HEP Lattice·hep-lat
4 papers—3 primary·1 cross-listed·reconstructed*
We study approximate decimations in SU(N) LGT that connect the short to long distance regimes, and provide both upper and lower bounds on the exact partition function. This leads to a representation of the exact partition function in terms of successive decimations. The implications for a derivation of confinement from first principles are discussed.
F. Bodin🇫🇷 · Ph. Boucaud🇫🇷 · N. Cabibbo🇮🇹 · F. Di Carlo🇮🇹 · R. De Pietri🇮🇹 · F. Di Renzo🇮🇹 · H. Kaldass🇩🇪 · A. Lonardo🇮🇹 · M. Lukyanov · S. De Luca🇮🇹 · J. Micheli🇫🇷 · V. Morenas🇫🇷 and 10 other authors
We present the APE (Array Processor Experiment) project for the development of dedicated parallel computers for numerical simulations in lattice gauge theories. While APEmille is a production machine in today's physics simulations at various sites in Europe, a new machine, apeNEXT, is currently being developed to provide multi-Tflops computing performance. Like previous APE machines, the new supercomputer is largely custom designed and specifically optimized for simulations of Lattice QCD.
K. Holland🇺🇸 · M. Pepe🇨🇭 · U.-J. Wiese🇨🇭
Pure Yang-Mills theory has a finite-temperature phase transition, separating the confined and deconfined bulk phases. Svetitsky and Yaffe conjectured that if this phase transition is of second order, it belongs to the universality class of transitions for particular scalar field theories in one lower dimension. We examine Yang-Mills theory with the symplectic gauge groups Sp(N). We find new evidence supporting the Svetitsky-Yaffe conjecture and make our own conjecture as to which gauge theories have a universal second order deconfinement phase transition.
B. Kessler🇺🇸 · L. Li🇺🇸 · Y. Meurice🇺🇸
We take advantage of the fact that in lambda phi ^4 problems a large field cutoff phi_max makes perturbative series converge toward values exponentially close to the exact values, to make optimal choices of phi_max. For perturbative series terminated at even order, it is in principle possible to adjust phi_max in order to obtain the exact result. For perturbative series terminated at odd order, the error can only be minimized. It is however possible to introduce a mass shift in order to obtain the exact result. We discuss weak and strong coupling methods to determine the unknown parameters. The numerical calculations in this article have been performed with a simple integral with one variable. We give arguments indicating that the qualitative features observed should extend to quantum mechanics and quantum field theory. We found that optimization at even order is more efficient that at odd order. We compare our methods with the linear delta-expansion (LDE) (combined with the principle of minimal sensitivity) which provides an upper envelope of for the accuracy curves of various Pade and Pade-Borel approximants. Our optimization method performs better than the LDE at strong and intermediate coupling, but not at weak coupling where it appears less robust and subject to further improvements. We also show that it is possible to fix the arbitrary parameter appearing in the LDE using the strong coupling expansion, in order to get accuracies comparable to ours.
* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.