Results for "Stuart G. Murdoch"

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Universal mechanism for the binding of temporal cavity solitonsMar 30 2017We present theoretical and experimental evidence of a universal mechanism through which temporal cavity solitons of externally-driven, passive, Kerr resonators can form robust long-range bound states. These bound states, sometime also referred to as multi-soliton ... More
Writing and Erasing of Temporal Kerr Cavity Solitons via Intensity Modulation of the Cavity Driving FieldFeb 21 2018We experimentally and numerically study the use of intensity modulation for the controlled addressing of temporal Kerr cavity solitons. Using a coherently driven fiber ring resonator, we demonstrate that a single temporally broad intensity modulation ... More
Asymmetric balance in symmetry breakingApr 15 2019Spontaneous symmetry breaking is central to our understanding of physics and explains many natural phenomena, from cosmic scales to sub-atomic particles. It can also be exploited for applications, but engineered systems naturally present some deviations ... More
Spontaneous symmetry breaking and trapping of temporal Kerr cavity solitons by pulsed or amplitude modulated driving fieldsMar 27 2018May 02 2018We report on a systematic study of temporal Kerr cavity soliton dynamics in the presence of pulsed or amplitude modulated driving fields. In stark contrast to the more extensively studied case of phase modulations, we find that Kerr cavity solitons are ... More
Origins of clustered frequency combs in Kerr microresonatorsMay 30 2018Recent experiments have demonstrated the generation of widely-spaced parametric sidebands that can evolve into "clustered" optical frequency combs in Kerr microresonators. Here we describe the physics that underpins the formation of such clustered comb ... More
Octave-spanning tunable parametric oscillation in crystalline Kerr microresonatorsApr 10 2019Parametric nonlinear optical processes allow for the generation of new wavelengths of coherent electromagnetic radiation. Their ability to create radiation that is widely tunable in wavelength is particularly appealing, with applications ranging from ... More
Real-time spectral analysis of ultrafast pulses using a free-space angular chirp enhanced delayMay 14 2019Frequency to time mapping is a powerful technique for observing ultrafast phenomena and non-repetitive events in optics. However, many optical sources operate in wavelength regions, or at power levels, that are not compatible with standard frequency to ... More
Writing and erasing of temporal cavity solitons by direct phase modulation of the cavity driving fieldJan 21 2015Temporal cavity solitons (CSs) are persisting pulses of light that can manifest themselves in continuously driven passive resonators, such as macroscopic fiber ring cavities and monolithic microresonators. Experiments so far have demonstrated two techniques ... More
Observation of dispersive wave emission by temporal cavity solitonsJun 09 2014We examine a coherently-driven, dispersion-managed, passive Kerr fiber ring resonator and report the first direct experimental observation of dispersive wave emission by temporal cavity solitons. Our observations are in excellent agreement with analytical ... More
Experimental observation of coherent cavity soliton frequency combs in silica microspheresAug 11 2016Aug 15 2016We report on the experimental observation of coherent cavity soliton frequency combs in silica microspheres. Specifically, we demonstrate that careful alignment of the microsphere relative to the coupling fiber taper allows for the suppression of higher-order ... More
Ultra-weak long-range interactions of solitons observed over astronomical distancesMay 29 2013We report what we believe is the weakest interaction between solitons ever observed. Our experiment involves temporal optical cavity solitons recirculating in a coherently-driven passive optical fibre ring resonator. We observe two solitons, separated ... More
Temporal tweezing of light: trapping and manipulation of temporal cavity solitonsOct 17 2014Optical tweezers use laser light to trap and move microscopic particles in space. Here we demonstrate a similar control over ultrashort light pulses, but in time. Our experiment involves temporal cavity solitons that are stored in a passive loop of optical ... More
Analysis of White Noise Limits for Stochastic Systems with Two Fast Relaxation TimesApr 16 2005In this paper we present a rigorous asymptotic analysis for stochastic systems with two fast relaxation times. The mathematical model analyzed in this paper consists of a Langevin equation for the particle motion with time-dependent force constructed ... More
Consistency of Quine's New Foundations using nominal techniquesJun 16 2014Jan 29 2018We build a model in nominal sets for TST+; typed set theory with typical ambiguity. It is known that this is equivalent to the consistency of Quine's New Foundations. Nominal techniques are used to constrain the size of powersets and thus model typical ... More
Homogenization for Inertial Particles in a Random FlowFeb 08 2007We study the problem of homogenization for inertial particles moving in a time dependent random velocity field and subject to molecular diffusion. We show that, under appropriate assumptions on the velocity field, the large--scale, long--time behavior ... More
Conditional Modeling and the Jitter Method of Spike Re-sampling: SupplementNov 18 2011This technical report accompanies the manuscript "Conditional Modeling and the Jitter Method of Spike Re-sampling." It contains further details, comments, references, and equations concerning various simulations and data analyses presented in that manuscript, ... More
Calculating Effective Diffusivities in the Limit of Vanishing Molecular DiffusionJun 20 2008In this paper we study the problem of the numerical calculation (by Monte Carlo Methods) of the effective diffusivity for a particle moving in a periodic divergent-free velocity filed, in the limit of vanishing molecular diffusion. In this limit traditional ... More
Widely tunable optical parametric oscillation in a Kerr microresonatorOct 03 2017We report on the first experimental demonstration of widely-tunable parametric sideband generation in a Kerr microresonator. Specifically, by pumping a silica microsphere in the normal dispersion regime, we achieve the generation of phase-matched four-wave ... More
Controlled merging and annihilation of localized dissipative structures in an AC-driven damped nonlinear Schrödinger systemApr 27 2015We report studies of controlled interactions of localized dissipative structures in a system described by the AC-driven damped nonlinear Schr\"odinger equation. Extensive numerical simulations reveal a diversity of interaction scenarios that are governed ... More
Observation of Spatiotemporal Chaos Induced by a Cavity Soliton in a Fiber Ring ResonatorFeb 11 2016We report on the experimental observation of temporal cavity soliton destabilization via spatiotemporal chaos in a coherently-driven optical fiber ring resonator. Numerical simulations and theoretical analyses are in good agreement with experimental observations. ... More
Bunching of temporal cavity solitons via forward Brillouin scatteringSep 16 2015We report on the experimental observation of bunching dynamics with temporal cavity solitons in a continuously-driven passive fibre resonator. Specifically, we excite a large number of ultrafast cavity solitons with random temporal separations, and observe ... More
Spontaneous creation and annihilation of temporal cavity solitons in a coherently-driven passive fiber resonatorMar 16 2015Mar 29 2015We report on the experimental observation of spontaneous creation and annihilation of temporal cavity solitons (CSs) in a coherently-driven, macroscopic optical fiber resonator. Specifically, we show that CSs are spontaneously created when the frequency ... More
An all-optical buffer based on temporal cavity solitons operating at 10 Gb/sJul 25 2016We demonstrate the operation of an all-optical buffer based on temporal cavity solitons stored in a nonlinear passive fiber ring resonator. Unwanted acoustic interactions between neighboring solitons are suppressed by modulating the phase of the external ... More
Coexistence and interactions between nonlinear states with different polarizations in a monochromatically driven passive Kerr resonatorFeb 14 2019We report on experimental observations of coexistence and interactions between nonlinear states with different polarizations in a passive Kerr resonator driven at a single carrier frequency. Using a fiber ring resonator with adjustable birefringence, ... More
Emission of intense resonant radiation by dispersion-managed Kerr cavity solitonsSep 20 2018We report on an experimental and numerical study of temporal Kerr cavity soliton dynamics in dispersion-managed fiber ring resonators. We find that dispersion management can significantly magnify the Kelly-like resonant radiation sidebands emitted by ... More
Experimental and numerical investigations of switching wave dynamics in a normally dispersive fiber ring resonatorFeb 28 2017Optical frequency combs generated in normally dispersive Kerr microresonators have been observed to correspond to dark temporal structures, and theoretically explained as interlocked switching waves (also known as domain walls or fronts). The time-domain ... More
Stimulated Raman Scattering Imposes Fundamental Limits to the Duration and Bandwidth of Temporal Cavity SolitonsAug 16 2017Temporal cavity solitons (CS) are optical pulses that can persist in passive resonators, and they play a key role in the generation of coherent microresonator frequency combs. In resonators made of amorphous materials, such as fused silica, they can exhibit ... More
Observations of spatiotemporal instabilities in the strong-driving regime of an AC-driven nonlinear Schrödinger systemMay 16 2016Localized dissipative structures (LDS) have been predicted to display a rich array of instabilities, yet systematic experimental studies have remained scarce. We have used a synchronously-driven optical fiber ring resonator to experimentally study LDS ... More
Measurement of microresonator frequency comb stability by spectral interferometryOct 28 2015We demonstrate a new technique for the experimental measurement of the spectral coherence of microresonator optical frequency combs. Specifically, we use a spectral interference method, typically used in the context of supercontinuum generation, to explore ... More
Nonlinear optics of fibre event horizonsMar 26 2014The nonlinear interaction of light in an optical fibre can mimic the physics at an event horizon. This analogue arises when a weak probe wave is unable to pass through an intense soliton, despite propagating at a different velocity. To date, these dynamics ... More
Patterns of Selection of Human Movements II: Movement Limits, Mechanical Energy, and Very Slow Walking GaitsOct 03 2016The biomechanics of the human body allow humans a range of possible ways of executing movements to attain specific goals. This range of movement is limited by a number of mechanical, biomechanical, or cognitive constraints. Shifts in these limits result ... More
Constructions with bundle gerbesDec 09 2003This thesis develops the theory of bundle gerbes and examines a number of useful constructions in this theory. These allow us to gain a greater insight into the structure of bundle gerbes and related objects. Furthermore they naturally lead to some interesting ... More
On the representation of Boolean and real functions as Hamiltonians for quantum computingApr 24 2018Mapping functions on bits to Hamiltonians acting on qubits has many applications in quantum computing. In particular, Hamiltonians representing Boolean functions are required for applications of quantum annealing or the quantum approximate optimization ... More
Existence and Newtonian limit of nonlinear bound states in the Einstein-Dirac systemJun 25 2009An analysis is given of particlelike nonlinear bound states in the Newtonian limit of the coupled Einstein-Dirac system introduced by Finster, Smoller and Yau. A proof is given of existence of these bound states in the almost Newtonianian regime, and ... More
Note on pre-Courant algebroid structures for parabolic geometriesSep 06 2007Mar 01 2011This note aims to demonstrate that every parabolic geometry has a naturally defined per-Courant algebro\"id structure. This structure is a Courant algebro\"id if and only if the the curvature $\kappa$ of the Cartan connection vanishes. In all other cases, ... More
Nominal Henkin Semantics: simply-typed lambda-calculus models in nominal setsNov 01 2011We investigate a class of nominal algebraic Henkin-style models for the simply typed lambda-calculus in which variables map to names in the denotation and lambda-abstraction maps to a (non-functional) name-abstraction operation. The resulting denotations ... More
Fine-Grained Decision-Theoretic Search ControlMar 27 2013Decision-theoretic control of search has previously used as its basic unit. of computation the generation and evaluation of a complete set of successors. Although this simplifies analysis, it results in some lost opportunities for pruning and satisficing. ... More
Projective Geometry I: Principles and PropertiesFeb 27 2006Mar 13 2007The aim of this paper and its sequel is to introduce and classify the holonomy algebras of the projective Tractor connection. After a brief historical background, this paper presents and analyses the projective Cartan and Tractor connections, the various ... More
Improved Moving Puncture Gauge Conditions for Compact Binary EvolutionsApr 25 2014Oct 06 2014Robust gauge conditions are critically important to the stability and accuracy of numerical relativity (NR) simulations involving compact objects. Most of the NR community use the highly robust---though decade-old---moving-puncture (MP) gauge conditions ... More
Target bias voltage effect on properties of magnetic tunnel junctions by biased target ion beam depositionJan 17 2009Magnetic tunnel junctions (MTJ) with AlOx barrier were fabricated by a deposition tool called Biased Target Ion Beam Deposition (BTIBD) using low energy ion source (0-50 eV) and voltage biased targets. The BTIBD system applies bias voltage directly and ... More
A Model of Sequential Branching in Hierarchical Cell Fate DeterminationMar 25 2009Sep 14 2009Multipotent stem or progenitor cells undergo a sequential series of binary fate decisions, which ultimately generate the diversity of differentiated cells. Efforts to understand cell fate control have focused on simple gene regulatory circuits that predict ... More
Neutrino Masses and SO(10) SUSY GUTsDec 29 2000In this talk I discuss the qualitative features of an SO(10) SUSY GUT with an SU(2)x U(1)$^n$ family symmetry. I then describe the global fit of this theory to precision electroweak data [including charged fermion masses and mixing angles]. Finally, the ... More
Synthetic Language Generation and Model Validation in BEAST2Jul 27 2016Generating synthetic languages aids in the testing and validation of future computational linguistic models and methods. This thesis extends the BEAST2 phylogenetic framework to add linguistic sequence generation under multiple models. The new plugin ... More
Ignorance is bliss: General and robust cancellation of decoherence via no-knowledge quantum feedbackJan 17 2014Jul 11 2014A "no-knowledge" measurement of an open quantum system yields no information about any system observable; it only returns noise input from the environment. Surprisingly, performing such a no-knowledge measurement can be advantageous. We prove that a system ... More
Numerical simulations of granular dynamics. I. Hard-sphere discrete element method and testsJun 11 2013We present a new particle-based (discrete element) numerical method for the simulation of granular dynamics, with application to motions of particles on small solar system body and planetary surfaces. The method employs the parallel N-body tree code pkdgrav ... More
Higher-Order Topological InsulatorsAug 11 2017Jun 03 2018Three-dimensional topological (crystalline) insulators are materials with an insulating bulk, but conducting surface states which are topologically protected by time-reversal (or spatial) symmetries. Here, we extend the notion of three-dimensional topological ... More
The gas fractions of dark matter haloes hosting simulated $\sim L^\star$ galaxies are governed by the feedback history of their black holesOct 17 2018We examine the origin of scatter in the relationship between the gas fraction and mass of dark matter haloes hosting present-day $\sim L^\star$ central galaxies in the EAGLE simulations. The scatter is uncorrelated with the accretion rate of the central ... More
Direct Detection of the Brown Dwarf GJ 802B with Adaptive Optics Masking InterferometryJul 21 2006We have used the Palomar 200" Adaptive Optics (AO) system to directly detect the astrometric brown dwarf GJ 802B reported by Pravdo et al. 2005. This observation is achieved with a novel combination of aperture masking interferometry and AO. The dynamical ... More
VO2 nanosheets: controlling the THz properties through strain engineeringDec 07 2011We investigate far-infrared properties of strain engineered vanadium dioxide nanosheets through epitaxial growth on a (100)R TiO2 substrate. The nanosheets exhibit large uniaxial strain leading to highly uniform and oriented cracks along the rutile c-axis. ... More
Asteroid Surface GeophysicsMar 06 2015The regolith-covered surfaces of asteroids preserve records of geophysical processes that have occurred both at their surfaces and sometimes also in their interiors. As a result of the unique micro-gravity environment that these bodies posses, a complex ... More
Disentangled Attribution Curves for Interpreting Random Forests and Boosted TreesMay 18 2019Tree ensembles, such as random forests and AdaBoost, are ubiquitous machine learning models known for achieving strong predictive performance across a wide variety of domains. However, this strong performance comes at the cost of interpretability (i.e. ... More
The Interplay of Topological Surface and Bulk Electronic States in Bi2Se3Oct 05 2012In this Letter we present scanning tunneling microscopy density-of-states measurements and electronic structure calculations of the topological insulator Bi2Se3. The measurements show significant background states in addition to the expected Dirac cone. ... More
Constraint Control of Nonholonomic Mechanical SystemsOct 08 2016Oct 17 2016We derive an optimal control formulation for a nonholonomic mechanical system using the nonholonomic constraint itself as the control. We focus on Suslov's problem, which is defined as the motion of a rigid body with a vanishing projection of the body ... More
Constraint Control of Nonholonomic Mechanical SystemsOct 08 2016Oct 19 2016We derive an optimal control formulation for a nonholonomic mechanical system using the nonholonomic constraint itself as the control. We focus on Suslov's problem, which is defined as the motion of a rigid body with a vanishing projection of the body ... More
Parametric Manifolds II: Intrinsic ApproachJul 12 1994A parametric manifold is a manifold on which all tensor fields depend on an additional parameter, such as time, together with a parametric structure, namely a given (parametric) 1-form field. Such a manifold admits natural generalizations of Lie differentiation, ... More
Extrapolating the Evolution of Galaxy Sizes to the Epoch of ReionizationNov 14 2010We use data on the high-redshift evolution of the size distribution and luminosity function of galaxies to constrain the relationship between their star formation efficiency and starburst lifetime. Based on the derived scaling relations, we predict the ... More
Small amplitude solitary waves in the Dirac-Maxwell systemOct 26 2012Sep 27 2017We study nonlinear bound states, or solitary waves, in the Dirac-Maxwell system proving the existence of solutions in which the Dirac wave function is of the form $\phi(x,\omega)e^{-i\omega t}$, $\omega\in(-m,\omega_*)$, with some $\omega_*>-m$, such ... More
She's Reddit: A source of statistically significant gendered interest information?Oct 13 2018Information about gender differences in interests is necessary to disentangle the effects of discrimination and choice when gender inequalities occur, such as in employment. This article assesses gender differences in interests within the popular social ... More
A Survey of Research on Control of Teams of Small Robots in Military OperationsJun 03 2016While a number of excellent review articles on military robots have appeared in existing literature, this paper focuses on a distinct sub-space of related problems: small military robots organized into moderately sized squads, operating in a ground combat ... More
Derivation and Analysis of Simplified Filters for Complex Dynamical SystemsDec 11 2015Filtering is concerned with the sequential estimation of the state, and uncertainties, of a Markovian system, given noisy observations. It is particularly difficult to achieve accurate filtering in complex dynamical systems, such as those arising in turbulence, ... More
Utility Optimization in Congested Queueing NetworksAug 26 2009Nov 24 2010We consider a multi-class single server queueing network as a model of a packet switching network. The rates packets are sent into this network are controlled by queues which act as congestion windows. By considering a sequence of congestion controls, ... More
Ambient connections realising conformal Tractor holonomyJun 16 2006For a conformal manifold we introduce the notion of an ambient connection, an affine connection on an ambient manifold of the conformal manifold, possibly with torsion, and with conditions relating it to the conformal structure. The purpose of this construction ... More
Small flow rate can supply inwardly migrating shortest-period planetsJan 17 2013The number of exoplanets found with periods as short as one day and less was surprising given how fast these planets had been expected to migrate into the star due to the tides raised on the star by planets at such close distances. It has been seen as ... More
Eclipsing Binaries in the Young LMC Cluster NGC 1850Oct 15 2004Oct 21 2004I present light curves for two detached eclipsing binary stars in the region of the LMC cluster NGC 1850, which is possibly a young globular cluster still in formation. One, a likely spectral type O star, is a newly detected eclipsing binary in the region ... More
Hot Big Planets Kepler Survey: Measuring the Repopulation Rate of the Shortest-Period PlanetsSep 12 2013By surveying new fields for the shortest-period "big" planets, the Kepler spacecraft could provide the statistics to more clearly measure the occurrence distributions of giant and medium planets. This would allow separate determinations for giant and ... More
O-cycles, vertex-oriented graphs, and the four colour theoreSep 17 2009In 1880, P. G. Tait showed that the four colour theorem is equivalent to the assertion that every 3-regular planar graph without cut-edges is 3-edge-colourable, and in 1891, J. Petersen proved that every 3-regular graph with at most two cut-edges has ... More
ChESS - Quick and Robust Detection of Chess-board FeaturesJan 23 2013Localization of chess-board vertices is a common task in computer vision, underpinning many applications, but relatively little work focusses on designing a specific feature detector that is fast, accurate and robust. In this paper the `Chess-board Extraction ... More
A note on discrete Holonomy through directed edges, with no lengthsFeb 13 2009This note demonstrates how both the concept of distance and the concept of holonomy can be constructed from a suitable network with directed edges (and no lengths). The number of different edge types depends on the signature of the metric and the dimension ... More
Hamiltonian quantization of solitons in the $φ^4_{1+1}$ quantum field theory. I. The semiclassical mass shiftApr 04 2019We study of the interaction of a scalar quantum field $\phi $ with a fixed (external) electromagnetic field $A^{ext}_\mu dx^\mu$ in two dimensional space-time. The dynamics is determined by the action functional \[ S\,=\,\int\,\Bigl(\frac{1}{2}\partial_\mu\phi\partial^\mu\phi- ... More
Effective dynamics for solitons in the nonlinear Klein Gordon Maxwell system and the Lorentz force lawMay 07 2009We consider the nonlinear Klein Gordon Maxwell system on four dimensional Minkowski space-time. For appropriate nonlinearities the system admits soliton solutions which are gauge invariant generalizations of the non-topological solitons introduced and ... More
Improving Gradient Estimation by Incorporating Sensor DataJun 13 2012An efficient policy search algorithm should estimate the local gradient of the objective function, with respect to the policy parameters, from as few trials as possible. Whereas most policy search methods estimate this gradient by observing the rewards ... More
The Shutdown Problem: How Does a Blockchain System End?Feb 19 2019We define and examine the shutdown problem for blockchain systems: how to gracefully end the system's operation at the end of its useful life. A particular focus is those blockchain systems that hold archival data of long-lived interest. We outline what ... More
The Density Matrix Renormalization Group for finite Fermi systemsApr 08 2004Dec 23 2004The Density Matrix Renormalization Group (DMRG) was introduced by Steven White in 1992 as a method for accurately describing the properties of one-dimensional quantum lattices. The method, as originally introduced, was based on the iterative inclusion ... More
Valence Bond Mapping of Antiferromagnetic Spin ChainsMar 18 1997Boson mapping techniques are developed to describe valence bond correlations in quantum spin chains. Applying the method to the alternating bond hamiltonian for a generic spin chain, we derive an analytic expression for the transition points which gives ... More
The algebra of the Catalan monoid as an incidence algebra: A simple proofJun 18 2018We give a direct straightforward proof that there is an isomorphism between the algebra of the Catalan monoid C_n that is, the monoid of all order-preserving, weakly increasing self-maps f of [n] = {1,...,n}, over any commutative ring with identity and ... More
Adaptive time-stepping for Stochastic Partial Differential Equations with non-Lipschitz driftDec 21 2018We introduce an explicit, adaptive time-stepping scheme for simulation of SPDEs with non-Lipschitz drift coefficients. Strong convergence is proven for the full space-time discretisation with multiplicative noise by considering the space and time discretisation ... More
Nekhoroshev type stability results for Hamiltonian systems with an additional transversal componentNov 18 2011Jan 18 2012We prove exponential stability theorems of Nekhoroshev type for motion in the neighbourhood of an elliptic fixed point in Hamiltonian systems having an additional transverse component of arbitrary dimension.
The Maximal Graph Dirichlet Problem in Semi-Euclidean SpacesDec 19 2011The maximal graph Dirichlet problem asks whether there exists a spacelike graph, in a semi-Euclidean space, with a given boundary and with mean curvature everywhere zero. We prove the existence of solutions to this problem under certain assumptions on ... More
Interplay between intermittency and dissipation in collisionless plasma turbulenceJul 24 2018Apr 15 2019We study the damping of collisionless Alfv\'enic turbulence by two mechanisms: stochastic heating (whose efficiency depends on the local turbulence amplitude $\delta z_\lambda$) and linear Landau damping (whose efficiency is independent of $\delta z_\lambda$), ... More
Courant Algebroids in Parabolic GeometryDec 29 2011Sep 23 2012Let $p$ be a Lie subalgebra of a semisimple Lie algebra $g$ and $(G,P)$ be the corresponding pair of connected Lie groups. A Cartan geometry of type $(G,P)$ associates to a smooth manifold $M$ a principal $P$-bundle and a Cartan connection, and a parabolic ... More
Talking about interaction*Mar 08 2019Recent research has exposed disagreements over the nature and usefulness of what may (or may not) be Human-Computer Interaction's fundamental phenomenon: 'interaction'. For some, HCI's theorising about interaction has been deficient, impacting its capacity ... More
Using Simulated Annealing to Calculate the Trembles of Trembling Hand PerfectionSep 10 2003Within the literature on non-cooperative game theory, there have been a number of attempts to propose logorithms which will compute Nash equilibria. Rather than derive a new algorithm, this paper shows that the family of algorithms known as Markov chain ... More
Finding Traitors in Secure Networks Using Byzantine AgreementsAug 19 2003Feb 05 2006Secure networks rely upon players to maintain security and reliability. However not every player can be assumed to have total loyalty and one must use methods to uncover traitors in such networks. We use the original concept of the Byzantine Generals ... More
A temporally abstracted Viterbi algorithmFeb 14 2012Hierarchical problem abstraction, when applicable, may offer exponential reductions in computational complexity. Previous work on coarse-to-fine dynamic programming (CFDP) has demonstrated this possibility using state abstraction to speed up the Viterbi ... More
Iron abundance correlations and an occurrence distribution discrepancy from ongoing planet migrationMay 22 2013Sep 12 2013Whether the higher occurrence of giant planets being hosted by metal-rich versus metal-poor stars results from formation or from "pollution" has been a question of intense debate. We present new patterns that emerge when planet/star systems are separated ... More
Observing the Luminosity Increase and Roche Lobe Overflow of Planet DestructionSep 21 2010The destruction of planets by migration into the star will release significant amounts of energy and material, which will present opportunities to observational study planets in new ways. To observe planet destruction, it is important to understand the ... More
Cartan subalgebras in uniform Roe algebrasAug 13 2018In this paper we study structural and uniqueness questions for Cartan subalgebras of uniform Roe algebras. We characterise when an inclusion $B\subseteq A$ of $\mathrm{C}^*$-algebras is isomorphic to the canonical inclusion of $\ell^\infty(X)$ inside ... More
On the dimension and measure of inhomogeneous attractorsMay 02 2018Sep 10 2018A central question in the field of inhomogeneous attractors has been to relate the dimension of an inhomogeneous attractor to the condensation set and associated homogeneous attractor. This has been achieved only in specific settings, with notable results ... More
Sieved Enumeration of Interval Orders and Other Fishburn StructuresFeb 18 2015Mar 10 2015Following a result of Eriksen and Sj\"{o}strand (2014) we detail a technique to construct structures following the Fishburn distribution from appropriate Mahonian structures. This technique is introduced on a bivincular pattern of Bousquet-M\'elou et ... More
Interplay between intermittency and dissipation in collisionless plasma turbulenceJul 24 2018We study the damping of collisionless Alfv\'enic turbulence by two mechanisms: stochastic heating (whose efficiency depends on the local turbulence amplitude $\delta z_\lambda$) and linear Landau damping (whose efficiency is independent of $\delta z_\lambda$), ... More
Super cavity solitons and the coexistence of multiple nonlinear states in a tristable passive Kerr resonatorFeb 02 2017Passive Kerr cavities driven by coherent laser fields display a rich landscape of nonlinear physics, including bistability, pattern formation, and localised dissipative structures (solitons). Their conceptual simplicity has for several decades offered ... More
The self-injection threshold in self-guided laser wakefield acceleratorsJan 05 2012A laser pulse traveling through a plasma can excite large amplitude plasma waves that can be used to accelerate relativistic electron beams in a very short distance---a technique called laser wakefield acceleration. Many wakefield acceleration experiments ... More
A chronicle of galaxy mass assembly in the EAGLE simulationSep 23 2016We analyse the mass assembly of central galaxies in the EAGLE hydrodynamical simulations. We build merger trees to connect galaxies to their progenitors at different redshifts and characterize their assembly histories by focusing on the time when half ... More
An Alternative Conception of Tree-Adjoining DerivationApr 04 1994The precise formulation of derivation for tree-adjoining grammars has important ramifications for a wide variety of uses of the formalism, from syntactic analysis to semantic interpretation and statistical language modeling. We argue that the definition ... More
Inverse Compton Scattering as the Source of Diffuse EUV Emission in the Coma Cluster of GalaxiesApr 28 1998We have examined the hypothesis that the majority of the diffuse EUV flux in the Coma cluster is due to inverse Compton scattering of low energy cosmic ray electrons (0.16 < epsilon < 0.31 GeV) against the 3K black-body background. We present data on ... More
Enhancement of AGN in a protocluster at z=1.6May 30 2017We investigate the prevalence of AGN in the high-redshift protocluster $\rm{Cl}\,0218.3$-$0510$ at $z=1.62$. Using imaging from the Chandra X-ray Telescope, we find a large overdensity of AGN in the protocluster; a factor of $23\pm9$ times the field density ... More
Masses of Astrometrically-Discovered and Imaged Binaries: G 78-28AB and GJ 231.1BCMay 11 2006The Stellar Planet Survey (STEPS) is an ongoing astrometric search for giant planets and brown dwarfs around a sample of ~30 M-dwarfs. We have discovered several low-mass companions by measuring the motion of our target stars relative to their reference ... More
Interactions between Coronal Mass Ejections Viewed in Coordinated Imaging and In Situ ObservationsJan 13 2012The successive coronal mass ejections (CMEs) from 2010 July 30 - August 1 present us the first opportunity to study CME-CME interactions with unprecedented heliospheric imaging and in situ observations from multiple vantage points. We describe two cases ... More
Pressure-induced superconductivity and topological quantum phase transitions in a quasi-one-dimensional topological insulator: Bi4I4Jan 30 2017Superconductivity and topological quantum states are two frontier fields of research in modern condensed matter physics. The realization of superconductivity in topological materials is highly desired, however, superconductivity in such materials is typically ... More