[Commits] [svn:einsteintoolkit] Paper_EinsteinToolkit_2010/ (Rev. 264)

[roland.haas at physics.gatech.edu]

User: rhaas
Date: 2012/03/06 07:15 PM

Modified:
 /
  ET.tex

Log:
 add some text explaining parallelism in TwoPunctures and Lorene and why TP is
 usually used on line but Lorene is not
 
 add some LaTeX code to provide a bibfont command indep of whether it has been
 defined before or not

File Changes:

Directory: /
============

File [modified]: ET.tex
Delta lines: +20 -6
===================================================================
--- ET.tex	2012-03-07 00:39:13 UTC (rev 263)
+++ ET.tex	2012-03-07 01:15:39 UTC (rev 264)
@@ -28,7 +28,14 @@
 \usepackage[all]{hypcap}
 
 \usepackage[sort&compress,numbers]{natbib}
+% RH: we might have to remove the ifx stuff for submission, but it allows both
+% Bruno, Roland and Peter to build this file and all have \bibfont be
+% \footnotesize
+\ifx\bibfont\relax
+\newcommand{\bibfont}{\footnotesize}
+\else
 \renewcommand{\bibfont}{\footnotesize}
+\fi
 
 \graphicspath{{figures/}
 {cactus-benchmarks/}
@@ -286,7 +293,7 @@
 component's function is explained and, if applicable, the physical system it
 models is introduced. The next major section, Section~\ref{sec:examples},
 contains a set of sample results obtained using the toolkit's components.
-Examples from numerical relativity, astrophysics and cosmolology are provided.
+Examples from numerical relativity, astrophysics and cosmology are provided.
 
 \section{Requirements}%
 \label{sec:requirements}
@@ -949,7 +956,13 @@
 The most widely used routine to generate initial data for these is the 
 \codename{TwoPunctures} code (described originally in~\cite{Ansorg:2004ds}) which solves 
 the binary puncture equations for a pair of BHs~\cite{Brandt:1997tf}.
-To do so, one assumes the extrinsic curvature for each BH corresponds to 
+\codename{TwoPunctures} is a serial code that does not parallelize
+beyond a single node through the use of \codename{OpenMP}. Nevertheless it has
+proven sufficiently robust and fast that the vacuum initial data problem is
+usually solved on-line at the beginning of an inspiral simulation. This
+approach allows all information required to set up the run to be kept in the
+single \codename{Cactus} parameter file.
+\codename{TwoPunctures} assumes the extrinsic curvature for each BH corresponds to 
 the Bowen-York form~\cite{Bowen:1980yu}:
 \begin{eqnarray}
 K_{(m)}^{ij}&=&\frac{3}{2r^2}(p_{(m)}^i\hat{N}^j+p_{(m)}^j\hat{N}^i-(\gamma^{ij}-\hat{N}^i\hat{N}^j)p_{(m)}^k\hat{N}_k))\nonumber\\
@@ -1007,10 +1020,11 @@
 by the {\tt Lorene} code~\cite{Lorene:web,Gourgoulhon:2000nn}, though it does not 
 currently include the capability of generating such data from scratch.  For a 
 number of reasons, such functionality is not truly required; in particular, 
-{\tt Lorene} is a serial code and to call it as 
-an Einstein Toolkit initial data generator saves no time.  Also, it is not guaranteed to be convergent for 
-an arbitrary set of parameters; thus the initial data routine itself may never 
-finish its iterative steps.  Instead, recommended practice is to let Lorene output 
+{\tt Lorene} is often used to generate initial data involving neutron stars,
+where the initial data problem is sufficiently hard that finding a numerical
+solution requires a significant amount of computer time as well as some human
+oversight in order to guide the routine to the correct solution. 
+Therefore, recommended practice is to let Lorene output 
 data into files, and then read those into the Einstein Toolkit at the beginning of a run.
 
 Lorene uses a multigrid spectral approach to solve the conformal thin-sandwich