Speaker
Description
Scalar-induced gravitational waves (SIGWs) are ubiquitous in many early-Universe processes accompanied by non-Gaussianity; hence, precise calculations of SIGWs involve a full understanding
of non-Gaussianity. Therefore, we propose to use the lattice simulations to directly calculate
the energy density spectra of SIGWs with non-Gaussianity up to all orders. Our proposal has been
first verified to match the existing semi-analytical results with non-Gaussianity, and then applied to
more general cases, including high-order primordial non-Gaussianities, the logarithmic dependence
in curvature perturbations, the curvaton model, and the ultra slow-roll model. We find that even a
modest non-Gaussianity can significantly alter ultraviolet behaviors in SIGW spectra, necessitating
special cautions in future detections as well as mutual constraints on/from primordial black holes.
