A5089304007- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Advanced Data Storage Technologies
- Parallel Computing and Optimization Techniques
- High-Energy Particle Collisions Research
- Distributed and Parallel Computing Systems
- Distributed systems and fault tolerance
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- Radio Astronomy Observations and Technology
- Real-Time Systems Scheduling
- Physics of Superconductivity and Magnetism
- Nuclear physics research studies
- Network Time Synchronization Technologies
- Dark Matter and Cosmic Phenomena
- Plasma Diagnostics and Applications
- Computational Physics and Python Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Satellite Image Processing and Photogrammetry
- Maritime and Coastal Archaeology
- Radiation Effects in Electronics
- Geological Formations and Processes Exploration
- Spectral Theory in Mathematical Physics
- Remote Sensing in Agriculture
Los Alamos National Laboratory
2010-2022
Sandia National Laboratories California
2014
University of Edinburgh
1986-1990
General Electric (United States)
1962
As noted in Wikipedia, skin the game refers to having ‘incurred risk by being involved achieving a goal’, where ‘ is synecdoche for person involved, and metaphor actions on field of play under discussion’. For exascale applications development US Department Energy Exascale Computing Project, nothing could be more apt, with delivering comprehensive science-based computational that effectively exploit high-performance computing technologies provide breakthrough modelling simulation data...
Supercomputing is evolving toward hybrid and accelerator-based architectures with millions of cores. The Hardware/Hybrid Accelerated Cosmology Code (HACC) framework exploits this diverse landscape at the largest scales problem size, obtaining high scalability sustained performance. Developed to satisfy science requirements cosmological surveys, HACC melds particle grid methods using a novel algorithmic structure that flexibly maps across architectures, including CPU/GPU, multi/many-core,...
Remarkable observational advances have established a compelling cross-validated model of the Universe. Yet, two key pillars this -- dark matter and energy remain mysterious. Next-generation sky surveys will map billions galaxies to explore physics 'Dark Universe'. Science requirements for these demand simulations at extreme scales; be delivered by HACC (Hybrid/Hardware Accelerated Cosmology Code) framework. HACC's novel algorithmic structure allows tuning across diverse architectures,...
We present a calculation of the pion decay constant and second moment quark distribution amplitude within full lattice QCD. Measurements are made on ${12}^{3}$\ifmmode\times\else\texttimes\fi{}24 ${16}^{3}$\ifmmode\times\else\texttimes\fi{}32 lattices, using two flavors Wilson fermion. Different methods used to extract ${f}_{\ensuremath{\pi}}$ give consistent results. find better signal for than in previous calculations obtain results that significantly smaller those obtained from sum-rule...
Summary form only given. We discuss the unique architectural elements of Los Alamos message passing interface (LA-MPI), a high-performance, network-fault-tolerant, thread-safe MPI library. LA-MPI is designed for use on terascale clusters which are inherently unreliable due to their sheer number system components and trade-offs between cost performance. examine in detail design concepts used implement LA-MPI. These include reliability features, such as application-level checksumming,...
We present a set of ultra-large particle-mesh simulations the LyA forest targeted at understanding imprint baryon acoustic oscillations (BAO) in inter-galactic medium. use 9 dark matter only which can, for first time, simultaneously resolve Jeans scale intergalactic gas while covering large volumes required to adequately sample feature. Mock absorption spectra are generated using fluctuating Gunn-Peterson approximation have approximately correct flux probability density functions (PDFs) and...
The target of the Roadrunner Universe project at Los Alamos National Laboratory is a set very large cosmological N-body simulation runs on hybrid supercomputer Roadrunner, world's first petaflop platform. Roadrunner's architecture presents opportunities and difficulties characteristic next-generation supercomputing. We describe new code designed to optimize performance scalability by explicitly matching underlying algorithms machine architecture, using physics problem as an essential aid in...
Remarkable observational advances have established a compelling cross-validated model of the Universe. Yet, two key pillars this -- dark matter and energy remain mysterious. Next-generation sky surveys will map billions galaxies to explore physics 'Dark Universe'. Science requirements for these demand simulations at extreme scales; be delivered by HACC (Hybrid/Hardware Accelerated Cosmology Code) framework. HACC's novel algorithmic structure allows tuning across diverse architectures,...
The Los Alamos Message Passing Interface (LA-MPI) is an end-to-end network-failure-tolerant message-passing system designed for terascale clusters. LA-MPI a standard-compliant implementation of MPI to tolerate network-related failures including I/O bus errors, network card and wire-transmission errors. This paper details the distinguishing features LA-MPI, support concurrent use multiple types interface, reliable message transmission utilizing paths routes between given source destination....
We investigate the use of two types nonlocal ("smeared") sources for quark propagators in quenched lattice QCD at $\ensuremath{\beta}=6.0$ using Wilson fermions $\ensuremath{\kappa}=0.154 \mathrm{and} 0.155$. present results hadron mass spectrum, meson decay constants, masses, chiral condensate, and distribution amplitude pion. The smeared leads to a considerable improvement over previous results. find disturbing discrepancy between baryon spectra obtained Wuppertal wall sources. good...
The advent of powerful cosmological surveys demands a new generation high-precision, large-volume, and high dynamic range simulations structure formation in the Universe. Key aims these are understanding why expansion Universe is accelerating what dark matter made of. availability Roadrunner, world's first petaflop platform, led us to develop hybrid cosmology simulation code making essential use hardware acceleration. We describe strategies underlying aspects its implementation.
We present an investigation of various gauge-invariant definitions the $q\overline{q}$ Bethe-Salpeter (BS) amplitude for mesons in lattice QCD, and compare them to Coulomb Landau gauge BS amplitudes. show that is considerably broadened by use "fat" links (constructed smearing original lattice). A qualitative demonstration Lorentz contraction pion wave function at nonzero momentum given. also calculate density-density correlations discuss limitations extracting charge radius from these...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation David J. Ben Daniel, Stephen Tamor; Theory of Nonthermal Ionization in Cesium Discharges. Phys. Fluids 1 April 1962; 5 (4): 500–501. https://doi.org/10.1063/1.1706647 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Dropdown Menu...
We calculate the kaon $B$-parameter in quenched lattice QCD at $\beta=6.0$ using Wilson fermions $\kappa=0.154$ and $0.155$. use two kinds of non-local (``smeared'') sources for quark propagators to matrix elements between states definite momentum. The smeared yields results with much smaller errors than obtained previous calculations fermions. By combining $\vec p =(0,0,0)$ =(0,0,1)$, we show that one can carry out non-perturbative subtraction necessary remove dominant artifacts induced by...