We review applications of string theory to cosmology, from primordial times to the present-
day accelerated expansion. Starting with a brief overview of cosmology and string …

Abstract The Laser Interferometer Space Antenna (LISA) has two scientific objectives of
cosmological focus: to probe the expansion rate of the universe, and to understand …

We provide a review on the state-of-the-art of gravitational waves induced by primordial
fluctuations, so-called induced gravitational waves. We present the intuitive physics behind …

We review the landscape of QCD axion models. Theoretical constructions that extend the
window for the axion mass and couplings beyond conventional regions are highlighted and …

The Swampland program aims to distinguish effective theories which can be completed into
quantum gravity in the ultraviolet from those which cannot. This article forms an introduction …

We report on the implications for cosmic inflation of the 2018 release of the Planck cosmic
microwave background (CMB) anisotropy measurements. The results are fully consistent …

We study constraints imposed by two proposed string Swampland criteria on cosmology.
These criteria involve an upper bound on the range traversed by scalar fields as well as a …

CMB-S4 Science Case, Reference Design, and Project Plan Page 1 CMB-S4 Science Case,
Reference Design, and Project Plan CMB-S4 Collaboration July 9, 2019 arXiv:1907.04473v1 …

Axions and other very light axion-like particles appear in many extensions of the Standard
Model, and are leading candidates to compose part or all of the missing matter of the …

Several pulsar timing arrays including NANOGrav, EPTA, PPTA, and CPTA have recently
reported the observation of a stochastic background of gravitational wave spectrum in the …