Exploding stars, or supernovae, are important probes of the extragalactic universe, from finding the lowest metallicity environments, to studying the large-scale dynamical effects of dark energy. However, many aspects of supernovae as a population of events remain unclear, including the variety of supernova types, their luminosities, and their progenitor stars. This project will use data from two large, recently-completed surveys of supernovae - the Dark Energy Survey and the OzDES survey - to probe and understand the statistics of the supernova population. These data, on thousands of supernova explosions, will be the first census of the high-redshift explosive transient population, with a particular focus on the diversity of the core collapse supernova population. These results will then be used to prepare for two major new facilities that will revolutionise the study of supernovae. The first is the Large Synoptic Survey Telescope (LSST), an 8-m survey telescope that will image the whole sky every 2-5 days, and which will find new supernova explosions at an unprecedented rate. The second is the ESO 4MOST multi-object spectrograph, which will study thousands of supernova explosions and their host galaxies in great detail as part of its TIme Domain Extragalactic Survey (TIDES). Our project will provide the data needed to optimise these two experiments, enabling us to ensure that the combination of facilities will provide the ultimate cosmological sample of type Ia supernovae, and probe completely new parts of time-domain parameter space.

The project will explore fundamental open questions in high-energy theoretical physics using cutting edge techniques from quantum field theory.

How did life begin on Earth? While disagreements remain, one thing for certain is that the first life needed water, a source of energy and non-biologically made organic compounds; and the best candidate for the first life was a microbe. To find these on early Earth, the best place to look would be where water met unreacted rocks from the Earth's interior. Mantle rocks called peridotites, normally residing >6 km below the seafloor or 40 km below land surface, could be brought to surface by overthrust along plate boundaries due to plate tectonics. These peridotites are a reservoir of reduced metallic components, especially iron, which react with water when exposed to form gaseous hydrogen (H2). This then triggers a series of spontaneous reactions that release energy and turn carbon dioxide (CO2) into bicarbonate and methane (CH4), and other simple organic compounds. These reactions, collectively known as 'serpentinisation', thus provide the ideal setting for the emergence of life. Today, these occur in low-temperature hydrothermal systems on the seafloor, or in 'ophiolites', ancient ocean crust and upper mantle that got uplifted on land such as that found in the Sultanate of Oman. These are likely the best modern analogues of the first cradle of life. Many studies have been conducted to date using these systems to try to understand how the biosphere has been evolving on Earth and perhaps on other planets. Missing in all these investigations, however, is the source of nitrogen (N), the key element used to make DNA, enzymes and proteins. Biological growth in many ecosystems today is limited by the availability of N. Although substantial amounts of N have been present in the atmosphere as gaseous N2 since early Earth, for life to use this N the strong triple bond of N2 has to be broken, and it takes considerable energy. N could also have come as nitrite (NO2) and nitrate (NO3), but both first had to be made by lightning from atmospheric N2, and then rained into the ocean before coming in contact with exposed mantle peridotites. Recently, rock analyses have found that ammonium (NH4+) sometimes replaces certain metals (e.g. potassium) in minerals such that the solid Earth holds ~7 times the N as the atmosphere. Hence, if life can tap into this immense N source, the early biosphere would not be N-limited. On the other hand, N can exist in several forms of varying electrochemical potentials, and so its many transformations can occur spontaneously with other chemicals to generate energy to support life. Most notably, NO3 is the first-choice alternative used for breathing (respiration) when oxygen runs out, thereby burning 'food' (organic carbon) into CO2 to obtain the necessary energy for life metabolisms. Meanwhile, some microbes may harness the energy from the reactions between NO2 and NH4+ or CH4 to make their own food from CO2, akin to plants performing photosynthesis but with chemical energy instead of sunlight. Therefore, as various N-forms are present in modern subsurface serpentinising systems, various N-transformations may occur to power the microbiome within. The activities of these reactions and their impacts on the environment have never been assessed, nonetheless. This project seeks to examine how subsurface biosphere acquires N, and how subsurface N-cycling operates and interacts with the subsurface biosphere in a serpentinising system. We will use the rare heavy form of N -15N- to track N-transformations by microbes, and 15N-content in rocks and fluids as tracers, combined with state-of-the-art bioimaging and gene expression, to assess how microbes obtain their cellular N, and to what extent N-transformations are 'actively' powering subsurface life. We will use the Oman ophiolite, the world's largest, best exposed block of oceanic crust and upper mantle as a model active serpentinising system, given its easy access and the newly drilled deep boreholes and drill cores made available by the Oman Drilling Project.

This PhD brings together advanced ultrasonic technologies [1] with expertise in remote monitoring of the marine environment to develop a novel system for the autonomous monitoring of phytoplankton. The interplay between engineering and ocean science requires enthusiasm to work across a range of disciplines. Monitoring populations of phytoplankton is crucial for understanding, protecting and managing the health of marine and freshwater environments, and identifying risks to human health from bio-toxin-producing species. Existing technologies typically require sampling, often from remote or hazardous environments, lengthy sample preparation and laborious analysis methods to identify and quantify species, and there is high demand for new commercial systems that address these issues. There is particular need for this type of technology in coastal waters where blooms of toxic algal species cause mass mortalities amongst marine life and threaten public health. The PhD will develop a novel ultrasonic technology to focus thousands of phytoplankton cells into the imaging plane of a camera system. Coupled with a computer vision system, this will open the possibility of an imaging cytometer that can be deployed in a wide range of environments using state of the art marine autonomous systems including unmanned surface vehicles (USVs) and Autonomous Underwater Vehicles (AUVs).

Optical fibres have transformed our modern world. They form the backbone of our telecommunication network and have enabled high power lasers used in manufacturing. There is a huge amount of technology that is now possible due to the development of the optical fibre. This project seeks to develop a manufacturing approach for the next generation of optical fibre. Rather than a single flexible strand of glass, we look to manufacture flexible glass sheets. These glass sheets will have similar properties as current optical fibre but the additional width dimension will allow new technology to be realised. For example, the glass sheet can be internally structured to manipulate light. Applications of this ability would include next generation of augmented reality eyewear, quantum computers, telecommunication infrastructure and new potentially higher power lasers. This technology could be transformative for communications, computation and engineering sectors.