D. Ganapathy
A5036488949- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- High-pressure geophysics and materials
- Geophysics and Sensor Technology
- Cosmology and Gravitation Theories
- Atomic and Subatomic Physics Research
- Advanced Frequency and Time Standards
- Mechanical and Optical Resonators
- Magnetic confinement fusion research
- Dark Matter and Cosmic Phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Superconducting Materials and Applications
- Astrophysics and Cosmic Phenomena
- Radiology practices and education
- Quantum Information and Cryptography
- Nonlinear Dynamics and Pattern Formation
- Neural dynamics and brain function
- Solar and Space Plasma Dynamics
- Spectroscopy and Quantum Chemical Studies
- Advanced Fiber Laser Technologies
- earthquake and tectonic studies
- Quantum Mechanics and Applications
- Seismic Waves and Analysis
Massachusetts Institute of Technology
2020-2025
LIGO Scientific Collaboration
2024
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 first detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2015 launched era gravitational-wave astronomy. quest for signals from objects that are fainter or farther away impels technological advances to realize ever more sensitive detectors. Since 2019, one advanced technique, injection squeezed states light, is being used improve shot-noise limit sensitivity Advanced LIGO detectors, at frequencies above ∼50 Hz. Below this frequency,...
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...
Gravitational waves produced at kilohertz frequencies in the aftermath of a neutron star collision can shed light on behavior matter extreme temperatures and densities that are inaccessible to laboratory experiments. Gravitational-wave interferometers limited by quantum noise these but be tuned via their optical configuration maximize probability postmerger signal detection. We compare two such tuning strategies turn Advanced LIGO into postmerger-focused instrument: first, wideband enhances...
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...
Vacuum quantum fluctuations impose a fundamental limit on the sensitivity of gravitational-wave interferometers, which rank among most sensitive precision measurement devices ever built. The injection conventional squeezed vacuum reduces noise in one quadrature at expense increasing other. While this approach improved Advanced LIGO and Virgo interferometers during their third observing run (O3), future improvements arm power squeezing levels will bring radiation pressure to forefront....
Squeezed vacuum states are now employed in gravitational-wave interferometric detectors, enhancing their sensitivity and thus enabling richer astrophysical observations. In future observing runs, the detectors will incorporate a filter cavity to suppress quantum radiation pressure noise using frequency-dependent squeezing. Interferometers employing internal external cavities decohere degrade squeezing complex new ways, which must be studied achieve increasingly ambitious goals. This paper...
Quantum vacuum fluctuations fundamentally limit the precision of optical measurements, such as those in gravitational-wave detectors. Injection conventional squeezed can be used to reduce quantum noise readout quadrature, but this reduction is at cost increasing orthogonal quadrature. For detectors near limits imposed by radiation pressure (QRPN), both quadratures impact measurement, and benefits squeezing are limited. In paper, we demonstrate use a critically-coupled 16m cavity diminish...
The observables of a noisy quantum system can be estimated by appropriately filtering the records their continuous measurement. Such is relevant for state estimation, and if filter causal, also measurement-based feedback control. It therefore imperative that pair conjugate causally satisfy Heisenberg uncertainty principle. In this article, we prove fact---without assuming Markovian dynamics or Gaussian noises, in presence absence control system, where loop (inside outside) measurement record...
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...
The observables of a noisy quantum system can be estimated by appropriately filtering the records their continuous measurement. Such is relevant for state estimation and measurement-based feedback control. It therefore imperative that through causal filter satisfy Heisenberg uncertainty principle. In Markovian setting, prior work implicitly guarantees this requirement. We show any estimate linear linear, but not necessarily Markovian, will particular, true irrespective control where in loop...