Lattice simulations of axion-U(1) inflation: gravitational waves, magnetic fields, and scalar statistics

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F25%3A00636833" target="_blank" >RIV/68378271:_____/25:00636833 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0374425" target="_blank" >https://hdl.handle.net/11104/0374425</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1475-7516/2025/05/079" target="_blank" >10.1088/1475-7516/2025/05/079</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Lattice simulations of axion-U(1) inflation: gravitational waves, magnetic fields, and scalar statistics

Popis výsledku v původním jazyce

We numerically study axion-U(1) inflation, focusing on the regime where the coupling between axions and gauge fields results in significant backreaction from the amplified gauge fields during inflation. These amplified gauge fields not only generate high-frequency gravitational waves (GWs), but also enhance spatial inhomogeneities in the axion field. GWs serve as key probe for constraining the coupling strength between the axion and gauge fields. We find that, when backreaction is important during inflation, the constraints on the coupling strength due to GW overproduction are relaxed compared to previous studies, in which backreaction matters only after inflation. Moreover, our results suggest that the probability density function (PDF) of axion fluctuations tends toward a Gaussian distribution even in cases where gauge field backreaction is important only after inflation. This aligns with previous studies where the same effect was observed for cases with strong backreaction during inflation. This finding can be crucial for future studies of primordial black hole (PBH) formation, which can further constrain the coupling strength. We also calculate the spectrum of the produced magnetic fields in this model and find that their strength is compatible with the observed lower limits.

Název v anglickém jazyce

Lattice simulations of axion-U(1) inflation: gravitational waves, magnetic fields, and scalar statistics

Popis výsledku anglicky

We numerically study axion-U(1) inflation, focusing on the regime where the coupling between axions and gauge fields results in significant backreaction from the amplified gauge fields during inflation. These amplified gauge fields not only generate high-frequency gravitational waves (GWs), but also enhance spatial inhomogeneities in the axion field. GWs serve as key probe for constraining the coupling strength between the axion and gauge fields. We find that, when backreaction is important during inflation, the constraints on the coupling strength due to GW overproduction are relaxed compared to previous studies, in which backreaction matters only after inflation. Moreover, our results suggest that the probability density function (PDF) of axion fluctuations tends toward a Gaussian distribution even in cases where gauge field backreaction is important only after inflation. This aligns with previous studies where the same effect was observed for cases with strong backreaction during inflation. This finding can be crucial for future studies of primordial black hole (PBH) formation, which can further constrain the coupling strength. We also calculate the spectrum of the produced magnetic fields in this model and find that their strength is compatible with the observed lower limits.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10303 - Particles and field physics

Projekt

<a href="/cs/project/GA24-13079S" target="_blank" >GA24-13079S: Druhá strana Axions</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Cosmology and Astroparticle Physics

ISSN

1475-7516

e-ISSN

1475-7516

Svazek periodika

2025

Číslo periodika v rámci svazku

5

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

37

Strana od-do

079

Kód UT WoS článku

001502086500005

EID výsledku v databázi Scopus

2-s2.0-105005857873