Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Elements of causality theory   These notes present some elements of causality theory. While they are not as
complete as other treatments of the topic, there is some originality in that
the whole approach is based on a definition of causal curves which allows to
simplify many arguments. We keep track of the differentiability needed for
various statements, obtaining a coherent theory for
twice-continuously-differentiable metrics.

8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg