# Caroline Jonas

PhD student in the independent research group “Theoretical Cosmology"

## What is your current position at our institute?

I'm a PhD student in the Independent Research Group Theoretical Cosmology.

## What is your academic education?

- Bachelor in Physics at Université Libre de Bruxelles
- 1 year erasmus at EPFL (Switzerland) for the first year of Master of Science in Physics
- last year of Master of Science in Physics at Université Libre de Bruxelles

## Can you please describe your research in general terms?

Since I arrived at Max Planck Institute, I have been working on the topic of quantum cosmology. We aim at describing the very beginning of the Universe, where maybe the whole space time was so small that it could be described by quantum theory (like an electron). We don't know so far any good theory of quantum gravity, so we are trying different approaches to tackle this question.

What's your favourite figure from a paper you co-authored?

This figure is taken from *Transition from inspiral to plunge into a highly spinning black hole*. This article is based on my master thesis that I did last year at Université Libre de Bruxelles in Belgium. We study the motion of a small black hole or a small neutron star around a supermassive black hole (like the one at the center of the Milky Way). The aim is to compute the gravitational waves that are emitted by this motion. This is especially relevant since the LISA mission will be able to detect them.

In particular we were working in the case where the central black hole has a very large spin, which means that it rotates around itself very quickly. This picture shows the evolution with time of the radial distance between the small body and the horizon of the central black hole. The blue curve is the adiabatic motion that had been derived previously, but was not able to describe the motion very close to the central black hole, because its assumptions were breaking down at that point. Our contribution with this paper is given by the red curve. The next step is to compute the gravitational waves generated by this motion. The ultimate goal for LISA's contributers is to constitute a whole database of gravitational waves pattern to which we will be able to compare the signal we will receive from LISA.

What was the reason you chose the Max Planck Institute for Gravitational Physics for your research?

Because I had heard of the Max Planck Institute and I was interested in Theoretical Cosmology, especially because this kind of research was not undertaken in my previous university.

Caroline Jonas' AEI homepage can be found at https://www.aei.mpg.de/person/101395.