Numerical simulations of early Universe sources of gravitational waves

by Alberto Roper Pol (University of Geneva)

Monday 28 Jul 2025, 15:00 → 16:30 Europe/Stockholm

Albano 2: C2207 - Auditorium 4 (80 seats) (Albano Building 2)

Albano Building 2: C2207 - Auditorium 4  

 

zoom link : https://stockholmuniversity.zoom.us/j/67259623527?pwd=bjG5PbKdb4chVtyQsyPS0a3kUTFLYy.1

Meeting ID: 672 5962 3527
 

Fika will be served after the colloquium talk.

 

Abstract: 

Gravitational wave (GW) astronomy is emerging as an exciting new field, offering unprecedented opportunities for breakthroughs in beyond the standard model physics and early Universe cosmology. The key point is to note that early Universe dynamics operates at energies unreachable by any terrestrial means, creating GW backgrounds that redshift down to detectable frequencies today. A detection of any such background can therefore probe energies far above those accessible to particle colliders, shedding light on fundamental physics questions, such as the state of the early Universe, the baryon asymmetry of the Universe, the nature of the dark matter, or whether exotic objects like primordial black holes or cosmic strings exist. Out of the effort to detect GW backgrounds over a wide range of frequencies, a detection program including a large variety of experiments is emerging, including pulsar timing array (PTA) observations, space-based GW detectors (e.g. LISA), or next-generation ground-based detectors (e.g. ET or CE). PTA collaborations have just announced the first evidence for a GW background at nHz frequencies.

Although a signal from supermassive black hole binaries is naturally expected at those frequencies, cosmological backgrounds also represent a viable explanation. In order to demonstrate that a potential detection can only be explained by a cosmological signal, an accurate modelling of the different GW backgrounds from the early Universe is of paramount importance. Early Universe GW sources are inherently characterised by nonlinear dynamics and, hence, their study requires conducting the use of high-performance computing. I will give a biased review on recent advances on the study of nonlinear dynamics of early Universe physics that are required to provide a precise characterization of the resulting GW background from the early Universe.

 

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The colloquium is given as part of the Nordita Program "Numerical Simulations of Early Universe Sources of Gravitational Waves"