- The paper details DECIGO's innovative space interferometer design and B-DECIGO's role as a precursor for high-precision gravitational wave detection.
- It describes a strategic configuration using 1,000 km and 100 km Fabry-Perot Michelson interferometers, optimized for a 0.1-10 Hz frequency band.
- It emphasizes potential breakthroughs in cosmology, including detecting primordial gravitational waves and improving binary coalescence predictions.
DECIGO and B-DECIGO: Advancing Gravitational Wave Astronomy
The paper discusses the Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO), a future Japanese space mission designed to detect gravitational waves in the frequency band of 0.1 Hz to 10 Hz. The DECIGO mission aims for significant advancements in gravitational wave astronomy, focusing primarily on the detection of primordial gravitational waves potentially generated during the inflationary epoch of the universe. The mission is anticipated to offer comprehensive insights into other phenomena, including the universe's accelerated expansion and high-precision predictions of neutron star and black hole binary coalescences.
Design and Technical Architecture
DECIGO comprises four clusters of observatories, positioned at strategic locations in heliocentric orbit to optimize sensitivity and angular resolution. Each cluster forms an equilateral triangular configuration of three spacecraft, each with a Fabry-Perot Michelson interferometer possessing a 1,000 km arm length. This design facilitates the measurement of gravitational waves by observing minute changes in the distance between freely floating mirror masses. The system leverages a drag-free operation to counteract non-gravitational forces, thereby improving the accuracy of gravitational wave detection.
The choice of the 0.1 Hz to 10 Hz frequency band strategically positions DECIGO to bridge the detection gap between the European Space Agency's LISA project and ground-based detectors like LIGO, Virgo, and KAGRA. DECIGO aims to capture signals from black hole binaries, neutron star binaries, and potentially, primordial gravitational waves, the latter of which are especially prominent around the 0.1 Hz mark.
Objectives and Scientific Implications
DECIGO's primary scientific objective is to detect primordial gravitational waves, which offer critical evidence regarding the universe's inflationary phase. This capability could significantly inform cosmological models and the historical physics of the early universe, potentially delineating details about the inflation scale and reheating temperatures. DECIGO is also poised to make direct measurements of the universe's accelerated expansion using gravitational wave phase and amplitude data, laying foundational insights for dark energy research.
Furthermore, DECIGO is expected to deliver high-fidelity predictions of neutron star and black hole binary coalescences, enhancing multi-messenger astronomy by enabling accurate temporal and locational predictions. The mission's profound sensitivity promises to refine tests of general relativity and may afford a greater understanding of massive black hole genesis in galactic centers.
B-DECIGO: The Precursor Pathfinder
Before launching DECIGO, the team plans to deploy B-DECIGO, a pathfinder mission aimed at demonstrating necessary technologies and initiating scientific exploration. B-DECIGO will utilize a similar spacecraft configuration albeit with a reduced arm length of 100 km. This precursor mission will focus on astrophysical objectives and technology verifications essential for DECIGO's success.
B-DECIGO is designed to predict neutron star binary coalescences with a high degree of angular and temporal accuracy, offering considerable contributions to multi-messenger astronomy. Simultaneously, B-DECIGO will validate foreground clean-up processes critical for isolating primordial gravitational wave signals from the myriad of astrophysical sources, a capability crucial for the success of the full-scale DECIGO mission.
Future Prospects and Timeline
The comprehensive plan outlines the launch of B-DECIGO in the 2030s, with DECIGO to follow upon incorporating operational insights gained from the pathfinder mission. Preliminary technology demonstration missions are anticipated in the late 2020s, focusing on Fabry-Perot cavity operation and drag-free systems integration. Execution of these plans promises to extend the boundaries of gravitational wave astronomy, enabling unprecedented exploration of the universe's origins and dynamics.
In conclusion, the implementation of DECIGO and B-DECIGO is positioned to profoundly enhance our understanding of gravitational wave phenomena and the universe's formative processes, integrating advanced technology with strategic scientific objectives to further gravitational wave astronomy in the coming decades.
