106,660 research outputs found
Going Global: A Faculty Connection between Peru and the United States
In 2003, the University System of Georgia sponsored the Peru Summer Institute for Faculty Development. A fortuitous meeting between Peruvian and U.S. faculty led to a faculty exchange with the shared goals of expanding cultural horizons, enhancing faculty through improved teaching and collaboration, and preparing students for the increasingly global reach of information technology. The experiences of this faculty exchange provide a framework for future collaboration between Peruâs information technology professionals and their colleagues in the United States. But perhaps more importantly, faculty and students discovered a synergy between designing information technology systems and the cultural contexts under which such systems operate
An introduction to local Black Hole horizons in the 3+1 approach to General Relativity
We present an introduction to dynamical trapping horizons as quasi-local
models for black hole horizons, from the perspective of an Initial Value
Problem approach to the construction of generic black hole spacetimes. We focus
on the geometric and structural properties of these horizons aiming, as a main
application, at the numerical evolution and analysis of black hole spacetimes
in astrophysical scenarios. In this setting, we discuss their dual role as an
"a priori" ingredient in certain formulations of Einstein equations and as an
"a posteriori" tool for the diagnosis of dynamical black hole spacetimes.
Complementary to the first-principles discussion of quasi-local horizon
physics, we place an emphasis on the "rigidity" properties of these
hypersurfaces and their role as privileged geometric probes into near-horizon
strong-field spacetime dynamics.Comment: 37 pages, 5 figures. Notes prepared for the course at the 2011
Shanghai Asia-Pacific School and Workshop on Gravitation (Shanghai Normal
University, February 10-14, 2011
Horizons in the near-equilibrium regime
Quasi-static systems are an important concept in thermodynamics: they are
dynamic but close enough to equilibrium that many properties of equilibrium
systems still hold. Slowly evolving horizons are the corresponding concept for
quasilocally defined black holes: they are "nearly isolated" future outer
trapping horizons. This article reviews the definition and properties of these
objects including both their mechanics and the role that they play in the
fluid-gravity correspondence. It also introduces a new property: there is an
event horizon candidate in close proximity to any slowly evolving horizon.Comment: 19 pages, 2 figures, will appear as a chapter of "Black Holes: New
Horizons" edited by S. Haywar
Recent results in mathematical relativity
We review selected recent results concerning the global structure of
solutions of the vacuum Einstein equations. The topics covered include
quasi-local mass, strong cosmic censorship, non-linear stability, new
constructions of solutions of the constraint equations, improved understanding
of asymptotic properties of the solutions, existence of solutions with low
regularity, and construction of initial data with trapped surfaces or apparent
horizons.
This is an expanded version of a plenary lecture, sponsored by Classical and
Quantum Gravity, held at the GR17 conference in Dublin in July 2004.Comment: 16 pages, to appear in the proceedings of GRG17, Dubli
Integrated Management: A Coastal Community Perspective
This paper was prepared for the Food and Agriculture Organisation of the United Nations Regional Workshops on Small-Scale Fisheries "Securing Sustainable Small-Scale Fisheries: Bringing together responsible fisheries and social development". It presents a review of what are seen as 'good practices' globally in policy and governance of small-scale fisheries, with a particular focus on addressing rights-based issues, viewed broadly as incorporating fishery rights, other rights to natural resources, and rights and entitlements in relation to human, social and economic rights. It draws extensively on the 1995 Code of Conduct for Responsible Fisheries and related technical guidelines, particularly those concerning small-scale fisheries and their roles in poverty alleviation and food security, and the human dimensions of the ecosystem approach to fisheries. The paper is also strongly informed by the papers prepared for and outcomes of the 2008 Global Conference on "Securing Sustainable Small-Scale Fisheries: Bringing together responsible fisheries and social development" and the relevant rights-oriented components of the 'Bangkok Statement' produced by the Civil Society Preparatory Workshop for the Global Conference. It also draws upon a set of research documents in the international literature focusing on small-scale fisheries and related policy issues [e.g., Allison et al. (2010), Charles (2009, 2011), McConney and Charles (2009); Kurien (2000, 2007)]
From Geometry to Numerics: interdisciplinary aspects in mathematical and numerical relativity
This article reviews some aspects in the current relationship between
mathematical and numerical General Relativity. Focus is placed on the
description of isolated systems, with a particular emphasis on recent
developments in the study of black holes. Ideas concerning asymptotic flatness,
the initial value problem, the constraint equations, evolution formalisms,
geometric inequalities and quasi-local black hole horizons are discussed on the
light of the interaction between numerical and mathematical relativists.Comment: Topical review commissioned by Classical and Quantum Gravity.
Discussion inspired by the workshop "From Geometry to Numerics" (Paris, 20-24
November, 2006), part of the "General Relativity Trimester" at the Institut
Henri Poincare (Fall 2006). Comments and references added. Typos corrected.
Submitted to Classical and Quantum Gravit
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