Results for "Ruth Misener"

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Design of Experiments for Model Discrimination Hybridising Analytical and Data-Driven ApproachesFeb 12 2018Healthcare companies must submit pharmaceutical drugs or medical devices to regulatory bodies before marketing new technology. Regulatory bodies frequently require transparent and interpretable computational modelling to justify a new healthcare technology, ... More
Design of Experiments for Model Discrimination Hybridising Analytical and Data-Driven ApproachesFeb 12 2018May 31 2018Healthcare companies must submit pharmaceutical drugs or medical devices to regulatory bodies before marketing new technology. Regulatory bodies frequently require transparent and interpretable computational modelling to justify a new healthcare technology, ... More
Data-driven optimization of processes with degrading equipmentOct 22 2018Jan 24 2019In chemical and manufacturing processes, unit failures due to equipment degradation can lead to process downtime and significant costs. In this context, finding an optimal maintenance strategy to ensure good unit health while avoiding excessive expensive ... More
GPdoemd: a Python package for design of experiments for model discriminationOct 05 2018Jan 14 2019Model discrimination identifies a mathematical model that usefully explains and predicts a given system's behaviour. Researchers will often have several models, i.e.\ hypotheses, about an underlying system mechanism, but insufficient experimental data ... More
Bayesian Optimization with Dimension Scheduling: Application to Biological SystemsNov 17 2015Bayesian Optimization (BO) is a data-efficient method for global black-box optimization of an expensive-to-evaluate fitness function. BO typically assumes that computation cost of BO is cheap, but experiments are time consuming or costly. In practice, ... More
Physics of Cosmic Microwave Background anisotropies and primordial fluctuationsSep 17 2001The physics of the origin and evolution of CMB anisotropies is described. I explain the idea and status of cosmic parameter estimation and follow it up with critical comments on its dependence on model assumptions and initial conditions.
Gauge Invariant Cosmological Perturbation TheoryNov 17 1993After an introduction to the problem of cosmological structure formation, we develop gauge invariant cosmological perturbation theory. We derive the first order perturbation equations of Einstein's equations and energy momentum ``conservation''. Furthermore, ... More
A New Construction of Isospectral Riemannian Nilmanifolds with ExamplesFeb 10 1995We present a new construction for obtaining pairs of higher-step isospectral Riemannian nilmanifolds and compare several resulting new examples. In particular, we present new examples of manifolds that are isospectral on functions, but not isospectral ... More
Braneworld black holesApr 16 2008In these lectures, I give an introduction to and overview of braneworlds and black holes in the context of warped compactifications. I first describe the general paradigm of braneworlds, and introduce the Randall-Sundrum model. I discuss braneworld gravity, ... More
What do we really know about Dark Energy?Mar 28 2011Sep 25 2011In this paper I discuss what we truly know about dark energy. I shall argue that up to date our single indication for the existence of dark energy comes from distance measurements and their relation to redshift. Supernovae, CMB anisotropies and observations ... More
Rigidity of cosmic acceleration in a class of k-essence cosmologiesOct 05 2004We study the structural stability of a cosmic acceleration (inflation) in a class of k-essence cosmologies against changes in the shape of the potential. Those models may be viewed as generalized tachyon cosmologies and this analysis extends previous ... More
Thick ideals in equivariant and motivic stable homotopy categoriesMar 29 2015We study thick ideals in the stable motivic homotopy category SH(k) and in its subcategories of compact and of finite cellular objects. If k is a subfield of the complex or even the real numbers, then using comparison functors we find thick ideals corresponding ... More
Continuous Families of Riemannian manifolds, isospectral on functions but not on 1-formsFeb 13 1997The purpose of this paper is to present the first continuous families of Riemannian manifolds isospectral on functions but not on 1-forms, and simultaneously, the first continuous families of Riemannian manifolds with the same marked length spectrum but ... More
The Marked Length Spectrum vs. The Laplace Spectrum on Forms on Riemannian NilmanifoldsOct 05 1995The subject of this paper is the relationship among the marked length spectrum, the length spectrum, the Laplace spectrum on functions, and the Laplace spectrum on forms on Riemannian nilmanifolds. In particular, we show that for a large class of three-step ... More
Cosmological Strucure Formation with Topological DefectsMar 23 2000Structure formation with topological defects is described. The main differences from inflationary models are highlighted. The results are compared with recent observations. It is concluded that all the defect models studied so far are in disagreement ... More
The three burials of Melquiades DGPJan 10 2008In this talk I review three fatal flaws of the DGP braneworld model, which has been put forward as a possible model for late time acceleration without a cosmological constant: Ghosts, Cosmological Crashes, and Instability of the 5D vacuum. The talk is ... More
G1 Cosmologies with Gravitational and Scalar WavesDec 18 1998I present here a new algorithm to generate families of inhomogeneous massless scalar field cosmologies. New spacetimes, having a single isometry, are generated by breaking the homogeneity of massless scalar field $G_2$ models along one direction. As an ... More
Theory of the Interaction of Planetary Nebulae with the Interstellar MediumJan 02 2000The theory of the interaction of planetary nebulae with the interstellar medium is important for the interpretation of nebular morphologies that deviate from point symmetry. It can be used to probe the interstellar medium and its magnetic field. We emphasize ... More
An introduction to right-angled Artin groupsOct 23 2006Recently, right-angled Artin groups have attracted much attention in geometric group theory. They have a rich structure of subgroups and nice algorithmic properties, and they give rise to cubical complexes with a variety of applications. This survey article ... More
Searching for HyperbolicityAug 06 2017This is an expository paper, based on by a talk given at the AWM Research Symposium 2017. It is intended as a gentle introduction to geometric group theory with a focus on the notion of hyperbolicity, a theme that has inspired the field from its inception ... More
BraneworldsJul 01 2005This course is an introduction to the physics of braneworlds. We concentrate on braneworlds with only one extra-dimension and discuss their gravity. We derive the gravitational equations on the brane from the bulk Einstein equation and explore some limits ... More
Inflating p-branesApr 30 2003We look for solutions in Einstein gravity corresponding to inflating braneworlds of arbitrary dimension and co-dimension. These solutions correspond to isolated sources (no long range fields). Using dynamical systems techniques, we show that there exists ... More
Anisotropies in the Cosmic Microwave Background: Theoretical FoundationsOct 29 1996The analysis of anisotropies in the cosmic microwave background (CMB) has become an extremely valuable tool for cosmology. We even have hopes that planned CMB anisotropy experiments may revolutionize cosmology. Together with determinations of the CMB ... More
Cosmic p-branesOct 27 1995Jan 31 1997We consider the metrics for cosmic strings and $p$-branes in spacetime dimension $N>4$, that is, we look for solutions to Einstein-Maxwell-Dilaton gravity in $N$-dimensions with boost symmetry in the $p$-directions along the brane. Focussing first in ... More
Light Deflection in Perturbed Friedmann UniversesJan 18 1994In this letter a new formula for light deflection is derived using only physically observable concepts. The general result is specialized to cosmological perturbation theory and expressed in terms of gauge--invariant perturbation variables. The resulting ... More
Early Reionization in CosmologyNov 17 1993The cosmic microwave background (CMB) anisotropies have turned out to represent one of the most stringent 'bottle necks' for scenarios of large scale structure formation. As a possibility to relax this constraint, it has been proposed that early reionization ... More
Nonsingular global string compactificationsNov 03 1999Nov 17 1999We consider an exotic `compactification' of spacetime in which there are two infinite extra dimensions, using a global string instead of a domain wall. By having a negative cosmological constant we prove the existence of a nonsingular static solution ... More
The Cosmic Microwave Background: The history of its experimental investigation and its significance for cosmologyJun 05 2015This review describes the discovery of the cosmic microwave background radiation in 1965 and its impact on cosmology in the 50 years that followed. This discovery has established the Big Bang model of the Universe and the analysis of its fluctuations ... More
Geometrical constraints on dark energy modelsOct 15 2007This contribution intends to give a pedagogical introduction to the topic of dark energy (the mysterious agent supposed to drive the observed late time acceleration of the Universe) and to various observational tests which require only assumptions on ... More
The spatial structure of cell signaling systemsAug 03 2013The spatial structure of the cell is highly organized at all levels: from small complexes and assemblies, to local nano- and micro-clusters, to global, micrometer scales across and between cells. We suggest that this multiscale spatial cell organization ... More
Gravitational waves from cosmological phase transitionsFeb 08 2010I discuss the generation of a stochastic background of gravitational waves during a first order phase transition. I present simple general arguments which explain the main features of the gravitational wave spectrum like the $k^3$ power law growth on ... More
Frontiers of the Universe: What do we know, what do we understand?May 07 2002In this talk I summarize the topics addressed during the conference. We have discussed the most relevant cosmological observations of the last say 10 years and their implications for our understanding of the Universe. My finding throughout this meeting ... More
Cosmic Magnetic Fields and the CMBSep 08 2006I describe the imprint of primordial magnetic fields on the CMB. I show that these are observable only if the field amplitude is of the order of $B\gsim 10^{-9}G$ on Mpc scale. I further argue that such fields are strongly constrained by the stochastic ... More
Nonsingular global stringsJun 04 1996Oct 17 1997We examine the possibility that time dependence might remove the singular nature of global string spacetimes. We first show that this time dependence takes a specific form -- a de-Sitter like expansion along the length of the string and give an argument ... More
Global field dynamics and cosmological tructure formationNov 02 1994We discuss gravitational effects of global scalar fields and, especially, of global topological defects. We first give an introduction to the dynamics of global fields and the formation of defects. Next we investigate the induced gravitational fields, ... More
Macroscopic open strings and gravitational confinementAug 14 2002We consider classical solutions for strings ending on magnetically charged black holes in four-dimensional Kaluza-Klein theory. We examine the classical superstring and the global vortex, which can be viewed as a nonsingular model for the superstring. ... More
Clarifying perturbations in the ekpyrotic universeDec 04 2001Mar 22 2002In this note I try to clarify the problem of perturbations in the ekpyrotic universe. I write down the most general matching conditions and specify the choices taken by the two debating sides. I also bring up the problem of surface stresses which always ... More
Holographic Superconductivity with Gauss-Bonnet gravityDec 07 2010I review recent work on holographic superconductivity with Einstein-Gauss-Bonnet gravity, and show how the critical temperature of the superconductor depends on both gravitational backreaction and the Gauss-Bonnet parameter, using both analytic and numerical ... More
Loop amplitudes in gauge theories: modern analytic approachesDec 20 2010Mar 24 2011This article reviews on-shell methods for analytic computation of loop amplitudes, emphasizing techniques based on unitarity cuts. Unitarity techniques are formulated generally but have been especially useful for calculating one-loop amplitudes in massless ... More
The theory of CMB anisotropiesSep 27 2001This is a review of the theory of CMB anisotropies, an updated version of a course given at the troisieme cycle de la Suisse Romande. An introduction to gauge invariant cosmological perturbation theory is given and the theory CMB anisotropies is develiped ... More
The Gregory-Laflamme instabilityJul 28 2011I give a brief review of the Gregory-Laflamme instability as originally found for a 5-dimensional black string. This is a chapter of the book "Black Holes in Higher Dimensions" to be published by Cambridge University Press (editor: G. Horowitz)
The Marked Length Spectrum Versus the Laplace Spectrum on Forms on Riemannian NilmanifoldsOct 13 1995The subject of this paper is the relationship among the marked length spectrum, the length spectrum, the Laplace spectrum on functions, and the Laplace spectrum on forms on Riemannian nilmanifolds. In particular, we show that for a large class of three-step ... More
A Note on the Finiteness of Curvature at Cosmic String CuspsDec 05 1994We examine a Nambu-Goto string trajectory in the neighbourhood of a cusp and determine the extrinsic curvature invariants. These are demonstrated to be finite, in contradiction with naive expectation. Thus the Nambu action is a valid approximation for ... More
Cosmological perturbation theoryFeb 05 2004Sep 21 2004This is a review on cosmological perturbation theory. After an introduction, it presents the problem of gauge transformation. Gauge invariant variables are introduced and the Einstein and conservation equations are written in terms of these variables. ... More
Black string instabilities in anti-de Sitter spaceApr 13 2000Sep 25 2000We show how to extend the usual black string instability of vacuum or charged black p-branes to the anti-de Sitter background. The string fragments in an analogous fashion to the $\Lambda=0$ case, the main difference being that instead of a periodic array ... More
Signatures of Topological Defects in the Microwave Sky: An IntroductionFeb 28 1997An introduction to topological defects in cosmology is given. We discuss their possible relevance for structure formation. Especial emphasis is given on the signature of topological defects in the spectrum of anisotropies in the cosmic microwave background. ... More
Symmetries and assisted inflation in the DGP braneworld modelFeb 03 2004Oct 20 2004We present here the general transformation that leaves unchanged the form of the field equations for perfect fluid cosmologies in the DGP braneworld model. Specifically, a prescription for relating exact solutions with different equations of state is ... More
Discussion of "Multiple Testing for Exploratory Research" by J. J. Goeman and A. SolariAug 16 2012Goeman and Solari [Statist. Sci. 26 (2011) 584-597, arXiv:1208.2841] have addressed the interesting topic of multiple testing for exploratory research, and provided us with nice suggestions for exploratory analysis. They defined properties that an inferential ... More
Frobenius powers of non-complete intersectionsJun 27 2001Aug 02 2001For a commutative ring $R$ of characteristic $p$, let $\phi : R \to R$ be the Frobenius homomorphism and let $^{\phi^r}R$ denote the $R$-module structure on $R$ defined via the $r$-th power of the Frobenius. We show that the Tor functor against the Frobenius ... More
Improved Upper Bounds for the Information Rates of the Secret Sharing Schemes Induced by the Vamos MatroidSep 17 2008An access structure specifying the qualified sets of a secret sharing scheme must have information rate less than or equal to one. The Vamos matroid induces two non-isomorphic access structures V1 and V6, which were shown by Marti-Farre and Padro to have ... More
Geometric journal impact factors correcting for individual highly cited articlesOct 29 2015Journal impact factors (JIFs) are widely used and promoted but have important limitations. In particular, JIFs can be unduly influenced by individual highly cited articles and hence are inherently unstable. A logical way to reduce the impact of individual ... More
The influence of time and discipline on the magnitude of correlations between citation counts and quality scoresOct 29 2015Although various citation-based indicators are commonly used to help research evaluations, there are ongoing controversies about their value. In response, they are often correlated with quality ratings or with other quantitative indicators in order to ... More
More Precise Methods for National Research Citation Impact ComparisonsSep 21 2015Governments sometimes need to analyse sets of research papers within a field in order to monitor progress, assess the effect of recent policy changes, or identify areas of excellence. They may compare the average citation impacts of the papers by dividing ... More
SN and BAO constraints on (new) polynomial dark energy parametrizations: current results and forecastsMay 25 2011Mar 07 2012In this work we introduce two new polynomial parametrizations of dark energy and explore their correlation properties. The parameters to fit are the equation of state values at z=0 and z=0.5, which have naturally low correlation and have already been ... More
Bounds on Black Hole SpinsMar 27 2009Beam powers and black hole masses of 48 extended radio sources are combined to obtain lower bounds on the spins and magnetic field strengths of supermassive black holes. This is done in the context of the models of Blandford & Znajek (1977) (the 'BZ' ... More
Distance-based phylogenetic methods around a polytomyJul 22 2013Distance-based phylogenetic algorithms attempt to solve the NP-hard least squares phylogeny problem by mapping an arbitrary dissimilarity map representing biological data to a tree metric. The set of all dissimilarity maps is a Euclidean space properly ... More
Vector perturbations of galaxy number countsMay 19 2016Jul 21 2016We derive the contribution to relativistic galaxy number count fluctuations from vector and tensor perturbations within linear perturbation theory. Our result is consistent with the the relativistic corrections to number counts due to scalar perturbation, ... More
Interactions of cosmological gravitational waves and magnetic fieldsSep 08 2008Jan 05 2009The energy momentum tensor of a magnetic field always contains a spin-2 component in its anisotropic stress and therefore generates gravitational waves. It has been argued in the literature (Caprini & Durrer \cite{CD}) that this gravitational wave production ... More
On the growth of cocompact hyperbolic Coxeter groupsOct 21 2009Jun 23 2010For an arbitrary cocompact hyperbolic Coxeter group G with finite generator set S and complete growth function P(x)/Q(x), we provide a recursion formula for the coefficients of the denominator polynomial Q(x) which allows to determine recursively the ... More
False discovery rate controlling procedures for discrete testsDec 20 2011Jan 27 2014Benjamini and Hochberg (1995) proposed the false discovery rate (FDR) as an alternative to the family-wise error rate in multiple testing problems, and proposed a procedure to control the FDR. For discrete data this procedure may be highly conservative. ... More
Solving for tadpole coefficients in one-loop amplitudesApr 17 2009Jan 17 2011One-loop amplitudes may be expanded in a basis of scalar integrals multiplied by rational coefficients. We relate the coefficient of the one-point integral to the coefficients of higher-point integrals, by considering the effects of introducing an additional, ... More
Divergence and quasimorphisms of right-angled Artin groupsJan 20 2010Jan 26 2010We give a group theoretic characterization of geodesics with superlinear divergence in the Cayley graph of a right-angled Artin group A(G) with connected defining graph G. We use this to determine when two points in an asymptotic cone of A(G) are separated ... More
Garside structure for the braid group of G(e,e,r)Jun 11 2003We give a new presentation of the braid group $B$ of the complex reflection group $G(e,e,r)$ which is positive and homogeneous, and for which the generators map to reflections in the corresponding complex reflection group. We show that this presentation ... More
Cosmic strings in dilaton gravityJan 09 1997Jun 06 1997We examine the metric of an isolated self-gravitating abelian-Higgs vortex in dilatonic gravity for arbitrary coupling of the vortex fields to the dilaton. We look for solutions in both massless and massive dilaton gravity. We compare our results to existing ... More
The Wedderburn b-decomposition for alternative baric algebrasOct 26 2014In this paper we deal with the Wedderburn b-decomposition for alternative baric algebras.
Perturbative gauge theory and 2+2=4Apr 03 2014The group $S_4$ of permutations on four elements has an irreducible representation corresponding to the partition 4=2+2. This representation appears in several different mathematical contexts: the Jacobi identity of Lie algebras; the Schouten identity ... More
How do Range Names Hinder Novice Spreadsheet Debugging Performance?Sep 14 2010Although experts diverge on how best to improve spreadsheet quality, it is generally agreed that more time needs to be spent testing spreadsheets. Ideally, experienced and trained spreadsheet engineers would carry this out, but quite often this is neither ... More
Microwave Background Anisotropies Induced by Global Scalar Fields: The Large N LimitDec 20 1996We present an analysis of CMB anisotropies induced by global scalar fields in the large N limit. In this limit, the CMB anisotropy spectrum can be determined without cumbersome 3D simulations. We determine the source functions and their unequal time correlation ... More
Automorphisms of higher-dimensional right-angled Artin groupsSep 17 2007Jul 03 2008We study the algebraic structure of the automorphism group of a general right-angled Artin group. We show that this group is virtually torsion-free and has finite virtual cohomological dimension. This generalizes results proved by the authors and John ... More
Length functions of 2-dimensional right-angled Artin groupsMar 28 2011Apr 08 2011Morgan and Culler proved that a minimal action of a free group on a tree is determined by its translation length function. We prove an analogue of this theorem for 2-dimensional right-angled Artin groups acting on CAT(0) rectangle complexes.
A free differential Lie algebra for the intervalOct 30 2006Oct 31 2006Using geometric methods we constructively show the existence of a unique completed free differential graded Lie algebra modelled on the interval, with three generators, a, b and e in degrees -1, -1 and 0, corresponding to the two 0-cells and one 1-cell, ... More
The three smallest compact arithmetic hyperbolic 5-orbifoldsMay 14 2012We determine the three hyperbolic 5-orbifolds of smallest volume among compact arithmetic orbifolds, and we identify their fundamental groups with hyperbolic Coxeter groups. This gives two different ways to compute the volume of these orbifolds.
The product of lattice covolume and discrete series formal dimension: p-adic GL(2)Jan 31 2019Let $F$ be a nonarchimedean local field of characteristic $0$ and residue field of order not divisible by $2$. We show how to calculate the product of the covolume of a torsion-free lattice in $PGL(2,F)$ and the formal dimension of a discrete series representation ... More
Dark Energy and Modified GravityNov 25 2008Explanations of the late-time cosmic acceleration within the framework of general relativity are plagued by difficulties. General relativistic models are mostly based on a dark energy field with fine-tuned, unnatural properties. There is a great variety ... More
Recent Progress in Regge CalculusFeb 03 1997While there has been some advance in the use of Regge calculus as a tool in numerical relativity, the main progress in Regge calculus recently has been in quantum gravity. After a brief discussion of this progress, attention is focussed on two particular, ... More
Gravitational wave production: A strong constraint on primordial magnetic fieldsJun 13 2001Oct 01 2001We compute the gravity waves induced by anisotropic stresses of stochastic primordial magnetic fields. The nucleosynthesis bound on gravity waves is then used to derive a limit on the magnetic field amplitude as function of the spectral index. The obtained ... More
Kalb-Ramond axion production in anisotropic string cosmologiesMar 13 2000We compute the energy spectra for massless Kalb-Ramond axions in four-dimensional anisotropic string cosmological models. We show that, when integrated over directions, the four-dimensional anisotropic model leads to infra-red divergent spectra similar ... More
Testing Superstring Theories with Gravitational WavesMay 26 2011Oct 24 2011We provide a simple transfer function that determines the effect of an early matter dominated era on the gravitational wave background and show that a large class of compactifications of superstring theory might be tested by observations of the gravitational ... More
Microwave Background Anisotropies from Scaling Seed PerturbationsFeb 03 1997Jul 28 1997We study microwave background anisotropies induced by scaling seed perturbations in a universe dominated by cold dark matter. Using a gauge invariant linear perturbation analysis, we solve the perturbation equations on super-horizon scales, for CMB anisotropies ... More
Selection rules for splitting stringsMay 01 1997Oct 17 1997It has been pointed out that Nielsen-Olesen vortices may be able to decay by pair production of black holes. We show that when the abelian Higgs model is embedded in a larger theory, the additional fields may lead to selection rules for this process - ... More
Cosmological constraints combining H(z), CMB shift and SNIa observational dataApr 20 2007Jul 27 2007Recently H(z) data obtained from differential ages of galaxies have been proposed as a new geometrical probe of dark energy. In this paper we use those data, combined with other background tests (CMB shift and SNIa data), to constrain a set of general ... More
A new method for the Alcock-Paczynski testJun 15 2012Aug 07 2012We argue that from observations alone, only the transverse power spectrum $C_\ell(z_1,z_2)$ and the corresponding correlation function $\xi(\theta,z_1,z_2)$ can be measured and that these contain the full three dimensional information. We determine the ... More
The Effect of Heteroscedasticity on Regression TreesJun 16 2016Regression trees are becoming increasingly popular as omnibus predicting tools and as the basis of numerous modern statistical learning ensembles. Part of their popularity is their ability to create a regression prediction without ever specifying a structure ... More
Single Cut IntegrationNov 10 2010Nov 11 2010We present an analytic technique for evaluating single cuts for one-loop integrands, where exactly one propagator is taken to be on shell. Our method extends the double-cut integration formalism of one-loop amplitudes to the single-cut case. We argue ... More
Spin Properties of Supermassive Black Holes with Powerful OutflowsJan 13 2016Relationships between beam power and accretion disk luminosity are studied for a sample of 55 HERG, 13 LERG, and 29 RLQ with powerful outflows. The ratio of beam power to disk luminosity tends to be high for LERG, low for RLQ, and spans the full range ... More
Vortices and black holes in dilatonic gravityJun 25 1999Apr 11 2000We study analytically black holes pierced by a thin vortex in dilatonic gravity for an arbitrary coupling of the vortex to the dilaton in an arbitrary frame. We show that the horizon of the charged black hole supports the long-range fields of the Nielsen-Olesen ... More
Unitarity Cuts with Massive Propagators and Algebraic Expressions for CoefficientsDec 07 2006Jun 13 2007In the first part of this paper, we extend the d-dimensional unitarity cut method of hep-ph/0609191 to cases with massive propagators. We present formulas for integral reduction with which one can obtain coefficients of all pentagon, box, triangle and ... More
A new Garside structure for braid groups of type $(e,e,r)$Jan 06 2009Feb 04 2009We describe a new presentation for the complex reflection groups of type $(e,e,r)$ and their braid groups. A diagram for this presentation is proposed. The presentation is a monoid presentation which is shown to give rise to a Garside structure. A detailed ... More
Molybdenum, Ruthenium, and the Heavy r-process Elements in Moderately Metal-Poor Main-Sequence Turnoff StarsApr 03 2013The ratios of elemental abundances observed in metal-poor stars of the Galactic halo provide a unique present-day record of the nucleosynthesis products of its earliest stars. While the heaviest elements were synthesized by the r- and s-processes, dominant ... More
The Nature of the Controversy over Time-Symmetric Quantum CounterfactualsJan 22 2014It is proposed that the recent controversy over "time-symmetric quantum counterfactuals" (TSQCs), based on the Aharonov-Bergmann-Lebowitz Rule for measurements of pre- and post-selected systems, can be clarified by taking TSQCs to be counterfactuals with ... More
The $k$-Dominating GraphSep 24 2012Mar 01 2013Given a graph $G$, the $k$-dominating graph of $G$, $D_k(G)$, is defined to be the graph whose vertices correspond to the dominating sets of $G$ that have cardinality at most $k$. Two vertices in $D_k(G)$ are adjacent if and only if the corresponding ... More
On Habiro's cyclotomic expansions of the Ohtsuki invariantJan 31 2005Feb 07 2005We give a self-contained treatment of Le and Habiro's approach to the Jones function of a knot and Habiro's cyclotomic form of the Ohtsuki invariant for manifolds obtained by surgery around a knot. On the way we reproduce a state sum formula of Garoufalidis ... More
Curvature Corrections to Dynamics of Domain WallsOct 13 1994The most usual procedure for deriving curvature corrections to effective actions for topological defects is subjected to a critical reappraisal. A logically unjustified step (leading to overdetermination) is identified and rectified, taking the standard ... More
Probabilistic inference of basic stellar parameters: application to flickering starsJul 04 2016Jul 16 2016The relations between observable stellar parameters are usually assumed to be deterministic. That is, given an infinitely precise measurement of independent variable, `$x$', and some model, the value of dependent variable, `$y$' can be known exactly. ... More
Non-crossing partitions of type (e,e,r)Mar 23 2004Apr 21 2004We investigate a new lattice of generalised non-crossing partitions, constructed using the geometry of the complex reflection group $G(e,e,r)$. For the particular case $e=2$ (resp. $r=2$), our lattice coincides with the lattice of simple elements for ... More
Automorphism groups of some affine and finite type Artin groupsAug 30 2004We observe that, for each positive integer n > 2, each of the Artin groups of finite type A_n, B_n=C_n, and affine type \tilde A_{n-1} and \tilde C_{n-1} is a central extension of a finite index subgroup of the mapping class group of the (n+2)-punctured ... More
The field-of-norms functor and the Hilbert symbol for higher local fieldsOct 04 2010The field-of-norms functor is applied to deduce explicit reciprocity formulae for the Hilbert symbol in the mixed characteristic case from the explicit formula for the Witt symbol in characteristic p > 2 in the context of higher local fields. Is is shown ... More
Gauge-Transformation Properties of Cosmological Observables and its Application to the Light-Cone AverageMay 16 2017Sep 12 2017Theoretical descriptions of observable quantities in cosmological perturbation theory should be independent of coordinate systems. This statement is often referred to as gauge-invariance of observable quantities, and the sanity of their theoretical description ... More
Massive particles and unitarity cutsFeb 11 2012We present an extension of the spinor integration formalism of one loop amplitudes from the double-cut to the single-cut case. This technique can be applied for the computation of the tadpole coefficients. Moreover we describe an off-shell continuation ... More
Estimates of Black Hole Spin Properties of 55 SourcesMar 04 2011Studies of black hole spin and other parameters as a function of redshift provide information about the physical state and merger and accretion histories of the systems. One way that black hole spin may be estimated is through observations of extended ... More