2022 Highlights

DiRAC resources used: COSMA8 A new understanding of the “canonical” model for Moon formation was provided by Kegerreis et al (2022). Our paper showed that a Moon-sized body can be immediately placed into orbit following the collision of a Mars-sized body, called Theia, with the proto-Earth. Previous low resolution…

Dr Adrian Barker University of Leeds Here are a few science hightlights since our project started on 1st April 2022. Neutron stars are the strongest magnets in the Universe. Their extraordinary magnetic fields are formed during the supernova explosion and continue evolving when neutron star crust solidifies. Magnetic fields…

Contrary to the standard lore, there is mounting observational evidence that feedback from active galactic nuclei (AGN) may also play a role at the low-mass end of the galaxy population. We have explored this possibility with a series of high-resolution zoom-in simulations, varying the AGN prescription and supernova energetics.…

Figure 1: The topological charge distribution of one of the new two-flavour configurations. This image was selected as the winner in the Particle and Nuclear Physics category of the DiRAC 2022 Research Image Competition. Nearly-conformal gauge theories have been singled out as potential avenues for new physicics that can…

PI: Hayley J Macpherson In cosmology we typically simplify the dynamics of the Universe via the assumption of a homogeneous and isotropic expansion of space-time. While such an assumption is extremely useful and necessary in most application, the dynamics are realistically more complicated. The existence of the large-scale structure…

Exoplanets form in cold discs of gas and dust around young stars. Our long-standing picture of these so-called protoplanetary discs is that all the planet-forming material orbits in a single plane (as with the planets in the Solar System). However, recent observations with the Hubble Space Telescope, the ESO…

Axion-like particles (ALPs) are a candidate for dark matter, the elusive ‘missing mass’ of the universe, inferred by it’s gravitational presence in galaxies, clusters and cosmological structure formation. As a dark matter candidate, ALPs are preferred by theorists since they are a model independent generalisation of the standard model…

Understanding the nature of the Standard Model Higgs boson is still an open problem. Extensions of the Standard Model in which its fields have a composite origin provide a compelling first-principle explanation of the existence of the Higgs boson and explain its mass in terms of spontaneous breaking of…

DiRAC Project dp162/PPSP311, “Lattice studies of 3d super-Yang–Mills and holography”, is using the Cambridge icelake cluster to explore conjectured holographic dualities that relate supersymmetric quantum field theories to quantum gravity in a higher number of space-time dimensions. Such holographic dualities are widely employed in theoretical physics, and are beginning…

One of the key factors determining galaxies’ observable properties, such as their morphology and colour, is their angular momentum. However, the origin of this angular momentum remains uncertain. Observations reveal that the spins of neighbouring galaxies are correlated one with another, a signal known as the intrinsic alignment signal.…

The gravitational potential of DM halos facilitated the formation of the coolant H2 within baryonic gas, allowing it to cool and collapse. The evolution of the collapse is dominated by the chemistry involved. The dominant chemical processes that complicate the collapse are three-body H2 formation heating, collision-induced emission cooling…

A science highlight in 2022 was the development of the first hydrodynamical simulations of the intergalactic medium (IGM) to incorporate heating by dark photons.  Photons are the mediator of the electromagnetic force between charged particles, such as electrons and protons. We expect particles in the dark sector to interact…

The Banks-Fischler-Shenker-Susskind (BFSS) model is one of the popular microscopic models of black hole dynamics, capable of explaining how black holes scramble information. Studies of the BFSS model suggest that a microscopic mechanism of information scrambling by black holes is related to their intrinsically chaotic dynamics. In particular, BFSS…

PI: Anastasia Fialkov Filamentary network in FDM. Figure from Dome et al. 2023b. The fuzzy dark matter (FDM) scenario has received increased attention in recent years due to the small-scale challenges of the LCDM cosmological model and the lack of any experimental evidence for any candidate particle. In this…

PI: Simon Hands Institution: University of Liverpool The Thirring Model describes relativistic fermions moving in a two-dimensional plane and interacting via a contact term between conserved currents. The physical system it most resembles is low-energy electronic excitations in graphene. For free electrons at half-filling on a honeycomb lattice, conduction…

Project: dp134Author: Ben Morton (morton@roe.ac.uk)Team members: Prof. Sadegh Khochfar, Dr. Jose Onorbe Dynamical friction is the process by which a massive perturber, moving through some background medium, gravitationally interacts with that medium, producing a net retarding force to its motion. When the background medium is gaseous, the pressure forces…

This is a 3D high resolution (10243) hydrodynamics simulation of a type-II supernova explosion using the code AREPO. The outer boundary seen is the forward shock which results from the supernova explosion and which is expanding into a uniform interstellar medium. A number of instabilities develop at the supernova…

The theoretical framework of our current understanding of the Universe rests on two main pillars, the Standard Model (SM) of particle physics and Einstein’s theory of General Relativity (GR). This SM+GR framework provides us with an incredible power to explain and predict a plethora of phenomena in observations and…

Project title: Heating and Acceleration through Magnetic Reconnection in Space Plasma TurbulencePI: Daniel Verscharen (MSSL, University College London)DiRAC Resource: Data Intensive at Leicester (DIaL) Jeffersson A. Agudelo Rueda, Daniel Verscharen Advances in space technology have led to the dawn of a new era for multi-spacecraft science missions to explore…

DiRAC resource used: DiAL 2.5 PI: G.S. Collins The relationship between impact crater size and impactor properties, such as size and speed, is key to comparing impactor and crater populations on different planets and dating planetary surfaces. Most of our understanding of this relationship, however, comes from numerical simulations…

The dominant component of matter in the Universe is believed to be dark matter, an unknown subatomic particle that only interacts with ordinary matter via gravity. Through gravitational growth, dark matter forms into so-called halos, within these halos that the visible galaxies we see in the Universe form and…

The architectures of planetary systems discovered by Kepler are poorly understood. There are far more single-transiting planets than expected from the analysis of the number of multi-transiting systems, assuming that all planetary systems are co-planar. However, stars are not born in isolation, and interactions between stars can perturb their…

This project is focused on the study of field theories relevant for building holographic cosmological models. These models use three dimensional QFT to model holographically the laws of physics in the very early universe and make predictions for cosmological observables such as the cosmic microwave background (CMB). Our analysis…

Observations from NASA’s Parker Solar Probe (PSP), launched in 2018, have revealed that close to the Sun the solar wind is tremendously variable, much more so than further out in the Heliosphere. This variability primarily takes the form of local reversals of the usually radial magnetic field known as…