000 02347cam a2200241 a 4500
001 4489609
005 20250602151535.0
008 970604s1997 nyua b 001 0 eng
020 _a9780306455506
040 _aCSL
_cCSL
084 _aB316z7 N7 NBHM
_qCSL
100 1 _aAkin, Ethan.
_d1946-
_9811421
245 1 0 _aRecurrence in topological dynamics :
_bFurstenberg families and Ellis actions
260 _aNew York :
_bPlenum Press,
_c1997.
300 _aix, 265 p. :
_bill. ;
_c24 cm.
490 1 _aThe university series in mathematics
504 _aIncludes bibliographical references and index.
520 _aIn the long run of a dynamical system, after transient phenomena have passed away, what remains is recurrence. An orbit is recurrent when it returns repeatedly to each neighborhood of its initial position. We can sharpen the concept by insisting that the returns occur with at least some prescribed frequency. For example, an orbit lies in some minimal subset if and only if it returns almost periodically to each neighborhood of the initial point. That is, each return time set is a so-called syndetic subset ofT= the positive reals (continuous time system) or T = the positive integers (discrete time system). This is a prototype for many of the results in this book. In particular, frequency is measured by membership in a family of subsets of the space modeling time, in this case the family of syndetic subsets of T. In applying dynamics to combinatorial number theory, Furstenberg introduced a large number of such families. Our first task is to describe explicitly the calculus of families implicit in Furstenberg's original work and in the results which have proliferated since. There are general constructions on families, e. g. , the dual of a family and the product of families. Other natural constructions arise from a topology or group action on the underlying set. The foundations are laid, in perhaps tedious detail, in Chapter 2. The family machinery is then applied in Chapters 3 and 4 to describe family versions of recurrence, topological transitivity, distality and rigidity.
650 0 _aTopological dynamics.
_9811422
650 0 _aPoint mappings (Mathematics)
_9811423
830 0 _aUniversity series in mathematics
_9811424
942 _2CC
_n0
_cTEXL
_hB316z7 N7 NBHM
999 _c1431312
_d1431312