Institution
International School for Advanced Studies
Education•Trieste, Friuli-Venezia Giulia, Italy•
About: International School for Advanced Studies is a education organization based out in Trieste, Friuli-Venezia Giulia, Italy. It is known for research contribution in the topics: Galaxy & Dark matter. The organization has 3751 authors who have published 13433 publications receiving 588454 citations. The organization is also known as: SISSA & Scuola Internazionale Superiore di Studi Avanzati.
Papers published on a yearly basis
Papers
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TL;DR: In this paper, the early-time afterglow light curve carries information about 0, which determines the time of the peak of the gamma-ray burst (GRB) peak.
Abstract: Context. Gamma-ray burst (GRB) emission is believed to originate in highly relativistic fireballs. Aims. Currently, only lower limits were securely set to the initia l fireball Lorentz factor 0. We aim to provide a direct measure of 0. Methods. The early-time afterglow light curve carries information about 0, which determines the time of the afterglow peak. We have obtained early observations of the near-infrared afte rglows of GRB 060418 and GRB 060607A with the REM robotic telescope. Results. For both events, the afterglow peak could be clearly singled out, allowing a firm determination of the fireball Lorentz of 0∼ 400, fully confirming the highly relativistic nature of GRB fi reballs. The deceleration radius was inferred to be Rdec≈ 10 17 cm. This is much larger than the internal shocks radius (believed to power the prompt emission), thus providing further evidence for a different origin of the prompt and afterglow stages of the GRB.
253 citations
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TL;DR: The individual elastic constants of magnesium oxide (MgO) have been determined throughout Earth's lower mantle (LM) pressure-temperature regime with density functional perturbation theory and it is shown that temperature effects on seismic observables are monotonically suppressed with increasing pressure.
Abstract: The individual elastic constants of magnesium oxide (MgO) have been determined throughout Earth's lower mantle (LM) pressure-temperature regime with density functional perturbation theory. It is shown that temperature effects on seismic observables (density, velocities, and anisotropy) are monotonically suppressed with increasing pressure. Therefore, at realistic LM conditions, the isotropic wave velocities of MgO remain comparable to seismic velocities, as previously noticed in athermal high-pressure calculations. Also, the predicted strong pressure-induced anisotropy is preserved toward the bottom of the LM, so lattice-preferred orientations in MgO may contribute substantially to the observed seismic anisotropy in the D" layer.
253 citations
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TL;DR: Given a compact four dimensional manifold, it is proved existence of conformal metrics with constant Q-curvature under generic assumptions, jointly with the compactness result of [35].
Abstract: Given a compact four dimensional manifold, we prove existence of conformal metrics with constant Q-curvature under generic assumptions. The problem amounts to solving a fourth-order nonlinear elliptic equation with variational structure. Since the corresponding Euler functional is in general unbounded from above and from below, we employ topological methods and min-max schemes, jointly with the compactness result of [35].
253 citations
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TL;DR: In this article, multiple semiclassical standing waves for a class of nonlinear Schrodinger equations with potentials were found by means of a perturbative variational method.
Abstract: Multiple semiclassical standing waves for a class of nonlinear Schrodinger equations with potentials are found by means of a perturbative variational method.
252 citations
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TL;DR: In this paper, the authors studied the gamma-ray burst emission observed at energies > 100 MeV by the Fermi-Large Area Telescope (LAT) until 2009 October and showed that the observed > 0.1 GeV flux can be interpreted as afterglow emission shortly following the start of the prompt phase emission as seen at smaller frequencies.
Abstract: We study the emission observed at energies > 100 MeV of 11 gamma-ray bursts (GRBs) detected by the Fermi-Large Area Telescope (LAT) until 2009 October. The GeV emission has three main properties: (i) its duration is often longer than the duration of the softer emission detected by the Gamma Burst Monitor onboard Fermi (this confirms earlier results from the Energetic Gamma-Ray Experiment Telescope); (ii) its spectrum is consistent with F ν ∝ ν ―1 and does not show strong spectral evolution; and (iii) for the brightest bursts the flux detected by the LAT decays as a power law with a typical slope t ―1.5 . We argue that the observed >0.1 GeV flux can be interpreted as afterglow emission shortly following the start of the prompt phase emission as seen at smaller frequencies. The decay slope is what is expected if the fireball emission is produced in the radiative regime, i.e. all dissipated energy is radiated away. We also argue that the detectability in the GeV energy range depends on the bulk Lorentz factor Γ of the bursts, being strongly favoured in the case of large Γ. This implies that the fraction of bursts detected at high energies corresponds to the fraction of bursts having the largest r. The radiative interpretation can help to explain why the observed X-ray and optical afterglow energetics are much smaller than the energetics emitted during the prompt phase, despite the fact that the collision with the external medium should be more efficient than internal shocks in producing the radiation that we see.
252 citations
Authors
Showing all 3802 results
Name | H-index | Papers | Citations |
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Sabino Matarrese | 155 | 775 | 123278 |
G. de Zotti | 154 | 718 | 121249 |
J. González-Nuevo | 144 | 500 | 108318 |
Matt J. Jarvis | 144 | 1064 | 85559 |
Carlo Baccigalupi | 137 | 518 | 104722 |
L. Toffolatti | 136 | 376 | 95529 |
Michele Parrinello | 133 | 637 | 94674 |
Marzio Nessi | 129 | 1046 | 78641 |
Luigi Danese | 128 | 394 | 92073 |
Lidia Smirnova | 127 | 944 | 75865 |
Michele Pinamonti | 126 | 846 | 69328 |
David M. Alexander | 125 | 652 | 60686 |
Davide Maino | 124 | 410 | 88117 |
Dipak Munshi | 124 | 365 | 84322 |
Peter Onyisi | 114 | 694 | 60392 |