174 research outputs found
Implementation of the conjugate gradient algorithm on FPGA devices
Results of porting parts of the Lattice Quantum Chromodynamics code to modern
FPGA devices are presented. A single-node, double precision implementation of
the Conjugate Gradient algorithm is used to invert numerically the Dirac-Wilson
operator on a 4-dimensional grid on a Xilinx Zynq evaluation board. The code is
divided into two software/hardware parts in such a way that the entire
multiplication by the Dirac operator is performed in programmable logic, and
the rest of the algorithm runs on the ARM cores. Optimized data blocks are used
to efficiently use data movement infrastructure allowing to reach intervals of
1 clock cycle. We show that the FPGA implementation can offer a comparable
performance compared to that obtained using Intel Xeon Phi KNL.Comment: Proceedings of the 36th Annual International Symposium on Lattice
Field Theory - LATTICE201
Towards Lattice Quantum Chromodynamics on FPGA devices
In this paper we describe a single-node, double precision Field Programmable
Gate Array (FPGA) implementation of the Conjugate Gradient algorithm in the
context of Lattice Quantum Chromodynamics. As a benchmark of our proposal we
invert numerically the Dirac-Wilson operator on a 4-dimensional grid on three
Xilinx hardware solutions: Zynq Ultrascale+ evaluation board, the Alveo U250
accelerator and the largest device available on the market, the VU13P device.
In our implementation we separate software/hardware parts in such a way that
the entire multiplication by the Dirac operator is performed in hardware, and
the rest of the algorithm runs on the host. We find out that the FPGA
implementation can offer a performance comparable with that obtained using
current CPU or Intel's many core Xeon Phi accelerators. A possible multiple
node FPGA-based system is discussed and we argue that power-efficient High
Performance Computing (HPC) systems can be implemented using FPGA devices only.Comment: 17 pages, 4 figure
Solutions of D=2 supersymmetric Yang-Mills quantum mechanics with SU(N) gauge group
We describe the generalization of the recently derived solutions of D=2
supersymmetric Yang-Mills quantum mechanics with SU(3) gauge group to the
generic case of SU(N) gauge group. We discuss the spectra and eigensolutions in
bosonic as well as fermionic sectors.Comment: 21 pages, no figure
The CLS 2+1 flavor simulations
We report on the status of large volume simulations with 2+1 dynamical
fermions which are being performed by the CLS initiative. The algorithmic
details include: open boundary conditions, twisted mass reweighting and RHMC,
whereas the main feature of the simulation strategy is the approach to the
physical point along a trajectory of constant trace of the mass matrix. We
comment on the practical side of the above issues using as examples some of the
newly generated ensembles, which presently cover lattice spacings between 0.05
fm and 0.11 fm and pion masses between 150 MeV and 415 MeV.Comment: 8 pages, 6 figures, talk presented at the 32nd International
Symposium on Lattice Field Theory, 23-28 June, 2014, Columbia University New
York, NY. appears in PoS(LATTICE2014)02
Gauge invariant plane-wave solutions in supersymmetric Yang-Mills quantum mechanics
We derive the spectra of D=2, SU(3) supersymmetric Yang-Mills quantum
mechanics in all fermionic sectors. Moreover, we provide exact expressions for
the corresponding eigenvectors in the sectors with none and one fermionic
quantum. We also generalize our results obtained in a cut Fock space to the
infinite cut-off limit.Comment: 38 pages, 1 figur
Detailed study of a transition point in the Veneziano-Wosiek model of Planar Quantum Mechanics
Following a model recently investigated by Veneziano and Wosiek we briefly
introduce Planar Quantum Mechanics (PQM). Then, we present high precision
numerical results in the sectors with two and three fermions. We confirm, that
the transition point in the 't Hooft's coupling constant lambda in these
sectors occurs at lambda = 1, as was expected.Comment: 10 pages, 8 figures, submitted to Acta Physica Polonic
Exact solutions to D=2 Supersymmetric Yang-Mills Quantum Mechanics with SU(3) gauge group
In this article we present the cut Fock space approach to the D=d+1=2,
Supersymmetric Yang-Mills Quantum Mechanics (SYMQM). We start by briefly
introducing the main features of the framework. We concentrate on those
properties of the method which make it a convenient set up not only for
numerical calculations but also for analytic computations. In the main part of
the article a sample of results are discussed, namely, analytic and numerical
analysis of the D=2, SYMQM systems with SU(2) and SU(3) gauge symmetry.Comment: Proceedings of the XLIX Cracow School of Theoretical Physics, 200
Eigenvalues and eigenvectors of the Laplace operator in d-dimensional cut Fock basis
We present exact expressions for the eigenvalues and eigenvectors of the
d-dimensional Laplace operator in a cut Fock basis.Comment: 13 pages, 2 figure
On one-loop corrections to matching conditions of Lattice HQET including 1/m_b terms
HQET is an effective theory for QCD with N_f light quarks and a massive
valence quark if the mass of the latter is much bigger than Lambda_QCD. As any
effective theory, HQET is predictive only when a set of parameters has been
determined through a process called matching. The non-perturbative matching
procedure including 1/m_b terms, developped by the ALPHA collaboration,
consists of 19 carefully chosen observables which are precisely computable in
lattice QCD as well as in lattice HQET. The matching conditions are then a set
of 19 equations which relate the QCD and HQET values of these observables. We
present a study of one-loop corrections to two generic matching observables
involving correlation function with an insertion of the A_0 operator. Our
results enable us to quantify the quality of the relevant observables in view
of the envisaged non-perturbative implementation of this matching procedure.Comment: 7 pages, 4 figures; presented at th 31st International Symposium on
Lattice Field Theory (LATTICE2013), 29 July - 3 August 2013, Mainz, German
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