The Swampland: Introduction and Review
read the original abstract
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 to the field, assuming only a knowledge of quantum field theory and general relativity. It also forms a comprehensive review, covering the range of ideas that are part of the field, from the Weak Gravity Conjecture, through compactifications of String Theory, to the de Sitter conjecture.
This paper has not been read by Pith yet.
Forward citations
Cited by 47 Pith papers
-
$\text{AdS}_D\times I$ solutions in axio-dilaton gravity
The authors reformulate the equations of motion for AdS_D × I solutions in axio-dilaton gravity as a first-order autonomous dynamical system, identify fixed points and analytic solutions for arbitrary D including in t...
-
Phase-resolved field-space distance criteria in ekpyrotic, bouncing and cyclic cosmologies
Phase-resolved field-space distance bounds for non-inflationary smoothing yield a master lower bound on ε_ek and imply ultra-fast-roll ekpyrosis or modified bounces to match observed red-tilted perturbations.
-
Phase-resolved field-space distance criteria in ekpyrotic, bouncing and cyclic cosmologies
Phase-resolved scalar distance bounds are derived for ekpyrotic, bouncing, and cyclic cosmologies, yielding a master condition that lower-bounds ε_ek from remaining distance after conversion and bounce.
-
Towards black-hole horizons and geodesic focusing in causal sets
Causal sets can approximate black hole horizons via discrete timelike curves and ladders tracing null geodesics, with a discrete expansion changing sign across the horizon in a 1+1D toy model.
-
Taxonomy of Instanton Corrections in Infinite Distance Limits
The Schwinger integral over light towers captures precisely the instantons with actions in the window (Λ_sp/M_light)^{-1} ≤ S_inst ≤ Λ_sp/M_light, as verified in eight- and seven-dimensional toroidal compactifications.
-
Optimal paths across potentials on scalar field space
Optimal transport yields a generalized Wasserstein distance on field space, obtained from a WKB expansion of a Schrödinger equation and extended to dynamical gravity via the Wheeler-DeWitt equation in the ADM formalism.
-
Alice in Warpland: KK modes, Warped Compactifications and the Swampland
In codimension-one warped compactifications with exponential potentials, the KK mass decay rate λ_KK is reduced by warping but still satisfies the Sharpened Distance Conjecture precisely when the higher-dimensional po...
-
All $2D$ generalised dilaton theories from $d\geq 4$ gravities
Generic 2D Horndeski theories arise from dimensional reduction of d≥4 gravities, yielding a Birkhoff theorem for quasi-topological gravities where static spherically symmetric solutions satisfy g_tt g_rr = -1 and are ...
-
Effective geometrodynamics for renormalization-group improved black-hole spacetimes in spherical symmetry
RG-improved black hole spacetimes with scale-dependent gravitational coupling are derived as vacuum solutions to 2D Horndeski master field equations, embedding prior works and exposing implementation discrepancies.
-
Positivity with Long-Range Interactions
Defines IR-finite amplitudes M_E that preserve analyticity and unitarity to derive positivity bounds on EFTs including electromagnetism and gravity in D=4.
-
An M-theory dS maximum from Casimir energies on Riemann-flat manifolds
Explicit scale-separated dS5 maximum in M-theory on a 6D Riemann-flat manifold with vacuum energy 10^{-8} in Planck units, obtained via Casimir energies and fluxes.
-
Stochastic Survival near Swampland Boundaries
A stochastic survival framework maps swampland control data to conditioned drifts for moduli histories near boundaries via the Doob transform, yielding a universal inward wall response near regular hard boundaries.
-
AdS$_9$ solutions in type II supergravities
New analytic AdS9 solutions in type IIB with finite action and central charge, numerical massive IIA solutions with diverging action, and perturbative dS9 solutions are constructed in type II supergravities.
-
EFTs with Symmetric Moduli Spaces: the Landscape and the Swampland
Using weight polytopes of irreducible representations, a finite list of symmetric moduli spaces satisfies the SDC decay rates; most embed from an E8(8) EFT but three cannot be obtained from string or M-theory compacti...
-
Bordisms between 9d type IIB supergravities and commutator widths of duality groups
Proposes a refinement of the Swampland Cobordism Conjecture for duality groups, arguing that diverging commutator widths necessitate infinitely many duality defects to realize monodromies in 9d supergravity bordisms.
-
Bordisms between 9d type IIB supergravities and commutator widths of duality groups
Proposes a refinement of the Swampland Cobordism Conjecture for Ω1(BG) with duality bundle G, where diverging commutator width of G requires infinitely many duality defects to realize monodromies via gravitational solitons.
-
Phase-resolved field-space distance criteria in ekpyrotic, bouncing and cyclic cosmologies
Proposes phase-resolved invariant path-length criteria and a master formula for lower bound on ε_ek in ekpyrotic cosmologies, using BKL suppression and conversion windows as constraints.
-
Fifth-Force Constraints from UV-Complete Scalar-Tensor Gravity
UV completeness in scalar-tensor gravity restricts the fifth-force Yukawa parameters α and λ to a narrow wedge in parameter space, ruling out its complement and part of the experimentally allowed domain.
-
Fifth-Force Constraints from UV-Complete Scalar-Tensor Gravity
UV completeness in scalar-tensor gravity restricts Yukawa fifth-force parameters α and λ to a finite wedge whose complement is ruled out, with part of the excluded domain below current experimental bounds.
-
Taxonomy of Instanton Corrections in Infinite Distance Limits
The Schwinger integral over light towers captures precisely those instantons with actions in the window (Λ_sp/M_light)^{-1} ≤ S_inst ≤ Λ_sp/M_light.
-
Micron-sized Extra Dimensions and Primordial Black Holes: Charged, Rotating, and Memory Burdened
Six-dimensional primordial black holes with memory burden effects can survive as light dark matter in a two-extra-dimension model at the 10 TeV scale, producing high-multiplicity thermal events at future colliders.
-
Generalised Symmetries and Swampland-Type Constraints from Charge Quantisation via Rational Homotopy Theory
Refining charge quantization via a homotopy type A yields swampland-like constraints ruling out noncompact gauge groups and non-nilpotent one-form Lie algebras, and requires A to be contractible for quantum gravity theories.
-
Generalised Symmetries and Swampland-Type Constraints from Charge Quantisation via Rational Homotopy Theory
Refines charge quantization via homotopy type A whose homotopy groups classify brane charges and homology groups classify higher-form symmetries, deriving swampland-like constraints that rule out noncompact gauge grou...
-
Sampling the Graviton Pole and Deprojecting the Swampland
A sampling-based bootstrap for graviton poles in EFTs yields non-projective bounds that fix the EFT cutoff scale relative to the Planck mass, with M/M_P ≲ 7.8 in D=5.
-
Bounding axion dark energy
An analytic bound on axion parameters in thawing quintessence is derived independently of initial conditions and used with cosmological observations plus quantum gravity constraints to exclude large regions of axion d...
-
5D Rotating Black Holes as dark matter in Dark Dimension Scenario: Hawking Radiation versus the Memory Burden Effect
Five-dimensional rotating primordial black holes with initial masses above 10^10 grams survive to today and can account for all dark matter due to suppressed Hawking radiation and memory burden effects in the micron-s...
-
Towards theory constraints on ultralight dark matter from quantum gravity
In asymptotically safe gravity, dimension-five couplings of ultralight scalar dark matter to gauge field strengths vanish and are not generated perturbatively.
-
Morse-Bott inequalities, Topology Change and Cobordisms to Nothing
Morse-Bott inequalities yield homology bounds and topology-change counts for generic cobordisms to nothing in string theory compactifications.
-
ISCOs and the weak gravity conjecture bound in higher derivative theories of gravity
Derives WGC bound on probe charge-to-mass ratio from positivity of anomalous dimensions in dual CFT for charged particles in higher-derivative AdS black holes, with bound increasing with couplings and ISCOs existing u...
-
Supersymmetry, Large Extra Dimensions and the Gravitino Conjecture
Under the Gravitino Conjecture, only one or two large extra dimensions are compatible with a linear scaling between gravitino mass and KK scale in Type II compactifications, implying light gravitino and gauge-mediated...
-
Sharpening the Supersymmetric Axion Weak Gravity Conjecture
The paper verifies the bound fS/|n| ≤ (π/(2 κ_d)) sqrt((d-1)/(d-2)) for axion instantons and sharpens it to fS/|n| ≤ (1/κ_4) sqrt(7/2) for supersymmetric 4d instantons using three approaches in the string landscape.
-
Towards the Realization of the Dark Dimension Scenario in Ho\v{r}ava-Witten Theory
Hořava-Witten theory offers a potential string embedding of the dark dimension by localizing the Standard Model on the 11th interval, with symmetric tadpole cancellation and an infinite-distance limit helping derive t...
-
Double fibration in G-theory and the cobordism conjecture
In G-theory motivated Type IIB compactifications with varying fields, End of the World branes trivialize a cohomology class and additional non-perturbative objects are required to cancel the bordism group while retain...
-
Some Properties and Uses of the Species Scale
The Species Scale implies Laplace eigenvalue equations for BPS-protected Wilson coefficients and produces a one-loop moduli potential with minima at desert points that may stabilize Kähler moduli in 4d Type IIB orientifolds.
-
Bounds on Discrete Gauge Symmetries in Supergravity
Upper bounds are placed on the order of enhanced discrete gauge symmetries in supersymmetric supergravity theories with 8 or more supercharges, with some bounds saturated by string theory examples.
-
Non-invertible symmetries in the axiverse, and the imaginary wormholes
Identifies invertible and non-invertible generalized symmetries in axiverse EFTs and argues that wormholes break non-invertible axion symmetries via the Imaginary Distance Bound, implying a distinguished role for towe...
-
Micron-sized Extra Dimensions and Primordial Black Holes: Charged, Rotating, and Memory Burdened
In a six-dimensional theory with micron-sized extra dimensions, memory-burdened primordial black holes can survive as dark matter down to sub-gram masses while producing detectable high-multiplicity events at future c...
-
Barrow holographic dark energy interacting model in the presence of radiation and matter
Numerical study of interacting Barrow holographic dark energy in non-flat universes with radiation, showing EoS transitions and higher fitted H0 values that may address Hubble tension.
-
Assisted Fibre Inflation in Perturbative LVS
Multi-field fibre inflation in perturbative LVS uses collective dynamics of several moduli to achieve viable cosmology with sub-Planckian individual field ranges given by total range divided by sqrt(n).
-
The weak gravity conjecture in perturbative strings
A summary of a proposed proof that the Weak Gravity Conjecture follows from the structure of perturbative bosonic string theory.
-
Rethinking quantum information in gravity and fields
The paper organizes important open questions in quantum gravity and quantum information into four themes without presenting new results or derivations.
-
What to do with a Ricci-flat Calabi--Yau metric?
A roadmap paper describing potential applications of numerical Ricci-flat Calabi-Yau metrics to heterotic string phenomenology and mathematical questions in special geometry.
-
Breaking Free from the Swampland of Impossible Universes through the DESI Portal
A review summarizing advancements over the past two years that link DESI baryon acoustic oscillation data to string-inspired scenarios with dynamic dark energy.
-
Breaking Free from the Swampland of Impossible Universes through the DESI Portal
DESI data indicating evolving dark energy may allow string theory to describe observed universes without violating swampland constraints on constant dark energy.
-
Dark energy from string theory: an introductory review
String theory imposes constraints on dark energy but permits various construction attempts for de Sitter vacua and single-field exponential quintessence models despite obstructions.
-
On Legacy of Starobinsky Inflation
A memorial review of the Starobinsky inflation model that proposes a deformation for primordial black hole production and discusses superstring quantum corrections plus universal reheating.
-
ICTP Lectures on (Non-)Invertible Generalized Symmetries
Lecture notes explain non-invertible generalized symmetries in QFTs as topological defects arising from stacking with TQFTs and gauging diagonal symmetries, plus their action on charges and the SymTFT framework.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.