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 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 …

It has been notoriously difficult to construct a meta-stable de Sitter (dS) vacuum in string
theory in a controlled approximation. This suggests the possibility that meta-stable dS …

We present a brief overview of attempts to construct de Sitter vacua in string theory and
explain how the results of this 20-year endeavor could point to the fact that string theory …

De Sitter solutions have been recently conjectured to be incompatible with quantum gravity.
In this paper we critically assess the progress and challenges of different mechanisms to …

We review the advanced version of the KKLT construction and pure de Sitter supergravity,
involving a nilpotent multiplet, with regard to various conjectures that de Sitter state cannot …

We give an overview of moduli stabilization in compactifications of string theory. We
summarize current methods for construction and analysis of vacua with stabilized moduli …

According to a conjecture recently put forward in, the scalar potential V of any consistent
theory of quantum gravity satisfies a bound|∇ V|/V≥ O (1). This forbids de Sitter solutions …

We provide a detailed discussion of the main theoretical and phenomenological challenges
of quintessence model building in any numerically controlled regime of the moduli space of …

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 …