Two spaces homeomorphic to Seq ( p )
نویسنده
چکیده
We consider the spaces called Seq(ut), constructed on the set Seq of all finite sequences of natural numbers using ultrafilters ut to define the topology. For such spaces, we discuss continuity, homogeneity, and rigidity. We prove that S(ut) is homogeneous if and only if all the ultrafilters ut have the same Rudin-Keisler type. We proved that a space of Louveau, and in certain cases, a space of Sirota, are homeomorphic to Seq(p) (i.e., ut = p for all t ∈ Seq). It follows that for a Ramsey ultrafilter p, Seq(p) is a topological group.
منابع مشابه
Orbit Spaces Arising from Isometric Actions on Hyperbolic Spaces
Let be a differentiable action of a Lie group on a differentiable manifold and consider the orbit space with the quotient topology. Dimension of is called the cohomogeneity of the action of on . If is a differentiable manifold of cohomogeneity one under the action of a compact and connected Lie group, then the orbit space is homeomorphic to one of the spaces , , or . In this paper we suppo...
متن کاملBanach Spaces Determined by Their Uniform Structures
Following results of Bourgain and Gorelik we show that the spaces lp, 1 < p < ∞, as well as some related spaces have the following uniqueness property: If X is a Banach space uniformly homeomorphic to one of these spaces then it is linearly isomorphic to the same space. We also prove that if a C(K) space is uniformly homeomorphic to c0, then it is isomorphic to c0. We show also that there are B...
متن کاملAn example of $,-equivalent spaces which are not &-equivalent
We construct an example of two countable spaces X and Y such that the spaces C,‘(X) and CG (Y) are homeomorphic and the spaces C,(X) and C,(Y) are not homeomorphic. o 1998 Elsevier Science B.V.
متن کاملThe Uniform Classification of Banach Spaces
This is a survey of results on the classification of Banach spaces as metric spaces. It is based on a series of lectures I gave at the Functional Analysis Seminar in 1984-1985, and it appeared in the 1984-1985 issue of the Longhorn Notes. I keep receiving requests for copies, because some of the material here does not appear elsewhere and because the Longhorn Notes are not so easy to get. Havin...
متن کاملSpaces of Uncountably Many Dimensions*
Riemann in his Habilitations Schrift of 1854 suggested the notion of ^-dimensional space (where n is a natural number) as an extension of the notion of three-dimensional euclidean space. Hubert extended the notion still further by defining a space of a countably infinite number of dimensions. Fréchetf in 1908 defined two other spaces of countably many dimensions, which he called D„ and J3W. Tyc...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2010