22 problems

Let the moduli space of an effective theory be equipped with its field-space metric, and consider a point at infinite geodesic distance. Swampland Distance Conjecture. For a viable…

A non-supersymmetric anti-de Sitter solution is a solution with negative cosmological constant that does not preserve supersymmetry. Ooguri–Vafa conjecture. Any non-supersymmetric…

Swampland Cobordism Conjecture. The bordism groups of quantum gravity are trivial:

Let a consistent low-energy effective theory coupled to gravity have a moduli space of theories, and consider an infinite-distance limit in that moduli space. Distance Conjecture.…

String theory constructions have had difficulty producing a de Sitter background compatible with a complete higher-dimensional theory. De Sitter conjecture. Such a background canno…

De Sitter swampland conjecture. There is an order-one constant $\gamma$ such that

Let $d\geq 3$, and consider solutions of quantum gravity in $d$ spacetime dimensions. A cosmological event horizon is the horizon associated with the finite distance traveled by li…

A global symmetry is a symmetry that is not gauged and is not spontaneously broken. A UV-complete theory of quantum gravity is a theory incorporating quantum gravity that remains w…

Let $\mathcal{M}$ be the moduli space of an effective field theory, and let $P,O\in\mathcal{M}$ be points such that $O$ is approached from $P$ along a shortest geodesic with…

Let $\Phi=(\phi^1,\dots,\phi^N)$ be fields in a low-energy effective field theory coupled to dynamical $D$-dimensional spacetime, with vacuum state $|\Omega\rangle$. Let…

Consider a one-parameter family of $D$-dimensional Anti-de Sitter metrics $g_{\mu\nu}(\Lambda)$ arising as quantum-gravity low-energy effective theories, labelled by their cosmolog…

Let $\Phi=(\phi^1,\dots,\phi^N)$ be scalar fields with potential $V(\Phi)$ in a low-energy effective field theory coupled to dynamical $D$-dimensional spacetime. Let $\nabla_i$ den…

Let $c9$ be a tangential structure, and suppose a consistent $n$-dimensional theory of quantum gravity sums over spacetime backgrounds carrying a $c9$-structure. The associated bor…

Swampland distance conjecture. An infinite tower of states becomes exponentially light when moving an infinite distance in the moduli space. More intuitively, an infinite-distance…

A massive spin-two field is denoted by $w_{\mu\nu}$, with mass $m$. Let $M_w$ be the scale associated with the interactions of $w_{\mu\nu}$, and let $M_{\mathrm{Pl}}$ denote the Pl…

Weak gravity conjecture. Such a theory should always contain a stable superextremal particle; equivalently, there should exist a stable particle of mass $m$ and electric charge $q$…

A complete theory of quantum gravity is expected not to admit any global symmetries. Global symmetry conjecture. A complete theory of quantum gravity cannot exhibit any global symm…

Let $\mathcal{C}$ be the Coulomb branch consisting of scalar moduli $\phi^I$ at which all BPS particles have non-negative mass squared. Mass–tension conjecture. If all BPS particle…

The relevant monopole strings are supergravity strings whose infrared worldsheet theory has $(0,8)$ supersymmetry. Kim–Lee–Park's conjecture. Such strings have central charges … an…

Weak gravity conjecture. All forces must be either stronger than gravity, or vanish.

Let an effective theory of quantum gravity be described in a region of field space, and consider moving sufficiently far in that field space. A tower of states is a collection of s…

A consistent six-dimensional ${\cal N}=1$ supergravity theory is a low-energy theory subject to anomaly-cancellation and other quantum-consistency constraints, and a string-theory…