G. Mueller

TL;DR: The Pierre Auger Observatory as mentioned in this paper, the world's largest cosmic ray observatory, has been in successful operation since completion in 2008 and has recorded data from an exposure exceeding 40,000 km$^2$ sr yr.

TL;DR: A review of the physics motivation for dark sectors and the exciting opportunities for experimental exploration is provided in this article, where axions, which solve the strong CP problem and are an excellent dark matter candidate, and their generalization to axion-like particles.

TL;DR: In this paper, the authors report on the constraints these observations place on the rate of binary black hole coalescences, and estimate a 90% credible range of merger rates between $2$--$53 \, \mathrm{Gpc}^{-3} \mathm{yr}^{ −1}$ (comoving frame).

TL;DR: The sensitivity of the LIGO network to transient gravitational-wave signals is estimated, and the capability of the network to determine the sky location of the source is studied, to facilitate planning for multi-messenger astronomy with gravitational waves.

TL;DR: In this article, the authors examined the implications of the distributions of the depths of atmospheric shower maximum (X-max) using a hybrid technique, for composition and hadronic interaction models, and found that their data are not well described by a mix of protons and iron nuclei over most of the energy range.