Calorons and BPS monopoles with non-trivial holonomy in the confinement   phase of SU(2) gluodynamics
  With the help of the cooling method applied to SU(2) lattice gauge theory at non-zero $T \le T_c$ we present numerical evidence for the existence of superpositions of Kraan-van Baal caloron (or BPS monopole pair) solutions with non-trivial holonomy, which might constitute an important contribution to the semi-classical approximation of the partition function. 
E.-M. Ilgenfritz, B.V. Martemyanov, M. Muller-Preussker, S.   Shcheredin, A.I. Veselov