Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Relativistic Perturbations of Second and Higher Order   We present the results of a study of the gauge dependence of spacetime
perturbations. In particular, we consider gauge invariance in general, we give
a generating formula for gauge transformations to an arbitrary order n, and
explicit transformation rules at second order.

20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph