ICTP’s Postgraduate Diploma Programme was founded to help students from the developing world consolidate their skills and knowledge with a view to continuing in international higher education. Since 1991, 1167 students from a wide range of countries in the developing world have graduated from the Diploma Programme. 28 % of these came from the least developed countries in the world, and 66 Ethiopian students have studied in the programme since it began.
Raji Mamade, an Ethiopian student among the Postgraduate Diploma Programme’s latest graduates, talks about his journey into theoretical physics at ICTP, and his plans for the future.
Tell us about yourself.
I was born in the Oromia region of Ethiopia, which is 700 km away from the capital. I finished my primary school there, then I got a scholarship to a special boarding school run by a charity organization called the Oromia Development Association. Afterwards, I joined the university and studied for a double major in applied mathematics and applied physics.
How did you discover your interest in physics?
Growing up I used to like mathematics, but I always wanted to be a medical doctor. I’m diabetic, and medicine is a respected career in Ethiopia. When I finished high school, everyone expected me to become a doctor. Growing up, everyone wants to join medicine or engineering. Those are the most respected and secure careers. Also, with my diabetes, I wanted to work on endocrinology. But then, I really liked maths. I understood that my interest in medicine was just because of social pressures.
In high school, I came across a chemistry textbook with the quantum mechanical model of atoms in it. I learned that there were beta particles, which are negatively charged particles coming from inside the nucleus. So I asked my teacher how negatively charged particles could come from the nucleus. He told me that neutrons are not fundamental particles, and that there are some subatomic particles there. So, I started reading about them, and my curiosity about what's really fundamental grew.
I decided to join the physics program at university, but at the time, I didn't know much about theoretical physics. My university only had applied physics. Watching the Particle Fever documentary, which recounted the discovery of the Higgs particle 40 years after its theoretical prediction, I realised I really want to learn theoretical physics, so I started taking courses from applied mathematics and reading some foundational topics on my own on theoretical physics to fill the gaps.
In my second year of university, I talked to a professor who told me that the best direction I could go in next would be to go to ICTP. So, I was preparing for ICTP all along.
Coming from an applied physics background, how was learning about theoretical physics at ICTP?
It was very difficult for me, and intensive. At times, I was almost at breaking point, but I look back at most of my experience, how much I've learned, and how far I've come, and I thank God that I came to ICTP.
What’s your diploma thesis about?
There's this thing called AdS/CFT correspondence [anti-de Sitter spaces are used in some quantum gravity theories; conformal field theory is a special type of quantum field theory (QFT). QFT is a theoretical framework that combines classical field theory, quantum mechanics, and special relativity, and AdS/CFT correspondence is the relationship between these]. There are a lot of different directions that people take with this approach, but mainly it's used to understand quantum gravity. This correspondence is usually between strongly coupled field theory and weakly coupled gravity theory.
I'm working with Atish Dabholkar and Upamanyu Moitra on this problem. Entanglement entropy is a very useful quantity in quantum field theories and it’s difficult to calculate. A very simple formula was proposed in 2006 to calculate entanglement entropy on the gravity side, which basically reduces the involved calculation to a simple geometric calculation, like finding area or length. In my thesis, I am focusing on understanding this simple formula by deriving it from the basic dictionary of AdS/CFT correspondence and calculating entropy on both sides of the duality for specific cases.
What are the strengths of the Diploma program?
The really good thing about the ICTP environment is that it was completely new to me. New and complicated: perfect. It's like a dream for me. The program was amazing: it was immersive in terms of just understanding the courses. The professors here were very friendly. Coming from Ethiopia, I was close to my professors, but there’s more distance; there's more of a barrier back there between the students and the professors.
The most difficult course was on the standard model, but I enjoyed even the most difficult course, and I'm going to face more difficult things in the future.
What are the major challenges faced by people wanting to study theoretical physics in Ethiopia?
There's no promotion of science. It’s a poor country, so everybody who studies wants to have a good salary, help their families, and have a good life. The living conditions in my country do not let them think about having dreams, it’s more about career stability. After talking with students here, I learned that people from more developed countries know about physics from early on. I didn't have that experience. I didn't have a computer until I went to university. There were no books on popular science or physics. And on top of that, there’s a lot of pushback against people studying physics.
My mother respected my decision to apply to the physics department. She did say, “Hey, maybe you should start studying medicine,” but she didn’t push, and my brothers and sisters also attended higher education institutions and were supportive. But almost all the people I come across always wonder what happened to me. Even my senior high school physics teacher advised me against doing physics, not that he disliked physics but because he was convinced that physics has no future in Ethiopia.
What do you plan to do next?
Before I applied to ICTP, I was accepted onto the PhD programme at the Center for Theoretical Physics at the Massachusetts Institute of Technology (MIT). My mentor told me it would be a good idea to have some preparation before starting my PhD there, because the ICTP Diploma programme helps the transitions of students from developing countries to these universities.
Now, I'm going to continue working on aspects of my diploma thesis at MIT. My career plan is to stay in academia, and God willing become a good professor of theoretical physics.
I was helped by a terrific society, the Ethiopian Physics Society in North America (EPSNA) [https://www.epsna.org/mentorship-2022.html], to apply to universities. If they hadn’t helped me, I wouldn't have been able to afford the application fees and standardized exam fees. But then I came to ICTP. It's actually perfect, as I'm interested in theoretical physics and also in science promotion. I feel indebted to all the institutions who work on promoting science as I have been helped by them starting from high school, and it’s also a dream of mine to pay it forward. I want to give back to my country by promoting science there. Next year, when I’m at MIT, I will start mentoring students, and giving lectures at summer schools with the EPSNA in Ethiopia.