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 …

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 …

Ultralight axions (ULAs) with masses in the range 1 0-33 eV≤ ma≤ 1 0-20 eV are motivated
by string theory and might contribute to either the dark-matter or dark-energy densities of the …

A bstract Flux couplings to string theory axions yield super-Planckian field ranges along
which the axion potential energy grows. At the same time, other aspects of the physics …

A bstract In this note we show that models of natural inflation based on closed string axions
are incompatible with the weak gravity conjecture (WGC). Specifically, we use T-duality in …

We derive constraints facing models of axion inflation based on decay constant alignment
from a string-theoretic and quantum gravitational perspective. In particular, we investigate …

A bstract We discuss quantum gravitational effects in Einstein theory coupled to periodic
axion scalars to analyze the viability of several proposals to achieve superplanckian axion …

A bstract String theory has been claimed to give rise to natural fuzzy dark matter candidates
in the form of ultralight axions. In this paper we revisit this claim by a detailed study of how …

A bstract String theory axions are interesting candidates for fields whose potential might be
controllable over super-Planckian field ranges and therefore as possible candidates for …