Thanks Waldyr
:-)
On Apr 14, 2012, at 9:38 AM, Waldyr A. Rodrigues Jr. wrote:

Dear Jack,
You should read my comments on LDG gauge theory of gravitation in Appendix F of my book:
Gravitation as a Plastic Distortion of the Lorentz Vacuum. For your convenience a copy of the book is attached. You can put a link to the book and to an errata if you think that this is worthwhile. The links are:
 
http://www.springer.com/physics/theoretical,+mathematical+%26+computational+physics/book/978-3-642-13588-0
 
 
http://www.ime.unicamp.br/~walrod/errataplastic.pdf
 
A free copy with almost the same material can be obtained from:http://arxiv.org/abs/0909.4472