Although much of classical ergodic theory is concerned with single
transformations and one-parameter flows, the subject inherits from
statistical mechanics not only its name, but also an obligation to
analyze spatially extended systems with multidimensional symmetry
groups. However, the wealth of concrete and natural examples which has
contributed so much to the appeal and development of classical dynamics,
is noticeably absent in this more general theory. The purpose of this
book is to help remedy this scarcity of explicit examples by introducing
a class of continuous Zd-actions diverse enough to exhibit many of the
new phenomena encountered in the transition from Z to Zd, but which
nevertheless lends itself to systematic study: the Zd-actions by
automorphisms of compact, abelian groups. One aspect of these actions,
not surprising in itself but quite striking in its extent and depth
nonetheless, is the connection with commutative algebra and arithmetical
algebraic geometry. The algebraic framework resulting from this
connection allows the construction of examples with a variety of
specified dynamical properties, and by combining algebraic and dynamical
tools one obtains a quite detailed understanding of this class of
Zd-actions.