Phase Transition by 0-Branes of U(1) Lattice Gauge Theory
  The site reduction of U(1) lattice gauge theory is used to model the 0-branes in the dual theory. The reduced theory is the 1D plane-rotator model of the angle-valued coordinates on discrete world-line. The energy spectrum is obtained exactly via the transfer-matrix method, with a minimum in the lowest energy as a direct consequence of compact nature of coordinates. Below the critical coupling $g_c=1.125$ and temperature $T_c=0.335$ the system undergoes a first order phase transition between coexistent phases with lower and higher gauge couplings. The possible relation between the model and the proposed role for magnetic monopoles in confinement mechanism based on dual Meissner effect is pointed. 
Amir H. Fatollahi
hep-th