Results for "Douglas A. Baxter"

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Molecular Constraints on Synaptic Tagging and Maintenance of Long-Term Potentiation: A Predictive ModelJun 16 2012Aug 03 2012Protein synthesis-dependent, late long-term potentiation (LTP) and depression (LTD) at glutamatergic hippocampal synapses are well characterized examples of long-term synaptic plasticity. Persistent increased activity of the enzyme protein kinase M (PKM) ... More
How Can Memories Last for Days, Years, or a Lifetime? Proposed Mechanisms for Maintaining Synaptic Potentiation and MemoryMar 13 2019Apr 16 2019With memory encoding reliant on persistent changes in the properties of synapses, a key question is how can memories be maintained from days to months or a lifetime given molecular turnover? It is likely that positive feedback loops are necessary to persistently ... More
Interlinked Dual-Time Feedback Loops can Enhance Robustness to Stochasticity and Persistence of MemoryAug 29 2012Multiple interlinked positive feedback loops shape the stimulus responses of various biochemical systems, such as the cell cycle or intracellular calcium release. Recent studies with simplified models have identified two advantages of coupling fast and ... More
Simulations Suggest Pharmacological Methods for Rescuing Long-Term PotentiationAug 08 2014Congenital cognitive dysfunctions are frequently due to deficits in molecular pathways that underlie synaptic plasticity. For example, Rubinstein-Taybi syndrome (RTS) is due to a mutation in cbp, encoding the histone acetyltransferase CREB-binding protein ... More
Bistable MAP Kinase Activity: A Plausible Mechanism Contributing to Maintenance of Late Long-Term PotentiationFeb 18 2008Bistability of MAP kinase (MAPK) activity has been suggested to contribute to several cellular processes, including differentiation and long-term synaptic potentiation. A recent model (48) predicts bistability due to interactions of the kinases and phosphatases ... More
How Can Memories Last for Days, Years, or a Lifetime? Proposed Mechanisms for Maintaining Synaptic Potentiation and MemoryMar 13 2019With memory encoding reliant on persistent changes in the properties of synapses, a key question is how can memories be maintained from days to months or a lifetime given molecular turnover? It is likely that positive feedback loops are necessary to persistently ... More
Paradoxical LTP maintenance with inhibition of protein synthesis and the proteasome suggests a novel protein synthesis requirement for early LTP reversalAug 20 2018The transition from early long-term potentiation (E-LTP) to late LTP (L-LTP) involves protein synthesis and degradation. L-LTP is blocked by inhibiting either protein synthesis or proteasome-dependent degradation prior to and during a tetanic stimulus, ... More
A Model of the Roles of Essential Kinases in the Induction and Expression of Late Long-Term PotentiationJan 03 2006The induction of late long-term potentiation (L-LTP) involves complex interactions among second messenger cascades. To gain insights into these interactions, a mathematical model was developed for L-LTP induction in the CA1 region of the hippocampus. ... More
ISiCLE: A molecular collision cross section calculation pipeline for establishing large in silico reference libraries for compound identificationSep 22 2018Comprehensive and confident identifications of metabolites and other chemicals in complex samples will revolutionize our understanding of the role these chemically diverse molecules play in biological systems. Despite recent advances, metabolomics studies ... More
Conditionally Positive Functions and p-norm Distance MatricesJun 12 2010In Micchelli's paper "Interpolation of scattered data: distance matrices and conditionally positive functions", deep results were obtained concerning the invertibility of matrices arising from radial basis function interpolation. In particular, the Euclidean ... More
A Model of Inductive Bias LearningJun 01 2011A major problem in machine learning is that of inductive bias: how to choose a learner's hypothesis space so that it is large enough to contain a solution to the problem being learnt, yet small enough to ensure reliable generalization from reasonably-sized ... More
Preconditioned Conjugate Gradients, Radial Basis Functions and Toeplitz MatricesJun 12 2010Radial basis functions provide highly useful and flexible interpolants to multivariate functions. Further, they are beginning to be used in the numerical solution of partial differential equations. Unfortunately, their construction requires the solution ... More
The Interpolation Theory of Radial Basis FunctionsJun 12 2010In this dissertation, it is first shown that, when the radial basis function is a $p$-norm and $1 < p < 2$, interpolation is always possible when the points are all different and there are at least two of them. We then show that interpolation is not always ... More
The Lack of Halo Ultraluminous X-ray SourcesSep 11 2006The premise that Ultraluminous X-ray sources (ULXs) exist beyond the optical extent of nearby galaxies is investigated. A published catalog containing 41 ULX candidates located between 1 and ~3 times the standard D_{25} isophotal radius of their putative ... More
The Qth-power algorithm in characteristic 0Jan 25 2013The Qth-power algorithm produces a useful canonical P-module presentation for the integral closures of certain integral extensions of $P:=\mathbf{F}[x_n,...,x_1]$, a polyonomial ring over the finite field $\mathbf{F}:=\mathbf{Z}_q$ of $q$ elements. Here ... More
S-matrix poles and the second virial coefficientMay 01 2001For cutoff potentials, a condition which is not a limitation for the calculation of physical systems, the S-matrix is meromorphic. We can express it in terms of its poles, and then calculate the quantum mechanical second virial coefficient of a neutral ... More
Correlated Edge Overlaps in Multiplex NetworksFeb 10 2016Apr 20 2016We develop the theory of sparse multiplex networks with partially overlapping links based on their local tree-likeness. This theory enables us to find the giant mutually connected component in a two-layer multiplex network with arbitrary correlations ... More
Parity-Time Symmetry Breaking beyond One Dimension: The Role of DegeneracyFeb 03 2014Aug 13 2014We consider the role of degeneracy in Parity-Time (PT) symmetry breaking for non-hermitian wave equations beyond one dimension. We show that if the spectrum is degenerate in the absence of T-breaking, and T is broken in a generic manner (without preserving ... More
Castelnuovo-Mumford regularity and arithmetic Cohen-Macaulayness of complete bipartite subspace arrangementsSep 10 2012Aug 04 2014We give the Castelnuovo-Mumford regularity of arrangements of (n-2)-planes in P^n whose incidence graph is a sufficiently large complete bipartite graph, and determine when such arrangements are arithmetically Cohen-Macaulay.
Existence of topological hairy dyons and dyonic black holes in anti-de Sitter SU(N) Einstein-Yang-Mills theoryJul 19 2015Feb 03 2016We investigate dyonic black hole and dyon solutions of four-dimensional $SU(N)$ Einstein-Yang-Mills theory with a negative cosmological constant. We derive a set of field equations in this case, and prove the existence of non-trivial solutions to these ... More
Stable furry black holes in $\mathfrak{su}(\infty)$ anti-de Sitter Einstein-Yang-Mills theory, characterised by an infinitude of global chargesFeb 10 2019We present solutions to classical field equations for purely magnetic $\mathfrak{su}(\infty)$ Einstein-Yang-Mills theory in asymptotically Anti-de Sitter space. These solutions are found to be stable under linear, time-dependent perturbations. Recent ... More
Functionals of Exponential Brownian Motion and Divided DifferencesJun 10 2010We provide a surprising new application of classical approximation theory to a fundamental asset-pricing model of mathematical finance. Specifically, we calculate an analytic value for the correlation coefficient between exponential Brownian motion and ... More
Convergence of stationary radial basis function-schemes for evolution equationsMay 03 2019We establish precise convergence rates for semi-discrete schemes based on Radial Basis Function interpolation, as well as approximate approximation results for such schemes. Our schemes use stationary interpolation on regular grids, with basis functions ... More
On the existence of topological dyons and dyonic black holes in anti-de Sitter Einstein-Yang-Mills theories with compact semisimple gauge groupsJul 26 2017May 17 2018Here we study the global existence of `hairy' dyonic black hole and dyon solutions to four dimensional, anti-de Sitter Einstein-Yang-Mills theories for a general simply-connected and semisimple gauge group $G$, for so-called topologically symmetric systems, ... More
How Can Memories Last for Days, Years, or a Lifetime? Proposed Mechanisms for Maintaining Synaptic Potentiation and MemoryMar 13 2019Apr 05 2019With memory encoding reliant on persistent changes in the properties of synapses, a key question is how can memories be maintained from days to months or a lifetime given molecular turnover? It is likely that positive feedback loops are necessary to persistently ... More
Refining enumeration schemes to count according to permutation statisticsJan 01 2014We consider the question of computing the distribution of a permutation statistics over restricted permutations via enumeration schemes. The restricted permutations are those avoiding sets of vincular patterns (which include both classical and consecutive ... More
Dyonic black holes in $\mathfrak{su}(\infty)$ anti-de Sitter Einstein-Yang-Mills theory, characterised by an infinite set of global chargesDec 13 2018We here investigate static, spherically symmetric solutions to $\mathfrak{su}(\infty)$ Einstein-Yang-Mills theory with a negative cosmological constant $\Lambda$ in the case of dyonic solutions, which possess a non-trivial electric sector of the gauge ... More
On the existence of topological hairy black holes in $\mathfrak{su}(N)$ EYM theory with a negative cosmological constantMar 02 2014Jul 09 2015We investigate the existence of black hole solutions of four dimensional $\mathfrak{su}(N)$ EYM theory with a negative cosmological constant. Our analysis differs from previous works in that we generalise the field equations to certain non-spherically ... More
On the global existence of spherically symmetric hairy black holes and solitons in anti-de Sitter Einstein-Yang-Mills theories with compact semisimple gauge groupsApr 18 2016We investigate the existence of black hole and soliton solutions to four dimensional, anti-de Sitter (adS), Einstein-Yang-Mills theories with general semisimple connected and simply connected gauge groups, concentrating on the so-called "regular" case. ... More
Surface and corner free energies of the self-dual Potts modelJun 06 2016Jan 26 2017We consider the bulk, vertical surface, horizontal surface and corner free energies $f_b, f_s, f'_s, f_c$ of the anisotropic self-dual $Q$-state Potts model for $Q > 4$. $f_b$ was calculated in 1973[1]. For $Q<4$, $f_s, f'_s$ were calculated in 1989[2]. ... More
Shape-Wilf-equivalences for vincular patternsJan 23 2012Feb 02 2013We extend the notion of shape-Wilf-equivalence to vincular patterns (also known as "generalized patterns" or "dashed patterns"). First we introduce a stronger equivalence on patterns which we call filling-shape-Wilf-equivalence. When vincular patterns ... More
Globally regular solutions to dyonic anti-de Sitter $\mathfrak{su}(\infty)$ Einstein-Yang-Mills theory -- Existence and characterising chargesJan 31 2019In this work, we find new static, spherically symmetric, dyonic, globally regular exact solutions to $\mathfrak{su}(\infty)$ Einstein-Yang-Mills theory with a negative cosmological constant $\Lambda$, in the regime that $|\Lambda|$ is very large. In this ... More
The bulk, surface and corner free energies of the square lattice Ising modelJun 07 2016Jul 18 2016We use Kaufman's spinor method to calculate the bulk, surface and corner free energies $f_b, f_s, f_s', f_c$ of the anisotropic square lattice zero-field Ising model for the ordered ferromagnetic case. For $f_b, f_s, f'_s$ our results of course agree ... More
Enhanced plasmonic coloring of silver and formation of large laser-induced periodic surface structures using multi-burst picosecond pulsesSep 15 2016We report on the creation of angle-independent colors on silver using closely time-spaced laser bursts. The use of burst mode, compared to traditional non-burst is shown to increase the Chroma (color saturation) by ~50% and to broaden the lightness range ... More
Hidden Black: Coherent Enhancement of Absorption in Strongly-scattering MediaAug 04 2011Oct 12 2011We show that a weakly absorbing, strongly scattering (white) medium can be made very strongly absorbing at any frequency within its strong-scattering bandwidth by optimizing the input electromagnetic field. For uniform absorption, results from random ... More
The Effect of Encounters on the Eccentricity of Binaries in ClustersJun 13 1995May 22 1996We derive analytical expressions for the change in the orbital eccentricity of a binary following a distant encounter with a third star on a hyperbolic or parabolic orbit. To establish the accuracy of these expressions, we present detailed comparisons ... More
Forced oscillations of coronal loops driven by EIT wavesJul 08 2008We study the generation of transversal oscillations in coronal loops represented as a straight thin flux tube under the effect of an external driver modeling the global coronal EIT wave. We investigate how the generated oscillations depend on the nature ... More
The Generalized DMPK equation revisited: A systematic derivationMar 21 2013The Generalized Dorokov-Mello-Pereyra-Kumar (DMPK) equation has recently been used to obtain a family of very broad and highly asymmetric conductance distributions for three dimensional disordered conductors. However, there are two major criticisms of ... More
Trees with Equal Total Domination and Game Total Domination NumbersSep 10 2016In this paper, we continue the study of the total domination game in graphs introduced in [Graphs Combin. 31(5) (2015), 1453--1462], where the players Dominator and Staller alternately select vertices of $G$. Each vertex chosen must strictly increase ... More
Shilnikov problem in Filippov dynamical systemsApr 09 2015In this paper we introduce the concept of a sliding Shilnikov orbit for 3D Filippov systems. Versions of the Shilnikov's Theorems are provided for those systems. Specifically, we show that arbitrarily close to a sliding Shilnikov orbit there exist countable ... More
Operator growth in the SYK modelFeb 07 2018We discuss the probability distribution for the "size" of a time-evolving operator in the SYK model. Scrambling is related to the fact that as time passes, the distribution shifts towards larger operators. Initially, the rate is exponential and determined ... More
BayesDB: A probabilistic programming system for querying the probable implications of dataDec 15 2015Is it possible to make statistical inference broadly accessible to non-statisticians without sacrificing mathematical rigor or inference quality? This paper describes BayesDB, a probabilistic programming platform that aims to enable users to query the ... More
Generalized Solitary Waves in the Gravity-Capillary Whitham EquationJul 30 2018We study the existence of traveling wave solutions to a unidirectional shallow water model which incorporates the full linear dispersion relation for both gravitational and capillary restoring forces. Using functional analytic techniques, we show that ... More
Condensation of Thresholds in Multimode MicrolasersJul 27 2016We show from ab initio laser theory that by choosing an appropriate spatial pump profile, many different spatial modes of a typical microlaser can be turned on at the same pump energy, substantially increasing the number, N, of simultaneous lasing modes. ... More
Mesoscopic conductance and its fluctuations at non-zero Hall angleJan 10 1997We consider the bilocal conductivity tensor, the two-probe conductance and its fluctuations for a disordered phase-coherent two-dimensional system of non-interacting electrons in the presence of a magnetic field, including correctly the edge effects. ... More
The Effect of a Rapidity Gap Veto on the Discrete BFKL PomeronMay 02 2016We investigate the sensitivity of the discrete BFKL spectrum, which appears in the gluon Green function when the running coupling is considered, to a lower cut-off in the relative rapidities of the emitted particles. We find that the eigenvalues associated ... More
Progress Towards the Total Domination Game $\frac{3}{4}$-ConjectureDec 09 2015In this paper, we continue the study of the total domination game in graphs introduced in [Graphs Combin. 31(5) (2015), 1453--1462], where the players Dominator and Staller alternately select vertices of $G$. Each vertex chosen must strictly increase ... More
Further investigation of white dwarfs in the open clusters NGC2287 and NGC3532Apr 12 2012We report the results of a CCD imaging survey, complimented by astrometric and spectroscopic follow-up studies, that aims to probe the fate of heavy-weight intermediate mass stars by unearthing new, faint, white dwarf members of the rich, nearby, intermediate ... More
Infinite-Horizon Policy-Gradient EstimationJun 03 2011Gradient-based approaches to direct policy search in reinforcement learning have received much recent attention as a means to solve problems of partial observability and to avoid some of the problems associated with policy degradation in value-function ... More
Artificial Intelligence for Interstellar TravelNov 15 2018Nov 19 2018The large distances involved in interstellar travel require a high degree of spacecraft autonomy, realized by artificial intelligence. The breadth of tasks artificial intelligence could perform on such spacecraft involves maintenance, data collection, ... More
Investigation of the photosensitivity, temperature sustainability and fluorescence characteristics of several Er-doped photosensitive fibersNov 30 2011Three different types of Er doped photosensitive fibers, germanium/erbium (Ge/Er) fiber, tin/germanium/erbium fiber (Sn/Er) and antimony/germanium/erbium fiber (Sb/Er) have been manufactured and studied for use in optical sensor systems. Their characteristics ... More
First Demonstration of a Scintillating Xenon Bubble Chamber for Detecting Dark Matter and Coherent Elastic Neutrino-Nucleus ScatteringFeb 28 2017Jun 08 2017A 30-g xenon bubble chamber, operated at Northwestern University in June and November 2016, has for the first time observed simultaneous bubble nucleation and scintillation by nuclear recoils in a superheated liquid. This chamber is instrumented with ... More
Radiative Corrections to Chargino Production in Electron-Positron Collisions with Polarised BeamsAug 11 2000We study radiative corrections to chargino production at linear colliders with polarised electron beams. We calculate the one-loop corrected cross-sections for polarised electon beams due to three families of quarks and squarks, working in the $\bar{MS}$ ... More
Simulation of Drosophila Circadian Oscillations, Mutations, and Light Responses by a Model with VRI, PDP-1, and CLKJan 23 2004A model of Drosophila circadian rhythm generation was developed to represent feedback loops based on transcriptional regulation of per, Clk (dclock), Pdp-1, and vri (vrille). The model postulates that histone acetylation kinetics make transcriptional ... More
Interacting Quantum Dot Coupled to a Kondo Spin: A Universal Hamiltonian StudyFeb 26 2008We study a mesoscopic interacting quantum dot described by the "universal Hamiltonian" that is coupled to a Kondo spin. The ferromagnetic exchange interaction within the dot leads to a stepwise increase of the ground state spin; this Stoner staircase ... More
Eigenvalues and Eigenfunctions of the Scalar Laplace Operator on Calabi-Yau ManifoldsMay 23 2008Jul 10 2008A numerical algorithm for explicitly computing the spectrum of the Laplace-Beltrami operator on Calabi-Yau threefolds is presented. The requisite Ricci-flat metrics are calculated using a method introduced in previous papers. To illustrate our algorithm, ... More
Discovery of a Transient X-ray Source in the Compact Stellar Nucleus of NGC 2403Feb 28 2007We report the discovery of an X-ray source coincident with the nuclear star cluster at the dynamical center of the nearby late-type spiral galaxy NGC 2403. The X-ray luminosity of this source varies from below detection levels, ~1e35 erg/s in the 0.5-8.0 ... More
Soliton and black hole solutions of su(N) Einstein-Yang-Mills theory in anti-de Sitter spaceAug 17 2007Nov 01 2007We present new soliton and hairy black hole solutions of su(N) Einstein-Yang-Mills theory in asymptotically anti-de Sitter space. These solutions are described by N+1 independent parameters, and have N-1 gauge field degrees of freedom. We examine the ... More
Ascent sequences avoiding pairs of patternsJun 16 2014Feb 15 2015Ascent sequences were introduced by Bousquet-Melou et al. in connection with (2+2)-avoiding posets and their pattern avoidance properties were first considered by Duncan and Steingrimsson. In this paper, we consider ascent sequences of length $n$ avoiding ... More
Radiation-hydrodynamical simulations of massive star formation using Monte Carlo radiative transfer II. The formation of a 25 solar-mass starJun 13 2017We present a numerical simulation of the formation of a massive star using Monte- Carlo-based radiation hydrodynamics (RHD). The star forms via stochastic disc accretion and produces fast, radiation-driven bipolar cavities. We find that the evolution ... More
Modelling massive-star feedback with Monte Carlo radiation hydrodynamics: photoionization and radiation pressure in a turbulent cloudApr 19 2018We simulate a self-gravitating, turbulent cloud of 1000 Msol with photoionization and radiation pressure feedback from a 34 Msol star. We use a detailed Monte Carlo radiative transfer scheme alongside the hydrodynamics to compute photoionization and thermal ... More
On the Inequivalence of Weak-Localization and Coherent BackscatteringMay 26 1994We define a current-conserving approximation for the local conductivity tensor of a disordered system which includes the effects of weak localization. Using this approximation we show that the weak localization effect in conductance is not obtained simply ... More
Maximum-entropy Surrogation in Network Signal DetectionFeb 29 2012Multiple-channel detection is considered in the context of a sensor network where raw data are shared only by nodes that have a common edge in the network graph. Established multiple-channel detectors, such as those based on generalized coherence or multiple ... More
Polarization state of radiation from a photonic crystal slabAug 07 2017We point out that the polarization state of radiation from a photonic crystal slab is strongly constrained by the direct non-resonant scattering process. The phase difference between the two linearly-polarized components in the far field can be predicted ... More
Game Total Domination Critical GraphsSep 18 2017In the total domination game played on a graph $G$, players Dominator and Staller alternately select vertices of $G$, as long as possible, such that each vertex chosen increases the number of vertices totally dominated. Dominator (Staller) wishes to minimize ... More
Beyond Ohba's Conjecture: A bound on the choice number of $k$-chromatic graphs with $n$ verticesAug 30 2013Aug 27 2014Let $\text{ch}(G)$ denote the choice number of a graph $G$ (also called "list chromatic number" or "choosability" of $G$). Noel, Reed, and Wu proved the conjecture of Ohba that $\text{ch}(G)=\chi(G)$ when $|V(G)|\le 2\chi(G)+1$. We extend this to a general ... More
Multipole Expansions of Aggregate Charge: How Far to Go?Jul 30 2015Aggregates immersed in a plasma or radiative environment will have charge distributed over their extended surface. Previous studies have modeled the aggregate charge using the monopole and dipole terms of a multipole expansion, with results indicating ... More
Evolution on a smooth landscapeJul 24 1996We study in detail a recently proposed simple discrete model for evolution on smooth landscapes. An asymptotic solution of this model for long times is constructed. We find that the dynamics of the population are governed by correlation functions that ... More
Gravity Modes Reveal the Internal Rotation of a Post-mass Transfer Gamma Doradus/Delta Scuti Hybrid Pulsator in Kepler Eclipsing Binary KIC 9592855Apr 12 2017Oct 31 2017We report the discovery of a post-mass transfer Gamma Doradus/Delta Scuti hybrid pulsator in the eclipsing binary KIC~9592855. This binary has a circular orbit, an orbital period of 1.2 days, and contains two stars of almost identical masses ($M_1=1.72M_{\odot}, ... More
Supporting Online Material for "Strong Interactions in Multimode Random Lasers"May 29 2008This preprint contains the Supporting Online Material for our paper ''Strong Interactions in Multimode Random Lasers'', Science 320, 643 (2008) (also available at: arXiv:0805.4496).
Heisenberg model in a random field: phase diagram and tricritical behaviorMar 19 2002By using the differential operator technique and the effective field theory scheme we study the tricritical behavior of Heisenberg classical model of spin-1/2 in a random field. The phase diagram in the T-h plane on a square and simple cubic lattice for ... More
Optical SETI Observations of the Anomalous Star KIC 8462852Dec 08 2015To explore the hypothesis that KIC 8462852's aperiodic dimming is caused by artificial megastructures in orbit (Wright et al. 2015), rather than a natural cause such as cometary fragments in a highly elliptical orbit (Marengo et al. 2015), we searched ... More
The Effect of a Chameleon Scalar Field on the Cosmic Microwave BackgroundJul 15 2009Sep 12 2009We show that a direct coupling between a chameleon-like scalar field and photons can give rise to a modified Sunyaev-Zel'dovich (SZ) effect in the Cosmic Microwave Background (CMB). The coupling induces a mixing between chameleon particles and the CMB ... More
On adiabatic turn-on and the asymptotic limit in linear response theory for open systemsJul 09 1993Linear response theory for open (infinite) systems leads to an expression for the current response which contains surface terms in addition to the usual bulk Kubo term. We show that this surface term vanishes identically if the correct order of limits ... More
Morphing of Geometric Composites via Residual SwellingApr 12 2015May 30 2015Understanding and controlling the shape of thin, soft objects has been the focus of significant research efforts among physicists, biologists, and engineers in the last decade. These studies aim to utilize advanced materials in novel, adaptive ways such ... More
Synthetic Observations of the HI Line in SPH-Simulated Spiral GalaxiesSep 01 2009Using the radiative transfer code Torus, we produce spectral-line cubes of the predicted HI profile from global SPH simulations of spiral galaxies. Torus grids the SPH galaxy using Adaptive Mesh Refinement, then applies a ray-tracing method to infer the ... More
Sub-THz complex dielectric constants of montmorillionite clay thin samples with Na$^{+}$/Ca$^{++}$-ionsFeb 13 2015We implement a technique to characterize electromagnetic properties at frequencies 100 to 165 GHz (3 cm$^{-1}$ to 4.95 cm$^{-1}$) of oriented montmorillionite samples using an open cavity resonator connected to a sub-millimeter wave VNA (Vector Network ... More
Current noise enhancement: channel mixing and possible nonequilibrium phonon backaction in atomic-scale Au junctionsOct 05 2016We report measurements of the bias dependence of the Fano factor in ensembles of atomic-scale Au junctions at 77 K. Previous measurements of shot noise at room temperature and low biases have found good agreement of the Fano factor with the expectations ... More
On the non-existence of elements of Kervaire invariant oneAug 26 2009May 25 2015We show that Kervaire invariant one elements in the homotopy groups of spheres exist only in dimensions at most 126. By Browder's Theorem, this means that smooth framed manifolds of Kervaire invariant one exist only in dimensions 2, 6, 14, 30, 62, and ... More
Enumeration schemes for vincular patternsAug 12 2011Jan 16 2012We extend the notion of an enumeration scheme developed by Zeilberger and Vatter to the case of vincular patterns (also called "generalized patterns" or "dashed patterns"). In particular we provide an algorithm which takes in as input a set $B$ of vincular ... More
Pattern avoidance by even permutationsJun 18 2011We study questions of even-Wilf-equivalence, the analogue of Wilf-equivalence when attention is restricted to pattern avoidance by permutations in the alternating group. Although some Wilf-equivalence results break when considering even-Wilf-equivalence ... More
Multistable Kirigami for Tunable Architected MaterialsJul 17 2018Nov 20 2018In nature, materials such as ferroelastics and multiferroics can switch their microstructure in response to external stimuli, and this reconfiguration causes a simultaneous modulation of its material properties. Rapid prototyping technologies have enabled ... More
Extended Lubrication Theory: Improved Estimates of Flow in Channels with Variable GeometryMar 10 2014Jan 27 2017Lubrication theory is broadly applicable to the flow characterization of thin fluid films and the motion of particles near surfaces. We offer an extension to lubrication theory by starting with Stokes equations and considering higher-order terms in a ... More
X-ray Fluorescent Fe Kalpha Lines from Stellar PhotospheresOct 02 2007X-ray spectra from stellar coronae are reprocessed by the underlying photosphere through scattering and photoionization events. While reprocessed X-ray spectra reaching a distant observer are at a flux level of only a few percent of that of the corona ... More
Steady-state Ab Initio Laser Theory: Generalizations and Analytic ResultsAug 03 2010Oct 13 2010We improve the steady-state ab initio laser theory (SALT) of Tureci et al. by expressing its fundamental self-consistent equation in a basis set of threshold constant flux states that contains the exact threshold lasing mode. For cavities with non-uniform ... More
Theory of the spatial structure of non-linear lasing modesOct 09 2006A self-consistent integral equation is formulated and solved iteratively which determines the steady-state lasing modes of open multi-mode lasers. These modes are naturally decomposed in terms of frequency dependent biorthogonal modes of a linear wave ... More
PT-symmetry breaking and laser-absorber modes in optical scattering systemsAug 30 2010Jan 27 2011Using a scattering matrix formalism, we derive the general scattering properties of optical structures that are symmetric under a combination of parity and time-reversal (PT). We demonstrate the existence of a transition beween PT-symmetric scattering ... More
Chaotic dust dynamics and implications for the hemispherical color asymmetries of the Uranian satellitesJun 17 2013Dust grains generated by the Uranian irregular satellites will undergo chaotic large-amplitude eccentricity oscillations under the simultaneous action of radiation forces and the highly misaligned quadrupole potentials of the oblate planet and distant ... More
PlaTIBART: a Platform for Transactive IoT Blockchain Applications with Repeatable TestingSep 27 2017Sep 30 2017With the advent of blockchain-enabled IoT applications, there is an increased need for related software patterns, middleware concepts, and testing practices to ensure adequate quality and productivity. IoT and blockchain each provide different design ... More
KnightCap: A chess program that learns by combining TD(lambda) with game-tree searchJan 10 1999In this paper we present TDLeaf(lambda), a variation on the TD(lambda) algorithm that enables it to be used in conjunction with game-tree search. We present some experiments in which our chess program ``KnightCap'' used TDLeaf(lambda) to learn its evaluation ... More
TDLeaf(lambda): Combining Temporal Difference Learning with Game-Tree SearchJan 05 1999In this paper we present TDLeaf(lambda), a variation on the TD(lambda) algorithm that enables it to be used in conjunction with minimax search. We present some experiments in both chess and backgammon which demonstrate its utility and provide comparisons ... More
Automatic Generation of Theorems and Proofs on Enumerating Consecutive-Wilf classesJan 20 2011This article, dedicated to Herbert Saul Wilf on the occaison of his forthcoming 80-th birthday, describes two complementary approaches to enumeration, the "positive" and the "negative", each with its advantages and disadvantages. Both approaches are amenable ... More
Stopping time convergence for processes associated with Dirichlet formsMay 27 2017Jun 29 2017Convergence is proved for solutions of Dirichlet problems in regions with many small excluded sets (holes), as the holes become smaller and more numerous. The problem is formulated in the context of Markov processes associated with general Dirichlet forms, ... More
Abundant stable gauge field hair for black holes in anti-de Sitter spaceAug 17 2007Jan 08 2008We present new hairy black hole solutions of su(N) Einstein-Yang-Mills theory (EYM) in asymptotically anti-de Sitter (adS) space. These black holes are described by N+1 independent parameters, and have N-1 independent gauge field degrees of freedom. Solutions ... More
Spitzer Observations of CO2 Ice Towards Field Stars in the Taurus Molecular CloudMay 17 2005We present the first Spitzer Infrared Spectrograph observations of the 15.2 micron bending mode of CO2 ice towards field stars behind a quiescent dark cloud. CO2 ice is detected towards 2 field stars (Elias 16, Elias 3) and a single protostar (HL Tau) ... More
The evolution of galaxy formationDec 01 2011Our history of understanding galaxy formation could be traced through the development of individual ideas. A cynic might be tempted to suggest that new catchphrases are developed at a faster rate than genuine progress is made.
CMB ANISOTROPIES: AN OVERVIEWFeb 02 1995A brief outline of the current status of CMB anisotropies and what they might mean, heavily biased towards the perspective of Berkeley theorists. Based on a talk presented at the 17th Texas Symposium on Relativistic Astrophysics held in Munich, December ... More
Scaling limits of Markov branching trees and Galton-Watson trees conditioned on the number of vertices with out-degree in a given setMay 12 2011Sep 22 2013We generalize recent results of Haas and Miermont to obtain scaling limits of Markov branching trees whose size is specified by the number of nodes whose out-degree lies in a given set. We then show that this implies that the scaling limit of finite variance ... More
Explicit points on the Legendre curve IIIJun 25 2014Nov 24 2014We continue our study of the Legendre elliptic curve y^2=x(x+1)(x+t) over function fields K_d=F_p(\mu_d,t^{1/d}). When d=p^f+1, we have previously exhibited explicit points generating a subgroup V_d of E(K_d) of rank d-2 and of finite, p-power index. ... More
Many-anyon trial statesAug 17 2016The problem of bounding the (abelian) many-anyon ground-state energy from above, with a dependence on the statistics parameter which matches that of currently available lower bounds, is reduced to studying the correlation functions of Moore-Read (Pfaffian) ... More