Alex Jenkins

I'm a theoretical physicist, working at the interface between cosmology, high-energy physics, and quantum matter. My research looks at new ways of probing the fundamental laws of Nature, whether that's using gravitational waves as cosmic messengers, or using quantum technologies to simulate the early Universe.

I'm currently based at the University of Cambridge, where I hold the Gavin Boyle Fellowship in Cosmology at the Kavli Institute for Cosmology (KICC) and the Department of Applied Mathematics and Theoretical Physics (DAMTP). I am also supported by an EPSRC Stephen Hawking Fellowship, and am a Fellow of Selwyn College.

Much of my current work focuses on vacuum decay, a fascinating quantum-mechanical phenomenon that is a ubiquitous feature of early-Universe cosmology. As a member of the Quantum Simulators for Fundamental Physics (QSimFP) Consortium, I am helping to develop laboratory experiments that will empirically test our understanding of vacuum decay for the first time. These experiments could have important and far-reaching implications for areas ranging from inflation and the multiverse to the stability of the Higgs field.

Another key focus of my research is gravitational-wave astronomy. I am particularly interested in using gravitational-wave observations to probe cosmology and fundamental physics, for example by searching for signals generated in the very early Universe, or by using gravitational-wave sources as tracers of cosmic structure formation. In 2023 I was awarded a Buchalter Cosmology Prize (2nd prize) for my work on detecting gravitational waves via their effect on binary systems. I am now part of an international team of 40+ scientists developing the GUEST mission concept (Gravitational Universe Exploration with Satellite Tracking), which will use these ideas to search for microhertz gravitational waves, ultralight dark matter, and deviations from general relativity.

I'm a core organiser of CamGW, an interdepartmental network for gravitational-wave researchers in Cambridge. I'm also a co-organiser of GW:UK, which plays a similar role on a national scale, connecting gravitational-wave researchers across the UK.

I was previously a Postdoctoral Research Fellow in the Cosmoparticle Initiative at University College London (2021-2024). I did my PhD in Theoretical Physics at King's College London (2017-2021), and my MA and MSci in Astrophysics at the University of Cambridge (2013-2017).