Meet **Audace Amen Vioutou Dossou-Olory** in this Q&A series with 6 out of 200 computer scientists and mathematicians participating in the 5th Heidelberg Laureate Forum, September 24-29, 2017. 26 Laureates (Abel Prize, Fields Medal, Nevanlinna Prize, Turing Award and ACM Prize in Computing) will attend the forum together with them. For a full week, Heidelberg in Germany will be the hot spot of mathematics and computer science.

**What is your name and nationality? **My name is Audace Amen Vioutou Dossou-Olory, and I am from Porto-Novo in Benin.

**Where did you study and where are you currently based? **I obtained my undergraduate degrees in Benin from both Universit ́e d’Abomey-Calavi and Ecole Polytechnique d’Abomey-Calavi before moving to the African Institute for Mathematical Sciences (AIMS) in South Africa. I am now affiliated to Stellenbosch University.

**What is your current position?** I am a PhD student in the Mathematics Division at Stellenbosch University (South Africa).

**What is the focus of your research? What is your research project?** Our research focuses on understanding the asymptotic relation between subtree densities. Apart from being a formal object of study for combinatorists, trees are commonly used by computer scientists in the analysis of algorithms and by biologists in modelling real-life processes, for example, to visualise how different species are evolutionarily linked. In organic chemistry, trees function as molecular graphs of acyclic organic molecules, describing molecules and molecular compounds.

A typical question is how large can be the number of appearances of a given tree in a tree with more than one million number of vertices. This question is the underlying problem that leads to the research we are currently undertaking. We are mainly developing formulae for computing this graph parameter for as many as possible classes of trees.

Although my PhD topic is mostly theoretical, it turns out that it is related to mathematical biology. For example, when drawing a tree with the root at the top, non-leaf vertices can represent events of fission in which new species are created, and so the leaves will represent the final species. This type of tree is well-known to biologists in the evolutionary history analysis of a group of species. In our research, we also intend to derive possible generalisations of this parameter for trees with given restrictions, such as the degree sequence, the number of leaves, etc.

**Why did you become a mathematician?** My motivation went back to early high school when I was taught plane geometry. From there, I decided to study mathematics because I want to learn a new language as well as a new way of thinking. Everything in the universe has a mathematical systematic. More than tools for solving problems, mathematics courses develop intellectual maturity and also help to visualise abstract concepts.

At university, although I was admitted with a scholarship into engineering studies, I also enrolled into a parallel program in mathematics because that is what I wanted to do. With dedication and determination, I graduated in both: pure mathematics and design electrical engineering. After obtaining my basic training in Benin, I was fortunate enough to be selected for the structured masters program at African Institute for Mathematical Sciences (AIMS) South Africa. At AIMS, I was trained very well in mathematical methods, mathematical reasoning and scientific rigour.

**What do you see yourself doing in 10 years?** My vision is to join the next generation of top mathematicians, work with industry to address real problems and become a leader in academia and/or industry. My long term dream is to impact society through my knowledge in mathematics and science in general.

**What are you doing besides research?** I am a teaching assistant for different mathematics subjects where my responsibilities include tutoring and marking examinations. For my professional development, I am active in various social extra activities such as music and traditional dances. Sometimes, I also spend some happy and enjoyable moments ranging from hiking to playing games such as soccer with my friends in the university.

**Why did you apply for the HLF?** Interacting with scientists from diverse multicultural societies from across the world who have demonstrated a consolidated understanding of mathematics and computer science with the highest possible prizes is a great opportunity to be seized. I believe that I will also improve my abilities to explain difficult issues in a structured and easy to understand way, which is an excellent trait for a future academic.

**What do you expect from this meeting?** I will surely benefit from attending the HLF – Apart from meeting and engaging into discussions with laureates, for my part, I will also attend the workshop entitled “The moving frontier between informatics and mathematics”, a topic which is of interest to me because it has connections with my present PhD research project. Moreover, it is much more practical and therefore of more use for my future career.

**Which laureates present at the forum would you really like to talk to?** I cannot wait anymore to meet Sir Andrew John Wiles (proof of Fermat’s Last Theorem) and Efim Zelmanov (solution of the restricted Burnside problem). Thinking in numbers by entering into a completely abstract world is something pretty amazing that Number Theory actually does. Sir Wiles tackled the Fermat’s Last Theorem from the algebraic point view by proving a related conjecture that settled this theorem. Beyond curiosity, my basic knowledge of group theory also leads me to engage discussions with Zelmanov and surely I will learn valuable skills from it. In general, I would like to get the story on their paths to professionalism. I strongly hope it will prove to be an inspiring session with them sharing with me about their journeys as a scientist.

**When describing your research to non-experts, what do you find most challenging?** Frankly speaking, it is always hard to explain a research of a purely theoretical nature in layman’s terms and where in life it “fits in”. Enabling the non-expert to understand the jargon is the most challenging part, but it is doable.

6 out of 200 – Audace Olory is making sense of trees was published first on Heidelberg Laureate Forum.