Rencontre des groupes de travail "Formes d'onde" et "Tests de la relativité générale et théories alternatives"

Liste des Contributions

8. From Scattering Amplitudes to Classical Observables

David Kosower

04/02/2020 09:30

I outline a formalism for computing classically measurable quantities directly from on-shell quantum scattering amplitudes. I will discuss the ingredients needed for obtaining the classical result, and show how to set up the calculation to derive the result efficiently. The formalism is not specific to a given theory, and is ultimately destined to be used for general relativity. In this talk,...

3. BMS flux-balance laws

Roberto Oliveri (CEICO - Czech Academy of Sciences)

04/02/2020 09:55

Asymptotically flat spacetimes admit both supertranslations and Lorentz transformations as asymptotic symmetries known as BMS symmetries. Furthermore, they admit super-Lorentz transformations, namely superrotations and superboosts, as outer symmetries associated with super-angular momentum and super-center-of-mass charges. In this talk, we present the flux-balance laws for all such (extended)...

9. The 4PN phase of non-spinning compact objects: where are we ?

Quentin Henry

04/02/2020 10:20

The new generation of gravitational wave detectors, such as LISA, requires to have precise analytical models for gravitational wave form. These models are useful for data analysis, tests on alternative theories of gravity and comparison with numerical relativity. To this day, we know the full GW phase for non-spinning compact binary systems at the 3.5 post-Newtonian (PN) order. We now push the...

4. Scattering Amplitudes in Effective Gravitational Theories

Stavros Mougiakakos (IPhT, CEA-Saclay)

04/02/2020 11:15

Since the first detection of gravitational waves (GWs) from a binary black hole coalescence was announced in 2016, it has become increasingly pressing to provide high precision theoretical predictions for the modeling of GW templates. In this context, various methods have been employed to push the precision of the computations higher such as EOB Hamilitonian, PNEFT, Scattering Amplitudes etc....

1. New synergies between traditional PN methods and EFT: contributions of the logarithmic tails in the energy.

François Larrouturou (Institut d'Astrophysique de Paris)

04/02/2020 11:40

Combining different techniques, we derive the logarithmic contributions to the two-body conservative dynamics. Those logarithms come from the conservative part of non linear gravitational-wave tails and their iterations. Explicit, original expressions are found for conservative dynamics logarithmic tail terms up to 6PN order by adopting both traditional PN calculations and effective field...

11. Dark energy after gravitational wave observations

Filippo Vernizzi

04/02/2020 14:00

The observed accelerated expansion of the Universe opens up the possibility that general relativity is modified on cosmological scales. While this has motivated the theoretical study of many alternative theories that will be tested by the next generation of cosmic large scale structure surveys, I will show that the recent observations of gravitational waves by LIGO/Virgo have dramatic...

12. Rotating black holes in higher order theories

Christos Charmousis

04/02/2020 14:25

We will discuss an analytic rotating black hole in scalar tensor theories. The scalar gravitational degree of freedom will be related to the geodesics of the black hole spacetime.

6. A new phenomenological time-domain model of gravitational waveforms for tests of general relativity

Dr Leïla Haegel (APC)

04/02/2020 14:50

Current tests of general relativity with the LIGO-Virgo gravitational waves detections relies on using frequency-domain phenomenological models of gravitational waveforms. The design of tests varying parameters defined by their frequency can lead to ambiguity in the interpretation of the deviation measured. In this talk, I will present the first time-domain phenomenological model of...

10. EMRI waveforms for LISA via the self-force program

Bernard Whiting

04/02/2020 15:45

Among the much-anticipated gravitational wave sources for LISA are inspiraling binaries with an extreme mass ratio (EMRIs), where the mass ratio is of order 1E-3 to 1E-9, arising when a solar-massed object falls into a supermassive black hole at the center of a galaxy. Such sources are expected to be observable by LISA for up to a year before merger, resulting in more than 100,000...

2. Hairy Extreme mass ratio inspirals

Adrien Kuntz

04/02/2020 16:10

The presence of scalar 'hair' around a black hole could have signatures in the waveform produced by inspiralling objects. We propose a unifying description of hairy inspirals in the extreme mass ratio case when a single scalar field is present in the action, and we derive the dissipated power in the odd sector of the perturbations up to 3.5PN order beyond the quadrupole formula. Our formalism...

5. Mimicking black hole mimickers

Alexandre Toubiana (APC/IAP)

04/02/2020 16:35

Black holes mimickers, e.g. boson stars, are compact objects with similar properties to black holes. The gravitational wave signal emitted by a binary of such putative objects during the inspiral phase is difficult to distinguish from the one emitted by a black hole binary. Nevertheless, significant differences might appear in the post merger signal. Inspired by the known behavior of black...

7. Waveform challenges for the parameter estimation of binary black hole signals with LISA

Sylvain Marsat (APC, Paris)

The future LISA detector will enable the detection of supermassive black hole coalescences, as well as stellar mass black hole inspirals in the lower-frequency band of the gravitational waves spectrum, complementing ground-based observations of gravitational waves by LIGO and Virgo and their successors. To simulate realistically the recovery of individual source parameters by LISA, accurate...