Results for "David Griffiths"

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SynthCity: A large scale synthetic point cloudJul 10 2019With deep learning becoming a more prominent approach for automatic classification of three-dimensional point cloud data, a key bottleneck is the amount of high quality training data, especially when compared to that available for two-dimensional images. ... More
A review on deep learning techniques for 3D sensed data classificationJul 09 2019Over the past decade deep learning has driven progress in 2D image understanding. Despite these advancements, techniques for automatic 3D sensed data understanding, such as point clouds, is comparatively immature. However, with a range of important applications ... More
At most 27 length inequalities define Maskit's fundamental domain for the modular group in genus 2Nov 09 1998In recently published work Maskit constructs a fundamental domain D_g for the Teichmueller modular group of a closed surface S of genus g>1. Maskit's technique is to demand that a certain set of 2g non-dividing geodesics C_{2g} on S satisfies certain ... More
Decoupling between electric and thermal conduction in low dimensional systemsMar 14 2019Mar 20 2019We studied the thermal conduction in a system comprising two widely separated 1D channels by monitoring the thermo-voltage built between the two channels. We find the position of thermo-voltage peak follows a cubic trend against applied transverse magnetic ... More
Weighted Point Cloud Augmentation for Neural Network Training Data Class-ImblanceApr 08 2019Recent developments in the field of deep learning for 3D data have demonstrated promising potential for end-to-end learning directly from point clouds. However, many real-world point clouds contain a large class im-balance due to the natural class im-balance ... More
Weighted Point Cloud Augmentation for Neural Network Training Data Class-ImbalanceApr 08 2019Apr 09 2019Recent developments in the field of deep learning for 3D data have demonstrated promising potential for end-to-end learning directly from point clouds. However, many real-world point clouds contain a large class im-balance due to the natural class im-balance ... More
Cognitive Model Priors for Predicting Human DecisionsMay 22 2019Human decision-making underlies all economic behavior. For the past four decades, human decision-making under uncertainty has continued to be explained by theoretical models based on prospect theory, a framework that was awarded the Nobel Prize in Economic ... More
Lancaster distributions and Markov chains with Multivariate Poisson-Charlier, Meixner and Hermite-Chebycheff polynomial eigenfunctionsDec 12 2014Dec 18 2015This paper studies new Lancaster characterizations of bivariate multivariate Poisson, negative binomial and normal distributions which have diagonal expansions in multivariate orthogonal polynomials. The characterizations extend classical Lancaster characterizations ... More
What's the Use of Bound Charge?Jun 08 2015Sep 20 2015Bound charge is a useful construct for calculating the electrostatic field of polarized material, and it represents a perfectly genuine accumulation of charge. But is such a material in every respect equivalent to a particular configuration of bound charge? ... More
Glyph Sorting: Interactive Visualization for Multi-dimensional DataApr 10 2013Glyph-based visualization is an effective tool for depicting multivariate information. Since sorting is one of the most common analytical tasks performed on individual attributes of a multi-dimensional data set, this motivates the hypothesis that introducing ... More
Mansuripur's ParadoxMar 04 2013Jul 02 2013A recent article claims that the Lorentz force law is incompatible with special relativity. We discuss the "paradox" on which this claim is based. The resolution depends on whether one assumes a "Gilbert" model for the magnetic dipole (separated monopoles) ... More
The Fields of a Charged Particle in Hyperbolic MotionMay 29 2014A particle in hyperbolic motion produces electric fields that appear to terminate in mid-air, violating Gauss's law. The resolution to this paradox has been known for sixty years, but exactly why the naive approach fails is not so clear.
The torque on a dipole in uniform motionAug 21 2013Jan 18 2014We calculate the torque on an ideal (point) dipole moving with constant velocity through uniform electric and magnetic fields.
Adaptive Sensor Placement for Continuous SpacesMay 16 2019We consider the problem of adaptively placing sensors along an interval to detect stochastically-generated events. We present a new formulation of the problem as a continuum-armed bandit problem with feedback in the form of partial observations of realisations ... More
Long time behavior of solutions to the mKdVJul 05 2014Oct 09 2015In this paper we consider the long time behavior of solutions to the modified Korteweg-de Vries equation on R. For sufficiently small, smooth, decaying data we prove global existence and derive modified asymptotics without relying on complete integrability. ... More
Modelling Levy space-time white noisesJul 09 2019Based on the theory of independently scattered random measures, we introduce a natural generalisation of Gaussian space-time white noise to a Levy-type setting, which we call Levy-valued random measures. We determine the subclass of cylindrical Levy processes ... More
Reply to Comment [axXiv:1610.07734] by L. Vaidman on "Particle path through a nested Mach-Zehnder interferometer" [R. B. Griffiths, Phys. Rev. A 94 (2016) 032115]Apr 10 2017The correctness of the consistent histories analysis of weakly interacting probes, related to the path of a particle, is maintained against the criticisms in the Comment, and against the alternative approach described there, which receives no support ... More
Syzygy Theorems via Comparison of Order Ideals on a HypersurfaceJun 18 2011We introduce a weak order ideal property that suffices for establishing the Evans-Griffith Syzygy Theorem. We study this weak order ideal property in settings that allow for comparison between homological algebra over a local ring $R$ versus a hypersurface ... More
Incorporating Inductances in Tissue-Scale Models of Cardiac ElectrophysiologyJun 26 2017Aug 17 2017In standard models of cardiac electrophysiology, including the bidomain and monodomain models, local perturbations can propagate at infinite speed. We address this unrealistic property by developing a hyperbolic bidomain model that is based on a generalization ... More
Single-photon Emission from an Acoustically-driven Lateral Light-emitting DiodeJan 11 2019Single-photon sources are essential building blocks in quantum photonic networks, where quantum-mechanical properties of photons are utilised to achieve quantum technologies such as quantum cryptography and quantum computing. Most conventional solid-state ... More
The nested Chinese restaurant process and Bayesian nonparametric inference of topic hierarchiesOct 03 2007Aug 27 2009We present the nested Chinese restaurant process (nCRP), a stochastic process which assigns probability distributions to infinitely-deep, infinitely-branching trees. We show how this stochastic process can be used as a prior distribution in a Bayesian ... More
Representational efficiency outweighs action efficiency in human program inductionJul 18 2018The importance of hierarchically structured representations for tractable planning has long been acknowledged. However, the questions of how people discover such abstractions and how to define a set of optimal abstractions remain open. This problem has ... More
Reconfigurable ASIC for a Low Level Trigger System in Cherenkov Telescope CamerasNov 29 2016A versatile and reconfigurable ASIC is presented, which implements two different concepts of low level trigger (L0) for Cherenkov telescopes: the Majority trigger (sum of discriminated inputs) and the Sum trigger concept (analogue clipped sum of inputs). ... More
Dual-functional Radar-Communication Waveform Design under Constant-modulus and Orthogonality ConstraintsApr 11 2019In this paper, we focus on constant-modulus waveform design for the dual use of radar target detection and cellular transmission. As the MIMO radar typically transmits orthogonal waveforms to search potential targets, we aim at jointly minimizing the ... More
Thermodynamic Limit for Dipolar MediaDec 15 2000We prove existence of a shape and boundary condition independent thermodynamic limit for fluids and solids of identical particles with electric or magnetic dipole moments. Our result applies to fluids of hard core particles, to dipolar soft spheres and ... More
The Optional Prisoner's Dilemma in a Spatial Environment: Coevolving Game Strategy and Link WeightsSep 19 2016In this paper, the Optional Prisoner's Dilemma game in a spatial environment, with coevolutionary rules for both the strategy and network links between agents, is studied. Using a Monte Carlo simulation approach, a number of experiments are performed ... More
Moderate deviations of subgraph counts in the Erdős-Rényi random graphs $G(n,m)$ and $G(n,p)$Feb 18 2019The main contribution of this article is an asymptotic expression for the rate associated with moderate deviations of subgraph counts in the Erd\H{o}s-R\'enyi random graph $G(n,m)$. Our approach is based on applying Freedman's inequalities for the probability ... More
CMB Constraints on a Baryonic Dark Matter-Dominated UniverseJan 23 2001Mar 30 2001In recent years, upper limits on the cosmic microwave background (CMB) anisotropies combined with predictions made by theories of galaxy formation, have been extremely powerful in ruling out purely baryonic dark matter (BDM) universes. However, it has ... More
Constrained Bayesian Optimization for Automatic Chemical DesignSep 16 2017Jun 27 2018Automatic Chemical Design provides a framework for generating novel molecules with optimized molecular properties. The current model suffers from the pathology that it tends to produce invalid molecular structures. By reformulating the search procedure ... More
The Impact of Coevolution and Abstention on the Emergence of CooperationApr 28 2017This paper explores the Coevolutionary Optional Prisoner's Dilemma (COPD) game, which is a simple model to coevolve game strategy and link weights of agents playing the Optional Prisoner's Dilemma game. We consider a population of agents placed in a lattice ... More
Galois scaffolds and Galois module structure in extensions of characteristic $p$ local fields of degree $p^2$Jun 17 2011A Galois scaffold, in a Galois extension of local fields with perfect residue fields, is an adaptation of the normal basis to the valuation of the extension field, and thus can be applied to answer questions of Galois module structure. Here we give a ... More
Densest versus jammed packings of bent-core trimersJun 28 2019We identify putatively maximally dense packings of tangent-sphere trimers with fixed bond angles ($\theta = \theta_0$) using a novel method, and contrast them to the disordered jammed states they form under quasistatic and dynamic athermal compression. ... More
Cyclic Dominance in the Spatial Coevolutionary Optional Prisoner's Dilemma GameFeb 09 2017This paper studies scenarios of cyclic dominance in a coevolutionary spatial model in which game strategies and links between agents adaptively evolve over time. The Optional Prisoner's Dilemma (OPD) game is employed. The OPD is an extended version of ... More
Extremal degenerations of polarized Hodge structuresMar 04 2014Apr 29 2014We describe a Hodge theoretic approach to the question: In what ways can a smooth projective variety degenerate?
Constraints on the distance to SGR 1806-20 from HI absorptionMar 08 2005Aug 04 2005The giant flare detected from the magnetar SGR 1806-20 on 2004 December 27 had a fluence more than 100 times higher than the only two other SGR flares ever recorded. Whereas the fluence is independent of distance, an estimate for the luminosity of the ... More
Symmetric Rendezvous With Advice: How to Rendezvous in a DiskMay 09 2018In the classic Symmetric Rendezvous problem on a Line (SRL), two robots at known distance 2 but unknown direction execute the same randomized algorithm trying to minimize the expected rendezvous time. A long standing conjecture is that the best possible ... More
On the necessity of new ramification breaksApr 30 2007Ramification invariants are necessary, but not in general sufficient, to determine the Galois module structure of ideals in local number field extensions. This insufficiency is associated with elementary abelian extensions, where one can define a refined ... More
Sufficient Conditions for Large Galois ScaffoldsAug 09 2013Jul 19 2017Let $L/K$ be a finite Galois, totally ramified $p$-extension of complete local fields with perfect residue fields of characteristic $p>0$. In this paper, we give conditions, valid for any Galois $p$-group $G={Gal}(L/K)$ (abelian or not) and for $K$ of ... More
A valuation criterion for normal bases in elementary abelian extensionsApr 29 2006Nov 19 2006Let $p$ be a prime number and let $K$ be a finite extension of the field $\mathbb{Q}_p$ of $p$-adic numbers. Let $N$ be a fully ramified, elementary abelian extension of $K$. Under a mild hypothesis on the extension $N/K$, we show that every element of ... More
Finite depth gravity water waves in holomorphic coordinatesJul 08 2016Jul 11 2016In this article we consider irrotational gravity water waves with finite bottom. Our goal is two-fold. First, we represent the equations in holomorphic coordinates and discuss the local well-posedness of the problem in this context. Second, we consider ... More
A Further Analysis of The Role of Heterogeneity in Coevolutionary Spatial GamesNov 09 2017Heterogeneity has been studied as one of the most common explanations of the puzzle of cooperation in social dilemmas. A large number of papers have been published discussing the effects of increasing heterogeneity in structured populations of agents, ... More
Quotients of non-classical flag domains are not algebraicMar 01 2013A flag domain D = G/V for G a simple real non-compact group G with compact Cartan subgroup is non-classical if it does not fiber holomorphically or anti-holomorphically over a Hermitian symmetric space. We prove that any two points in a non-classical ... More
Constraining Exoplanet Metallicities and Aerosols with ARIEL: An Independent Study by the Contribution to ARIEL Spectroscopy of Exoplanets (CASE) TeamJun 06 2019Launching in 2028, ESA's Atmospheric Remote-sensing Exoplanet Large-survey (ARIEL) survey of $\sim$1000 transiting exoplanets will build on the legacies of Kepler and TESS and complement JWST by placing its high precision exoplanet observations into a ... More
Formalizing Neurath's Ship: Approximate Algorithms for Online Causal LearningSep 14 2016Higher-level cognition depends on the ability to learn models of the world. We can characterize this at the computational level as a structure-learning problem with the goal of best identifying the prevailing causal relationships among a set of relata. ... More
Formalizing Neurath's Ship: Approximate Algorithms for Online Causal LearningSep 14 2016May 26 2017Higher-level cognition depends on the ability to learn models of the world. We can characterize this at the computational level as a structure-learning problem with the goal of best identifying the prevailing causal relationships among a set of relata. ... More
Evidence for additional thermal conduction modes in low dimensional systemMar 14 2019Mar 15 2019We studies the thermal conduction in a system comprising two widely separated 1D channel by monitoring the thermo-voltage built between the two channel. We find the position of thermo-voltage peak follows a cubic trend against applied transverse magnetic ... More
ScotGrid: Providing an Effective Distributed Tier-2 in the LHC EraOct 23 2009ScotGrid is a distributed Tier-2 centre in the UK with sites in Durham, Edinburgh and Glasgow. ScotGrid has undergone a huge expansion in hardware in anticipation of the LHC and now provides more than 4MSI2K and 500TB to the LHC VOs. Scaling up to this ... More
Interference Effects in a Tunable Quantum Point Contact Integrated with an Electronic CavityAug 17 2017We show experimentally how quantum interference can be produced using an integrated quantum system comprising an arch-shaped short quantum wire (or quantum point contact, QPC) of 1D electrons and a reflector forming an electronic cavity. On tuning the ... More
Evidence for additional thermal conduction modes in low dimensional systemMar 14 2019We studies the thermal conduction in a system comprising two widely separated 1D channel by monitoring the thermo-voltage built between the two channel. We find the position of thermo-voltage peak follows a cubic trend against applied transverse magnetic ... More
Recent Progress on Developments and Characterization of Hybrid CMOS X-ray DetectorsJul 25 2012Future space-based X-ray telescope missions are likely to have significantly increased demands on detector read out rates due to increased collection area, and there will be a desire to minimize radiation damage in the interests of maintaining spectral ... More
The speedster-EXD - A new event-triggered hybrid CMOS x-ray detectorNov 17 2014We present preliminary characterization of the Speedster-EXD, a new event driven hybrid CMOS detector (HCD) developed in collaboration with Penn State University and Teledyne Imaging Systems. HCDs have advantages over CCDs including lower susceptibility ... More
An Immersed Boundary Method with Divergence-Free Velocity Interpolation and Force SpreadingJan 25 2017Jun 15 2017The Immersed Boundary (IB) method is a mathematical framework for constructing robust numerical methods to study fluid-structure interaction in problems involving an elastic structure immersed in a viscous fluid. The IB formulation uses an Eulerian representation ... More
Characterization of Si Hybrid CMOS Detectors for use in the Soft X-ray BandMar 26 2013We report on the characterization of four Teledyne Imaging Systems HAWAII Hybrid Si CMOS detectors designed for X-ray detection. Three H1RG detectors were studied along with a specially configured H2RG. Read noise measurements were performed, with the ... More
Characterization of an x-ray hybrid CMOS detector with low interpixel capacitive crosstalkJul 26 2012We present the results of x-ray measurements on a hybrid CMOS detector that uses a H2RG ROIC and a unique bonding structure. The silicon absorber array has a 36{\mu}m pixel size, and the readout array has a pitch of 18{\mu}m; but only one readout circuit ... More
The Speedster-EXD- A New Event-Driven Hybrid CMOS X-ray DetectorFeb 24 2016The Speedster-EXD is a new 64x64 pixel, 40 $\mu$m pixel pitch, 100 $\mu$m depletion depth hybrid CMOS X-ray detector (HCD) with the capability of reading out only those pixels containing event charge, thus enabling fast effective frame rates. A global ... More
The Ramsey number of the clique and the hypercubeJun 03 2013The Ramsey number r(K_s,Q_n) is the smallest positive integer N such that every red-blue colouring of the edges of the complete graph K_N on N vertices contains either a red n-dimensional hypercube, or a blue clique on s vertices. Answering a question ... More
On the Ramsey number of the triangle and the cubeFeb 15 2013The Ramsey number r(K_3,Q_n) is the smallest integer N such that every red-blue colouring of the edges of the complete graph K_N contains either a red n-dimensional hypercube, or a blue triangle. Almost thirty years ago, Burr and Erd\H{o}s conjectured ... More
Incipient singlet-triplet states in a hybrid mesoscopic systemJun 28 2018In the present work we provide an easily accessible way to achieve the singlet-triplet Kondo effect in a hybrid system consisting of a quantum point contact (QPC) coupled to an electronic cavity. We show that by activating the coupling between the QPC ... More
Fano Resonance in a cavity-reflector hybrid systemFeb 08 2017We present the results of transport measurements in a hybrid system consisting of an arch-shaped quantum point contact (QPC) and a reflector; together, they form an electronic cavity in between them. On tuning the arch-QPC and the reflector, asymmetric ... More
Multiwavelength Properties of the X-ray Sources in the Groth-Westphal Strip FieldFeb 26 2004We summarize the multiwavelength properties of X-ray sources detected in the 80 ks XMM-Newton observation of the Groth-Westphal Strip. We find 23 XMM-Newton sources within the WFPC2 fields. Ten spectroscopic redshifts are available from the DEEP and CFRS ... More
Chandra ACIS-S Observations of Three Quasars with Low-Redshift Damped Ly-alpha Absorption: Constraints on the Cosmic Neutral-Gas-Phase Metallicity at Redshift z \approx 0.4Feb 26 2003Chandra X-Ray Observatory (CXO) ACIS-S spectra of three quasars which lie behind three foreground damped Lyman alpha (DLA) absorbers are analyzed in order to attempt to determine the amount of photoelectric absorption due to metals present in their x-ray ... More
Temperature Dependence of Spin-Split Peaks in Transverse Electron FocusingSep 22 2017We present experimental results of transverse electron-focusing measurements performed using n-type GaAs. In the presence of a small transverse magnetic field (B), electrons are focused from the injector to detector leading to focusing peaks periodic ... More
Modularizing Contexted ConstraintsJun 08 1996This paper describes a method for compiling a constraint-based grammar into a potentially more efficient form for processing. This method takes dependent disjunctions within a constraint formula and factors them into non-interacting groups whenever possible ... More
Quasi-random oriented graphsJan 28 2011Aug 10 2011We show that a number of conditions on oriented graphs, all of which are satisfied with high probability by randomly oriented graphs, are equivalent. These equivalences are similar to those given by Chung, Graham and Wilson in the case of unoriented graphs, ... More
Cooperation in the spatial prisoner's dilemma game with probabilistic abstentionNov 25 2018Dec 10 2018Research has shown that the addition of abstention as an option transforms social dilemmas to rock-paper-scissor type games, where defectors dominate cooperators, cooperators dominate abstainers (loners), and abstainers (loners), in turn, dominate defectors. ... More
Evaluating computational models of explanation using human judgmentsSep 26 2013We evaluate four computational models of explanation in Bayesian networks by comparing model predictions to human judgments. In two experiments, we present human participants with causal structures for which the models make divergent predictions and either ... More
Finite Size Effects in Topological Quantum Phase TransitionsMar 02 2019The interest in the topological properties of materials brings into question the problem of topological phase transitions. As a control parameter is varied, one may drive a system through phases with different topological properties. What is the nature ... More
Evidence for a high energy curvature in the XMM-Newton spectrum of the ULX NGC1313 X-1Nov 03 2005ASCA X-ray spectra of many ULXs were described in terms of optically thick emission from hot (kT ~1-2keV) accretion disks, while recent XMM-Newton and Chandra observations have revealed a cool (kT ~0.2keV), soft X-ray excess emission from a number of ... More
Multivariate Krawtchouk polynomials and composition birth and death processesMar 01 2016May 03 2016This paper defines the multivariate Krawtchouk polynomials, orthogonal on the multinomial distribution, and summarizes their properties as a review. The multivariate Krawtchouk polynomials are symmetric functions of orthogonal sets of functions defined ... More
Asymptotically tight bounds on subset sumsMay 31 2008For a subset A of a finite abelian group G we define Sigma(A)={sum_{a\in B}a:B\subset A}. In the case that Sigma(A) has trivial stabiliser, one may deduce that the size of Sigma(A) is at least quadratic in |A|; the bound |Sigma(A)|>= |A|^{2}/64 has recently ... More
Bosonic Dirac Materials on a honeycomb antiferromagnetic Ising modelApr 12 2019Motivated by the recent proposal of Bosonic Dirac materials (BDM), we revisited the Ising model on a honeycomb lattice in the presence of the longitudinal and transverse fields. We apply linear spin-wave theory to obtain the magnon dispersion and its ... More
Solution landscapes in nematic microfluidicsJul 18 2016We study the static equilibria of a simplified Leslie--Ericksen model for a unidirectional uniaxial nematic flow in a prototype microfluidic channel, as a function of the pressure gradient $\mathcal{G}$ and inverse anchoring strength, $\mathcal{B}$. We ... More
Truth and memory: Linking instantaneous and retrospective self-reported cigarette consumptionJan 11 2013Studies of smoking behavior commonly use the time-line follow-back (TLFB) method, or periodic retrospective recall, to gather data on daily cigarette consumption. TLFB is considered adequate for identifying periods of abstinence and lapse but not for ... More
Simulation of an Optional Strategy in the Prisoner's Dilemma in Spatial and Non-spatial EnvironmentsAug 17 2016This paper presents research comparing the effects of different environments on the outcome of an extended Prisoner's Dilemma, in which agents have the option to abstain from playing the game. We consider three different pure strategies: cooperation, ... More
Mobility restores the mechanism which supports cooperation in the voluntary prisoner's dilemma gameJul 11 2019It is generally believed that in a situation where individual and collective interests are in conflict, the availability of optional participation is a key mechanism to maintain cooperation. Surprisingly, this effect is sensitive to the use of microscopic ... More
Cycles over fields of transcendence degree oneNov 18 2002Jul 11 2003We extend earlier examples provided by Schoen, Nori and Bloch to show that when a surface has the property that the kernel of its Albanese map is non-zero over the field of complex numbers, this kernel is non-zero over a field of transcendence degree ... More
Quantifying synergistic information remains an unsolved problemDec 07 2011May 22 2012This paper has been withdrawn by the author. This paper is now obsolete. For a solution please see: arXiv:/1205.4265.
One way cuts in oriented graphsDec 28 2007Nov 19 2010This paper has been withdrawn by the author.
(k+1)-sums versus k-sumsNov 19 2010Jun 08 2012A $k$-sum of a set $A\subseteq \mathbb{Z}$ is an integer that may be expressed as a sum of $k$ distinct elements of $A$. How large can the ratio of the number of $(k+1)$-sums to the number of $k$-sums be? Writing $k\wedge A$ for the set of $k$-sums of ... More
Evaluating vector-space models of analogyMay 12 2017Jun 08 2017Vector-space representations provide geometric tools for reasoning about the similarity of a set of objects and their relationships. Recent machine learning methods for deriving vector-space embeddings of words (e.g., word2vec) have achieved considerable ... More
Quasi Periodic Oscillations and Strongly Comptonized X-ray emission from Holmberg IX X-1Feb 21 2006Feb 21 2006We report the discovery of a 200mHz quasi-periodic oscillation (QPO) in the X-ray emission from a bright ultra-luminous X-ray source (ULX) Holmberg IX X-1 using a long XMM-Newton observation. The QPO has a centroid at 202.5_{-3.8}^{+4.9}mHz, a coherence ... More
Tight inequalities among set hitting times in Markov chainsSep 01 2012Sep 28 2012Given an irreducible discrete-time Markov chain on a finite state space, we consider the largest expected hitting time $T(\alpha)$ of a set of stationary measure at least $\alpha$ for $\alpha\in(0,1)$. We obtain tight inequalities among the values of ... More
A panoramic view of the Milky Way HI gasOct 30 2009Imaging of galaxies to study the interstellar medium on scales of a few pc is difficult. However, for the Milky Way galaxy two major Galactic all sky HI 21-cm line surveys will become available soon with unprecedented quality. We present the Galactic ... More
Interfacial deformation and jetting of a magnetic fluidJan 05 2015An attractive technique for forming and collecting aggregates of magnetic material at a liquid--air interface by an applied magnetic field gradient was recently addressed theoretically and experimentally [Soft Matter, (9) 2013, 8600-8608]: when the magnetic ... More
A Principled Infotheoretic φ-like MeasureJan 06 2014Oct 09 2014Integrated information theory is a mathematical, quantifiable theory of conscious experience. The linchpin of this theory, the $\phi$ measure, quantifies a system's irreducibility to disjoint parts. Purely as a measure of irreducibility, we pinpoint three ... More
Scaffolds and Generalized Integral Galois Module StructureAug 09 2013Jul 25 2017Let $L/K$ be a finite, totally ramified $p$-extension of complete local fields with residue fields of characteristic $p > 0$, and let $A$ be a $K$-algebra acting on $L$. We define the concept of an $A$-scaffold on $L$, thereby extending and refining the ... More
Evoplex: A platform for agent-based modeling on networksNov 25 2018Mar 12 2019Agent-based modeling and network science have been used extensively to advance our understanding of emergent collective behavior in systems that are composed of a large number of simple interacting individuals or agents. With the increasing availability ... More
Completion of Period Mappings and Ampleness of the Hodge bundleAug 31 2017Let $M\subset \Gamma\backslash D$ be the image of a period map. We construct a canonical completion $\overline{M}$ of $M$ as a compact complex analytic variety. We then prove that the augmented Hodge line bundle $\hat\Lambda$ extends to an ample line ... More
On-chip single photon emission from an integrated semiconductor quantum dot into a photonic crystal waveguideJan 17 2012We demonstrate the in-plane emission of highly-polarized single photons from an InAs quantum dot embedded into a photonic crystal waveguide. The spontaneous emission rates are Purcell-enhanced by the coupling of the quantum dot to a slow-light mode of ... More
Coherent Spin Amplification Using a Beam SplitterMar 27 2018We report spin amplification using a capacitive beam splitter in n-type GaAs where the spin polarization is monitored via transverse electron focusing measurement. It is shown that partially spin-polarized current injected by the emitter can be precisely ... More
Magnetoresistance in an electronic cavity coupled to one-dimensional systemsSep 10 2018In this work, we performed magnetoresistance measurement in a hybrid system consisting of an arc-shaped quantum point contact (QPC) and a flat, rectangular QPC, both of which together form an electronic cavity between them. The results highlight a transition ... More
Quantifying synergistic mutual informationMay 18 2012Mar 31 2014Quantifying cooperation or synergy among random variables in predicting a single target random variable is an important problem in many complex systems. We review three prior information-theoretic measures of synergy and introduce a novel synergy measure ... More
Irreducibility is Minimum Synergy Among PartsNov 28 2013Dec 12 2013For readers already familiar with Partial Information Decomposition (PID), we show that PID's definition of synergy enables quantifying at least four different notions of irreducibility. First, we show four common notions of "parts" give rise to a spectrum ... More
Channel kets, entangled states, and the location of quantum informationSep 16 2004May 26 2005The well-known duality relating entangled states and noisy quantum channels is expressed in terms of a channel ket, a pure state on a suitable tripartite system, which functions as a pre-probability allowing the calculation of statistical correlations ... More
The Nature and Location of Quantum InformationMar 13 2002Quantum information is defined by applying the concepts of ordinary (Shannon) information theory to a quantum sample space consisting of a single framework or consistent family. A classical analogy for a spin-half particle and other arguments show that ... More
Hard X-ray Variability in M82: Evidence for a Nascent AGN?Mar 24 1999We report on the detection of hard (2-10 keV) X-ray variability in the starburst galaxy M82 over the course of 9 ASCA observations. Long-term variability occurred on a time scale of days, with a change in flux by a factor of up to 4, corresponding to ... More
The star-shaped Lambda-coalescent and Fleming-Viot processJun 24 2015May 08 2016The star-shaped $\Lambda$-coalescent and corresponding $\Lambda$-Fleming-Viot process where the $\Lambda$ measure has a single atom at unity are studied in this paper. The transition functions and stationary distribution of the $\Lambda$-Fleming-Viot ... More
Nonexistence of Quantum NonlocalityApr 16 2013What violations of Bell inequalities teach us is that the world is quantum mechanical, i.e., nonclassical. Assertions that they imply the world is nonlocal arise from ignoring differences between quantum and classical physics.
EPR, Bell, and Quantum LocalityJul 24 2010Sep 26 2011Maudlin has claimed that no local theory can reproduce the predictions of standard quantum mechanics that violate Bell's inequality for Bohm's version (two spin-half particles in a singlet state) of the Einstein-Podolsky-Rosen problem. It is argued that, ... More
Consistent Quantum Realism: A Reply to Bassi and GhirardiJan 25 2000A recent claim by Bassi and Ghirardi that the consistent (decoherent) histories approach cannot provide a realistic interpretation of quantum theory is shown to be based upon a misunderstanding of the single-framework rule: they have replaced the correct ... More