Collaborative Research: Gravitational Waves as Messengers from the Early Universe

The detection of gravitational waves (GW) has opened a new window for astronomy. GW astronomy holds the potential for helping reconstruct a picture of the universe at energy scales much higher (and at times much earlier) than the picture obtained using the cosmic microwave background (CMB). A research program between Carnegie-Mellon University (CMU) and Massachusetts Institute of Technology (MIT) will use gravity as a tool to understand more about high energy physics and cosmology, as well as numerical simulations of magnetohydrodynamic processes in the early universe. The project also includes a broad range of education and outreach activities. There will be training of graduate and undergraduate students at both CMU and MIT, along with a vigorous public outreach program, including programs with local middle and high schools, an astronomy training unit with local disabled American veterans, a summer Teacher Training Program, and direct community engagement. The investigators will continue to invite visual artists, astrophotographers, videographers, game designers, and writers to share their cultural arts network for the promotion of science. The LIGO/Virgo detection of gravitational waves has ignited interest in the future direction of GW astronomy, including the search for intriguing signals of stochastic backgrounds from early-universe physics. The NANOGrav collaboration announced detection of a stochastic GW background that can be understood as possibly including a signal from the early universe, such as GWs from and shortly after inflation, cosmic strings and domain walls, phase transitions, turbulence and magnetic fields. The detection of such GWs is challenging due to their small amplitudes, the specific range of the characteristic frequencies, and astrophysical foregrounds. The focus of this research is a study of the GWs from turbulent sources possibly presented at (or around) the quantum (QCD) energy scale. The team will evaluate detection prospects of these GWs, with particular interest in modeling parity violating (chiral) sources that might explain matter-antimatter asymmetry in the universe and investigating the range of the QCD epoch cosmological parameters that can be tested through the pulsar timing arrays. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.