The Structure of the Universe: Cosmology, Exoplanets and Lattice QCD

点击翻译按钮获取中文摘要

This proposal aims to address key questions about the fundamental structure of the Universe and the origin and nature of the galaxies, stars and planets within it. This proposal is to enhance the STFC DiRAC Facility which provides the primary computational platform for UK particle physicists, cosmologists and astrophysicists. The proposal will fund two high performance computing systems: First, there is a flexible shared-memory (SMP) node with 16TB, which will be the largest such system in Europe. Secondly, there is a powerful tightly-coupled cluster capable of 200Tflops (HPCS). This proposal will advance our understanding in 4 key scientific areas:A. Science exploitation of the CMB and Large-scale Structure surveys: The cosmic microwave background (CMB) remains the premier source for cosmological information. Planck satellite data dramatically supersedes the previous WMAP data and we will use it to constrain fundamental cosmology. With Planck data releases scheduled for 2013 and 2014, this upgrade will leverage the proprietary data, maximizing science exploitation by COSMOS members. Work on large-scale structure encompasses using surveys to constrain the properties of the Universe and understanding the hierarchical formation of galaxies. B. Observational consequences of the Early Universe. The consortium has pioneered the use of lattice simulations to understand the physics of non-linear phenomena in the early universe. This is expected in most cosmological models, including those with phase transitions, cosmic defects and extra dimensions. The challenge using the new SMP node will be to calculate the observable consequences of these theories, which can range from signatures in the CMB or large-scale structure through to the production of dark matter or primordial gravitational waves.C. Extra-solar planets and their atmospheres.The SMP node will also support key UK research in extra-solar planets. This is concerned with the observation and characterisation of exoplanets and their atmospheres, developing key numerical codes which are vital to this international endeavour. The new SMP system will allow much more information to be extracted from spectroscopic data from exoplanet environments. This will help us answer some of the oldest questions in science such as: Are there worlds beyond our solar system? Are they numerous or rare? How many of them have the right conditions for life?D. Quantum chromodyanamics (QCD)We shall use the HPCS to carry out the research programme of the UKQCD Consortium: numerical solution of QCD and related theories using techniques known collectively as lattice field theory.QCD describes how quarks bind into observable particles known as hadrons. By solving QCD on supercomputers, we gain information about the rich physics which results from the strong interactions between quarks. Furthermore, precise QCD calculations are necessary to connect experimental measurements to fundamental parameters governing how quarks change their type, or "flavour."So far, the Standard Model (SM) of particle physics (which unites the electromagnetic, weak, and strong forces) appears to be sufficient to describe quark flavour-changing interactions. However many physicists expect there to be physics "beyond" the Standard Nodel (BSM); precise measurements combined with accurate QCD computations may reveal hints of this new physics.In several cases, lattice QCD is the only known method for achieving the few-percent precision necessary to distinguish between Standard and non-Standard physics.Lattice field theory also offers accurate methods for exploring field theories with strongly interacting particles. UKQCD groups are active in categorizing possible BSM theories. In addition, UKQCD are studying these types of theories under extreme conditions such as high temperature and/or high particle density. These calculations complement experimental programs at RHIC and LHC.