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InTheLoop | 02.17.2015

February 17, 2015

Across the Universe: Cosmology Data Management Workshop Draws Stellar Crowd

ESnet and Internet2 hosted last week’s CrossConnects Workshop on “Improving Data Mobility & Management for International Cosmology,” a two-day meeting ESnet Director Greg Bell described as the best one yet in the series. More than 50 members of the cosmology and networking research community turned out for the event hosted at Lawrence Berkeley National Laboratory, while another 75 caught the live stream from the workshop.

The Feb. 10-11 workshop provided a forum for discussing the growing data challenges associated with the ever-larger cosmological and observational data sets, which are already reaching the petabyte scale. »Read more.

Local High School Students Tour NERSC

Last week, two groups of students from East Bay high schools descended on the Oakland Scientific Facility to learn more about supercomputing and networking.

On Wednesday, Feb. 11, 30 students from a computer science class at Doherty Valley High School in San Ramon visited. Richard Gerber, head of NERSC’s User Services Group, gave the students an introduction to the center and scientific computing, followed by a tour of the machine room.

On Thursday, Feb. 12, 31 students from the Computer Academy at Oakland Technical High School rode the bus down Broadway for a tour of the machine room and a Q&A session on computing-related careers. David Skinner and Jon Bashor gave the students of an overview of NERSC and the kinds of problems tackled by users. After a machine room tour, the students spent 45 minutes in a career-focused Q&A session with Skinner, Annette Greiner and John Shalf. The visit was part of the school’s Career Pathways program aimed at bridging what students learn in the classroom with career options at local institutions. »See photos.

DOE Scientists Team up to Demonstrate Scientific Potential of Big Data Infrastructure

Over the past six months, groups of researchers supported by the Department of Energy (DOE) have taken on the challenge to demonstrate new approaches for collecting, moving, sharing and analyzing massive scientific data sets in areas ranging understanding the makeup of our universe to designing new materials at the molecular scale.

Researchers at Lawrence Berkeley National Laboratory (Berkeley Lab) led four of the 11 Science Data Pilot Projects and provided support to five others. The multi-discipline teams tapped into some of the world’s leading facilities for research, including light sources, supercomputers and particle accelerators at DOE national labs, as well as DOE’s ultra-fast network, ESnet. Berkeley Lab facilities used by the projects include the National Energy Research Scientific Computing Center (NERSC), the Advanced Light Source (ALS) and ESnet, which is managed by Berkeley Lab.

The goal was to demonstrate what could be achieved when such facilities are specifically linked to carry out specialized research projects. The idea was to demonstrate the potential of such a focused science data infrastructure, which took up to several months to aggregate, as well as the steps needed to make such heroic efforts possible as everyday events. »Read more.

This Week's CS Seminars

»CS Seminars Calendar

Applied Mathematics:Topologically protected edge states in continuous two-dimensional honeycomb structures

Thursday, Feb. 19, 4:10 p.m.–5 p.m., 60 Evans Hall, UC Berkeley
Michael Weinstein, Columbia University

An edge state is a time-harmonic mode of a conservative wave system, e.g. Schroedinger, Maxwell, which is propagating (plane-wave-like) parallel to and localized, transverse to a line-defect or “edge”. Topologically protected edge states are edge states which are immune to local scattering impurities.

First studied in the context of the quantum Hall effect, protected edge states have attracted great interest recently due to their role in the field of topological insulators. Such states are potential vehicles for robust energy-transfer in the presence of strong localized defects and random imperfections. They are therefore considered ideal for use in nano-scale devices.

The theoretical understanding of topological protection has mainly come from discrete (tight-binding) models and direct numerical simulation. After an introduction to the spectral properties of continuous honeycomb structures and their novel properties such as Dirac points, we introduce a rich family of continuum PDE models and discuss regimes (“phases") where topologically protected edge states exist along a “zig-zag edge", and regimes where edge states may exist but are not protected. These results follow from a general theorem on the bifurcation of edge states from Dirac points of the background honeycomb structure. This bifurcation is seeded by the zero mode of an effective Dirac equation. The key to applying the general theorem is the verification of a spectral no-fold condition along the zig-zag edge.

This is joint work with C.L. Fefferman and J.P. Lee-Thorp.