Vacuum structure as seen by overlap fermions

Abstract

Abstract. Three complementary views on the QCD vacuum structure, all based on eigenmodes of the overlap operator, are reported in their interrelation: (i) spectral density, localization and chiral properties of the modes, (ii) the possibility of filtering the field strength with the aim to detect selfdual and antiselfdual domains and (iii) the various faces of the topological charge density, with and without a cutoff λ cut = O(Λ QCD ). The techniques are tested on quenched SU(3) configurations.

Dyonic picture of topological objects in the deconfined phase

“…The fermionic eigenmodes (and their spectral density) show some striking peculiarities above T c that our dyonic picture of the topological content of SU (2) lattice gauge theory seems to be able to explain. In the time since our paper [11] was written, our own analysis of topological objects by means of overlap fermions has progressed and concentrated on the hightemperature phase, not only on properties of individual overlap modes, but also on the possibility to extract [13] topological properties of the gauge field. In this paper we present the analysis of topological clusters above T c which again requires to use the UV filtered definition of the topological density.…”

“…IV we investigate topological clusters and their respective degree of (anti-)selfduality following the idea of Ref. [14] by constructing the topological charge density and the field strength tensor [13] in an UV filtered way from the lowest fermion eigenmodes. In Sect.…”

Center vortex model for the infrared sector of SU(3) Yang-Mills theory: Topological susceptibility

“…These findings have been complemented by further recent investigations focusing on correlations between center vortices and low-lying overlap Dirac operator eigenmodes [21][22][23], which, on the other hand, can be tied to the topological charge density. Of related interest are studies of the connection between center vortices and other topological charge carriers arising in Yang-Mills theory; a detailed analysis of the vortex content of calorons was presented recently in [32].…”

“…Two main lines of investigation have contributed to these developments. On the one hand, sparked by the inception of practicable algorithms for the detection of vortices in lattice Yang-Mills configurations [15][16][17], lattice studies of the vortex content of Yang-Mills theory and the effects it induces were carried out [15][16][17][18][19][20][21][22][23]. On the other hand, an infrared effective model based directly on center vortex degrees of freedom with a simplified effective dynamics was introduced to complement the lattice studies and expand on the range of vortex physics that could be accessed quantitatively [24][25][26][27][28][29][30][31].…”

Analysis of topological structure of the QCD vacuum with overlap-Dirac operator eigenmode

“…In this paper, we study the space-time profile of the low-lying overlap-Dirac eigenmodes using the eigenmode decomposition of a field strength tensor F µν [10,11]. In order to discuss the effect of valence quarks, we also investigate a spatial distribution of the action density and chiral condensate around the static color sources.…”