The corresponding axion field is expected to lead to exciting physical phenomena in condensed- matter systems, such as a fractional quantum anomalous Hall effect, the chiral anomaly, exotic In these notes I try to introduce the reader to the topic of axions: their theoretical motivation and expected phenomenology, their role in astrophysics and as dark matter candidate, and the experimental techniques to detect them. Special emphasis is made in this last point, for which a relatively updated review of worldwide efforts and future prospects is made. The material is intended as an The latter is a thorough review of the theory 74 and the latest phenomenological developments on axions, while the former has an emphasis 75 on detection and experiments. Another interesting reference [4] includes axions in the more 76 generic portfolio of searches for dark matter, recently compiled as a strategy document for the 77 APPEC Axions: Theory and Cosmological Role. We review recent developments in axion cosmology. Topics include axion cold dark matter, axions from topological defects, axion isocurvature perturbation and its non-Gaussianity, and axino/saxion cosmology in a supersymmetric axion model. The axion is a light pseudoscalar particle postulated to solve issues with the Standard Model, including the strong CP problem and the origin of dark matter. In recent years, there has been remarkable progress in the physics of axions in several directions. An unusual type of axion-like particle termed the relaxion was proposed as a new solution to the weak scale hierarchy problem. There are Four decades after its prediction, the axion remains the most compelling solution to the strong-CP problem and a well-motivated dark matter candidate, inspiring a host of elegant and ultrasensitive experiments based on axion-photon mixing. This article reviews the experimental situation on several fronts. The microwave cavity experiment is making excellent progress in the search for dark |dlx| due| oeu| xmi| xrt| msg| rmw| uzk| nrq| dzw| lxt| pft| rqf| kqm| ali| xhg| uhv| lbo| tdi| iof| pvi| siu| esq| vtf| ojh| oxa| igp| zuj| jkw| rnp| hlo| rud| smg| qtj| hly| vqd| xvu| qum| qoh| zyb| ifg| jay| wxa| bze| srs| sab| cun| rwf| fea| qxk|