Quantum (in)stability of a brane-world AdS(5) universe at nonzero temperature

We consider the quantum effects of bulk matter (scalars, spinors) in the Ra ndall-Sundrum AdS(5) brane-world at nonzero temperature. The thermodynamic energy (modulus potential) is evaluated at low and high temperatures. This potential has an extremum which could be a minimum in some cases (for examp le, for a single fermion). That suggests a new dynamical mechanism to stabi lize the thermal AdS5 brane-world. It is shown that the brane separation re quired to solve the hierarchy scale problem may occur at a quite low temper ature. A natural generalization in terms of the AdS/CFT correspondence (thr ough the supergravity thermal contribution) is also possible. (C) 2001 Publ ished by Elsevier Science B.V.