Automorphisms of Homogeneous Structures
نویسندگان
چکیده
منابع مشابه
Turbulence, Amalgamation, and Generic Automorphisms of Homogeneous Structures
We study topological properties of conjugacy classes in Polish groups, with emphasis on automorphism groups of homogeneous countable structures. We first consider the existence of dense conjugacy classes (the topological Rokhlin property). We then characterize when an automorphism group admits a comeager conjugacy class (answering a question of Truss) and apply this to show that the homeomorphi...
متن کاملSe p 20 04 Turbulence , amalgamation and generic automorphisms of homogeneous structures
(A) We study in this paper topological properties of conjugacy classes in Polish groups. There are two questions which we are particularly interested in. First, does a Polish group G have a dense conjugacy class? This is equivalent (see, e.g., Kechris [95, 8.47]) to the following generic ergodicity property of G: Every conjugacy invariant subset A ⊆ G with the Baire property (e.g., a Borel set)...
متن کاملct 2 00 4 Turbulence , amalgamation and generic automorphisms of homogeneous structures
We study topological properties of conjugacy classes in Polish groups, with emphasis on automorphism groups of homogeneous countable structures. We first consider the existence of dense conjugacy classes (the topological Rokhlin property). We then characterize when an automorphism group admits a comeager conjugacy class (answering a question of Truss) and apply this to show that the homeomorphi...
متن کاملHomogeneous Structures
A relational first order structure is homogeneous if every isomorphism between finite substructures extends to an automorphism. Familiar examples of such structures include the rational numbers with the usual order relation, the countable random and so called Rado graph, and many others. Countable homogeneous structures arise as Fraı̈ssé limits of amalgamation classes of finite structures, and h...
متن کاملHomogeneous structures, . . .
I aim to give the flavour of a selection of topics based around Fräıssé’s notion of homogeneous structure. This is an area connecting ideas from model theory, permutation group theory, combinatorics, descriptive set theory, complexity theory, and other subjects. I will touch superficially a number of these subjects, with little in depth. The background assumed will be basic first order logic (l...
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: Notre Dame Journal of Formal Logic
سال: 2005
ISSN: 0029-4527
DOI: 10.1305/ndjfl/1134397660