Homogeneity and planewave limits
Abstract
We explore the planewave limit of homogeneous spacetimes. For planewave limits along homogeneous geodesics the limit is known to be homogeneous and we exhibit the limiting metric in terms of Lie algebraic data. This simplifies many calculations and we illustrate this with several examples. We also investigate the behaviour of (reductive) homogeneous structures under the planewave limit.
 Publication:

Journal of High Energy Physics
 Pub Date:
 May 2005
 DOI:
 10.1088/11266708/2005/05/050
 arXiv:
 arXiv:hepth/0504069
 Bibcode:
 2005JHEP...05..050F
 Keywords:

 Penrose limit and ppwave background Differential and Algebraic Geometry;
 High Energy Physics  Theory;
 Mathematics  Differential Geometry
 EPrint:
 In memory of Stanley Hobert, 33 pages. Minor corrections and some simplification of Section 4.3.1