High-performance simulations of higher representations of Wilson fermions

We present HiRep v2, an open-source software suite for high-performance lattice field theory simulations with dynamical Wilson fermions in higher representations of SU ( N g ) gauge groups. This new version fully supports graphics processing unit (GPU) acceleration, optimizing both gauge configuration generation and measurements for NVIDIA and AMD GPUs. HiRep v2 integrates improved gauge and fermionic lattice actions, advanced inverters, and Monte Carlo algorithms, including the (Rational) Hybrid Monte Carlo ((R)HMC) with Hasenbusch acceleration. It exhibits excellent scalability across multiple GPUs and nodes with minimal efficiency loss, making it a robust tool for large-scale simulations in physics beyond the Standard Model. Program Title: HiRep CPC Library link to program files: (to be added by Technical Editor) Developer’s repository link: https://github.com/claudiopica/hirep Licensing provisions(please choose one): GPLv2 Programming language: C, CUDA C, C++ Supplementary material: Journal reference of previous version: * Does the new version supersede the previous version?: * Reasons for the new version:* Summary of revisions: * Nature of problem(approx. 50-250 words): Lattice Field Theory has proven indispensable for the quantitative understanding of strongly coupled quantum field theories, specifically in providing non-perturbative input to phenomenological models describing the dynamics of Quantum Chromodynamics (QCD) for precision tests of the Standard Model. Simulation software libraries for lattice calculations in QCD are readily available and optimized to run on heterogeneous CPU-GPU architectures with good scaling properties on modern supercomputers. In direct searches for physics beyond the Standard Model, software is needed that can simulate gauge groups other than SU (3) and allow for fermions in higher representations, catering, among other things, to classes of composite Higgs and technicolor theories [1], and predictions in the large- N g limit [2]. There exists no other open-source library that implements the option for higher representations of Wilson fermions with general numbers of colors, that has as many capabilities in terms of actions and measurement code as HiRep . Solution method(approx. 50-250 words): A central element of HiRep is the implementation of a Dirac operator and optimized linear algebra routines that generalize to higher representations and general gauge groups. Since the application of the Dirac operator is one of the main bottlenecks of the numerical simulation, optimizations of the Dirac operator are a central part of any high-performance software implementations. In this work, we present a series of significant developments and enhancements to the HiRep suite. These include but are not limited to, the porting of the code to GPUs, see also [3, 4] for previous progress reports, improvements in computational efficiency, and the introduction of new features to further support advanced lattice simulations. In particular, we show that independent of the theory chosen, our implementation of the Dirac operator reaches excellent performance on GPUs and that the software scales well on state-of-the-art supercomputers to a large number of compute nodes, and HiRep is suitable for simulations of light fermionic masses on large lattices. Another recent performance improvement was achieved in [5], optimizing OpenMP support. Additional comments including restrictions and unusual features (approx. 50-250 words): None. * Items marked with an asterisk are only required for new versions of programs previously published in the CPC Program Library.