Ms
Monique A. Henson
(Jodrell Bank Centre for Astrophysics, University of Manchester)
9/8/16, 11:15 AM
Dr
Nicolas Garron
(University of Liverpool)
9/8/16, 11:45 AM
High performance computing is now essential in research, even for the most fundamental sciences. In particle physics, the forces that bind the quark together are so strong that non-perturbative methods are required. The only way to define the theory properly is through numerical simulations, called lattice QCD (Quantum Chromo Dynamics is the theory of the strong nuclear interaction). Lattice...
Prof.
Mark Hannam
(Cardiff University)
9/8/16, 12:15 PM
The recent first direct detection of gravitational waves relied on accurate theoretical models of the signals produced by colliding black holes. Current models were tuned to numerical solutions of Einstein's equations for the last orbits and merger of two black holes, and a large number of follow-up numerical-relativity simulations were performed to cross-check the results and test for...
Mr
Justus Tobias Tsang
(University of Southampton)
9/8/16, 12:45 PM
Poster
I will present the status of RBC/UKQCDs charmed meson decay constant study. I will also highlight RBC/UKQCDs wider charm physics program and outline current studies.
Mr
Andrea Cristini
(Keele University)
9/8/16, 12:45 PM
Poster
Stellar models are important for many areas of astrophysics, for example nucleosynthesis yields, supernova progenitor models and understanding physics at extreme conditions. One of the longest standing problems with stellar evolution models is the treatment of convection. To study convection and turbulent motions in stellar interiors, detailed 3D hydrodynamical simulations are...
Prof.
Paul Shellard
(University of Cambridge)
9/8/16, 12:45 PM
Poster
Poster describing the work of the Intel Parallel Computing Centre associated with the COSMOS@DiRAC SMP Facility hosted in Cambridge. This describes the unique hybrid architecture of the COSMOS system, including shared-memory capabilities and accelerators (Xenon Phi) and radical optimisations that have been undertaken for new many-core processors. Highlights include refactoring of the Modal...
Mr
Thomas Helfer
(Kings College London)
9/8/16, 12:45 PM
Poster
While static axis-symmetric solutions of gravitating cosmic strings have been found numerically, dynamical solutions are much harder propositions and little has been done in this aspect. We developed a solver for local U(1) together with Einstein field equations. Using the solutions of strings with perturbations from Vachaspati and Garfinkle, we find initial data for our string and construct...
Mr
Gerardo Ramon Fox
(University of St. Andrews)
9/8/16, 12:45 PM
Poster
F. G. Ramón Fox (1) and Ian Bonnell (1)
(1)University of St. Andrews
Galactic scale gas flows feed the growth of molecular clouds, the regions where stars form in high-density cores. These flows also play a role in driving the internal dynamics of these clouds, which affects their overall stability and star formation activity. The triggering of star formation involves a connection between...
Dr
Mark Richardson
(University of Oxford)
9/8/16, 12:45 PM
Poster
The circumgalactic medium (CGM) encompasses gas that extends from the outskirts of a galaxy to the edge of its halo, mediating gas accretion and outflows. Observations of absorption in background quasar spectra reveal a wealth of information about the structure of the CGM, in particular that it is an environment polluted by metals and cool gas from galactic outflows. By using simulations of...
Dr
Eugene Lim
(King's College London), Mr
Thomas Helfer
(Kings College London)
9/8/16, 12:45 PM
Poster
GRChombo is a new numerical relativity code specifically designed to efficiently and easily simulate the disparate length scales encountered in GR using fully adaptive mesh refinement and the latest parallel computing techniques. Applications range from gravitational wave signals produced from black hole mergers through to critical phenomena for high-dimensional black holes.
Dr
Azusa Yamaguchi
(Software Architect)
9/8/16, 12:45 PM
Poster
In this proceedings we discuss the motivation, implementation details, and performance of a new physics code base called Grid. It is intended to be more performant, more general, but similar in spirit to QDP++[ 6 ]. Our approach is to engineer the basic type system to be consistently fast, rather than bolt on a few optimised routines, and we are attempt to write all our optimised routines...
Dr
Nobuya Nishimura
(Keele University)
9/8/16, 12:45 PM
Poster
A variety of elements has been synthesised in the evolution of stars and supernovae since the Big-Bang. The thermonuclear nuclear reaction is the physical process responsible for the production of elements, and also drives nuclear-burnings in stellar interiors. We need to know accurate reaction rates to help understand the cosmic origin of elements. In our project, we try to identify “key”...
Mr
Sergio Martin-Alvarez
(University of Oxford)
9/8/16, 12:45 PM
Poster
Regardless of being acknowledged as a relevant factor in several astrophysical processes, the study of magnetic fields has been one of the most elusive areas of cosmology and galaxy evolution up to this day. The reason for it are both the complications associated with their observation and measurements, and the intricate difficulty to model them. However, the resources required to tackle them...
Prof.
Paul Shellard
(University of Cambridge)
9/8/16, 12:45 PM
Poster
We apply highly efficient modal methods (developed during the Planck analysis) to large-scale structure distributions in order to optimally evaluate the bispectrum in three dimensions. Currently, deployed on dark matter distributions from N-body codes, this tool is intended for estimating higher-order correlation functions from huge galaxy surveys like Euclid.
Mr
Felix Sainsbury-Martinez
(University of Exeter)
9/8/16, 12:45 PM
Poster
Low-Mass stars are typically fully convective, and as such their dynamics may differ significantly from sun-like stars. Here we present a series of 3D anelastic simulations of fully convective stars, designed to investigate how the meridional circulation, the differential rotation, and entropy are affected by varying stellar parameters, such as the luminosity or the rotation rate. We also...
Prof.
Peter Boyle
(Edinburgh)
9/8/16, 12:45 PM
Poster
We present a new class of multigrid solver algorithm suitable for the solution of 5d chiral fermions such as Domain Wall fermions and the Continued Fraction overlap. Unlike HDCG, arXiv:1402.2585, the algorithm works directly on a nearest neighbour fine operator. The fine operator used is Hermitian indefinite, for example Γ5Ddwf, and convergence is achieved with an indefinite matrix solver such...
Dr
Taysun Kimm
(KICC and IoA, University of Cambridge)
9/8/16, 12:45 PM
Poster
Reionisation in the early universe is likely driven by LyC photons from dwarf galaxies. Using high-resolution, cosmological radiation-hydrodynamic simulations, we study the escape of LyC photons from mini-haloes with the mass Mhalo < 1e8 Msun. Our simulations include a new thermo-turbulent star formation model, non-equilibrium photo-chemistry, and important stellar feedback processes...
Dr
Jonathan Chardin
(Institute of Astronomy (IOA) and Kavli Institute for Cosmology Cambridge (KICC), University of Cambridge)
9/8/16, 12:45 PM
Poster
Lyman-alpha forest data probing the post-reionization Universe shows surprisingly large opacity fluctuations over rather large ( 50 comoving Mpc/h) spatial scales.
We model these fluctuations using a hybrid approach utilizing the large volume Millennium simulation to predict the spatial distribution of QSOs combined with smaller scale full hydrodynamical simulation performed with RAMSES and...
Dr
Tom Goffrey
(University of Exeter)
9/8/16, 12:45 PM
Poster
Stellar evolution is influenced by a wide range of complex, multi-dimensional phenomena. The MUlti-dimensional Stellar Implicit Code, MUSIC, is a new code developed in Exeter with international collaborators that is designed to study such processes. MUSIC is a fully compressible, time-implicit code, which utilises realistic opacity and equation of state data, and is capable of simulating a...
Dr
Oliver Witzel
(University of Edinburgh)
9/8/16, 12:45 PM
Poster
In the Standard Model of elementary particle physics, b-quarks are the heaviest quarks forming hadronic bound states. Their large mass allows for many decay modes and by that tests of the Standard Model. Using numerical lattice QCD simulations we calculate decays of B-mesons, quark-antiquark pairs with one constituent a b-quark, into one other hadron and leptons. These calculations lead to...
Mr
Benjamin Lewis
(University of Exeter)
9/8/16, 12:45 PM
Poster
We expand on Lewis, et al. (2015) and (2016, submitted), which considered only ideal MHD simulations of the collapse of molecular cloud cores without turbulence, and use radiation magnetohydrodynamical calculations to explore how the physics of turbulence, rotation, magnetism and radiation influences the formation of protostars.
The inclusion of a flux limited diffusion radiative transfer...
Mr
James Willis
(ICC, Durham University)
9/8/16, 12:45 PM
Poster
SWIFT - Smoothed-Particle Hydrodynamics With Interdependent Fine-grained Tasking. We will describe the methods and techniques used to vectorise SWIFT and present the improvement to performance due to vectorisation.
Ms
Laura Keating
(Institute of Astronomy, University of Cambridge)
9/8/16, 12:45 PM
Poster
Observations of absorption lines in the spectra of QSOs out to redshift 7 provide an important probe of the intergalactic medium (IGM) at the tail end of reionization. In this talk I will discuss my work using high-resolution cosmological simulations to model the enrichment and ionization state of the high-redshift IGM. I will present results from cosmological simulations run with different...
Ms
Monique A. Henson
(Jodrell Bank Centre for Astrophysics, University of Manchester)
9/8/16, 12:45 PM
Poster
As the largest gravitationally bound structures in the Universe, galaxy clusters offer a crucial opportunity to study both the physics of structure formation and cosmology. There has been a wealth of work characterising the structure and properties of galaxy clusters in numerical simulations, however these have been focussed on dark matter only simulations or have been restricted to small...
Dr
Roger Horsley
(University of Edinburgh)
9/8/16, 12:45 PM
Poster
The proton consists of two valence up quarks, one
down quark together with a `sea' of quark anti-quark pairs
and gluons. How each constituent contributes to the
total spin of the proton has remained a mystery for many
years. In particular the quark contribution is much
smaller than expected. We discuss here our lattice QCD
determination of the quark contribution, using...
Dr
Rowan Smith
(University of Manchester)
9/8/16, 12:45 PM
Poster
We show how the AREPO code can be used to follow the ISM in spiral type galaxy simulations at unprecedented scales. The resolution extends from 6 kpc down to sub-pc scales and includes important physical processes such as supernova feedback, time-dependent chemistry and self-shielding, and gas self gravity. Such resolution means that we can resolve sub-structure within individual molecular...
Prof.
Christine Davies
(University of Glasgow)
9/8/16, 2:00 PM
Science parallel talk
We report on the HPQCD calculation of the u/d HVP contribution to a_mu, discussed in arXiv:1601.03071. This allows us to obtain a total HVP contribution from u, d, s and c quarks and including an estimate of disconnected pieces and QED and isospin effects of 666(6)(12) x 10^{-10}.
Our result implies a discrepancy between the experimental determination of a_mu and the Standard Model of 3...
Dr
Guido Cossu
(Edinburgh University)
9/8/16, 2:30 PM
We discuss the development of a new data parallel library targeted to any problem requiring solving partial differential equations on a regular grid. The main motivation in the development is the proliferation of the hierarchies of parallelism in modern architectures that requires constant adaptations of large parts of the codebases for each new architecture like the new Intel Knights Landing....
Dr
Eugene Lim
(King's College London)
9/8/16, 2:30 PM
Science parallel talk
We investigate the robustness of inflation to inhomogenous initial conditions using the numerical relativity package GRCHOMBO. We show that small field inflation is generally less robust than large field inflation. Furthermore, we show that while increasing inhomogeneities can lead to the formation of black holes during inflation, the black holes will not achieve the Nariai mass and hence will...
Mr
Matthew Smith
(Institute of Astronomy, Cambridge)
9/8/16, 2:50 PM
Science parallel talk
The accurate modelling of stellar feedback from massive stars to the interstellar medium (ISM) is of crucial importance for understanding galaxy formation. Failure to include these processes in hydrodynamic simulations leads to the catastrophic overproduction of stars relative to observations. Supernovae (SNe) and winds from massive stars are a major source of stellar feedback but correctly...
Dr
Richard Rollins
(DiRAC / University of Manchester)
9/8/16, 2:50 PM
In preparation for the procurement of their next generation of supercomputers, DiRAC have developed a suite of benchmarks based on the software in use on their current systems. Working with vendors, this will allow us to characterise the performance of key particle physics and astrophysics algorithms on newly available hardware. This talk will provide an overview of the design and development...
Mr
Sergio Martin-Alvarez
(University of Oxford)
9/8/16, 3:10 PM
Science parallel talk
Regardless of being acknowledged as a relevant factor in several astrophysical processes, the study of magnetic fields has been one of the most elusive areas of cosmology and galaxy evolution up to this day. The reason for it are both the complications associated with their observation and measurements, and the intricate difficulty to model them. However, the resources required to tackle them...
Mr
James Willis
(ICC, Durham University)
9/8/16, 3:10 PM
The next-generation cosmological code SWIFT has been demonstrated to outperform current codes by more than an order of magnitude on ordinary x86-based clusters such as the cosma system in DiRAC. This has been achieved thank to the use of better algorithm, task-based parallelism and asynchronous communications. However, the next generation of machines that will contain many more cores per node,...
Ms
Ricarda Beckmann
(University of Oxford)
9/8/16, 4:00 PM
Science parallel talk
The growth of supermassive black holes (SMBHs) powering quasars at redshift z=6 and above is still poorly understood. Efforts so far have either concentrated on black hole (BH) seed formation mechanisms, or approximated the SMBHs using massive seeds in low resolution simulations. The work presented here will bridge the gap, following the growth of a SMBH from its origins as a stellar mass seed...
Dr
Richard Booth
(Institute of Astronomy, Cambridge, UK)
9/8/16, 4:20 PM
Science parallel talk
Planet formation occurs in accretion discs that surround young stars. Using DiRAC we have been able to characterize the dynamics of these discs throughout the various stages of their evolution from massive, self-gravity dominated discs through to their eventual dispersal through photo-evaporation. I will present new insights that have arisen out of these simulations on topics including...
Dr
James Wurster
(University of Exeter)
9/8/16, 4:40 PM
Science parallel talk
Numerical simulations are required to model the complicated physical processes that occur during the formation of a star. As we learn more about the star formation process, we begin to include even more complex processes, which can become numerically expensive. Thus, not only is the new physics required, but so are novel algorithms and HPC facilities.
I will discuss our research on star...
