I. F. Mirabel
(CEA-Saclay, France and CONICET, Argentina)
04/05/2013, 09:30
STARS2013
Talk
The 'final frontier' in studies of cosmic structure formation is the epoch of cosmic reionization, when the cold neutral Intergalactic Medium (IGM) was heated and reionized by primordial galaxies, a few hundred million years after the Big Bang. I propose that a large fraction of the first generations of massive stars in primordial galaxies ended as black holes and neutron stars in High Mass...
César A. Z. Vasconcellos
(Instituto de Física, Universidade Federal do Rio Grande do Sul, Brazil)
04/05/2013, 10:15
STARS2013
Talk
Nuclear science has developed many excellent descriptions that embody various properties of the nucleus, and nuclear matter at low, medium and high densities. However, a full microscopic understanding of nuclear systems is still lacking. The aim of our theoretical research group is to shed some light on such challenges and particularly on open questions facing the high density nuclear...
Marcus Bleicher
(Frankfurt Institute for Advanced Studies and Goethe Universität, Frankfurt am Main, Germany)
04/05/2013, 11:15
We review the main ideas behind the predictions of mini black holes for the LHC. These ideas come into discussion about 15 years ago together with the idea of a reduced Planck scale, known as TeV gravity. A main ingredient of these Models, namely the ADD model and the RS model was the idea of additional space-like dimensions which would lead to a dissolution of the gravitational interactions...
Alejandro Cabo Montes de Oca
(Departamento de Física Teórica, ICIMAF, La Habana, Cuba)
04/05/2013, 12:00
STARS2013
Talk
The form of the resulting Feynman propagators in the recently proposed local and gauge invariant QCD for massive fermions, suggests the existence of indefinite metric associated to quark states, a property that might relate it with the known Lee-Wick theories. Thus, the nature of the asymptotic free quark states in the theory is investigated here. For this purpose the quadratic part of the...
Olivier Piguet
(Universidade Federal de Viçosa, Brazil)
04/05/2013, 14:00
STARS2013
Talk
The purpose of this talk is to give a short general introduction to Loop Quantum Gravity (LQG), beginning with some motivations for quantizing General Relativity, listing various attempts and then focusing on the case of LQG.
Thomas Boller
(Max-Planck-Institute for extraterrestrial physics, Garching, Germany)
04/05/2013, 14:30
STARS2013
Talk
Gravitation is very well described by Einstein’s General Gelativity. However, several theoretical predictions like the existence of curvature singularities and event horizons are under debate. This motivated to modify the standard theory of gravity. Here, we contrast predictions made by General Relativity with the pseudo–complex field theory proposed recently. Among them we study the...
Martin Roth
(Leibniz Institut für Astrophysik Potsdam, Germany)
04/05/2013, 15:15
STARS2013
Talk
The discovery of dark energy as a mysterious force that is accelerating the expansion of the universe has become one of the most exciting problems of modern astrophysics. Not coincidentally, the Nobel Price for Physics in 2011 was awarded to Saul Perlmutter, Brian P. Schmidt, and Adam G. Riess, whose work on distant supernova distance determinations eventually lead to this discovery. Yet the...
Nelson Pinto-Neto
(Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro, Brazil)
04/05/2013, 16:15
STARS2013
Talk
After making a review on the possible scenarios for the early Universe, I will make a critical comparison among viable inflationary and bouncing models for the primordial Universe which I will describe, and discuss how the usual problems of the standard cosmological model are addressed by them in order to investigate if they can be distinguished by future observations.
Roberto Sussman
(Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México (ICN-UNAM), Mexico D.F., Mexico)
04/05/2013, 16:45
STARS2013
Talk
Averaging the fully tensorial Einstein equations and their solutions (spacetimes) is an open problem in General Relativity. I present and discuss the proper 3-volume scalar averaging formalism endowed with a non-trivial weight factor, and its application to inhomogeneous cosmologies (LTB and Szekeres models). This formalism leads to a fully determined system of evolution equations for the...
Mirko Schäfer
(FIAS, University of Frankfurt am Main, Germany)
04/05/2013, 17:15
STARS2013
Talk
The coordinates of standard General Relativity are extended to pseudo-complex variables. In the eight dimension space the geometric differential structure is investigated. Mapping to the physical subspace with real coordinates leaves a remnant of the pseudo-complex structure, which adds terms to the Lagrangian. The Einstein equations are modified, adding the contributions of an energy-momentum...
Elena Bratkovskaya
(ITP and FIAS, Uni. Frankfurt, Germany)
05/05/2013, 09:30
STARS2013
Talk
The dynamics of partons and hadrons in relativistic nucleus-nucleus collisions is analyzed within the novel Parton-Hadron-String Dynamics (PHSD) transport approach, which is based on a dynamical quasiparticle model for partonic phase (DQPM) including a dynamical hadronization scheme. The PHSD model reproduces a large variety of observables from SPS to LHC energies, e.g. as quark-number...
José Halim Montes de Oca
(Universidad Nacional Autónoma de México, Mexico D.F., Mexico)
05/05/2013, 10:15
STARS2013
Talk
We discuss the formulation of the general two-Higgs doublet model type III, which incorporates flavor changing neutral scalar interactions (FCNSI) and CP violation from several sources. FCNSI and CP violation can arise from Yukawa terms meanwhile Higgs potential can contribute as source of explicit or spontaneous CP violation. We discuss the case that includes CP violation with Yukawa...
Joerg Aichelin
(SUBATECH, University of Nantes)
05/05/2013, 11:15
STARS2013
Talk
To understand the centrality dependence of measured observables, like the multiplicity < pt^2 > and the elliptic flow of identified particles at midrapidity as well as the elliptic flow of charges hadrons, has been a challenge for theory since many years. Although the multiplicity of different particles in central collisions corresponds exactly to the expectation for a completely thermalized...
Shuang-Nan Zhang
(Institute of High Energy Physics, Beijing, China)
05/05/2013, 12:00
STARS2013
Talk
The possibility that we are living in an expanding underdensed region has made many to debate if dark energy is needed to explain the apparent over-dimming of distant Type Ia supernovae (SNe Ia). In this report, we first show that the currently best measured local Hubble constant is larger than the cosmological Hubble constant, i.e., our local universe is expanding faster than the distant...
German Lugones
(Federal University of ABC, Santo André, Brazil)
05/05/2013, 14:00
STARS2013
Talk
We study the evolution of turbulence in the early universe at the QCD epoch using a state-of-the-art equation of state derived from lattice QCD simulations. Since the transition is a crossover we assume that temperature and velocity fluctuations were generated by some event in the previous history of the Universe and survive until the QCD epoch due to the extremely large Reynolds number of the...
Carola Dobrigkeit
(Universidade Estadual de Campinas, Brazil)
05/05/2013, 14:30
STARS2013
Talk
The main goal of the Pierre Auger Observatory is to study cosmic rays with energies above 1 EeV with unprecedented statistics and learn about the origin and nature of these extremely energetic particles. We will review the latest results obtained by the Auger Observatory concerning the energy spectrum, arrival directions, mass composition and flux limits of non-charged particles and further...
Elizabeth Rodriguez Querts
(Instituto de Cibernética, Matemática y Física (ICIMAF), La Habana, Cuba)
05/05/2013, 15:15
STARS2013
Talk
We address the problem of gauge-Higgs unification in a Randall-Sundrum I space, extended with one compact dimension, by considering that the 4D Higgs boson is a part of the extra dimensional components of the gauge fields.
Hugo Perez Rojas
(Instituto de Cibernética, Matemática y Física (ICIMAF), La Habana, Cuba)
05/05/2013, 16:15
STARS2013
Talk
We discuss the effect of a strong magnetic field in the behavior of the symmetry of an electrically neutral electroweak plasma. We analyze the case of a strong magnetic field and low temperatures as compared with the W rest energy. If the magnetic field is large enough, it is self-consistently maintained. Charged vector bosons play the most important role, leading only to a decrease of the...
Christian Motch
(Observatoire Astronomique de Strasbourg, France)
06/05/2013, 09:30
STARS2013
Talk
The extremely high X-ray luminosity of non-nuclear ultra luminous X-ray sources (ULX) may be evidence of the existence of black holes with masses intermediate between those produced by stellar evolution and those encountered in active galactic nuclei. We will review the observational properties of these ULXs and discuss their likely accretion regimes. We will show that some of them could...
Rodrigo Negreiros
(Universidade Federal Fluminense, Brazil)
06/05/2013, 10:15
STARS2013
Talk
Driven by the loss of energy, isolated rotating neutron stars (pulsars) are gradually slowing down to lower frequencies, which increases the tremendous compression of the matter inside of them. This increase in compression changes both the global properties of rotating neutron stars as well as their hadronic core compositions. Both effects may register themselves observationally in the thermal...
Dany Page
(Instituto de Astronomía, Universidad Nacional Autónoma de México, Mexico D.F., Mexico)
06/05/2013, 11:15
STARS2013
Talk
The year (1958) after the publication of the BCS theory, Bohr, Mottelson & Pines showed that nuclei should also contain superfluid neutrons and superconducting protons. In 1959, A. Migdal proposed that neutron superfluidity should also occur in the interior of neutron stars. Pairing in nuclei forms Cooper pairs with zero spin, but the relevant component of the nuclear interaction becomes...
Hao Tong
(Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi, China)
06/05/2013, 12:00
STARS2013
Talk
We have analyzed the physical implications of Fermi-LAT observations of magnetars. Observationally, no significant detection is reported in Fermi-LAT observations of all magnetars. We point out that there are conflicts between outer gap model in the case of magnetars and Fermi observations. One solution is that anomalous X-ray pulsars and soft gamma-ray repeaters are actually accretion...
Isaac Rodríguez
(FIAS, University of Frankfurt am Main, Germany)
06/05/2013, 14:00
STARS2013
Talk
The properties of neutron stars within the theory of pseudo-complex General Relativity are investigated. It is shown that the accumulation of dark energy, with its repulsive effects, allows the presence of neutron stars with larger masses.
Debora Menezes
(Universidade Federal de Santa Catarina, Florianópolis, Brazil)
06/05/2013, 14:30
STARS2013
Talk
We have calculated stability windows at zero [1] and finite temperature [2] for different models that are generally applied to describe quark stars: the MIT bag model, the quark mass density dependent model (QMDD) and the Nambu-Jona-Lasinio model. The quantity that has to be investigated in the search for stable strange matter at finite temperature is the free energy per baryon and we analyze...
César Oswaldo Vásquez Flores
(Federal University of ABC, Santo André, Brazil)
06/05/2013, 15:15
STARS2013
Talk
We investigate non-radial oscillations of hadronic and pure self-bound quark stars with maximum masses above the mass of the recently observed pulsar PSR J1614-2230 with M ≈ 2Mʘ. For quark stars we include the effect of strong interactions and color superconductivity. We look for features in the pulsation modes that allow a clear differentiation between hadronic and quark stars. The equations...
Gabriella Piccinelli
(Universidad Nacional Autónoma de México (UNAM), Mexico D.F., Mexico)
06/05/2013, 16:15
STARS2013
Talk
We discuss the possible effects that primordial magnetic fields and finite temperatures can have on the warm inflation scenario. This work is motivated by two considerations: first, In view of the accumulating observational evidence for their presence on all scales, the idea of a truly primordial origin of cosmic magnetism gains strength; second, the recent emergence of inflationary models...
Christoforos Kouvaris
(CP3-Origins and Danish Institute for Advanced Study, University of Southern Denmark, Odense, Denmark)
06/05/2013, 16:45
STARS2013
Talk
I will talk about how compact stars such as white dwarfs and neutron stars can impose constraints on properties of dark matter models. Dark matter accumulation into neutron stars can change the thermal evolution of the star due to dark matter annihilation taking place inside the star. In the case of asymmetric dark matter, WIMP accumulation might lead under certain conditions to the formation...
Cecilia Chirenti
(Federal University of ABC, Santo André, Brazil)
06/05/2013, 17:15
STARS2013
Talk
Newly born neutron stars can present differential rotation, even if later it should be suppressed by viscosity or a sufficiently strong magnetic field. And in this early stage of its life, a neutron star is expected to have a strong emission of gravitational waves, which could be influenced by the differential rotation. We present here a new formalism for modelling differentially rotating...
Rosalba Perna
(Department of Astrophysical and Planetary Sciences and JILA, University of Colorado, USA)
08/05/2013, 09:30
SMFNS2013
Talk
The magnetic field strength at birth is arguably one of the most important properties to determine the evolutionary path of a neutron star. Objects with very high fields, collectively known as magnetars, are characterized by high X-ray quiescent luminosities, outbursts, and, for some of them, sporadic giant flares. While the magnetic field strength is believed to drive their collective...
Martin Roth
(Leibniz Institut für Astrophysik Potsdam, Germany)
08/05/2013, 10:15
SMFNS2013
Talk
Over the last 10-15 years there has been a rapid development of the technique of integral field spectroscopy (IFS) in the optical and NIR at 4-8m telescopes, with high impact on the study of the evolution of galaxies, e.g. surveys like SAURON, ALTAS3D, CALIFA. Beyond the mere 2-dimensional mapping of extended objects, we have begun to explore the potential of PSF-fitting integral field...
Peter Hess
(FIAS, University of Frankfurt am Main, Germany)
08/05/2013, 11:15
SMFNS2013
Talk
The properties of neutron stars within the pseudo-complex General Relativity are investigated. We show that the accumulation of dark energy, with its repulsive effects, permits neutron stars with larger mass.
Shuang-Nan Zhang
(Institute of High Energy Physics, Beijing, China)
08/05/2013, 12:00
SMFNS2013
Talk
Here we report that the observed braking indices of the 366 pulsars in the sample of Hobbs et al. range from about -10^8 to about +10^8 and are significantly correlated with their characteristic ages. Using the model of magnetic field evolution we developed previously based on the same data, we derived an analytical expression for the braking index, which agrees with all the observed...
Ismael Delgado Gaspar
(Instituto de Geofísica y Astronomía, La Habana, Cuba)
08/05/2013, 15:00
SMFNS2013
Talk
We examine the near collapse dynamics of a self--gravitating magnetized electron gas at finite temperature, taken as the source of a Bianchi-I spacetime described by the Kasner metric. The set of Einstein--Maxwell field equations reduces to a complete and self--consistent system of non--linear autonomous ordinary differential equations. By considering a representative set of initial...
Lídice Cruz Rodríguez
(Facultad de Física, Universidad de La Habana, Cuba)
08/05/2013, 15:30
SMFNS2013
Talk
The aim of this work is to study Faraday rotation in the quantum relativistic limit. Starting from the polarization operator in 3D in the presence of a constant magnetic field the rotation of the polarization vector of a plane electromagnetic wave which travels along a gas electron-positron is studied. Then, its possible applications in astrophysics are discussed. The particular case of...
Norberto Scoccola
(Comisión Nacional de Energía Atómica, CONICET and Universidad Favaloro, Buenos Aires, Argentina)
08/05/2013, 16:00
SMFNS2013
Talk
We analyze the effect of strong magnetic fields on the phase diagram of strongly interacting quark matter in the context of NJL-type models. Special attention is paid to the corresponding dependence on the model parameters. In particular, the case of cold quark matter in the chiral limit is discussed in detail.
GianLuca Israel
(INAF, Osservatorio Astronomico di Roma, Monte Porzio Catone, Italy)
09/05/2013, 09:30
SMFNS2013
Talk
The Large Observatory For x-ray Timing (LOFT) is a proposed space mission intended to answer fundamental questions about, among others, the state of matter in neutron stars. LOFT was recently selected by ESA (M3) as one of the four space missions concepts of the Cosmic Vision programme that will compete for a launch opportunity at the start of the 2020s. In this talk an overview of the dense...
Debora Menezes
(Universidade Federal de Santa Catarina, Florianópolis, Brazil)
09/05/2013, 10:15
SMFNS2013
Talk
We present the number density, energy density, transverse pressure, longitudinal pressure, and magnetization of an ensemble of spin one-half particles in the presence of a homogenous background magnetic field. The magnetic field direction breaks spherical symmetry causing pressure anisotropy in the system. Explicit expressions for both charged and uncharged particles including the effect of...
Rodrigo Negreiros
(Universidade Federal Fluminense, Brazil)
09/05/2013, 11:15
SMFNS2013
Talk
We study the effects of high magnetic fields on the particle population and equation of state of hybrid stars using an extended hadronic and quark SU(3) non-linear realization of the sigma model. In this model the degrees of freedom change naturally from hadrons to quarks as the density and/or temperature increases. The effects of high magnetic fields and anomalous magnetic moment are visible...
Daryel Manreza Paret
(Facultad de Física, Universidad de La Habana, Cuba)
09/05/2013, 12:00
SMFNS2013
Talk
We investigate the effects of the anomalous magnetic moment (AMM) in the EoS of a fermion system in the presence of a magnetic field. In the region of intermediate to large magnetic fields the AMM is found from the one-loop fermion self-energy. In contrast to the weak-field AMM found by Schwinger, in the intermediate-to-large magnetic field region, the AMM depends on the Landau level and...
Zhi Fu Gao
(Xinjiang Astronomical Observatory, CAS, 150, Science 1-Street, Urumqi Xinjiang, 830011,China)
09/05/2013, 15:00
SMFNS2013
Talk
From observations, more than one-third of the detected candidate magnetars with magnetic field strengths in excess of the quantum critical value are associated with the known supernova remnants (SNRs), suggestive of an origin in massive star explosions. To date, the observational determination of braking indices of magnetars is still an open question due to strong timing noise and lake of...
Hao Tong
(Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi, China)
09/05/2013, 15:30
SMFNS2013
Talk
Considering recent observations challenging the traditional magnetar model, we explore the wind braking of magnetars. In the wind braking scenario, magnetars are neutron stars with strong multipole field. A strong dipole field is no longer necessary. Recent challenging observations of magnetars may be explained naturally in the wind braking scenario: (1) The supernova energies of magnetars are...
Lou yu-Qing
(Department of Physics and Tsinghua Center for Astrophysics, Tsinghua University, Beijing, China)
09/05/2013, 16:00
SMFNS2013
Talk
Riccardo Ciolfi
(Max Planck Institute for Gravitational Physics, AEI Potsdam, Germany)
10/05/2013, 09:30
SMFNS2013
Talk
We investigate the instability of purely poloidal magnetic fields in nonrotating neutron stars by means of three-dimensional general-relativistic magnetohydrodynamics simulations. Our aim is to draw a clear picture of the dynamics associated with a hydromagnetic instability in a neutron star and to obtain indications on possible equilibrium configurations from the final state reached by the...
Eduardo Lenho Coelho
(Universidade do Estado do Rio de Janeiro, Brazil)
10/05/2013, 10:15
SMFNS2013
Talk
Direct Urca process is an extremely efficient mechanism for cooling a proto neutron star after its formation. It is believed to be the process responsible for the cooling of young neutron stars after the first 100 years of life. One of the most interesting kind of neutron stars are the pulsars, which are highly magnetized neutron stars, with fields up to 10^14 G at the surface. It is natural...
Dany Page
(Instituto de Astronomía, Universidad Nacional Autónoma de México, Mexico D.F., Mexico)
10/05/2013, 11:15
SMFNS2013
Talk
The paradigm that pulsars are neutron stars has been established decades ago. The reverse statement, that all neutron star should appear, at least when they are young, as pulsars has been seriously challenged recently. Among the two dozens of known young (<10^4 yrs) neutron stars, less than ten actually are pulsars. Evidence for the presence of a pulsar in the remnant of SN 1987A is still...
Jorge Luis Acosta Avalo
(Facultad de Física, Universidad de La Habana, Cuba)
STARS2013
Poster
We discuss the so-called the Chiral Magnetic Effect in in QCD in a quark magnetized plasma under the wider view supplied by the consideration of the polarization modes arising from the structure of the polarization operator of charged particles in presence of an external magnetic field. We concentrate in the search of a QED analogy in a medium to the QCD chiral magnetic case, by discussing...
Marcelo Dallagnol Alloy
(Universidade Federal da Fronteira Sul, Chapecó, Brazil)
STARS2013
Poster
A protoneutron star is believed to be born from the collapse of a very massive star and a supernova explosion. During the first few seconds of the star evolution, almost all the binding energy is taken away by the neutrinos. The neutrino luminosity is controlled mainly by the total protoneutron star mass and the neutrino opacity. In this work we show that an important difference in the...
José Luis Bernal Castillo
(Universidad de Cienfuegos, Cuba)
STARS2013
Poster
Several regular black holes solutions have been constructed since 1968 afther Bardeen's proposal of coupling gravity with external form of matter. In the present work a detailed study of massless fermion perturbations outside somke regular black hole solutions is carried out. We present the object picture of the complete time evolution and compute the quasinormal frecuencies at intermediate...
Sergio Mittmann dos Santos
(IFRS, Porto Alegre, Brazil)
STARS2013
Poster
The Brans-Dicke theory of gravitation is a scalar-tensor theory, which foresees the gravitational interaction being mediated not only by the graviton, but also by a scalar field. The theory is recently being studied, because it seems to be more appropriate for understanding the early formation of the Universe and has contributed to the development of unified theories of fundamental...
Dagoberto Escobar Atienzar
(Universidad de Camagüey, Cuba)
STARS2013
Poster
We analyze the slow-roll inflation within a brane framework with a real Higgs field confined at the brane. We prove that inflation occurs for field value below the 4- dimensional Planck scale and produces cosmological perturbations in accordance with observations. We find the dependence of the spectral index with the Higgs mass, the obtained result from running of the spectral index in the...
Alexandre Santos
(Universidade Federal de Santa Catarina - Campus Curitibanos, Brazil)
STARS2013
Poster
We investigate compact star properties within the quark meson coupling model (QMC) with a soft symmetry energy density dependence at large densities. It is shown that a softer symmetry energy gives rise to stars with less hyperons, smaller radii and larger masses, where the hyperon-meson couplings are chosen according to experimental values of the hyperon nuclear matter potentials, and...
