Given a "Green function" $G$ on a locally compact space $X$ with countable base, a Borel set $A$ in $X$ is called $G$-semipolar, if there is no measure $\nu\ne 0$ supported by $A$ such that $G\nu:=\int G(\cdot,y)\,d\nu(y)$ is a continuous real function ... More
Nonlinear Magnetohydrodynamics from GravityNov 21 2008Jan 08 2009We apply the recently established connection between nonlinear fluid dynamics and AdS gravity to the case of the dyonic black brane in AdS_4. This yields the equations of fluid dynamics for a 2+1 dimensional charged fluid in a background magnetic field. ... More
A q-Analogue of Kempf's vanishing theoremMay 03 2009We use deep properties of Kashiwara's crystal basis to show that the induction functor $ {H}^0 (-) $ introduced by Andersen, Polo and Wen satisfies an analogon of Kempf's vanishing Theorem.
Mendes France and thermodynamical spectra: a comparative study of contractive and expansive fractal processesJul 10 2009This paper presents a comparative study of two families of curves in R(n). The first ones comprise self-similar bounded fractals obtained by contractive processes, and have a non-integer Hausdorff dimension. The second ones are unbounded, locally rectifiable, ... More
Toward a Spectral Theory of Cellular SheavesAug 04 2018This paper outlines a program in what one might call spectral sheaf theory --- an extension of spectral graph theory to cellular sheaves. By lifting the combinatorial graph Laplacian to the Hodge Laplacian on a cellular sheaf of vector spaces over a regular ... More
Nearly hyperharmonic functions are infima of excessive functionsSep 23 2018Nov 13 2018Let $\mathfrak X$ be a Hunt process on a locally compact space $X$ such that the set $\mathcal E_{\mathfrak X}$ of its Borel measurable excessive functions separates points, every function in $\mathcal E_{\mathfrak X}$ is the supremum of its continuous ... More
Some remarks on Ext groupsMay 25 2009May 27 2009We calculate certain ext-groups between modules for a linear algebraic group. The results are in agreement with the Lusztig conjecture.
Convergence analysis of domain decomposition based time integrators for degenerate parabolic equationsAug 04 2017Domain decomposition based time integrators allow the usage of parallel and distributed hardware, making them well-suited for the temporal discretization of parabolic systems, in general, and degenerate parabolic problems, in particular. The latter is ... More
Capillary-Driven Instability of Immiscible Fluid Interfaces Flowing in Parallel in Porous MediaSep 20 2007Jun 04 2008When immiscible wetting and non-wetting fluids move in parallel in a porous medium, an instability may occur at sufficiently high capillary numbers so that interfaces between the fluids initially held in place by the porous medium are mobilized. A boundary ... More
Sextet Model with Wilson FermionsOct 25 2016Mar 24 2017We present new results from our ongoing study of the SU(3) sextet model with two flavors in the two-index symmetric representation of the gauge group. In the simulations use unimproved Wilson fermions to investigate the infrared properties of the model. ... More
Chemical tagging and the second r-processDec 18 2012Elements in the range 37 < Z < 47 provide key information on their formation process. Several studies have shown that some of these elements are formed by an r-process, that differs from the main r-process creating europium. Through a detailed abundance ... More
Quantile Models with EndogeneityMar 28 2013In this article, we review quantile models with endogeneity. We focus on models that achieve identification through the use of instrumental variables and discuss conditions under which partial and point identification are obtained. We discuss key conditions, ... More
Secret Sharing Schemes with a large number of players from Toric VarietiesOct 16 2014Mar 13 2016A general theory for constructing linear secret sharing schemes over a finite field $\Fq$ from toric varieties is introduced. The number of players can be as large as $(q-1)^r-1$ for $r\geq 1$. We present general methods for obtaining the reconstruction ... More
Hunt's hypothesis (H) and the triangle property of the Green functionNov 11 2014Let $X$ be a locally compact abelian group with countable base and let $\mathcal W$ be a convex cone of positive numerical functions on $X$ which is invariant under the group action and such that $(X,\mathcal W)$ is a balayage space or (equivalently, ... More
An inequality for expectation of means of positive random variablesAug 30 2016Suppose that $X,Y$ are positive random variable and $m$ a numerical (commutative) mean. We prove that the inequality ${\rm E} (m(X,Y)) \leq m({\rm E} (X), {\rm E} (Y))$ holds if and only if the mean is generated by a concave function. With due changes ... More
First Class Constrained Systems and Twisting of Courant Algebroids by a Closed 4-formApr 04 2009We show that in analogy to the introduction of Poisson structures twisted by a closed 3-form by Park and Klimcik-Strobl, the study of three dimensional sigma models with Wess-Zumino term leads in a likewise way to twisting of Courant algebroid structures ... More
Popularizing mathematics: from eight to infinityMay 01 2003It is rare to succeed in getting mathematics into ordinary conversation without meeting all kinds of reservations. In order to raise public awareness of mathematics effectively, it is necessary to modify such attitudes. In this paper, we point to some ... More
Linear Convergence on Positively Homogeneous Functions of a Comparison Based Step-Size Adaptive Randomized Search: the (1+1) ES with Generalized One-fifth Success RuleOct 31 2013In the context of unconstraint numerical optimization, this paper investigates the global linear convergence of a simple probabilistic derivative-free optimization algorithm (DFO). The algorithm samples a candidate solution from a standard multivariate ... More
SU(3) sextet model with Wilson fermionsOct 24 2017We present our final results for the SU(3) sextet model with the non-improved Wilson fermion discretization. We find evidence for several phases of the lattice model, including a bulk phase with broken chiral symmetry. We study the transition between ... More
Materials in Participatory Design ProcessesMar 21 2017This dissertation presents three years of academic inquiry into the question of what role materials play in interaction design and participatory design processes. The dissertation aims at developing conceptual tools, based on Deweys pragmatism, for understanding ... More
High order splitting schemes with complex timesteps and their application in mathematical financeOct 19 2012High order splitting schemes with complex timesteps are applied to Kolmogorov backward equations stemming from stochastic differential equations in Stratonovich form. In the setting of weighted spaces, the necessary analyticity of the split semigroups ... More
Generalized Huygens principle with pulsed-beam waveletsApr 04 2009Apr 30 2009Huygens' principle has a well-known problem with back-propagation due to the spherical nature of the secondary wavelets. We solve this by analytically continuing the surface of integration. If the surface is a sphere of radius $R$, this is done by complexifying ... More
A Convergence Analysis of the Peaceman--Rachford Scheme for Semilinear Evolution EquationsDec 18 2015The Peaceman--Rachford scheme is a commonly used splitting method for discretizing semilinear evolution equations, where the vector fields are given by the sum of one linear and one nonlinear dissipative operator. Typical examples of such equations are ... More
Mean Field Theory of Localization in the Fuse ModelMar 08 2004Nov 27 2005We propose a mean field theory for the localization of damage in a quasistatic fuse model on a cylinder. Depending on the quenched disorder distribution of the fuse thresholds, we show analytically that the system can either stay in a percolation regime ... More
Harnack inequalities for Hunt processes with Green functionOct 12 2014Feb 09 2015Let $(X,\mathcal W)$ be a balayage space, $1\in \mathcal W$, or - equivalently - let $\mathcal W$ be the set of excessive functions of a Hunt process on a locally compact space $X$ with countable base such that $\mathcal W$ separates points, every function ... More
Champagne subdomains with unavoidable bubblesJul 31 2012A champagne subdomain of a connected open set $U\ne\emptyset$ in $R^d$, $d\ge 2$, is obtained omitting pairwise disjoint closed balls $\bar{B}(x,r_x)$, $x\in X$, the bubbles, where $X$ is an infinite, locally finite set in $U$. The union $A$ of these ... More
Champagne subregions with unavoidable bubblesJun 07 2012Jun 17 2012A champagne subregion of a connected open set $U\ne\emptyset$ in $R^d$, $d\ge 2$, is obtained omitting pairwise disjoint closed balls $\bar B(x, r_x)$, $x\in X$, the bubbles, where $X$ is a locally finite set in $U$. The union $A$ of these balls may be ... More
Convexity of limits of harmonic measuresAug 10 2006It is shown that, given a point $x\in\mathbbm{R}^d$, $d\ge 2$, and open sets $U_1,...,U_k$ containing $x$, any convex combination of the harmonic measures for $x$ with respect to $U_n$, $1\le n\le k$, is the limit of a sequence of harmonic measures for ... More
Cluster evolution in steady-state two-phase flow in porous mediaNov 24 2005Jan 05 2006We report numerical studies of the cluster development of two-phase flow in a steady-state environment of porous media. This is done by including biperiodic boundary conditions in a two-dimensional flow simulator. Initial transients of wetting and non-wetting ... More
Similarities between structural distortions under pressure and chemical doping in superconducting BaFe2As2Dec 11 2009The discovery of a new family of high Tc materials, the iron arsenides (FeAs), has led to a resurgence of interest in superconductivity. Several important traits of these materials are now apparent, for example, layers of iron tetrahedrally coordinated ... More
Weak Completeness of Coalgebraic Dynamic LogicsSep 10 2015We present a coalgebraic generalisation of Fischer and Ladner's Propositional Dynamic Logic (PDL) and Parikh's Game Logic (GL). In earlier work, we proved a generic strong completeness result for coalgebraic dynamic logics without iteration. The coalgebraic ... More
Graded cellular basis and Jucys-Murphy elements for generalized blob algebrasDec 28 2018Jan 18 2019We give a concrete construction of a graded cellular basis for the generalized blob algebra B_n introduced by Martin and Woodcock. The construction uses the isomorphism between KLR-algebras and cyclotomic Hecke algebras, proved by Brundan-Kleshchev and ... More
On quadratic curves over finite fieldsFeb 28 2018The geometry of algebraic curves over finite fields is a rich area of research. In previous work, the authors investigated a particular aspect of the geometry over finite fields of the classical unit circle, namely how the number of solutions of the circle ... More
Hybridization of sub-gap states in one-dimensional superconductor/semiconductor Coulomb islandsApr 25 2018We present measurements of one-dimensional superconductor-semiconductor Coulomb islands, fabricated by gate confinement of a two-dimensional InAs heterostructure with an epitaxial Al layer. When tuned via electrostatic side gates to regimes without sub-gap ... More
Quantum invariants of Seifert 3-manifolds and their asymptotic expansionsOct 01 2002We report on recent results of the authors concerning calculations of quantum invariants of Seifert 3-manifolds. These results include a derivation of the Reshetikhin-Turaev invariants of all oriented Seifert manifolds associated with an arbitrary complex ... More
A universal density slope - velocity anisotropy relation for relaxed structuresNov 16 2004Sep 27 2005We identify a universal relation between the radial density slope \alpha (r) and the velocity anisotropy \beta (r) for equilibrated structures. This relation holds for a variety of systems, including disk galaxy mergers, spherical collapses, cold dark ... More
Existence of a Unique Quasi-stationary Distribution for Stochastic Reaction NetworksAug 21 2018In the setting of stochastic dynamical systems that eventually go extinct, the quasi-stationary distributions are useful to understand the long-term behavior of a system before evanescence. For a broad class of applicable continuous-time Markov processes ... More
Finite-volume effects in $(g-2)^{\text{HVP,LO}}_μ$Apr 22 2019An analytic expression is derived for the leading finite-volume effects arising in lattice QCD calculations of the hadronic-vacuum-polarization contribution to the muon's magnetic moment, $a_\mu^{\text{HVP,LO}} \equiv (g-2)_\mu^{\text{HVP,LO}}/2$. For ... More
Aggregating explainability methods for neural networks stabilizes explanationsMar 01 2019Despite a growing literature on explaining neural networks, no consensus has been reached on how to explain a neural network decision or how to evaluate an explanation. In fact, most works rely on manually assessing the explanation to evaluate the quality ... More
Sequence Modelling For Analysing Student Interaction with Educational SystemsAug 14 2017The analysis of log data generated by online educational systems is an important task for improving the systems, and furthering our knowledge of how students learn. This paper uses previously unseen log data from Edulab, the largest provider of digital ... More
Stable reconstructions in Hilbert spaces and the resolution of the Gibbs phenomenonNov 30 2010We introduce a method to reconstruct an element of a Hilbert space in terms of an arbitrary finite collection of linearly independent reconstruction vectors, given a finite number of its samples with respect to any Riesz basis. As we establish, provided ... More
Reshetikhin-Turaev invariants of Seifert 3-manifolds for classical simple Lie algebras, and their asymptotic expansionsSep 30 2002Feb 02 2003We derive formulas for the Reshetikhin-Turaev invariants of all oriented Seifert manifolds associated to an arbitrary complex finite dimensional simple Lie algebra $\mathfrak g$ in terms of the Seifert invariants and standard data for $\mathfrak g$. A ... More
Magnetoelastic effects in Jahn-Teller distorted CrF$_2$ and CuF$_2$ studied by neutron powder diffractionJun 07 2011We have studied the temperature dependence of crystal and magnetic structures of the Jahn-Teller distorted transition metal difluorides CrF$_2$ and CuF$_2$ by neutron powder diffraction in the temperature range 2-280 K. The lattice parameters and the ... More
Cell structures for the Yokonuma-Hecke algebra and the algebra of braids and tiesJun 02 2015Jun 22 2015We construct a faithful tensor representation for the Yokonuma- Hecke algebra Y, and use it to give a concrete isomorphism between Y and Shoji's modified Ariki-Koike algebra. We give a cellular basis for Y and show that the Jucys-Murphy elements for Y ... More
Observational constraints on the inflaton potential combined with flow-equations in inflaton spaceSep 26 2001Jun 28 2002Direct observations provide constraints on the first two derivatives of the inflaton potential in slow roll models. We discuss how present day observations, combined with the flow equations in slow roll parameter space, provide a non-trivial constraint ... More
Lyman Alpha Radiative Transfer in a Multi-Phase MediumJul 25 2005Hydrogen Ly-alpha is our primary emission-line window into high redshift galaxies. Surprisingly, despite an extensive literature, Ly-alpha radiative transfer in the most realistic case of a dusty, multi-phase medium has not received detailed theoretical ... More
Stationary light pulses in ultra cold atomic gassesNov 07 2006We present a theoretical treatment of electromagnetically induced transparency and light storage using standing wave coupling fields in a medium comprised of stationary atoms, such as an ultra cold atomic gas or a solid state medium. We show that it is ... More