Hybrid talk: https://stockholmuniversity.zoom.us/j/530682073
+ a room TBA, likely on floor 4 of Hus3 at the Albano campus
Gravitational waves (GWs) may be sourced by hydrodynamic and hydromagnetic turbulent sources in the early universe. I will discuss the results of numerical simulations of GWs from the quantum chromodynamic (QCD) scale induced by various models of primordial turbulence and show that the efficiency of GW production and the GW energy spectra depend strongly on the nature of the turbulence. Additionally, I will revisit big bang nucleosynthesis (BBN) upper limits on the relativistic energy density in the early universe to properly account for the decaying nature of turbulent sources. This allows larger estimates of the initial strength of primordial magnetic fields and/or turbulent motions in the early universe and thus a more powerful source for resulting relic GW signals with more optimistic prospects for detection. I will address the prospects of detecting these GW signals from the QCD scale through pulsar timing arrays and astrometric missions. In particular, I will discuss the potential of explaining the recent NANOGrav evidence for a stochastic GW background with turbulence at the QCD scale and the constraints this observation could place on the properties of such turbulence.