### Conveners

#### Parallel: Gravitational Wave 1

- William DeRocco (University of California, Santa Cruz)

It has been investigated to what extend one can constrain inflaton couplings to matter adopting future gravitational wave detectors. Various possible inflaton interactions have been considered. It turned out that in certain cases the proposed gravitational detector facilities would be sensitive the strength of the inflaton-matter couplings.

We initiate a study of the gravitational wave signatures of a phase transition that occurs as the Universe's temperature increases during reheating. The gravitational wave signatures of a heating phase transition are different from those of a cooling phase transition and observation of them would allow us to probe reheating. In the lucky case that the gravitational wave signatures from both...

Axion(-like fields) can explain the cosmological dark matter (DM) abundance and /or the baryon asymmetry of the Universe (BAU). In particular, the axion rotation dynamics, a la the Affleck-Dine mechanism, open up new mechanisms for production of DM and BAU. When the axion rotation energy density dominates the energy density of the universe, a transient matter-dominated (MD) era and a...

We discuss the stochastic gravitational wave background emitted from a network of 'quasi-stable' strings and its realization in grand unified theories. A symmetry breaking in the early universe produces monopoles that suffer partial inflation. A subsequent symmetry breaking at a lower energy scale creates cosmic strings which are effectively stable against the breaking via Schwinger...

Gravitational waves (GW) radiated by compact binary coalescences can be diffracted by astrophysical-size objects due to long wavelengths. This is so-called diffractive lensing. The length scale of the diffraction is determined by the geometric mean of GW wavelength and the effective distance to the lens, and it becomes O(1 pc) assuming GW frequency ~ 1Hz and the distance to lens ~ 1 Gpc....

Particle models beyond the Standard Model are often accompanied by the spontaneous breaking of a new symmetry and thus by a phase transition. Arguably, the most interesting among them are first order phase transitions, in which bubbles of the low-temperature phase form and collide, leading to the generation of gravitational waves (GWs). These might be measurable as stochastic GW background...

We study possible ways gravitational waves (GW) get sourced in a theory with minimal left-right symmetry breaking. First order phase transitions (FOPT) generically lead to gravitational waves sourced by bubble collisions, while second order phase transitions (SOPT) do not. Interesting variants on the standard classification of phase transitions occur due to the breaking of discrete parity...