308 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- National ObservatoryBR74 papers
- Centro Brasileiro de Pesquisas FísicasBR28 papers
- Universidade de São PauloBR25 papers
- Centre National de la Recherche ScientifiqueFR24 papers
- Universidade Federal do Rio de JaneiroBR22 papers
- Tel Aviv UniversityIL20 papers
- Universidade Federal do Rio Grande do SulBR17 papers
- Petersburg Nuclear Physics InstituteRU16 papers
- European Organization for Nuclear ResearchCH15 papers
- Fundação de Amparo à Pesquisa do Estado de São PauloBR15 papers
- Instituto Superior TécnicoPT15 papers
- University of California, BerkeleyUS15 papers
19 papers · 1 filter
Stationary and static cylindrically symmetric Einstein spaces of the Lewis form
M. A. H. MacCallum, N. O. Santos
The derivation of the general solutions for stationary and static cylindrically symmetric Einstein spaces of Lewis form is revisited and the physical and geometrical meaning of the…
Understanding the Cool DA White Dwarf, G29-38
S. J. Kleinman, R. E. Nather, D. E. Winget +37
The white dwarfs are promising laboratories for the study of cosmochronology and stellar evolution. Through observations of the pulsating white dwarfs, we can measure their interna…
On the role of density inhomogeneity and local anisotropy in the fate of spherical collapse
L. Herrera, A. Di Prisco, J. L. Hernandez-Pastora +1
We obtain an expression for the active gravitational mass of a collapsing fluid distribution, which brings out the role of density inhomogeneity and local anisotropy in the fate of…
The Nature of the Activity in Hickson Compact Groups of Galaxies
Roger Coziol, André L. B. Ribeiro, Reinaldo R. de Carvalho +1
We present the results of the spectral classification of the 82 brightest galaxies in a sample of 17 compact groups. We verify that the AGNs are preferentially located in the most…
Gravitational collapse to toroidal, cylindrical and planar black holes
Jose' P. S. Lemos
Gravitational collapse of non-spherical symmetric matter leads inevitably to non-static external spacetimes. It is shown here that gravitational collapse of matter with toroidal to…
Scalar-QED β-functions near Planck's Scale
Gentil O. Pires
The Renormalization Group Flow Equations of the Scalar-QED model near Planck's scale are computed within the framework of the average effective action. Exact Flow Equations, correc…
Comparison of the SFI Peculiar Velocities with the IRAS 1.2 Jy Gravity Field
Luiz N. da Costa, Adi Nusser, Wolfram Freudling +4
We present a comparison between the peculiar velocity fields measured from the SFI all-sky Sbc-Sc Tully-Fisher catalog and that derived from the \iras 1.2 Jy redshift survey galaxy…
Discovery of a Luminous Quasar in the Nearby Universe
Carlos A. O. Torres, Germano R. Quast, Roger Coziol +4
In the course of the Pico dos Dias survey (PDS), we identified the stellar like object PDS456 at coordinates alpha = 17h 28m 19.796s, delta = -14deg 15' 55.87'' (epoch 2000), with…
The Narrow Line Region of NGC 4151: a Turbulent Cauldron
Claudia Winge, D. J. Axon, F. D. Macchetto +1
We present the first results of the Hubble Space Telescope/Faint Object Camera long-slit spectroscopy of the inner 8" of the Narrow Line Region of NGC 4151 at a spatial resolution…
On the sources of static plane symmetric vacuum space-times
M. F. A. da Silva, Anzhong Wang, N. O. Santos
The static vacuum plane spacetimes are considered, which have two non-trivial solutions: The Taub solution and the Rindler solution. Imposed reflection symmetry, we find that the s…
Geodesics in Lewis Spacetime
L. Herrera, N. O. Santos
The geodesic equations are integrated for the Lewis metric and the effects of the different parameters appearing in the Weyl class on the motion of test particles are brought out.…
Model of the Stochastic Vacuum and QCD Parameters
Erasmo Ferreira, Flávio Pereira
Accounting for the two independent correlation functions of the QCD vacuum, we improve the simple and consistent description given by the model of the stochastic vacuum to the high…
Hadronic sizes and observables in high-energy scattering
Erasmo Ferreira, Flávio Pereira
The functional dependence of the high-energy observables of total cross section and slope parameter on the sizes of the colliding hadrons predicted by the model of the stochastic v…
Evidence of Substructure in the Cluster of Galaxies A3558
Christine C. Dantas, Reinaldo R. de Carvalho, Hugo V. Capelato +1
We investigate the dynamical properties of the cluster of galaxies A3558 (Shapley 8). Studying a region of one square degree ( 3 Mpc) centered on the cluster cD galaxy, w…
Discovery of optical pulsations in V2116 Ophiuchi/GX 1+4
Francisco J. Jablonski, Marildo G. Pereira, Joao Braga +1
We report the detection of pulsations with s period in V2116 Oph, the optical counterpart of the low-mass X-ray binary GX 1+4. The pulsations are sinusoidal with modulat…
Capture of field stars by globular clusters in dense bulge regions
Eduardo Bica, Horacio Dottori, Irapuan Rodrigues de Oliveira F. +2
The recent detection of a double Red Giant Branch in the optical color-magnitude diagram (CMD) of the bulge globular cluster HP1 (Ortolani et al. 1997), a more populated metal-poor…
On a Rapid Lithium Enrichment and Depletion of K Giant Stars
R. de la Reza, N. A. Drake, L. da Silva +2
A model scenario has recently been introduced to explain the presence of very strong Li lines in the spectra of some low mass K giant stars (de la Reza et al. 1996). In this scenar…
The Chemical Evolution of Starburst Nucleus Galaxies
R. Coziol, T. Contini, E. Davoust +1
The metallicities derived from spectroscopic observations of a sample of Starburst Nucleus Galaxies (SBNGs) are compared to those of several other types of galaxies (normal giant g…
Channel Interference in a Quasi Ballistic Aharonov-Bohm Experiment
G. Cernicchiaro, T. Martin, K. Hasselbach +2
New experiments are presented on the transmission of electron waves through a 2DEG (2 dimensional electron gas) ring with a gate on top of one of the branches. Magnetoconductance o…