What is your name, affiliation, academic position, and job title?
Richard I. Anderson, currently assistant professor at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland.
What is your journey?
I am originally from a small town in Germany and got my physics degree from the Georg-August-University in Göttingen after having spent 1 ½ years abroad studying and exploring different research internships in Sweden, Taiwan, and Canada. In my professional career, I have lived in Switzerland, the United States, and Germany.
What is your field of research and/or what project are you involved in?
My initial training is that of a stellar astrophysicist. However, I became increasingly interested in distance measurements and the expansion rate of the Universe (Hubble constant) during my fellowship at Johns Hopkins and am now pursuing a very accurate measurement of the Hubble constant. More specifically, I focus on stars that can serve as so-called standard candles to determine distances inside the Milky Way and out to a few hundred million light years. These stellar standard candles calibrate the type-Ia supernova explosions that we use to measure the Universe’s expansion with greatest accuracy. I focus on everything from the physics of these stars to how we can faithfully measure distances with them.
Briefly describe your career trajectory to date. What positions have you held, when and where?
I obtained my PhD from the University of Geneva in Switzerland before moving to the Johns Hopkins University in 2014 on a Swiss NSF postdoctoral fellowship. In 2017, I moved to the European Southern Observatory in Garching near Munich, Germany, as an ESO fellow. Thanks to grant funding from the European Research Council and the Swiss National Science Foundation, I moved to EPFL in 2021 to launch my own research group.
What are your research plans?
The main goal of my research is to measure the expansion rate of the Universe today with the greatest possible accuracy. To this end, I focus on improving the precision of distance measurements, study the systematics of distance measurements, and work to improve the understanding of the stars we use to make these measurements.
How does CosmoVerse fit within those plans?
The CosmoVerse COST Action provides an excellent framework for understanding our results in a cosmological context and offers many opportunities to exchange with cosmologists and others involved in related measurements. The interdisciplinary nature of this result renders these exchanges particularly precious.
Which of your skills are you most proud of, or find most useful?
My resourcefulness that allows me to tackle new problems.
What new skills would you like to learn in the next year?
I’d like to learn more about neural networks and how artificial intelligence can help us make the most of the wonderful data we are collecting.
What are the most exciting open questions in your research area?
What does the discord between the directly measured value of the Hubble constant and the value predicted by cosmology based on the echo of the big bang tell us about the Universe and how it evolves? Also, what are the main limitations for measuring distances to better than 1% accuracy?
What advances or new results are you excited about or looking forward to?
The new James Webb Space Telescope (JWST) observations of supernova host galaxies have recently provided a conclusive test of one of the principal systematics of the Hubble constant measurement, rejecting the blending of stars (“crowding”) as the origin of the Hubble tension at very high significance.
Additionally, we recently made interesting progress towards improving distance estimates based on the Tip of the Red Giant Branch (TRGB) method. Improving the TRGB holds particular promise in the era of the JWST. As it turns out, the variability of stars near the TRGB has much to tell us about these stars and distance measurements, and this variability has only recently been considered.
What is your view on cosmic tensions? How does your work connect with this open question in the community?
The cosmic tensions we are discussing in CosmoVerse arise because increasingly better measurements provide stronger and stronger tests of our current understanding of the Universe. It is quite natural that this understanding is limited to some degree, and so it is also natural that tensions eventually arise. My approach is to make sure that our measurements, which do not require knowledge of cosmology, are as accurate as possible. In this way, we can obtain the strongest and most informative tests of cosmology and perhaps even help guide the way to a paradigm shift that would change our understanding of the Universe and its evolution. Given that the tensions have risen with ever improving measurement quality, I am optimistic that we stand to learn something really important!
In your career so far, at what point were you the most excited, and what were you excited about?
Just prior to starting my first position at EPFL. I had previously been an independent researcher, but this move marked a significant career evolution for me to becoming a group leader. Working with my students and postdocs is incredibly enriching and deeply satisfying, and every day I look forward to meeting with them.
What is the biggest obstacle that is slowing down your research field right now?
The intense competition for observing time on the leading space-borne facilities, notably the Hubble and James Webb Space Telescopes. Additionally, we need a larger optical space-based telescope to detect Cepheids in distant galaxies. However, such a new infrastructure is not currently planned.
What role do you think a community network like CosmoVerse can play in developing theoretical astroparticle physics and cosmology?
I see two main ways CosmoVerse can do that, both of which rely on bringing people together. First, CosmoVerse connects communities across the typical boundaries of research fields. Second, it improves equitable access to collaborations and other forms of interactions between scientists across Europe. In this way, CosmoVerse can generate new ideas and provide the needed impetus for considering new approaches to astrophysics and cosmology.
What do you like and dislike about being a scientist?
I love the intellectual freedom, and I dislike the existential threat of non-permanent positions.
What’s your favourite food? Why?
Sauerkrautpizza. But please do not try this at home.
Your favourite scientist and/or science fiction film?
Dr. Emmet Brown and Back to the Future.
How do you relax after a hard day of work?
What is that word?
What non-physics interests do you have and want to share?
I am fascinated by people – and I love being a parent.
If you were not a scientist, what do you think you would be doing?
Hopefully something useful, perhaps as a politician or trial lawyer.
What do you hope to see accomplished scientifically in the next 50 years?
An actionable solution to the climate crisis.
In your view, what’s the most important challenge that humanity faces currently?
The climate crisis, the changing balance of power in the world, and the dissolving boundaries between fact and fiction.