On the topological content of SU(2) gauge fields below T_c

Finite temperature Euclidean SU(2) lattice gauge elds generated in the connement phase close to the deconnement phase transition are subjected to cooling. The aim is to identify long-living, almost-classical local excitations which carry (generically non-integer) topological charge. Two kinds of spatial boundary conditions (xed holonomy and standard periodic boundary conditions) are applied. For the lowest-action almost-classical congurations we nd that their relative probability semi-quantitatively agrees for both types of boundary conditions. We nd calorons with unit topological charge as well as (anti-)selfdual lumps (BPS-monopoles or dyons) combined in pairs of non-integer (equal or opposite sign) topological charge. For calorons and separated pairs of equal-sign dyons obtained by cooling we have found that (i) the gluon eld is well-described by Kraan-van Baal solutions of the Euclidean Yang-Mills eld equations and (ii) the lowest Wilsonfermion modes are well-described by analytic solutions of the corresponding Dirac equation. For metastable congurations found at higher action, the multi-center structure can be interpreted in terms of dyons and antidyons, using the gluonic and fermionic indicators as in the dyon-pair case. Additionally, the Abelian monopole structure and eld strength correlators between the centers are useful to analyse the congurations in terms of dyonic constituents. We argue that a semi-classical approximation of the non-zero temperature path integral should be built on superpositions of solutions with non-trivial holonomy.