Results for "J. Thompson"

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A criterion for topological entropy to decrease under normalised Ricci flowNov 16 2009Dec 18 2009In 2004, Manning showed that the topological entropy of the geodesic flow for a surface of negative curvature decreases as the metric evolves under the normalised Ricci flow. It is an interesting open problem, also due to Manning, to determine to what ... More
Equilibrium states for products of flows and the mixing properties of rank 1 geodesic flowsJun 21 2019Equilibrium states for geodesic flows over closed rank 1 manifolds were studied recently by Burns, Climenhaga, Fisher and Thompson. For sufficiently regular potentials, it was shown that if the singular set does not carry full pressure then the equilibrium ... More
Measures of maximal entropy for suspension flows over the full shiftAug 01 2017Mar 12 2019We consider suspension flows with continuous roof function over the full shift $\Sigma$ on a finite alphabet. For any positive entropy subshift of finite type $Y \subset \Sigma$, we explictly construct a roof function such that the measure(s) of maximal ... More
Equilibrium states for products of flows and the mixing properties of rank 1 geodesic flowsJun 21 2019Jun 27 2019Equilibrium states for geodesic flows over closed rank 1 manifolds were studied recently by Burns, Climenhaga, Fisher and Thompson. For sufficiently regular potentials, it was shown that if the singular set does not carry full pressure then the equilibrium ... More
Unique equilibrium states for flows and homeomorphisms with non-uniform structureMay 14 2015May 25 2016Using an approach due to Bowen, Franco showed that continuous expansive flows with specification have unique equilibrium states for potentials with the Bowen property. We show that this conclusion remains true using weaker non-uniform versions of specification, ... More
Coding Sequence Density Estimation Via Topological PressureSep 27 2011Jan 08 2014We give a new approach to coding sequence (CDS) density estimation in genomic analysis based on the topological pressure, which we develop from a well known concept in ergodic theory. Topological pressure measures the "weighted information content" of ... More
Intrinsic ergodicity beyond specification: beta-shifts, S-gap shifts, and their factorsNov 11 2010Jun 17 2011We give sufficient conditions for a shift space $(\Sigma,\sigma)$ to be intrinsically ergodic, along with sufficient conditions for every subshift factor of $\Sigma$ to be intrinsically ergodic. As an application, we show that every subshift factor of ... More
Equilibrium states for Mañé diffeomorphismsMar 16 2017Oct 24 2017We study thermodynamic formalism for the family of robustly transitive diffeomorphisms introduced by Ma\~n\'e, establishing existence and uniqueness of equilibrium states for natural classes of potential functions. In particular, we characterize the SRB ... More
Revisiting the (110) Surface Structure of TiO2: A Detailed Theoretical AnalysisNov 14 2005Jan 30 2006A detailed reexamination of the (110) surface structure of rutile TiO2 has been carried out using first-principles total-energy methods. This investigation is in response to a recent high-precision LEED-IV measurement revealing certain significant quantitative ... More
Unique equilibrium states for Bonatti-Viana diffeomorphismsMay 23 2015Feb 21 2018We show that the robustly transitive diffeomorphisms constructed by Bonatti and Viana have unique equilibrium states for natural classes of potentials. In particular, we characterize the SRB measure as the unique equilibrium state for a suitable geometric ... More
Nonlinear softening as a predictive precursor to climate tippingMar 15 2011Dec 09 2011Approaching a dangerous bifurcation, from which a dynamical system such as the Earth's climate will jump (tip) to a different state, the current stable state lies within a shrinking basin of attraction. Persistence of the state becomes increasingly precarious ... More
Climate tipping as a noisy bifurcation: a predictive techniqueJul 08 2010Nov 30 2010It is often known, from modelling studies, that a certain mode of climate tipping (of the oceanic thermohaline circulation, for example) is governed by an underlying fold bifurcation. For such a case we present a scheme of analysis that determines the ... More
Collapse and expansion in the bright-rimmed cloud SFO 11NEFeb 24 2004We report the results of a search for the double-peaked blue-skewed infall signature in the bright-rimmed cloud core SFO 11NE SMM1. Observations of the optically thick HCO$^{+}$ and optically thin H$^{13}$CO$^{+}$ J=3--2 lines reveal that there is indeed ... More
Clusters AgeS Experiment. Hot subdwarfs and luminous white dwarf candidates in the field of the globular cluster M4Aug 28 2000May 28 2002We present UBV color magnitude diagrams (CMDs) for the globular cluster M4. The CMDs show a sequence of four luminous blue stars (V<20, U-V<-0.6) which appear to be cluster hot subdwarfs. We present spectra for the three brightest ones. We also note the ... More
Local Susceptibility of the Yb2Ti2O7 Rare Earth Pyrochlore Computed from a Hamiltonian with Anisotropic ExchangeFeb 02 2011The rare earth pyrochlore magnet Yb2Ti2O7 is among a handful of materials that apparently exhibit no long range order down to the lowest explored temperatures and well below the Curie-Weiss temperature. Paramagnetic neutron scattering on a single crystal ... More
A Compact Array imaging survey of southern bright-rimmed cloudsNov 03 2003We have carried out a radio-wavelength imaging survey of 45 bright-rimmed clouds (BRCs), using the Australia Telescope Compact Array to characterise the physical properties in their ionised boundary layers. We detected radio emission from a total of 25 ... More
A photometric survey for variable stars in the globular cluster M5Oct 12 1999We present the results of a photometric survey for variable stars in the nearby globular cluster M5. A 14.8x22.8 arcmin^2 field centered on the cluster was monitored for a total of 37 hours with a CCD camera mounted on the 1.0-m Swope telescope. Five ... More
The weak specification property for geodesic flows on CAT(-1) spacesJun 20 2016May 17 2019We prove that the geodesic flow on a compact locally CAT(-1) space has the weak specification property, and give various applications. We show that every H\"older potential on the space of geodesics has a unique equilibrium state. We establish the equidistribution ... More
Thermodynamical Signatures of an Excitonic InsulatorFeb 22 2008Feb 24 2008In the 1960s speculations arose if a ground state exists in solid state materials with an electron and a hole bound to a pair with their spins added to integer values, i.e. excitons. Here we show that electrons and holes in TmSe0.45Te0.55 do form excitons ... More
Geometrical Distance Determination using Type I X-ray BurstsJun 26 2006With the excellent angular resolution of the Chandra X-ray Observatory, it is possible to geometrically determine the distance to variable Galactic sources, based on the phenomenon that scattered radiation appearing in the X-ray halo has to travel along ... More
The Clusters AgeS Experiment (CASE). Variable stars in the field of the open cluster NGC 6253May 22 2014The field of the metal-rich open cluster NGC 6253 has been surveyed in a search for variable stars. A total of 25 new variables were detected, 14 of which are bright stars with 13<V<15 mag. This domain was not covered in an earlier work by de Marchi et ... More
Investigation of the triple-alpha reaction in a full three-body approachSep 22 2012May 15 2013Background: The triple-alpha reaction is the key to our understanding about the nucleosynthesis and the observed abundance of $^{12}$C in stars. The theory of this process is well established at high temperatures but rather ambiguous in the low temperature ... More
Nonlinear Dynamics of Spherical Shells Buckling under Step PressureDec 16 2018Feb 06 2019Dynamic buckling is addressed for complete elastic spherical shells subject to a rapidly applied step in external pressure. Insights from the perspective of nonlinear dynamics reveal essential mathematical features of the buckling phenomena. To capture ... More
Unique equilibrium states for geodesic flows in nonpositive curvatureMar 31 2017Aug 28 2018We study geodesic flows over compact rank 1 manifolds and prove that sufficiently regular potential functions have unique equilibrium states if the singular set does not carry full pressure. In dimension 2, this proves uniqueness for scalar multiples ... More
Rippling of GrapheneJul 18 2008Meyer et al (2007) found that free-standing graphene sheets, just one atom thick, display spontaneous ripples. The ripples are of order 2-20 {\AA} high and 20-200 {\AA} wide. The sheets in which they appear are only one atom thick, and extend for around ... More
Strong symbolic dynamics for geodesic flow on CAT(-1) spaces and other metric Anosov flowsAug 13 2018Apr 04 2019We prove that the geodesic flow on a compact, locally CAT(-1) metric space can be coded by a suspension flow over an irreducible shift of finite type with H\"older roof function. This is achieved by showing that the geodesic flow is a metric Anosov flow, ... More
Multiwavelength Opportunities and Challenges in the Era of Public Fermi DataDec 29 2009The gamma-ray survey of the sky by the Fermi Gamma-ray Space Telescope offers both opportunities and challenges for multiwavelength and multi-messenger studies. Gamma-ray bursts, pulsars, binary sources, flaring Active Galactic Nuclei, and Galactic transient ... More
Embedded Star Formation in the Eagle NebulaJan 17 2002M16=NGC 6611, the Eagle Nebula, is a well studied region of star formation and the source of a widely recognized Hubble Space Telescope (HST) image. High spatial resolution infrared observations with the Near Infrared Camera and Multi-Object Spectrometer ... More
Effects of core degrees of freedom in the low energy $^7$Be$(p,γ)^8$B reactionSep 29 1997Quadrupole and octupole couplings to all bound states of $^7$Be are included in describing the capture reaction $^7$Be$(p,\gamma)^8$B. We verify, contrary to what we had initially stated, that the energy behaviour of the Astrophysical S-factor in the ... More
(^{8})B breakup in elastic and transfer reactionsApr 01 2002We have studied the transfer reaction $^{14}$N($^7$Be,$^8$B)$^{13}$C at (\mathrm{E}_{\mathrm{lab}}=84) MeV, paying special attention to the effects of the coupling to the continuum in the exit channel. Using the Continuum Discretized Coupled Channels ... More
Use of time-correlated single photon counting detection to measure the speed of light in waterFeb 18 2005Traditional methods for measuring the speed of light in dispersive media have been based on the detection of interference between light waves emitted from the same source. In the present study the elapsed times for single photons to move from a laser ... More
Effect of Carbon-Doping in Bulk Superconducting MgB2 SamplesApr 05 2001Bulk superconducting samples of MgB2 were prepared by solid state reaction of stoichiometric quantities of Mg turnings and B in a sealed Ta cylinder at 890 C for 2 hours. The as-synthesized MgB2 samples had a Tc of 39 K, as defined as the onset of diamagnetism. ... More
Using quantum theory to reduce the complexity of input-output processesJan 20 2016Feb 13 2017All natural things process and transform information. They receive environmental information as input, and transform it into appropriate output responses. Much of science is dedicated to building models of such systems -- algorithmic abstractions of their ... More
Multiple stellar generations in massive star forming complexesDec 15 2010The formation of massive stars is an outstanding problem in stellar evolution. However, it is expected that they are (predominantly) born in heirarchical environments within massive young clusters, which in turn are located within larger star forming ... More
Alleviating polarity-conflict at the heterointerfaces of KTaO$_3$/GdScO$_3$ polar complex-oxidesJan 31 2014Sep 09 2014We have synthesized and investigated the heterointerfaces of KTaO$_3$ (KTO) and GdScO$_3$ (GSO), which are both polar complex-oxides along the pseudo-cubic [001] direction. Since their layers have the same, conflicting net charges at interfaces, i.e. ... More
STEREO/EUVI Event Catalog 2006-2012Jun 13 2013We generated an event catalog with an automated detection algorithm based on the entire EUVI image database observed with the two Solar Terrestrial Relations Observatory STEREO-A and -B spacecraft over the first six years of the mission (2006\,--\,2012). ... More
Electronic Duality in Strongly Correlated MatterMay 16 2008Superconductivity develops from an attractive interaction between itinerant electrons that creates electron pairs which condense into a macroscopic quantum state--the superconducting state. On the other hand, magnetic order in a metal arises from electrons ... More
Magnetic Structure of Heavy Fermion Ce2RhIn8Feb 13 2001Mar 02 2001Magnetic structure of the heavy fermion antiferromagnet Ce2RhIn8 is determined using neutron diffraction.
Suppression of Antiferromagnetic Order by Light Hole Doping in La_2Cu_{1-x}Li_xO_4: A ^{139}La NQR StudyApr 18 1998Jul 13 1998^{139}La nuclear quadrupole resonance measurements in lightly doped La_2Cu_{1-x}Li_xO_4 have been performed to reveal the dependence of the magnetic properties of the antiferromagnetic CuO_2 planes on the character of the doped holes and their interactions ... More
A Radio and Mid-Infrared Survey of Northern Bright-Rimmed CloudsJul 08 2004We have carried out an archival radio, optical and infrared wavelength imaging survey of 44 Bright-Rimmed Clouds (BRCs) using the NRAO/VLA Sky Survey (NVSS) archive, images from the Digitised Sky Survey (DSS) and the Midcourse Space eXperiment (MSX). ... More
A SCUBA survey of bright-rimmed cloudsNov 05 2007Context: Bright-rimmed clouds (BRCs) are potential examples of triggered star formation regions, in which photoionisation driven shocks caused by the expansion of HII regions induce protostellar collapse within the clouds. Aims: The main purpose of the ... More
High-mass star formation within the bright-rimmed cloud SFO 79Aug 11 2004We report Radio Recombination Line (RRL) and continuum observations toward the IRAS point source 16362--4845, embedded within the Bright-Rimmed Cloud (BRC) SFO 79, a small molecular cloud lying at the edge of the HII region RCW 108. High resolution observations ... More
$1/T_1$ in the D-wave superconducting state with coexisting antiferromagnetismJun 18 2003We consider a general D-wave superconducting gap function in the presence of coexisting antiferromagnetic (AFM) long-rang order. We find that the D-wave order parameter develops additional nodes without lowering the symmetry of the state due to the interplay ... More
Physical properties of the noncentrosymmetric superconductor Mg_10Ir_19B_16Jun 14 2007Jan 07 2008Specific heat, electrical resistivity, and magnetic susceptibility measurements on a high quality sample of Mg10Ir19B16 provide a self-consistent determination of its superconducting properties. They indicate that Mg10Ir19B16 is a type-II superconductor ... More
Lifting the Iron Curtain : Toward an Understanding of the Iron Stars XX Oph and AS 325Feb 17 2005We present new optical, near infrared, and archival ultraviolet observations of XX Ophiuchi and AS 325, two proposed iron stars. These unusual stars have optical spectra dominated by emission lines arising from hydrogen as well as ionized metals such ... More
Carbonate Formation in Non-Aqueous Environments by Solid-Gas Carbonation of SilicatesDec 10 2012We have produced synthetic analogues of cosmic silicates using the Sol Gel method, producing amorphous silicates of composition Mg(x)Ca(1-x)SiO3. Using synchrotron X-ray powder diffraction on Beamline I11 at the Diamond Light Source, together with a newly-commissioned ... More
The G305 star forming complex: Wide-Area molecular mapping of NH3 and H2O masersJun 10 2010We present wide area radio (12 mm) Mopra Telescope observations of the complex and rich massive star forming region G305. Our goals are to determine the reservoir for star formation within G305 using NH3 to trace the dense molecular content, and thus, ... More
Magnetotransport in the CeIrIn${_5}$ system: The influence of antiferromagnetic fluctuationsOct 10 2008We present an overview of magnetotransport measurements on the heavy-fermion superconductor CeIrIn$_5$. Sensitive measurements of the Hall effect and magnetoresistance (MR) are used to elucidate the low temperature phase diagram of this system. The normal-state ... More
Analysis of the normal state magnetotransport in CeIrIn${_5}$Oct 10 2008We present an analysis of the normal state magnetotransport in the heavy fermion superconductor CeIrIn${_5}$. The Hall effect and the transverse magnetoresistance in this material do not appear to be uniquely correlated, as inferred from the field dependence ... More
Extended Nuclear Quadrupole Resonance Study of the Heavy-Fermion Superconductor PuCoGa$_5$Nov 06 2016PuCoGa$_5$ has emerged as a prototypical heavy-fermion superconductor, with its transition temperature ($T_c\simeq18.5$ K) being the highest amongst such materials. Nonetheless, a clear description as to what drives the superconducting pairing is still ... More
Pressure Study of Quantum Criticality in CeCoIn5Feb 03 2006We report resistivity measurements in the normal state of CeCoIn5 down to 40 mK and simultaneously in magnetic fields up to 9 T in the [001] crystallographic direction and under pressures up to 1.3 GPa. At ambient pressure the data are consistent with ... More
Optical spectroscopy and ultrafast pump-probe studies on the heavy fermion compound CePt$_2$In$_7$Mar 21 2016We report optical spectroscopy and ultrafast pump-probe measurements on the antiferromagnetic heavy fermion compound CePt$_2$In$_7$, a member showing stronger two dimensionality than other compounds in CeIn$_3$-derived heavy-fermion family. We identify ... More
Triggered star formation in Bright-Rimmed Clouds: The Eagle Nebula revisitedMar 09 2006A three dimensional Smoothed Particle Hydrodynamical (SPH) model has been extended to study the radiative driven implosion effect of massive stars on the dynamical evolutions of surrounding molecular clouds. The new elements in the upgraded code are the ... More
An Investigation on the Morphological Evolution of Bright-Rimmed CloudsOct 15 2008A new Radiative Driven Implosion (RDI) model based on Smoothed Particle Hydrodynamics (SPH) technique is developed and applied to investigate the morphological evolutions of molecular clouds under the effect of ionising radiation. This model self-consistently ... More
Detecting Cross-Lingual Plagiarism Using Simulated Word EmbeddingsDec 29 2017Jan 03 2018Cross-lingual plagiarism (CLP) occurs when texts written in one language are translated into a different language and used without acknowledging the original sources. One of the most common methods for detecting CLP requires online machine translators ... More
Finding geodesics in a triangulated 2-sphereAug 25 2014Sep 09 2014Let S be a triangulated 2-sphere with fixed triangulation T. We apply the methods of thin position from knot theory to obtain a simple version of the three geodesics theorem for the 2-sphere [5]. In general these three geodesics may be unstable, corresponding, ... More
Some Graftings of Complex Projective Structures with Schottky HolonomyDec 10 2010Jan 27 2013Let $\mathcal{G}^*(S,\rho)$ be the graph whose vertices are marked complex projective structures with holonomy $\rho$ and whose edges are graftings from one vertex to another. If $\rho$ is quasi-Fuchsian, a theorem of Goldman implies that $\mathcal{G}^*(S,\rho)$ ... More
Point-Contact Spectroscopy of the Heavy-Fermion Superconductor CeCoIn$_5$Sep 03 2004Nov 16 2004The dynamic conductance of the heavy-fermion superconductor CeCoIn$_5$ is measured by point-contact spectroscopy as a function of temperature from 60 K down to 400 mK. The contact between the gold tip and the single-crystal is shown to be in the Sharvin ... More
Self-organized current transport through low angle grain boundaries in YBa$_2$Cu$_3$O$_{7-δ}$ thin films, studied magnetometricallyAug 16 2003The critical current density flowing across low angle grain boundaries in YBa$_2$Cu$_3$O$_{7-\delta}$ thin films has been studied magnetometrically. Films (200 nm thickness) were deposited on SrTiO$_3$ bicrystal substrates containing a single [001] tilt ... More
Anomalous Pressure Dependence of Kadowaki-Woods ratio and Crystal Field Effects in Mixed-valence YbInCu4Sep 09 2004Mar 04 2006The mixed-valence (MV) compound YbInCu4 was investigated by electrical resistivity and ac specific heat at low temperatures and high pressures. At atmospheric pressure, its Kadowaki-Woods (KW) ratio, A/\gamma ^2, is 16 times smaller than the universal ... More
The G305 star-forming complex: a wide-area radio survey of ultra-compact HII regionsJan 16 2012We present wide-area radio continuum 5.5 and 8.8 GHz (5.5 and 3.4 cm) Australia Telescope Compact Array observations of the complex and rich massive star-forming region G305. The aim of this study is to perform an un-targeted survey of the region in search ... More
Superconductivity in CeCoIn5-xSnx: Veil Over an Ordered State or Novel Quantum Critical Point?Sep 21 2004Measurements of specific heat and electrical resistivity in magnetic fields up to 9 T along [001] and temperatures down to 50 mK of Sn-substituted CeCoIn5 are reported. The maximal -ln(T) divergence of the specific heat at the upper critical field H_{c2} ... More
A generalization of the Goresky-Klapper conjecture, Part IMay 05 2018For a fixed integer $n\geq 2,$ we show that a permutation of the least residues mod $p$ of the form $f(x)=Ax^k$ mod $p$ cannot map a residue class mod $n$ to just one residue class mod $n$ once $p$ is sufficiently large, other than the maps $f(x)=\pm ... More
Radio continuum and molecular line observations of four bright-rimmed cloudsJan 31 2006We present the results of radio continuum and molecular line observations conducted using the Mopra millimetre-wave telescope and Australia Telescope Compact Array. These observations reveal the presence of a dense core embedded within each cloud, and ... More
The Sum of Four Squares Over Real Quadratic Number FieldsOct 21 2016May 23 2018Well-known results of Lagrange and Jacobi prove that the every $m \in \mathbb N$ can be expressed as a sum of four integer squares, and the number $r(m)$ of such representations can be given by an explicit formula in $m$. In this paper, we prove that ... More
Magnetic vortex dynamics in a 2D easy plane ferromagnetOct 16 2005In this thesis, we consider the dynamics of vortices in the easy plane insulating ferromagnet in two dimensions. In addition to the quasiparticle excitations, here spin waves or magnons, this magnetic system admits a family of vortex solutions carrying ... More
Invariants of curves in RP^2 and R^2Feb 01 2006Jun 30 2009There is an elegant relation found by Fabricius-Bjerre [Math. Scand 40 (1977) 20--24] among the double tangent lines, crossings, inflections points, and cusps of a singular curve in the plane. We give a new generalization to singular curves in RP^2. We ... More
A Thermodynamic Definition of Topological Pressure for Non-Compact SetsJul 14 2008Feb 11 2010We give a new definition of topological pressure for arbitrary (non-compact, non-invariant) Borel subsets of metric spaces. This new quantity is defined via a suitable variational principle, leading to an alternative definition of an equilibrium state. ... More
The rate of escape of random walks on polycyclic and metabelian groupsOct 05 2010Sep 13 2011We use subgroup distortion to determine the rate of escape of a simple random walk on a class of polycyclic groups, and we show that the rate of escape is invariant under changes of generating set for these groups. For metabelian groups, we define a stronger ... More
An Unstable Change of Rings for Morava E-TheorySep 12 2014Mar 16 2018The Bousfield-Kan (or unstable Adams) spectral sequence can be constructed for various homology theories such as Brown-Peterson homology theory BP, Johnson-Wilson theory $E(n)$, or Morava $E$-theory $E_n$. For nice spaces the $E_2$-term is given by Ext ... More
Functional inequalities for Feynman-Kac semigroupsNov 08 2018Apr 15 2019Using the tools of stochastic analysis, we prove various gradient estimates and Harnack inequalities for Feynman-Kac semigroups with possibly unbounded potentials. One of the main results is a derivative formula which can be used to characterize a lower ... More
Dehn surgery on complicated fibered knots in the 3-sphereApr 17 2016Let K be a fibered knot in the 3-sphere. We show that if the monodromy of K is sufficiently complicated, then Dehn surgery on K cannot yield a lens space. Work of Yi Ni shows that if K has a lens space surgery then it is fibered. Combining this with our ... More
Tori and Heegaard splittingsMar 27 2016Haken showed that the Heegaard splittings of reducible 3-manifolds are reducible, that is, a reducing 2-sphere can be found which intersects the Heegaard surface in a single simple closed curve. When the genus of the "interesting" surface increases from ... More
Four-body continuum-discretized coupled-channels calculationsAug 06 2009Oct 20 2009The development of a continuum-bins scheme of discretization for three-body projectiles is necessary for studies of reactions of Borromean nuclei such as 6He within the continuum-discretized coupled-channels approach. Such a procedure, for constructing ... More
Clusters AgeS Experiment. RR Lyr Variables in the Globular Cluster NGC 6362May 31 2000We present V and B-band CCD photometry of 35 RR Lyr stars in the southern hemisphere globular cluster NGC 6362. Fourier decomposition of the light curves was used to estimate the basic properties of these variables. From the analysis of the RRc stars ... More
Cluster AgeS Experiment (CASE): Deficiency of observed dwarf novae in globular clustersApr 07 2008We present the results of a search for dwarf novae (DNe) in globular clusters (GCs). It is based on the largest available homogeneous sample of observations, in terms of the time span, number of observations and number of clusters. It includes 16 Galactic ... More
Gamma Radiation from PSR B1055-52Nov 13 1998The telescopes on the Compton Gamma Ray Observatory (CGRO) have observed PSR B1055-52 a number of times between 1991 and 1998. From these data, a more detailed picture of the gamma radiation from this source has been developed, showing several characteristics ... More
The Multiwavelength Approach to Unidentified Gamma-Ray SourcesJul 20 2004As the highest-energy photons, gamma rays have an inherent interest to astrophysicists and particle physicists studying high-energy, nonthermal processes. Gamma-ray telescopes complement those at other wavelengths, especially radio, optical, and X-ray, ... More
Irregular sets, the $β$-transformation and the almost specification propertyMay 06 2009May 02 2012Let $(X,d)$ be a compact metric space, $f:X \mapsto X$ be a continuous map satisfying a property we call almost specification (which is slightly weaker than the $g$-almost product property of Pfister and Sullivan), and $\phi$ be a continuous function ... More
Temperature measurement and stabilization in a birefringent whispering gallery resonatorMay 31 2011Temperature measurement with nano-Kelvin resolution is demonstrated at room temperature, based on the thermal dependence of an optical crystal anisotropy in a high quality whispering gallery resonator. As the resonator's TE and TM modes frequencies have ... More
Interplay of the spin density wave and a possible Fulde-Ferrell-Larkin-Ovchinnikov state in $\mathrm{CeCoIn_5}$ in rotating magnetic fieldFeb 13 2019The $d$-wave superconductor $\mathrm{CeCoIn_5}$ has been proposed as a strong candidate for supporting the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state near the low-temperature boundary of its upper critical field. Neutron diffraction, however, finds ... More
Elastic anomalies associated with domain switching in BaTiO$_3$ single crystals under in-situ electrical cyclingJun 09 2019The elastic response of BaTiO$_3$ single crystals during electric field cycling at room temperature has been studied using in-situ Resonant Ultrasound Spectroscopy (RUS), which allows monitoring of both the elastic and anelastic changes caused by ferroelectric ... More
Cluster AgeS Experiment (CASE): Dwarf Novae and a Probable Microlensing Event in the Globular Cluster M22Sep 27 2005We report the identification of a new cataclysmic variable (denoted as CV2) and a probable microlensing event in the field of the globular cluster M22. Two outbursts were observed for CV2. During one of them superhumps with P_sh=0.08875 d were present ... More
Photometry and Spectroscopy of Eclipsing Binaries in omega CentauriNov 05 2001Detached eclipsing double line spectroscopic binaries are accurate distance indicators. They can be used for the direct determination of distances to globular clusters in which such systems can be identified. The results of major photometric surveys aimed ... More
Space Detectors for Gamma Rays (100 MeV - 100 GeV): from EGRET to Fermi LATJun 25 2015The design of spaceborne high-energy (E>100 MeV) gamma-ray detectors depends on two principal factors: (1) the basic physics of detecting and measuring the properties of the gamma rays; and (2) the constraints of operating such a detector in space for ... More
Gamma-Ray Pulsar Studies with GLASTNov 27 2007Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an extended hiatus ... More
Gamma Ray Pulsars: Multiwavelength ObservationsDec 10 2003High-energy gamma rays are a valuable tool for studying particle acceleration and radiation in the magnetospheres of energetic pulsars. The seven or more pulsars seen by instruments on the Compton Gamma Ray Observatory (CGRO) show that: the light curves ... More
The Changing Face of $α$ Centauri B: Probing plage and stellar activity in K-dwarfsFeb 06 2017A detailed knowledge of stellar activity is crucial for understanding stellar dynamos, as well as pushing exoplanet radial-velocity detection limits towards Earth analogue confirmation. We directly compare archival HARPS spectra taken at the minimum in ... More
Zero-range processes with saturated condensation: the steady state and dynamicsDec 15 2009Feb 16 2010We study a class of zero-range processes in which the real-space condensation phenomenon does not occur and is replaced by a saturated condensation: that is, an extensive number of finite-size "condensates" in the steady state. We determine the conditions ... More
The 2017 ISO New England System Operational Analysis and Renewable Energy Integration Study (SOARES)Dec 12 2018Dec 13 2018The bulk electric power system in New England is fundamentally changing. The representation of nuclear, coal and oil generation facilities is set to dramatically fall, and natural gas, wind and solar facilities will come to fill their place. The introduction ... More
A multiscale mathematical model of tumour invasive growthMar 24 2016Known as one of the hallmarks of cancer [30], cancer cell invasion of human body tissue is a complicated spatio-temporal multiscale process which enables a localised solid tumour to transform into a systemic, metastatic and fatal disease. This process ... More
Low-temperature triple-alpha rate in a full three-body modelDec 09 2011Aug 02 2012A new full three-body method is introduced to compute the rate of the triple-alpha capture reaction which is the primary source of $^{12}$C in stars. In this work, we combine the Faddeev hyperspherical harmonics and the R-matrix method to obtain a full ... More
Pressure-induced superconductivity in single crystal CaFe2As2Jul 04 2008We report pressure-induced superconductivity in a single crystal of CaFe2As2. At atmospheric pressure, this material is antiferromagnetic below 170 K but under an applied pressure of 0.69 GPa becomes superconducting, with a transition temperature Tc exceeding ... More
Influence of nonlocal electrodynamics on the anisotropic vortex pinning in $YNi_2B_2C$Jun 06 2000Jun 25 2001We have studied the pinning force density Fp of YNi_2B_2C superconductors for various field orientations. We observe anisotropies both between the c-axis and the basal plane and within the plane, that cannot be explained by usual mass anisotropy. For ... More
Grand Challenges in the Physics of the Sun and Sun-like StarsJun 17 2014The study of stellar structure and evolution is one of the main building blocks of astrophysics, and the Sun has an importance both as the star that is most amenable to detailed study and as the star that has by far the biggest impact on the Earth and ... More
Gamma Ray Pulsars: ObservationsJan 03 2001High-energy gamma rays are a valuable tool for studying particle acceleration and radiation in the magnetospheres of energetic pulsars. The six or more pulsars seen by CGRO/EGRET show that: the light curves usually have double-peak structures (suggesting ... More
The Gamma-ray Sky with FermiAug 08 2013Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, solar flares, and flaring ... More
Advances in Shell Buckling: Theory and ExperimentsSep 10 2014In a recent feature article in this journal, co-authored by Gert van der Heijden, I described the static-dynamic analogy and its role in understanding the localized post-buckling of shell-like structures, looking exclusively at integrable systems. We ... More
Measurements of alpha_s from hadronic event shapes in e+e- annihilationDec 02 1998New studies of hadronic event shape observables in e+ e- collisions between 13 and 183 GeV CM energy have enabled the running of alpha_s to be confirmed and the validity of non-perturbative power-law corrections to be investigated. A more precise value ... More
Towards a Molecular Inventory of Protostellar DiscsNov 27 2003The chemical environment in circumstellar discs is a unique diagnostic of the thermal, physical and chemical environment. In this paper we examine the structure of star formation regions giving rise to low mass stars, and the chemical environment inside ... More