Extensions of Boolean isometries
نویسندگان
چکیده
منابع مشابه
Extensions of Boolean isometries
We study when a map between two subsets of a Boolean domain W can be extended to an automorphism of W . Under many hypotheses, if the underlying Boolean algebra is complete or if the sets are finite or Boolean domains, the necessary and sufficient condition is that it preserves the Boolean distance between every couple of points.
متن کاملExtensions of Free Boolean Algebras
In a series of papers [2, 3, 4, 5], B. Efimov has given sufficient conditions for a Boolean algebra to have a free subalgebra of given cardinality. For example, he has shown that if an infinite Boolean algebra A has cardinality greater than exp exp exp v, but the supremum of the cardinalities of subsets of disjoint elements in A is not greater than v, then A has a free subalgebra with (exp v) i...
متن کاملBoolean Automorphisms of a Hypercube Coincide with the Linear Isometries
Boolean homomorphisms of a hypercube, which correspond to the morphisms in the category of finite Boolean algebras, coincide with the linear isometries of the category of finite binary metric vector spaces.
متن کاملSpatial Models of Boolean Actions and Groups of Isometries
Given a Polish group G of isometries of a locally compact separable metric space, we prove that each measure preserving Boolean action by G has a spatial model or, in other words, has a point realization. This result extends both a classical theorem of Mackey and a recent theorem of Glasner and Weiss, and it covers interesting new examples. In order to prove our result, we give a characterizati...
متن کاملFiber respecting quasi-isometries of surface group extensions
Let S be a closed, oriented surface of genus g ≥ 2, and consider the extension 1 → π1S → MCG(S, p) → MCG(S) → 1, where MCG(S) is the mapping class group of S, and MCG(S, p) is the mapping class group of S punctured at p. We prove that any quasi-isometry of MCG(S, p) which coarsely respects the cosets of the normal subgroup π1S is a bounded distance from the left action of some element of MCG(S,...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Discrete Mathematics
سال: 2005
ISSN: 0012-365X
DOI: 10.1016/j.disc.2005.04.011