Bulletin of the American Physical Society
APS April Meeting 2017
Volume 62, Number 1
Saturday–Tuesday, January 28–31, 2017; Washington, DC
Session J6: Testing General Relativity with Black Hole ObservationsFocus
|
Hide Abstracts |
Sponsoring Units: DGRAV Chair: Leo Stein, Caltech Room: Virginia C |
Sunday, January 29, 2017 10:45AM - 11:21AM |
J6.00001: Tests of general relativity from gravitational wave observations of binary black holes Invited Speaker: Walter Del Pozzo Gravitational waves emitted during the coalescence of compact binary systems carry a wealth of information about the merging objects, the remnant object as well as their interaction with space-time. The description of the dynamics of such systems is based on solutions of the theory of general relativity. For any given physical configuration of masses, spins and orbital motion, general relativity predicts the dynamical evolution of the binary system as well as the corresponding gravitational wave signal. During the coalescence of extremely compact objects such as binary black holes, the typical curvature and velocity at play are such that, from the observation of the gravitational wave signal, we can access the most extreme dynamical regimes of gravity. In such conditions, we can test our understanding of gravity by looking for potential departures between the solutions of general relativity and the actual dynamics of space-time. The LIGO observations GW150914 and GW151226 provided wonderful testing grounds for general relativity in the, up to now unaccessible, strong-field dynamical regime of gravity. During my talk, I will review and discuss several of the tests that have been devised to detect violations of the predictions of general relativity from the observation of gravitational waves from coalescing binary systems. The discussion will be based on the results of the analysis of GW150914 and GW151226. Finally, I will conclude by discussing some of the future prospects of extending the current state-of-the-art methodologies to further aspects of general relativity. [Preview Abstract] |
Sunday, January 29, 2017 11:21AM - 11:33AM |
J6.00002: Testing general relativity with black-hole binary observations: results and prospects Michele Vallisneri The first two LIGO-Virgo detections of gravitational waves from binary black-hole inspirals offered the first opportunity to test gravitation in its strong-field, relativistic-motion, and radiative sector. The initial tests reported in PRL 116 (2016) probed consistency with the predictions of general relativity, to moderate precision. The space-based observatory LISA will observe black-hole binary signals with much larger SNRs, allowing for even more precise tests. Last, the detection of a binary black-hole stochastic background with pulsar-timing arrays will offer more constraints on the speed and polarizations of gravitational waves. I review these results and examine synergies across the gravitational-wave spectrum. I discuss the main challenges and opportunities from the viewpoint of data analysis, and outline prospects for making contact with current alternative theories of gravitation, in particular those motivated by models of dark energy. [Preview Abstract] |
Sunday, January 29, 2017 11:33AM - 11:45AM |
J6.00003: Probing Extreme Gravity with GW150914 and GW151226 Kent Yagi, Nicolas Yunes, Frans Pretorius Advanced LIGO's recent discovery of the direct detection of gravitational waves from binary black hole coalescences allow us to probe gravity, for the first time, in extreme gravity regime where the field is both strong and dynamical. In this talk, I will describe how well GW150914 and GW151226 probe fundamental pillars of General Relativity, such as the equivalence principle, Lorentz invariance and massless graviton. I will then compare such new bounds to the existing bounds from Solar System experiments and binary pulsar observations. I will finally explain current limitations of probing extreme gravity with gravitational wave observations and discuss what needs to be done in future. [Preview Abstract] |
Sunday, January 29, 2017 11:45AM - 11:57AM |
J6.00004: Spectroscopic analysis of stellar mass black-hole mergers in our local universe with ground-based gravitational wave detectors Swetha Bhagwat, Duncan Brown, Stefan Ballmer Motivated by the recent discoveries of binary black-hole mergers by the Advanced Laser Interferometer Gravitational-wave Observatory (Advanced LIGO), we investigate the prospects of ground based detectors to perform a spectroscopic analysis of signals emitted during the ringdown of the Kerr black-hole formed by a stellar mass binary black-hole merger. We investigate the detectability and resolvability of the sub-dominant modes l = m = 3, l = m = 4 and l = 2;m = 1. We find that new ground-based facilities such as Einstein Telescope or Cosmic Explorer could measure multiple ringdown modes in over 300 events per year. We also investigate detector tuning for ringdown oriented searches. [Preview Abstract] |
Sunday, January 29, 2017 11:57AM - 12:09PM |
J6.00005: Modeling Gravitational Waves to Test GR Dispersion and Polarization Rhondale Tso, Yanbei Chen, Maximilliano Isi Given continued observation runs from the Laser Interferometer Gravitational-Wave Observatory Scientific Collaboration, further gravitational wave (GW) events will provide added constraints on beyond-general relativity (b-GR) theories. One approach, independent of the GW generation mechanism at the source, is to look at modification to the GW dispersion and propagation, which can accumulate over vast distances. Generic modification of GW propagation can also, in certain b-GR theories, impact the polarization content of GWs. To this end, a comprehensive approach to testing the dispersion and polarization content is developed by modeling anisotropic deformations to the waveforms’ phase, along with birefringence effects and corollary consequences for b-GR polarizations, i.e., breathing, vector, and longitudinal modes. Such an approach can be mapped to specific theories like Lorentz violation, amplitude birefringence in Chern-Simons, and provide hints at additional theories to be included. An overview of data analysis routines to be implemented will also be discussed. [Preview Abstract] |
Sunday, January 29, 2017 12:09PM - 12:21PM |
J6.00006: Theory-Agnostic Tests of GR with Multi-Band Gravitational Waves Nicolas Yunes, Enrico Barausse, Katherine Chamberlain The aLIGO detection of the black-hole binary GW150914 opened a new era for testing General Relativity in extreme gravity. One generic feature that can be constrained is the emission of dipole gravitational radiation by compact binaries. This is excluded to high accuracy in binary pulsars, but entire classes of gravitational theories predict this effect in binaries predominantly (or only) involving black holes. In this talk, I will describe how future, joint observations of GW150914-like systems by aLIGO and eLISA will dramatically improve bounds on dipole emission from black-hole binaries, probing extreme gravity with unprecedented accuracy. [Preview Abstract] |
Sunday, January 29, 2017 12:21PM - 12:33PM |
J6.00007: Gravitational Wave Tests of General Relativity with Future Detectors Katie Chamberlain, Nicolas Yunes Gravitational Wave detections with aLIGO have given us unrivalled insight into the extreme gravity regime, in which the gravitational field is strong and dynamical, but where will these types of detections be in 20 years? In this talk, we will explore how the construction of future generations of gravitational wave detectors influences our ability to test General Relativity in extreme gravity. In particular, using the noise spectra for aLIGO, A+, Voyager, CE, and ET-B, as well as the eLISA configurations N2A1, N2A2, and N2A5, we will compare the constraints that eLISA will provide to those that future generations of aLIGO will provide. These studies should produce useful information about instrument design to help guide design of future detectors for tests of gravity. [Preview Abstract] |
Sunday, January 29, 2017 12:33PM - 12:45PM |
J6.00008: Comparing Black hole Shadow Widths in the Equatorial Plane for General Relativity and Selected Alternative Theories of Gravity James Graber Results from ongoing efforts to measure the black hole shadows expected from Sgr A* and M87, e.g. by the Event-Horizon Telescope, could soon confirm or refute the Kerr nature of the black-hole shadow, thereby helping confirm or refute General Relativity. It is fairly easy to precisely calculate the width of the shadow of a compact, cylindrically symmetric rotating object in its equatorial plane. We have calculated these shadow widths for three different metrics: 1) the standard Kerr metric, 2) a rotating perturbed Kerr object with a quadrupole moment similar to a neutron star’s, as computed by Frutos-Alfaro based on the earlier Manko et al. neutron-star metric, and 3) also for a new rotating metric based on the Yilmaz exponential metric. For reasonable (plausible) parameter values, the differences in calculated shadow widths are of the order of ten percent, which may be difficult to measure. We graphically present comparisons between the expected Kerr value for the shadow width, and the widths computed for the alternative metrics as a numerically computed function of the rotation and the quadrupole moment. If time allows, we may present similar calculations and graphs for the shadow widths of rotating compact objects from other alternative theories of gravity. [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