BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Tina Kahniashvili (Carnegie Mellon University) DTSTART:20201104T170000Z DTEND:20201104T180000Z DTSTAMP:20260423T023939Z UID:CMU-TP/18 DESCRIPTION:Title: Circular polarization of gravitational waves from the early-universe turbu lent sources\nby Tina Kahniashvili (Carnegie Mellon University) as par t of Carnegie Mellon theoretical physics\n\n\nAbstract\nI will present dir ect numerical simulations to compute the net circular polarization of grav itational waves from helical (chiral) turbulent sources in the early unive rse for a variety of initial conditions. I will discuss the resulting grav itational wave signal assuming different turbulence genesis such as magne tically or kinetically dominant cases. Under realistic physical conditions in the early universe we have computed numerically for the first time the total (integrated over all wavenumbers) polarization degree of the gravit ational waves and its spectral distribution. Our major finding consists of the spectral polarization degree that strongly depends on the initial con ditions. The peak of the spectral polarization degree occurs (in the waven umber space) at twice the typical wavenumber \nof the source\, as expected \, and for the fully helical decaying turbulence\, reaches its maximum (10 0\\%) only at the peak. In addition\, we have determined the temporal evol ution of the turbulent sources as well as the resulting gravitational wave s\, showing that the dominant contribution to the spectral energy density happens shortly after the source activation and through artificially prolo nged (slow decay) turbulence the increase of the gravitational wave amplit ude at low frequencies can be achieved. Finally\, I will address the detec tion prospects for the net polarization arguing that its detection contain s clean information (including the generation mechanisms\, time\, and stre ngth) about the sources of possible parity violations in the early univers e.\n LOCATION:https://researchseminars.org/talk/CMU-TP/18/ END:VEVENT END:VCALENDAR