Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Static- and Stationary-complete Spacetimes: Algebraic and Causal
  Structures   This is intended as an analysis of the global properties of static and
stationary spacetimes with complete (timelike) Killing field, with particular
attention to quotients by group actions. This is presented in terms of
algebraic structures which are fairly simple for the static case and more
involved for the stationary case; the most important tool, the fundamental
cocycle, is a cohomological class for static spacetimes but of somewhat looser
structure in the stationary case.
  In particular: (1) A new measurement, similar to the spacetime interval in
Minkowski space, is devised for detecting whether two points are causally
related in a stationary spacetime; this proves very useful for analysis. (2)
All stationary spacetimes are categorized by how they behave with respect to
the fundamental cocycle; this enables a complete characterization of global
causality properties. (3) It is shown how these tools determine whether global
hyperbolicity of a stationary spacetime is inherited by its quotients. (4)
Examples are examined in detail, a large range including both ones of
mathematical curiosity and ones of physical interest, such as cosmic strings in
flat, accelerated, Schwarzschild, Kerr, and other backgrounds.

8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci