Measuring the size of the Universe with type Ia supernova

The Universe is currently undergoing a period of rapid accelerated expansion. This discovery, suggesting that 75% of the energy budget of the Universe is unexplained represents the biggest mystery in physics today. Type Ia supernova, as bright, highly homogenous, explosions, are excellent measures of distance.

Visible to vast distances, these cosmic light bulbs are ideal measures of how the size and content of the Universe has evolved over the last 10 billion years. This PhD project will expand the use of these events to probe new aspects of cosmology.

Specifically, the project exploits data collected by the international Zwicky Transient Facility (ZTF) collaboration to maximise our understanding of type Ia supernova. We will produce a detailed 3D map of the nearby Universe and trace it's evolution over cosmic time. This project represents a leap forward in this field; more than ten thousand discoveries are now made each year, compared to several hundred collected in the last twenty.

As part of the project, we will develop machine learning tools that distinguish type Ia supernovae from other time variable sources, and search for statistical correlations between supernovae and their local environment that improve the measured distance to each event.

This project involves close collaboration with a team of international researchers in France, Germany, Sweden, Ireland and the USA, working together to measure the 3D distribution of matter which will improve our understanding of Dark Energy and General Relativity.

The next generation of transient experiments, the Legacy Survey of Space and Time (LSST), will start in 2026. This experiment will discover millions of transients in the distant Universe. The standardisation techniques and distances measured in this project will anchor the next generation of cosmological measurements, helping to explain the biggest mystery in physics.