These revisions were done exclusively by Adamo
and Newman, therefore the author order was slightly changed. There was nothing essentially wrong in the
earlier version, but we have included several new results (in the text and in appendices), corrected an error
of interpretation in Section 7, and (the main reason for the revision) we found much easier ways of doing
some of the long calculations with very much simpler arguments. Roughly the changes are: Aside from a few
word changes,
- We have extended the glossary at the beginning by including a Table 2 for the geometric
quantities.
- In Section 3.2 we have added in a fair amount to the discussion of real structures associated
with the complex world lines.
- The major revisions are in Section 6. Here we basically rewrote the entire section; i.e., the
derivation of our major results, using much simpler arguments. This greatly shortened the
derivation and associated argument.
- In the Section 7, we corrected an error in the discussion of representation theory.
- We added items in Section 8 and changed some of the wording in Section 8.1.
- 19 new references were added.
- The Acknowledgements 9 were changed.
- Two new Appendices (E, F) were added presenting new material found since the previous
version.