Results for "Scott A. Hill"

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Holding strategies in a bus-route modelSep 01 2007Nov 10 2007A major source of delays in public transportation is the clustering instability, which causes late buses to become progressively later while the buses trailing it become progressively earlier. In this paper, we study this instability and how to neutralize ... More
Numerical analysis of a time-headway bus route modelMar 19 2003In this paper, we consider a time-headway model, introduced in Physica A 296:320 (2001), for buses on a bus route. By including a simple no-passing rule, we are able to enumerate and study the unstable modes of a homogeneous system. We then discuss the ... More
Reconciliation of stability analysis with simulation in a bus route modelJun 03 2002Jun 12 2002In a recent paper (Physica A 296, 320 (2001)), T. Nagatani proposes a time-headway model for buses on a bus route, and studies the stability of that model's homogeneous solutions. While investigating the phase diagram gotten by varying the rate of passenger ... More
A measure for characterizing heavy-tailed networksJul 10 2019Heavy-tailed networks are often characterized in the literature by their degree distribution's similarity to a power law. However, many heavy-tailed networks in real life do not have power-law degree distributions, and in many applications the scale-free ... More
A dynamic model of time-dependent complex networksJan 28 2009Jul 14 2010The characterization of the "most connected" nodes in static or slowly evolving complex networks has helped in understanding and predicting the behavior of social, biological, and technological networked systems, including their robustness against failures, ... More
Granular clustering in a hydrodynamic simulationFeb 27 2003We examine the hydrodynamics of a granular gas using numerical simulation. We demonstrate the appearance of shearing and clustering instabilities predicted by linear stability analysis, and show that their appearance is directly related to the inelasticity ... More
A nonlinear hydrodynamical approach to granular materialsAug 02 2000Jan 05 2001We propose a nonlinear hydrodynamical model of granular materials. We show how this model describes the formation of a sand pile from a homogeneous distribution of material under gravity, and then discuss a simulation of a rotating sandpile which shows, ... More
Granular clustering in a hydrodynamic simulationJun 24 2002We present a numerical simulation of a granular material using hydrodynamic equations. We show that, in the absence of external forces, such a system phase-separates into high density and low density regions. We show that this separation is dependent ... More
Comment: The Essential Role of Pair MatchingOct 20 2009Comment on "The Essential Role of Pair Matching in Cluster-Randomized Experiments, with Application to the Mexican Universal Health Insurance Evaluation" [arXiv:0910.3752]
Entanglement of a Pair of Quantum BitsMar 22 1997Mar 24 1997The ``entanglement of formation'' of a mixed state of a bipartite quantum system can be defined in terms of the number of pure singlets needed to create the state with no further transfer of quantum information. We find an exact formula for the entanglement ... More
Neurokinematic Modeling of Complex Swimming Patterns of the Larval ZebrafishNov 12 2004Larval zebrafish exhibit a variety of complex undulatory swimming patterns. This repertoire is controlled by the 300 neurons projecting from brain into spinal cord. Understanding how descending control signals shape the output of spinal circuits, however, ... More
Model comparison and assessment for single particle tracking in biological fluidsJul 22 2014Nov 29 2015State-of-the-art techniques in passive particle-tracking microscopy provide high-resolution path trajectories of diverse foreign particles in biological fluids. For particles on the order of 1 micron diameter, these paths are generally inconsistent with ... More
On the algebras over equivariant little disksSep 06 2017We describe the structure present in algebras over the little disks operads for various representations of a finite group $G$, including those that are not necessarily universe or that do not contain trivial summands. We then spell out in more detail ... More
Is there a polarization horizon?Oct 29 2018Nov 28 2018Modern radio spectrometers make measurement of polarized intensity as a function of Faraday depth possible. I investigate the effect of depolarization along a model line of sight. I model sightlines with two components informed by observations: a diffuse ... More
The Equivariant Slice Filtration: a PrimerJul 18 2011Aug 02 2012We present an introduction to the equivariant slice filtration. After reviewing the definitions and basic properties, we determine the slice dimension of various families of naturally arising spectra. This leads to an analysis of pullbacks of slices defined ... More
Ext and the Motivic Steenrod Algebra over $\R$Apr 13 2009We present a descent style, Bockstein spectral sequence computing Ext over the motivic Steenrod algebra over $\R$ and related sub-Hopf algebras. We demonstrate the workings of this spectral sequence in several examples, providing motivic analogues to ... More
The 3-local tmf homology of BSigma_3Nov 28 2005In this paper, we introduce a Hopf algebra, developed by the author and Andre Henriques, which is usable in the computation of the tmf homology of a space. As an application, we compute the tmf homology of BSigma_3 in a manner analogous to Mahowald's ... More
The 5-local homotopy of $eo_4$Sep 02 2008We compute the 5-local cohomology of a 5-local analogue of the Weierstrass Hopf algebroid used to compute $tmf$ homology. We compute the Adams-Novikov differentials in the cohomology, giving the homotopy, V(0)-homology, and V(1)-homology of the putative ... More
The String bordism of $BE_8$ and $BE_8\times BE_8$ through dimension 14Jul 14 2008We compute the low dimensional String bordism groups of $BE_8$ and $BE_8\times BE_8$ using a combination of Adams spectral sequences together with comparisons to the Spin bordism cases.
Scaling behavior of disordered lattice fermions in two dimensionsNov 10 2012We propose a lattice model for Dirac fermions which allows us to break the degeneracy of the node structure. In the presence of a random gap we analyze the scaling behavior of the localization length as a function of the system width within a numerical ... More
Anderson localization in a two-dimensional random gap modelMay 29 2013Oct 08 2013We study the properties of the spinor wavefunction in a strongly disordered environment on a two-dimensional lattice. By employing a transfer-matrix calculation we find that there is a transition from delocalized to localized states at a critical value ... More
Maximum Likelihood Estimation for Single Particle, Passive Microrheology Data with DriftSep 10 2015Feb 22 2016Volume limitations and low yield thresholds of biological fluids have led to widespread use of passive microparticle rheology. The mean-squared-displacement (MSD) statistics of bead position time series (bead paths) are either applied directly to determine ... More
Automated versus do-it-yourself methods for causal inference: Lessons learned from a data analysis competitionJul 09 2017Jul 20 2018Statisticians have made great progress in creating methods that reduce our reliance on parametric assumptions. However this explosion in research has resulted in a breadth of inferential strategies that both create opportunities for more reliable inference ... More
Spin-Orbit Coupling in the ab initio Pseudopotential FrameworkOct 17 2000We describe the implementation of total angular momentum dependent pseudopotentials in a plane wave formulation of density functional theory. Our approach thus goes beyond the scalar-relativistic approximation usually made in ab initio pseudopotential ... More
The $C_2$-spectrum $Tmf_1(3)$ and its invertible modulesJul 29 2015Dec 07 2016We explore the $C_2$-equivariant spectra $Tmf_1(3)$ and $TMF_1(3)$. In particular, we compute their $C_2$-equivariant Picard groups and the $C_2$-equivariant Anderson dual of $Tmf_1(3)$. This implies corresponding results for the fixed point spectra $TMF_0(3)$ ... More
A new formulation of the equivariant slice filtration with applications to $C_p$-slicesMar 30 2017Aug 01 2017This paper provides a new way to understand the equivariant slice filtration. We give a new, readily checked condition for determining when a $G$-spectrum is slice $n$-connective. In particular, we show that a $G$-spectrum is slice greater than or equal ... More
Ab-initio transport theory for digital ferromagnetic heterostructuresAug 25 2001MnAs/GaAs superlattices, made by $\delta$-doping GaAs with Mn, are known as digital ferromagnetic heterostructures. Here we present a theoretical density functional study of the electronic, magnetic and transport properties of such heterostructures. In ... More
The $\mathbb Z$-homotopy fixed points of $C_{n}$ spectra with applications to norms of $MU_{\mathbb R}$Aug 30 2018We introduce a computationally tractable way to describe the $\mathbb Z$-homotopy fixed points of a $C_{n}$-spectrum $E$, producing a genuine $C_{n}$ spectrum $E^{hn\mathbb Z}$ whose fixed and homotopy fixed points agree and are the $\mathbb Z$-homotopy ... More
Anomaly mediated neutrino-photon interactions at finite baryon densityAug 09 2007Aug 19 2007We propose new physical processes based on the axial vector anomaly and described by the Wess-Zumino-Witten term that couples the photon, Z-boson, and the omega-meson. The interaction takes the form of a pseudo-Chern-Simons term, $\sim \epsilon_{\mu\nu\rho\sigma}\omega^\mu ... More
Cusps and the family hyperbolic metricAug 24 2005Mar 13 2007The hyperbolic metric for the punctured unit disc in the Euclidean plane is singular at the origin. A renormalization of the metric at the origin is provided by the Euclidean metric. For Riemann surfaces there is a unique germ for the isometry class of ... More
Chromatic Adaptation Transform by Spectral Reconstruction (Preprint)Feb 26 2019Jul 04 2019A color appearance model (CAM) is an advanced colorimetric tool used to predict color appearance under a wide variety of viewing conditions. A chromatic adaptation transform (CAT) is an integral part of a CAM. Its role is to predict "corresponding colors," ... More
Probing strong-field gravity and black holes with gravitational wavesFeb 12 2010Gravitational wave observations will be excellent tools for making precise measurements of processes that occur in very strong-field regions of spacetime. Extreme mass ratio systems, formed by the capture of a stellar mass body compact by a massive black ... More
The evolution of circular, non-equatorial orbits of Kerr black holes due to gravitational-wave emissionOct 26 1999Jan 05 2001A major focus of much current research in gravitation theory is on understanding how radiation reaction drives the evolution of a binary system, particularly in the extreme mass ratio limit. Such research is of direct relevance to gravitational-wave sources ... More
Untangling the merger history of massive black holes with LISAAug 30 2001Binary black hole coalescences emit gravitational waves that will be measurable by the space-based detector it LISA to large redshifts. This suggests that LISA may be able to observe black holes grow and evolve as the universe evolves, mapping the distribution ... More
Nearly horizon skimming orbits of Kerr black holesJan 05 2001An unusual set of orbits about extreme Kerr black holes resides at the Boyer-Lindquist radius $r = M$, the coordinate of the hole's event horizon. These ``horizon skimming'' orbits have the property that their angular momentum $L_z$ {\it increases} with ... More
Exceptional surgeries on knots with exceptional classesMay 07 2013We survey aspects of classical combinatorial sutured manifold theory and show how they can be adapted to study exceptional Dehn fillings and 2-handle additions. As a consequence we show that if a hyperbolic knot $\beta$ in a compact, orientable, hyperbolic ... More
Small Covers of the Dodecahedron and the 120-cellJul 16 2001Jul 18 2001Let P be the right-angled dodecahedron or 120-cell in hyperbolic space, and let W be the group generated by reflections across codimension-one faces of P. We prove that if Gamma is a torsion-free subgroup of minimal index in W, then the corresponding ... More
Equiboundedness of the Weil-Petersson metricMar 02 2015May 26 2016Uniform bounds are developed for derivatives of solutions of the $2$-dimensional constant negative curvature equation and the Weil-Petersson metric for the Teichm\"{u}ller and moduli spaces. The dependence of the bounds on the geometry of the underlying ... More
Lectures and notes: Mirzakhani's volume recursion and approach for the Witten-Kontsevich theorem on moduli tautological intersection numbersJul 31 2011The materials accompany a lecture short course presented at the 2011 Park City Mathematics Institute, Graduate Summer School on Moduli Spaces of Riemann Surfaces. The lectures were part of/coordinated with an overall program, including lectures by Ursula ... More
Understanding Weil-Petersson curvatureSep 22 2008A brief history of the investigation of the Weil-Petersson curvature and a summary of Teichm\"{u}ller theory are provided. A report is presented on the program to describe an intrinsic geometry with the Weil-Petersson metric and geodesic-length functions. ... More
Geometry of the Weil-Petersson completion of Teichmüller spaceFeb 24 2005We present a view of the current understanding of the geometry of Weil-Petersson (WP) geodesics on the completion of the Teichm\"uller space. We sketch a collection of results by other authors and then proceed to develop the properties of the WP CAT(0) ... More
Wideband Microstrip Antenna DesignMay 27 2014This paper covers wideband planar antenna design approaches. Modeling and simulation results were obtained using ADS simulation software and have demonstrated feasibility for fabrication of a wideband patch antenna configuration for moderately low-power ... More
Optimizing quantum process tomography with unitary 2-designsNov 07 2007Jan 24 2008We show that weighted unitary 2-designs define optimal measurements on the system-ancilla output state for ancilla-assisted process tomography of unital quantum channels. Examples include complete sets of mutually unbiased unitary-operator bases. Each ... More
Products of twists, geodesic-lengths and Thurston shearsMar 01 2013Thurston introduced shear deformations (cataclysms) on geodesic laminations - deformations including left and right displacements along geodesics. For hyperbolic surfaces with cusps, we consider shear deformations on disjoint unions of ideal geodesics. ... More
Chromatic Adaptation Transform by Spectral Reconstruction (Preprint)Feb 26 2019May 21 2019A color appearance model (CAM) is an advanced colorimetric tool used to predict color appearance under a wide variety of viewing conditions. A chromatic adaptation transform (CAT) is an integral part of a CAM. Its role is to predict "corresponding colors," ... More
Bound orbits of a slowly evolving black holeJun 23 2018Bound geodesic orbits of black holes are very well understood. Given a Kerr black hole of mass $M$ and spin $S = aM^2$, it is a simple matter to characterize its orbits as functions of the orbital geometry. How do the orbits change if the black hole is ... More
Listening to the Universe with Gravitational-Wave AstronomyOct 22 2002Nov 03 2002The LIGO (Laser Interferometer Gravitational-Wave Observatory) detectors have just completed their first science run, following many years of planning, research, and development. LIGO is a member of what will be a worldwide network of gravitational-wave ... More
Evolution of circular, non-equatorial orbits of Kerr black holes due to gravitational-wave emission: II. Inspiral trajectories and gravitational waveformsApr 13 2001May 24 2001The inspiral of a ``small'' ($\mu \sim 1-100 M_\odot$) compact body into a ``large'' ($M \sim 10^{5-7} M_\odot$) black hole is a key source of gravitational radiation for the space-based gravitational-wave observatory LISA. The waves from such inspirals ... More
LISA sources and scienceNov 01 2007LISA is a planned space-based gravitational-wave (GW) detector that would be sensitive to waves from low-frequency sources, in the band of roughly (0.03 - 0.1) mHz < f < 0.1 Hz. This is expected to be an extremely rich chunk of the GW spectrum -- observing ... More
Behavior of geodesic-length functions on Teichmueller spaceJan 19 2007Jan 01 2008Let $\mathcal T$ be the Teichm\"{u}ller space of marked genus $g$, $n$ punctured Riemann surfaces with its bordification $\Tbar$ the {\em augmented Teichm\"{u}ller space} of marked Riemann surfaces with nodes, \cite{Abdegn, Bersdeg}. Provided with the ... More
Families of Riemann surfaces and Weil-Petersson geometryFeb 18 2012A 2008 general overview on Weil-Petersson geometry is offered. A preliminary plan for the subsequent CBMS lectures at Central Connecticut State University is included. Mirzakhani's solution of Witten-Kontsevich is not included - this work essentially ... More
Hamiltonian mappings and circle packing phase spaces: numerical investigationsNov 04 2002In a previous paper we introduced examples of Hamiltonian mappings with phase space structures resembling circle packings. We now concentrate on one particular mapping and present numerical evidence which supports the conjecture that the set of circular ... More
Supermatrix ModelsNov 19 1991Random matrix models based on an integral over supermatrices are proposed as a natural extension of bosonic matrix models. The subtle nature of superspace integration allows these models to have very different properties from the analogous bosonic models. ... More
Chromatic Adaptation Transform by Spectral Reconstruction (Preprint)Feb 26 2019Apr 23 2019A color appearance model (CAM) is an advanced colorimetric tool used to predict color appearance under a wide variety of viewing conditions. A chromatic adaptation transform (CAT) is an integral part of a CAM. Its role is to predict "corresponding colors," ... More
A Torsion-Free Milnor-Moore TheoremMar 30 2001Aug 05 2001Let \Omega X be the space of Moore loops on a finite, q-connected, n-dimensional CW complex X, and let R be a subring of Q containing 1/2. Let p(R) be the least non-invertible prime in R. For a graded R-module M of finite type, let FM = M / Torsion M. ... More
Adiabatic and post-adiabatic approaches to extreme mass ratio inspiralJan 08 2016Extreme mass ratio inspirals (EMRIs) show a strong separation of timescales, with the time characterizing inspiral, $T_{\rm i}$, much longer than any time $T_{\rm o}$ characterizing orbital motions. The ratio of these timescales (which is essentially ... More
Gravitational waves from merging compact binariesMar 27 2009Apr 18 2009Largely motivated by the development of highly sensitive gravitational-wave detectors, our understanding of merging compact binaries and the gravitational waves they generate has improved dramatically in recent years. Breakthroughs in numerical relativity ... More
A brief survey of LISA sources and scienceSep 07 2006Sep 10 2006LISA is a planned space-based gravitational-wave (GW) detector that would be sensitive to waves from low-frequency sources, in the band of roughly $(0.03 - 0.1) {\rm mHz} \lesssim f \lesssim 0.1 {\rm Hz}$. This is expected to be an extremely rich chunk ... More
Computing radiation from Kerr black holes: Generalization of the Sasaki-Nakamura equationFeb 11 2000Apr 14 2000As shown by Teukolsky, the master equation governing the propagation of weak radiation in a black hole spacetime can be separated into four ordinary differential equations, one for each spacetime coordinate. (``Weak'' means the radiation's amplitude is ... More
Band taut sutured manifoldsSep 24 2011Jul 29 2013Attaching a 2-handle to a genus two or greater boundary component of a 3-manifold is a natural generalization of Dehn filling a torus boundary component. We prove that there is an interesting relationship between an essential surface in a sutured 3-manifold, ... More
Convexity of geodesic-length functions: a repriseFeb 24 2005New results on the convexity of geodesic-length functions on Teichm\"{u}ller space are presented. A formula for the Hessian of geodesic-length is presented. New bounds for the gradient and Hessian of geodesic-length are described. A relationship of geodesic-length ... More
Geodesic-length functions and the Weil-Petersson curvature tensorAug 13 2010Oct 04 2011An expansion is developed for the Weil-Petersson Riemann curvature tensor in the thin region of the Teichm\"{u}ller and moduli spaces. The tensor is evaluated on the gradients of geodesic-lengths for disjoint geodesics. A precise lower bound for sectional ... More
The Weil-Petersson metric geometryDec 31 2007A summary introduction of the Weil-Petersson metric space geometry is presented. Teichmueller space and its augmentation are described in terms of Fenchel-Nielsen coordinates. Formulas for the gradients and Hessians of geodesic-length functions are presented. ... More
Anomalous diffusion of distinguished particles in bead-spring networksNov 22 2009We consider the anomalous sub-diffusion of a class of Gaussian processes that can be expressed in terms of sums of Ornstein-Uhlenbeck processes. As a generic class of processes, we introduce a single parameter such that for any $\nu \in (0,1)$ the process ... More
Spectral and temporal characterization of a fused-quartz microresonator optical frequency combJun 13 2011We report on the fabrication of high-Q, fused-quartz microresonators and the parametric generation of a frequency comb with 36 GHz line spacing using them. We have characterized the intrinsic stability of the comb in both the time and frequency domains ... More
Infinitesimal deformations of nodal stable curvesApr 17 2012An analytic approach and description are presented for the moduli cotangent sheaf for suitable stable curve families including noded fibers. For sections of the square of the relative dualizing sheaf, the residue map at a node gives rise to an exact sequence. ... More
(Sort of) Testing relativity with extreme mass ratio inspiralsAug 31 2006The inspirals of ``small'' ($1 - 100 M_\odot$) compact bodies through highly relativistic orbits of massive (several $\times 10^5 M_\odot -$ several $\times 10^6 M_\odot$) black holes are among the most anticipated sources for the LISA gravitational-wave ... More
Tuning gravitational-wave detector networks to measure compact binary mergersSep 04 2002Gravitational waves generated by the final merger of compact binary systems depend on the structure of the binary's members. If the binary contains neutron stars, measuring such waves can teach us about the properties of matter at extreme densities. Unfortunately, ... More
Gravitational waves from extreme mass ratio inspirals: Challenges in mapping the spacetime of massive, compact objectsAug 23 2000In its final year of inspiral, a stellar mass ($1 - 10 M_\odot$) body orbits a massive ($10^5 - 10^7 M_\odot$) compact object about $10^5$ times, spiralling from several Schwarzschild radii to the last stable orbit. These orbits are deep in the massive ... More
Trust but verify: The case for astrophysical black holesNov 17 2005Nov 21 2005This article is based on a pair of lectures given at the 2005 SLAC Summer Institute. Our goal is to motivate why most physicists and astrophysicists accept the hypothesis that the most massive, compact objects seen in many astrophysical systems are described ... More
Comment on "Gravity Waves, Chaos, and Spinning Compact Binaries"Jan 05 2001In this comment, I argue that chaotic effects in binary black hole inspiral will not strongly impact the detection of gravitational waves from such systems.
Gravitational waves from inspiral into massive black holesDec 08 1999Space-based gravitational-wave interferometers such as LISA will be sensitive to the inspiral of stellar mass compact objects into black holes with masses in the range of roughly 10^5 solar masses to (a few) 10^7 solar masses. During the last year of ... More
Abstractly Planar Spatial GraphsFeb 05 2019This is a survey article for the forthcoming `A Concise Encyclopedia of Knot Theory.' We focus on the topology of spatial graphs with few vertices and edges, paying particular attention to Brunnian $\theta$-graphs.
Boring split linksSep 26 2007Jan 15 2009Boring is an operation which converts a knot or two-component link in a 3--manifold into another knot or two-component link. It generalizes rational tangle replacement and can be described as a type of 2--handle attachment. Sutured manifold theory is ... More
Comparing 2-handle additions to a genus 2 boundary componentJun 10 2008Sep 24 2011We prove that knots obtained by attaching a band to a split link satisfy the cabling conjecture. We also give new proofs that unknotting number one knots are prime and that genus is superadditive under band sum. Additionally, we prove a collection of ... More
Algebraic structure of the loop space Bockstein spectral sequenceDec 13 1999Let X be a finite, n-dimensional, r-connected CW complex. We prove the following theorem: If p \geq n/r is an odd prime, then the loop space homology Bockstein spectral sequence modulo p is a spectral sequence of universal enveloping algebras over differential ... More
Schiffer variations and Abelian differentialsAug 05 2015Sep 14 2015Deformations of compact Riemann surfaces are considered using a \v{C}ech cohomology sliding overlaps approach. Cocycles are calculated for conformal cutting and regluing deformations at zeros of Abelian differentials. A second order deformation expansion ... More
Extension of the Weil-Petersson connectionSep 16 2007Convexity properties of Weil-Petersson geodesics on the Teichm\"{u}ller space of punctured Riemann surfaces are investigated. A normal form is presented for the Weil-Petersson Levi-Civita connection for pinched hyperbolic metrics. The normal form is used ... More
Weil-Petersson Metric Geometry Quick OverviewMay 08 2007Jul 03 2007A quick overview is provided on the current development of the WP metric geometry.
PyCraters: A Python framework for crater function analysisOct 28 2014We introduce a Python framework designed to automate the most common tasks associated with the extraction and upscaling of the statistics of single-impact crater functions to inform coefficients of continuum equations describing surface morphology evolution. ... More
Gravitational wave astronomy and cosmologyMay 02 2014The first direct observation of gravitational waves' action upon matter has recently been reported by the BICEP2 experiment. Advanced ground-based gravitational-wave detectors are being installed. They will soon be commissioned, and then begin searches ... More
On families of holomorphic differentials on degenerating annuliAug 16 2011Nov 23 2011We consider the local analytic behavior for a family of holomorphic differentials on a family of degenerating annuli. Three results and discussion are presented. The first is the normal families Lemma 1. The second is an isomorphism of sheaves, formula ... More
Weil-Petersson perspectivesFeb 24 2005Mar 06 2005We highlight recent progresses in the study of the Weil-Petersson (WP) geometry of finite dimensional Teichm\"{u}ller spaces. For recent progress on and the understanding of infinite dimensional Teichm\"{u}ller spaces the reader is directed to the recent ... More
The properties of the putative pulsar associated with IGR J18135-1751/HESS J1813-178Apr 21 2008Context: We investigate the possible theoretical properties of the putative pulsar associated with the pulsar wind nebula IGR J18135-1751/HESS J1813-178 based upon recent gamma-ray observations and archival multi-wavelength observations. Aims: We show ... More
Optical Hall conductivity of systems with gapped spectral nodesMay 18 2010Dec 19 2012We calculate the optical Hall conductivity within the Kubo formalism for systems with gapped spectral nodes, where the latter have a power-law dispersion with exponent n. The optical conductivity is proportional to n and there is a characteristic logarithmic ... More
Using ALMA to resolve the nature of the early star-forming large-scale structure PLCK G073.4-57.5Apr 18 2018Apr 22 2019Galaxy clusters at high redshift are key targets for understanding matter assembly in the early Universe, yet they are challenging to locate. A sample of >2000 high-z candidate structures has been found using Planck's all-sky submm maps, and a sub-set ... More
Dielectric function and plasmons in grapheneApr 28 2009The electromagnetic response of graphene, expressed by the dielectric function, and the spectrum of collective excitations are studied as a function of wave vector and frequency. Our calculation is based on the full band structure, calculated within the ... More
The SCUBA-2 Ambitious Sky Survey: a catalogue of beam-sized sources in the Galactic longitude range 120 to 140Mar 06 2017The SCUBA-2 Ambitious Sky Survey (SASSy) is composed of shallow 850-$\umu$m imaging using the Sub-millimetre Common-User Bolometer Array 2 (SCUBA-2) on the James Clerk Maxwell Telescope. Here we describe the extraction of a catalogue of beam-sized sources ... More
Fiber-optical analogue of the event horizonNov 29 2007Feb 13 2008The physics at the event horizon resembles the behavior of waves in moving media. Horizons are formed where the local speed of the medium exceeds the wave velocity. We use ultrashort pulses in microstructured optical fibers to demonstrate the formation ... More
A Multiscale maximum entropy moment closure for locally regulated space-time point process models of population dynamicsFeb 27 2012The pervasive presence spatial and size structure in biological populations challenges fundamental assumptions at the heart of continuum models of population dynamics based on mean densities (local or global) only. Individual-based models (IBM's) were ... More
First principles study of the origin and nature of ferromagnetism in (Ga,Mn)AsNov 02 2000The properties of diluted Ga$_{1-x}$Mn$_x$As are calculated for a wide range of Mn concentrations within the local spin density approximation of density functional theory. M\"ulliken population analyses and orbital-resolved densities of states show that ... More
Incomplete Tambara functorsMar 10 2016For a "genuine" equivariant commutative ring spectrum $R$, $\pi_0(R)$ admits a rich algebraic structure known as a Tambara functor. This algebraic structure mirrors the structure on $R$ arising from the existence of multiplicative norm maps. Motivated ... More
Abell 2111: An Optical and Radio Study of the Richest Butcher-Oemler ClusterFeb 03 2006We present an in-depth analysis of the Butcher-Oemler cluster A2111, including new optical spectroscopy plus a deep Very Large Array (VLA) radio continuum observation. These are combined with optical imaging from the Sloan Digital Sky Survey (SDSS) to ... More
The optical ephemeris and X-ray variability of 4U 1735-44 (V926 Sco)Mar 09 2012Optical observations of the low mass X-ray binary 4U 1735-44 were obtained during 1997-2007 and combined with earlier published observations from 1984-1993 to refine the ephemeris for the system. The linear fit for the time of maximum optical light has ... More
`Exact' solutions of the full electrokinetic model for soft spherical colloids: Electrophoretic mobilityMay 04 2005Numerical solutions of the standard electrokinetic model provide a basis for interpreting a variety of electrokinetic phenomena involving `bare' colloids. However, the model rests on the classical notion of a shear or slipping plane, whose location is ... More
Closed-form solutions for tilted three-part piecewise-quadratic half-plane contactsFeb 20 2019A general half-plane contact problem in which the geometry is specified in a piecewise-quadratic sense over three segments is solved in closed form. This includes the effects of a moment applied sufficient to introduce separation of one segment and the ... More
Equivariant symmetric monoidal structuresOct 10 2016Building on structure observed in equivariant homotopy theory, we define an equivariant generalization of a symmetric monoidal category: a $G$-symmetric monoidal category. These record not only the symmetric monoidal products but also symmetric monoidal ... More
The right adjoint to the equivariant operadic forgetful functor on incomplete Tambara functorsNov 30 2017Mar 01 2018For $N_\infty$ operads $\mathcal O$ and $\mathcal O'$ such that there is an inclusion of the associated indexing systems, there is a forgetful functor from incomplete Tambara functors over $\mathcal O'$ to incomplete Tambara functors over $\mathcal O$. ... More
Optical spectroscopy of radio galaxies in the 7C Redshift SurveyMay 29 2002We present optical spectroscopy of all 49 radio galaxies in the 7C-I and 7C-II regions of the 7C Redshift Survey (7CRS). The low-frequency (151 MHz) selected 7CRS sample contains all sources with flux-densities S_151 > 0.5 Jy in three regions of the sky; ... More
Neural Arithmetic Logic UnitsAug 01 2018Neural networks can learn to represent and manipulate numerical information, but they seldom generalize well outside of the range of numerical values encountered during training. To encourage more systematic numerical extrapolation, we propose an architecture ... More