T. P. Bodiya

Predictions for the Rates of Compact Binary Coalescences Observable by Ground-based Gravitational-wave Detectors

We present an up-to-date, comprehensive summary of the rates for all types of compact binary coalescence sources detectable by the initial and advanced versions of the ground-based gravitational-wave detectors LIGO and Virgo. Astrophysical estimates for compact-binary coalescence rates depend on a number of assumptions and unknown model parameters and are still uncertain. The most confident among these estimates are the rate predictions for coalescing binary neutron stars which are based on extrapolations from observed binary pulsars in our galaxy. These yield a likely coalescence rate of 100 Myr−1 per Milky Way Equivalent Galaxy (MWEG), although the rate could plausibly range from 1 Myr−1 MWEG−1 to 1000 Myr−1 MWEG−1 (Kalogera et al 2004 Astrophys. J. 601 L179; Kalogera et al 2004 Astrophys. J. 614 L137 (erratum)). We convert coalescence rates into detection rates based on data from the LIGO S5 and Virgo VSR2 science runs and projected sensitivities for our advanced detectors. Using the detector sensitivities derived from these data, we find a likely detection rate of 0.02 per year for Initial LIGO–Virgo interferometers, with a plausible range between 2 × 10−4 and 0.2 per year. The likely binary neutron–star detection rate for the Advanced LIGO–Virgo network increases to 40 events per year, with a range between 0.4 and 400 per year.

Optical Dilution and Feedback Cooling of a Gram-Scale Oscillator to 6.9 mK

We report on the use of a radiation pressure induced restoring force, the optical spring effect, to optically dilute the mechanical damping of a 1 g suspended mirror, which is then cooled by active feedback (cold damping). Optical dilution relaxes the limit on cooling imposed by mechanical losses, allowing the oscillator mode to reach a minimum temperature of 6.9 mK, a factor of approximately 40 000 below the environmental temperature. A further advantage of the optical spring effect is that it can increase the number of oscillations before decoherence by several orders of magnitude. In the present experiment we infer an increase in the dynamical lifetime of the state by a factor of approximately 200.

Search for gravitational-wave bursts associated with gamma-ray bursts using data from LIGO science run 5 and VIRGO science run 1.

We present the results of a search for gravitational-wave bursts associated with 137 gamma-ray bursts (GRBs) that were detected by satellite-based gamma-ray experiments during the fifth LIGO science run and first Virgo science run. The data used in this analysis were collected from 2005 November 4 to 2007 October 1, and most of the GRB triggers were from the Swift satellite. The search uses a coherent network analysis method that takes into account the different locations and orientations of the interferometers at the three LIGO-Virgo sites. We find no evidence for gravitational-wave burst signals associated with this sample of GRBs. Using simulated short-duration (<1 s) waveforms, we set upper limits on the amplitude of gravitational waves associated with each GRB. We also place lower bounds on the distance to each GRB under the assumption of a fixed energy emission in gravitational waves, with typical limits of D ~ 15 Mpc (E_GW^iso / 0.01 M_o c^2)^1/2 for emission at frequencies around 150 Hz, where the LIGO-Virgo detector network has best sensitivity. We present astrophysical interpretations and implications of these results, and prospects for corresponding searches during future LIGO-Virgo runs.

Optical coatings and thermal noise in precision measurement

1. Theory of thermal noise in optical mirrors Y. Levin 2. Coating technology S. Chao 3. Compendium of thermal noises in optical mirrors V. B. Braginsky, M. L. Gorodetsky and S. P. Vyatchanin 4. Coating thermal noise I. Martin and S. Reid 5. Direct measurements of coating thermal noise K. Numata 6. Methods of improving thermal noise S. Ballmer and K. Somiya 7. Substrate thermal noise S. Rowan and I. Martin 8. Cryogenics K. Numata and K. Yamamoto 9. Thermo-optic noise M. Evans and G. Ogin 10. Absorption and thermal issues P. Willems, D. Ottaway and P. Beyersdorf 11. Optical scatter J. R. Smith and M. E. Zucker 12. Reflectivity and thickness optimisation I. M. Pinto, M. Principe and R. DeSalvo 13. Beam shaping A. Freise 14. Gravitational wave detection D. Ottaway and S. D. Penn 15. High-precision laser stabilisation via optical cavities M. J. Martin and J. Ye 16. Quantum optomechanics G. D. Cole and M. Aspelmeyer 17. Cavity quantum electrodynamics T. E. Northup.

All-sky search for long-duration gravitational wave transients with LIGO

We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10 - 500 seconds in a frequency band of 40 - 1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. We also report upper limits on the source rate density per year per Mpc^3 for specific signal models. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves.

Structural thermal noise in gram-scale mirror oscillators

The thermal noise associated with mechanical dissipation is a ubiquitous limitation to the sensitivity of precision experiments ranging from frequency stabilization to gravitational wave interferometry. We report on the thermal noise limits to the performance of 1gm mirror oscillators that are part of a cavity optomechanics experiment to observe quantum radiation pressure noise. Thermal noise limits the observed cavity displacement spectrum from 80Hz to 5kHz. We present a calculation of the thermal noise, based on finite element analysis of the dissipation due to structural damping, and find it to be in excellent agreement with the experimental result. We conclude with the predicted thermal noise for an improved oscillator design, which should be capable of revealing the noise that arises from quantum backaction in this system.

Optical Coatings and Thermal Noise in Precision Measurement: List of contributors

1. Theory of thermal noise in optical mirrors Y. Levin 2. Coating technology S. Chao 3. Compendium of thermal noises in optical mirrors V. B. Braginsky, M. L. Gorodetsky and S. P. Vyatchanin 4. Coating thermal noise I. Martin and S. Reid 5. Direct measurements of coating thermal noise K. Numata 6. Methods of improving thermal noise S. Ballmer and K. Somiya 7. Substrate thermal noise S. Rowan and I. Martin 8. Cryogenics K. Numata and K. Yamamoto 9. Thermo-optic noise M. Evans and G. Ogin 10. Absorption and thermal issues P. Willems, D. Ottaway and P. Beyersdorf 11. Optical scatter J. R. Smith and M. E. Zucker 12. Reflectivity and thickness optimisation I. M. Pinto, M. Principe and R. DeSalvo 13. Beam shaping A. Freise 14. Gravitational wave detection D. Ottaway and S. D. Penn 15. High-precision laser stabilisation via optical cavities M. J. Martin and J. Ye 16. Quantum optomechanics G. D. Cole and M. Aspelmeyer 17. Cavity quantum electrodynamics T. E. Northup.

Optical Coatings and Thermal Noise in Precision Measurement: Frontmatter

1. Theory of thermal noise in optical mirrors Y. Levin 2. Coating technology S. Chao 3. Compendium of thermal noises in optical mirrors V. B. Braginsky, M. L. Gorodetsky and S. P. Vyatchanin 4. Coating thermal noise I. Martin and S. Reid 5. Direct measurements of coating thermal noise K. Numata 6. Methods of improving thermal noise S. Ballmer and K. Somiya 7. Substrate thermal noise S. Rowan and I. Martin 8. Cryogenics K. Numata and K. Yamamoto 9. Thermo-optic noise M. Evans and G. Ogin 10. Absorption and thermal issues P. Willems, D. Ottaway and P. Beyersdorf 11. Optical scatter J. R. Smith and M. E. Zucker 12. Reflectivity and thickness optimisation I. M. Pinto, M. Principe and R. DeSalvo 13. Beam shaping A. Freise 14. Gravitational wave detection D. Ottaway and S. D. Penn 15. High-precision laser stabilisation via optical cavities M. J. Martin and J. Ye 16. Quantum optomechanics G. D. Cole and M. Aspelmeyer 17. Cavity quantum electrodynamics T. E. Northup.

Toward the Quantum Ground State of a Gram-Scale Object

We describe an experiment in which coupling between intense optical fields and mirror oscillators is used for generating squeezed states of light, and also for optically cooling a gram-scale mirror oscillator.