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Results for "Carolyn Kierans"

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Looking Under a Better Lamppost: MeV-scale Dark Matter CandidatesMar 14 2019The era of precision cosmology has revealed that about 85% of the matter in the universe is dark matter. Two well-motivated candidates are weakly interacting massive particles (WIMPs) and weakly interacting sub-eV particles (WISPs) (e.g. axions). Both ... More
A Repeated Signal Difference for Recognising PatternsApr 18 2016Sep 07 2016This paper describes a new mechanism that might help with defining pattern sequences, by the fact that it can produce an upper bound on the ensemble value that can persistently oscillate with the actual values produced from each pattern. With every firing ... More
In Praise of Sequence (Co-)Algebra and its implementation in HaskellDec 14 2018What is Sequence Algebra? This is a question that any teacher or student of mathematics or computer science can engage with. Sequences are in Calculus, Combinatorics, Statistics and Computation. They are foundational, a step up from number arithmetic. ... More
A Metric for Modelling and Measuring Complex Behavioural SystemsMar 04 2014This paper describes a metric for measuring the success of a complex system composed of agents performing autonomous behaviours. Because of the difficulty in evaluating such systems, this metric will help to give an initial indication as to how suitable ... More
Standardized network reconstruction of CHO cell metabolismApr 09 2013We have created a genome-scale network reconstruction of chinese hamster ovary (CHO) cell metabolism. Existing reconstructions were improved in terms of annotation standards, to facilitate their subsequent use in dynamic modelling. The resultant network ... More
New Ideas for Brain ModellingMar 05 2014Oct 17 2016This paper describes some biologically-inspired processes that could be used to build the sort of networks that we associate with the human brain. New to this paper, a 'refined' neuron will be proposed. This is a group of neurons that by joining together ... More
One lump or two?Oct 12 2012We investigate methods for modelling metabolism within populations of cells. Typically one represents the interaction of a cloned population of cells with their environment as though it were one large cell. The question is as to whether any dynamics are ... More
Geometrical Defects in Josephson Junction ArraysMar 22 1999Dislocations and disclinations in a lattice of Josephson junctions will affect the dynamics of vortex excitations within the array. These defects effectively distort the space in which the excitations move and interact. The interaction energy between ... More
An ergodic theorem for non-singular actions of the Heisenberg groupsFeb 14 2017We show that there is a sequence of subsets of each discrete Heisenberg group for which the non-singular ergodic theorem holds. The sequence depends only on the group; it works for any of its non-singular actions. To do this we use a metric which was ... More
The slices of $S^n \wedge H\underline{\mathbb{Z}}$ for cyclic $p$-groupsOct 07 2015The slice filtration is a filtration of equivariant spectra. While the tower is analogous to the Postnikov tower in the nonequivariant setting, complete slice towers are known for relatively few $G$-spectra. In this paper, we determine the slice tower ... More
The (n)-solvable filtration of the link concordance group and Milnor's invariantsNov 07 2012We establish several new results about both the (n)-solvable filtration, F_n^m, of the set of link concordance classes and the (n)-solvable filtration of the string link concordance group. We first establish a relationship between Milnor's invariants ... More
New Ideas for Brain Modelling 3Nov 22 2016This paper considers a process for the creation and subsequent firing of sequences of neuronal patterns, as might be found in the human brain. The scale is one of larger patterns emerging from an ensemble mass, possibly through some type of energy equation ... More
In Praise of Sequence (Co-)Algebra and its implementation in HaskellDec 14 2018Feb 28 2019What is Sequence Algebra? This is a question that any teacher or student of mathematics or computer science can engage with. Sequences are in Calculus, Combinatorics, Statistics and Computation. They are foundational, a step up from number arithmetic. ... More
Polarization transitions in interacting ring 1D arraysMay 02 2006Periodic nanostructures can display the dynamics of arrays of atoms while enabling the tuning of interactions in ways not normally possible in Nature. We examine one dimensional arrays of a ``synthetic atom,'' a one dimensional ring with a nearest neighbor ... More
Anisotropic Transport of Quantum Hall Meron-Pair ExcitationsJan 30 1997Double-layer quantum Hall systems at total filling factor $\nu_T=1$ can exhibit a commensurate-incommensurate phase transition driven by a magnetic field $B_{\parallel}$ oriented parallel to the layers. Within the commensurate phase, the lowest charge ... More
Localization of eigenvector centrality in networks with a cut vertexSep 04 2018Jan 10 2019We show that eigenvector centrality exhibits localization phenomena on networks that can be easily partitioned by the removal of a vertex cut set, the most extreme example being networks with a cut vertex. Three distinct types of localization are identified ... More
Dual double EPW-sextics and their periodsMay 03 2006A locally complete family of projective symplectic 4-folds is provided by natural double covers of Eisenbud-Popescu-Walter (EPW) sextic hypersurfaces in projective 5-space. The dual of an EPW sextic is another EPW sextic, thus to a double EPW sextic X ... More
Higher-dimensional analogues of K3 surfacesMay 18 2010In the first part we survey some of the known results and conjectures on compact Hyperkaehler (HK) manifolds. In the second part we presents a program which aims to show that HK four-folds whose second cohomology (with 4-tuple cup-product) is isomorphic ... More
A new six dimensional irreducible symplectic varietyOct 19 2000By results of the author there exists a projective (holomorphic) symplectic desingularization of the moduli space of rank-two torsion-free sheaves on a genus-two Jacobian with $c_1=0$ and $c_2=2$. This desingularization has a natural map to the self-product ... More
Geodesic Conjugacy in two-step nilmanifoldsMar 15 1995Two Riemannian manifolds are said to have $C^k$-conjugate geodesic flows if there exist an $C^k$ diffeomorphism between their unit tangent bundles which intertwines the geodesic flows. We obtain a number of rigidity results for the geodesic flows on compact ... More
The Moduli Space of Three Dimensional Lie AlgebrasOct 10 2005In this paper, we consider the versal deformations of three dimensional Lie algebras. We classify Lie algebras and study their deformations by using linear algebra techniques to study the cohomology. We will focus on how the deformations glue the space ... More
The weight-two Hodge structure of moduli spaces of sheaves on a K3 surfaceOct 02 1995We prove that the weight-two Hodge structure of moduli spaces of torsion-free sheaves on a K3 surface is as described by Mukai (the rank is arbitrary but we assume the first Chern class is primitive). We prove the moduli space is an irreducible symplectic ... More
Irreducible symplectic 4-folds numerically equivalent to Hilb^2(K3)Apr 21 2005Jul 19 2005First steps towards a classification of irreducible symplectic 4-folds whose integral 2-cohomology with 4-tuple cup product is isomorphic to that of Hilb^2(K3). We prove that any such 4-fold deforms to an irreducible symplectic 4-fold of Type A or Type ... More
A class of 2-groups admitting an action of the symmetric group of degree 3Jan 02 2013Jan 22 2013A biextraspecial group of rank $m$ is an extension of a special 2-group $Q$ of the form $2^{2 + 2m}$ by $L\cong L_2(2)$, such that the 3-element from $L$ acts on $Q$ fixed-point-freely. Subgroups of this type appear in at least the sporadic groups $J_2$, ... More
Pairwise incident planes and hyperkaehler four-foldsApr 27 2012We address the following question: what are the cardinalities of maximal finite families of pairwise incident planes in a complex projective space? One proves easily that the span of the planes has dimension 5 or 6. Up to projectivities there is one such ... More
Periods of Double EPW-sexticsMar 29 2012Jul 20 2014We study the indeterminacy locus of the period map for double EPW-sextics. We recall that double EPW-sextics are parametrized by lagrangian subspaces of the third wedge-product of a 6-dimensional complex vector-space. The indeterminacy locus is contained ... More
Reflections on Shannon Information: In search of a natural information-entropy for imagesSep 05 2016It is not obvious how to extend Shannon's original information entropy to higher dimensions, and many different approaches have been tried. We replace the English text symbol sequence originally used to illustrate the theory by a discrete, bandlimited ... More
Polarization transitions in quantum ring arraysDec 05 2003We calculate the zero temperature electrostatic properties of charged one and two dimensional arrays of rings, in the classical and quantum limits. Each ring is assumed to be an ideal ring of negligible width, with exactly one electron on the ring that ... More
Desingularized moduli spaces of sheaves on a K3, IAug 06 1997May 22 1998Moduli spaces of semistable torsion-free sheaves on a K3 surface $X$ are often holomorphic symplectic varieties, deformation equivalent to a Hilbert scheme parametrizing zero-dimensional subschemes of $X$. In fact this should hold whenever semistability ... More
Continuous Families of Isophasal Scattering ManifoldsNov 04 2002We construct continuous families of scattering manifolds with the same scattering phase. The manifolds are compactly supported metric perturbations of Euclidean $\mathbf{R}^{n}$ for $n\geq8$. The metric perturbation may have arbitrarily small support. ... More
Internally $4$-connected binary matroids with every element in three trianglesAug 21 2016Let $M$ be an internally $4$-connected binary matroid with every element in three triangles. Then $M$ has at least four elements $e$ such that si$(M/e)$ is internally 4-connected.
The Klein four slices of positive suspensions of HF_2Aug 16 2018Aug 28 2018We describe the slices of positive integral suspensions of the equivariant Eilenberg-Mac Lane spectrum HF_2 for the constant Mackey functor over the Klein four-group $C_2\times C_2$.
Actions of small cancellation groups on hyperbolic spacesJul 27 2018Jul 30 2018We generalize Gruber--Sisto's construction of the coned--off graph of a small cancellation group to build a partially ordered set $\mathcal{TC}$ of cobounded actions of a given small cancellation group whose smallest element is the action on the Gruber--Sisto ... More
Moduli of vector-bundles on surfacesSep 20 1996This is a survey paper: we discuss certain recent results, with some improvements. It will appear in the S. Cruz proceedings.
Theoretical Comparison of Rashba Spin-Orbit Coupling in Digitally, Discretely, and Continuously Alloyed NanostructuresMay 09 2011Although most theoretical calculations of quantum wells with non-square profiles assume that material composition is varied continuously, it is more common in experiment to grow digital alloys. We compare the Rashba spin-orbit interaction of triangular ... More
Desingularized moduli spaces of sheaves on a K3, IIMay 22 1998In preprint alg-geom/9708009 we have constructed a (ten-dimensional) symplectic desingularization of the moduli space of rank-two torsion-free semistable sheaves on a $K3$, with trivial determinant and second Chern class equal to 4. In the present paper ... More
Property $P_{naive}$ for acylindrically hyperbolic groupsOct 13 2016We prove that every acylindrically hyperbolic group that has no non-trivial finite normal subgroup satisfies a strong ping pong property, the $P_{naive}$ property: for any finite collection of elements $h_1, \dots, h_k$, there exists another element $\gamma\neq ... More
Positron Annihilation in the GalaxyMar 13 2019The 511 keV line from positron annihilation in the Galaxy was the first $\gamma$-ray line detected to originate from outside our solar system. Going into the fifth decade since the discovery, the source of positrons is still unconfirmed and remains one ... More
Isospectral potentials and conformally equivalent isospectral metrics on spheres, balls and Lie groupsSep 27 2002Nov 18 2002We construct pairs of conformally equivalent isospectral Riemannian metrics $\phi_1 g$ and $\phi_2 g$ on spheres $S^n$ and balls $B^{n+1}$ for certain dimensions $n$, the smallest of which is $n=7$, and on certain compact simple Lie groups. In the case ... More
Limits To Certainty in QoS Pricing and BandwidthOct 03 2001Advanced services require more reliable bandwidth than currently provided by the Internet Protocol, even with the reliability enhancements provided by TCP. More reliable bandwidth will be provided through QoS (quality of service), as currently discussed ... More
The geometry of generalized loxodromic elementsFeb 09 2018We explore geometric conditions which ensure a given element of a finitely generated group is, or fails to be, generalized loxodromic; as part of this we prove a generalization of Sisto's result that every generalized loxodromic element is Morse. We provide ... More
Metabolic scaling law for fetus and placentaJun 12 2008We present a version of Kleiber's scaling law for fetus and placenta.
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
Stratification of patient trajectories using covariate latent variable modelsOct 27 2016Standard models assign disease progression to discrete categories or stages based on well-characterized clinical markers. However, such a system is potentially at odds with our understanding of the underlying biology, which in highly complex systems may ... More
Non-singular $\mathbb{Z}^d$-actions: an ergodic theorem over rectangles with application to the critical dimensionsJun 06 2016We adapt techniques of Hochman to prove a non-singular ergodic theorem for $\mathbb{Z}^d$-actions where the sums are over rectangles with side lengths increasing at arbitrary rates, and in particular are not necessarily balls of a norm. This result is ... More
Evaporative Cooling in Semiconductor DevicesMay 02 2006We discuss the theory of cooling electrons in solid-state devices via ``evaporative emission.'' Our model is based on filtering electron subbands in a quantum-wire device. When incident electrons in a higher-energy subband scatter out of the initial electron ... More
R-matrix theory for nanoscale phonon thermal transport across devices and interfacesSep 19 2011We have adapted R-matrix theory to calculate phonon scattering across systems of molecular to mesoscopic scale. The key novelty of this work is that the only required information about the scattering region are its normal modes, which are evaluated only ... More
Isospectral deformations of negatively curved Riemannian manifolds with boundary which are not locally isometricMar 01 2000To what extent does the eigenvalue spectrum of the Laplace-Beltrami operator on a compact Riemannian manifold determine the geometry of the manifold? We give examples of isospectral manifolds with different local geometry including continuous families ... More
Limits on deviations from the inverse-square law on megaparsec scalesApr 06 2004Jun 29 2005We present an attempt to constrain deviations from the gravitational inverse-square law on large-scale structure scales. A perturbed law modifies the Poisson equation, which implies a scale-dependent growth of overdensities in the linear regime and thus ... More
From Neutron Star Observables to the Equation of State: An Optimal ParametrizationMay 11 2016The increasing number and precision of measurements of neutron star masses, radii, and, in the near future, moments of inertia offer the possibility of precisely determining the neutron star equation of state. One way to facilitate the mapping of observables ... More
Determining optimal factors for chemical synthesis of pharmaceutical products using experimental dataFeb 03 2016In a chemical synthesis process to manufacture a pharmaceutical product, an initial set of substances evolve according to chemical reactions, under certain process conditions, into a series of new substances. One of these substances is a target pharmaceutical ... More
Revisiting the deconfinement phase transition in SU(4) Yang-Mills theory in 2+1 dimensionsDec 07 2007Apr 04 2008In order to deepen our understanding of the nature of the deconfinement phase transition for various gauge groups, we investigate SU(4) Yang-Mills theory in 2+1 dimensions. We find that the transition is weakly first order. We perform extensive Monte ... More
On the Crossing Numbers of Cartesian Products of Small Graphs with Paths, Cycles and StarsFeb 21 2019There has been significant research dedicated towards computing the crossing numbers of families of graphs resulting from the Cartesian products of small graphs with arbitrarily large paths, cycles and stars. For graphs with four or fewer vertices, these ... More
Boundary volume and length spectra of Riemannian manifolds: What the middle degree Hodge spectrum doesn't revealNov 02 2001Jul 16 2003Let $M$ be a $2m$-dimensional compact Riemannian manifold. We show that the spectrum of the Hodge Laplacian acting on $m$-forms does not determine whether the manifold has boundary, nor does it determine the lengths of the closed geodesics. Among the ... More
Neural correlates of self-generated imagery and cognition throughout the sleep cycleOct 06 2016Humans have been aware for thousands of years that sleep comes in many forms, accompanied by different kinds of mental content. We review the first-person report literature on the frequency and type of content experienced in various stages of sleep, showing ... More
Message passing and moment closure for susceptible-infected-recovered epidemics on finite networksSep 14 2013Feb 25 2014The message passing approach of Karrer and Newman [Phys. Rev. E 82, 016101 (2010)] is an exact and practicable representation of susceptible-infected-recovered dynamics on finite trees. Here we show that, assuming Poisson contact processes, a pair-based ... More
On the Crossing Numbers of Cartesian Products of Small Graphs with Paths, Cycles and StarsFeb 21 2019Feb 27 2019There has been significant research dedicated towards computing the crossing numbers of families of graphs resulting from the Cartesian products of small graphs with arbitrarily large paths, cycles and stars. For graphs with four or fewer vertices, these ... More
Double Longitudinal Spin Asymmetry in Neutral Pion Production in Polarized p+p Collisions at sqrt(s)=200 GeV at PHENIXJan 26 2007A major goal of the RHIC spin program is to measure \Delta g, the gluon contribution to the proton's spin. Measurements by PHENIX of the double longitudinal spin asymmetry, A_LL, of the neutral pion production at mid-rapidity in polarized proton collisions ... More
Recovering the Lie algebra from its extremal geometryOct 22 2014An element $x$ of a Lie algebra $L$ over the field $F$ is extremal if $[x,[x,L]]=Fx$. Under minor assumptions, it is known that, for a simple Lie algebra $L$, the extremal geometry ${\cal{E}}(L)$ is a subspace of the projective geometry of $L$ and either ... More
Line of Dirac Nodes in Hyper-Honeycomb LatticesAug 23 2014Jul 09 2015We propose a family of free fermion lattice models that have "Dirac loops", closed lines of Dirac nodes in momentum space, on which the density of states vanishes linearly with energy. Those lattices all possess the planar trigonal connectivity present ... More
Size Dependent Growth in Metabolic NetworksOct 09 2012Accurately determining and classifying the structure of complex networks is the focus of much current research. One class of network of particular interest are metabolic pathways, which have previously been studied from a graph theoretical viewpoint in ... More
An Exact Relationship Between Invasion Probability and Endemic Prevalence for Markovian SIS Dynamics on NetworksFeb 01 2013Aug 01 2013Understanding models which represent the invasion of network-based systems by infectious agents can give important insights into many real-world situations, including the prevention and control of infectious diseases and computer viruses. Here we consider ... More
Sequential measurements: Busch-Gleason theorem and its applicationsApr 24 2017Probabilities enter quantum mechanics via Born's rule, the uniqueness of which was proven by Gleason. Busch subsequently relaxed the assumptions of this proof, expanding its domain of applicability in the process. Extending this work to sequential measurement ... More
Data Clustering and Graph Partitioning via Simulated MixingMar 15 2016Spectral clustering approaches have led to well-accepted algorithms for finding accurate clusters in a given dataset. However, their application to large-scale datasets has been hindered by computational complexity of eigenvalue decompositions. Several ... More
Reasoning about effects: from lists to cyber-physical agentsJan 24 2018Theories for reasoning about programs with effects initially focused on basic manipulation of lists and other mutable data. The next challenge was to consider higher-order programming, adding functions as first class objects to mutable data. Reasoning ... More
Geodesic Orbit Riemannian Structures on $\mathbf{R}^n$Mar 02 2018Sep 26 2018A geodesic orbit manifold is a complete Riemannian manifold all of whose geodesics are orbits of one-parameter groups of isometries. We give both a geometric and an algebraic characterization of geodesic orbit manifolds that are diffeomorphic to $\mathbf{R}^n$. ... More
A Component-oriented Framework for Autonomous AgentsJul 31 2017The design of a complex system warrants a compositional methodology, i.e., composing simple components to obtain a larger system that exhibits their collective behavior in a meaningful way. We propose an automaton-based paradigm for compositional design ... More
Effect of Strong Disorder on 3-Dimensional Chiral Topological Insulators: Phase Diagrams, Maps of the Bulk Invariant and Existence of Topological Extended Bulk StatesAug 11 2014The effect of strong disorder on chiral-symmetric 3-dimensional lattice models is investigated via analytical and numerical methods. The phase diagrams of the models are computed using the non-commutative winding number, as functions of disorder strength ... More
New homogeneous Einstein metrics of negative Ricci curvatureAug 17 1999We construct new homogeneous Einstein spaces with negative Ricci curvature in two ways: First, we give a method for classifying and constructing a class of rank one Einstein solvmanifolds whose derived algebras are two-step nilpotent. As an application, ... More
Cyclic Orbit Codes and Stabilizer SubfieldsMar 05 2014Cyclic orbit codes are constant dimension subspace codes that arise as the orbit of a cyclic subgroup of the general linear group acting on subspaces in the given ambient space. With the aid of the largest subfield over which the given subspace is a vector ... More
Inductive tools for connected ribbon graphs, delta-matroids and multimatroidsFeb 23 2017Mar 08 2017We prove a splitter theorem for tight multimatroids, generalizing the corresponding result for matroids, obtained independently by Brylawski and Seymour. Further corollaries give splitter theorems for delta-matroids and ribbon graphs.
Towards a splitter theorem for internally 4-connected binary matroids VIII: small matroidsJan 01 2015Jul 12 2016Our splitter theorem for internally 4-connected binary matroids studies pairs of the form (M,N), where N and M are internally 4-connected binary matroids, M has a proper N-minor, and if M' is an internally 4-connected matroid such that M has a proper ... More
Finite-temperature extension for cold neutron star equations of stateFeb 27 2019Observations of isolated neutron stars place constraints on the equation of state (EOS) of cold, neutron-rich matter, while nuclear physics experiments probe the EOS of hot, symmetric matter. Many dynamical phenomena, such as core-collapse supernovae, ... More
Towards a splitter theorem for internally 4-connected binary matroids IIJun 20 2012Let M and N be internally 4-connected binary matroids such that M has a proper N-minor, and |E(N)| is at least seven. As part of our project to develop a splitter theorem for internally 4-connected binary matroids, we prove the following result: if M\e ... More
Einstein solvmanifolds have maximal symmetryJul 29 2015All known examples of homogeneous Einstein metrics of negative Ricci curvature can be realized as left-invariant Riemannian metrics on solvable Lie groups. After defining a notion of maximal symmetry among left-invariant Riemannian metrics on a Lie group, ... More
Towards the Automated Verification of Cyber-Physical Security Protocols: Bounding the Number of Timed IntrudersMay 27 2016Timed Intruder Models have been proposed for the verification of Cyber-Physical Security Protocols (CPSP) amending the traditional Dolev-Yao intruder to obey the physical restrictions of the environment. Since to learn a message, a Timed Intruder needs ... More
Spectral isolation of naturally reductive metrics on simple Lie groupsJul 05 2007Jun 28 2010We show that within the class of left-invariant naturally reductive metrics $\mathcal{M}_{\operatorname{Nat}}(G)$ on a compact simple Lie group $G$, every metric is spectrally isolated. We also observe that any collection of isospectral compact symmetric ... More
Hyperbolic structures on groupsOct 14 2017Nov 17 2018For every group $G$, we introduce the set of hyperbolic structures on $G$, denoted $\mathcal{H}(G)$, which consists of equivalence classes of (possibly infinite) generating sets of $G$ such that the corresponding Cayley graph is hyperbolic; two generating ... More
Neutral Pion Double Longitudinal Spin Asymmetry in Proton-Proton Collisions at sqrt(s)=200 GeV Using the PHENIX DetectorJun 04 2006New results from polarized p-p collisions at sqrt(s)=200 GeV of double longitudinal spin asymmetry in pi0 production using the PHENIX detector in the 2005 RHIC run are presented. Both positive and negative maximal gluon polarization scenarios are inconsistent ... More
The Reverse of The Law of Large NumbersMar 27 2008The Law of Large Numbers tells us that as the sample size (N) is increased, the sample mean converges on the population mean, provided that the latter exists. In this paper, we investigate the opposite effect: keeping the sample size fixed while increasing ... More
Goldstone mode kink-solitons in double layer quantum Hall systemsNov 15 2002It is shown that in charge unbalanced double layer quantum Hall system with zero tunneling pseudospin Goldstone mode excitations form moving kink-soliton in weakly nonlinear limit. This charge-density localization moves with a velocity of gapless linear ... More
Complete hierarchies of SIR models on arbitrary networks with exact and approximate moment closureJan 26 2015Apr 24 2015We first generalise ideas discussed by Kiss et al. (2015) to prove a theorem for generating exact closures (here expressing joint probabilities in terms of their constituent marginal probabilities) for susceptible-infectious-removed (SIR) dynamics on ... More
A survey of graphs with known or bounded crossing numbersJan 16 2019Jan 31 2019We present, to the best of the authors' knowledge, all known results for the crossing numbers of specific graphs and graph families. The results are separated into various categories; specifically, results for general graph families, results for graphs ... More
A survey of graphs with known or bounded crossing numbersJan 16 2019Feb 15 2019We present, to the best of the authors' knowledge, all known results for the (planar) crossing numbers of specific graphs and graph families. The results are separated into various categories; specifically, results for general graph families, results ... More
An effective crossing minimisation heuristic based on star insertionApr 26 2018Feb 15 2019We present a new heuristic method for minimising crossings in a graph. The method is based upon repeatedly solving the so-called {\em star insertion problem} in the setting where the combinatorial embedding is fixed, and has several desirable characteristics ... More
Giga-z: A 100,000 Object Superconducting Spectrophotometer for LSST Follow-upJul 18 2013We simulate the performance of a new type of instrument, a Superconducting Multi-Object Spectrograph (SuperMOS), that uses Microwave Kinetic Inductance Detectors (MKIDs). MKIDs, a new detector technology, feature good QE in the UVOIR, can count individual ... More
Kink-antikink collisions in the phi^6 modelJan 31 2011Feb 15 2011We study kink-antikink collisions in the one-dimensional non-integrable scalar phi^6 model. Although the single-kink solutions for this model do not possess an internal vibrational mode, our simulations reveal a resonant scattering structure, thereby ... More
Nearly conformal gauge theories in finite volumeJul 27 2009We report new results on nearly conformal gauge theories with fermions in the fundamental representation of the SU(3) color gauge group as the number of fermion flavors is varied in the Nf = 4-16 range. To unambiguously identify the chirally broken phase ... More
New Higgs physics from the latticeOct 16 2007We report the first results from our comprehensive lattice tool set to explore non-perturbative aspects of Higgs physics in the Standard Model. We demonstrate in Higgs-Yukawa models that Higgs mass lower bounds and upper bounds can be determined in lattice ... More
Adding Context to Concept TreesJun 17 2016Concept Trees are a type of database that can organise arbitrary textual information using a very simple rule. Each tree tries to represent a single cohesive concept and the trees can link with each other for navigation and semantic purposes. The trees ... More
Striking a balance with Recon 2.1Nov 22 2013Nov 26 2014Recon 2 is a highly curated reconstruction of the human metabolic network. Whilst the network is state of the art, it has shortcomings, including the presence of unbalanced reactions involving generic metabolites. By replacing these generic molecules ... More
Massive skyrmions in quantum Hall ferromagnetsMay 11 2000Nov 16 2000We apply the theory of elasticity to study the effects of skyrmion mass on lattice dynamics in quantum Hall systems. We find that massive Skyrme lattices behave like a Wigner crystal in the presence of a uniform perpendicular magnetic field. We make a ... More
Edges control clustering in levitated granular matterJan 24 2019The properties of small clusters depend dramatically on the interactions between their constituent particles. However, it remains challenging to design and tune the interactions between macroscopic particles, such as in a granular material. Here, we use ... More
On the Hurwitz action in finite Coxeter groupsDec 15 2015We provide a necessary and sufficient condition on an element of a finite Coxeter group to ensure the transitivity of the Hurwitz action on its set of reduced decompositions into products of reflections. We show that this action is transitive if and only ... More
Maximum Fidelity Retransmission of Mirror Symmetric Qubit StatesSep 25 2002In this paper we address the problem of optimal reconstruction of a quantum state from the result of a single measurement when the original quantum state is known to be a member of some specified set. A suitable figure of merit for this process is the ... More
N-opcode Analysis for Android Malware Classification and CategorizationJul 27 2016Malware detection is a growing problem particularly on the Android mobile platform due to its increasing popularity and accessibility to numerous third party app markets. This has also been made worse by the increasingly sophisticated detection avoidance ... More
Methods for approximating stochastic evolutionary dynamics on graphsFeb 18 2019Population structure can have a significant effect on evolution. For some systems with sufficient symmetry, analytic results can be derived within the mathematical framework of evolutionary graph theory which relate to the outcome of the evolutionary ... More
Machine Learning CICY ThreefoldsJun 08 2018Jul 31 2018The latest techniques from Neural Networks and Support Vector Machines (SVM) are used to investigate geometric properties of Complete Intersection Calabi-Yau (CICY) threefolds, a class of manifolds that facilitate string model building. An advanced neural ... More
Density-Matrix Renormalization Group study of Many-Body Localization in Floquet EigenstatesAug 23 2016We generalize the recently introduced Density-Matrix Renormalization Group (DMRG-X) [Khemani et al, PRL 2016] algorithm to obtain Floquet eigenstates of one-dimensional, periodically driven many-body localized systems. This generalization is made possible ... More
Reducing estimation bias in adaptively changing monitoring networks with preferential site selectionDec 03 2014This paper explores the topic of preferential sampling, specifically situations where monitoring sites in environmental networks are preferentially located by the designers. This means the data arising from such networks may not accurately characterize ... More