Screening and D-brane dynamics in finite temperature superstring theory - art. no. 106009

The thermodynamics of D-branes and of open superstrings in background gauge fields is studied. It is shown that D-brane dynamics forbids constant velo city motion at finite temperature. T duality is used to interpret this feat ure as a consequence of the absence of an equilibrium state of charged stri ngs at finite temperature in a constant background electric field, as a res ult of Debye screening of electric fields. The effective action for the Pol yakov loop operator is computed and the corresponding screening solutions a re described. The finite temperature theory is also used to illustrate the importance of carefully incorporating Wu-Yang terms into the string path in tegral for compact target spaces. [S0556-2821(99)00722-5].