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Kateryna Marynets

Kateryna Marynets

Born in Uzhhorod, Ukraine • Birth year 1988 • Studied Applied Mathematics at Uzhhorod National University in Ukraine • Highest Degree PhD in Differential Equations from Taras Shevchenko National University of Kyiv in Ukraine • Lives in Delft, The Netherlands • Occupation Assistant Professor in Applied Mathematics at Delft Institute of Applied Mathematics, Delft University of Technology

4 countries, 5 languages, and 1 mathematics…

Was it my big dream to pursue a career as a math professor? No, it wasn’t. In fact, when our primary school teacher asked who we wanted to become in the future, I said that I wanted to be a pediatrician. But that was only because my parents are doctors, and my grandmother was leading the children’s department in the hospital at that time. To be honest, medicine has never been my thing—but as a kid, you tend to take on the role models you see around you. And I wasn’t an exception.

Many years have passed, and mathematics and languages have become inseparable parts of my life.

In Ukraine, we say that children inherit the talents of their grandparents. And with my grandparents working in the fields of physics and mathematics, following that logic, I was probably predestined for these directions. Interestingly enough, those were indeed my favorite subjects at school. I really enjoyed solving math puzzles and diving into the laws of physics. I was extremely lucky to have great teachers who recognized my interest and kept me engaged by offering challenging problems—even though my school had a linguistic focus, and the sciences didn’t occupy much of our curriculum. Many years have passed, and mathematics and languages have become inseparable parts of my life. Those seemingly different disciplines have a lot in common: languages help in sharing my mathematical expertise to a multilingual community, and logical thinking, developed through solving mathematical problems, helps in mastering a new language.

Obtaining a PhD brought new opportunities, but it also came with a lot of pressure—pressure to deliver, pressure not to disappoint.

The path to my current position was long and quite “nonlinear”—just like the math problems I work on. In my last year of high school, I seriously considered studying international economic relations, with applied mathematics as a second option. It was the study program where I could combine my passion for mathematics and foreign languages. But in the end, I chose applied mathematics, and I’ve never regretted the decision I made.

After graduation, I was offered a teaching position at my home university, which I combined with enrollment in a doctoral program. I studied boundary value problems for systems of nonlinear differential equations and developed iterative methods for approximating their solutions. It was a great combination of analysis and work with mathematical software—something I still enjoy doing. Back then, I could conduct research at my home institution but had to defend my thesis at a different university. I still remember all those trips to Kyiv, accompanied by my parents, who helped me organize everything…I am incredibly thankful for all their patience and time that they have invested.

Obtaining a PhD brought new opportunities, but it also came with a lot of pressure—pressure to deliver, pressure not to disappoint. Since then, sports has become my first aid when I feel overwhelmed and need to change my focus during the intense periods at work.

[Fractional differential] equations are broadly used in porous media modeling and systems with memory

After graduation, and having 3 languages ‘in my pocket’, I continued teaching at my home university for a couple of years but felt an urgent need for change. I seriously considered switching to industry and even received an offer from an IT company, but something held me back. Around that time, I won an individual grant for a short-term research stay in Slovakia, where I was introduced to a new field—fractional differential equations. These equations are broadly used in porous media modeling and systems with memory. Moreover, they are able to capture more complex dynamics of a physical system in comparison to their integer-order counterparts. Back then it was still a completely unfamiliar topic for me, something I had never worked on before, but it eventually became part of my current research profile.

My time in Bratislava was a period of reflection, and it gave me the motivation to continue pursuing an academic career. I saw many opportunities that European universities offered and started applying for postdocs. Among all the negative responses and unanswered emails, there was one that changed my life. I got a postdoc position in Vienna, which I still consider my biggest achievement to date. It might sound silly but moving from Uzhhorod, that is by the way famous for its Japanese cherry blossom, to join one of the oldest and most prestigious universities in Austria was something I couldn’t have even dreamed of!

Picture of a Japanese cherry blossom

During my postdoc, I explored real-world applications of differential equations by analyzing mathematical models related to ocean and atmospheric circulation

During my postdoc, I explored real-world applications of differential equations by analyzing mathematical models related to ocean and atmospheric circulation. I was fascinated by the opportunity to apply my mathematical training to real-world phenomena, expanding my knowledge beyond purely theoretical research. As time passed and my postdoc was nearing its end, I realized I needed something more permanent. And again, I stood at a crossroads: should I switch to industry and stay in Austria with my partner, or pursue a career in academia but accept the fact that I would likely have to move to a third country within the last three years? I know many couples for whom cross-country moves didn’t work out, and in the meantime I was already fluent in German and had good chances on the Austrian labor market. Luckily, my partner was incredibly supportive, and when I got an offer from TU Delft, he did everything he could to make my decision easier.

And here we are. Five and a half years after moving, I’m now a tenured assistant professor at one of the best universities in the Netherlands, developing my own research line in nonlinear (fractional) differential equations with applications in geosciences, speaking my fifth language, and making future plans with my husband. Time has sorted out everything, and despite all difficulties I feel that I am in the right place.

Of course, at the end of the day it’s all about hard work, determination and family support —but sometimes, it’s also about that one email that changes everything in your life.

Published on April 23, 2025.

Photo credit: Kateryna Marynets

Posted by HMS in Stories
Bindi Brook

Bindi Brook

Born in Nairobi, Kenya • Studied Mathematics at the University of Leeds • Highest Degree PhD in Applied Mathematics from the University of Leeds • Lives in the UK • Occupation Professor of Mathematical Medicine and Biology at the University of Nottingham

When I think back to school days, my sense is that I’ve always enjoyed mathematics. But there is one particular memory that is contrary to that. I was around 10 years old and had been finding most of the “maths” we did quite easy. Then some combination of factors (teacher, specific content) brought a sudden loss of confidence. I could not get my head around what we were being taught and I thought that was it – that I did not like maths anymore. My dad decided I was being silly (thankfully) and worked through some examples with me, every night, for about a week. By the end of it, my temporary lack of confidence had gone and ever since then I have really enjoyed some form of maths (here one can read – NOT pure maths). In fact, whenever I couldn’t make a decision about what I wanted to do next (at the end of A-levels, at the end of my undergraduate degree) I just picked the thing I enjoyed the most (maths and then applied maths) and went with it. I come from a South Asian culture where, if you’re considered “able”, you’re expected to study Medicine. That wasn’t for me – I really did not like remembering lots of facts and much preferred the problem-solving needed for studying maths.

(…) I have started to look into the mechanisms that could lead to a rare lung disease called lymphangioleiomyomatosis (LAM) and Long Covid.

In an interesting twist though, in my research career, I have essentially specialised in applying mathematics to biological and medical problems! My PhD was all about understanding what happens to blood flow in collapsible blood vessels like the giraffe jugular vein. In my postdoc I was investigating how to optimise ventilator settings for patients in ICU and then how to deliver inhaled therapies into the lungs. Since then, my focus has been in trying to understand how diseases like Asthma and other respiratory diseases originate and then progress. This involves incorporating biology and physics into mathematical and computational models, using approaches from different areas of applied maths. More recently I have started to look into the mechanisms that could lead to a rare lung disease called lymphangioleiomyomatosis (LAM) and Long Covid.

Although I am now a Professor and have spent much of my working life in academia, I took a somewhat torturous path getting there and could have picked a different route a number of times. Immediately after my PhD I worked for a credit card company, applying statistical models in a somewhat robotic fashion. There was no problem-solving involved and within 3 months I knew I could not stay and 3 months later started a postdoc in Sheffield. Towards the end of my postdoc I had my first daughter and worked part-time to complete it after which I decided I would just take time out to look after her. Two years later I had my second daughter.

Throughout my career, I have had some fantastic mentors (both women and men) who guided me through some tough times. These included workplace bullying and discrimination (as a woman of colour) and I have had to work hard to overcome these hurdles.

When my second daughter was around 2 years old I was starting to consider alternative careers to academia (I felt I had been out of it too long, hadn’t written up my postdoc work into peer-reviewed papers, etc) when I got a phone call from a previous academic colleague from the University of Nottingham asking if I would be interested in covering his teaching part-time, as he was taking a sabbatical. I took up this offer and continued to teach and work part-time until I felt my daughters were old enough for me to consider getting back into research. I applied for and was awarded a fantastic “return-to-research” Daphne Jackson Fellowship which allowed me to restart my research on a part-time basis and also write up some of my postdoc work. I will be eternally grateful for this opportunity, as it allowed me to start my research in asthma, build up a network of collaborators and eventually my first MRC grant. The other most important thing that made all this possible is my amazing, hugely supportive, parents who helped look after my daughters for many years.

Throughout my career, I have had some fantastic mentors (both women and men) who guided me through some tough times. These included workplace bullying and discrimination (as a woman of colour) and I have had to work hard to overcome these hurdles. Unfortunately, these things still exist. More recently (in my case) these have been more in the form of unconscious bias rather than overt. And significant efforts are being made to address these issues in my School. I try to contribute the best I can with these efforts. Nonetheless, it does mean that I regularly have to sit back and ask if it’s worth it. The answer isn’t an easy “yes”, not just for the above reasons but also because of the way higher education is going these days in terms of massive budget cuts and increased bureaucracy. On the positive side, I work with wonderful friends and colleagues, on worthwhile research problems, and great students.

Posted by HMS in Stories
Liliana Esquivel

Liliana Esquivel

Born in Toledo, Norte de Santander, Colombia • Birth year 1991 Studied Mathematics at the University of Pamplona in Colombia • Highest Degree PhD in Mathematics • Lives in Cali, Colombia • Occupation non-tenure track Associate Professor at the University of Valle, Colombia

I never really thought I would become a mathematician. Although I enjoyed solving maths problems in my early years of high school, my first love was dance. I wanted to become a dancer. I finished high school when I was 14 years old. At that moment, while deciding what to study in college, a scholarship opportunity for Mathematics came up, and I thought, ‘Why not?’. That ‘why not’ has turned into a career of almost 18 years.

My passion for mathematics truly awakened with mathematical analysis. For me, the concept of approximation is one of the most refined in mathematics. Currently, I am continuing on the path that my undergraduate and graduate advisors helped shape for me. Staying on this professional path is thanks to them and the spark they ignited in me, which makes me want to keep learning every day, as learning is one of the things I enjoy the most.

Although I may have never told her, [my PhD advisor] has always been my role model in this field. My aspiration is to be a source of inspiration and guidance for my students, just as she was for me.

This career has given me the chance to visit unimaginable places, immerse myself in diverse cultures, and have unforgettable experiences. I’ve pushed myself beyond my comfort zone, tackling challenges I once believed were insurmountable, and somehow, I have succeeded each time. Along this journey, I have met incredible, inspiring, and talented individuals who have contributed to my growth both professionally and personally. Resilience and tenacity are two qualities that develop over time in this job.

I was fortunate to have an exceptional PhD advisor—an intelligent, inspiring, strong, and determined woman. Although I may have never told her, she has always been my role model in this field. My aspiration is to be a source of inspiration and guidance for my students, just as she was for me.

Being a mom has put me in the same boat as many others, trying to stay on top of my maths game while being fully present for my kids.

In recent years, my academic perspective has evolved. I wish to remain active in research, but more than teaching, I want to share my passion. My passion is mathematics—its structure, its theorems, and ultimately, its beauty. I believe that by sharing this passion, I can inspire others to appreciate the elegance and depth of mathematics. I aim to create an engaging and stimulating learning environment where students can explore, question, and develop a profound understanding of mathematical concepts. My goal is to ignite their curiosity and foster a lifelong love for the subject, just as my mentors did for me.

One of the most challenging aspects throughout these years has been balancing my professional and personal life. Being a mom has put me in the same boat as many others, trying to stay on top of my maths game while being fully present for my kids. However, being a mother to a child with special needs has illuminated for me the profound societal needs. Specifically, it’s shown me how we need a kinder, more inclusive academic world, one that’s less about labels and more about understanding and support.

Posted by HMS in Stories
Qiaoqiao Ding

Qiaoqiao Ding

Born in Linyi, China • Birth year 1989 • Studied Applied Mathematics at Shanghai Jiao Tong University in Shanghai, China • Highest Degree Doctor in Mathematics • Lives in Shanghai, China • Occupation Assistant Research Scientist

When I was a teenager, I didn’t know what maths studies would be like. But I always took every maths lesson seriously and finished all the maths homework quickly and correctly, which gave me a sense of achievement and satisfaction among peers. I was able to find regular patterns in numbers or common features, which I found very exciting. I was not a very confident girl, but maths gave me strength.

Therefore, I decided to study maths at the University. However, I did not feel like the smartest student and university mathematics was very different from high school. I felt a bit frustrated and didn’t know how to reduce or eliminate the gap. In the second year of university, computational mathematics appeared in my life, which can be regarded as the combination of maths and computer science. Using computer science to solve mathematical problems and translating computer programs into mathematics language are two main aspects. I was attracted by the variety of applications and began to pay more attention to this field in the following semesters. From my Master’s to my doctoral research, my major was always applied mathematics. I did not only choose it because of my interests but also due to the possibility to get into contact with different subjects. Even though I saw more and more women devote themselves to computer science and mathematics, I was still hesitant. Would I do as well as men, as I needed to spend more time with my family? Could I be successful in this field? Could I find my favorite job? I did my best to find the answers to these questions.

If I can solve a problem with mathematics and present the result with a computational method, I will feel very happy.

I encountered many difficulties during my PhD. My advisor is also a woman and she gave me a lot of good advice. She had published many excellent works in optimization and medical imaging and supported my own research immensely. After finishing my PhD, I applied for an academic job in Singapore and worked there for three years. During that time, my husband was working in the US. We had to conquer the difficulty of time and distance. In my opinion, family is a very important part of one’s whole life. Every researcher needs to balance work and life, especially women. In China, women play a more important role in the relationship between husband and wife, the education of children and the connection with friends and relatives. Two years ago, my husband decided to return to China and he found a position in Shanghai. Finding a job in the same city is a big problem for me. I received a lot of help and advice from my collaborators and friends.

Now, maths has become a part of my life. Everyday, I try to solve some problems using mathematics tools and try to deduce some theorem or lemma to interpret the methodology. If I can solve a problem with mathematics and present the result with a computational method, I will feel very happy. My husband works as an assistant professor of mathematics in a university and we can discuss many interesting topics together. I think I can say that maths is my job and my life.

If anyone meets any predicament, I would strongly recommend to struggle. Try it and you will find it worth it.

At this stage of my life, I know what I want, i.e., working on applied mathematics and realizing my ideas. In China, as a woman, I never felt deprived or discriminated against for working in the field of maths or programming at the university. In fact, the contrary is the case and most people I encounter admire that I work in maths and computer science. A common perception in Chinese society is that maths is the most difficult subject and only the smartest people work on the research of it. In China, in order to encourage woman mathematicians to work in academia, many policies about gender quota have been made. In many job applications, women will be preferred over a man applicant if they have the same research abilities.

I am satisfied about the path I took, and very happy I had the courage to choose maths. I used to be afraid that I would not do well. But I know I can do my best, even if I am not the best researcher. Many of the maths students I met went through the same process and most of them did not give up. I think that most of the students that choose maths will persevere in difficult situations. If anyone meets any predicament, I would strongly recommend to struggle. Try it and you will find it worth it.

Posted by HMS in Stories
Maylin Wartenberg

Maylin Wartenberg

Born in Braunschweig, Germany • Studied Math (diploma) at the Technical University in Braunschweig, Germany • Highest Degree Doctorate in Math (Dr. rer. nat.) • Lives in Meine, Germany • Occupation Professor at the Hochschule Hannover – University of Applied Sciences and Arts, Department of Business Information Systems, Field of Data Science

Analytical thinking has always been easy for me. Therefore, I enjoyed the rules and patterns that occur in math from early on. Luckily, I recovered quickly after the German high school greeted me with the minimum pass mark “adequate” in the first two math exams in 7th grade. In 9th and 10th grade, we had a very strict “old school” teacher who left a lasting impression. We always had to stand up to greet him, and if you used a swear word in class, you had to wash the glasses in the chemistry room during the next break. He was strict, but he liked me and I learned a lot. In 11th grade I spent a high school year in the US and after this year I wanted to take math as one of my advanced courses. That was a tough decision because all I did at the American high school was statistics whereas in Germany everyone had started with curve sketching. After my return to Germany, the first exam in 12th grade was about this topic. I didn’t know anything about it and I had 6 weeks of summer break to study. A former very kind teacher helped me with the material and I studied by myself and achieved a good mark. That was a major milestone to my decision to study math, since I was able to teach myself the topics of almost a whole school year. But I still wasn’t sure. Math or psychology?

After all the ups and downs you typically encounter during this phase – 3 years for me – I finished my doctoral thesis in math (graph theory) two weeks before my first daughter was born.

Both sounded very attractive to my 19-year-old self. The plans to move to Braunschweig with two of my friends were already settled and I finally chose math because it was giving me a wider range of options on what future opportunities to follow – because I had no clue what to do after my studies at that point. In the beginning we were quite a few students, but in the end only 4 of us were left in pure math – 25% women 😉. I chose most of my courses in abstract math – algebra, combinatorics – and did as little applied math as possible. I really enjoyed the study of group and ring structures and the book Algebra by Serge Lang was always by my side. I already dreamed of becoming a professor myself.

Yet, in the end, the question what to do with all the knowledge I gained crept more and more into my consciousness. That is why I didn’t pursue a strictly academic career, nevertheless I still wanted to secure the option, and chose a PHD position in business at Bosch (formerly Blaupunkt) in Hildesheim. No more group and ring theory, suddenly I had to write code in C++ for algorithms in navigation systems. I had avoided any computer science so far, thus, I was thrown in at the deep end. But I never regretted this step because I discovered that coding is not all at all as difficult as I thought – after all it’s logical – and I learned a lot about working in a bigger company. After all the ups and downs you typically encounter during this phase – 3 years for me – I finished my doctoral thesis in math (graph theory) two weeks before my first daughter was born.

I found the fitting position where I can combine my passion for analytical thinking, my academic background, and my work experience (…).

I stayed home with her and somehow managed the defence of my doctoral thesies with a 5-month-old baby and still deprived of decent sleep. After 8 or 9 months at home, my brain started asking to be challenged again, and I began to apply for jobs in industry. As a young mother I wanted to start part time, but as a woman holding a doctorate in mathematics that was not as easy to get as I hoped. After a long search, including several offers with 40 hours and more, I was finally rewarded by starting a job at VW Financial Services. My one-year-old daughter was able to stay at the company’s own childcare facility and I started with 27 hours a week as a systems analyst in the business intelligence department in IT. In almost 10 years I made my way from analyst, to project lead, to team lead all the way to head of two sub-departments and got enrolled in the management trainee program – most of this in part time including a maternity leave when I had my second daughter in between. Then, suddenly, another option which had gotten a little out of sight but was still a silent dream popped back in.

And that is my way to my current position as a professor in business computing, especially data science. I found the fitting position where I can combine my passion for analytical thinking, my academic background, and my work experience – all of that with the advantage of being my own boss, still doing interesting projects with different companies, giving talks about AI for lay audiences (schools, senior clubs, …), and guiding young people on part of their own story.

Posted by HMS in Stories
Dr Beate Ehrhardt

Dr Beate Ehrhardt

Born in Walsrode, Germany • Birth year 1987 • Studied Mathematics in Bremen, Germany • Highest Degree PhD in Mathematical Statistics • Lives in Bath, UK • Occupation Mathematical Innovation Research Associate at Institute for Mathematical Innovation, University of Bath

I am a 33-year-old applied mathematician and data analysis expert with a PhD in Mathematical Statistics from University College London. I hold a permanent, research-only position at the Institute for Mathematical Innovation (IMI) at the University of Bath. Before joining the IMI, I worked as a Senior Research Statistician at the global pharmaceutical company AstraZeneca. I have a 2-year-old daughter and am expecting my second child any day.

Growing up with two sisters and a brother, my father never told us there was a difference between boys and girls. Instead, he instilled in us an understanding that we can achieve what we want with hard work. As a result, whenever people tell me I cannot do something I take it as a challenge rather than a dead-end.

I love mathematics. I love learning. I love people. And I love science. But most of all I love when all of these four things come together. 

Ask for advice but know how to interpret it

Any kind of advice you receive from others says much more about them than about you. When I was deciding what to study after my A-levels, a teacher for advanced maths advised against “studying mathematics because it is too hard”. He was wrong. I loved every second of my undergraduate programme in mathematics. All of a sudden I was surrounded by like-minded people and could solve riddles day in and day out. Studying mathematics was the best choice for me. It was intense – and yes – it was hard work, but it was so rewarding. I learned to describe the world in equations, see the world in trends, identify patterns, and extract information from all the noise. I found a way to explain the world and found out I was really good at it! Looking back on it now, I understand that my teacher was not judging whether I would be good enough to study mathematics but rather was projecting his own experiences and difficulties studying maths. That is why I would suggest: Ask for advice but know how to interpret it.

I particularly enjoyed the statistics part of my undergraduate degree but wanted to understand further the maths behind it. So, I decided to pursue a PhD in mathematical statistics. Having been abroad to Cardiff, UK for an ERASMUS exchange during my undergraduate, I knew I wanted to be in an international environment surrounded by people from many different backgrounds and cultures for my PhD. When I heard about a PhD position at University College London on the mathematics of networks I was immediately intrigued. Before signing up, I met twice with my future supervisor, which was an incredibly good opportunity to get to know him and his team a little bit. I believe the PhD experience is strongly influenced by the research group you are joining and thus, I would very much recommend trying to find out about them as much as you can. In contrary to the common stereotype that a PhD in mathematics is lonely, I experienced quite the opposite. I joined a small research group of brilliant colleagues – some of whom I still call up nowadays to discuss research ideas, and I also was part of a cohort of PhD students that formed a support network for each other. There was always someone to discuss Maths with, or to join me for a pint when a break was needed.

(…) the very best you can do for you and your career is to discover what gets you out of bed in the morning with a smile

During my PhD, I discovered my talent for proving theorems, and there were multiple opportunities to do a Postdoc on related topics. However, being good at something does not always mean it is what you enjoy doing most. At UCL, I was fortunate to be exposed to many different types of research, which enabled me to understand that what really fascinates me are the insights one can draw from data and the corresponding impact rather than the actual tools used. So, after four years of carefully building a network and investing time and effort to build a strong foundation for a research career, I made (what felt like) a radical decision to leave academia and to join the research-end of industry where I can apply my knowledge to add insights to science with an immediate impact to the real world. Many colleagues and friends were shocked by my move including the research group I was part of, which made the decision even harder.      

Now, five years after finishing my PhD, I know it was undoubtedly the right move for me for two main reasons. First, the line between industry and academia is not as rigid as I thought. The move from a research-in-industry position back to academia is increasingly common, and the work I do now at the Institute for Mathematical Innovation is from a mathematical point-of-view very similar to my work at the pharmaceutical company. Second, and most importantly, the move enabled me to experience research in a very applied setting. Most of the work I have done post-PhD has involved engaging with multi-disciplinary teams working together towards an overarching goal. Each new project comes with its own data analytical challenges while at the same time allowing me to learn about research in a variety of disciplines. Whether it is tiny scissors that allow us to edit DNA (called Crispr Cas9) or contributing to our knowledge about the growth of black holes, the work is always fascinating. Everybody’s motivations are different and the very best you can do for you and your career is to discover what gets you out of bed in the morning with a smile.

Posted by HMS in Stories