1–5 Jun 2026
Paraninfo, University of Zaragoza
Europe/Madrid timezone

The spectrum of axions in a scaling string network

1 Jun 2026, 17:50
20m
Pedro Cerbuna

Pedro Cerbuna

Oral presentation Cosmology DM Parallel Session - Cosmology

Speaker

José Ricardo Correia (University of Oslo / Institute of Astrophysics)

Description

A promising dark matter candidate, which arises from a proposed solution to the strong CP problem is the pseudo scalar axion. If the PQ symmetry is broken after inflation, a network of cosmic strings forms and emits axions until the QCD phase transition, where a hybrid string-wall system forms and collapses. Characterizing both the evolution of the network and the emission of axions by the tangle of strings is crucial for obtaining precise axion mass estimates. Following our previous work where we obtain evidence of standard scaling of axion strings (number of string lengths per Hubble patch asymptotes to a constant), we will present new results from our $12288^3$ simulations, along with new cleaner observables of the axion spectrum, and a novel modeling framework. Consistent with the picture of standard scaling, we observe the emergence of a self-similar axion spectrum, with a form in broad agreement with scale invariant emission by strings.

Main Contribution topic Axion / Sterile
Secondary contribution topic Cosmology Dark Matter

Authors

Dr Asier Lopez-Eiguren (University of Basque Country) Dr Joanes Lizarraga (University of Basque Country) Prof. Jon Urrestilla (University of the Basque Country) José Ricardo Correia (University of Oslo / Institute of Astrophysics) Prof. Kari Rummukainen (University of Helsinki) Prof. Mark Hindmarsh (University of Helsinki)

Presentation materials