On the Geometry of the String Landscape and the Swampland

By Hirosi Ooguri, C. Vafa. 2006

1,217 citations recorded by the source corpus.

We make a number of conjectures about the geometry of continuous moduli parameterizing the string landscape. In particular we conjecture that such moduli are always given by expectation value of scalar fields and that moduli spaces with finite non-zero diameter belong to the swampland. We also conjecture that points at infinity in a moduli space correspond to points where an infinite tower of massless states appear, and that near these regions the moduli space is negatively curved. We also propose that there is no non-trivial 1-cycle of minimum length in the moduli space. This leads in particular to the prediction of the existence of a radially massive partner to the axion. These conjectures put strong constraints on inflaton potentials that can appear in a consistent quantum theory of gravity. Our conjectures are supported by a number of highly non-trivial examples from string theory. Moreover it is shown that these conditions can be violated if gravity is decoupled.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/aeae55ddc1164f0ca6ca53542d41d88407a59a20

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Eran Palti
2. Gary Shiu
3. Tom Rudelius
4. Liam McAllister
5. M. Graña
6. C. Vafa
7. Pablo Soler
8. Michael J. Reece

In Nuclear and High Energy Physics

1. Eran Palti
2. Tom Rudelius
3. C. Vafa
4. Gary Shiu
5. T. Weigand
6. Washington Taylor
7. M. Graña
8. Liam McAllister

Citations in the corpus

• On the possibility of large axion moduli spaces (2014, background): “In [31, 32], it was pointed out that not all consistent low-energy effective theories admit consistent ultraviolet completions in string theory, and the sizeable collection of theories with-”
• A stringy test of the Scalar Weak Gravity Conjecture (2018, methodology): “According to the Swampland Distance Conjecture [5], a tower of states becomes massless whenever a point at infinite distance is approached, and the mass is conjectured to decrease exponentially in the distance in moduli space.”
• Assessing observational constraints on dark energy (2024, methodology): “We note that for each model considered in this work, the Swampland conjectures [18, 21, 22] (thought to be required for a consistent theory of quantum gravity) are satisfied for a substantial range of parameters.”
• Global aspects of the space of 6D N = 1 supergravities (2010, background): “lying in the “swampland” [38] consisting of theories which cannot be ruled out from lowenergy considerations and yet which cannot be realized in string theory.”
• Higher-order corrections to mass-charge relation of extremal black holes (2006, neutral): “Keywords: Black Holes in String Theory, Superstring Vacua, Black Holes. c© SISSA 2007 http://jhep.sissa.it/archive/papers/jhep122007068/jhep122007068.pdf J H E P 1 2 ( 2 0 0 7 ) 0 6 8 Contents”
• The weak gravity conjecture and scalar fields (2017, background): “The conjecture is based on an earlier weaker statement in [27] about infinite distances in moduli space which we term the Swampland Conjecture, and is supported primarily by evidence from string theory [25,27–29].”
• Effect of curvature squared corrections in AdS on the viscosity of the dual gauge theory (2007, background): “For example, it is known that many classes of low-energy effective field theories are inconsistent with string theory (and some are inconsistent with any theory of quantum gravity) [20, 21, 22, 23, 24].”
• The powers of monodromy (2014, background): “These latter sectors are the closest the system comes to the emergence of light states at large field [68], albeit not via an approach to a weak-coupling or large-radius limit of moduli space.”
• Weak gravity strongly constrains large-field axion inflation (2015, background): “Still, it is thought that noncompact fields in string theory are highly constrained, and that effective field theory always breaks down in the presence of super-Planckian field ranges [38, 40, 41].”
• Sharpening the weak gravity conjecture with dimensional reduction (2015, background): “Low-energy field theories that cannot be completed into gravitational theories are said to reside in the “Swampland,” and a few heuristic criteria for determining that a theory is in the Swampland have been proposed [1–3].”
• Evidence for a sublattice weak gravity conjecture (2016, background): “Theories that cannot be consistently completed into gravitational theories are said to reside in the “Swampland” [1, 2].”