The LIGO group at the University of Birmingham is building and testing new sensors and coatings to make the gravitational-wave detectors more sensitive. Why this matters: Gravitational waves are ripples in spacetime caused by violent cosmic events like black hole mergers. Current detectors can only see the most extreme collisions. To detect fainter, more distant events—and to see new types of sources like neutron star-black hole binaries—the instruments need to be quieter and more stable. The group is working on three technical bottlenecks: improving vibration isolation at low frequencies, reducing thermal noise in the mirror coatings that sets the peak sensitivity, and developing more accurate theoretical models of the gravitational wave signals. Potential impact: This is fundamental science with no immediate practical application. The goal is to observe more of the universe—hundreds of black hole mergers, neutron star-black hole binaries, and possibly entirely new phenomena. Deeper understanding of gravity, the equation of state of matter at extreme densities, and the astrophysical origins of compact binaries could emerge. Past fundamental research on gravitational waves has already enabled tests of general relativity that were impossible a decade ago.
View original technical description
This proposal contains the funding request to support the activities of the LIGO Gravitational Wave (GW) group at the University of Birmingham. Over the years the group has made significant contributions to the LIGO programme and many of its successes through activities in all the main areas of GW research, spanning (i) detector construction for the STFC-funded Advanced LIGO and LIGO A+ project, (ii) detector commissioning and R&D for novel technological solutions for future upgrades of the detectors hosted in existing facilities, (iii) theoretical research aiming at the development of precise, accurate and computationally efficient gravitational waveforms from the full range of compact binaries - binary neutron stars, neutron star-black holes, and binary black holes - and (iv) science analyses of detected compact binaries to characterise their properties and gain new insights in astrophysics and fundamental physics. The proposed programme is the natural evolution of the group's current activities and is driven by the roles and responsibilities that its members have within the LIGO-Virgo-KAGRA Collaboration (LVK). The programme focuses on some of the highest priority items identified in the LVK white papers for Operations, Observational and Instrument Science, and Communication and Education. This programme further ensures the continuation of leadership for UK frontier research as set out in STFC strategic delivery plan and the PAAP roadmap. The programme is articulated into five scientific themes: Theme 1: Inertial and position sensors for LIGO. Achieving the design sensitivity of the LIGO A# upgrades at 5-25 Hz requires improvements in vibrational isolation technologies. In this theme, we rely on our earlier developments of interferometric position sensors with sub-pm precision and optical seismometers to make the technologies compatible with the LIGO infrastructure, validate them at the MIT LIGO facility, and reach TRL 7. Theme 2: Direct coating thermal noise measurements. Coating thermal noise sets the LIGO peak sensitivity at about 100 Hz. At our newly developed coating testing facility, we will fully characterise TiO2:GeO2/SiO2 coatings and crystalline GaAs/AlGaAs coatings that are prime candidates to meet the requirements of the post-O5 upgrades with the goal of achieving TRL 6. Theme 3: Untangling signatures of eccentricity and spins in binary black hole mergers. General-relativistic spin-induced precession and orbital eccentricity in binary black holes are key tracers for determining their astrophysical origin and indispensable ingredients of robust strong-gravity tests, as they leave unique, measurable imprints in the emitted GW signal. For the first time, we will model and extract their strong-field signatures using the hundreds of events detected by O5. Theme 4: Characterising the population of neutron star-black hole binaries. By the end of O4 the neutron star-black hole binary population will count approximately 10 systems, a number that will further grow during O5. Combining the development of new, highly accurate waveform models, which include spin-induced precession, tidal effects and higher order modes, with classification agnostic population inference, we will infer the most accurate (to-date) merger rate and mass/spin distribution of these sources, and constrain the equation of state of supranuclear density matter. Theme 5: Support for Advanced LIGO operations. We will continue the support and commissioning of the Birmingham-provided hardware for the A+ O5 upgrade and the detectors' operation. The group’s research activities feed into a wide-ranging and vibrant programme of outreach and public engagement initiatives, which will continue during the grant period.
Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.
Is something wrong? Let us know