Recent experiments on magnets put inside optical and microwave cavities demonstrated a variety of interesting phenomena. After an extensive introduction, we will first concentrate on asymmetry of Stokes and anti-Stokes peaks in light transmission through a cavity and present a theory which explains this difference and also predicts only one peak in reflection [1]. After that, we will discuss cooling of magnons with light [2].

[1] S. Sharma, Ya. M. Blanter, and G. E. W. Bauer, Phys. Rev. B 96, 094412 (2017)
[2] S. Sharma, Ya. M. Blanter, and G. E. W. Bauer, Phys. Rev. Lett. 121, 087205 (2018)