Bulletin of the American Physical Society
APS April Meeting 2013
Volume 58, Number 4
Saturday–Tuesday, April 13–16, 2013; Denver, Colorado
Session L10: Gravitational Experiments and Instruments |
Hide Abstracts |
Sponsoring Units: GGR Chair: James Ira Thorpe, NASA Room: Governor's Square 12 |
Sunday, April 14, 2013 3:30PM - 3:42PM |
L10.00001: A new test of short-distance gravity Ted Cook, Eric Adelberger, Erik Swanson We have used a Fourier-Bessel torsion balance to test the Newtonian inverse-square law (ISL) at distances below 50 $\mu$m. Our new limits on ISL-violating Yukawa parameters $\alpha$ and $\lambda$ constrain the maximum size of extra spatial dimensions predicted by string theory and place interesting limits on other exotic interactions such as Chameleon fields. An overview of our experimental methods, current results, and future plans will be presented. [Preview Abstract] |
Sunday, April 14, 2013 3:42PM - 3:54PM |
L10.00002: Update: Parallel-Plate Null Test of the Gravitational Inverse Square Law Charles Hagedorn, Stephan Schlamminger, Matthew Turner, Krishna Venkateswara, Jens Gundlach Gravity has not been experimentally observed at scales smaller than the diameter of human hair, barely smaller than the dark energy length-scale of 85 microns. Our sensitive ($10^{-14}$ N-m/$\sqrt{\mbox{Hz}}$) torsion balance uses a parallel-plate mass configuration to maximize signal and to create a Gauss's Law null-test of short range gravity. Our first science run is complete, and final analysis is underway. The measurement's sensitivity is expected to be comparable to the existing best limits at $\sim56$ microns, but with different leading sources of systematic uncertainty. Sensitivity upgrades are now straightforward, and will commence when our initial results are final. The talk will discuss important systematic effects and analysis challenges inherent to parallel-plate measurements of short-distance forces. [Preview Abstract] |
Sunday, April 14, 2013 3:54PM - 4:06PM |
L10.00003: Regression of Environmental Noise in LIGO data Vaibhav Tiwari, Sergei Klimenko We address the problem of noise regression in the output of gravitational-wave interferometers using data from the environmental monitors (PEM). The objective of the regression analysis is to predict environmental noise in the gravitational-wave (GW) channel from the PEM measurements. One of the most promising regression method is based on the construction of Wiener-Kolmogorov filters. In the presented approach the Wiener-Kolmogorov method has been extended incorporating banks of Wiener filters in the wavelet domain, multi-channel analysis and regulation schemes, which greatly enhance the versatility of the regression analysis. Also we presents the results on regression of the bi-coherent noise in the LIGO data. [Preview Abstract] |
Sunday, April 14, 2013 4:06PM - 4:18PM |
L10.00004: An IndIGO update on LIGO-India Balasubramanian Iyer Plans to extend the two decade long Indian involvement in Gravitational Wave (GW) source modelling and data analysis to GW experiments led to the formation of the Indian Initiative in Gravitational-wave Observations (IndIGO) Consortium in 2009. The IndIGO participation in the setting up of a global network of GW detectors eventually led to the LIGO-India proposal. This talk summarizes the current status of the proposal and the possible future directions of this ambitious Indo-US collaboration. [Preview Abstract] |
Sunday, April 14, 2013 4:18PM - 4:30PM |
L10.00005: Analysis of a dense seismic array to determine sources of Newtonian gravitational noise at the LIGO sites Jennifer Driggers, Jan Harms, Vivien Raymond, Rana Adhikari Newtonian gravitational noise will be an important noise contributor for Advanced LIGO and proposed upgrades to Advanced LIGO, between 5Hz and 30Hz. A major step toward subtracting this Newtonian noise and thus improving the astrophysical detection ability of ground-based gravitational wave observatories is determining the dominant sources of seismic noise, which contribute most strongly to the Newtonian noise. An array of 44 sensors was installed at the LIGO Hanford site for 8 months, including the duration of a commissioning test of a 4km Fabry-Perot cavity. We will show results from this array, including application of LIGO data analysis methods to seismic source localization, relative importance of locally generated versus far-field seismic disturbances, and estimates of residual seismic noise and Newtonian noise present in the cavity length data. We will discuss how this information will help improve noise subtraction algorithms, particularly in terms of optimal sensor placement. [Preview Abstract] |
Sunday, April 14, 2013 4:30PM - 4:42PM |
L10.00006: Laser Frequency Noise Immune Gravitational Wave Detection Jason Hogan, Sheng-wey Chiow, Susannah Dickerson, Peter Graham, Tim Kovachy, Surjeet Rajendran, Alex Sugarbaker, Mark Kasevich Laser frequency noise is a dominant noise background for the detection of gravitational waves using long-baseline optical interferometry. Amelioration of this noise requires near simultaneous strain measurements on more than one interferometer baseline, necessitating, for example, more than two satellites for a space-based detector, or two interferometer arms for a ground-based detector. We describe a new detection strategy based on recent advances in optical atomic clocks and atom interferometry which can operate at long-baselines and which is immune to laser frequency noise [1]. Laser frequency noise is suppressed because the signal arises strictly from the light propagation time between two ensembles of atoms. This new class of sensor allows sensitive gravitational wave detection with only a single baseline. This approach also has practical applications in, for example, the development of ultra-sensitive gravimeters and gravity gradiometers. We show that a space-based detector based on such principles can operate at LISA sensitivity levels and below with just a single measurement arm. We will present recent data from our 10 m ground-based prototype instrument which supports the preliminary instrument design concept. \\[4pt] [1] P. Graham, et. al., arXiv:1206.0818. [Preview Abstract] |
Sunday, April 14, 2013 4:42PM - 4:54PM |
L10.00007: Proposed Single Baseline Atom Interferometry Gravitational Wave Measurements Peter L. Bender A recent paper [P. W. Graham et al., arXiv:1206.0818v1 [gr-qc] 5 Jun 2012] proposed GW measurements using an atom interferometer at each end of a single baseline. The suggested approach makes use of extremely narrow linewidth single photon transitions, such as the 698 nm clock transition in Sr-87. A case discussed has a L $=$ 500 km baseline length between spacecraft, N $=$ 300 large momentum transfer beamsplitters, and a total measurement time of 100 s. The authors point out that many sources of errors in measuring GW signals cancel because they are nearly the same for both parts of the split atom wave functions and/or for both interferometers. Thus a much reduced sensitivity to laser frequency noise is reported. However, it seems that the requirements on this kind of mission are still very demanding. For example, large differences in phase between the 2 parts of the wavefunction for each interferometer appear to be expected due to jitter in the timing of the laser pulses. This makes it more difficult to determine the signs of the desired GW signals. And, because of the 2400 successful state transitions required for an atom to contribute to the signal, even the atom cloud temperature of 100 pK assumed in previous proposals would cause a large loss in signal. In addition, consideration of atom cloud mean velocity differences as low as 1 micron/s and of laser frequency noise of around 1 Hz appears to be needed. [Preview Abstract] |
Sunday, April 14, 2013 4:54PM - 5:06PM |
L10.00008: Detecting high-frequency gravitational waves with optically levitated sensors Andrew Geraci, Asimina Arvanitaki We describe a tunable resonant method for gravitational wave detection using laser-cooled optically levitated sensors in an optical cavity. The approach we describe can exceed the sensitivity of next-generation gravitational wave observatories by up to an order of magnitude in the frequency range of 50-300 kHz, using an instrument of significantly reduced size. Possible sources for GWs at such high frequencies will also be discussed. [Preview Abstract] |
Sunday, April 14, 2013 5:06PM - 5:18PM |
L10.00009: Neutron Interference in the Gravitational Field of a Ring Laser Robert Fischetti A number of analyses of neutron interference effects due to various metric perturbations have been found in the literature [1,2]. However, the approach of each author depends on a specific metric. I will present a new general technique giving the Foldy-Wouthuysen transformed Hamiltonian for a Dirac particle in the most general linearized space-time metric. I will then apply this new technique to calculate the phase shift on a neutron beam interferometer due to the gravitational field of a ring laser [3].\\[4pt] [1] D. M Greenberger and A. W. Overhauser, Rev. Mod. Phys. 51, 43--78 (1979).\\[0pt] [2] F. W. Hehl and W. T. Ni, Phys. Rev. D, vol 42, no. 6, pp. 2045-2048, 1990.\\[0pt] [3] R. L. Mallett, Phys. Lett. A 269, 214 (2000). [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700