Name: Andrew Taylor
Current position: Faculty
Affiliation: DESY
Field of research: Theoretical Astroparticle Physics
What is your career trajectory to date?
I did my undergraduate and PhD at the University of Oxford. After that I went to do Postdocs at the MPIK in Heidelberg and the University of Geneva. Following this, I got a Schrödinger fellowship for 5 years at DIAS in Dublin.
What are the most exciting open questions in your research area?
Simply put- how nature seems to accidentally build such efficient particle accelerators. The phenomena of particle acceleration in astrophysical objects now seems somewhat ubiquitous. This in itself was unexpected. However, the underlying question as to why the process appears to operate so effectively seems deep, and demands a better understanding of these astrophysical systems whose underlying physics is described by magneto-hydrodynamics.
What do you like and dislike about being a scientist?
I really enjoy having my daily thoughts focused on simple underlying questions which engage me. This freedom to ponder coherently on questions for relatively long time stretches of time is a real luxury. What I dislike is the endless noise of modern life, which appears hell bent on distracting my attention.
Which of your skills are you most proud of, or find most useful?
I believe that I am rather good at estimating the magnitudes of physical quantities quickly in order to get a feel for the relevant physics at play in a physical system. I have attempted to nurture this skill since my PhD days, since I finished my undergraduate studies frustrated that I didn't have much physical intuition for describing physical systems.
In your career so far, at what point were you the most excited, and what were you excited about?
In 2018 and 2019, through my involvements in the HESS gamma-ray detector, I became very excited by our detection of very high energy gamma-rays (exceeding 1 TeV in photon energy) from the afterglow of two gamma-ray bursts. What was surprising about these detections was that they were achieved a longer time after the initial prompt emission from the gamma-ray burst. During these late times, the gamma-ray flux at very high energies was expected to be exceedingly low, so their relative brightness and the hardness of their spectral emission, both came as a great surprise. Indeed, it seems likely to me that we still do not understand aspects about the nature of this emission, even now several years after their detection.
What new skills would you like to learn in the next year?
I am rather weak at learning foreign languages. In the coming year I would like to improve my understanding and ability to utilise German grammer.
What advances or new results are you excited about or looking forward to?
It appears to me that we are presently enjoying a growth in rapid observational results challenging our understanding of particle acceleration at fast (mildly relativistic) shocks. I believe that these observational advances offer new insights into the origins of the highest energy cosmic rays that we detect arriving to Earth. It is this observational input, and the theoretical insights provided, which excite me and keep optimistic that the origins of these particles may soon be found.
What is the biggest obstacle that is slowing down your research field right now?
I see an inertia of ideas in some areas of high energy astrophysics which appears to me unhealthy. For some time in my field, theoretical ideas have been put forward which were not put to rigorous testing by observation. Only now in this recent age of observational probes of these ideas can we start to separate theoretical speculation from theoretical success.
What role do you think a community network like EuCAPT can play in developing theoretical astroparticle physics and cosmology in Europe?
I think that a sense of European-wide identity in theoretical high energy astrophysics has long been needed. Given the global challenges being faced, having a strong community on our doorstep to interact with and benefit from it particularly important. I see the role of EuCAPT being to nurture and develop this European-wide community.
What’s your favorite food?
This is too time-dependent to allow a meaningful answer.
Have you lived in a different European country than you do now? If so, would you like to tell us something about it, e.g. a fond memory or something you found surprising?
Having had both my children born in different European countries was interesting and enlightening.
How do you like to relax after a hard day of work?
I like to go running in the evening to clear my head.
What question would you have liked us to ask you, and what would you have responded?
It would have been nice to have been asked which scientists inspire you in your daily research. If asked, I would have indicated that the biographies I've read on Michael Faraday and Enrico Fermi have both strongly influenced the type of scientist that I continue to try to myself develop into.
Name: Ottavio Fornieri
Current position: Postdoc
Affiliation: Gran Sasso Science Institute
Field of research: Cosmic-ray acceleration and propagation theory
What is your career trajectory to date?
I did my Ph.D. in Theoretical Physics within a joint project between Italy and Spain, earning my doctoral title in 2021. Before ending it, in December 2020, I moved to DESY Zeuthen as a Research Associate, until September 2021. I am currently a Postdoctoral Researcher in Gran Sasso Science Institute, in L'Aquila (Italy).
What are the most exciting open questions in your research area?
1. The propagation of cosmic rays in our Galaxy is still up to debate. The overall picture is agreed upon: diffusion is likely the result of charged particles scattering off turbulent magnetic fluctuations. However, various insights from plasma physics suggest that what were earlier thought to be the scattering centers for cosmic rays are probably not efficient enough. Therefore this made the cosmic-ray propagation process a widely open question. 2. Another exciting problem is how cosmic rays are get accelerated up to PeV energies, in light of the recent evidence coming from dense star forming regions.
What do you like and dislike about being a scientist?
I need the pleasure of the discovery, the whole investigation process that leads to all the pieces of a puzzle to match up together. I sometimes dislike the (mostly unhealthy) competition among groups that should be operating towards the same achievements.
Which of your skills are you most proud of, or find most useful?
I am good at digging very deep into a specific problem, until I can comprehend it under different perspectives that, at the beginning, seemed to be unrelated to each other.
What new skills would you like to learn in the next year?
I would like to learn how to run and analyze plasma-turbulence simulations (MHD/Hybrid).
What advances or new results are you excited about or looking forward to?
I am studying to understand the physics of propagating magnetic fluctuations in the plasma - which modes can propagate, their potential damping mechanisms, etc.
What is the biggest obstacle that is slowing down your research field right now?
Learning numerical techniques.
What role do you think a community network like EuCAPT can play in developing theoretical astroparticle physics and cosmology in Europe?
I think it is of outstanding importance to bring together people who, on the other hand, are used to compete. Science is not a competition.
What’s your favorite food?
Arrosticini!
How do you like to relax after a hard day of work?
I love listening to live music in a pub. I read a lot and go to the cinema.
Do you have any non-physics interests that you would like to share?
Cooking.
If you were not a scientist, what do you think you would be doing?
I would have liked to be a historian, probably.
What do you hope to see accomplished scientifically in the next 50 years?
The origin of UHECRs is one open question that seems to be solved in the next years.
Name: Paul Frederik Depta
Current position: Postdoc
Affiliation: Max-Planck-Institut für Kernphysik
Field of research: Dark matter, connections between particle physics and cosmology
What is your career trajectory to date?
I studied physics at the University of Frankfurt, Germany, where I obtained my Bachelor’s and Master’s degrees in 2015 and 2017. Between 2018 and 2021 I was a PhD student in the DESY Theory Group in Hamburg, Germany. Since 2021 I am a postdoc at the Max-Planck-Institute for Nuclear Physics in Heidelberg, Germany.
What are the most exciting open questions in your research area?
What is the nature of dark matter? Where and how should we look for it? What could be new observational signatures of dark matter?
What do you like and dislike about being a scientist?
I like the opportunity to work on interesting problems and that by doing so, we are actually generating new knowledge in an effort to describe the physical world. At the same time, I dislike some of the frustrations along the way, be it in setbacks (though they are certainly part of the process) or uncertainties as a young scientist.
Which of your skills are you most proud of, or find most useful?
I am proud that I have the resilience to work on difficult problems and eventually solve them. This is also a very useful skill.
In your career so far, at what point were you the most excited, and what were you excited about?
It’s difficult to choose from a couple of moments, but putting my first paper on the arXiv was certainly a very exciting moment for me.
What new skills would you like to learn in the next year?
I would like to learn more about cosmological perturbation theory and applications for different dark matter models.
What advances or new results are you excited about or looking forward to?
I am looking forward to finding out more about/discovering the nature of dark matter. But I am also excited for other new results and believe that we will have interesting advances at the interface of particle physics and cosmology (e.g. in gravitational waves, 21cm observations, etc.).
What is the biggest obstacle that is slowing down your research field right now?
I think the combination of both, a wealth of data supporting the Standard Model of particle physics as well as the lack of data hinting at new physics beyond the Standard Model, is a difficult situation for a theoretical physicist working on dark matter to make progress right now.
What role do you think a community network like EuCAPT can play in developing theoretical astroparticle physics and cosmology in Europe?
A community network like EuCAPT helps to provide opportunities for scientific discussion and exchange, in my opinion probably the most important basis for developing theoretical astroparticle physics and cosmology in Europe even further.
What’s your favorite food?
Pasta.
How do you like to relax after a hard day of work?
I relax by playing the trumpet.
Do you have any non-physics interests that you would like to share?
I really enjoy playing the trumpet, which I do in different orchestras and ensembles. I also like cooking.
If you were not a scientist, what do you think you would be doing?
I think I would play the trumpet in a professional orchestra.
What do you hope to see accomplished scientifically in the next 50 years?
If I have to pick just one goal, I would say to unveil the nature of dark matter. But I do hope that we solve some other problems too, like the origin of the baryon asymmetry in the universe, the origin of neutrino masses, the nature of dark energy, and others.