Results for "Andrew D. Bagdanov"

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Sparse Radial Sampling LBP for Writer IdentificationApr 23 2015In this paper we present the use of Sparse Radial Sampling Local Binary Patterns, a variant of Local Binary Patterns (LBP) for text-as-texture classification. By adapting and extending the standard LBP operator to the particularities of text we get a ... More
On-the-fly Network Pruning for Object DetectionMay 11 2016Object detection with deep neural networks is often performed by passing a few thousand candidate bounding boxes through a deep neural network for each image. These bounding boxes are highly correlated since they originate from the same image. In this ... More
Rotate your Networks: Better Weight Consolidation and Less Catastrophic ForgettingFeb 08 2018In this paper we propose an approach to avoiding catastrophic forgetting in sequential task learning scenarios. Our technique is based on a network reparameterization that approximately diagonalizes the Fisher Information Matrix of the network parameters. ... More
Review on Computer Vision Techniques in Emergency SituationAug 24 2017In emergency situations, actions that save lives and limit the impact of hazards are crucial. In order to act, situational awareness is needed to decide what to do. Geolocalized photos and video of the situations as they evolve can be crucial in better ... More
Improving Text Proposals for Scene Images with Fully Convolutional NetworksFeb 16 2017Text Proposals have emerged as a class-dependent version of object proposals - efficient approaches to reduce the search space of possible text object locations in an image. Combined with strong word classifiers, text proposals currently yield top state ... More
Visual Script and Language IdentificationJan 08 2016In this paper we introduce a script identification method based on hand-crafted texture features and an artificial neural network. The proposed pipeline achieves near state-of-the-art performance for script identification of video-text and state-of-the-art ... More
The asymptotic density of dead ends in non-amenable groupsJun 20 2010We show that, in non-amenable groups, the density of elements of depth at least $d$ goes to $0$ exponentially in $d$.
A stronger result on fractional strong colouringsSep 30 2010Oct 09 2014Aharoni, Berger and Ziv recently proved the fractional relaxation of the strong colouring conjecture. In this note we generalize their result as follows. Let $k\geq 1$ and partition the vertices of a graph $G$ into sets $V_1,..., V_r$, such that for $1\leq ... More
Large Cardinals and Definable Well-Orderings of the UniverseNov 16 2007We use a reverse Easton forcing iteration to obtain a universe with a definable well-ordering, while preserving the GCH and proper classes of a variety of very large cardinals. This is achieved by coding using the principle diamond star at a proper class ... More
Boundedness of Maximal Operators of Schrödinger Type with Complex TimeJun 16 2011Jun 25 2012Results of P. Sj\"olin and F. Soria on the Schr\"odinger maximal operator with complex-valued time are improved by determining up to the endpoint the sharp $s \geq 0$ for which boundedness from the Sobolev space $H^s(\mathbb{R})$ into $L^2(\mathbb{R})$ ... More
Hitting all maximum cliques with a stable set using lopsided independent transversalsNov 09 2009Mar 10 2010Rabern recently proved that any graph with omega >= (3/4)(Delta+1) contains a stable set meeting all maximum cliques. We strengthen this result, proving that such a stable set exists for any graph with omega > (2/3)(Delta+1). This is tight, i.e. the inequality ... More
The Progenitors of Subluminous Type Ia SupernovaeMay 15 2001We find that spectroscopically peculiar subluminous SNe Ia come from an old population. Of the sixteen subluminous SNe Ia known, ten are found in E/S0 galaxies, and the remainder are found in early-type spirals. The probability that this is a chance occurrence ... More
Analysis of the forward and backward in time pair-separation PDFs for inertial particles in isotropic turbulenceNov 29 2016In this paper we investigate, using theory and Direct Numerical Simulations (DNS), the Forward In Time (FIT) and Backward In Time (BIT) Probability Density Functions (PDFs) of the separation of inertial particle-pairs in isotropic turbulence. In agreement ... More
Strongly t-logarithmic t-generating sets: Geometric properties of some soluble groupsAug 20 2008We introduce the concept of a strongly t-logarithmic t-generating set for a Z[t,t^{-1}]-module, which enables us to prove that a large class of soluble groups are not almost convex. We also prove some results about dead-end depth.
Type Ia Supernovae as Stellar Endpoints and Cosmological ToolsNov 01 2010Jun 14 2011Empirically, Type Ia supernovae are the most useful, precise, and mature tools for determining astronomical distances. Acting as calibrated candles they revealed the presence of dark energy and are being used to measure its properties. However, the nature ... More
Are we ready for spray-on carbon nanotubes?Jun 05 2016Earlier this year, British sculptor, Anish Kapoor was given exclusive rights to use a new spray-on carbon nanotube-based paint. The material, produced by UK-based Surrey NanoSystems and marketed as Vantablack S-VIS, can be applied to a range of surfaces, ... More
Fractional Quantum Hall Physics in Jaynes-Cummings-Hubbard LatticesFeb 23 2012Jaynes-Cummings-Hubbard arrays provide unique opportunities for quantum emulation as they exhibit convenient state preparation and measurement, and in-situ tuning of parameters. We show how to realise strongly correlated states of light in Jaynes-Cummings-Hubbard ... More
Pairs of valuations and the geometry of soluble groupsJul 31 2009We introduce the concepts of a pair of valuations and a good generating set and show how they can be used to prove geometric properties of soluble groups.
Small u_kappa and large 2^kappa for supercompact kappaJun 19 2012In a recent preprint, Garti and Shelah state that the techniques of a paper of Dzamonja and Shelah can be used to force u_kappa to be kappa^+ for supercompact kappa with 2^kappa arbitrarily large. In this expository article we spell out the details of ... More
Indestructibility of Vopenka's PrincipleMar 24 2010We show that Vopenka's Principle and Vopenka cardinals are indestructible under reverse Easton forcing iterations of increasingly directed-closed partial orders, without the need for any preparatory forcing. As a consequence, we are able to prove the ... More
Developments and difficulties in predicting the relative velocities of inertial particles at the small-scales of turbulenceSep 13 2016In this paper, we use our recently developed theory for the backward-in-time (BIT) relative dispersion of inertial particles in turbulence (Bragg \emph{et al.}, Phys. Fluids 28, 013305, 2016) to develop the theoretical model by Pan \& Padoan (J. Fluid ... More
Pointwise Convergence of Dyadic Partial Sums of Almost Periodic Fourier SeriesDec 19 2011It is a classical result that dyadic partial sums of the Fourier series of functions $f \in L^p(\mathbb{T})$ converge almost everywhere for $p \in (1, \infty)$. In 1968, E. A. Bredihina established an analogous result for functions belonging to the Stepanov ... More
Novel growth mechanism of epitaxial graphene on metalsNov 22 2010Graphene, a hexagonal sheet of $sp^2$-bonded carbon atoms, has extraordinary properties which hold immense promise for future nanoelectronic applications. Unfortunately, the popular preparation methods of micromechanical cleavage and chemical exfoliation ... More
Dark State Adiabatic Passage with spin-one particlesFeb 19 2014Jul 14 2014Adiabatic transport of information is a widely invoked resource in connection with quantum information processing and distribution. The study of adiabatic transport via spin-half chains or clusters is standard in the literature, while in practice the ... More
Threshold and Flavour Effects in the Renormalization Group Equations of the MSSM II: Dimensionful couplingsOct 31 2008Sep 04 2010We re-examine the one-loop renormalization group equations (RGEs) for the dimensionful parameters of the minimal supersymmetric Standard Model with broken supersymmetry, allowing for arbitrary flavour structure of the soft SUSY breaking (SSB) parameters. ... More
Current-induced switching in single ferromagnetic layer nanopillar junctionsNov 07 2005Current induced magnetization dynamics in asymmetric Cu/Co/Cu single magnetic layer nanopillars has been studied experimentally at room temperature and in low magnetic fields applied perpendicular to the thin film plane. In sub-100 nm junctions produced ... More
de Sitter space from M-theory?Feb 22 2001Feb 26 2001In this note we study a massive IIA supergravity theory obtained in hep-th/9707139 by compactification of M-theory. We point out that de Sitter space in arbitrary dimensions arises naturally as the vacuum of this theory. This explicitly shows how de Sitter ... More
Zero-Branes, Quantum Mechanics and the Cosmological ConstantJul 04 2001Jul 25 2001We analyse some dynamical issues in a modified type IIA supergravity, recently proposed as an extension of M-theory that admits de Sitter space. In particular we find that this theory has multiple zero-brane solutions. This suggests a microscopic quantum ... More
Mathematical models for geometric control theoryDec 23 2013Jun 13 2014Just as an explicit parameterisation of system dynamics by state, i.e., a choice of coordinates, can impede the identification of general structure, so it is too with an explicit parameterisation of system dynamics by control. However, such explicit and ... More
Nonparametric Functional Calibration of Computer ModelsFeb 19 2016Standard methods in computer model calibration treat the calibration parameters as constant throughout the domain of control inputs. In many applications, systematic variation may cause the best values for the calibration parameters to change between ... More
Fine-tuning favors mixed axion/axino cold dark matter over neutralinos in the minimal supergravity modelOct 02 2009May 21 2010Over almost all of minimal supergravity (mSUGRA or CMSSM) model parameter space, there is a large overabundance of neutralino cold dark matter (CDM). We find that the allowed regions of mSUGRA parameter space which match the measured abundance of CDM ... More
Validating a Web Service Security Abstraction by TypingDec 10 2004An XML web service is, to a first approximation, an RPC service in which requests and responses are encoded in XML as SOAP envelopes, and transported over HTTP. We consider the problem of authenticating requests and responses at the SOAP-level, rather ... More
Bounding the fractional chromatic number of $K_Δ$-free graphsJun 11 2012Mar 30 2013King, Lu, and Peng recently proved that for $\Delta\geq 4$, any $K_\Delta$-free graph with maximum degree $\Delta$ has fractional chromatic number at most $\Delta-\tfrac{2}{67}$ unless it is isomorphic to $C_5\boxtimes K_2$ or $C_8^2$. Using a different ... More
The No-U-Turn Sampler: Adaptively Setting Path Lengths in Hamiltonian Monte CarloNov 18 2011Hamiltonian Monte Carlo (HMC) is a Markov chain Monte Carlo (MCMC) algorithm that avoids the random walk behavior and sensitivity to correlated parameters that plague many MCMC methods by taking a series of steps informed by first-order gradient information. ... More
The thermodynamics of general anesthesiaOct 19 2006It is known that the action of general anesthetics is proportional to their partition coefficient in lipid membranes (Meyer-Overton rule). This solubility is, however, directly related to the depression of the temperature of the melting transition found ... More
Possible associated signal with GW150914 in the LIGO dataSep 27 2016We present a simple method for the identification of weak signals associated with gravitational wave events. Its application reveals a signal with the same time lag as the GW150914 event in the released LIGO strain data with a significance around $3.2\sigma$. ... More
Quantum Interference and Inelastic Scattering in a Model Which-Way DeviceSep 09 2002Sep 09 2002A which-way device is one which is designed to detect which of 2 paths is taken by a quantum particle, whether Schr\"odinger's cat is dead or alive. One possible such device is represented by an Aharonov-Bohm ring with a quantum dot on one branch. A charged ... More
Transport via a Quantum ShuttleSep 09 2002We investigate the effect of quantisation of vibrational modes on a system in which the transport path is through a quantum dot mounted on a cantilever or spring such that tunnelling to and from the dot is modulated by the oscillation. We consider here ... More
Optimal antithickenings of claw-free trigraphsOct 24 2011Aug 30 2012Chudnovsky and Seymour's structure theorem for claw-free graphs has led to a multitude of recent results that exploit two structural operations: {\em compositions of strips} and {\em thickenings}. In this paper we consider the latter, proving that every ... More
An Exploration of the Approximation of Derivative Functions via Finite DifferencesJun 08 2010Finite differences have been widely used in mathematical theory as well as in scientific and engineering computations. These concepts are constantly mentioned in calculus. Most frequently-used difference formulas provide excellent approximations to various ... More
Modeling partitioning of Min proteins between daughter cells after septation in Escherichia coliJun 15 2007Jul 16 2007Ongoing sub-cellular oscillation of Min proteins is required to block minicelling in E. coli. Experimentally, Min oscillations are seen in newly divided cells and no minicells are produced. In model Min systems many daughter cells do not oscillate following ... More
Asymptotics of the chromatic number for quasi-line graphsFeb 03 2011As proved by Kahn, the chromatic number and fractional chromatic number of a line graph agree asymptotically. That is, for any line graph $G$ we have $\chi(G) \leq (1+o(1))\chi_f(G)$. We extend this result to quasi-line graphs, an important subclass of ... More
Threshold and Flavour Effects in the Renormalization Group Equations of the MSSM I: Dimensionless CouplingsDec 18 2007Sep 04 2010In a theory with broken supersymmetry, gaugino couplings renormalize differently from gauge couplings, as do higgsino couplings from Higgs boson couplings. As a result, we expect the gauge (Higgs boson) couplings and the corresponding gaugino (higgsino) ... More
On the action potential as a propagating density pulse and the role of anestheticsOct 16 2006Oct 19 2006The Hodgkin-Huxley model of nerve pulse propagation relies on ion currents through specific resistors called ion channels. We discuss a number of classical thermodynamic findings on nerves that are not contained in this classical theory. Particularly ... More
What's the value in more moments?May 11 2016The moment-based non-parametric species richness estimator of Chao is one of the most widely used estimators for the number of unobserved species in a sampling experiment. This is due in large part to its simplicity and robustness. This simplicity can ... More
Invariance of certain plurigenera for surfaces in mixed characteristicsSep 27 2016We prove the deformation invariance of Kodaira dimension and of certain plurigenera for log surfaces which are smooth over a DVR.
Pattern formation inside bacteria: fluctuations due to low copy number of proteinsFeb 20 2003We examine fluctuation effects due to the low copy number of proteins involved in pattern-forming dynamics within a bacterium. We focus on a stochastic model of the oscillating MinCDE protein system regulating accurate cell division in E. coli. We find ... More
Persistence Amplitudes from Numerical Quantum GravityDec 09 1997The Euclidean quantum amplitude to go between data specified on an initial and a final hypersurface may be approximated by the tree amplitude exp(-I_{classical}/\hbar), where I_{classical} is the Euclidean action of the classical solution joining the ... More
Signatures of QCD Matter at RHICSep 04 1998We discuss possible experimental signatures of forming a Quark-Gluon plasma in high energy nuclear collisions. In first order phase transitions such as the chiral symmetry restoration supercooling may lead to density fluctuations such as droplet formation ... More
Tilted torus magnetic fields in neutron stars and their gravitational wave signaturesOct 28 2013Gravitational-wave diagnostics are developed for discriminating between varieties of mixed poloidal-toroidal magnetic fields in neutron stars, with particular emphasis on differentially rotating protoneutron stars. It is shown that tilted torus magnetic ... More
A superlocal version of Reed's ConjectureAug 26 2012Nov 15 2014Reed's well-known $\omega$, $\Delta$, $\chi$ conjecture proposes that every graph satisfies $\chi \leq \lceil \frac 12(\Delta+1+\omega)\rceil$. The second author formulated a {\em local strengthening} of this conjecture that considers a bound supplied ... More
MACHOs in a Flattened HaloApr 26 1993If massive compact halo objects (\ms) are detected in ongoing searches, then \tsmctlmc, the ratio of the optical depth toward the Small and Large Magellanic Clouds, will be a robust indicator of the flattening of the Galactic dark matter halo. For a spherical ... More
Pixel Lensing Search For Bright Microlensing Events and Variables in the Galactic BulgeJul 04 1997We describe a new method to search for gravitational microlensing toward the Galactic bulge that employs a small camera rather than a conventional telescope and probes new regions of parameter space. The small aperture (~65 mm) permits detection of stellar ... More
Statistics of trajectories in two-state master equationsDec 02 2008Feb 23 2009We derive a simple expression for the probability of trajectories of a master equation. The expression is particularly useful when the number of states is small and permits the calculation of observables that can be defined as functionals of whole trajectories. ... More
Estimating the number of species to attain sufficient representation in a random sampleJul 11 2016Aug 19 2016The statistical problem of using an initial sample to estimate the number of unique species in a larger sample has found important applications in fields far removed from ecology. Here we address the general problem of estimating the number of species ... More
Diffusion of Asymmetric SwimmersFeb 19 2003Particles moving along curved trajectories will diffuse if the curvature fluctuates sufficiently in either magnitude or orientation. We consider particles moving at a constant speed with either a fixed or with a Gaussian distributed curvature magnitude. ... More
Inferring selective constraint from population genomic data suggests recent regulatory turnover in the human brainSep 10 2013Nov 22 2015The comparative genomics revolution of the past decade has enabled the discovery of functional elements in the human genome via sequence comparison. While that is so, an important class of elements, those specific to humans, is entirely missed by searching ... More
Virialization of high redshift dark matter haloesJul 23 2010Jun 03 2011We present results of a study of the virial state of high redshift dark matter haloes in an N-body simulation. We find that the majority of collapsed, bound haloes are not virialized at any redshift slice in our study ($z=15-6$) and have excess kinetic ... More
Robust Models for Phase Shifts in Accreting Binary StarsAug 02 2007Radial velocity studies of accreting binary stars commonly use accretion disk emission lines to determine the radial velocity of the primary star and therefore the mass ratio. These emission line radial velocity curves are often shifted in phase from ... More
Neutralino versus axion/axino cold dark matter in the 19 parameter SUGRA modelMay 12 2010Sep 15 2010We calculate the relic abundance of thermally produced neutralino cold dark matter in the general 19 parameter supergravity (SUGRA-19) model. A scan over GUT scale parameters reveals that models with a bino-like neutralino typically give rise to a dark ... More
Mainly axion cold dark matter in the minimal supergravity modelJun 15 2009Aug 12 2009We examine the minimal supergravity (mSUGRA) model under the assumption that the strong CP problem is solved by the Peccei-Quinn mechanism. In this case, the relic dark matter (DM) abundance consists of three components: {\it i}). cold axions, {\it ii}). ... More
What is special about water as a matrix of life?Jan 24 2007Water offers a large temperature domain of stable liquid, and the characteristic hydrophobic effects are first a consequence of the temperature insensitivity of equation-of-state features of the aqueous medium, compared to other liquids. On this basis, ... More
Classification of bicovariant differential calculi on the Jordanian quantum groups GL_{g,h}(2) and SL_{h}(2) and quantum Lie algebrasFeb 17 1998Feb 18 1998We classify all 4-dimensional first order bicovariant calculi on the Jordanian quantum group GL_{h,g}(2) and all 3-dimensional first order bicovariant calculi on the Jordanian quantum group SL_{h}(2). In both cases we assume that the bicovariant bimodules ... More
Twisting 2-cocycles for the construction of new non-standard quantum groupsFeb 24 1997May 19 1997We introduce a new class of 2-cocycles defined explicitly on the generators of certain multiparameter standard quantum groups. These allow us, through the process of twisting the familiar standard quantum groups, to generate new as well as previously ... More
Geometrogenesis under Quantum Graphity: problems with the ripening UniverseJun 25 2015Quantum Graphity (QG) is a model of emergent geometry in which space is represented by a dynamical graph. The graph evolves under the action of a Hamiltonian from a high-energy pre-geometric state to a low-energy state in which geometry emerges as a coarse-grained ... More
Digital three-state adiabatic passageMar 28 2013May 17 2013We explore protocols for three-state adiabatic passage where the tunnel matrix elements are varied digitally, rather than smoothly as is the case with conventional adiabatic passage. In particular, we focus on the STIRAP and related three-state schemes ... More
Regression on a GraphNov 10 2009The `Signal plus Noise' model for nonparametric regression can be extended to the case of observations taken at the vertices of a graph. This model includes many familiar regression problems. This article discusses the use of the edges of a graph to measure ... More
Eroding dipoles and vorticity growth for Euler flows in $ \scriptstyle{\mathbb{R}}^3$ I. Axisymmetric flow without swirlDec 24 2015A review of analyses based upon anti-parallel vortex structures suggests that structurally stable vortex structures with eroding circulation may offer a path to the study of rapid vorticity growth in solutions of Euler's equations in $ \scriptstyle{\mathbb{R}}^3$. ... More
The unbounded dead-end depth property is not a group invariantApr 06 2005Sep 12 2005The dead-end depth of an element g of a group with finite generating set A is the distance from g to the complement of the radius d(1,g) closed ball, in the word metric d associated to A. We exhibit a finitely presented group K with two finite generating ... More
Aharonov-Bohm oscillations in disordered nanorings with quantum dots: Effect of electron-electron interactionsMay 13 2009May 15 2009We investigate the effect of electron-electron interactions on Aharonov-Bohm (AB) current oscillations in nanorings formed by a chain of metallic quantum dots. We demonstrate that electron-electron interactions cause electron dephasing thereby suppressing ... More
Reconciling cyanobacterial fixed-nitrogen distributions and transport experiments with quantitative modellingDec 14 2011Filamentous cyanobacteria growing in media with insufficient fixed nitrogen differentiate some cells into heterocysts, which fix nitrogen for the remaining vegetative cells. Transport studies have shown both periplasmic and cytoplasmic connections between ... More
Limit theorems for random spatial drainage networksJan 21 2009Suppose that under the action of gravity, liquid drains through the unit $d$-cube via a minimal-length network of channels constrained to pass through random sites and to flow with nonnegative component in one of the canonical orthogonal basis directions ... More
Graph states as ground states of two-body frustration-free HamiltoniansMar 10 2014Jul 10 2014The framework of measurement-based quantum computation (MBQC) allows us to view the ground states of local Hamiltonians as potential resources for universal quantum computation. A central goal in this field is to find models with ground states that are ... More
The dependency of boosted tagging algorithms on the event colour structureJul 25 2012The impact of event colour structure on the performance of the Johns-Hopkins, CMS, HEPToptagger and N-Subjettiness algorithms is investigated by studying colour singlet and colour octet resonances decaying to top-quark pairs. Large differences in top-tagging ... More
Finding a smallest odd hole in a claw-free graph using global structureMar 31 2011May 24 2011A lemma of Fouquet implies that a claw-free graph contains an induced $C_5$, contains no odd hole, or is quasi-line. In this paper we use this result to give an improved shortest-odd-hole algorithm for claw-free graphs by exploiting the structural relationship ... More
Extracting and Verifying Cryptographic Models from C Protocol Code by Symbolic ExecutionJul 06 2011Consider the problem of verifying security properties of a cryptographic protocol coded in C. We propose an automatic solution that needs neither a pre-existing protocol description nor manual annotation of source code. First, symbolically execute the ... More
Energetics of the Quantum Graphity UniverseSep 09 2014Quantum graphity is a background independent model for emergent geometry, in which space is represented as a complete graph. The high-energy pre-geometric starting point of the model is usually considered to be the complete graph, however we also consider ... More
4U2206+54 - an Unusual High Mass X-ray Binary with a 9.6 Day Orbital Period but No Strong PulsationsJul 06 2001Rossi X-ray Timing Explorer All-Sky Monitor observations of the X-ray source 4U2206+54, previously proposed to be a Be star system, show the X-ray flux to be modulated with a period of approximately 9.6 days. If the modulation is due to orbital variability ... More
The Orbital Period of the Be/Neutron Star Binary RX J0812.4-3114Dec 15 1999We present the results of Rossi X-ray Timing Explorer observations of the Be star X-ray binary system RX J0812.4-3114. A light curve obtained with the RXTE All-Sky Monitor shows that the source is currently in an active state with outbursts occurring ... More
Dark state adiabatic passage with branched networks and high-spin systems: spin separation and entanglementJun 03 2015Adiabatic methods are potentially important for quantum information protocols because of their robustness against many sources of technical and fundamental noise. They are particularly useful for quantum transport, and in some cases elementary quantum ... More
Counting cocircuits and convex two-colourings is #P-completeOct 11 2008We prove that the problem of counting the number of colourings of the vertices of a graph with at most two colours, such that the colour classes induce connected subgraphs is #P-complete. We also show that the closely related problem of counting the number ... More
Claw-free graphs, skeletal graphs, and a stronger conjecture on $ω$, $Δ$, and $χ$Dec 13 2012The second author's $\omega$, $\Delta$, $\chi$ conjecture proposes that every graph satisties $\chi \leq \lceil \frac 12 (\Delta+1+\omega)\rceil$. In this paper we prove that the conjecture holds for all claw-free graphs. Our approach uses the structure ... More
A short proof that $χ$ can be bounded $ε$ away from $Δ+1$ towards $ω$Nov 06 2012In 1998 the second author proved that there is an $\epsilon>0$ such that every graph satisfies $\chi \leq \lceil (1-\epsilon)(\Delta+1)+\epsilon\omega\rceil$. The first author recently proved that any graph satisfying $\omega > \frac 23(\Delta+1)$ contains ... More
Properties of Gamma-Ray Burst Time Profiles Using Pulse Decomposition AnalysisFeb 10 2000The time profiles of many gamma-ray bursts consist of distinct pulses, which offers the possibility of characterizing the temporal structure of these bursts using a relatively small set of pulse shape parameters. This pulse decomposition analysis has ... More
SNLS: Overview and High-z SpectroscopyOct 25 2004The Supernova Legacy Survey (SNLS; will discover and obtain g'r'i'z' lightcurves for more than 700 spectroscopically confirmed SNe Ia (0.3<z<0.9) to differentiate between competing models for Dark Energy. We fit the multicolor ... More
Annular Spin-Transfer Memory ElementJul 09 2009An annular magnetic memory that uses a spin-polarized current to switch the magnetization direction or helicity of a magnetic region is proposed. The device has magnetic materials in the shape of a ring (1 to 5 nm in thickness, 20 to 250 nm in mean radius ... More
Fluctuations of persistent currentFeb 16 2010Nov 19 2010We theoretically analyze equilibrium fluctuations of persistent current (PC) in nanorings. We demonstrate that these fluctuations persist down to zero temperature provided the current operator does not commute with the total Hamiltonian of the system. ... More
Acoustically tuneable optical transmission through a subwavelength hole with a bubbleOct 15 2016Efficient manipulation of light with sound in subwavelength-sized volumes is important for applications in photonics, phononics and biophysics, but remains elusive. We theoretically demonstrate the control of light with MHz-range ultrasound in a subwavelength, ... More
Quantum Phase Slip NoiseMar 03 2016Quantum phase slips (QPS) generate voltage fluctuations in superconducting nanowires. Employing Keldysh technique and making use of the phase-charge duality arguments we develop a theory of QPS-induced voltage noise in such nanowires. We demonstrate that ... More
Persistent current noise in normal and superconducting nanoringsDec 03 2012We investigate fluctuations of persistent current (PC) in nanorings both with and without dissipation and decoherence. We demonstrate that such PC fluctuations may persist down to zero temperature provided there exists either interaction with an external ... More
The quandary of quandles: The Borel completeness of a knot invariantFeb 09 2016The isomorphism type of the knot quandle introduced by Joyce is a complete invariant of tame knots. Whether two quandles are isomorphic is in practice difficult to determine; we show that this question is provably hard: isomorphism of quandles is Borel ... More
Looking Down the Light Cone: Can Deep Redshift Surveys Alone Measure the Power Spectrum?Feb 20 1998We analyze the window functions for the spherical harmonic mode estimators of all--sky, volume limited surveys considering evolutionary effects along the past light--cone which include the deviation of the distance scale from a linear relationship with ... More
On the total length of the random minimal directed spanning treeSep 13 2004In Bhatt and Roy's minimal directed spanning tree (MDST) construction for a random partially ordered set of points in the unit square,all edges must respect the ``coordinatewise'' partial order and there must be a directed path from each vertex to a minimal ... More
Price of Asymptotic SafetyJan 25 2018All known examples of 4d quantum field theories with asymptotic freedom or asymptotic safety at weak coupling involve non-abelian gauge interactions. We demonstrate that this is not a coincidence: no weakly coupled fixed points, ultraviolet or otherwise, ... More
Optical spin-1 chain and its use as a quantum computational wireApr 21 2010Jul 26 2010Measurement-based quantum computing, a powerful alternative to the standard circuit model, proceeds using only local adaptive measurements on a highly-entangled resource state of many spins on a graph or lattice. Along with the canonical cluster state, ... More
Discovering functional DNA elements using population genomic information: A proof of concept using human mtDNAFeb 07 2014Identifying the complete set of functional elements within the human genome would be a windfall for multiple areas of biological research including medicine, molecular biology, and evolution. Complete knowledge of function would aid in the prioritization ... More
Fast and Accurate Coarsening Simulation with an Unconditionally Stable Time StepAug 08 2003We present Cahn-Hilliard and Allen-Cahn numerical integration algorithms that are unconditionally stable and so provide significantly faster accuracy-controlled simulation. Our stability analysis is based on Eyre's theorem and unconditional von Neumann ... More
A new formulation of protein evolutionary models that account for structural constraintsAug 20 2013Dec 02 2013Despite the importance of a thermodynamically stable structure with a conserved fold for protein function, almost all evolutionary models neglect site-site correlations that arise from physical interactions between neighboring amino acid sites. This is ... More
Subcompact cardinals, squares, and stationary reflectionJun 13 2011Feb 23 2012We generalise Jensen's result on the incompatibility of subcompactness with square. We show that alpha^+-subcompactness of some cardinal less than or equal to alpha precludes square_alpha, but also that square may be forced to hold everywhere where this ... More
RXTE Observations of the Be star X-ray Transient X0726-260 (4U0728-25) - Orbital and Pulse PeriodsAug 26 1997Rossi X-ray Timing Explorer (RXTE) All Sky Monitor observations of the transient Be star X-ray source X0726-260 suggest a 34.5 day period. This is apparently confirmed by a serendipitous RXTE Proportional Counter Array (PCA) slew detection of the source ... More