# Constraints on axion inflation from the weak gravity conjecture

## Abstract

We derive constraints facing models of axion inflation based on decay constant alignment from a string-theoretic and quantum gravitational perspective. In particular, we investigate the prospects for alignment and ‘anti-alignment’ of C{sub 4} axion decay constants in type IIB string theory, deriving a strict no-go result in the latter case. We discuss the relationship of axion decay constants to the weak gravity conjecture and demonstrate agreement between our string-theoretic constraints and those coming from the ‘generalized’ weak gravity conjecture. Finally, we consider a particular model of decay constant alignment in which the potential of C{sub 4} axions in type IIB compactifications on a Calabi-Yau three-fold is dominated by contributions from D7-branes, pointing out that this model evades some of the challenges derived earlier in our paper but is highly constrained by other geometric considerations.

- Authors:

- Jefferson Physical Laboratory, Harvard University,Cambridge, MA 02138 (United States)

- Publication Date:

- Sponsoring Org.:
- SCOAP3, CERN, Geneva (Switzerland)

- OSTI Identifier:
- 22458373

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 09; Other Information: PUBLISHER-ID: JCAP09(2015)020; OAI: oai:repo.scoap3.org:11742; Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ALIGNMENT; AXIONS; COSMOLOGICAL INFLATION; COSMOLOGY; LIMITING VALUES; QUANTUM GRAVITY; STRING THEORY

### Citation Formats

```
Rudelius, Tom.
```*Constraints on axion inflation from the weak gravity conjecture*. United States: N. p., 2015.
Web. doi:10.1088/1475-7516/2015/09/020.

```
Rudelius, Tom.
```*Constraints on axion inflation from the weak gravity conjecture*. United States. doi:10.1088/1475-7516/2015/09/020.

```
Rudelius, Tom. Tue .
"Constraints on axion inflation from the weak gravity conjecture". United States.
doi:10.1088/1475-7516/2015/09/020.
```

```
@article{osti_22458373,
```

title = {Constraints on axion inflation from the weak gravity conjecture},

author = {Rudelius, Tom},

abstractNote = {We derive constraints facing models of axion inflation based on decay constant alignment from a string-theoretic and quantum gravitational perspective. In particular, we investigate the prospects for alignment and ‘anti-alignment’ of C{sub 4} axion decay constants in type IIB string theory, deriving a strict no-go result in the latter case. We discuss the relationship of axion decay constants to the weak gravity conjecture and demonstrate agreement between our string-theoretic constraints and those coming from the ‘generalized’ weak gravity conjecture. Finally, we consider a particular model of decay constant alignment in which the potential of C{sub 4} axions in type IIB compactifications on a Calabi-Yau three-fold is dominated by contributions from D7-branes, pointing out that this model evades some of the challenges derived earlier in our paper but is highly constrained by other geometric considerations.},

doi = {10.1088/1475-7516/2015/09/020},

journal = {Journal of Cosmology and Astroparticle Physics},

number = 09,

volume = 2015,

place = {United States},

year = {Tue Sep 08 00:00:00 EDT 2015},

month = {Tue Sep 08 00:00:00 EDT 2015}

}