The scalar, vector, and tensor modes in gravitational wave turbulence simulations. (15th June 2021)

• Record Type: Journal Article
• Authors: Brandenburg, Axel; Gogoberidze, Grigol; Kahniashvili, Tina; Mandal, Sayan; Pol, Alberto Roper; Shenoy, Nakul
• Is Part Of: Classical and quantum gravity. Volume 38:Number 14(2021)
• Publication Date: 2021-06-15
• Subjects: primordial magnetic fields -- magnetohydrodynamic turbulence -- circular polarization -- primordial gravitational waves; Quantum gravity -- Periodicals; Gravitation -- Periodicals; Relativity (Physics) -- Periodicals; Space and time -- Periodicals; Periodicals; 521.1
• DOI: 10.1088/1361-6382/ac011c
• Languages: English
• ISSNs: 0264-9381

Abstract

Abstract: We study the gravitational wave (GW) signal sourced by primordial turbulence that is assumed to be present at cosmological phase transitions like the electroweak and quantum chromodynamics phase transitions. We consider various models of primordial turbulence, such as those with and without helicity, purely hydrodynamical turbulence induced by fluid motions, and magnetohydrodynamic turbulence whose energy can be dominated either by kinetic or magnetic energy, depending on the nature of the turbulence. We also study circularly polarized GWs generated by parity violating sources such as helical turbulence. Our ultimate goal is to determine the efficiency of GW production through different classes of turbulence. We find that the GW energy and strain tend to be large for acoustic or irrotational turbulence, even though its tensor mode amplitude is relatively small at most wave numbers. Only at very small wave numbers is the spectral tensor mode significant, which might explain the efficient GW production in that case.