2015/09/28 by Sachiko Kuroyanagi, Takashi Hiramatsu, Jun’ichi Yokoyama +1 · 12 citations
Physics and Astronomy · #Astrophysics #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Dark energy #Galaxies: Formation, Evolution, Phenomena #Gravitation #Gravitational field #Gravitational redshift #Gravitational wave #Gravitational wave background #Hubble's law #Inflation (cosmology) #Physics #Pulsars and Gravitational Waves Research #Quantum electrodynamics #Scalar (mathematics) #Scalar field #Spectral density #Theoretical physics #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1088/1475-7516/2016/02/023
published in Journal of Cosmology and Astroparticle Physics 2016(02), 023 (Institute of Physics) · 12 pages, 9 figures
arxiv created 2015/09/28 · openalex publication_date 2016/02/09 · arxiv updated 2016/06/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We investigate the imprint of reheating on the gravitational wave spectrum produced by self-ordering of multi-component scalar fields after a global phase transition. The equation of state of the Universe during reheating, which usually has different behaviour from that of a radiation-dominated Universe, affects the evolution of gravitational waves through the Hubble expansion term in the equations of motion. This gives rise to a different power-law behavior of frequency in the gravitational wave spectrum. The reheating history is therefore imprinted in the shape of the spectrum. We perform 512 3 lattice simulations to investigate how the ordering scalar field reacts to the change of the Hubble expansion and how the reheating effect arises in the spectrum. We also compare the result with inflation-produced gravitational waves, which has a similar spectral shape, and discuss whether it is possible to distinguish the origin between inflation and global phase transition by detecting the shape with future direct detection gravitational wave experiments such as DECIGO.