Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Foundations of Chiral Perturbation Theory   The properties of the effective field theory relevant for the low energy
structure generated by the Goldstone bosons of a spontaneously broken symmetry
are reexamined. It is shown that anomaly free, Lorentz invariant theories are
characterized by a gauge invariant effective Lagrangian, to all orders of the
low energy expansion. The paper includes a discussion of anomalies and
approximate symmetries, but does not cover nonrelativistic effective theories.

15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc