Quantum chaos at finite temperature

We use the quantum action to Study quantum chaos at finite temperature. We present a numerical study of a classically chaotic 2-D Hamiltonian system - harmonic oscillators with anharmonic coupling. We construct the quantum ac tion nonperturbatively and find temperature-dependent quantum corrections i n the action parameters. We compare Poincare sections of the quantum action at finite temperature with those of the classical action. (C) 2001 Elsevie r Science B.V. All rights reserved.