A. F. Helmling-Cornell
A5102838407- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Geophysics and Sensor Technology
- High-pressure geophysics and materials
- Seismic Waves and Analysis
- Atomic and Subatomic Physics Research
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Mechanical and Optical Resonators
- Advanced Frequency and Time Standards
- Magnetic confinement fusion research
- Dark Matter and Cosmic Phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Solar and Space Plasma Dynamics
- Meteorological Phenomena and Simulations
- Astronomical Observations and Instrumentation
- Black Holes and Theoretical Physics
- Radioactivity and Radon Measurements
- Statistical and numerical algorithms
- Superconducting Materials and Applications
- Radioactive contamination and transfer
- Seismology and Earthquake Studies
University of Oregon
2019-2024
Purdue University West Lafayette
2018
The Laser Interferometer Gravitational Wave Observatory (LIGO) has been directly detecting gravitational waves from compact binary mergers since 2015. We report on the first use of squeezed vacuum states in direct measurement with Advanced LIGO H1 and L1 detectors. This achievement is culmination decades research to implement gravitational-wave During ongoing O3 observation run, are improving sensitivity interferometers signals above 50 Hz by up 3 dB, thereby increasing expected detection...
On April 1st, 2019, the Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO), joined by Virgo detector, began third observing run, a year-long dedicated search for gravitational radiation. The LIGO detectors have achieved higher duty cycle and greater sensitivity to waves than ever before, with Hanford achieving angle-averaged binary neutron star coalescences distance of 111 Mpc, Livingston 134 Mpc factors 74.6% 77.0% respectively. improvement in stability is result several...
The characterization of the Advanced LIGO detectors in second and third observing runs has increased sensitivity instruments, allowing for a higher number detectable gravitational-wave signals, provided confirmation all observed events. In this work, we present methods used to characterize curate publicly available datasets, including strain data quality products. We describe essential role these datasets LIGO-Virgo Collaboration analyses gravitational-waves from both transient persistent...
Quantum noise imposes a fundamental limitation on the sensitivity of interferometric gravitational-wave detectors like LIGO, manifesting as shot and quantum radiation pressure noise. Here, we present first realization frequency-dependent squeezing in full-scale detectors, resulting reduction both noise, with broadband detector enhancement from tens hertz to several kilohertz. In LIGO Hanford detector, reduced amplitude by factor 1.6 (4.0 dB) near 1 kHz; Livingston was 1.9 (5.8 dB). These...
The motion of a mechanical object, even human-sized should be governed by the rules quantum mechanics. Coaxing them into state is, however, difficult because thermal environment masks any signature object's motion. also effects proposed modifications mechanics at large mass scales. We prepared center-of-mass 10-kilogram oscillator in with an average phonon occupation 10.8. reduction temperature, from room temperature to 77 nanokelvin, is commensurate 11 orders-of-magnitude suppression...
Gravitational Wave interferometers achieve their profound sensitivity by combining a Michelson interferometer with optical cavities, suspended masses, and now, squeezed quantum states of light. These modify the measurement process LIGO, VIRGO GEO600 to reduce noise that masks astrophysical signals; thus, improvements squeezing are essential further expand our gravitational view universe. Further reducing will require both lowering decoherence from losses as well more sophisticated...
Progress in gravitational-wave astronomy depends upon having sensitive detectors with good data quality. Since the end of LIGO-Virgo-KAGRA third Observing run March 2020, detector-characterization efforts have lead to increased sensitivity detectors, swifter validation candidates and improved tools used for data-quality products. In this article, we discuss these detail their impact on our ability detect study gravitational-waves. These include multiple instrumental investigations that led...
Precision measurements of space and time, like those made by the detectors Laser Interferometer Gravitational-wave Observatory (LIGO), are often confronted with fundamental limitations imposed quantum mechanics. The Heisenberg uncertainty principle dictates that position momentum an object cannot both be precisely measured, giving rise to apparent limitation called Standard Quantum Limit (SQL). Reducing noise below SQL in gravitational-wave detectors, where photons used continuously measure...
The Heisenberg uncertainty principle dictates that the position and momentum of an object cannot be simultaneously measured with arbitrary precision, giving rise to apparent limitation known as standard quantum limit (SQL). Gravitational-wave detectors use photons continuously measure positions freely falling mirrors so are affected by SQL. We investigated performance Laser Interferometer Gravitational-Wave Observatory (LIGO) after experimental realization frequency-dependent squeezing...
Noise due to scattered light has been a frequent disturbance in the Advanced LIGO gravitational wave detectors, hindering detection of waves. The non stationary scatter noise caused by low frequency motion can be recognized as arches time-frequency plane channel. In this paper, we characterize scattering for LIGO's third observing run O3 from April, 2019 March, 2020. We find at least two different populations and investigate multiple origins one them well its mitigation. that relative...
Teleseismic, or distant, earthquakes regularly disrupt the operation of ground--based gravitational wave detectors such as Advanced LIGO. Here, we present \emph{EQ mode}, a new global control scheme, consisting an automated sequence optimized filters that reduces and coordinates motion seismic isolation platforms during earthquakes. This, in turn, suppresses differential interferometer arms with respect to one another, resulting reduction DARM signal at frequencies below 100\,mHz. Our method...
Abstract The extreme sensitivity required for direct observation of gravitational waves by the Advanced LIGO detectors means that environmental noise is increasingly likely to contaminate wave signals if left unaddressed. Consequently, monitoring efforts have been undertaken and novel mitigation techniques developed which reduced coupling made it possible analyze artifacts with potential affect 90 events detected from 2015–2020 detectors. So far, there no evidence contamination in...
Small, highly absorbing points are randomly present on the surfaces of main interferometer optics in Advanced LIGO. The resulting nano-meter scale thermo-elastic deformations and substrate lenses from these micron-scale absorbers significantly reduces sensitivity directly though a reduction power-recycling gain indirect interactions with feedback control system. We review expected surface deformation point provide pedagogical description impact power build-up second generation gravitational...
The sensitivity of the Advanced LIGO detectors to gravitational waves can be affected by environmental disturbances external themselves. Since transition from former initial phase, many improvements have been made equipment and techniques used investigate these effects. These methods aided in tracking down mitigating noise sources throughout first three observing runs advanced detector era, keeping ambient contribution below background levels detectors. In this paper we describe how they led...
Radioactivity is understood to be described by a Poisson process, yet some measurements of nuclear decays appear exhibit unexpected variations. Generally, the isotopes reporting these variations have long half lives, which are plagued large measurement uncertainties. In addition inherent problems, there reports time-dependent decay rates and even claims exotic neutrino-induced We present dedicated experiment for stable long-term gamma emissions resulting from β decays, will provide...
On May 24th, 2023, the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO), joined by Virgo and KAGRA detectors, began fourth observing run for a two-year-long dedicated search gravitational waves. The LIGO Hanford Livingston detectors have achieved an unprecedented sensitivity to waves, with angle-averaged median range binary neutron star mergers of 152 Mpc 160 Mpc, duty cycles 65.0% 71.2%, respectively, coincident cycle 52.6%. maximum detector is 165 177 both during second...
Advanced LIGO and Virgo have detected gravitational waves from astronomical sources to open a new window on the Universe. To explore this realm requires an exquisite level of detector sensitivity, meaning that much stronger signal instrumental environmental noise must be rejected. Selected examples unwanted in are presented. The initial focus is how existence (characterized by particular frequencies or time intervals) was discovered. Then, variety methods used track down source noise, e.g.,...
High-quality optical resonant cavities require low loss, typically on the scale of parts per million. However, unintended micron-scale contaminants resonator mirrors that absorb light circulating in cavity can deform surface thermoelastically and thus increase losses by scattering out mode. The point absorber effect is a limiting factor some high-power experiments, for example, Advanced LIGO gravitational-wave detector. In this Letter, we present general approach to from first principles...
The extreme sensitivity required for direct observation of gravitational waves by the Advanced LIGO detectors means that environmental noise is increasingly likely to contaminate wave signals if left unaddressed. Consequently, monitoring efforts have been undertaken and novel mitigation techniques developed which reduced coupling made it possible analyze artifacts with potential affect 90 events detected from 2015-2020 detectors. So far, there no evidence contamination in detections....