Limits...
Propagators and topology.

Maas A - Eur Phys J C Part Fields (2015)

Bottom Line: The results show that the salient low-momentum features of the propagators are qualitatively retained under smearing at sufficiently small momenta, in agreement with an equivalence of both perspectives.However, the mid-momentum behavior is significantly affected.These results are also relevant for the construction of truncations in functional methods, as they provide hints on necessary properties to be retained in truncations.

View Article: PubMed Central - PubMed

Affiliation: Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria.

ABSTRACT

Two popular perspectives on the non-perturbative domain of Yang-Mills theories are either in terms of the gluons themselves or in terms of collective gluonic excitations, i.e. topological excitations. If both views are correct, then they are only two different representations of the same underlying physics. One possibility to investigate this connection is by the determination of gluon correlation functions in topological background fields, as created by the smearing of lattice configurations. This is performed here for the minimal Landau gauge gluon propagator, ghost propagator, and running coupling, both in momentum and position space for SU(2) Yang-Mills theory. The results show that the salient low-momentum features of the propagators are qualitatively retained under smearing at sufficiently small momenta, in agreement with an equivalence of both perspectives. However, the mid-momentum behavior is significantly affected. These results are also relevant for the construction of truncations in functional methods, as they provide hints on necessary properties to be retained in truncations.

No MeSH data available.


The gluon dressing function in position space for various numbers of smearing sweeps. The top panel is for a discretization of  fm, the middle panel for  fm, and the bottom panel for  fm. All results from  lattices
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Fig13: The gluon dressing function in position space for various numbers of smearing sweeps. The top panel is for a discretization of  fm, the middle panel for  fm, and the bottom panel for  fm. All results from lattices

Mentions: The result for different smearing levels are shown for the three discretizations in Fig. 13. Some qualitative difference is observed for the different discretizations. This is mainly that the finer the discretization, the earlier a behavior is seen which appears on coarser lattice only for a stronger suppression. This effect is of the same size as the difference due to the different volumes of the not smeared case, and hence is probably rather a finite-volume artifact. It is therefore possible to concentrate on the results for the largest physical volumes, and therefore longest accessible times. It is found that the decay becomes slower the more smearing has been performed. This moves the characteristic zero crossing [1] to larger times, but it is even after substantial smearing still observable. Even in the cases where the zero crossing is not visible, and even after the longest amount of smearing, the correlator still curves incorrectly for a physical correlator. Thus, the generic properties of the gluon propagator remain even in a pure self-dual/topological background.Fig. 13


Propagators and topology.

Maas A - Eur Phys J C Part Fields (2015)

The gluon dressing function in position space for various numbers of smearing sweeps. The top panel is for a discretization of  fm, the middle panel for  fm, and the bottom panel for  fm. All results from  lattices
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4376381&req=5

Fig13: The gluon dressing function in position space for various numbers of smearing sweeps. The top panel is for a discretization of  fm, the middle panel for  fm, and the bottom panel for  fm. All results from lattices
Mentions: The result for different smearing levels are shown for the three discretizations in Fig. 13. Some qualitative difference is observed for the different discretizations. This is mainly that the finer the discretization, the earlier a behavior is seen which appears on coarser lattice only for a stronger suppression. This effect is of the same size as the difference due to the different volumes of the not smeared case, and hence is probably rather a finite-volume artifact. It is therefore possible to concentrate on the results for the largest physical volumes, and therefore longest accessible times. It is found that the decay becomes slower the more smearing has been performed. This moves the characteristic zero crossing [1] to larger times, but it is even after substantial smearing still observable. Even in the cases where the zero crossing is not visible, and even after the longest amount of smearing, the correlator still curves incorrectly for a physical correlator. Thus, the generic properties of the gluon propagator remain even in a pure self-dual/topological background.Fig. 13

Bottom Line: The results show that the salient low-momentum features of the propagators are qualitatively retained under smearing at sufficiently small momenta, in agreement with an equivalence of both perspectives.However, the mid-momentum behavior is significantly affected.These results are also relevant for the construction of truncations in functional methods, as they provide hints on necessary properties to be retained in truncations.

View Article: PubMed Central - PubMed

Affiliation: Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria.

ABSTRACT

Two popular perspectives on the non-perturbative domain of Yang-Mills theories are either in terms of the gluons themselves or in terms of collective gluonic excitations, i.e. topological excitations. If both views are correct, then they are only two different representations of the same underlying physics. One possibility to investigate this connection is by the determination of gluon correlation functions in topological background fields, as created by the smearing of lattice configurations. This is performed here for the minimal Landau gauge gluon propagator, ghost propagator, and running coupling, both in momentum and position space for SU(2) Yang-Mills theory. The results show that the salient low-momentum features of the propagators are qualitatively retained under smearing at sufficiently small momenta, in agreement with an equivalence of both perspectives. However, the mid-momentum behavior is significantly affected. These results are also relevant for the construction of truncations in functional methods, as they provide hints on necessary properties to be retained in truncations.

No MeSH data available.