The theoretical structure of the pion-photon interaction amplitudes at low energies and the possibility of studying them experimentally are reviewed. It is pointed out that it is possible to measure the $\pi\pi$ scattering lengths in photon-pion transitions. For processes involving an odd number of pions, a discussion is given of the fundamental role of the $\pi^0\to2\gamma$ decay amplitude, which determines the form of all more complex amplitudes. This fact is connected with the anomalies in the axial-vector current that appears in the weak interaction. In processes involving an even number of pions, the radius and polarizability of the $\pi^-$ meson appear as basic parameters. The polarizability is related to the weak decay amplitude.

@article{Terent’ev:1974,
	author = {M. V. Terent’ev},
	title = {Electromagnetic properties of pions at low energies},
	publisher = {Physics-Uspekhi},
	year = {1974},
	journal = {Phys. Usp.},
	volume = {17},
	number = {1},
	pages = {20-43},
	url = {https://ufn.ru/en/articles/1974/1/b/},
	doi = {10.1070/PU1974v017n01ABEH004315}
}