Subtracting compact binary foreground sources to reveal primordial gravitational-wave backgrounds

Understand

Detection of primordial gravitational-wave backgrounds generated during the early universe phase transitions is a key science goal for future ground-based detectors.

• The rate of compact binary mergers is so large that their cosmological population produces a confusion background that could masquerade the detection of potential primordial stochastic backgrounds.
• In this paper we study the ability of current and future detectors to resolve the confusion background to reveal interesting primordial backgrounds.
• The current detector network of LIGO and Virgo and the upcoming KAGRA and LIGO-India will not be able to resolve the cosmological compact binary source population and its sensitivity to stochastic background will be limited by the confusion background of these sources.