Showing 1–7 of 7 results for author: Cumming, A V

LIGO A$^\sharp$: Detector Design and Science Prospects Beyond A+

Authors: L. Sun, K. Kuns, B. J. J. Slagmolen, P. Fritschel, P. Schmidt, B. T. Lantz, S. S. Y. Chua, Divyajyoti, S. W. Ballmer, M. A. Barton, A. V. Cumming, K. L. Dooley, J. C. Driggers, A. Effler, M. Evans, B. Farr, G. González, N. Lu, D. J. Ottaway, C. Palomba, O. J. Piccinni, G. Pratten, S. Raja, A. P. Subhash, P. J. Sutton , et al. (1131 additional authors not shown)

Abstract: We present the LIGO A$^\sharp$ detector concept, an upgrade for the LIGO observatories based on room-temperature interferometers beyond the fifth observing run (O5). Building on the A+ sensitivity, A$^\sharp$ targets broadband sensitivity improvements through heavier test masses, improved suspensions and seismic isolation, increased arm-cavity power, enhanced frequency-dependent squeezing, reduced… ▽ More We present the LIGO A$^\sharp$ detector concept, an upgrade for the LIGO observatories based on room-temperature interferometers beyond the fifth observing run (O5). Building on the A+ sensitivity, A$^\sharp$ targets broadband sensitivity improvements through heavier test masses, improved suspensions and seismic isolation, increased arm-cavity power, enhanced frequency-dependent squeezing, reduced coating thermal noise considering two scenarios, and improved control of mechanical motion and optical modes. We describe the principal design choices, projected noise performance, and corresponding astrophysical prospects. LIGO A$^\sharp$ substantially increases compact-binary detection rates, strengthens population inference, and improves both early-warning times and localization for binary neutron star mergers. The improved sensitivity enables more detailed studies of compact-binary coalescences, including higher-order multipoles, intermediate-mass black holes, remnant black hole ringdown, and the neutron star equation of state. It also broadens the discovery potential for new gravitational-wave sources such as continuous waves and bursts, should enable detection of the stochastic background from compact binary mergers if it remains undetected after O5, and strengthens the role of gravitational-wave detectors as probes of fundamental physics. We discuss key technical challenges and the role of A$^\sharp$ as both a major scientific upgrade for the 2030s and a technology pathfinder for next-generation gravitational-wave observatories, such as Cosmic Explorer. △ Less

Submitted 12 August, 2026; originally announced August 2026.

Comments: 78 pages, 22 figures

Report number: LIGO-P2600307

Extending Ground-Based Gravitational-Wave Sensitivity to 5 Hz

Authors: Amit Singh Ubhi, Lari Koponen, Jiri Smetana, Yulin Xia, Haixing Miao, Emilia Chick, John Bryant, Geraint Pratten, Teng Zhang, Richard Mittleman, Peter Fritschel, Alan V. Cumming, Giles Hammond, Denis Martynov

Abstract: Extending the sensitivity of terrestrial gravitational-wave detectors below 20 Hz is a long-standing challenge, limited by ground motion and inertial sensing noise. In this letter, we demonstrate ultra-high-vacuum compatible inertial isolation and position sensing technologies that achieve active platform stabilization down to 10 mHz. Our laser position sensors reach a sub-pm/$\sqrt{\rm Hz}$ sensi… ▽ More Extending the sensitivity of terrestrial gravitational-wave detectors below 20 Hz is a long-standing challenge, limited by ground motion and inertial sensing noise. In this letter, we demonstrate ultra-high-vacuum compatible inertial isolation and position sensing technologies that achieve active platform stabilization down to 10 mHz. Our laser position sensors reach a sub-pm/$\sqrt{\rm Hz}$ sensitivity above 10 mHz, independent of the input light polarization, representing a 100-fold improvement over the current LIGO position sensors. In addition, our inertial sensors provide at least a factor of 5 improvement in low-frequency sensitivity compared to state-of-the-art commercial seismometers. We integrate these technologies into a LIGO-like interferometer model and predict a low-frequency sensitivity improvement of up to an order of magnitude at 10 Hz, with enhanced linearity and calibration stability. This extension increases the detection horizon for intermediate-mass black hole binaries of mass $10^3 M_\odot$ by a factor of 3. Our results provide the first experimental demonstration of a practical pathway to sub-10 Hz operation of terrestrial gravitational-wave detectors and establish key technologies for next-generation observatories such as Cosmic Explorer and Einstein Telescope. △ Less

Submitted 2 March, 2026; v1 submitted 26 February, 2026; originally announced February 2026.

Sensitivity and control of a 6-axis fused-silica seismometer

Authors: Jiri Smetana, Amit Singh Ubhi, Emilia Chick, Leonid Prokhorov, John Bryant, Artemiy Dmitriev, Alex Gill, Lari Koponen, Haixing Miao, Alan V. Cumming, Giles Hammond, Valery Frolov, Richard Mittleman, Peter Fritchel, Denis Martynov

Abstract: We present a pair of seismometers capable of measurement in all six axes of rigid motion. The vacuum-compatible devices implement compact interferometric displacement sensors to surpass the sensitivity of typical electrical readout schemes. Together with the capability to subtract the sensitivity-limiting coupling of ground tilt into horizontal motion, our seismometers can widen the sensing band t… ▽ More We present a pair of seismometers capable of measurement in all six axes of rigid motion. The vacuum-compatible devices implement compact interferometric displacement sensors to surpass the sensitivity of typical electrical readout schemes. Together with the capability to subtract the sensitivity-limiting coupling of ground tilt into horizontal motion, our seismometers can widen the sensing band towards mHz frequencies. This has notable applications across a range of fields requiring access to low-frequency signals, such as seismology and climate research. We particularly highlight their potential application in gravitational-wave observatories (LIGO) in improving their observation capability of intermediate-mass black holes ($\sim 1000\,M_\odot$). The sensors are based on a near-monolithic fused-silica design consisting of a fused-silica mass and fibre, showing improved stability and robustness to tilt drifts, alignment, and control compared to all-metal or mixed metal-silica designs. We demonstrate tilt sensitivity that surpasses the best commercial alternatives in a significantly reduced footprint compared to our previous iterations of these sensors. △ Less

Submitted 6 January, 2025; v1 submitted 22 May, 2024; originally announced May 2024.

Comments: 12 pages, 3 figures

Design and sensitivity of a 6-axis seismometer for gravitational wave observatories

Authors: Leonid Prokhorov, Sam Cooper, Amit Singh Ubhi, Conor Mow-Lowry, John Bryant, Artemiy Dmitriev, Chiara Di Fronzo, Christopher J. Collins, Alex Gill, Alexandra Mitchell, Joscha Heinze, Jiri Smetana, Tianliang Yan, Alan V. Cumming, Giles Hammond, Denis Martynov

Abstract: We present the design, control system, and noise analysis of a 6-axis seismometer comprising a mass suspended by a single fused silica fibre. We utilise custom-made, compact Michelson interferometers for the readout of the mass motion relative to the table and successfully overcome the sensitivity of existing commercial seismometers by over an order of magnitude in the angular degrees of freedom.… ▽ More We present the design, control system, and noise analysis of a 6-axis seismometer comprising a mass suspended by a single fused silica fibre. We utilise custom-made, compact Michelson interferometers for the readout of the mass motion relative to the table and successfully overcome the sensitivity of existing commercial seismometers by over an order of magnitude in the angular degrees of freedom. We develop the sensor for gravitational-wave observatories, such as LIGO, Virgo, and KAGRA, to help them observe intermediate-mass black holes, increase their duty cycle, and improve localisation of sources. Our control system and its achieved sensitivity makes the sensor suitable for other fundamental physics experiments, such as tests of semiclassical gravity, searches for bosonic dark matter, and studies of the Casimir force. △ Less

Submitted 24 July, 2023; originally announced July 2023.

Proposed large scale monolithic fused silica mirror suspension for 3rd generation gravitational wave detectors

Authors: A. V. Cumming, R. Jones, G. D. Hammond, J. Hough, I. W. Martin, S. Rowan

Abstract: Thermal noise from the suspension fibres used in the mirror pendulums in current gravitational wave detectors is a critical noise source. Future detectors will require improved suspension performance with the specific ability to suspend much heavier masses to reduce radiation pressure noise, whilst retaining good thermal noise performance. In this letter, we propose and experimentally demonstrate… ▽ More Thermal noise from the suspension fibres used in the mirror pendulums in current gravitational wave detectors is a critical noise source. Future detectors will require improved suspension performance with the specific ability to suspend much heavier masses to reduce radiation pressure noise, whilst retaining good thermal noise performance. In this letter, we propose and experimentally demonstrate a design for a large-scale fused silica suspension, demonstrating its suitability for holding an increased mass of 160 kg. We demonstrate the concepts for improving thermal noise via longer suspension fibres supporting a higher static stress. We present a full thermal noise analysis of our prototype, meeting requirements for conceptual 3rd generation detector designs such as the high frequency interferometer of the Einstein Telescope (ET-HF), and closely approaching that required for Cosmic Explorer (CE). △ Less

Submitted 17 November, 2021; originally announced November 2021.

Comments: 7 pages, 5 figures

Design of a speed meter interferometer proof-of-principle experiment

Authors: C. Gräf, B. W. Barr, A. S. Bell, F. Campbell, A. V. Cumming, S. L. Danilishin, N. A. Gordon, G. D. Hammond, J. Hennig, E. A. Houston, S. H. Huttner, R. A. Jones, S. S. Leavey, H. Lück, J. Macarthur, M. Marwick, S. Rigby, R. Schilling, B. Sorazu, A. Spencer, S. Steinlechner, K. A. Strain, S. Hild

Abstract: The second generation of large scale interferometric gravitational wave detectors will be limited by quantum noise over a wide frequency range in their detection band. Further sensitivity improvements for future upgrades or new detectors beyond the second generation motivate the development of measurement schemes to mitigate the impact of quantum noise in these instruments. Two strands of develo… ▽ More The second generation of large scale interferometric gravitational wave detectors will be limited by quantum noise over a wide frequency range in their detection band. Further sensitivity improvements for future upgrades or new detectors beyond the second generation motivate the development of measurement schemes to mitigate the impact of quantum noise in these instruments. Two strands of development are being pursued to reach this goal, focusing both on modifications of the well-established Michelson detector configuration and development of different detector topologies. In this paper, we present the design of the world's first Sagnac speed meter interferometer which is currently being constructed at the University of Glasgow. With this proof-of-principle experiment we aim to demonstrate the theoretically predicted lower quantum noise in a Sagnac interferometer compared to an equivalent Michelson interferometer, to qualify Sagnac speed meters for further research towards an implementation in a future generation large scale gravitational wave detector, such as the planned Einstein Telescope observatory. △ Less

Submitted 11 September, 2014; v1 submitted 12 May, 2014; originally announced May 2014.

Comments: Revised version: 16 pages, 6 figures

Journal ref: Class. Quantum Grav. 31 215009 (2014)

The 10m AEI prototype facility A brief overview

Authors: Tobias Westphal, Gerald Bergmann, Alessandro Bertolini, Michael Born, Yanbei Chen, Alan V Cumming, Liam Cunningham, Katrin Dahl, Christian Graef, Giles Hammond, Gerhard Heinzel, Stefan Hild, Sabina Huttner, Russel Jones, Fumiko Kawazoe, Sina Koehlenbeck, Gerrit Kuehn, Harald Lueck, Kasem Mossavi, Jan H Poeld, Kentaro Somiya, Marielle van Veggel, Alexander Wanner, Benno Willke, Ken A Strain , et al. (2 additional authors not shown)

Abstract: The AEI 10 m prototype interferometer facility is currently being constructed at the Albert Einstein Institute in Hannover, Germany. It aims to perform experiments for future gravitational wave detectors using advanced techniques. Seismically isolated benches are planned to be interferometrically interconnected and stabilized, forming a low-noise testbed inside a 100 m^3 ultra-high vacuum system.… ▽ More The AEI 10 m prototype interferometer facility is currently being constructed at the Albert Einstein Institute in Hannover, Germany. It aims to perform experiments for future gravitational wave detectors using advanced techniques. Seismically isolated benches are planned to be interferometrically interconnected and stabilized, forming a low-noise testbed inside a 100 m^3 ultra-high vacuum system. A well-stabilized high power laser will perform differential position readout of 100 g test masses in a 10 m suspended arm-cavity enhanced Michelson interferometer at the crossover of measurement (shot) noise and backaction (quantum radiation pressure) noise, the so-called Standard Quantum Limit (SQL). Such a sensitivity enables experiments in the highly topical field of macroscopic quantum mechanics. In this article we introduce the experimental facility and describe the methods employed, technical details of subsystems will be covered in future papers. △ Less

Submitted 28 December, 2011; v1 submitted 30 November, 2011; originally announced November 2011.