User: eschnett Date: 2011/04/17 09:40 PM
Modified: / ET.tex
Log: Update QLM section
File Changes:
Directory: / ============
File [modified]: ET.tex Delta lines: +17 -6 =================================================================== --- ET.tex 2011-04-18 02:30:45 UTC (rev 59) +++ ET.tex 2011-04-18 02:40:49 UTC (rev 60) @@ -1325,16 +1325,27 @@ the domain as these quantities are only properly interpretable when calculated at infinity.
-Second, there are the quasi-local measures of mass and momentum. From +Second, there are the quasi-local measures of mass and angular momentum. From any \ahz{s} found during the spacetime, both \codename{AHFinderDirect} and \codename{AHFinder} output the corresponding mass derived from the area of the horizon $m_H = -\sqrt{A/(16\pi)}$. In addition, the module \codename{QuasiLocalMeasures} -takes a specified surface, generally a previously located \ahz{} -and calculates the mass, spin and their moments, among other quantities, -on the surface based on the isolated and dynamical horizon framework. -\todo{... is this what it does? ...} +\sqrt{A/(16\pi)}$.
+In addition, the module \codename{QuasiLocalMeasures} implements +certain equations from the isolated and dynamical horizon formalisms, +as well as certain extensions defining quasi-local quantities; +quasi-local quantities are quantities that are gauge independent, but +depend on the choice of a particular two-sphere in a spacetime. In +this sense, \codename{QuasiLocalMeasures} can provide +gauge-independent measures of e.g.\ mass and angular momentum of +regions of the spacetime enclosed in a two-sphere. +\codename{QuasiLocalMeasures} takes as input a horizon surface any +other surface that the user specifies, such as a large coordinate +sphere, and calculates can calculate mass, angular momentum, or other +quantities such as the Weyl or Ricci scalars, multipole moments of the +horizon geometry, or the three-volume element of the horizon world +tube. + Finally, the module \codename{HydroAnalysis} additionally locates the center of mass as well as the point of maximum rest mass density of a matter field.