Ayngaran Thavanesan has just completed his PhD in the Department of Applied Mathematics and Theoretical Physics. He was awarded a Bell Burnell Graduate Scholarship, and was also one of the young scientists selected for a KITP graduate fellowship from January-June 2025. He tells us about studying the very early Universe, the fascination of fundamental questions, and chasing the wonder of physics.
I study the very early Universe, a time before galaxies, stars, or even atoms existed. My work focuses on understanding the quantum physics that shaped the Universe during its birth, and how the structures we observe today, like galaxies and the cosmic microwave background, emerged from those earliest moments. These are best described by a model of spacetime known as de Sitter (dS) space.
One major idea in this area is the Wavefunction of the Universe, a concept first developed here at DAMTP by Professor Stephen Hawking and others. It’s a way of describing all the possible ways the Universe could have evolved, using the principles of quantum mechanics. Just as a wavefunction in quantum mechanics describes all possible paths an electron can take, the Wavefunction of the Universe captures all possible histories of the cosmos.
To study this, I use tools from quantum field theory and general relativity, and draw heavily on holography — a powerful idea from quantum gravity which suggests that the physics of our 4D universe (three spatial dimensions and one time dimension) might be described by a simpler, lower-dimensional theory living on its boundary, almost like a 3D hologram projected from a 2D surface. This could help us better understand the quantum nature of space, time, and gravity.
In my recent work with my PhD supervisor Professor Aron Wall and fellow PhD peer Harry Goodhew we discovered a breakthrough, which has allowed us to make progress on a major open question in the field: how to realise holography in cosmological settings.
I’ve always been fascinated by big, fundamental questions: Where did the universe come from? Why does time flow forward? What is space itself made of? When I first learned that physics doesn’t yet have a complete answer to these questions, and that it might require rethinking the very foundations of reality, I knew I had to be part of that journey. Cosmology and quantum gravity bring together many of the deepest ideas in physics, and that intellectual adventure really drew me in.
I still remember one Christmas when I was very young, my family and I were at our close family friend Maria Akka’s house for their annual Christmas dinner. My parents are practising Hindus, and they’ve always had a deep friendship with Maria Akka’s Christian family. That evening, she started teaching me about momentum, even though I was far too young to know about it at the time, but I was so excited by the idea that I kept asking her questions. She still jokes about it to this day. I guess that moment must have stuck with me, and I think I’ve been chasing the wonder of that first glimpse into physics ever since.
DAMTP is an incredibly stimulating place to work. There’s a strong sense of community, with world experts in so many areas just down the corridor, and people are generous with their time and open to collaboration. I also appreciate the culture of questioning and rigour here; your ideas are constantly tested and sharpened in discussions, which helps them grow stronger. With the hiring of new young faculty such as Professor Alejandra Castro and Professor Sean Hartnoll, it’s become an even more inspiring place to learn and do original research.
It also means a lot to me to be working in the same department where Professor Stephen Hawking spent most of his career. He has long been a hero of mine — not just for his groundbreaking scientific work, but for the resilience and strength he showed in the face of adversity. His ability to keep pushing the frontiers of physics while living with motor neurone disease has been deeply inspiring to me, especially during times when I’ve had my own challenges and obstacles to overcome. Being at DAMTP reminds me that setbacks don’t define us — it’s how we move forward that matters.
One of my favourite moments was when I realised that a symmetry principle I was exploring with Aron could explain why the universe appears to be consistent with CPT — a fundamental law of particle physics. CPT symmetry says that physical processes remain the same under three simultaneous transformations: C, charge conjugation, which swaps matter with its antimatter counterpart of opposite charge; P, parity, which flips all spatial directions as though viewed in a mirror; and T, time reversal, which reverses the direction in which time flows.
What made this moment special was that CPT invariance is usually discussed in the context of particle physics, where spacetime is fixed and unchanging. But in cosmology, the universe is expanding, so it’s not obvious that CPT should hold. After months of frustrating calculations on other projects, I started noticing a deeper pattern — and suddenly it clicked! I saw how the pieces fit together and how this symmetry could still hold in an expanding universe. That kind of breakthrough — the feeling when a hard problem finally gives way to clarity — is one of the most rewarding parts of research.
One of the things that has always drawn me to cosmology is the idea that the universe looks the same wherever you are in it. It doesn’t care who you are or where you come from — we all have the same capacity to study it. That principle has stayed with me, and I try to live it out by setting an example as a theoretical physicist working to understand the universe at the most fundamental level, and by helping others from all backgrounds do the same.
I was awarded a Bell Burnell Graduate Scholarship, which is aimed at supporting people from underrepresented backgrounds in physics. Coming from a working-class, first-generation background, I never imagined I’d be pursuing my undergraduate degree, let alone a PhD, at Cambridge. I’m also the first from my Eelam Tamil ethnic group to do so, which is deeply important to me as our community has faced decades of persecution, now increasingly being recognised as a genocide, and ostracisation.
This scholarship didn’t just provide financial support; it was a powerful statement that people like me belong in this field. It gave me the confidence and freedom to pursue ambitious research, and I’m deeply grateful for that. Representation matters, and I have done my best to help open the door a little wider for those who come after me.
I was also recently selected for a KITP Graduate Fellowship, which gave me a chance to spend several months at the Kavli Institute for Theoretical Physics in California, one of the world’s leading centres for fundamental physics. I’ve had the opportunity to work alongside researchers thinking deeply about quantum gravity and cosmology, and to exchange ideas with both local KITP and UCSB scientists, as well as the many visiting physicists who come through for the Institute’s conferences, workshops, and programs throughout the year. The KITP director and staff went out of their way to make me feel welcome and at home from the very beginning, and that warmth and support made a real difference. It’s been an incredibly stimulating and enriching environment, and I’ve learned a huge amount from the diverse KITP community.