Bulletin of the American Physical Society
APS April Meeting 2021
Volume 66, Number 5
Saturday–Tuesday, April 17–20, 2021; Virtual; Time Zone: Central Daylight Time, USA
Session D16: Tests of General Relativity with Gravitational Waves ILive
|
Hide Abstracts |
Sponsoring Units: DGRAV Chair: Kent Yagi, Univ. of Virginia |
Saturday, April 17, 2021 1:30PM - 1:42PM Live |
D16.00001: Probing modified gravitational-wave propagation through tidal measurements of binary neutron star mergers Nan Jiang, Kent Yagi Gravitational-wave(GW) sources can serve as standard sirens to probe cosmology by measuring their luminosity distance and redshift. Such standard sirens are also useful to probe theories beyond General Relativity with a modified GW propagation. Previous studies on the latter assume multi-messenger observations so that the luminosity distance can be measured with GWs while the redshift is obtained by identifying sources’ host galaxies from electromagnetic (EM) counterparts. Given that GW events of binary neutron star(BNS) coalescences with associated EM counterpart detections are expected to be rather rare, it is important to examine the possibility of using standard sirens to probe gravity with GW measurements alone. In this paper, we achieve this by extracting the redshift from the tidal measurement of BNSs(originally proposed within the context of GW cosmology). We also improve previous work by considering multi-band GW observations between ground-based (e.g.Einstein Telescope) and space-based (e.g.DECIGO) interferometers. We find that such multi-band observations with the tidal information can constrain a parametric non-Einsteinian deviation in the luminosity distance more stringently than the case with EM counterparts (due to a larger number of events) by a factor of a few. [Preview Abstract] |
Saturday, April 17, 2021 1:42PM - 1:54PM Live |
D16.00002: Gravitational Wave lensing beyond Einstein’s General Relativity Miguel Zumalacarregui Gravitational lensing of light is a well established test of gravity. However, little is known about how gravitational waves (GW) propagate beyond the simplest space-times in theories beyond Einstein’s General Relativity (GR). I will present a framework for GW lensing beyond GR at leading order in frequency. The modified causal structure and kinetic mixing between metric and additional degrees of freedom leads to new phenomena, providing clear-cut tests that do not require an electromagnetic counterpart. I will present detailed predictions for static, spherically symmetric lenses in an quartic Horndeski theory in which novel GW lensing effects can provide tests far more stringent than the multi-messenger event GW170817. The next terms in the frequency expansion will further enrich the phenomenology of GW lensing and enable new precision tests of gravity. [Preview Abstract] |
Saturday, April 17, 2021 1:54PM - 2:06PM Live |
D16.00003: Angular emission patterns of remnant black-holes Xiang Li, Ling Sun, Rico Ka Lok Lo, Ethan Payne, Yanbei Chen The final stage of a binary black-hole merger, the ringdown, is described by the Teukolsky Equation, which predicts both the temporal and angular dependencies. Many studies have focused on black-hole spectroscopy, while the angular distribution has not been extensively investigated. In this work, by introducing a novel global fitting procedure over both time and angular dependencies, we further study the spatial distribution of ringdown waveforms. We show that spin-weighted spheroidal harmonics are a better representation of angular emission pattern when compared to spin-weighted spherical ones, and that their differences are distinguishable in numerical relativity waveforms. In the presentation, we will qualitatively draw the relation between the progenitor binary properties and the excitation of quasinormal modes, including higher-order angular modes and overtones. Specifically, we show that the retrograde modes will be excited when the primary black hole's spin in a large mass ratio binary is not aligned with the orbital angular momentum. Our work seeks to inspire a strategy of testing the ringdown angular emission pattern by stacking multiple gravitational-wave events, as a single event cannot be observed from multiple directions to allow for a global fitting. [Preview Abstract] |
Saturday, April 17, 2021 2:06PM - 2:18PM Live |
D16.00004: Dynamical scalarization and descalarization in binary black hole mergers Helvi Witek, Hector O. Silva, Matthew Elley, Nicolas Yunes Scalar fields coupled to the Gauss-Bonnet invariant can undergo a tachyonic instability, leading to spontaneous scalarization of black holes. Studies of this effect have so far been restricted to single black hole spacetimes. We present the first results on dynamical scalarization in head-on collisions and quasi-circular inspirals of black hole binaries with numerical relativity simulations. We show that black hole binaries can either form a scalarized remnant or dynamically descalarize by shedding off its initial scalar hair. The observational implications of these finding are discussed. [Preview Abstract] |
Saturday, April 17, 2021 2:18PM - 2:30PM Live |
D16.00005: Constraints on the quasi-normal mode frequencies of the LIGO-Virgo signals by making use of a full gravitational-wave model Abhirup Ghosh, Richard Brito, Alessandra Buonanno The no-hair conjecture in General Relativity states that the properties of an astrophysical Kerr black hole (BH) are completely described by its mass and spin angular momentum. As a consequence, the complex quasi-normal-mode (QNM) frequencies of a binary black hole (BBH) ringdown can be uniquely determined by the mass and spin of the remnant object. Conversely, independent measurements of QNM frequencies could be a test of the conjecture. Here, we outline a test of the no-hair conjecture by measuring the complex QNM ringdown frequencies using, for the first time, a spinning inspiral-merger-ringdown waveform model. We thus take advantage of the entire signal power and remove dependency on the predicted or estimated start time of the proposed ringdown. We demonstrate the robustness of our test against modified gravitational wave (GW) signals with a ringdown different from a GR prediction, as well as possible noise systematics. Finally, we use our method to analyse properties of the merger remnants for all relevant BBH events observed by LIGO-Virgo to date including, for the first time, events from the first two observing runs. We report the strongest constraints yet, using our method, on the measurements of the frequency and damping time of least-damped QNM. [Preview Abstract] |
Saturday, April 17, 2021 2:30PM - 2:42PM Live |
D16.00006: Black Hole Spectroscopy Horizons and the Impact of Overtones Cecilia Chirenti, Iara Ota Black hole spectroscopy is the proposal to observe multiple quasinormal modes in the ringdown of a binary black hole merger. In addition to the fundamental quadrupolar mode, overtones and higher harmonics may be present and detectable in the gravitational wave signal, allowing for tests of the no-hair theorem. We obtain the spectroscopy horizons of current and future detectors, up to which one or more additional modes can be detected (and confidently distinguished from each other). For the detection of one additional mode, the spectroscopy horizon of the first overtone is consistently larger than that of any higher harmonic modes for all detectors in the entire mass range, except close to the highest mass (lowest frequency) limit for detectability. We use both a Fisher matrix approach and a Bayesian model comparison to confirm our results. [Preview Abstract] |
Saturday, April 17, 2021 2:42PM - 2:54PM Live |
D16.00007: Searching for exotic compact objects with expanded gravitational wave templates Richard George, Horng Sheng Chia, Thomas Edwards, Christian Setzer, Cody Messick, Aaron Zimmerman If they exist, exotic compact objects may have large spin-induced quadrupole moments which are not accounted for in current template-based gravitational wave searches. The phase evolution due to these quadrupole moments can cause these systems to be missed by these searches, especially at lower masses. We propose to search for such exotic stars by including the effect of large-spin induced quadrupoles, through the introduction of dimensionless quadrupole parameters in our templates. The current hurdle is reducing the computational cost of a search which uses a six parameter template bank. I will discuss our effort to construct waveform models with fewer parameters, which match the 6 parameter model at 99{\%} effectualness, and our preliminary search results. [Preview Abstract] |
Saturday, April 17, 2021 2:54PM - 3:06PM Live |
D16.00008: Effects of dynamical dark-matter distributions on intermediate mass-ratio inspirals (IMRIs) David Nichols, Bradley Kavanagh, Gianfranco Bertone, Daniele Gaggero Dense distributions of cold dark matter can form around massive black holes, and the dark matter can change the rate of inspiral of a small compact object into the massive black hole. The dark matter induces an additional drag on the compact object through dynamical friction, and this accelerates the inspiral of the small compact object. Previous studies of these systems assumed the dark matter distribution was static as the compact object inspirals, and they found dynamical friction can have a significant effect. We show for many IMRI systems that energy balance requires that dark matter redistributes in response to the inspiral of the compact object. We develop a formalism for jointly evolving the dynamics of the dark matter and the inspiraling compact object. We find that dynamical friction can still play a substantial role in the evolution of these IMRIs with dynamical dark-matter distributions, but it produces a significantly smaller effect than it does in IMRIs with static dark-matter distributions. Determining the properties of the dark-matter distribution from the emitted gravitational waves, therefore, requires higher initial dark-matter densities in the dynamic case than in the static case. [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