Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Matters of Gravity, The Newsletter of The Topical Group in Gravitation
  of the American Physical Society, Volume 27, Spring 2006   GGR News:
  GGR program at the APS April meeting in Dallas
  We hear that..., 100 years ago, by Jorge Pullin
  Research Briefs:
  What's new in LIGO, by David Shoemaker
  LISA Pathfinder, by Paul McNamara
  Recent progress in binary black hole simulations, by Thomas Baumgarte
  Conference reports:
  Workshop on Emergence of Spacetime, by Olaf Dreyer
  Quantum gravity subprogram at the Isaac Newton Institute, by Jorma Louko
  Global problems in Math Relativity at the Newton Institute, by Jim Isenberg
  Loops '05, by Thomas Thiemann
  Numrel 2005, by Scott Hawley and Richard Matzner
  Apples With Apples Workshop in Argentina, by Sascha Husa

34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph