Results for "D. M. Zajac"

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Structure and zero-dimensional polariton spectrum of natural defects in GaAs/AlAs microcavitiesAug 01 2012We present a correlative study of structural and optical properties of natural defects in planar semiconductor microcavities grown by molecular beam epitaxy, which are showing a localized polariton spectrum as reported in Zajac et al., Phys. Rev. B 85, ... More
Parametric scattering of microcavity polaritons into ghost branchesOct 04 2012Polaritons of defined momentum and energy are excited resonantly on the lower polariton branch of a planar semiconductor microcavity in the strong coupling regime, and the spectrally and momentum resolved emission is analyzed. We observe ghost branches ... More
Scalable gate architecture for densely packed semiconductor spin qubitsJul 24 2016We demonstrate a 12 quantum dot device fabricated on an undoped Si/SiGe heterostructure as a proof-of-concept for a scalable, linear gate architecture for semiconductor quantum dots. The device consists of 9 quantum dots in a linear array and 3 single ... More
A Reconfigurable Gate Architecture for Si/SiGe Quantum DotsFeb 05 2015We demonstrate a reconfigurable quantum dot gate architecture that incorporates two interchangeable transport channels. One channel is used to form quantum dots and the other is used for charge sensing. The quantum dot transport channel can support either ... More
Circuit Quantum Electrodynamics Architecture for Gate-Defined Quantum Dots in SiliconOct 18 2016We demonstrate a hybrid device architecture where the charge states in a double quantum dot (DQD) formed in a Si/SiGe heterostructure are read out using an on-chip superconducting microwave cavity. A quality factor Q = 5,400 is achieved by selectively ... 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
A Coherent Spin-Photon Interface in SiliconOct 09 2017Electron spins in silicon quantum dots are attractive systems for quantum computing due to their long coherence times and the promise of rapid scaling using semiconductor fabrication techniques. While nearest neighbor exchange coupling of two spins has ... 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
Investigation of Mobility Limiting Mechanisms in Undoped Si/SiGe HeterostructuresMar 19 2015We perform detailed magnetotransport studies on two-dimensional electron gases (2DEGs) formed in undoped Si/SiGe heterostructures in order to identify the electron mobility limiting mechanisms in this increasingly important materials system. By analyzing ... 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
Growth and electronic and magnetic structure of iron oxide films on Pt(111)Nov 25 2011Nov 30 2011Ultrathin (111)-oriented polar iron oxide films were grown on a Pt(111) single crystal either by the reactive deposition of iron or oxidation of metallic iron monolayers. These films were characterized using low energy electron diffraction, scanning tunneling ... More
Direct evidence of the orbital contribution to the magnetic moment in AA'FeReO6 double perovskitesMar 15 2005Spin and orbital magnetic moments of Re in AA'FeReO6 double perovskites (A,A' = Ba, Sr, Ca) have been directly probed employing XMCD spectroscopy at the Re L2,3-edges. A considerable orbital magnetic moment is observed in all the studied compounds despite ... More
Screening nuclear field fluctuations in quantum dots for indistinguishable photon generationSep 03 2015Jan 08 2016A semiconductor quantum dot can generate highly coherent and indistinguishable single photons. However, intrinsic semiconductor dephasing mechanisms can reduce the visibility of two-photon interference. For an electron in a quantum dot, a fundamental ... More
Polariton states bound to defects in GaAs/AlAs planar microcavitiesNov 25 2011We report on polariton states bound to defects in planar GaAs/AlAs microcavities grown by molecular beam epitaxy. The defect types relevant for the spatial polariton dynamics in these structures are cross-hatch misfit dislocations, and point-like defects ... More
Calculations for electron-impact ionization of beryllium in the method of interacting configurations in the complex number representationAug 14 2016The beginning of the application of the method of interacting configurations in the complex number representation to the compound atomic systems has been presented. The spectroscopic characteristics of the Be atom in the problem of the electron-impact ... More
Indistinguishable single photons with flexible electronic triggeringJan 07 2016May 06 2016A key ingredient for quantum photonic technologies is an on-demand source of indistinguishable single photons. State-of-the-art indistinguishable single-photon sources typically employ resonant excitation pulses with fixed repetition rates, creating a ... More
Performance of a Quintuple-GEM Based RICH Detector PrototypeJan 14 2015Jun 27 2016Cerenkov technology is often the optimal choice for particle identification in high energy particle collision applications. Typically, the most challenging regime is at high pseudorapidity (forward) where particle identification must perform well at high ... More
Late-time evolution of the gravitating SkyrmionJun 23 2009We study the dynamics of spherically symmetric solutions in the Einstein Skyrme model. We focus our attention on generic long time evolution of initial data resulting in the formation of the B = 1 soliton, which plays the role of an attractor. We demonstrate ... More
Late-time tails of self-gravitating skyrmionsJan 26 2010Jan 25 2011We consider the long-time behaviour of spherically symmetric solutions in the Einstein-Skyrme model. Using nonlinear perturbation analysis we obtain the leading order estimation of the tail in the topologically trivial sector (B = 0) of the model. We ... More
Calculations for electron-impact ionization of magnesium and calcium atoms in the method of interacting configurations in the complex number representationJun 23 2017Next investigations in our program of transition from the He atom to the complex atoms description have been presented. The method of interacting configurations in the complex number representation is under consideration. The spectroscopic characteristics ... More
Spectral action for scalar perturbations of Dirac operatorsDec 17 2010We investigate the leading terms of the spectral action for odd-dimensional Riemannian spin manifolds with the Dirac operator perturbed by a scalar function. We calculate first two Gilkey-de Witt coefficients and make explicit calculations for the case ... More
Discrete Gauging in Coulomb branches of Three Dimensional $\mathcal{N}=4$ Supersymmetric Gauge TheoriesJul 09 2018Aug 15 2018This paper tests a conjecture on discrete non-Abelian gauging of 3d $\mathcal{N} = 4$ supersymmetric quiver gauge theories. Given a parent quiver with a bouquet of $n$ nodes of rank $1$, invariant under a discrete $S_n$ global symmetry, one can construct ... More
Polariton condensation in a planar microcavity with InGaAs quantum wellsJul 24 2014Polariton lattice condensates provide a platform for on chip quantum emulations. Interactions in extended polariton lattices are currently limited by the intrinsic photonic disorder of microcavities. Here, we fabricate a strain compensated planar GaAs/AlAs ... More
Contractible polyhedra in products of trees and absolute retracts in products of dendritesFeb 03 2011Dec 07 2012We show that a compact n-polyhedron PL embeds in a product of n trees if and only if it collapses onto an (n-1)-polyhedron. If the n-polyhedron is contractible and n\ne 3 (or n=3 and the Andrews-Curtis Conjecture holds), the product of trees may be assumed ... More
Institutionalization in Efficient Markets: The Case of Price BubblesAug 23 2016We seek to deepen understanding of the micro-foundations of institutionalization while contributing to a sociological theory of markets by investigating the puzzle of price bubbles in financial markets. We find that such markets, despite textbook conditions ... More
Computer assisted proof of Shil'nikov homoclinics: with application to the Lorenz-84 modelMay 25 2016We present a methodology for computer assisted proofs of Shil'nikov homoclinic intersections. It is based on geometric bounds on the invariant manifolds using rate conditions, and on propagating the bounds by an interval arithmetic integrator. Our method ... More
Minimally Unbalanced QuiversOct 02 2018Oct 08 2018We develop a classification of \emph{minimally unbalanced} $3d~\mathcal{N}=4$ quiver gauge theories. These gauge theories are important because the isometry group $G$ of their Coulomb branch contains a single factor, which is either a classical or an ... More
Majorana neutrino mass matrix with CP symmetry breakingApr 16 2012From the new existing data with not vanishing theta13 mixing angle we determine the possible shape of the Majorana neutrino mass matrix. We assume that CP symmetry is broken and all Dirac and Majorana phases are taken into account. Two possible approaches ... More
Terahertz-based attosecond metrology of relativistic electron beamsMay 05 2018Photons, electrons, and their interplay are at the heart of photonic devices and modern instruments for ultrafast science [1-10]. Nowadays, electron beams of the highest intensity and brightness are created by photoemission with short laser pulses, and ... More
Time-monitoring Observations of the Ro-Vibrational Overtone CO bands in Young StarsJun 11 2013We present near-IR spectra of a sample of T Tauri, Herbig Ae/Be, and FU Ori objects. Using the FSPEC instrument on the Bok 90-inch telescope, we obtained K-band spectra with a resolution of ~3500. Here we present spectra of the v=2->0 and v=3->1 bandheads ... More
The Type Ia Supernova 1998bu in M96 and the Hubble ConstantJun 12 1999We present optical and near-infrared photometry and spectroscopy of the type Ia SN 1998bu in the Leo I Group galaxy M96 (NGC 3368). The data set consists of 356 photometric measurements and 29 spectra of SN 1998bu between UT 1998 May 11 and July 15. The ... More
Time-monitoring Observations of Br$γ$ Emission from Young StarsNov 19 2014We present multiple epochs of near-IR spectroscopy for a sample of 25 young stars, including T Tauri, Herbig Ae/Be, and FU Ori objects. Using the FSPEC instrument on the Bok 90-inch telescope, we obtained K-band spectra of the BrGamma transition of hydrogen, ... More
A Model of Convergent Extension in Animal MorphogenesisDec 17 1999Jan 24 2000In this paper we argue that the pattern of cell movements in the morphogenetic process known as convergent extension can be understood as a energy minimization process, provided the cell-cell adhesive energy has a certain kind of anisotropy. This single ... More
Likelihood method and Fisher information in construction of physical modelsNov 21 2008The subjects of the paper are the likelihood method (LM) and the expected Fisher information (FI) considered from the point od view of the construction of the physical models which originate in the statistical description of phenomena. The master equation ... More
Late-time tails of wave maps coupled to gravityJun 16 2009We consider the late-time asymptotic behavior for solutions of Einstein's equations with the wave map matter. Solutions starting from small compactly supported $\ell$-equivariant initial data with $\ell\geq 1$ are shown to decay as $t^{-(2\ell+2)}$ at ... More
Collective Quadrupole Excitations in Transitional NucleiJun 27 2000The generalized Bohr Hamiltonian was used to describe the low-lying collective excitations in even-even isotopes of Ru, Pd, Te, Ba and Nd. The Strutinsky collective potential and cranking inertial functions were obtained using the Nilsson potential. The ... More
The low-lying quadrupole collective excitations of Ru and Pd isotopesFeb 16 1999Quadrupole excitations of even-even Ru and Pd isotopes are described within microscopic approach based on the general collective Bohr model which includes the effect of coupling with the pairing vibrations. The excitation energies and E2 transition probabilities ... More
Collective quadrupole excitations in the 50<Z,N<82 nuclei with the generalized Bohr HamiltonianMay 23 1998The generalized Bohr Hamiltonian is applied to a description of low-lying collective excitations in even-even isotopes of Te, Xe, Ba, Ce, Nd and Sm. The collective potential and inertial functions are determined by means of the Strutinsky method and the ... More
Li dynamics in carbon-rich polymer-derived SiCN ceramics probed by nuclear magnetic resonanceJan 08 2014We report $^{7}$Li, $^{29}$Si, and $^{13}$C NMR studies of two different carbon-rich SiCN ceramics SiCN-1 and SiCN-3 derived from the preceramic polymers polyphenylvinylsilylcarbodiimide and polyphenylvinylsilazane, respectively. From the spectral analysis ... More
Epsilon Aurigae: An improved spectroscopic orbital solutionJan 27 2010A rare eclipse of the mysterious object Epsilon Aurigae will occur in 2009-2011. We report an updated single-lined spectroscopic solution for the orbit of the primary star based on 20 years of monitoring at the CfA, combined with historical velocity observations ... More
Transport spectroscopy of disordered graphene quantum dots etched into a single graphene flakeJul 30 2013We present transport measurements on quantum dots of sizes 45, 60 and 80 nm etched with an Ar/O2-plasma into a single graphene sheet, allowing a size comparison avoiding effects from different graphene flakes. The transport gaps and addition energies ... More
Germanium Detector Response to Nuclear Recoils in Searching for Dark MatterMar 20 2012Aug 22 2012The discrepancies in claims of experimental evidence in the search for weakly interacting massive particle (WIMP) dark matter necessitate a model for ionization efficiency (the quenching factor) at energies below 10 keV. We have carefully studied the ... More
Magnetic field of a neutron star with color superconducting quark matter coreMay 10 2002The behaviour of the magnetic field of a neutron star with a superconducting quark matter core is investigated in the framework of the Ginzburg-Landau theory. We take into account the simultaneous coupling of the diquark condensate field to the usual ... More
Shape of Mixed Micelles: Cylinders or Spheres? Theoretical AnalysisMar 21 1998We develop a theoretical model for the solubilization of phospholipid bilayers by micelle-forming surfactants. Cylindrical micelles, disc-like micelles and spherical micelles are considered as alternative resultant structures. The main question addressed ... More
Hyperon Nonleptonic Weak Decays RevisitedNov 27 2000Nov 29 2000We first review the current algebra - PCAC approach to nonleptonic octet baryon 14 weak decay B (\to) (B^{\prime})(\pi) amplitudes. The needed four parameters are independently determined by (\Omega \to \Xi \pi),(\Lambda K) and (\Xi ^{-}\to \Sigma ^{-}\gamma) ... More
Halting Planetary MigrationNov 19 1999Jan 05 2000When Jupiter's Roche Lobe radius exceeded the scale height of the protoplanetary disk, Jupiter opened a gap in the disk. When the gap was wide enough, tidal torques from the disk interior and exterior to Jupiter were suppressed and migration continued ... More
High-field optically detected nuclear magnetic resonance in GaAsJan 26 2005A method for high-field optically detected nuclear magnetic resonance (ODNMR) is developed sensitive to 10**8 nuclei. Nuclear spin transitions are induced using a radio frequency coil and detected through Faraday rotation spectroscopy. Unlike conventional ... More
Dispersing the Gaseous Protoplanetary Disc and Halting Type II MigrationJun 28 2003More than 30 extra-solar Jupiter-like planets have shorter periods than the planet Mercury. It is generally accepted that they formed further out, and migrated inwards. In order to be driven by tidal torques from the gaseous disc, the disc exterior to ... More
On the Snow Line in Dusty Protoplanetary DisksNov 19 1999The snow line, in Hayashi's (1981) model, is where the temperature of a black body that absorbed direct sunlight and re-radiated as much as it absorbed, would be 170~K. It is usually assumed that the cores of the giant planets, e.g., Jupiter, form beyond ... More
Nilpotent Groups are RoundNov 11 2009We define a notion of roundness for finite groups. Roughly speaking, a group is round if one can order its elements in a cycle in such a way that some natural summation operators map this cycle into new cycles containing all the elements of the group. ... More
Excitation of non-radial stellar oscillations by gravitational waves: a first modelJun 24 2010Oct 17 2010The excitation of solar and solar-like g modes in non-relativistic stars by arbitrary external gravitational wave fields is studied starting from the full field equations of general relativity. We develop a formalism that yields the mean-square amplitudes ... More
Scaling and width distributions of parity conserving interfacesSep 20 2013Nov 28 2013We present an alternative finite-size approach to a set of parity conserving interfaces involving attachment, dissociation, and detachment of extended objects in 1+1 dimensions. With the aid of a nonlocal construct introduced by Barma and Dhar in related ... More
Theory and Phenomenology of Mixed Amphiphilic AggregatesMar 21 1998We give a short overview of existing approaches describing shapes and energetics of amphiphilic aggregates. In particular, we consider recent experimental data and theory in relation to mixed aggregates. We point out the outstanding questions deserving ... More
Spectral properties of the Holstein double-exchange model and application to manganitesNov 09 2001Jun 18 2002Calculations of one-electron spectral functions, optical conductivity and spin-wave energy in the Holstein double-exchange model are made using the many-body coherent potential approximation. Satisfactory agreement is obtained with angle-resolved photoemission ... More
Circumventing the axial anomalies and the strong CP problemMar 15 2005Dec 12 2005Many meson processes are related to the U_A(1) axial anomaly, present in the Feynman graphs where fermion loops connect axial vertices with vector vertices. However, the coupling of pseudoscalar mesons to quarks does not have to be formulated via axial ... More
Bypassing the axial anomaliesDec 09 2005Many meson processes are related to the U_A(1) axial anomaly, present in the Feynman graphs where fermion loops connect axial vertices with vector vertices. However, the coupling of pseudoscalar mesons to quarks does not have to be formulated via axial ... More
Chiral symmetry breaking via constituent quarks for qbarq pseudoscalar mesonsJul 18 2005We base our chiral symmetry approach on the quark-level linear sigma model Lagrangian. Then we review the Nambu--Goldstone theorem with vanishing pi, K, eta_8 masses. Next we dynamically generate the pi, K, eta_8 masses away from the chiral limit. Then ... More
Models of a protoplanetary disk forming in-situ the Galilean and smaller nearby satellites before Jupiter is fully formedJan 16 2019We fit an isothermal oscillatory density model of Jupiter's protoplanetary disk to the present-day Galilean and other nearby satellites and we determine the radial scale length of the disk, the equation of state and the central density of the primordial ... More
Comment on two papers claiming records for the lowest carrier concentration at which superconductivity has been observedApr 13 2016A recent paper and a preprint both claim records for the lowest carrier concentration at which superconductivity has been observed. However colleagues in Australia and I found evidence for superconductivity at concentrations of the order of at least a ... More
On Some Algebra and the Corresponding Analysis in the Pseudo-Riemannian Space with Signature 1,-1,-1,-1Sep 20 2013In this paper the certain 4-dimensional algebra in 4-dimensional pseudo-Riemannian space with signature (1, -1, -1, -1) is constructed. On the basis of this algebra the elements of the analysis, i.e. the theory of 4-dimensional functions of the 4-dimensional ... More
The X-ray Jets of Active GalaxiesDec 17 2008Jet physics is again flourishing as a result of Chandra's ability to resolve high-energy emission from the radio-emitting structures of active galaxies and separate it from the X-ray-emitting thermal environments of the jets. These enhanced capabilities ... More
On the L^2-Stokes theorem and Hodge theory for singular algebraic varietiesFeb 09 1999May 07 2002For a projective algebraic variety $V$ with isolated singularities, endowed with a metric induced from an embedding, we consider the analysis of the natural partial differential operators on the regular part of $V$. We show that, in the complex case, ... More
Parsec-scale morphology and spectral index distribution in faint high frequency peakersMay 02 2012We investigate the parsec-scale structure of 17 high frequency peaking radio sources from the faint HFP sample. VLBA observations were carried out at two adjacent frequencies, 8.4 and 15.3 GHz, both in the optically-thin part of the spectrum, to obtain ... More
Proper motion and apparent contraction in J0650+6001Mar 15 2010We present a multi-epoch and multi-frequency VLBI study of the compact radio source J0650+6001. In VLBI images the source is resolved into three components. The central component shows a flat spectrum, suggesting the presence of the core, while the two ... More
Constraining the nature of High Frequency Peakers. II. Polarization propertiesDec 19 2007Aims: The ``bright'' High Frequency Peakers (HFPs) sample is a mixture of blazars and intrinsically small and young radio sources. We investigate the polarimetric characteristics of 45 High Frequency Peakers, from the ``bright'' HFP sample, in order to ... More
Determination of the lowest energy structure of Ag$_8$ from first-principles calculationsSep 16 2005The ground-state electronic and structural properties, and the electronic excitations of the lowest energy isomers of the Ag$_8$ cluster are calculated using density functional theory (DFT) and time-dependent DFT (TDDFT) in real time and real space scheme, ... More
Tera-Leptons Shadows over Sinister UniverseJul 07 2005The role of Sinister Heavy Fermions in recent Glashow's SU(3)*SU(2)*SU(2)'*U(1) model is to offer in a unique frame relic Helium-like products (an ingenious candidate to the dark matter puzzle), a solution to the See-Saw mechanism for light neutrino masses ... More
Metropolis Methods for Quantum Monte Carlo SimulationsJun 25 2003Since its first description fifty years ago, the Metropolis Monte Carlo method has been used in a variety of different ways for the simulation of continuum quantum many-body systems. This paper will consider some of the generalizations of the Metropolis ... More
On Auxiliary Fields in BF TheoriesAug 11 2004Sep 14 2004We discuss the structure of auxiliary fields for non-Abelian BF theories in arbitrary dimensions. By modifying the classical BRST operator, we build the on-shell invariant complete quantum action. Therefore, we introduce the auxiliary fields which close ... More
QCD Sum Rule for 1/2- BaryonsNov 14 1996Feb 17 1997The masses of the flavor octet and singlet baryons with negative parity and spin 1/2 are calculated using the QCD sum rule. We find that the chiral symmetry breaking vacuum condensates cause the mass splitting of the positive and negative baryons. The ... More
Decay properties of a class of doubly charged Higgs bosonsOct 04 2012Oct 11 2012We study the leptonic decays of a doubly charged Higgs bosons class which is predicted by a model based on the SU(3)_C\otimesSU(2)_L\otimesU(1)_N electroweak gauge symmetry. In contrast to other models, decays into taus are largely dominant (99.5 % or ... More
One-loop potential with scale invariance and effective operatorsMay 18 2016We study quantum corrections to the scalar potential in classically scale invariant theories, using a manifestly scale invariant regularization. To this purpose, the subtraction scale $\mu$ of the dimensional regularization is generated after spontaneous ... More
A Microcalorimeter and Bolometer ModelApr 22 2003The standard non-equilibrium theory of noise in ideal bolometers and microcalorimeters fails to predict the performance of real devices due to additional effects that become important at low temperature. In this paper we extend the theory to include the ... More
Incidence DivisorMar 05 2003The aim of this paper is to prove an important generalization of the construction of the Incidence Divisor given in [BMg]. Let Z be a complex manifold and (X_{s})_{s\in S}an family of n-cycles (not necessarily compact) in Z parametrized by reduced complex ... More
Locally Disordered Lattices in Strong ac Electric FieldsJul 21 1993We develop a formalism to study the role of local defects in tight binding systems in the presence of a strong external ac electric field. It is found that the appearance and disappearance of localized states, as well as their localization lengths, can ... More
Quantum Tunneling and Unitarity Features of an S-matrix for Gravitational CollapseSep 24 2009Starting from the semiclassical reduced-action approach to transplanckian scattering by Amati, Veneziano and one of us and from our previous quantum extension of that model, we investigate the S-matrix expression for inelastic processes by extending to ... More
The BFKL Equation at Next-to-Leading Order and BeyondDec 15 1998On the basis of a renormalization group analysis of the kernel and of the solutions of the BFKL equation with subleading corrections, we propose and calculate a novel expansion of a properly defined effective eigenvalue function. We argue that in this ... More
Thermodynamically consistent equilibrium properties of normal-liquid Helium-3Jun 15 1999Sep 02 2005The high-precision data for the specific heat C_{V}(T,V) of normal-liquid Helium-3 obtained by Greywall, taken together with the molar volume V(T_0,P) at one temperature T_0, are shown to contain the complete thermodynamic information about this phase ... More
Sommerfeld effect in heavy quark chemical equilibrationOct 23 2012The chemical equilibration of heavy quarks in a quark-gluon plasma proceeds via annihilation or pair creation. For temperatures T much below the heavy quark mass M, when kinetically equilibrated heavy quarks move very slowly, the annihilation in the colour ... More
Heavy quark chemical equilibration rate as a transport coefficientMay 22 2012Jul 31 2012Motivated by indications that heavy (charm and bottom) quarks interact strongly at temperatures generated in heavy ion collision experiments, we suggest a non-perturbative definition of a heavy quark chemical equilibration rate as a transport coefficient. ... More
The quantitative condition is necessary in guaranteeing the validity of the adiabatic approximationApr 19 2010The usual quantitative condition has been widely used in the practical applications of the adiabatic theorem. However, it had never been proved to be sufficient or necessary before. It was only recently found that the quantitative condition is insufficient, ... More
Negative Observations in Quantum MechanicsDec 06 1999In quantum mechanics, it is possible to make observations that affect physical entities without there being a physical interaction between the observer and the physical entity measured. Epstein (1945) and Renninger (1960) discussed this situation, and ... More
The Tcc = DD* molecular stateMay 21 2004Oct 04 2004We show that the molecule-like configuration of DD^* enables weak binding with two realistic potential models (Bhaduri and Grenoble AL1). Three-body forces may increase the binding and strengthen the cc diquark configuration. As a signature we propose ... More
Comment on ``Using Fermi Statistics to Create Strongly Coupled Ion Plasmas in Atom Traps''Sep 28 2001The fermionic exchange energy of ultracold ions is computed. It is shown that this effect allows to increase the ion coupling in traps by about an order of magnitude compared to the classical case.
The Orientation of Local Spatial Reference Frames in Quantum TeleportationJul 19 2000Oct 26 2000Bennett et al.'s original article on quantum teleportation did not address explicitly synchronizing the orientation of the local spatial reference frames from and to which teleportaton occurs where the state teleported is spin 1/2 along the z axis. They ... More
Irreversibility and Measurement in Quantum MechanicsFeb 28 2000Irreversibility is often considered to characterize measurements in quantum mechanics. Fundamental problems with this characterization are addressed. First, whether a measurement is made in quantum mechanics is an arbitrary decision on the part of the ... More
An Essay on the Relationship Between the Mind and the Physical WorldFeb 16 2000Feb 16 2003A non-technical argument is presented that there is a link between the mind and the physical world in modern physics. Special relativity, general relativity, quantum mechanics, statistical mechanics, and other areas of physics are explored. Each area ... More
Generalization of Einstein-Lovelock theory to higher order dilaton gravityApr 10 2007Oct 19 2007A higher order theory of dilaton gravity is constructed as a generalization of the Einstein-Lovelock theory of pure gravity. Its Lagrangian contains terms with higher powers of the Riemann tensor and of the first two derivatives of the dilaton. Nevertheless, ... More
The field and Killing spinor equations of M-theory and type IIA/IIB supergravity in coordinate-free notationJun 30 2016Jul 19 2016We review the actions of the supergravity theory in eleven dimensions as well as the type IIA and IIB supergravities in ten dimensions and derive the bosonic equations of motion in a coordinate-free notation. We also consider the existence of supersymmetries ... More
The Crumpling Transition RevisitedDec 08 1992The ``crumpling" transition, between rigid and crumpled surfaces, has been object of much discussion over the past years. The common lore is that such transition should be of second order. However, some lattice versions of the rigidity term on fixed connectivity ... More
Finite-Difference Implementation of Inviscid Separated Flows with Infinitely-Long Cusp-Ended Stagnation Zone around Circular CylinderJun 27 1998The classical Helmholtz problem is applied for modelling and numerical investigation of inviscid cusp-ended separated flow around circular cylinder. Two coordinate systems are used: polar for initial calculations and parabolic as topologically most suited ... More
Two-Loop ${\cal O}(αα_s)$ Corrections to the On-Shell Fermion Propagator in the Standard ModelDec 08 2005In this paper we consider mixed two-loop electroweak corrections to the top quark propagator in the Standard Model. In particular, we compute the on-shell renormalization constant for the mass and wave function, which constitute building blocks for many ... More
Reply to Comment hep-th/9509028Sep 27 1995This is a reply to the above comment (hep-th/9509028). We argue that QED displays a class of symmetries which may be used to select out the various velocity dependent superselection sectors.
EROs in the EIS Fields. I: The AXAF (Chandra) Deep FieldApr 17 2000The publicly available EIS-DEEP optical-NIR data for the AXAF (Chandra) Deep Field have been used to construct samples of Extremely Red Objects (EROs) using various single-band and multi-band color criteria. In this work we define as EROs objects with ... More
The Nature and Observability of ProtogalaxiesMay 08 1996I discuss recent theoretical work on the formation and evolution of galaxies paying particular attention to the ability of current models to make detailed comparisons with observations of the galaxy population both nearby and at high redshift. These models ... More
The Physical Origin of Galaxy Scaling RelationsFeb 25 1997A standard paradigm is now available for the recent evolution (z < 10) of structure on galactic and larger scales. Most of the matter is assumed to be dark and dissipationless and to cluster hierarchically from gaussian initial conditions. Gas moves under ... More
Supernova and CosmologyOct 31 2000These lecture notes intend to form a short pedagogical introduction to the use of typical type Ia-Supernovae (hereafter SNIa) as standard candles to determine the energy density of the universe. Problems of principle for taking SNIa as cosmological probes ... More
Transitivity degrees of countable groups and acylindrical hyperbolicityJan 17 2015We prove that every countable acylindrically hyperbolic group admits a highly transitive action with finite kernel. This theorem uniformly generalizes many previously known results and allows us to answer a question of Garion and Glassner on the existence ... More
Induced quasi-cocycles on groups with hyperbolically embedded subgroupsMar 24 2012Mar 05 2013Let G be a group, H a hyperbolically embedded subgroup of G, V a normed G-module, U an H-invariant submodule of V. We propose a general construction which allows to extend 1-quasi-cocycles on H with values in U to 1-quasi-cocycles on G with values in ... More