Speaker
Jinn-Ouk Gong
Description
We argue that the coordinate redefinition necessarily introduces inevitable couplings between long- and short-wavelength modes. This leads to a unique footprint of the long-mode gravitational waves in the local scalar power spectrum. We discuss the observational prospects via the quadrupole moment of the local scalar power spectrum. Future Lyman-alpha and 21cm surveys are capable of detecting the quadrupole moment, confirming the long-mode gravitational waves.