Lattice Field Theory at the Exascale Frontier

Lead Research Organisation: University of Plymouth
Department Name: Sch of Eng, Comp and Math (SECaM)

Abstract

Lattice Field Theory (LFT) provides the tools to study the fundamental forces of nature using numerical simulations. The traditional realm of application of LFT has been Quantum Chromodynamics (QCD), the theory describing the strong nuclear force within the Standard Model (SM) of particle physics. These calculations now include electromagnetic effects and achieve sub percent accuracy. Other applications span a wide range of topics, from theories beyond the Standard Model, to low-dimensional strongly coupled fermionic models, to new cosmological paradigms. At the core of this scientific endeavour lies the ability to perform sophisticated and demanding numerical simulations. The Exascale era of High Performance Computing therefore looks like a time of great opportunities.

The UK LFT community has been at the forefront of the field for more than three decades and has developed a broad portfolio of research areas, with synergetic connections to High-Performance Computing, leading to significant progress in algorithms and code performance.
Highlights of successes include: influencing the design of new hardware (Blue Gene systems); developing algorithms (Hybrid Monte Carlo) that are used widely by many other communities; maximising the benefits from new technologies (lattice QCD practitioners were amongst the first users of new platforms, including GPUs for scientific computing); applying LFT techniques to new problems in Artificial Intelligence.

The research programme in LFT, and its impact, can be expanded in a transformative way with the advent of pre-Exascale and Exascale systems, but only if key challenges are addressed. As the number of floating point operations per second increases, the communications between computing nodes are lagging behind, and this imbalance will severely affect future LFT simulations across the board.

These challenges are common to all LFT codebases, and more generally to other communities that are large users of HPC resources. The bottlenecks on new architectures need to be carefully identified, and software that minimises the communications must be designed in order to make the best usage of forthcoming large computers. As we are entering an era of heterogeneous architectures, the design of new software must clearly isolate the algorithmic progress from the details of the implementation on disparate hardware, so that our software can be deployed efficiently on forthcoming machines with limited effort.

The goal of the EXA-LAT project is to develop a common set of best practices, KPIs and figures of merit that can be used by the whole LFT community in the near future and will inform the design and procurement of future systems. Besides the participation of the LFT community, numerous vendors and computing centres have joined the project, together with scholars from 'neighbouring' disciplines. Thereby we aim to create a national and international focal point that will foster the activity of scholars, industrial partners and Research Sotfware Engineers (RSEs). This synergetic environment will host training events for academics, RSEs and students, which will contribute to the creation of a skilled work force immersed in a network that comprises the leading vendors in the subject.

EXA-LAT will set the foundations for a long-term effort by the LFT community to fully benefit of Exascale facilities and transfer some of the skills that characterise our scientific work to a wider group of users across disciplines.

Publications

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Description EXALAT is the EPSRC-funded research project on Lattice Field Theory at the Exascale Frontier.

Lattice Field Theory (LFT) provides the tools to study the elementary particle dynamics of quantum systems in strongly coupled regimes that are not accessible to the usual perturbative expansions. Applications span a wide range of topics:

Quantum Chromodynamics (QCD), the theory describing the strong nuclear force within the Standard Model (SM) of particle physics.
Theories beyond the Standard Model
Low-dimensional strongly coupled fermionic models
Study of new cosmological paradigms.
Exploitation Route The advent of pre-Exascale and Exascale systems will allow us to expand the science programme in LFT, increasing the scientific impact of the UK programme.
EXALAT will develop a roadmap for a broad community to exploit exascale facilities by the mid-2020s provide benchmarks and identify bottlenecks develop novel algorithms to attack signal-to-noise issues, multigrid inverters, instabilities in current algorithms and new directions based on artificial intelligence.
Sectors Digital/Communication/Information Technologies (including Software),Education,Other

URL https://www.exalat.org
 
Description EXALAT is informing the benchmarking and testing phase of the acquisition of new pre-exascale machines for the EPSRC Excalibur initiative. The group is engaging with the main stakeholders and vendors of the market, defining the metrics of performances to asses the value of the hardware and of the software that will use it.
First Year Of Impact 2021
Sector Digital/Communication/Information Technologies (including Software)
Impact Types Economic

 
Description EXALAT algorithm workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact This workshop has been a starting point for setting the objectives of the EXALAT working group on algorithms and the timeline for their implementation.
The main result of the workshop was the creation of a working group of experts who is willing to engage with many different algorithmic aspects of the exascale rampup.
The aim of the work-group is to support a community effort to identify innovative algorithms and methodologies that are best suited to exploit the parallelism necessary to reach efficient Exascale computing usage.
The working group will investigate novel algorithms developed in complementary research fields (data science, big data) that can have a positive impact in our research field and help achieve the Exascale computing capabilities while offering the clear potential for creating links to industry and interdisciplinarity.
The working group will identify the possibility of a joint coding effort to extend some of the most widely spread community simulation platforms towards better compliance with the Exascale candidate hardware.
The working group will identify whether it is feasible to implement a complete set of libraries and packages to be exploited by the whole research community, to use as building blocks and standard definitions for a variety of use cases.
Year(s) Of Engagement Activity 2020
URL https://www.exalat.org/2020/08/14/exalat-algorithm-meeting/