Results for "P. H. Lundow"

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The scaling window of the 5D Ising model with free boundary conditionsJan 15 2016Jan 27 2016The five-dimensional Ising model with free boundary conditions has recently received a renewed interest in a debate concerning the finite-size scaling of the susceptibility near the critical temperature. We provide evidence in favour of the conventional ... More
Non-vanishing boundary effects and quasi-first order phase transitions in high dimensional Ising modelsOct 28 2010In order to gain a better understanding of the Ising model in higher dimensions we have made a comparative study of how the boundary, open versus cyclic, of a d-dimensional simple lattice, for d=1,...,5, affects the behaviour of the specific heat C and ... More
Complete graph asymptotics for the Ising and random cluster models on 5D grids with cyclic boundaryAug 09 2014The finite size scaling behaviour for the Ising model in five dimensions, with either free or cyclic boundary, has been the subject for a long running debate. The older papers have been based on ideas from e.g. field theory or renormalization. In this ... More
Reconstruction of the finite size canonical ensemble from incomplete micro-canonical dataDec 18 2006In this paper we discuss how partial knowledge of the density of states for a model can be used to give good approximations of the energy distributions in a given temperature range. From these distributions one can then obtain the statistical moments ... More
On the $p,q$-binomial distribution and the Ising modelJan 17 2010A completely new approach to the Ising model in 1 to 5 dimensions is developed. We employ $p,q$-binomial coefficients, a generalisation of the binomial coefficients, to describe the magnetisation distributions of the Ising model. For the complete graph ... More
Finite size scaling of the 5D Ising model with free boundary conditionsAug 23 2014There has been a long running debate on the finite size scaling for the Ising model with free boundary conditions above the upper critical dimension, where the standard picture gives a $L^2$ scaling for the susceptibility and an alternative theory has ... More
Critical behaviour of the Ising model on the 4-dimensional latticeFeb 14 2012In this paper we investigate the nature of the singularity of the Ising model of the 4-dimensional cubic lattice. It is rigorously known that the specific heat has critical exponent $\alpha=0$ but a non-rigorous field-theory argument predicts an unbounded ... More
Efficient computation of permanents, with applications to boson sampling and random matricesApr 12 2019In order to verify the results of Boson sampling experiments one must be able to compute the permanent of the associated Hamiltonians. Here we first present a freely available software package, available in both serial and parallel versions. As part of ... More
The discontinuity of the specific heat for the 5D Ising modelFeb 26 2015In this paper we investigate the behaviour of the specific heat around the critical point of the Ising model in dimension 5 to 7. We find a specific heat discontinuity, like that for the mean field Ising model, and provide estimates for the left and right ... More
Critical scaling to infinite temperatureMar 23 2011Three dimensional Ising model ferromagnets on different lattices with nearest neighbor interactions, and on simple cubic lattices with equivalent interactions out to further neighbors, are studied numerically. The susceptibility data for all these systems ... More
The bimodal and Gaussian Ising Spin Glasses in dimension two revisitedJun 23 2015Aug 27 2015A new analysis is given of numerical simulation data on the archetype square lattice Ising Spin Glasses (ISG) with a bimodal ($\pm J$) and Gaussian interaction distributions. It is well established that the ordering temperature of both models is zero. ... More
The Ising Spin Glass in dimension four; non-universalityFeb 09 2014Aug 04 2014Extensive simulations are made on Ising Spin Glasses (ISG) with Gaussian, Laplacian and bimodal interaction distributions in dimension four. Standard finite size scaling analyses near and at criticality provide estimates of the critical inverse temperatures ... More
The Ising Spin Glass in dimension five: link overlapsOct 15 2012Oct 19 2012Extensive simulations are made of the link overlap in five dimensional Ising Spin Glasses (ISGs) through and below the ordering transition. Moments of the mean link overlap distributions (the kurtosis and the skewness) show clear critical maxima at the ... More
$W$ : an alternative phenomenological coupling parameter for model systemsApr 11 2010We introduce a parameter $W(\beta,L)= (\pi\,\langle |m| \rangle^2/\langle m^2 \rangle - 2)/(\pi-2)$ which like the kurtosis (Binder cumulant) is a phenomenological coupling characteristic of the shape of the distribution $p(m)$ of the order parameter ... More
Ising Spin Glasses in dimension fiveJun 09 2016Ising spin glass models with bimodal, Gaussian, uniform and Laplacian interaction distributions in dimension five are studied through detailed numerical simulations. The data are analyzed in both the finite-size scaling regime and the thermodynamic limit ... More
Non-self-averaging in Ising spin glasses; hyperuniversalityAug 13 2015Ising spin glasses with bimodal and Gaussian near-neighbor interaction distributions are studied through numerical simulations. The non-self-averaging (normalized inter-sample variance) parameter $U_{22}(T,L)$ for the spin glass susceptibility (and for ... More
Critical exponents of the binomial Ising Spin Glass in dimension four; non-universalityOct 13 2013Extensive simulations are made on the bimodal Ising Spin Glass (ISG) in dimension four. The transition temperature is established using a combination of standard finite size scaling and of thermodynamic derivative peak data. Measurements in the thermodynamic ... More
The Fortuin-Kasteleyn and Damage Spreading transitions in Random bond Ising latticesApr 30 2012Aug 16 2012The Fortuin-Kasteleyn and heat-bath damage spreading temperatures T_{FK}(p) and T_{ds}(p) are studied on random bond Ising models of dimension two to five and as functions of the ferromagnetic interaction probability p; the conjecture that T_{ds}(p) ~ ... More
An extended scaling analysis of the S=1/2 Ising ferromagnet on the simple cubic latticeOct 29 2010Jan 31 2011It is often assumed that for treating numerical (or experimental) data on continuous transitions the formal analysis derived from the Renormalization Group Theory can only be applied over a narrow temperature range, the "critical region"; outside this ... More
Evidence for non-universal scaling in dimension four Ising spin glassesNov 08 2014Apr 03 2015The critical behavior of the Binder cumulant for Ising spin glasses in dimension four are studied through simulation measurements. Data for the bimodal interaction model are compared with those for the Laplacian interaction model. Special attention is ... More
Critical exponents in Ising Spin GlassesJul 19 2013Extensive simulations are made of the spin glass susceptibility and correlation length in five dimension Ising Spin Glasses (ISGs) with Gaussian and bimodal interaction distributions. Once the transition temperature is accurately established using a standard ... More
Link overlaps at Criticality and Universality in Ising Spin GlassesFeb 05 2013May 03 2013Extensive simulations are made of link and spin overlaps in four and five dimensional Ising Spin Glasses (ISGs). Moments and moment ratios of the mean link overlap distributions (the variance, the kurtosis and the skewness) show clear critical behavior ... More
The Ising ferromagnet in dimension five: link and spin overlapsNov 08 2012Jan 11 2013In the simple [hyper]cubic five dimension near neighbor interaction Ising ferromagnet, extensive simulation measurements are made of the link overlap and the spin overlap distributions. These "two replica" measurements are standard in the Spin Glass context ... More
Ising Spin Glasses and Renormalization Group Theory: the Binder cumulantFeb 10 2016Jul 13 2016Numerical data on scaling of the normalized Binder cumulant and the normalized correlation length are shown for the Thermodynamic limit regime, first for canonical Ising ferromagnet models and then for a range of Ising spin glass models. A fundamental ... More
The Ising Spin Glass in dimension fourJul 07 2015The critical behaviors of the bimodal and Gaussian Ising spin glass (ISG) models in dimension four are studied through extensive numerical simulations, and from an analysis of high temperature series expansion (HTSE) data of Klein {\it et al.} (1991). ... More
Isotope effect on superconductivity in Josephson coupled stripes in underdoped cupratesSep 26 2007Inelastic neutron scattering data for YBaCuO as well as for LaSrCuO indicate incommensurate neutron scattering peaks with incommensuration $\delta(x)$ away from the $(\pi,\pi)$ point. $T_c(x)$ can be replotted as a linear function of the incommensuration ... More
The 1-vertex transfer matrix and accurate estimation of channel capacityFeb 28 2006Jun 08 2009The notion of a 1-vertex transfer matrix for multi-dimensional codes is introduced. It is shown that the capacity of such codes, or the topological entropy, can be expressed as the limit of the logarithm of spectral radii of 1-vertex transfer matrices. ... More
Validations of the Asymptotic Matching ConjecturesFeb 28 2006Apr 11 2008In this paper we review the asymptotic matching conjectures for $r$-regular bipartite graphs, and their connections in estimating the monomer-dimer entropies in $d$-dimensional integer lattice and Bethe lattices. We prove new rigorous upper and lower ... More
Renormalization of the Polyakov loop with gradient flowSep 25 2015Nov 24 2015We use the gradient flow for the renormalization of the Polyakov loop in various representations. Using 2+1 flavor QCD with highly improved staggered quarks and lattices with temporal extents of $N_\tau=6$, $8$, $10$ and $12$ we calculate the renormalized ... More
An Overdensity of Extremely Red Objects Around Faint Mid-IR galaxiesMay 04 2004We have searched for Extremely Red Objects (EROs) around faint mid-IR selected galaxies in ELAIS fields. We find a significant overdensity, by factors of 2 to 5, of these EROs compared to field EROs in the same region and literature random field ERO counts. ... More
Number Counts of Bright Extremely Red Objects: Evolved Massive Galaxies at z~1Apr 06 2004We present results on number counts of Extremely Red Objects (EROs) in a 2850 arcmin^2 near-infrared survey performed in European Large Area ISO Survey (ELAIS) fields at K<17.5. Counts of EROs are extended to brighter levels than available previously, ... More
On the Analytic Structure of the Quark Self-Energy in Nambu-Jona- Lasinio ModelsAug 25 1993The self-energy of quarks is investigated for various models which are inspired by the Nambu--Jona-Lasinio (NJL) model. Including, beyond the Hartree-Fock approximation, terms up to second-order in the quark interaction, the real and imaginary parts of ... More
Microscopic study of superdeformation in the A=150 mass regionOct 06 1995The cranked Hartree-Fock-Bogoliubov method presented in previous studies of superdeformed bands in Hg and Pb isotopes is applied to the study of superdeformed bands in Gd150, Dy152, Dy151 and Tb151. The same density-dependent zero-range pairing interaction ... More
Low energy threshold corrections to neutrino masses and mixing anglesOct 17 2001We compute the low energy threshold corrections to neutrino masses and mixing in the Standard Model (SM) and its minimal supersymmetric version, using the effective theory technique. We demonstrate that they stabilize the renormalization group (RG) running ... More
Significance Tests in Climate ScienceMar 15 2010A large fraction of papers in the climate literature includes erroneous uses of significance tests. A Bayesian analysis is presented to highlight the meaning of significance tests and why typical misuse occurs. It is concluded that a significance test ... More
Neutrino Mass Differences and Nonunitarity of Neutrino Mixing Matrix from Interfering Recoil IonsMar 20 2008Oct 06 2009We show that the recent observation of the time modulation of two-body weak decays of heavy ions reveals the mass content of the electron neutrinos via interference patterns in the recoiling ion wave function. From the modulation period we derive the ... More
Large sample-to-sample fluctuations of the nonequilibrium critical current through mesoscopic Josephson junctionsApr 12 2000We present a theory for the nonequilibrium current in a mesoscopic Josephson junction which is coupled to a normal electron reservoir, and apply it to a chaotic junction. Large sample-to-sample fluctuations of the critical current $I_{\rm c}$ are found, ... More
Theory of Coherent Raman Superradiance Imaging of Condensed Bose GasesFeb 14 2006Oct 17 2006We model the off-resonant superradiant Raman scattering of light from a cigar-shaped atomic Bose-Einstein condensate. Absorption images of transmitted light serve as a direct probe of long range coherence in the condensate. Our multimode theory is in ... More
Creating macroscopic atomic EPR states from Bose condensatesJul 05 2000We present a scheme for creating quantum entangled atomic states through the coherent spin-exchange collision of a spinor Bose-Einstein condensate. The state generated possesses macroscopic Einstein-Podolsky-Roson correlation and the fluctuation in one ... More
Giant outflows in z~2 radio galaxies: The smoking gun of AGN feedback in the early universeJun 16 2009Jun 19 2009AGN feedback is now a major component of models of galaxy evolution. Using near-infrared imaging spectroscopy on the VLT we identify kpc-sized outflows of few x 10^10 M_s of ionized gas in powerful radio galaxies at z~2-3. Velocity fields are consistent ... More
Strangeness Production in AA and pp CollisionsJan 07 2016Boost-invariant hadron production in high energy collisions occurs in causally disconnected regions of finite space-time size. As a result, globally conserved quantum numbers (charge, strangeness, baryon number) are conserved locally in spatially restricted ... More
Causality Constraints on Hadron Production In High Energy CollisionsOct 25 2013For hadron production in high energy collisions, causality requirements lead to the counterpart of the cosmological horizon problem: the production occurs in a number of causally disconnected regions of finite space-time size. As a result, globally conserved ... More
Spin-Wave Resonance Model of Surface Pinning in Ferromagnetic Semiconductor (Ga,Mn)As Thin FilmsNov 22 2013Jan 08 2014The source of spin-wave resonance (SWR) in thin films of the ferromagnetic semiconductor (Ga,Mn)As is still under debate: does SWR stem from the \emph{surface} anisotropy (in which case the surface inhomogeneity (SI) model would apply), or does it originate ... More
Scattering states of coupled valence-band holes in point defect potential derived from variable phase theoryOct 31 2006In this article we present a method to compute the scattering states of holes in spherical bands in the strong spin-orbit coupling regime. More precisely, we calculate scattering phase shifts and amplitudes of holes induced by defects in a semiconductor ... More
Topology and the Dirac Operator Spectrum in Finite-Volume Gauge TheoriesMar 11 1999Mar 17 1999The interplay between between gauge-field winding numbers, theta-vacua, and the Dirac operator spectrum in finite-volume gauge theories is reconsidered. To assess the weight of each topological sector, we compare the mass-dependent chiral condensate in ... More
AC susceptibility of YBa2Cu3O7-d superconducting thin film in a perpendicular fieldNov 30 2002The temperature dependence of ac susceptibility of YBCO thin film was measured as a function of frequency and ac field amplitude in a field perpendicular to the film plane. We show that all measured ac susceptibility curves can be caled into a single ... More
Constraints on low energy supersymmetryNov 25 1997We review the available constraints on the low energy supersymmetry. The bulk of the electroweak data is well screened from supersymmetric loop effects, due to the structure of the theory, even with superpartners generically light, ${\cal O}(M_Z)$. The ... More
Probability distribution of the order parameter in the directed percolation universality classSep 09 2012The probability distributions of the order parameter for two models in the directed percolation universality class were evaluated. Monte Carlo simulations have been performed for the one-dimensional generalized contact process and the Domany-Kinzel cellular ... More
Exact perturbative solution of the Kondo problemJun 22 1995We explicitly evaluate the infinite series of integrals that appears in the "Anderson-Yuval" reformulation of the anisotropic Kondo problem in terms of a one-dimensional Coulomb gas. We do this by developing a general approach relating the anisotropic ... More
Numerical calculation of linear modes in stellar disksMar 18 1996We present a method for solving the two-dimensional linearized collisionless Boltzmann equation using Fourier expansion along the orbits. It resembles very much solutions present in the literature, but it differs by the fact that everything is performed ... More
Quiver Gauge Theory and Unification at About 4 TeVFeb 08 2003The use of the AdS/CFT correspondence to arrive at quiver gauge field theories is dicussed, focusing on the orbifolded case without supersymmetry. An abelian orbifold with the finite group $Z_{p}$ can give rise to a $G = SU(N)^p$ gauge group with chiral ... More
Application of Conformal Gauge Theories Derived from Field-String DualityAug 25 1999In this article I first give an abbreviated history of string theory and then describe the recently-conjectured field-string duality. This suggests a class of nonsupersymmetric gauge theories which are conformal (CGT) to leading order of 1/N and some ... More
ADS/CFT String Duality and Conformal Gauge Field TheoriesDec 14 1998Compactification of Type IIB superstring on an $AdS_5 \times S^5/\Gamma$ background leads to SU(N) gauge field theories with prescribed matter representations. In the 't Hooft limit of large N such theories are conformally finite. For finite N and broken ... More
Dark Matter Candidate from ConformalityJul 17 2006Sep 26 2006Abelian quiver gauge theories provide candidates for the conformality approach to physics beyond the standard model which possess novel cancellation mechanisms for quadratic divergences. A $Z_2$ symmetry (R parity) can be imposed and leads naturally to ... More
Probing Matter Radii of Neutron-Rich Nuclei by Antiproton ScatteringFeb 21 2005We propose to use antiprotons to investigate the sizes of stable and neutron-rich exotic nuclei by measurements of the $\pbar A$ absorption cross section along isotopic chains in inverse kinematics. The expected effects are studied theoretically in a ... More
Flops, Type III contractions and Gromov-Witten invariants on Calabi-Yau threefoldsJul 09 1997Jul 20 1998We investigate Gromov-Witten invariants associated to exceptional classes for primitive birational contractions on a Calabi-Yau threefold X. It was observed in a previous paper that these invariants are locally defined, in that they can be calculated ... More
Star formation in grand-design, spiral galaxies. Young, massive clusters in the near-infraredApr 25 2012Deep, near-infrared JHK-maps were observed for 10 nearby, grand-design, spiral galaxies using HAWK-I/VLT to study the distribution of young stellar clusters in them and thereby determine whether strong spiral perturbations can influence star formation. ... More
Boundedness questions for Calabi-Yau threefoldsJun 05 2017May 09 2018In this paper, we study boundedness questions for (simply-connected) smooth Calabi-Yau threefolds. The diffeomorphism class of such a threefold is known to be determined up to finitely many possibilities by the integral middle cohomology and two integral ... More
Iteratively algebraic ordersOct 26 2008Jan 02 2010A short proof of a theorem of M.H. Albert, and its application to lattices.
Why scientific publications should be anonymousDec 16 2015Numerous studies have revealed biases within the scientific communication system and across all scientific fields. For example, already prominent researchers receive disproportional credit compared to their (almost) equally qualified colleagues -- because ... More
Comment on Path Integral Derivation of Schrödinger Equation in Spaces with Curvature and TorsionApr 27 1996We present a derivation of the Schr\"odinger equation for a path integral of a point particle in a space with curvature and torsion which is considerably shorter and more elegant than what is commonly found in the literature.
Anholonomic Transformations of Mechanical Action PrincipleMay 21 1996We exhibit the transformation properties of the mechanical action principle under anholonomic transformations. Using the fact that spaces with torsion can be produced by anholonomic transformations we derive the correct action principle in these spaces ... More
New Action Principle for Classical Particle Trajectories in Spaces with TorsionMar 11 1995To comply with recent developments of path integrals in spaces with curvature and torsion we find the correct variational principle for the classical trajectories. Although the action depends only on the length, the trajectories are {\em autoparallels} ... More
Renormalization Group in Quantum MechanicsApr 03 2000We establish the renormalization group equation for the running action in the context of a one quantum particle system. This equation is deduced by integrating each fourier mode after the other in the path integral formalism. It is free of the well known ... More
The pre-history of quantum computationFeb 17 2004Nov 16 2004The main ideas behind developments in the theory and technology of quantum computation were formulated in the late 1970s and early 1980s by two physicists in the West and a mathematician in the former Soviet Union. It is not generally known in the West ... More
Hawking-Unruh Hadronization and Strangeness Production in High Energy CollisionsMar 14 2014The thermal multihadron production observed in different high energy collisions poses many basic problems: why do even elementary, $e^+e^-$ and hadron-hadron, collisions show thermal behaviour? Why is there in such interactions a suppression of strange ... More
Slavnov-Taylor identities in Coulomb gauge Yang-Mills theoryDec 10 2008The Slavnov-Taylor identities of Coulomb gauge Yang-Mills theory are derived from the (standard, second order) functional formalism. It is shown how these identities form closed sets from which one can in principle fully determine the Green's functions ... More
On the existence conditions of surface spin wave modes in (Ga,Mn)As thin filmsDec 16 2015Spin-wave resonance (SWR) is a newly emerged method for studying surface magnetic anisotropy and surface spin-wave modes (SSWMs) in (Ga,Mn)As thin films. The existence of SSWMs in (Ga,Mn)As thin films has recently been reported in the literature; SSWMs ... More
Exotic Quantum Criticality in One-Dimensional Coupled Dipolar Bosons TubesFeb 29 2012Jul 15 2012The competition between intertube hopping processes and density-density interactions is investigated in one-dimensional quantum dipolar bosons systems of N coupled tubes at zero temperature. Using a phenomenological bosonization approach, we show that ... More
Fragmentation in Massive Star FormationFeb 20 2004Feb 20 2004Studies of evolved massive stars indicate that they form in a clustered mode. During the earliest evolutionary stages, these regions are embedded within their natal cores. Here, we show high-spatial-resolution interferometric dust continuum observations ... More
What is the mass of the lightest supersymmetric Higgs boson?Feb 27 1997After reviewing briefly the upper bounds on the mass of the lightest Higgs boson in the most general unconstrained minimal supersymmetric extension of the Standard Model, we discuss various arguments which reduce the parameter space of the model and give ... More
Hyperelliptic curves for multi-channel quantum wires and the multi-channel Kondo problemSep 18 1998We study the current in a multi-channel quantum wire and the magnetization in the multi-channel Kondo problem. We show that at zero temperature they can be written simply in terms of contour integrals over a (two-dimensional) hyperelliptic curve. This ... More
Deriving Boundary S MatricesFeb 09 1994We show how to derive exact boundary $S$ matrices for integrable quantum field theories in 1+1 dimensions using lattice regularization. We do this calculation explicitly for the sine-Gordon model with fixed boundary conditions using the Bethe ansatz for ... More
Differential equations and duality in massless integrable field theories at zero temperatureApr 12 1999Functional relations play a key role in the study of integrable models. We argue in this paper that for massless field theories at zero temperature, these relations can in fact be interpreted as monodromy relations. Combined with a recently discovered ... More
The stability of uniformly rotating stellar disksMay 05 1995We explore a series expansion method to calculate the modes of oscillations for a variety of uniformly rotating finite disks, either with or without a dark halo. Since all models have the same potential, this survey focuses on the role of the distribution ... More
On the kinematic signature of a central Galactic bar in observed star samplesJan 26 1998A quasi self-consistent model for a barred structure in the central regions of our Galaxy is used to calculate the signature of such a triaxial structure on the kinematical properties of star samples. We argue that, due to the presence of a velocity dispersion, ... More
Is the Cosmological Constant Non-Zero?Jan 04 1999There is a discussion of the temperature anisotropy of the cosmic background radiation and of how the first Doppler peak depends on the different contributions to the vacuum energy density. An analytic calculation agrees well with numerical studies and ... More
Generalizations of the thermal Bogoliubov transformationApr 21 1993The thermal Bogoliubov transformation in thermo field dynamics is generalized in two respects. First, a generalization of the $\alpha$--degree of freedom to tilde non--conserving representations is considered. Secondly, the usual $2\times2$ Bogoliubov ... More
Relative Convex Hull Determination from Convex Hulls in the PlaneApr 29 2016A new algorithm for the determination of the relative convex hull in the plane of a simple polygon A with respect to another simple polygon B which contains A, is proposed. The relative convex hull is also known as geodesic convex hull, and the problem ... More
Statistics of young starforming complexes in spiral galaxies using NIR photometrySep 02 2008All slightly extended sources were identified on deep K-band maps of 46 spiral galaxies reaching at least K=20.3 mag/arcsec2 at a signal-to-noise level of 3. The galaxies had inclination angles <65 deg and linear resolutions <100 pc with seeing better ... More
Symplectic Deformations of Calabi-Yau threefoldsJul 09 1997This manuscript from August 1995 (revised February 1996) studies the Kaehler cone of Calabi-Yau threefolds via symplectic methods. For instance, it is shown that if two Calabi-Yau threefolds are general in complex moduli and are symplectic deformations ... More
A Z-Monitor to Calibrate Higgs Production via Vector Boson Fusion with Rapidity Gaps at the LHCApr 10 2003We study central Z-boson production accompanied by rapidity gaps on either side as a way to gauge Higgs weak boson fusion production at the LHC. We analyse the backgrounds for the bb-decay mode and show that these can be substantially reduced. Special ... More
Nonequilibrium dynamical mean-field theory of a strongly correlated systemFeb 04 2002We present a generalized dynamical mean-field approach for the nonequilibrium physics of a strongly correlated system in the presence of a time-dependent external field. The Keldysh Green's function formalism is used to study the nonequilibrium problem. ... More
How to accurately determine a saturation magnetization of the sample in a ferromagnetic resonance experiment?Jan 04 2019The phenomenon of ferromagnetic resonance (FMR) is still being exploited for determining the magnetocrystalline anisotropy constants of magnetic materials. We show that one can also determine accurately the saturation magnetization of the sample using ... More
Position of First Doppler PeakJan 04 1999This talk describes an analytic calculation of the position of the first accoustic peak as a function of the matter density and the cosmological constant (work with Y.J. Ng and R. Rohm), agreeing with independent numerical studies. There is also discussion ... More
On Cyclic UniversesDec 09 2006Dark energy in a brane world reconciles an infinitely cyclic cosmology with the second law of thermodynamics. At turnaround one causal patch with no matter and vanishing entropy is retained for the contraction.
Proposal for realization of a Toffoli gate via cavity-assisted collisionJun 09 2003Cavity QED is a versatile tool to explore small scale quantum information processing. Within this setting, we describe a particular protocol for implementing a Toffoli gate with Rydberg atoms and a cavity field. Our scheme uses both resonant and non resonant ... More
Correlations in hypernuclear matterDec 18 2006We investigate short range correlations in nuclear and hypernuclear matter. Self-energies due to short range correlations and their influence on the nucleon and $\Lambda$-hyperon spectral functions are described in an approach accounting for a realistic ... More
Mortality and dust expulsion in early phases of stellar clusters. Evidence from NIR photometry of nearby, spiral galaxiesFeb 25 2013It is often argued that young stellar clusters suffer a significant infant mortality that is partly related to the expulsion of dust and gas in their early phases caused by radiation pressure from hot stars and supernovae. Near-infrared (J-K)-Mk diagrams ... More
Vector Gaussian Multiple Description with Individual and Central ReceiversOct 25 2005L multiple descriptions of a vector Gaussian source for individual and central receivers are investigated. The sum rate of the descriptions with covariance distortion measure constraints, in a positive semidefinite ordering, is exactly characterized. ... More
Some properties of the one-dimensional generalized point interactions (a torso)Oct 19 1999This text is a part of an unfinished project which deals with the generalized point interaction (GPI) in one dimension. We employ two natural parametrizations, which are known but have not attracted much attention, to express the resolvent of the GPI ... More
Self-Similar Collapse in Brans-Dicke Theory and Critical BehaviorMay 03 1996We use the technique of conformal transformations to generate self-similar collapse in Brans-Dicke theory. We analyze the solutions concerning the critical behavior found recently by Choptuik. The critical exponent associated to the formation of black ... More
Open String/Open D-Brane Dualities: Old and NewMar 22 2001May 18 2001We examine magnetic and electric near horizon regions of maximally supersymmetric D-brane and NS5-brane bound states and find transformations between near horizon regions with worldvolume dual magnetic and electric fluxes. These point to dual formulations ... More
The ghost propagator in Coulomb gaugeNov 09 2010We present results for a numerical study of the ghost propagator in Coulomb gauge whereby lattice results for the spatial gluon propagator are used as input to solving the ghost Dyson-Schwinger equation. We show that in order to solve completely, the ... More
Nuclear matter in the crust of neutron starsApr 16 2007The properties of inhomogeneous nuclear matter are investigated considering the self-consistent Skyrme Hartree-Fock approach with inclusion of pairing correlations. For a comparison we also consider a relativistic mean field approach. The inhomogeneous ... More
QCD Dirac Spectra With and Without Random Matrix TheoryJul 03 1998Recent work on the spectrum of the Euclidean Dirac operator spectrum show that the exact microscopic spectral density can be computed in both random matrix theory, and directly from field theory. Exact relations to effective Lagrangians with additional ... More
Dirac Operator Spectra from Finite-Volume Partition FunctionsNov 17 1997Feb 25 1998Based on the relation to random matrix theory, exact expressions for all microscopic spectral correlators of the Dirac operator can be computed from finite-volume partition functions. This is illustrated for the case of $SU(N_c)$ gauge theories with $N_c\geq ... More
Quenched and Unquenched Chiral Perturbation Theory in the ε-RegimeOct 13 2003The chiral limit of finite-volume QCD is the $\epsilon$-regime of the theory. We discuss how this regime can be used for determining low-energy observables of QCD by means of comparisons between lattice simulations and quenched and unquenched chiral perturbation ... More
Non-equilibrium DC noise in a Luttinger liquid with impurityJan 24 1996We compute exactly the non-equilibrium DC noise in a Luttinger liquid with an impurity and an applied voltage. By generalizing Landauer transport theory for Fermi liquids to interacting, integrable systems, we relate this noise to the density fluctuations ... More
N=2 Supersymmetry, Painleve III and Exact Scaling Functions in 2D PolymersApr 29 1992We discuss in this paper various aspects of the off-critical $O(n)$ model in two dimensions. We find the ground-state energy conjectured by Zamolodchikov for the unitary minimal models, and extend the result to some non-unitary minimal cases. We apply ... More