Results for "A. J. Sigillito"

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Anisotropic Stark Effect and Electric-Field Noise Suppression for Phosphorus Donor Qubits in SiliconSep 11 2014Mar 08 2015We report the use of novel, capacitively terminated coplanar waveguide (CPW) resonators to measure the quadratic Stark shift of phosphorus donor qubits in Si. We confirm that valley repopulation leads to an anisotropic spin-orbit Stark shift depending ... More
Addressing spin transitions on 209Bi donors in silicon using circularly-polarized microwavesJan 21 2016Jan 22 2016Over the past decade donor spin qubits in isotopically enriched $^{28}$Si have been intensely studied due to their exceptionally long coherence times. More recently bismuth donor electron spins have become popular because Bi has a large nuclear spin which ... More
Electron Spin Resonance at the Level of 10000 Spins Using Low Impedance Superconducting ResonatorsAug 17 2016We report on electron spin resonance (ESR) measurements of phosphorus donors localized in a 200 square micron area below the inductive wire of a lumped element superconducting resonator. By combining quantum limited parametric amplification with a low ... More
Quantum CNOT Gate for Spins in SiliconAug 11 2017Single qubit rotations and two-qubit CNOT operations are crucial ingredients for universal quantum computing. While high fidelity single qubit operations have been achieved using the electron spin degree of freedom, realizing a robust CNOT gate has been ... More
Large Stark tuning of donor electron spin quantum bits in germaniumJun 10 2016Jun 30 2016Donor electron spins in semiconductors make exceptional quantum bits because of their long coherence times and compatibility with industrial fabrication techniques. Despite many advances in donor-based qubit technology, it remains difficult to selectively ... More
High-fidelity quantum gates in Si/SiGe double quantum dotsNov 02 2017Motivated by recent experiments of Zajac et al. [arXiv:1708.03530], we theoretically describe high-fidelity two-qubit gates using the exchange interaction between the spins in neighboring quantum dots subject to a magnetic field gradient. We use a combination ... More
Fast high-fidelity entangling gates in Si double quantum dotsFeb 06 2019Implementing high-fidelity two-qubit gates in single-electron spin qubits in silicon double quantum dots is still a major challenge. In this work, we employ analytical methods to design control pulses that generate high-fidelity entangling gates for quantum ... More
Site-selective quantum control in an isotopically enriched 28Si/SiGe quadruple quantum dotMar 14 2019Silicon spin qubits are a promising quantum computing platform offering long coherence times, small device sizes, and compatibility with industry-backed device fabrication techniques. In recent years, high fidelity single-qubit and two-qubit operations ... More
Electron spin coherence of shallow donors in natural and isotopically enriched germaniumJun 18 2015Nov 07 2015Germanium is a widely used material for electronic and optoelectronic devices and recently it has become an important material for spintronics and quantum computing applications. Donor spins in silicon have been shown to support very long coherence times ... More
Fast, low-power manipulation of spin ensembles in superconducting microresonatorsFeb 28 2014May 02 2014We demonstrate the use of high-Q superconducting coplanar waveguide (CPW) microresonators to perform rapid manipulations on a randomly distributed spin ensemble using very low microwave power (400 nW). This power is compatible with dilution refrigerators, ... More
Theory of incompressible MHD turbulence with scale-dependent alignment and cross-helicityMar 29 2009Feb 06 2010(Abridged) An anisotropic theory of MHD turbulence with nonvanishing cross-helicity is constructed based on Boldyrev's alignment hypothesis and probabilities p and q for fluctuations v and b to be positively or negatively aligned. Guided by observations ... More
Effects of dynamical evolution on the distribution of substructuresDec 15 2004We develop a semi-analytical model that determines the evolution of the mass, position and internal structure of dark matter substructures orbiting in dark matter haloes. We apply this model to the case of the Milky Way. We focus in particular on the ... More
Particle acceleration in ultra-relativistic parallel shock wavesDec 13 2002Monte-Carlo computations for highly relativistic parallel shock particle acceleration are presented for upstream flow gamma factors, $\Gamma=(1-V_{1}^{2}/c^{2})^{-0.5}$ with values between 5 and $10^{3}$. The results show that the spectral shape at the ... More
Pair Multiplicities and Pulsar DeathFeb 09 2001Through a simple model of particle acceleration and pair creation above the polar caps of rotation-powered pulsars, we calculate the height of the pair-formation front (PFF) and the dominant photon emission mechanism for the pulsars in the Princeton catalog. ... More
Quantum Weyl algebrasOct 30 1993For any Hecke symmetry $R$ there is a natural quantization $A_n(R)$ of the Weyl algebra $A_n$. The aim of this paper is to study some general ring-theoretic aspects of $A_n(R)$ and its relations to formal deformations of $A_n$. We also obtain further ... More
Seifert fibred knot manifoldsJan 09 2013Aug 05 2013We consider the question of when is the closed manifold obtained by elementary surgery on an $n$-knot Seifert fibred over a 2-orbifold. After some observations on the classical case, we concentrate on the cases n=2 and 3. We have found a new family of ... More
Power correlations in cosmology: limits on primordial non-Gaussian density fieldsAug 15 1996We probe the statistical nature of the primordial density field by measuring correlations between the power in adjacent Fourier modes. For certain types of non-Gaussian field, these k-space correlations would be expected to be more extended than for a ... More
Dynamics of Barred GalaxiesAug 30 2006Some 30% of disc galaxies have a pronounced central bar feature in the disc plane and many more have weaker features of a similar kind. Kinematic data indicate that the bar constitutes a major non-axisymmetric component of the mass distribution and that ... More
Electron-Phonon Interactions in Correlated Systems: Adiabatic Expansion of the Dynamical Mean-Field TheoryApr 12 2000Jan 29 2002We use the dynamical mean field theory to develop a systematic and computationally tractable method for studying electron-phonon interactions in systems with arbitrary electronic correlations. The method is formulated as an adiabatic expansion around ... More
Oscillating neutrinos and mu --> e, gammaMar 06 2001Nov 07 2001If neutrino masses and mixings are suitable to explain the atmospheric and solar neutrino fluxes, this amounts to contributions to FCNC processes, in particular mu --> e, gamma. If the theory is supersymmetric and the origin of the masses is a see-saw ... More
Anisotropic pressure in dense neutron matter under the presence of a strong magnetic fieldDec 22 2011Dense neutron matter with recently developed BSk19 and BSk21 Skyrme effective forces is considered in magnetic fields up to $10^{20}$ G at zero temperature. The breaking of the rotational symmetry by the magnetic field leads to the differentiation between ... More
Finite temperature effects on spin polarization of neutron matter in a strong magnetic fieldMar 03 2010Sep 15 2010Spin polarization of neutron matter at finite temperatures and strong magnetic fields up to $10^{18}$ G is studied in the model with the Skyrme effective interaction. It is shown that, together with the thermodynamically stable branch of solutions for ... More
Chaotic dynamics with MaximaJan 15 2013We present an introduction to the study of chaos in discrete and continuous dynamical systems using the CAS Maxima. These notes are intended to cover the standard topics and techniques: discrete and continuous logistic equation to model growth population, ... More
Radial Mixing in Galactic DiscsMar 28 2002Jul 03 2002We show that spiral waves in galaxy discs churn the stars and gas in a manner that largely preserves the overall angular momentum distribution and leads to little increase in random motion. Changes in the angular momenta of individual stars are typically ... More
Non-Fermi liquid fixed point for an imbalanced gas of fermions in $1+ε$ dimensionsDec 17 2009Dec 26 2009We consider a gas of two species of fermions with population imbalance. Using the renormalization group in $d=1+\epsilon$ dimensions, we show that for spinless fermions and $\epsilon > 0$ a fixed point appears at finite attractive coupling where the quasiparticle ... More
Tests of mode coupling theory in a simple model for two-component miscible polymer blendsAug 06 2007Sep 26 2007We present molecular dynamics simulations on the structural relaxation of a simple bead-spring model for polymer blends. The introduction of a different monomer size induces a large time scale separation for the dynamics of the two components. Simulation ... More
Substrate concentration dependence of the diffusion-controlled steady-state rate constantDec 20 2004The Smoluchowski approach to diffusion-controlled reactions is generalized to interacting substrate particles by including the osmotic pressure and hydrodynamic interactions of the nonideal particles in the Smoluchoswki equation within a local-density ... More
Symplectic torus actions with coisotropic principal orbitsNov 28 2005Jan 10 2006In this paper we completely classify symplectic actions of a torus $T$ on a compact connected symplectic manifold $(M, \sigma)$ when some, hence every, principal orbit is a coisotropic submanifold of $(M, \sigma)$. That is, we construct an explicit model, ... More
Type-II Bose-Mott insulatorsJul 02 2012Sep 25 2012The Mott insulating state formed from bosons is ubiquitous in solid He-4, cold atom systems, Josephson junction networks and perhaps underdoped high-Tc superconductors. We predict that close to the quantum phase transition to the superconducting state ... More
A fractal set from the binary reflected Gray codeOct 14 2005The permutation associated with the decimal expression of the binary reflected Gray code with $N$ bits is considered. Its cycle structure is studied. Considered as a set of points, its self-similarity is pointed out. As a fractal, it is shown to be the ... More
A fast and accurate algorithm for solving Bernstein-Vandermonde linear sytemMay 22 2006Sep 27 2006A fast and accurate algorithm for solving a Bernstein-Vandermonde linear system is presented. The algorithm is derived by using results related to the bidiagonal decomposition of the inverse of a totally positive matrix by means of Neville elimination. ... More
Large-scale structure and matter in the universeSep 08 2003This paper summarizes the physical mechanisms that encode the type and quantity of cosmological matter in the properties of large-scale structure, and reviews the application of such tests to current datasets. The key lengths of the horizon size at matter-radiation ... More
Defect Relaxation and Coarsening ExponentsFeb 17 1998The coarsening exponents describing the growth of long-range order in systems quenched from a disordered to an ordered phase are discussed in terms of the decay rate, omega(k), for the relaxation of a distortion of wavevector k applied to a topological ... More
Strain dependent conductivity in biased bilayer grapheneApr 07 2014Dec 03 2014Intrinsic bilayer graphene is a gapless semimetal. Under the application of a bias field it becomes a semiconductor with a direct band gap that is proportional to the applied field. Under a layer-asymmetric strain (where the upper layer undergoes compression ... More
The classical sphaleron transition rate exists and is equal to $1.1(α_w T)^4$Aug 01 1995Sep 26 1995Results of a large scale numerical simulation show that the high temperature Chern-Simons number diffusion rate in the electroweak theory has a classical limit $\Gamma = \kappa (\alpha_w T)^4$, where $\kappa = 1.09\pm 0.04$ and $\alpha_w$ is the weak ... More
Stochastic Biasing and Galaxy-Mass Density Relation in the Weakly Non-linear RegimeSep 16 1998Apr 01 1999It is believed that the biasing of the galaxies plays an important role for understanding the large-scale structure of the universe. In general, the biasing of galaxy formation could be stochastic. Furthermore, the future galaxy survey might allow us ... More
Electron transport through molecules in the Kondo regime: the role of molecular vibrationsDec 17 2009We discuss the electronic transport through molecules in the Kondo regime. We concentrate here on the influence of molecular vibrations. Two types of vibrations are investigated: (i) the breathing internal molecular modes, where the coupling occurs between ... More
Entanglement and the Kondo effect in double quantum dotsJan 16 2007We investigate entanglement between electrons in serially coupled double quantum dots attached to non interacting leads. In addition to local repulsion we consider the influence of capacitive inter-dot interaction. We show how the competition between ... More
Does SUSY know about the Standard Model?Apr 07 2013The BRST cohomology of free chiral SUSY has a wealth of Extraordinary Invariants. When one adds a superpotential to the free theory, the extention of the Extraordinary Invariants leads to some constraints on that superpotential. A particularly simple ... More
The Zakharov-Shabat spectral problem on the semi-line: Hilbert formulation and applicationsMay 30 2001The inverse spectral transform for the Zakharov-Shabat equation on the semi-line is reconsidered as a Hilbert problem. The boundary data induce an essential singularity at large k to one of the basic solutions. Then solving the inverse problem means solving ... More
Suppression of coherence degradation due to plasma contribution in high-power supercontinuum generation in coated metallic hollow waveguidesMar 03 2009We study the suppression of noise degradation in high-power soliton-induced supercontinuum generation under the influence of plasma contributions in metallic dielectric-coated hollow waveguides. The high coherence of the supercontinuum is related to the ... More
Detecting chiral gravity with the pure pseudospectrum reconstruction of the cosmic microwave background polarized anisotropiesApr 26 2014May 05 2014We consider the possible detection of parity violation at the linear level in gravity using polarized anisotropies of the cosmic microwave background. Since such a parity violation would lead to non-zero TB and EB correlations, this makes those odd-parity ... More
Cosmological footprints of loop quantum gravityFeb 02 2009Mar 04 2009The primordial spectrum of cosmological tensor perturbations is considered as a possible probe of quantum gravity effects. Together with string theory, loop quantum gravity is one of the most promising frameworks to study quantum effects in the early ... More
Quantum Bound States Around Black HolesJan 29 2007Dec 19 2007Quantum mechanics around black holes has shown to be one of the most fascinating fields of theoretical physics. It involves both general relativity and particle physics, opening new eras to establish the principles of unified theories. In this article, ... More
Josephson effect in thin-film superconductor/insulator/superconductor junctions with misaligned in-plane magnetic fieldsJul 30 2007We study a tunnel junction consisting of two thin-film s-wave superconductors separated by a thin, insulating barrier in the presence of misaligned in-plane exchange fields. We find an interesting interplay between the superconducting phase difference ... More
Coherent electromagnetic heavy ion reactions: (1) exact treatment of pair production and ionization; (2) mutual Coulomb dissociationJun 30 1999Some recent theoretical results on coherent electromagnetic processes in ultrarelativistic heavy ion reactions are surveyed.
Probing an extended region of Delta m^2 with rapidly oscillating 7Be solar neutrinosJun 28 2001Oct 05 2001If 7Be solar neutrinos can be observed in real time experiments, then an extended region of Delta m^2 can be probed by a proper analysis of the rapidly changing phase of vacuum oscillations due to the eccentricity of the earth's orbit about the sun. For ... More
TBA equations for excited states in the Sine-Gordon modelApr 30 2003Sep 12 2003We propose TBA integral equations for multiparticle soliton (fermion) states in the Sine-Gordon (massive Thirring) model. This is based on T-system and Y-system equations, which follow from the Bethe Ansatz solution in the light-cone lattice formulation ... More
Virial expansion and TBA in O(N) sigma modelsAug 10 2001We study the free energy of the 1+1 dimensional O(N) nonlinear sigma-models for even N using the TBA equations proposed recently. We give explicit formulae for the constant solution of the TBA equations (Y-system) and calculate the first two virial coefficients. ... More
Quantum groupoids and dynamical categoriesNov 18 2003Feb 23 2004In this paper we realize the dynamical categories introduced in our previous paper as categories of modules over bialgebroids; we study the bialgebroids arising in this way. We define quasitriangular structure on bialgebroids and present examples of quasitriangular ... More
$\U_q(sl(n))$-invariant quantization of symmetric coadjoint orbits via reflection equation algebraAug 16 2001Dec 24 2002We study relations between the two-parameter $\U_q(sl(n))$-invariant deformation quantization on $sl^*(n)$ and the reflection equation algebra. The latter is described by a quantum permutation on $\End(\C^n)$ given explicitly. The reflection equation ... More
Velocity distributions in clusters of galaxiesFeb 08 2006Apr 29 2006We employ a high-resolution dissipationless N-body simulation of a galaxy cluster to investigate the impact of subhalo selection on the resulting velocity distributions. Applying a lower limit on the present bound mass of subhalos leads to high subhalo ... More
Entropy of fermionic models on highly frustrated latticesNov 04 2005Spinless fermions on highly frustrated lattices are characterized by a lowest single-particle band which is completely flat. Concrete realizations are provided by the sawtooth chain and the kagome lattice. For these models a real-space picture is given ... More
Community detection in complex networks using Extremal OptimizationJan 16 2005We propose a novel method to find the community structure in complex networks based on an extremal optimization of the value of modularity. The method outperforms the optimal modularity found by the existing algorithms in the literature. We present the ... More
Low-Luminosity AGNs and UnificationJan 05 2002More than one third of all nearby galaxies show indications of low-luminosity nuclear activity. These low-luminosity AGNs (LLAGNs) are traditionally classified into a variety of categories depending on their forbidden-line ratios and on the presence or ... More
(Anti)symmetric multivariate trigonometric functions and corresponding Fourier transformsMay 29 2007Dec 14 2007Four families of special functions, depending on n variables, are studied. We call them symmetric and antisymmetric multivariate sine and cosine functions. They are given as determinants or antideterminants of matrices, whose matrix elements are sine ... More
(Anti)symmetric multivariate exponential functions and corresponding Fourier transformsMay 24 2007We define and study symmetrized and antisymmetrized multivariate exponential functions. They are defined as determinants and antideterminants of matrices whose entries are exponential functions of one variable. These functions are eigenfunctions of the ... More
Polaron Formation in the Three-Band Peierls-Hubbard Model for Cuprate SuperconductorsJan 12 1994Exact diagonalization calculations show a continuous transition from delocalized to small polaron behavior as a function of intersite electron-lattice coupling. A transition, found previously at Hartree-Fock level [Yonemitsu et al., Phys. Rev. Lett. {\bf ... More
Comment on "NMR Experiment Factors Numbers with Gauss Sums"Apr 16 2007Mehring et al. have recently described an elegant nuclear magnetic resonance (NMR) experiment implementing an algorithm to factor numbers based on the properties of Gauss sums. Similar experiments have also been described by Mahesh et al. In fact these ... More
Charge and Color BreakingJul 25 1997The presence of scalar fields with color and electric charge in supersymmetric theories makes feasible the existence of dangerous charge and color breaking (CCB) minima and unbounded from below directions (UFB) in the effective potential, which would ... More
Renormalizing Partial Differential EquationsNov 14 1994In this review paper, we explain how to apply Renormalization Group ideas to the analysis of the long-time asymptotics of solutions of partial differential equations. We illustrate the method on several examples of nonlinear parabolic equations. We discuss ... More
Constraining fundamental stellar parameters using seismology. Application to Alpha Centauri ABMay 26 2005We apply the Levenberg-Marquardt minimization algorithm to seismic and classical observables of the Alpha Cen binary system in order to derive the fundamental parameters of Alpha Cen A+B and to analyze the dependence of these parameters on the chosen ... More
Resonances in the current-voltage characteristics of a dissipative Josephson junctionAug 10 1995The I-V characteristics of a Josephson junction shunted by an Ohmic resistor shows sharp peaks when levels in neighbouring wells are crossing. We consider the shape and size of these peaks using a double-well model where the wells are given in parabolic ... More
Motion in Periodic PotentialsOct 16 1997We consider motion in a periodic potential in a classical, quantum, and semiclassical context. Various results on the distribution of asymptotic velocities are proven.
Atomic exchange mean field study of intermixing of Au on Ag(110)Dec 05 1995A mean field method to study heteroepitaxial thin film growth is applied to growth, intermixing and surface reconstructions of $Au$ on $Ag(110)$. The results are in accordance with experimentally observed ``burrowing'' at submonolayer coverages and growth ... More
Optimizing quantum process tomography with unitary 2-designsNov 07 2007Jan 24 2008We show that weighted unitary 2-designs define optimal measurements on the system-ancilla output state for ancilla-assisted process tomography of unital quantum channels. Examples include complete sets of mutually unbiased unitary-operator bases. Each ... More
Computer algebra compares the stochastic superslow manifold of an averaged SPDE with that of the original slow-fast SPDEApr 19 2012The computer algebra routines documented here empower you to reproduce and check many of the details described by an article on large deviations for slow-fast stochastic systems [abs:1001.4826]. We consider a 'small' spatial domain with two coupled concentration ... More
Use the information dimension, not the HausdorffDec 07 2005Multi-fractal patterns occur widely in nature. In developing new algorithms to determine multi-fractal spectra of experimental data I am lead to the conclusion that generalised dimensions $D_q$ of order $q\leq0$, including the Hausdorff dimension, are ... More
Resolve the multitude of microscale interactions to model stochastic partial differential equationsJun 27 2005Dec 22 2005Constructing numerical models of noisy partial differential equations is very delicate. Our long term aim is to use modern dynamical systems theory to derive discretisations of dissipative stochastic partial differential equations. As a second step we ... More
A step towards holistic discretisation of stochastic partial differential equationsJul 22 2003The long term aim is to use modern dynamical systems theory to derive discretisations of noisy, dissipative partial differential equations. As a first step we here consider a small domain and apply stochastic centre manifold techniques to derive a model. ... More
Low-Dimensional Modelling of Dynamics via Computer AlgebraApr 22 1996I describe a method, particularly suitable to implementation by computer algebra, for the derivation of low-dimensional models of dynamical systems. The method is systematic and is based upon centre manifold theory. Computer code for the algorithm is ... More
D=11 Supermembrane wrapped on calibrated submanifoldsOct 30 2005We construct the Hamiltonian of the D=11 Supermembrane with topological conditions on configuration space. It may be interpreted as a supermembrane theory where all configurations are wrapped in an irreducible way on a calibrated submanifold of a compact ... More
Yet More on the Universal Quantum Area SpectrumMay 17 2010We briefly comment on the quantum area spectra of black holes, paying particular attention to the size of the spacing between adjacent spectral levels. It has previously been conjectured that this spacing is uniform with a universal value of $8\pi$ in ... More
On the "Universal" Quantum Area SpectrumJun 15 2009Jul 03 2009There has been much debate over the form of the quantum area spectrum for a black hole horizon, with the evenly spaced conception of Bekenstein having featured prominently in the discourse. In this letter, we refine a very recently proposed method for ... More
A Brief Editorial on de Sitter Radiation via TunnelingFeb 26 2008Very recently (by which we mean two days ago), Y. Sekiwa submitted a paper [arXiv:0802.3266] that dismisses some previous calculations of the de Sitter radiative temperature. Significantly, these calculations employed the (so-called) tunneling methodology, ... More
Of Bounces, Branes and BoundsJan 06 2003Jan 19 2003Some recent studies have considered a Randall-Sundrum-like brane world evolving in the background of an anti-de Sitter Reissner-Nordstrom black hole. For this scenario, it has been shown that, when the bulk charge is non-vanishing, a singularity-free ... More
Holography: 2-D or not 2-D?Nov 21 2003Jan 11 2004As was recently pointed out by Cadoni, a certain class of two-dimensional gravitational theories will exhibit (black hole) thermodynamic behavior that is reminiscent of a free field theory. In the current letter, a direct correspondence is established ... More
Nearly Degenerate dS Horizons from a 2-D PerspectiveFeb 10 2003Some recent studies have implied that quantum fluctuations will prevent a near-extremal black hole from ever attaining a state of precise extremality. In this paper, we consider the analogous situation for the scenario of a nearly degenerate Schwarzschild-de ... More
Radiative Albedo from a Linearly Fibered Half SpaceJul 02 2016A growing acceptance of fiber reinforced composite materials imparts some relevance to exploring the effects which a predominantly linear scattering lattice may have upon interior radiant transport. Indeed, a central feature of electromagnetic wave propagation ... More
Density correlators in a self-similar cascadeJun 16 1999Multivariate density moments (correlators) of arbitrary order are obtained for the multiplicative self-similar cascade. This result is based on the calculation by Greiner, Eggers and Lipa (reference [1]) where the correlators of the logarithms of the ... More
Converging Perturbative Solutions of the Schroedinger Equation for a Two-Level System with a Hamiltonian Depending Periodically on TimeMar 24 1999We study the Schroedinger equation of a class of two-level systems under the action of a periodic time-dependent external field in the situation where the energy difference 2epsilon between the free energy levels is sufficiently small with respect to ... More
A curious relation between the flat cosmological model and the elliptic integral of the first kindJun 20 2013The dependence of the luminosity distance on the redshift has a key importance in the cosmology. This dependence can well be given by standard functions for the zero cosmological constant. The purpose of this article is to present such a relation also ... More
Centres and nilpotent normal subgroups of 2-knot groupsOct 20 2016Let $\pi$ be a 2-knot group with centre $\zeta\pi$ and Hirsch-Plotkin radical $\sqrt\pi$. We show that (a) either $\pi$ has two ends, or $\pi$ has one end and $\zeta\pi$ is torsion-free, or $\pi$ has infinitely many ends and $\zeta\pi$ is finite; and ... More
2178 And All ThatJul 01 2013Oct 13 2013For integers g >= 3, k >= 2, call a number N a (g,k)-reverse multiple if the reversal of N in base g is equal to k times N. The numbers 1089 and 2178 are the two smallest (10,k)-reverse multiples, their reversals being 9801 = 9x1089 and 8712 = 4x2178. ... More
Charge and orbital order in frustrated Pb3Mn7O15Jan 13 2012Mar 28 2012The candidate magnetoelectric Pb3Mn7O15 has a structure consisting of 1/3 filled Kagome layers linked by ribbons of edge-sharing octahedra in the stacking direction. Previous reports have indicated a complex hexagonal-orthorhombic structural transition ... More
Towards Density Functional Calculations from Nuclear ForcesMar 02 2004We propose a method for microscopic calculations of nuclear ground-state properties in the framework of density functional theory. We discuss how the density functional is equivalent to the effective action for the density, thereby establishing a constructive ... More
Wedge Diffraction as an Instance of Radiative ShieldingOct 06 2016Oct 31 2016The celebrated Sommerfeld wedge diffraction solution is reexamined from a null interior field perspective. Exact surface currents provided by that solution, when considered as disembodied half-plane laminae radiating into an ambient, uniform space both ... More
The static spherically symmetric body in relativistic elasticityJul 01 2007In this paper is discussed a class of static spherically symmetric solutions of the general relativistic elasticity equations. The main point of discussion is the comparison of two matter models given in terms of their stored energy functionals, i.e., ... More
UniversalityMar 30 2011Apr 02 2011Universality of eigenvalue spacings is one of the basic characteristics of random matrices. We give the precise meaning of universality and discuss the standard universality classes (sine, Airy, Bessel) and their appearance in unitary, orthogonal, and ... More
Chiral Phases of Superfluid 3He in an Anisotropic MediumJul 29 2013I report theoretical analysis and predictions for the equilibrium phases of superfluid 3He infused into a low-density, homogeneous uniaxial aerogel. Ginzburg-Landau (GL) theory for a class of equal-spin-pairing (ESP) states in a medium with uniaxial anisotropy ... More
Effects of Magnetic Order on the Upper Critical Field of UPt$_3$Mar 18 1995I present a Ginzburg-Landau theory for hexagonal oscillations of the upper critical field of UPt$_3$ near $T_c$. The model is based on a $2D$ representation for the superconducting order parameter, $\vec{\eta}=(\eta_1,\eta_2)$, coupled to an in-plane ... More
Stochastic dynamics of N correlated binary variables and non-extensive statistical mechanicsJan 26 2016Feb 03 2016The non-extensive statistical mechanics has been applied to describe a variety of complex systems with inherent correlations and feedback loops. Here we present a dynamical model based on previously proposed static model exhibiting in the thermodynamic ... More
T Dwarf Discoveries by 2MASSJan 15 2001Over a dozen T dwarfs, brown dwarfs that exhibit methane absorption features at 1.6 and 2.2 $\micron$, have been discovered by the 2MASS survey. We discuss how the search for these objects has been made, point out some of the limitations of using near-infrared ... More
Publication and citation statistics for UK astronomersDec 28 2007This article presents a survey of publication and citation statistics for 835 UK professional astronomers: the majority of academics and contract researchers within the UK astronomical community. I provide histograms of these bibliometrics for the whole ... More
Screening and confinement in large N_f QCD_2 and in N=1 SYM_2Mar 16 1997The screening nature of the potential between external quarks in massless $SU(N_c)$ $QCD_2$ is derived using an expansion in $N_f$- the number of flavors. Applying the same method to the massive model, we find a confining potential. We consider the N=1 ... More
Dynamical density functional theory: phase separation in a cavity and the influence of symmetrySep 06 2005Consider a fluid composed of two species of particles, where the interparticle pair potentials $u_{11} = u_{22} \neq u_{12}$. On confining an equal number of particles from each species in a cavity, one finds that the average one body density profiles ... More
Two-dimensional fluid with competing interactions exhibiting microphase separation: theory for bulk and interfacial propertiesAug 29 2008Colloidal particles that are confined to an interface such as the air-water interface are an example of a two-dimensional fluid. Such dispersions have been observed to spontaneously form cluster and stripe morphologies in certain systems with isotropic ... More
An infrasolvmanifold which does not boundJun 20 2011May 17 2013Every 4-dimensional infrasolvmanifold $M$ with $\beta_1(M;\mathbb{Q})>0$ or which is flat or has one of the geometries $\mathbb{N}il^4$, $\mathbb{S}ol_{m,n}^4$, or $\mathbb{S}ol_0^4$ bounds. However there are non-orientable $\mathbb{S}ol_1^4$-manifolds ... More
Nonperturbative Tests of the Parent/Orbifold Correspondence in Supersymmetric Gauge TheoriesAug 05 1998It has been shown that a procedure analogous to orbifolding in string theory, when applied to certain large N field theories, leaves correlators invariant perturbatively. We test nonperturbative agreement of some aspects of the orbifolded and non-orbifolded ... More
Nucleon Mass Corrections to Spin Dependent Structure Functions and Relations Between their Twist-3 ContributionsMay 27 1999The nucleon mass corrections are calculated to all polarized structure functions for neutral and charged current deep inelastic scattering in lowest order in the coupling constant. The impact of the target mass corrections on the general relations between ... More