Let A be an exact C*-algebra, let G be a locally compact group, and let (A, G, alpha) be a C*-dynamical system. Each automorphism alpha(g) induces a spatial automorphism Ad(lambdag) on the reduced crossed product A x(alpha) G. In this paper we examine the question, first raised by E. Stormer, of when the topological entropies of alpha(y) and Ad(lambdag) coincide. This had been answered by N. Brown for the particular case of discrete abelian groups. Using different methods, we extend his result to preservation of entropy for alpha(y) when the subgroup of Aut(G) generated by the corresponding inner automorphism Ad(g) has compact closure. This property is satisfied by all elements of a wide class of groups called locally [FIA](-). This class includes all abelian groups, both discrete and continuous, as well as all compact groups. (C) 2003 Elsevier Science (USA). All rights reserved. [References: 23]
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