3:30 pm MCP 201
Axions were originally introduced as a byproduct in solving the strong CP problem in quantum chromodynamics (QCD) and are also excellent candidates for dark matter. Compared to Weakly Interacting Massive Particles (WIMPs), axions exhibit a distinct nature: they behave like classical waves owing to their long de Broglie wavelength and the high occupation number of axion particles. Through the inverse Primakoff effect, which converts axions into microwaves, typical axion searches involve challenges in classical microwave technology, such as the development of high-quality and tunable resonant cavities. In this seminar, we will review the fundamental properties of these conventional “classical” axions and briefly explore phenomena beyond this regime—namely, the “quantum” aspects of axions, particularly those associated with relatively heavy axions predicted in post-inflationary scenarios.