Gravitational waves from large-mass-ratio black hole binaries
| Název práce v češtině: | Gravitační vlny z binárních systémů černých děr s velkým poměrem hmotností |
|---|---|
| Název v anglickém jazyce: | Gravitational waves from large-mass-ratio black hole binaries |
| Klíčová slova: | černé díry|gravitační vlny |
| Klíčová slova anglicky: | black holes|gravitational waves |
| Akademický rok vypsání: | 2021/2022 |
| Typ práce: | disertační práce |
| Jazyk práce: | angličtina |
| Ústav: | Ústav teoretické fyziky (32-UTF) |
| Vedoucí / školitel: | Georgios Loukes Gerakopoulos, Dr. |
| Řešitel: | skrytý - zadáno a potvrzeno stud. odd. |
| Datum přihlášení: | 01.09.2021 |
| Datum zadání: | 01.09.2021 |
| Datum potvrzení stud. oddělením: | 29.09.2021 |
| Zásady pro vypracování |
| Large-mass-ratio (LMR) black hole binaries are binary systems, where the companion of a very massive black hole is a several orders of magnitude less massive compact object, like a black hole or a neutron star. LMR can be split in two regimes: the intermediate and the extreme. In the intermediate regime belong binary systems that the ratio of the more massive object over the less one spans from hundred to thousands. The extreme regime starts from mass ratios of the order of ten thousand and ends at the order of hundreds of millions. In a LMR the smaller object follows an inspiralling motion around the more massive one due to gravitational radiation reaction, which drives away energy and angular momentum in the form of gravitational waves. Hence, these systems are called large mass ratio inspirals.
Large mass ratio inspirals systems are among the main targets of the next generation of gravitational wave detectors, both ground-based like the Einstein Telescope and space-based like the Laser Interferometer Space Antenna. Extreme mass ratio inspirals are expected to allow us to trace the spacetime around a black hole to an unrepresented accuracy. This tracing will place strict constraints on any deviation from general relativity and the Kerr hypothesis, i.e. the hypothesis that the Kerr metric describes the spacetime around a black hole. To achieve this we need quite accurate gravitational waveform templates in order to extract detailed information from the gravitational waves. Accurate waveform templates are needed also for the intermediate mass ratio inspirals. Though these systems have not been modeled sufficiently until now, there is an ongoing effort to provide such models using numerical relativity and semi-analytical approaches. To achieve the LMR modeling, in this work the effective one body (EOB) approximation will be employed as the primary tool, while a secondary tool will be numerical solutions of the Teukolsky equations. In particular, the TEOBREsumS flavor of the EOB approximation, which is currently very efficient in providing templates for comparable mass ratio systems, is planned to be expanded to the large mass ratio regime. The Teukolsky equation calculations will be performed by using an existing time-domain solver and under development frequency-domain code. During the dissertation, it might be necessary to further develop both codes. This work will begin by considering what is needed to extend the model to the LMR regime in the case of quasi-circular nonspinning binaries (i.e. binaries constituted by Schwarzschild black holes). Other dynamical features will also be possibly tackled, such as the inclusion of spins (both on the primary and on the secondary), eccentricity, precession of the spins with respect to the orbital angular momentum, orbital resonances. The final aim is to provide a good starting point for a waveform model that should be as generic as possible. |
| Seznam odborné literatury |
| Maggiore, Gravitational Waves (Volume 1): Theory and Experiments (Oxford University Press, 2008)
Teukolsky, Astrophysical Journal 185, 635-648 (1973) Buonanno and Damour, Phys. Rev. D 59, 084006 (1999) Nagar et al., Phys. Rev. D 98, 104052 (2018) Nagar et al., Phys. Rev. D 100, 104056 (2019) |