User: knarf Date: 2011/11/11 09:27 AM

Modified: / ET.tex

Log: some rewording from Dennis

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File [modified]: ET.tex Delta lines: +42 -46 =================================================================== --- ET.tex 2011-11-11 15:13:47 UTC (rev 183) +++ ET.tex 2011-11-11 15:27:00 UTC (rev 184) @@ -121,25 +121,22 @@ % to be used

\begin{abstract} -We describe the Einstein Toolkit, a community-driven, freely -accessible computational infrastructure intended for use in numerical -relativity, relativistic astrophysics, and other applications. The -Toolkit, developed by a collaboration involving researchers from -several institutions around the world, combines a core set of -components needed to simulate astrophysical objects including black -holes, compact objects, and collapsing stars, as well as a full suite -of analysis tools. The Einstein Toolkit is based on the Cactus -Framework for high-performance computing and the Carpet adaptive mesh -refinement driver. It implements spacetime evolution via the BSSN -evolution system and general-relativistic hydrodynamics in a -finite-volume discretization. The toolkit is under continuous -development and contains many new code components that have been -publicly released for the first time and are described in this -article. We discuss the motivation behind the release of the toolkit, -the philosophy underlying its development, and the goals of the -project. A summary of the implemented numerical techniques is -included, as are results of numerical test covering a variety of -sample astrophysical problems. +We describe the Einstein Toolkit, a community-driven, freely accessible +computational infrastructure intended for use in numerical relativity, +relativistic astrophysics, and other applications. The Toolkit, developed by a +collaboration involving researchers from several institutions around the world, +combines a core set of components needed to simulate astrophysical objects such +as black holes, compact objects, and collapsing stars, as well as a full suite +of analysis tools. The Einstein Toolkit is based on the Cactus Framework for +high-performance computing and the Carpet adaptive mesh refinement driver. It +implements spacetime evolution via the BSSN evolution system and +general-relativistic hydrodynamics in a finite-volume discretization. The +toolkit is under continuous development and contains many new code components +that have been publicly released for the first time and are described in this +article. We discuss the motivation behind the release of the toolkit, the +philosophy underlying its development, and the goals of the project. A summary +of the implemented numerical techniques is included, as are results of +numerical test covering a variety of sample astrophysical problems. \end{abstract}

\pacs{04.25.D-, 04.30.-w, 04.70.-s, 07.05.Tp, 95.75.Pq} @@ -166,7 +163,7 @@ advances for the next few years~\cite{Shibata:1999wm,Shibata:2002jb, Shibata:2003ga,Shibata:2005ss,Shibata:2006nm}, systems containing BHs proved much more numerically intractable until 2005. That year, computational -breakthroughs were made in using a generalized harmonic gauge (GHG) +breakthroughs were made using a generalized harmonic gauge (GHG) \cite{Pretorius:2005gq} and then a ``moving puncture'' approach \cite{Campanelli:2005dd, Baker:2005vv} in the BSSN (Baumgarte-Shapiro-Shibata-Nakamura) formalism~\cite{Shibata:1995we,Baumgarte:1998te} @@ -199,7 +196,7 @@ on fixed background spacetimes has been implemented in multi-dimensional settings since the mid-1990s, focusing on BH accretion processes and relativistic jet production and evolution -(see, e.g.,~\cite{Font:2008aa} for a review of the numerical formalism, +(see~\cite{Font:2008aa} for a review of the numerical formalism and~\cite{Hawley2009apss} for a review of work on disk and jet models). GRMHD coupled with curvature evolution, on the other hand, which is crucial for modeling large-scale bulk @@ -209,7 +206,7 @@ stable curvature evolution systems discussed above as well as improved GRMHD algorithms~(see~\cite{Font:2008aa} for a review). In addition to these developments, substantial progress has been made -in using physically motivated equations of state (EOS), +using physically motivated equations of state (EOS), including tabulated versions (e.g.,~\cite{Pandharipande:1989hn, Douchin:2001sv,Akmal:1998cf}) and temperature-dependent models (e.g.,~\cite{Shen:1998by,Shen:1998gq,Lattimer:1991nc}). Some codes also @@ -228,27 +225,27 @@ now include GRMHD (used widely for NS-NS mergers, and for BH-NS mergers in~\cite{Chawla:2010sw}, and some include microphysical effects as well. The groups that have reported simulations of NS-NS or BH-NS mergers include: -\begin{description} -\item[AEI/Sissa]: BH-NS mergers using GRHD~\cite{Loffler:2006nu} and NS-NS +\begin{itemize} +\item {\bf AEI/Sissa}: BH-NS mergers using GRHD~\cite{Loffler:2006nu} and NS-NS mergers using GRHD~\cite{Baiotti:2008ra,Baiotti:2009gk,Baiotti:2010xh, Baiotti:2011am,Rezzolla:2010fd} and GRMHD~\cite{Giacomazzo:2009mp, Giacomazzo:2010bx,Rezzolla:2011da}. -\item[Caltech/Cornell]: A {\em pseudospectral}, GRHD code has been used +\item {\bf Caltech/Cornell}: A {\em pseudospectral}, GRHD code has been used to simulate BH-NS mergers~\cite{Duez:2008rb,Duez:2009yy,Foucart:2010eq}. -\item[Illinois]: BH-NS mergers using GRHD~\cite{Etienne:2007jg,Etienne:2008re} +\item {\bf Illinois}: BH-NS mergers using GRHD~\cite{Etienne:2007jg,Etienne:2008re} and NS-NS mergers using GRMHD~\cite{Liu:2008xy}. -\item[Jena]: NS-NS mergers using GRHD~\cite{Thierfelder:2011yi}. -\item[LSU/BYU/LIU]: BH-NS mergers using GRMHD~\cite{Chawla:2010sw} and +\item {\bf Jena}: NS-NS mergers using GRHD~\cite{Thierfelder:2011yi}. +\item {\bf LSU/BYU/LIU}: BH-NS mergers using GRMHD~\cite{Chawla:2010sw} and NS-NS mergers using GRHD~\cite{Anderson:2007kz} and GRMHD~\cite{Anderson:2008zp}. -\item[Princeton]: BH-NS mergers using GRHD~\cite{Stephens:2011as}. -\item[Tokyo/Kyoto]: BH-NS mergers using GRHD~\cite{Shibata:2006bs, +\item {\bf Princeton}: BH-NS mergers using GRHD~\cite{Stephens:2011as}. +\item {\bf Tokyo/Kyoto}: BH-NS mergers using GRHD~\cite{Shibata:2006bs, Shibata:2006ks,Shibata:2007zm,Yamamoto:2008js,Shibata:2009cn, Kyutoku:2010zd,Shibata:2010zz} and NS-NS mergers using GRHD \cite{Yamamoto:2008js,Kiuchi:2009jt, Kiuchi:2010ze,Hotokezaka:2011dh}, most recently with the inclusion of neutrino cooling~\cite{Sekiguchi:2011zd}. \todo{Check for updates to list before submission!} -\end{description} +\end{itemize}

In addition to studying binary mergers, numerical relativity is a necessary element for understanding stellar collapse and dynamical instabilities @@ -261,31 +258,30 @@ rapidly rotating polytropic NS models~\cite{Shibata:1999yx,Baiotti:2006wn, Manca:2007ca}.

-In parallel to the advances in both our physical understanding of +Simultanious to the advances in both our physical understanding of relativistic dynamics and the numerical techniques required to study them, a set of computational tools and libraries has been developed with the -aim of providing a computational core that can enable the new science, +aim of providing a computational core that can enable new science, broaden the community, facilitate interdisciplinary research and take advantage of emerging petascale computers and advanced cyberinfrastructure: -the {\tt Cactus} computational toolkit~\cite{Cactuscode:web}. While it was -developed in large part by -computer scientists, its development was driven by the direct input from other -fields, especially numerical relativity, succeeding in applying expertise in -computer science directly to problems in numerical relativity. +the Cactus computational toolkit~\cite{Cactuscode:web}. While it was +developed in large part by computer scientists, its development was driven by +direct input from other fields, especially numerical relativity, and has +succeeded in applying expertise in computer science directly to problems in +numerical relativity.

This success prompted usage of the {\tt Cactus} computational toolkit in other areas, such as ocean forecast models~\cite{Djikstra2005} and chemical reaction simulations~\cite{Camarda2001}. At the same time, the growing number of results in numerical relativity increased the need for commonly available utilities such as comparison and analysis tools, typically -those specifically designed for astrophysical problems. Including them -within the -{\tt Cactus} computational toolkit was not felt to fit within its rapidly -expanding scope. This triggered -the creation of the Einstein Toolkit~\cite{EinsteinToolkit:web}. While large -parts of the Einstein toolkit -presently do make use of the {\tt Cactus} toolkit, this is not an requirement at all, -and other contributions are welcome and have been accepted. +those specifically designed for astrophysical problems. Including them within +the {\tt Cactus} computational toolkit was not felt to fit within its rapidly +expanding scope. This triggered the creation of the Einstein +Toolkit~\cite{EinsteinToolkit:web}. Large parts of the Einstein toolkit +presently do make use of the {\tt Cactus} toolkit, but this is not an +requirement, and other contributions are welcome, encouraged and have been +accepted in the past.

\section{Requirements}