Results for "S. Maurogordato"

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The Spatial Distribution of Nearby Galaxy Clusters in the Northern and Southern Galactic HemispheresMay 08 1992We compare the spatial distributions of galaxy clusters in the northern and southern galactic hemispheres, and the Abell and ACO clusters distributions. We perform a statistical (correlation and cluster) analysis of a sample of Abell and ACO galaxy clusters ... More
High-Order Correlations of Rich Galaxy ClustersJul 26 1994Jul 28 1994We analyse the two--dimensional all--sky distribution of rich Abell and ACO galaxy clusters by using counts in cells and measuring the high--order area--averaged angular correlation functions. Confirming previous results, we find a well defined hierarchical ... More
Chandra observation of the multiple merger cluster Abell 521Aug 26 2005Sep 15 2005We present the Chandra analysis of the galaxy cluster A521 (z=0.247). The high resolution of the Chandra observation has allowed us to refine the original merging scenario proposed for A521, and to reveal new features in its X-ray emission. A521 has strongly ... More
Galaxy Alignments as a Probe of the Dynamical State of ClustersMay 13 2003We present indications, based on a sample of 303 Abell clusters, for a relation between the dynamical state of clusters and the alignments of galaxy members with their parent cluster major axis orientation as well as with the large scale environment within ... More
Dynamical state and star formation properties of the merging galaxy cluster Abell 3921Sep 03 2004We present the results of a new spectroscopic and photometric survey of the central region of the galaxy cluster A3921 (z=0.094). We detect the presence of two dominant clumps of galaxies: a main cluster centred on the BCG (A3921-A), and a NW sub-cluster ... More
Is the Universe a fractal? Results from the SSRS2Apr 08 1998We perform a fractal analysis of the Southern Sky Redshift Survey 2, following the methods prescribed by Pietronero and collaborators, to check their claim that the galaxy distribution is fractal at all scales, and we discuss and explain the reasons of ... More
The Fundamental Plane of Galaxy ClustersApr 20 1993Velocity dispersion $\sigma$, radius $R$ and luminosity $L$ of elliptical galaxies are known to be related, leaving only two degrees of freedom and defining the so-called ``fundamental plane". In this {\em Letter} we present observational evidence that ... More
Multiple merging events in Abell 521Nov 27 2002We present a detailed spatial and dynamical analysis of the central $\sim$~2.2~\h~Mpc region of the galaxy cluster Abell~521 (z=0.247), based on 238 spectra obtained at the 3.6~m Telescope of ESO and at the CFHT. From the analysis of the 125 galaxies ... More
ATCA observations of the galaxy cluster Abell 3921 - I. Radio emission from the central merging sub-clustersJul 06 2006We present the analysis of our 13 and 22 cm ATCA observations of the central region of the merging galaxy cluster A3921 (z=0.094). We investigated the effects of the major merger between two sub-clusters on the star formation (SF) and radio emission properties ... More
Properties of Very Luminous GalaxiesMar 04 1998Recent analysis of the SSRS2 data based on cell-counts and two-point correlation function has shown that very luminous galaxies are much more strongly clustered than fainter galaxies. In fact, the amplitude of the correlation function of very luminous ... More
Biasing in the Galaxy DistributionMay 20 1996We investigate the variation of galaxy clustering with luminosity using the recently completed SSRS2 sample. Clustering measurements based on the two-point correlation function and the variance of counts in cells reveal the existence of a strong dependence ... More
Five contributions to the 3rd ESO-VLT Workshop ``Galaxy Scaling Relations''Dec 13 1996In the first contribution the basic problems posed by the existence of the Fundamental Plane (FP), and its relations with the Virial Theorem are discussed. Various possibilities are presented that can produce the observed uniform departure from homology ... More
Biasing and high-order statistics from the SSRS2Sep 07 1998We analyze different volume-limited samples extracted from the Southern Sky Redshift Survey (SSRS2), using counts-in-cells to compute the Count Probability Distribution Function (CPDF).From the CPDF we derive volume-averaged correlation functions to fourth ... More
Star formation in the merging galaxy cluster Abell 3921Oct 04 2005Through a combined optical and radio analysis, we have investigated the possible connection between the dynamical state of the merging cluster A3921 and its star formation properties, reaching the conclusion that the on-going merger is triggering a SF ... More
Abell 521: Dynamical analysis of a young clusterMar 31 1999We present the results of a dynamical analysis of the rich X-Ray luminous galaxy cluster Abell 521, and discuss the nature of the arc-like structure first noted by Maurogordato et al. (1996). Our study is based on radial velocities for 41 cluster members, ... More
Galaxy clusters in the CFHTLS. First matched filter candidate catalogue of the Deep fieldsSep 29 2006We apply a matched-filter cluster detection algorithm to the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) i-band data for the Deep-1, Deep-2, Deep-3 and Deep-4 fields covering a total of 4square degrees. To test the implemented procedure we carry ... More
Merging history of three bimodal clustersSep 10 2010We present a combined X-ray and optical analysis of three bimodal galaxy clusters selected as merging candidates at z ~ 0.1. These targets are part of MUSIC (MUlti--Wavelength Sample of Interacting Clusters), which is a general project designed to study ... More
The XXL Survey: XXXVII. The role of the environment in shaping the stellar population properties of galaxies at 0.1<z<0.5Mar 28 2019Exploiting a sample of galaxies drawn from the XXL-N multiwavelength survey, we present an analysis of the stellar population properties of galaxies at 0.1<z<0.5, by studying galaxy fractions and the star formation rate (SFR)-stellar mass(M) relation. ... More
Discovery of Extreme Examples of Superclustering in AquariusJun 25 1999We report the discovery of two highly extended filaments and one extremely high density knot within the region of Aquarius. The supercluster candidates were chosen via percolation analysis of the Abell and ACO catalogs and include only the richest clusters ... More
A2163: Merger events in the hottest Abell galaxy cluster I. Dynamical analysis from optical dataDec 17 2007We present a detailed optical analysis of the galaxy cluster A2163 based on new multicolor wide field imaging and medium-to-high resolution (R~2000) spectroscopy. While X-ray observations have revealed that merging processes are present in this cluster, ... More
A2163: Merger events in the hottest Abell galaxy cluster II. Subcluster accretion with galaxy-gas separationNov 13 2010Located at z = 0.203, A2163 is a rich galaxy cluster with an intra-cluster medium (ICM) that exhibits extraordinary properties, including an exceptionally high X-ray luminosity, average temperature, and a powerful and extended radio halo. The irregular ... More
The XMM-LSS survey: the Class 1 cluster sample over the extended 11 deg$^2$ and its spatial distributionAug 27 2014This paper presents 52 X-ray bright galaxy clusters selected within the 11 deg$^2$ XMM-LSS survey. 51 of them have spectroscopic redshifts ($0.05<z<1.06$), one is identified at $z_{\rm phot}=1.9$, and all together make the high-purity "Class 1" (C1) cluster ... More
The XXL Survey VIII: MUSE characterisation of intracluster light in a z$\sim$0.53 cluster of galaxiesJan 04 2016Within a cluster, gravitational effects can lead to the removal of stars from their parent galaxies. Gas hydrodynamical effects can additionally strip gas and dust from galaxies. The properties of the ICL can therefore help constrain the physical processes ... More
The XXL Survey VII: A supercluster of galaxies at z=0.43Dec 14 2015The XXL Survey is the largest homogeneous and contiguous survey carried out with XMM-Newton. Covering an area of 50 square degrees distributed over two fields, it primarily investigates the large-scale structures of the Universe using the distribution ... More
The XXL Survey XXVIII. Galaxy luminosity functions of the XXL-N clustersJul 09 2018Jul 10 2018The main goal of this study is to investigate the LF of a sample of 142 X-ray selected clusters, with spectroscopic redshift confirmation and a well defined selection function, spanning a wide redshift and mass range, and to test the LF dependence on ... More
The ESO Slice Project (ESP) galaxy redshift survey: I. Description and First ResultsApr 11 1997The ESO Slice Project (ESP) is a galaxy redshift survey we have recently completed as an ESO Key-Project. The ESP covers 23.3 square degrees in a region close to the South Galactic Pole. The survey is nearly complete (85%) to the limiting magnitude b_J=19.4 ... 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
Distant galaxy clusters in the XMM Large Scale Structure surveyDec 17 2012(Abridged) Distant galaxy clusters provide important tests of the growth of large scale structure in addition to highlighting the process of galaxy evolution in a consistently defined environment at large look back time. We present a sample of 22 distant ... More
The ESO Slice Project (ESP) galaxy redshift survey: II. The luminosity function and mean galaxy densityMay 13 1997(Abridged) The ESO Slice Project (ESP) is a galaxy redshift survey we have completed as an ESO Key-Project over ~23 square degrees, in a region near the South Galactic Pole. The survey is nearly complete to the limiting magnitude b_J=19.4 and consists ... More
Subaru weak-lensing study of A2163: bimodal mass structureJun 30 2011Sep 17 2011We present a weak-lensing analysis of the merging cluster A2163 using Subaru/Suprime-Cam and CFHT/Mega-Cam data and discuss the dynamics of this cluster merger, based on complementary weak-lensing, X-ray, and optical spectroscopic datasets. From two dimensional ... More
Nature and Environment of Very Luminous GalaxiesJun 18 2003The most luminous galaxies in the blue passband have a larger correlation amplitude than L* galaxies. They do not appear to be preferentially located in rich clusters or groups, but a significant fraction of them seem to be in systems which include fainter ... More
Evolution of the real-space correlation function from next generation cluster surveysDec 08 2016Jan 13 2017We investigate to which accuracy it is possible to recover the real-space two-point correlation function of galaxy clusters from cluster catalogues based on photometric redshifts, and test our ability to measure the redshift and mass evolution of the ... More
The XXL Survey XXV. Cosmological analysis of the C1 cluster number countsOct 03 2018Context. We present an estimation of cosmological parameters with clusters of galaxies. Aims. We constrain the $\Omega_m$, $\sigma_8$, and $w$ parameters from a stand-alone sample of X-ray clusters detected in the 50 deg$^2$ XMM-XXL survey with a well-defined ... More
Galaxy cluster searches based on photometric redshifts in the four CFHTLS Wide fieldsSep 05 2011Sep 12 2011We have developed a method for detecting clusters in large imaging surveys, based on the detection of structures in galaxy density maps made in slices of photometric redshifts. This method was first applied to the Canada France Hawaii Telescope Legacy ... More
The ESO Slice Project (ESP) galaxy redshift survey IV. A discussion of systematic biases in galaxy redshift determinationsMay 19 1998We present a detailed discussion of the redshift errors associated to the ESO Slice Project measurements. For a subsample of 742 galaxies with redshifts determined both from the absorption lines (V_{abs}) and from the emission lines (V_{emi}), we find ... More
Preliminary Results from the ESO Slice Project (ESP)Sep 28 1994We present the first results of a galaxy redshift survey, ESO Slice Project (ESP), we are accomplishing as an ESO Key-Project over about 30 square degrees in a region near the South Galactic Pole. The limiting magnitude is b_J = 19.4. Observations have ... More
The ESO Slice Project [ESP] galaxy redshift survey: V. Evidence for a D=3 sample dimensionalityMar 03 1998Mar 05 1998The issue of the approximate isotropy and homogeneity of the observable universe is one of the major topics in modern Cosmology: the common use of the Friedmann-Robertson-Walker [FWR] metric relies on these assumptions. Therefore, results conflicting ... More
The ESO Slice Project (ESP) galaxy redshift survey: VI Groups of GalaxiesNov 10 1998In this paper we identify objectively and analyze groups of galaxies in the recently completed ESP survey. We find 231 groups above the number overdensity threshold delta(rho)/rho=80 in the redshift range 5000<cz <60000 km/s. These groups contain 1250 ... More
The XXL Survey: XVI. The clustering of X-ray selected galaxy clusters at z~0.3Jul 12 2018Galaxy clusters trace the highest density peaks in the large-scale structure of the Universe. Their clustering provides a powerful probe that can be exploited in combination with cluster mass measurements to strengthen the cosmological constraints provided ... More
The ESO Slice Project (ESP) Galaxy Redshift Survey. VII. The Redshift and Real-Space Correlation FunctionsJan 27 1999We present analyses of the two-point correlation properties of the ESP galaxy redshift survey. From the redshift-space correlation function xi(s), we see positive clustering out to separations ~50/h Mpc, with a smooth break on larger scales and zero-crossing ... More
The mass profile and dynamical status of the z~0.8 galaxy cluster LCDCS 0504Mar 14 2014Constraints on the mass distribution in high-redshift clusters of galaxies are not currently very strong. We aim to constrain the mass profile, M(r), and dynamical status of the $z \sim 0.8$ LCDCS 0504 cluster of galaxies characterized by prominent giant ... More
Preliminary Results from the ESO Slice Project (ESP)Dec 14 1993We present the first results of a galaxy redshift survey, ESO Slice Project (ESP), we are accomplishing as an ESO Key--Project over about 40 square degrees in a region near the South Galactic Pole. The limiting magnitude is $b_J = 19.4$. Up to now $\sim ... More
The ESO Slice Project (ESP) galaxy redshift survey: III. The SampleMay 14 1998The ESO Slice Project (ESP) is a galaxy redshift survey extending over about 23 square degrees, in a region near the South Galactic Pole. The survey is ~85% complete to the limiting magnitude b_J=19.4 and consists of 3342 galaxies with redshift determination. ... More
Galaxy cluster searches by photometric redshifts in the CFHTLSOct 20 2009In order to enlarge publicly available optical cluster catalogs, in particular at high redshift, we have performed a systematic search for clusters of galaxies in the CFHTLS. We used the Le Phare photometric redshifts for the galaxies detected with magnitude ... More
The XXL Survey: XXIII. The Mass Scale of XXL Clusters from Ensemble SpectroscopyNov 19 2017An X-ray survey with the XMM-Newton telescope, XMM-XXL, has identified hundreds of galaxy groups and clusters in two 25 deg$^2$ fields. Combining spectroscopic and X-ray observations in one field, we determine how the kinetic energy of galaxies scales ... More
The XXL Survey: VI. The 1000 brightest X-ray point sourcesMar 10 2016X-ray extragalactic surveys are ideal laboratories for the study of the evolution and clustering of active galactic nuclei (AGN). The XXL Survey spans two fields of a combined 50 $deg^2$ observed for more than 6Ms with XMM-Newton, occupying the parameter ... More
The XXL Survey: XXVII. The 3XLSS point source catalogueOct 09 2018We present the version of the point source catalogue of the XXL Survey that was used, in part, in the first series of XXL papers. In this paper we release, in our database in Milan and at CDS: (i) the X-ray source catalogue with 26056 objects in two areas ... More
The XXL Survey: XXX. Characterisation of the XLSSsC N01 supercluster and analysis of the galaxy stellar populationsMay 10 2018Superclusters form from the largest enhancements in the primordial density perturbation field and extend for tens of Mpc, tracing the large-scale structure of the Universe. We characterise XLSSsCN01, a rich supercluster at z~0.3 detected in the XXL Survey, ... More
Abell 2384: the galaxy population of a cluster post-mergerAug 04 2014Sep 01 2014We combine multi-object spectroscopy from the 2dF and EFOSC2 spectrographs with optical imaging of the inner 30'x30' of A2384 taken with the ESO Wide Field Imager. We carry out a kinematical analysis using the EMMIX algorithm and biweight statistics. ... More
The XXL Survey: XXII. The XXL-North spectrophotometric sample and galaxy stellar mass function in X-ray detected groups and clustersOct 12 2017The fraction of galaxies bound in groups in the nearby Universe is high (50% at z~0). Systematic studies of galaxy properties in groups are important in order to improve our understanding of the evolution of galaxies and of the physical phenomena occurring ... More
Mapping the kinetic Sunyaev-Zel'dovich effect toward MACS J0717.5+3745 with NIKAJun 24 2016Measurement of the gas velocity distribution in galaxy clusters provides insight into the physics of mergers, through which large scale structures form in the Universe. Velocity estimates within the intracluster medium (ICM) can be obtained via the Sunyaev-Zel'dovich ... More
Sub-structure and merger detection in resolved NIKA Sunyaev-Zel'dovich images of distant clustersDec 05 2017Sub-structures in the hot gas of galaxy clusters are related to their formation history and to the astrophysical processes at play in the intracluster medium (ICM). The thermal Sunyaev-Zel'dovich (tSZ) effect is directly sensitive to the line-of-sight ... More
Mapping the hot gas temperature in galaxy clusters using X-ray and Sunyaev-Zel'dovich imagingJun 30 2017Jul 21 2017We propose a method to map the temperature distribution of the hot gas in galaxy clusters that uses resolved images of the thermal Sunyaev-Zel'dovich (tSZ) effect in combination with X-ray data. Application to images from the New IRAM KIDs Array (NIKA) ... More
Mapping the kinetic Sunyaev-Zel'dovich effect toward MACS J0717.5+3745 with NIKAJun 24 2016Dec 08 2016Measurement of the gas velocity distribution in galaxy clusters provides insight into the physics of mergers, through which large scale structures form in the Universe. Velocity estimates within the intracluster medium (ICM) can be obtained via the Sunyaev-Zel'dovich ... More
The galaxy population of the complex cluster system Abell 3921May 21 2013Jul 09 2014We present a spectrophotometric analysis of the galaxy pop. in the area of the merging cluster Abell 3921 at redshift 0.093. We investigate the impact of the complex cluster environment on galaxy properties such as morphology or star formation rate. We ... More
The XXL Survey. II. The bright cluster sample: catalogue and luminosity functionDec 14 2015Context. The XXL Survey is the largest survey carried out by the XMM-Newton satellite and covers a total area of 50 square degrees distributed over two fields. It primarily aims at investigating the large-scale structures of the Universe using the distribution ... 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
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
The XXL Survey XX: The 365 cluster catalogueOct 09 2018In the currently debated context of using clusters of galaxies as cosmological probes, the need for well-defined cluster samples is critical. The XXL Survey has been specifically designed to provide a well characterised sample of some 500 X-ray detected ... More
Galaxy clusters in the SDSS Stripe 82 based on galaxy photometric redshiftsApr 02 2015Apr 13 2015Based on a recent photometric redshift galaxy catalogue, we have searched for galaxy clusters in the Stripe~82 region of the Sloan Digital Sky Survey by applying the Adami & MAzure Cluster FInder (AMACFI). Extensive tests were made to fine-tune the AMACFI ... More
The XXL Survey: I. Scientific motivations - XMM-Newton observing plan - Follow-up observations and simulation programmeDec 14 2015We present the XXL Survey, the largest XMM programme totaling some 6.9 Ms to date and involving an international consortium of roughly 100 members. The XXL Survey covers two extragalactic areas of 25 deg2 each at a point-source sensitivity of ~ 5E-15 ... More
The XXL survey: first results and futureOct 06 2016Jul 11 2017The XXL survey currently covers two 25 sq. deg. patches with XMM observations of ~10ks. We summarise the scientific results associated with the first release of the XXL data set, that occurred mid 2016. We review several arguments for increasing the survey ... More
The XXL survey: first results and futureOct 06 2016The XXL survey currently covers two 25 sq. deg. patches with XMM observations of ~10ks. We summarise the scientific results associated with the first release of the XXL data set, that occurred mid 2016. We review several arguments for increasing the survey ... More
Band insulator to Mott insulator transition in a bilayer Hubbard modelMar 27 2007The ground state phase diagram of the half-filled repulsive Hubbard model in a bilayer is investigated using cluster dynamical mean field theory. For weak to intermediate values of Coulomb repulsion $U$, the system undergoes a transition from a Mott insulating ... More
On the Ascoli property for locally convex spaces and topological groupsNov 09 2016Nov 14 2016We characterize Ascoli spaces by showing that a Tychonoff space $X$ is Ascoli iff the canonical map from the free locally convex space $L(X)$ over $X$ into $C_k\big( C_k(X)\big)$ is an embedding of locally convex spaces. We prove that an uncountable direct ... More
Metric-affine $f(R)$-gravity with torsion: an overviewOct 27 2009Torsion and curvature could play a fundamental role in explaining cosmological dynamics. f(R)-gravity with torsion is an approach aimed to encompass in a comprehensive scheme all the Dark Side of the Universe (Dark Energy and Dark Matter). We discuss ... More
Groups of quasi-invariance and the Pontryagin dualityDec 09 2008Oct 01 2009A Polish group $G$ is called a group of quasi-invariance or a QI-group, if there exist a locally compact group $X$ and a probability measure $\mu$ on $X$ such that 1) there exists a continuous monomorphism of $G$ to $X$, and 2) for each $g\in X$ either ... More
The Higgs Boson Production Cross Section as a Precision Observable?Mar 06 2002Jul 30 2002We investigate what can be learned at a linear collider about the sector of electroweak symmetry breaking from a precise measurement of the Higgs boson production cross section through the process e+e- -> hZ. We focus on deviations from the Standard Model ... More
X-ray observations of cluster outskirts: current status and future prospectsMay 03 2010Dec 22 2010Past and current X-ray mission allow us to observe only a fraction of the volume occupied by the ICM. After reviewing the state of the art of cluster outskirts observations we discuss some important constraints that should be met when designing an experiment ... More
Lower and upper bounds on the mass of light quark-antiquark scalar resonance in the SVZ sum rulesMay 23 2016The calculation of the mass of light scalar isosinglet meson within the Shifman--Vainshtein--Zakharov (SVZ) sum rules is revisited. We develop simple analytical methods for estimation of hadron masses in the SVZ approach and try to reveal the origin of ... More
Low-energy holographic models for QCDFeb 01 2011Apr 09 2011We consider the bottom-up holographic models for QCD which contain the ultraviolet (UV) cutoff. Such models are supposed to describe exclusively the low-energy sector of QCD. The introduction of UV cutoff in the soft wall model is shown to result in a ... More
AdS/QCD models describing a finite number of excited mesons with Regge spectrumMar 02 2009The typical AdS/QCD models deal with the large-N_c limit of QCD, as a consequence the meson spectrum consists of the infinite number of states that is far from the real situation. Basing on introduction of anharmonic corrections to the holographic potential, ... More
Generalized Soft Wall ModelOct 18 2012Jan 27 2013We develop an exactly solvable generalization of the soft wall holographic model for the vector mesons. The generalization preserves the ultraviolet and infrared asymptotics of the soft wall model and contains an additional free parameter. This new parameter ... More
Comment on "Parity Doubling and SU(2)_L X SU(2)_R Restoration in the Hadronic Spectrum" and "Parity Doubling Among the Baryons"May 09 2006Some aspects of two recent papers on parity doubling in the hadronic spectrum and its relation to restoration of linearly realized chiral symmetry are critically discussed.
Steenrod operations and the diagonal morphismJul 04 2013Jan 15 2014We show how to find the Steenrod operations in H^*(X) (the coefficients in F_p) given the diagonal morphism d_#:S_*(X)->S_*(X^p) and the action of the cyclic group C_p on S_*(X^p). Our construction needs no other data such as Eilenberg-Zilber morphisms. ... More
The Game of Cipher BeadsMay 20 2009Jul 29 2009Comparison between the various impact factors of a few Russian journals demonstrates the deficiencies of the popular citation indices.
On Grothendieck SubspacesApr 04 2005The modulus of an order bounded functional on a Riesz space is the sum of a pair of Riesz homomorphisms if and only if the kernel of this functional is a Grothendieck subspace of the ambient Riesz space. An operator version of this fact is given.
Generalized Integral Siding Mode Manifold Design: A Sum of Squares ApproachMar 30 2015May 21 2015This paper presents a general form of integral sliding mode manifold, and proposes an algorithmic approach based on Sum of Squares (SOS) programming to design generalized integral sliding mode manifold and controller for nonlinear systems with both matched ... More
Effective Use of Human Computer Interaction in Digital Academic Supportive DevicesJan 03 2015In this research, a literature in human-computer interaction is reviewed and the technology aspect of human computer interaction related with digital academic supportive devices is also analyzed. According to all these concerns, recommendations to design ... More
Influence of Facebook in Academic Performance of Sri Lankan University StudentsJan 03 2015Facebook is only an electronic communication between human but unfortunately it has become an addiction for all. This paper examines the usage of Facebook among university students and its influence in their academic performance. The impact of Facebook ... More
Di-photon Higgs signals at the LHC in the Next-to-Minimal Supersymmetric Standard ModelMar 10 2006The NMSSM contains a Higgs singlet in addition to the two Higgs doublets typical of the MSSM, thus resulting in a total of seven physical Higgs mass states. Therefore, the phenomenology of the NMSSM Higgs sector can vary considerably from that of the ... More
Shock Dissipation in Magnetically Dominated Impulsive FlowsJan 17 2012We have revisited the issue of shock dissipation and emission and its implications for the internal shock model of the prompt GRB emission and studied it in the context of impulsive Poynting-dominated flows. Our results show that unless the magnetization ... More
3+1 MagnetodynamicsAug 17 2011Aug 30 2011The Magnetodynamics, or Force-Free Degenerate Electrodynamics, is recognized as a very useful approximation in studies of magnetospheres of relativistic stars. In this paper we discuss various forms of Magnetodynamic equations which can be used to study ... More
Blandford-Znajek mechanism versus Penrose processApr 11 2008During the three decades since its theoretical discovery the Blandford-Znajek process of extracting the rotational energy of black holes has become one of the foundation stones in the building of modern relativistic astrophysics. However, it is also true ... More
Multi-dimensional Numerical Scheme for Resistive Relativistic MHDAug 02 2007The paper describes a new upwind conservative numerical scheme for special relativistic resistive magnetohydrodynamics with scalar resistivity. The magnetic field is kept approximately divergence free and the divergence of the electric field consistent ... More
Geometry of N=4, d=1 nonlinear supermultipletNov 09 2006We construct the general action for $N=4, d=1$ nonlinear supermultiplet including the most general interaction terms which depend on the arbitrary function $h$ obeying the Laplace equation on $S^3$. We find the bosonic field $B$ which depends on the components ... More
Random walks in a random environmentMar 05 2005Random walks as well as diffusions in random media are considered. Methods are developed that allow one to establish large deviation results for both the `quenched' and the `averaged' case.
Heavy charged Higgs boson production at next generation $γγ$ collidersNov 05 2002We investigate the scope of all relevant production modes of charged Higgs bosons in the MSSM, with mass larger than the one of the top quark, at future Linear Colliders operating in $\gamma\gamma$ mode at the TeV energy scale. Final states with one or ... More
Electron-hole asymmetry in magnetic properties of lightly doped high-$T_{\rm C}$ superconductors: a quantum Monte Carlo studyAug 14 2003Using a recently developed variational quantum Monte Carlo method, magnetic properties of high-$T_{\rm C}$ superconductors are studied at zero temperature ($T$), by numerical simulations on the 2D t-J model. Our focus here is to explore the difference ... More
Reducing Polarization Mode Dispersion With Controlled Polarization RotationsJun 02 2006One of the fundamental limitations to high bit rate, long distance, telecommunication in optical fibers is Polarization Mode Dispersion (PMD). Here we introduce a conceptually new method to reduce PMD in optical fibers by carrying out controlled rotations ... More
Superconducting networks with the proximity effectNov 06 2009May 20 2011We report on the first observation of a novel type of superconducting proximity network using a superconductor-normal metal bilayer. Little-Parks oscillation measurements show that the superconducting current flows through a path enclosed by the edge ... More
An Observational Perspective of the IMF: Progress and ChallengesOct 20 2015The stellar initial mass function (IMF) is a fundamental astrophysical quantity that impacts a wide range of astrophysical problems from heavy element distribution to galactic evolution to planetary system formation. However, the origin and universality ... More
The mass function of young star clusters in spiral galaxiesDec 07 2008Sep 23 2009The initial cluster mass function (ICMF) in spiral galaxy discs is constrained and compared with data for old globular clusters and young clusters in starbursts. It is found that the observed ages and luminosities of the brightest clusters in spiral discs ... More
Observational Constraints on Cluster EvolutionSep 04 2006Current observational constraints on the dynamical evolution of star clusters are reviewed. Theory and observations now agree nicely on the mass dependency and time scales for disruption of young star clusters in galactic disks, but many problems still ... More
Zero-Range Potentials in Multi-Channel Diatomic Molecule ScatteringMay 17 2002The method of zero-range potentials is generalized to account for the molecular electron excitation process. It is made by a matrix formulation in which a state vector components are associated with a scattering channel. The multi-center target is considered ... More
Finite-size effects on the Hamiltonian dynamics of the XY-modelMay 31 2001The dynamical properties of the finite-size magnetization M in the critical region T<T_{KTB} of the planar rotor model on a L x L square lattice are analyzed by means of microcanonical simulations . The behavior of the q=0 structure factor at high frequencies ... More
Light-front $φ^4_{1+1}$ theory using a many-boson symmetric-polynomial basisDec 29 2015We extend earlier work on fully symmetric polynomials for three-boson wave functions to arbitrarily many bosons and apply these to a light-front analysis of the low-mass eigenstates of $\phi^4$ theory in 1+1 dimensions. The basis-function approach allows ... More
Application of a light-front coupled-cluster method to quantum electrodynamicsJun 26 2012A field-theoretic formulation of the exponential-operator technique is applied to a Hamiltonian eigenvalue problem in electrodynamics, quantized in light-front coordinates. Specifically, we consider the dressed-electron state, without positron contributions ... More
Magnetization induced by odd-frequency spin-triplet Cooper pairs in a Josephson junction with metallic trilayersJul 14 2015We theoretically study the magnetization inside a normal metal induced in an s-wave superconductor/ferromagnetic metal/normal metal/ferromagnetic metal/s-wave superconductor (S/F1/N/F2/S) Josephson junction. Using quasiclassical Green's function method, ... More