Outputs (80)

Automorphisms of Z^d-subshifts of finite type (1994)
Journal Article
Ward, T. (1994). Automorphisms of Z^d-subshifts of finite type. Indagationes Mathematicae, 5(4), 495-504. https://doi.org/10.1016/0019-3577%2894%2990020-5

Let (S,s) be a Z^d-subshift of finite type. Under a strong irreducibility condition (strong specification), we show that Aut(S) contains any finite group. For Z^d-subshifts of finite type without strong specification, examples show that topological m... Read More about Automorphisms of Z^d-subshifts of finite type.

An algebraic obstruction to isomorphism of Markov shifts with group alphabets (1993)
Journal Article
Ward, T. (1993). An algebraic obstruction to isomorphism of Markov shifts with group alphabets. Bulletin of the London Mathematical Society, 25(3), 240-246. https://doi.org/10.1112/blms/25.3.240

Mixing automorphisms of compact groups and a theorem of Schlickewei (1993)
Journal Article
Schmidt, K., & Ward, T. (1993). Mixing automorphisms of compact groups and a theorem of Schlickewei. Inventiones Mathematicae, 111(1), 69-76. https://doi.org/10.1007/bf01231280

We prove that every mixing Z^d-action by automorphisms of a compact, connected, abelian group is mixing of all orders.

Periodic points for expansive actions of Z^d on compact abelian groups (1992)
Journal Article
Ward, T. (1992). Periodic points for expansive actions of Z^d on compact abelian groups. Bulletin of the London Mathematical Society, 24(4), 317-324. https://doi.org/10.1112/blms/24.4.317

In this note we show that the periodic points of an expansive Z^d action on a compact abelian group are uniformly distributed with respect to Haar measure if the action has completely positive entropy. In the general expansive case, we show that any... Read More about Periodic points for expansive actions of Z^d on compact abelian groups.

The Abramov-Rokhlin entropy addition formula for amenable group actions (1992)
Journal Article
Ward, T., & Zhang, Q. (1992). The Abramov-Rokhlin entropy addition formula for amenable group actions. Monatshefte für Mathematik, 114(3-4), 317-329. https://doi.org/10.1007/bf01299386

In this note we show that the entropy of a skew product action of a countable amenable group satisfies the classical formula of Abramov and Rokhlin.

The Bernoulli property for expansive Z^2 actions on compact groups (1992)
Journal Article
Ward, T. (1992). The Bernoulli property for expansive Z^2 actions on compact groups. Israel Journal of Mathematics, 79(2-3), 225-249. https://doi.org/10.1007/bf02808217

We show that an expansive Z^2 action on a compact abelian group is measurably isomorphic to a two-dimensional Bernoulli shift if and only if it has completely positive entropy. The proof uses the algebraic structure of such actions described by Kitch... Read More about The Bernoulli property for expansive Z^2 actions on compact groups.

Almost block independence for the three dot Z^2 dynamical system (1991)
Journal Article
Ward, T. (1991). Almost block independence for the three dot Z^2 dynamical system. Israel Journal of Mathematics, 76(1-2), 237-256. https://doi.org/10.1007/bf02782855

Mahler measure and entropy for commuting automorphisms of compact groups (1990)
Journal Article
Lind, D., Schmidt, K., & Ward, T. (1990). Mahler measure and entropy for commuting automorphisms of compact groups. Inventiones Mathematicae, 101(1), 593-629. https://doi.org/10.1007/bf01231517

Automorphisms of solenoids and p-adic entropy (1988)
Journal Article
Lind, D., & Ward, T. (1988). Automorphisms of solenoids and p-adic entropy. Ergodic Theory and Dynamical Systems, 8(3), 411-419. https://doi.org/10.1017/s0143385700004545

We show that a full solenoid is locally the product of a euclidean component and p-adic components for each rational prime p. An automorphism of a solenoid preserves these components, and its topological entropy is shown to be the sum of the euclidea... Read More about Automorphisms of solenoids and p-adic entropy.

The entropy of automorphisms of solenoidal groups (1986)
Thesis
Ward, T. The entropy of automorphisms of solenoidal groups. (Dissertation). Department of Mathematics, University of Warwick. https://durham-repository.worktribe.com/output/1695418