Gravitational waves from a holographic phase transition

We investigate first order phase transitions in a holographic setting of five-dimensional Einstein gravity coupled to a scalar field, constructing phase diagrams of the dual field theory at finite temperature. We scan over the two-dimensional parameter space of a simple bottom-up model and map out important quantities for the phase transition: the region where first order phase transitions take place; the latent heat, the transition strength parameter alpha, and the stiffness. We find that alpha is generically in the range 0.1 to 0.3, and is strongly correlated with the stiffness (the square of the sound speed in a barotropic fluid). Using the LISA Cosmology Working Group gravitational wave power spectrum model corrected for kinetic energy suppression at large alpha and non-conformal stiffness, we outline the observational prospects at the future space-based detectors LISA and TianQin. A TeV-scale hidden sector with a phase transition described by the model could be observable at both detectors.

Automated summary

Investigating first order phase transitions in a holographic setting, we explore the parameter space and physical quantities, finding a strong correlation between alpha and stiffness. We propose the potential observation of a TeV-scale hidden sector at future space-based detectors using a corrected gravitational wave power spectrum model.