Anna Puecher, PhD at Nikhef, will defend her thesis Wednesday 7 February 2024 at 16.15 at the Utrecht University.
“Fundamental physics with gravitational waves – Testing general relativity and studying neutron stars with current and future detectors”
Since their prediction in Einstein’s theory of general relativity, gravitational waves took a hundred years to be actually detected. Nevertheless, the wait was well rewarded since measuring gravitational waves did not only provide a strong confirmation of the predictions of general relativity, but also offered a new way to study fundamental interactions. The information extracted from gravitational wave signals allows us to probe the theory of general relativity in the strong-field regime, as well as to study the equation of state describing the extremely dense matter inside neutron stars.
In this thesis, we investigated both these aspects. In particular, we developed a method to probe general relativity by looking at the amplitude of subdominant modes. On the other hand, we constructed a model that describes the gravitational wave signal emitted during the full coalescence of a binary neutron star system, including the post-merger, and we employed it in parameter estimation analyses.
We also turned our attention to next-generation detectors, which are expected to increase sensitivity and extend the detection bandwidth compared with current detectors, both at lower and higher frequencies. We studied how this will improve our post-merger analysis, but also the measurements of the system’s parameters from the inspiral part of the signal only. In particular, for the latter, we investigated how the different designs proposed for the Einstein Telescope will affect such measurements.
The high sensitivity of future detectors, however, comes also with downsides: the computational cost of the analyses will increase, thus it is necessary to find alternative techniques in order to make the analyses feasible. Furthermore, the high precision with which we will be able to measure the sources’ parameters will enhance the effect of systematic errors, e.g. induced by the waveform models employed to analyse the data. Therefore, we analysed some of the gravitational wave events in the latest catalog with different waveform models, in order to identify possible preferences among the models and, consequently, highlight potential systematics.
“Fundamental physics with gravitational waves – Testing general relativity and studying neutron stars with current and future detectors” (pdf)
The PhD defense will take place in the Academiegebouw, Domplein 29, 3512 JE Utrecht.
More information and livestream link on the website of the Utrecht University.
Supervisor: prof. dr. C.F.F. Van Den Broeck
Co-supervisor: dr. S.E. Caudill
Contact: Anna Puecher