Publications (27)
On Axion Reheating in the String Landscape
James Halverson, Cody Long, Brent Nelson +1
We demonstrate that asymmetric reheating arises in a large ensemble of string compactifications with many axions and gauged dark sectors. This phenomenon may help avoid numerous co…
Small Vacuum Energy and Tunneling in a Modified Bousso-Polchinski Model
James Halverson, Justin Khoury, Cody Long
We propose a simplified model for the cosmological constant in string theory flux vacua motivated by type IIB and F-theory compactifications. Relative to the Bousso-Polchinski mode…
Statistical Predictions in String Theory and Deep Generative Models
James Halverson, Cody Long
Generative models in deep learning allow for sampling probability distributions that approximate data distributions. We propose using generative models for making approximate stati…
On String Theory Expectations for Photon Couplings to Axion-Like Particles
James Halverson, Cody Long, Brent Nelson +1
ALP-photon couplings are modeled in large ensembles of string vacua and random matrix theories. In all cases, the effective coupling increases polynomially in the number of ALPs, o…
Minimal Surfaces and Weak Gravity
Mehmet Demirtas, Cody Long, Liam McAllister +1
We show that the Weak Gravity Conjecture (WGC) implies a nontrivial upper bound on the volumes of the minimal-volume cycles in certain homology classes that admit no calibrated rep…
Planckian Axions in String Theory
Thomas C. Bachlechner, Cody Long, Liam McAllister
We argue that super-Planckian diameters of axion fundamental domains can naturally arise in Calabi-Yau compactifications of string theory. In a theory with axions , the f…
Gravitational Waves from Dark Yang-Mills Sectors
James Halverson, Cody Long, Anindita Maiti +2
Dark Yang-Mills sectors, which are ubiquitous in the string landscape, may be reheated above their critical temperature and subsequently go through a confining first-order phase tr…
Instanton Resummation and the Weak Gravity Conjecture
Ben Heidenreich, Cody Long, Liam McAllister +2
We develop methods for resummation of instanton lattice series. Using these tools, we investigate the consequences of the Weak Gravity Conjecture for large-field axion inflation. W…
The Kreuzer-Skarke Axiverse
Mehmet Demirtas, Cody Long, Liam McAllister +1
We study the topological properties of Calabi-Yau threefold hypersurfaces at large . We obtain two million threefolds by triangulating polytopes from the Kreuzer-Skark…
An Ultralight Axion in Supersymmetry and Strings and Cosmology at Small Scales
James Halverson, Cody Long, Pran Nath
Dynamical mechanisms to generate an ultralight axion of mass eV in supergravity and strings are discussed. An ultralight particle of this mass provides a c…
Systematics of Axion Inflation in Calabi-Yau Hypersurfaces
Cody Long, Liam McAllister, John Stout
We initiate a comprehensive survey of axion inflation in compactifications of type IIB string theory on Calabi-Yau hypersurfaces in toric varieties. For every threefold with $h^{1,…
Heavy Tails in Calabi-Yau Moduli Spaces
Cody Long, Liam McAllister, Paul McGuirk
We study the statistics of the metric on Kähler moduli space in compactifications of string theory on Calabi-Yau hypersurfaces in toric varieties. We find striking hierarchies in…
The Singularity Structure of Scale-Invariant Rank-2 Coulomb Branches
Philip C. Argyres, Cody Long, Mario Martone
We compute the spectrum of scaling dimensions of Coulomb branch operators in 4d rank-2 superconformal field theories. Only a finite rational set of scaling dimens…
Vacuum Selection from Cosmology on Networks of String Geometries
Jonathan Carifio, William J. Cunningham, James Halverson +3
We introduce network science as a framework for studying the string landscape. Two large networks of string geometries are constructed, where nodes are extra-dimensional six-manifo…
D Anomaly-Free Matter Spectrum in F-theory on Singular Spaces
Antonella Grassi, James Halverson, Cody Long +3
In this paper we study the 6d localized charged matter spectrum of F-theory directly on a singular elliptic Calabi-Yau 3-fold, i.e. without smoothing via resolution or deformation…
The Hodge Numbers of Divisors of Calabi-Yau Threefold Hypersurfaces
Andreas P. Braun, Cody Long, Liam McAllister +2
We prove a formula for the Hodge numbers of square-free divisors of Calabi-Yau threefold hypersurfaces in toric varieties. Euclidean branes wrapping divisors affect the vacuum stru…
Non-Holomorphic Cycles and Non-BPS Black Branes
Cody Long, Artan Sheshmani, Cumrun Vafa +1
We study extremal non-BPS black holes and strings arising in M-theory compactifications on Calabi-Yau threefolds, obtained by wrapping M2 branes on non-holomorphic 2-cycles and M5…
PQ Axiverse
Mehmet Demirtas, Naomi Gendler, Cody Long +2
We show that the strong CP problem is solved in a large class of compactifications of string theory. The Peccei-Quinn mechanism solves the strong CP problem if the CP-breaking effe…
Superradiance in String Theory
Viraf M. Mehta, Mehmet Demirtas, Cody Long +3
We perform an extensive analysis of the statistics of axion masses and interactions in compactifications of type IIB string theory, and we show that black hole superradiance exclud…
Aligned Natural Inflation in String Theory
Cody Long, Liam McAllister, Paul McGuirk
We propose a scenario for realizing super-Planckian axion decay constants in Calabi-Yau orientifolds of type IIB string theory, leading to large-field inflation. Our construction i…
On Algorithmic Universality in F-theory Compactifications
James Halverson, Cody Long, Benjamin Sung
We study universality of geometric gauge sectors in the string landscape in the context of F-theory compactifications. A finite time construction algorithm is presented for $\frac4…
Superradiance Exclusions in the Landscape of Type IIB String Theory
Viraf M. Mehta, Mehmet Demirtas, Cody Long +3
We obtain constraints from black hole superradiance in an ensemble of compactifications of type IIB string theory. The constraints require knowing only the axion masses and self-in…
On the Scarcity of Weak Coupling in the String Landscape
James Halverson, Cody Long, Benjamin Sung
We study the geometric requirements on a threefold base for the corresponding F-theory compactification to admit a weakly-coupled type IIB limit. We examine both the standard Sen l…
The Desert and the Swampland
Cody Long, Miguel Montero, Cumrun Vafa +1
The most natural expectation away from asymptotic limits in moduli space of supergravity theories is the desert scenario, where there are few states between massless fields and the…
Non-simply-laced Symmetry Algebras in F-theory on Singular Spaces
Antonella Grassi, James Halverson, Cody Long +2
We demonstrate how non-simply-laced gauge and flavor symmetries arise in F-theory on spaces with non-isolated singularities. The breaking from a simply-laced symmetry to one that i…
Planckian Axions and the Weak Gravity Conjecture
Thomas C. Bachlechner, Cody Long, Liam McAllister
Several recent works have claimed that the Weak Gravity Conjecture (WGC) excludes super-Planckian displacements of axion fields, and hence large-field axion inflation, in the absen…
Constraints on Standard Model Constructions in F-theory
Mirjam Cvetic, James Halverson, Ling Lin +1
We argue that the following three statements cannot all be true: (i) our vacuum is a type IIB / F-theory vacuum at moderate-to-large , (ii) the -expansion is controll…