Gravitational-wave physics with Cosmic Explorer: limits to low-frequency sensitivity

TL;DR

Cosmic Explorer aims to be a next-generation gravitational-wave observatory capable of detecting signals from the early universe, with sensitivity below 10 Hz limited by various noise sources, requiring advanced technologies.

Contribution

This work analyzes multiple noise sources affecting Cosmic Explorer's low-frequency sensitivity and outlines technological requirements to achieve the target strain sensitivity.

Findings

Strain sensitivity better than 10^{-23}/Hz^{1/2} down to 5 Hz is achievable with improved technologies.

Identifies key noise sources and necessary mitigation strategies for low-frequency gravitational-wave detection.

Refines previous Cosmic Explorer designs and outlines future research directions.

Abstract

Cosmic Explorer (CE) is a next-generation ground-based gravitational-wave observatory concept, envisioned to begin operation in the 2030s, and expected to be capable of observing binary neutron star and black hole mergers back to the time of the first stars. Cosmic Explorer's sensitive band will extend below 10 Hz, where the design is predominantly limited by geophysical, thermal, and quantum noises. In this work, thermal, seismic, gravity-gradient, quantum, residual gas, scattered-light, and servo-control noises are analyzed in order to motivate facility and vacuum system design requirements, potential test mass suspensions, Newtonian noise reduction strategies, improved inertial sensors, and cryogenic control requirements. Our analysis shows that with improved technologies, Cosmic Explorer can deliver a strain sensitivity better than $10^{-23}/\mathrm{Hz}^{1/2}$ down to 5 Hz. Our work refines and extends previous analysis of the Cosmic Explorer concept and outlines the key research areas needed to make this observatory a reality.