Results for "B. Ascaso"

total 85842took 0.15s
The bright galaxy population of five medium redshift clusters. I. Color-Magnitude Relation, Blue Fractions and Visual MorphologyMay 28 2008May 29 2008Using data of five clusters of galaxies within the redshift range 0.15 $\leq$ z $\leq$ 0.25, imaged with the Nordic Optical Telescope (NOT) in the central $\approx$ 1 Mpc$^2$ in very good seeing conditions, we have performed an exhaustive inspection of ... More
The bright galaxy population of five medium redshift clusters. II. Quantitative Galaxy MorphologyJul 02 2009Aims: Following the study already presented in our previous paper, based on the Nordic Optical Telescope (NOT) sample, which consists of five clusters of galaxies within the redshift range 0.18 $\leq$ z $\leq$ 0.25, imaged in the central 0.5-2 Mpc in ... More
Evolution of BCGs structural parameters in the last $\sim$6 Gyr: feedback processes versus merger eventsJul 19 2010Oct 18 2010We present results on the evolution in the last 6 Gyr of the structural parameters of two samples of brightest cluster galaxies (BCGs). The nearby sample of BCGs consist on 69 galaxies from the WINGS survey spanning a redshift range of 0.04$<$z$<$0.07. ... More
Assessing the reliability of Friends-of-Friends groups on the future Javalambre Physics of the Accelerating Universe Astrophysical SurveyNov 04 2013We have performed a detailed analysis of the ability of the friends-of-friends algorithm in identifying real galaxy systems in deep surveys such as the future Javalambre Physics of the Accelerating Universe Astrophysical Survey. Our approach is two-fold, ... More
Optical Galaxy Clusters in the Deep Lens SurveyJan 13 2014We present the first sample of 882 optically selected galaxy clusters in the Deep Lens Survey (DLS), selected with the Bayesian Cluster Finder. We create mock DLS data to assess completeness and purity rates, and find that both are at least $70\%$ within ... More
I. Apples to apples $A^2$: realistic galaxy simulated catalogs and photometric redshift predictions for next-generation surveysMar 03 2015Aug 31 2015We present new mock catalogues for two of the largest stage-IV next-generation surveys in the optical and infrared: LSST and Euclid, based on an N-body simulation+semi-analytical cone with a posterior modification with \texttt{PhotReal}. This technique ... More
Bayesian Cluster Finder: Clusters in the CFHTLS Archive Research SurveyOct 31 2011The detection of galaxy clusters in present and future surveys enables measuring mass-to-light ratios, clustering properties, galaxy cluster abundances and therefore, constraining cosmological parameters. We present a new technique for detecting galaxy ... More
Next Generation Cosmology: Constraints from the Euclid Galaxy Cluster SurveyMay 08 2015We study the characteristics of the galaxy cluster samples expected from the European Space Agency's Euclid satellite and forecast constraints on cosmological parameters describing a variety of cosmological models. The method used in this paper, based ... More
The Shapes of BCGs and normal Ellipticals in Nearby ClustersJan 15 2010Jan 22 2010We compare the apparent axial ratio distributions of Brightest Cluster Galaxies (BCGs) and normal ellipticals (Es) in our sample of 75 galaxy clusters from the WINGS survey. Most BCGs in our clusters (69%) are classified as cD galaxies. The sample of ... More
II. Apples to apples $A^2$: cluster selection functions for next-generation surveysMay 24 2016Sep 29 2016We present the cluster selection function for three of the largest next-generation stage-IV surveys in the optical and infrared: Euclid-Optimistic, Euclid-Pessimistic and the Large Synoptic Survey Telescope (LSST). To simulate these surveys, we use the ... More
Detecting Galaxy Clusters in the DLS and CARS: a Bayesian Cluster FinderNov 15 2010The detection of galaxy clusters in present and future surveys enables measuring mass-to-light ratios, clustering properties or galaxy cluster abundances and therefore, constraining cosmological parameters. We present a new technique for detecting galaxy ... More
The evolution of Balmer jump selected galaxies in the ALHAMBRA surveyJan 20 2016We present a new color-selection technique, based on the Bruzual & Charlot models convolved with the bands of the ALHAMBRA survey, and the redshifted position of the Balmer jump to select star-forming galaxies in the redshift range 0.5 < z < 1.5. These ... More
The ALHAMBRA survey: tight dependence of the optical mass-to-light ratio on galaxy colour up to z = 1.5May 09 2018Our goal is to characterise the dependence of the optical mass-to-light ratio on galaxy colour up to z = 1.5, expanding the redshift range explored in previous work. From the ALHAMBRA redshifts, stellar masses, and rest-frame luminosities provided by ... More
The ALHAMBRA survey: an empirical estimation of the cosmic variance for merger fraction studies based on close pairsJan 20 2014Our goal is to estimate empirically, for the first time, the cosmic variance that affects merger fraction studies based on close pairs. We compute the merger fraction from photometric redshift close pairs with 10h^-1 kpc <= rp <= 50h^-1 kpc and Dv <= ... More
The ALHAMBRA survey: 2-D analysis of the stellar populations in massive early-type galaxies at z < 0.3Jul 25 2017We present a technique that permits the analysis of stellar population gradients in a relatively low cost way compared to IFU surveys analyzing a vastly larger samples as well as out to larger radii. We developed a technique to analyze unresolved stellar ... More
The impact from survey depth and resolution on the morphological classification of galaxiesJul 21 2015We consistently analyse for the first time the impact of survey depth and spatial resolution on the most used morphological parameters for classifying galaxies through non-parametric methods: Abraham and Conselice-Bershady concentration indices, Gini, ... More
The ALHAMBRA Survey: Bayesian Photometric Redshifts with 23 bands for 3 squared degreesJun 20 2013May 21 2014The ALHAMBRA (Advance Large Homogeneous Area Medium Band Redshift Astronomical) survey has observed 8 different regions of the sky, including sections of the COSMOS, DEEP2, ELAIS, GOODS-N, SDSS and Groth fields using a new photometric system with 20 contiguous ... More
Stellar populations of galaxies in the ALHAMBRA survey up to $z \sim 1$. I. MUFFIT: A Multi-Filter Fitting code for stellar population diagnosticsMay 28 2015We present MUFFIT, a new generic code optimized to retrieve the main stellar population parameters of galaxies in photometric multi-filter surveys, and we check its reliability and feasibility with real galaxy data from the ALHAMBRA survey. Making use ... More
The ALHAMBRA survey: evolution of galaxy spectral segregationJan 14 2016We study the clustering of galaxies as a function of spectral type and redshift in the range $0.35 < z < 1.1$ using data from the Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) survey. The data cover 2.381 deg$^2$ in 7 fields, ... More
The ALHAMBRA survey: Accurate merger fractions by PDF analysis of photometric close pairsSep 03 2014Our goal is to develop and test a novel methodology to compute accurate close pair fractions with photometric redshifts. We improve the current methodologies to estimate the merger fraction f_m from photometric redshifts by (i) using the full probability ... More
An Accurate Cluster Selection Function for the J-PAS Narrow-Band wide-field surveyJan 04 2016The impending Javalambre Physics of the accelerating universe Astrophysical Survey (J-PAS) will be the first wide-field survey of $\gtrsim$ 8500 deg$^2$ to reach the `stage IV' category. Because of the redshift resolution afforded by 54 narrow-band filters, ... More
The ALHAMBRA survey: reliable morphological catalogue of 22,051 early- and late-type galaxiesAug 14 2013ALHAMBRA is a photometric survey designed to trace the cosmic evolution and cosmic variance. It covers a large area of ~ 4 sq. deg in 8 fields, where 7 fields overlap with other surveys, allowing to have complementary data in other wavelengths. All observations ... More
The ALHAMBRA survey: evolution of galaxy clustering since $z \sim 1$Nov 13 2013May 02 2014We study the clustering of galaxies as function of luminosity and redshift in the range $0.35 < z < 1.25$ using data from the Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) survey. The ALHAMBRA data used in this work cover ... More
The ALHAMBRA survey: Discovery of a faint QSO at z = 5.41Jul 19 2013We aim to illustrate the potentiality of the Advanced Large, Homogeneous Area, Medium-Band Redshift Astronomical (ALHAMBRA) survey to investigate the high redshift universe through the detection of quasi stellar objects (QSOs) at redshifts larger than ... More
Intra Cluster Light properties in the CLASH-VLT cluster MACS J1206.2-0847Mar 19 2014We aim at constraining the assembly history of clusters by studying the intra cluster light (ICL) properties, estimating its contribution to the fraction of baryons in stars, f*, and understanding possible systematics/bias using different ICL detection ... More
CLASH: Accurate Photometric Redshifts with 14 HST bands in Massive Galaxy Cluster CoresMay 05 2017Jul 04 2017We present accurate photometric redshifts for galaxies observed by the Cluster Lensing and Supernova survey with Hubble (CLASH). CLASH observed 25 massive galaxy cluster cores with the Hubble Space Telescope in 16 filters spanning 0.2 - 1.7 $\mu$m. Photometry ... More
The ALHAMBRA survey : $B-$band luminosity function of quiescent and star-forming galaxies at $0.2 \leq z < 1$ by PDF analysisNov 28 2016Our goal is to study the evolution of the $B-$band luminosity function (LF) since $z=1$ using ALHAMBRA data. We used the photometric redshift and the $I-$band selection magnitude probability distribution functions (PDFs) of those ALHAMBRA galaxies with ... More
The Violent Youth of Bright and Massive Cluster Galaxies and their Maturation over 7 Billion YearsSep 25 2013May 02 2014In this study we investigate the formation and evolution mechanisms of the brightest cluster galaxies (BCGs) over cosmic time. At high redshift ($z\sim0.9$), we selected BCGs and most massive cluster galaxies (MMCGs) from the Cl1604 supercluster and compared ... More
Low-temperature synthesis of high quality Ni-Fe layered double hydroxides hexagonal plateletsSep 19 2017This paper describes the wet-chemistry synthesis of highly crystalline hexagonal flakes of Ni-Fe layered double hydroxide (LDH) produced at temperature as low as 100 oC. The flakes with diameter in the range of 0.5-1.5 um and the thickness between 15 ... More
High redshift galaxies in the ALHAMBRA survey: II. strengthening the evidence of bright-end excess in UV luminosity functions at 2.5 <= z <= 4.5 by PDF analysisDec 04 2017Feb 28 2018Context. Knowing the exact shape of the UV luminosity function of high-redshift galaxies is important in order to understand the star formation history of the early universe. However, the uncertainties, especially at the faint and bright ends of the LFs, ... More
A $K_s$-band selected catalogue of objects in the ALHAMBRA surveySep 22 2016The original ALHAMBRA catalogue contained over 400,000 galaxies selected using a synthetic F814W image, to the magnitude limit AB(F814W)$\approx$24.5. Given the photometric redshift depth of the ALHAMBRA multiband data (<z>=0.86) and the approximately ... More
The ALHAMBRA survey : Estimation of the clustering signal encoded in the cosmic varianceAug 12 2015The relative cosmic variance ($\sigma_v$) is a fundamental source of uncertainty in pencil-beam surveys and, as a particular case of count-in-cell statistics, can be used to estimate the bias between galaxies and their underlying dark-matter distribution. ... More
J-PLUS: Morphological star/galaxy classification by PDF analysisApr 08 2018Our goal is to morphologically classify the sources identified in the images of the J-PLUS early data release (EDR) into compact (stars) or extended (galaxies) using a suited Bayesian classifier. J-PLUS sources exhibit two distinct populations in the ... More
High redshift galaxies in the ALHAMBRA survey: I. selection method and number counts based on redshift PDFsJan 21 2015Feb 09 2015Context. Most observational results on the high redshift restframe UV-bright galaxies are based on samples pinpointed using the so called dropout technique or Ly-alpha selection. However, the availability of multifilter data allows now replacing the dropout ... More
Euclid preparation III. Galaxy cluster detection in the wide photometric survey, performance and algorithm selectionJun 11 2019Jun 18 2019Galaxy cluster counts in bins of mass and redshift have been shown to be a competitive probe to test cosmological models. This method requires an efficient blind detection of clusters from surveys with a well-known selection function and robust mass estimates. ... More
Galaxy clusters and groups in the ALHAMBRA SurveyJun 11 2015We present a catalogue of 348 galaxy clusters and groups with $0.2<z<1.2$ selected in the 2.78 $deg^2$ ALHAMBRA Survey. The high precision of our photometric redshifts, close to $1\%$, and the wide spread of the seven ALHAMBRA pointings ensure that this ... More
Euclid preparation III. Galaxy cluster detection in the wide photometric survey, performance and algorithm selectionJun 11 2019Galaxy cluster counts in bins of mass and redshift have been shown to be a competitive probe to test cosmological models. This method requires an efficient blind detection of clusters from surveys with a well-known selection function and robust mass estimates. ... More
Euclid preparation III. Galaxy cluster detection in the wide photometric survey, performance and algorithm selectionJun 11 2019Jun 19 2019Galaxy cluster counts in bins of mass and redshift have been shown to be a competitive probe to test cosmological models. This method requires an efficient blind detection of clusters from surveys with a well-known selection function and robust mass estimates. ... More
Avoiding progenitor bias: The structural and mass evolution of Brightest Group and Cluster Galaxies in Hierarchical models since z~1Jan 12 2015Feb 23 2015The mass and structural evolution of massive galaxies is one of the hottest topics in galaxy formation. This is because it may reveal invaluable insights into the still debated evolutionary processes governing the growth and assembly of spheroids. However, ... More
Four-point correlator constraints on electromagnetic chiral parameters and resonance effective LagrangiansMay 21 2004Jun 01 2004We pursue the analysis of a set of generalized DGMLY sum rules for the electromagnetic chiral parameters at order $e^2p^2$ and discuss implications for effective Lagrangians with resonances. We exploit a formalism in which charge spurions are introduced ... More
Electromagnetic corrections in the anomaly sectorMay 21 2002Chiral perturbation theory in the anomaly sector for $N_f=2$ is extended to include dynamical photons, thereby allowing a complete treatment of isospin breaking. A minimal set of independent chiral lagrangian terms is determined and the divergence structure ... More
Breaking and restoring of diffeomorphism symmetry in discrete gravitySep 30 2009We discuss the fate of diffeomorphism symmetry in discrete gravity. Diffeomorphism symmetry is typically broken by the discretization. This has repercussions for the observable content and the canonical formulation of the theory. It might however be possible ... More
Centrality dependence of charged antiparticle to particle ratios near mid-rapidity in d+Au collisions at sqrt(s_NN)=200 GeVSep 17 2003The ratios of the yields of charged antiparticles to particles have been obtained for pions, kaons, and protons near mid-rapidity for d+Au collisions at sqrt(s_NN) = 200 GeV as a function of centrality. The reported values represent the ratio of the yields ... More
Centrality dependence of charged hadron transverse momentum spectra in d+Au collisions at sqrt(s_NN) = 200 GeVJun 18 2003We have measured transverse momentum distributions of charged hadrons produced in d+Au collisions at sqrt(s_NN) = 200 GeV. The spectra were obtained for transverse momenta 0.25 < p_T < 6.0 GeV/c, in a pseudorapidity range of 0.2 < eta < 1.4 in the deuteron ... More
Scaling Variable for Nuclear Shadowing in Deep-Inelastic ScatteringSep 22 1995A new scaling variable is introduced in terms of which nuclear shadowing in deep-inelastic scattering is universal, i.e. independent of $A$, $Q^2$ and $x$. This variable can be interpreted as a measure of the number of gluons probed by the hadronic fluctuations ... More
Type I background fields in terms of type IIB onesApr 16 2008We choose such boundary conditions for open IIB superstring theory which preserve N=1 SUSY. The explicite solution of the boundary conditions yields effective theory which is symmetric under world-sheet parity transformation $\Omega:\sigma\to-\sigma$. ... More
Gauge symmetries decrease the number of Dp-brane dimensionsApr 19 2006Aug 09 2006It is known that the presence of antisymmetric background field $B_{\mu\nu}$ leads to noncommutativity of Dp-brane manifold. Addition of the linear dilaton field in the form $\Phi(x)=\Phi_0+a_\mu x^\mu$, causes the appearance of the commutative Dp-brane ... More
New Multiply-Lensed Galaxies Identified in ACS/NIC3 Observations of Cl0024+1654 Using an Improved Mass ModelFeb 23 2009Sep 22 2009We present an improved strong-lensing analysis of Cl0024+1654 ($z$=0.39) using deep HST/ACS/NIC3 images, based on 33 multiply-lensed images of 11 background galaxies. These are found with a model that assumes mass approximately traces light, with a low ... More
Open strings in relativistic ion trapsFeb 20 2003Apr 04 2003Electromagnetic plane waves provide examples of time-dependent open string backgrounds free of $\alpha'$ corrections. The solvable case of open strings in a quadrupolar wave front, analogous to pp-waves for closed strings, is discussed. In light-cone ... More
Charged Particle Multiplicities in Ultra-relativistic Au+Au and Cu+Cu CollisionsApr 26 2006The PHOBOS collaboration has carried out a systematic study of charged particle multiplicities in Cu+Cu and Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory. A unique feature of the PHOBOS detector is its ... More
The significance of the fragmentation region in ultrarelativistic heavy ion collisionsOct 09 2002We present measurements of the pseudorapidity distribution of primary charged particles produced in Au+Au collisions at three energies, sqrt(s_{NN}) = 19.6, 130, and 200 GeV, for a range of collision centralities. The centrality dependence is shown to ... More
Uniform semiclassical expansions for the direct part of Franck-Condon transitionsOct 13 1997Semiclassical expansions for traces involving Greens functions have two contributions, one from the periodic or recurrent orbits of the classical system and one from the phase space volume, i.e. the paths of infinitesimal length. Quantitative calculations ... More
RF depolarizing resonances in the presence of a full Siberian snake and full snake spin-flippingApr 18 2003Frequent polarization reversals, or spin-flips, of a stored polarized beam in a high energy scattering asymmetry experiments may greatly reduce systematic errors of spin asymmetry measurements. A spin-flipping technique is being developed by using rf ... More
Lower estimates of transition densities and bounds on exponential ergodicity for stochastic PDE'sFeb 18 2004Sep 25 2006A formula for the transition density of a Markov process defined by an infinite-dimensional stochastic equation is given in terms of the Ornstein--Uhlenbeck bridge and a useful lower estimate on the density is provided. As a consequence, uniform exponential ... More
Atomic Vibrations in GlassesAug 22 2019In glasses, atomic disorder combined with atomic connectivity makes understanding of the nature of the vibrations much more complex than in crystals or molecules. With a simple model, however, it is possible to show how disorder generates quasi-local ... More
Continuum Lowering -- A New PerspectiveSep 05 2013Apr 23 2014What is meant by continuum lowering and ionization potential depression (IPD) in a Coulomb system depends upon precisely what question is being asked. It is shown that equilibrium (equation-of-state) phenomena and non-equilibrium dynamical processes like ... More
Gauge symmetries decrease the number of Dp-brane dimensions. II. Inclusion of the Liouville termNov 17 2006Apr 26 2007The presence of the antisymmetric background field $B_{\mu\nu}$ leads to the noncommutativity of the Dp-brane manifold, while the linear dilaton field in the form $\Phi(x)=\Phi_0+a_\mu x^\mu$, causes the appearance of the commutative Dp-brane coordinate, ... More
Inclusive Charmed-Baryon Decays and LifetimesApr 30 1997Jul 11 1997We have quantitatively reanalyzed the inclusive charmed-baryon decays. New ingredients are the Voloshin preasymptotic effects in semileptonic decays and the Cabibbo-subleading contributions to both semileptonic and nonleptonic decays. It has been found ... More
Advantage of the second-order formalism in double space T-dualization of type II superstringJul 08 2019In this article we present bosonic T-dualization in double space of the type II superstring theory in pure spinor formulation. We use the action with constant background fields obtained from the general case under some physically and mathematically justified ... More
A Riemannian approach to low-rank algebraic Riccati equationsDec 17 2013May 28 2014We propose a Riemannian optimization approach for computing low-rank solutions of the algebraic Riccati equation. The scheme alternates between fixed-rank optimization and rank-one updates. The fixed-rank optimization is on the set of fixed-rank symmetric ... More
Power spectrum of electron number density perturbations at cosmological recombination epochDec 12 2008Feb 19 2009The power spectrum of number density perturbations of free electrons is obtained for the epoch of cosmological recombination of hydrogen. It is shown that amplitude of the electron perturbations power spectrum of scales larger than acoustic horizon exceeds ... More
Energy dependence of particle multiplicities in central Au+Au collisionsAug 08 2001We present the first measurement of the pseudorapidity density of primary charged particles in Au+Au collisions at sqrt(s_NN) = 200GeV. For the 6% most central collisions, we obtain dN_ch/deta|_|eta|<1 = 650 +/- 35 (syst). Compared to collisions at sqrt(s_NN) ... More
Transverse Momentum and Rapidity Dependence of HBT Correlations in Au+Au Collisions at sqrt(s_NN) = 62.4 and 200 GeVSep 01 2004Two-particle correlations of identical charged pion pairs from Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV were measured by the PHOBOS experiment at RHIC. Data for the 15% most central events were analyzed with Bertsch-Pratt and Yano-Koonin-Podgoretskii ... More
Dirichlet boundary conditions in type IIB superstring theory and fermionic T-dualityFeb 01 2012Jul 02 2012In this article we investigate the relation between consequences of Dirichlet boundary conditions (momenta noncommutativity and parameters of the effective theory) and background fields of fermionic T-dual theory. We impose Dirichlet boundary conditions ... More
Noncommutativity relations in type IIB theory and their supersymmetryMay 07 2010In the present paper we investigate noncommutativity of $D9$ and $D5$-brane world-volumes embedded in space-time of type IIB superstring theory. Boundary conditions, which preserve half of the initial supersymmetry, are treated as canonical constraints. ... More
Noncommutativity in space-time extended by Liouville fieldNov 28 2007Oct 09 2009The world-sheet quantum conformal invariance can be realized in the presence of the conformal factor $F$, by inclusion of Liouville term. In the background with linear dilaton field, $\Phi(x)=\Phi_0+a_\mu x^\mu$, the field $F$ becomes a new noncommutative ... More
The Magnus property for direct productsMay 05 2016Jun 14 2016A group G is said to have the Magnus property if the following holds: whenever two elements x,y have the same normal closure, then x is conjugate to y or its inverse. We prove: Let p be an odd prime, and let G,H be residually finite-p groups with the ... More
Halpha emission-line stars in molecular clouds III. Canis MajorAug 29 2019A deep objective-prism survey for H-alpha emission stars towards the Canis Major star-forming clouds was performed. A total of 398 Halpha emitters were detected, 353 of which are new detections. There is a strong concentration of these H-alpha emitters ... More
Certain Topics on the Lie Algebra gl(lambda) Representation TheoryMar 15 1997The Lie algebra gl(lambda) dependent on the complex parameter lambda is a continuous version of the Lie algebra gl(inf) of infinite matrices with only finite number of nonzero entries. The gl(lambda) was first introduced by B.L.Feigin in [1] in connection ... More
Consequences of energy conservation in relativistic heavy-ion collisionsAug 15 2005Complete characterization of particle production and emission in relativistic heavy-ion collisions is in general not feasible experimentally. This work demonstrates, however, that the availability of essentially complete pseudorapidity distributions for ... More
Studies of multiplicity in relativistic heavy-ion collisionsNov 08 2004Nov 29 2004In this talk I'll review the present status of charged particle multiplicity measurements from heavy-ion collisions. The characteristic features of multiplicity distributions obtained in Au+Au collisions will be discussed in terms of collision centrality ... More
Pseudorapidity Distribution of Charged Particles in d + Au Collisions at $\sqrt{s_{_{NN}}$ = 200 GeVNov 10 2003The measured pseudorapidity distribution of primary charged particles in minimum-bias d + Au collisions at ${\sqrt{s_{_{NN}}} = \rm {200 GeV}}$ is presented for the first time. This distribution falls off less rapidly in the gold direction as compared ... More
The Radioactive Beam Program at ArgonneJun 06 2006In this talk I will present selected topics of the ongoing radioactive beam program at Argonne and discuss the capabilities of the CARIBU radioactive ion production facility as well as plans for construction of a novel superconducting solenoid spectrometer. ... More
Ratios of charged antiparticles to particles near mid-rapidity in Au+Au collisions at sqrt(s_NN) = 130 GeVApr 18 2001We have measured the ratios of antiparticles to particles for charged pions, kaons and protons near mid-rapidity in central Au+Au collisions at sqrt(s_NN) = 130 GeV. For protons, we observe pbar/p = 0.60 +/- 0.04 (stat.) +/- 0.06 (syst.) in the transverse ... More
Towards a strong-coupling theory of QCD at finite densitySep 02 2002We apply strong-coupling perturbation theory to the QCD lattice Hamiltonian. We begin with naive, nearest-neighbor fermions and subsequently break the doubling symmetry with next-nearest-neighbor terms. The effective Hamiltonian is that of an antiferromagnet ... More
Blandford's Argument: The Strongest Continuous Gravitational Wave SignalApr 18 2008Aug 18 2008For a uniform population of neutron stars whose spin-down is dominated by the emission of gravitational radiation, an old argument of Blandford states that the expected gravitational-wave amplitude of the nearest source is independent of the deformation ... More
A Search for Gamma-Ray Bursts and Pulsars, and the Application of Kalman Filters to Gamma-Ray ReconstructionFeb 04 2002Part I describes the analysis of periodic and transient signals in EGRET data. A method to search for the transient flux from gamma-ray bursts independent of triggers from other gamma-ray instruments is developed. Several known gamma-ray bursts were independently ... More
Time Evolution of the Spread of Diseases with a General Infectivity Profile on a Complex Dynamic NetworkMay 21 2010This manuscript introduces a new analytical approach for studying the time evolution of disease spread on a finite size network. Our methodology can accommodate any disease with a general infectivity profile. This new approach is able to incorporate the ... More
Geometrically thin accretion disk around Maclaurin spheroidNov 22 2014We investigated a semi-analytic and numerical model to study the geometrically thin and optically thick accretion disk around Maclaurin spheroid (MS). The main interest is in the inner region of the so called {\alpha}-disk, {\alpha} being the viscosity ... More
Generalized Dynamic Scaling for Critical Magnetic SystemsMay 22 1997The short-time behaviour of the critical dynamics for magnetic systems is investigated with Monte Carlo methods. Without losing the generality, we consider the relaxation process for the two dimensional Ising and Potts model starting from an initial state ... More
Deterministic Equations of Motion and Phase Ordering DynamicsSep 22 1999We numerically solve microscopic deterministic equations of motion for the 2D $\phi^4$ theory with random initial states. Phase ordering dynamics is investigated. Dynamic scaling is found and it is dominated by a fixed point corresponding to the minimum ... More
On the quantum theory of pure gravitationAug 19 2002A quantum theory of the region of pure gravitation was given earlier in two papers [gr-qc/9908036 (Phys. Lett. A {\bf {265}}, 1 (2000)); gr-qc/0101056]. In this paper I provide further insight into the physics of this region.
Soft asymptotics with mass gapAug 30 2013Dec 05 2013From the operator product expansion the gluon condensate controls a certain power law correction to the ultraviolet behavior of the gauge theory. This is reflected by the asymptotic behavior of the effective gluon mass function as determined by its Schwinger-Dyson ... More
Far from standard Higgs couplingsJun 06 2013In this short note we consider a permitted region in the space of couplings of the 126 GeV boson that extends far away from the standard model Higgs couplings. This region is of interest for more natural models of electroweak symmetry breaking. Stronger ... More
Dynamical symmetry breaking, CP violation, and a Higgs-like particleJan 02 2013Apr 08 2013A pseudoscalar associated with dynamical symmetry breaking can mix with a heavier scalar when CP is violated. We study how such a mixed state that is mostly pseudoscalar can resemble the observed 125 GeV particle. The production rate from $gg$ is enhanced ... More
A pseudoscalar at the LHC: technicolor vs a fourth familyDec 30 2011Mar 06 2012Condensates of colored fermions driving electroweak symmetry breaking could give rise to a light pseudoscalar that would show up in the Higgs search at the LHC. The branching ratios of its decay will distinguish it from the Higgs and illuminate its origin. ... More
Mass gap without vacuum energyJul 01 2009We consider soft nonlocal deformations of massless theories that introduce a mass gap. By use of a renormalization scheme that preserves the ultraviolet softness of the deformation, renormalized quantities of low mass dimension, such as normal mass terms, ... More
The heavy quark search at the LHCMay 14 2007We explore further the discovery potential for heavy quarks at the LHC, with emphasis on the $t'$ and $b'$ of a sequential fourth family associated with electroweak symmetry breaking. We consider QCD multijets, $t\bar{t}+\rm{jets}$, $W+\rm{jets}$ and ... More
t' at the LHC: the physics of discoveryFeb 05 2007Mar 15 2007A search for a fourth family at the LHC is presently a low priority, but we argue that an effective search can be conducted early with only a few inverse femtobarns of data. We discuss a method based on invariant masses of single jets for identifying ... More
From turbulence to financial time seriesSep 11 1997Feb 26 1998We develop a framework especially suited to the autocorrelation properties observed in financial times series, by borrowing from the physical picture of turbulence. The success of our approach as applied to high frequency foreign exchange data is demonstrated ... More
CP Violation from the Neutrino Sector: A Case for the Superweak ModelMay 05 1997Oct 16 1997We discuss how CP violation originating in the right-handed neutrino sector can feed into the quark sector, in an otherwise CP invariant theory. The dominant effects are superweak, and we suggest that this may yield a natural resolution of the strong ... More
Baryon axial currentsNov 19 1998The baryon axial currents are calculated at one-loop order in heavy baryon chiral perturbation theory by employing both a cutoff and dimensional regularization. Data from the semileptonic baryon decays is used to perform a least-squares fit to the two ... More
Photoproduction of eta and eta-prime mesons off nucleons close to thresholdFeb 09 2001The importance of Born terms and resonance exchange for eta and eta-prime photoproduction off both the proton and neutron within U(3) baryon chiral perturbation theory is investigated. Low-lying resonances such as the vector mesons and J^P= 1/2^+, 1/2^- ... More
Numerical simulations on the 4d Heisenberg spin glassOct 17 1994Oct 18 1994We study the 4d Heisenberg spin glass model with Gaussian nearest-neighbor interactions. We use finite size scaling to analyze the data. We find a behavior consistent with a finite temperature spin glass transition. Our estimates for the critical exponents ... More
The Klein-Gordon Equation of a Rotating Charged Hairy Black Hole in (2+1) DimensionsJun 22 2015Nov 22 2015In this paper, we consider the Klein-Gordon equation in a 3D charged rotating hairy black hole background to study behavior of a massive scalar field. In the general case we find periodic-like behavior for the scalar field which may be vanishes at the ... More
Extended Chaplygin Gas in Horava-Lifshitz GravityDec 08 2014Jun 25 2016In this paper, we investigate cosmological models of the extended Chaplygin gas in a universe governed by Horava-Lifshitz gravity. The equation of state for an extended Chaplygin gas is a $(n+2)$-variable equation determined by $A_{n}$, $\alpha$, and ... More
Excitation of oscillation modes by tides in close binaries: constraints on stellar and orbital parametersSep 01 2003The parameter space favourable for the resonant excitation of free oscillation modes by dynamic tides in close binary components is explored using qualitative considerations to estimate the order of magnitude of the tidal force and the frequency range ... More
Polarized deep inelastic scattering at low Bjorken x and resummation of logarithmic corrections, $ln^2(1/x)$Apr 29 2003For an accurate description of the polarized deep inelastic scattering at low $x$ including the logarithmic corrections, $\ln^2(1/x)$, is required. These corrections resummed strongly influence the behaviour of the spin structure functions and their moments. ... More
Recovering corrections in the analysis of intermittent dataMar 22 1999Apr 13 1999The analysis of intermittent data is improved. The standard method of recovering the history of a particle cascade is proved in general not to reproduce the structure of the true cascade. The recovering corrections to the standard method are proposed ... More
Inclusive single particle density in configuration space from the QCD-cascade in DLA approximationMay 30 1997The structure of the QCD gluonic cascade in configuration space is investigated. The explicit form of the inclusive single particle density in configuration space transverse coordinates is derived in the double logarithmic approximation (DLA) of QCD. ... More