Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results for maximally almost periodic
Search options not deleted
7 votes
1 answer
463 views

Are countable FC-groups maximally almost periodic?

A group G is said to be maximally almost periodic if there is an injective homomorphism from G into a compact Hausdorff group. … My question is whether every discrete countable FC-group G is maximally almost periodic. …
Robin Tucker-Drob's user avatar
1 vote
0 answers
41 views

Do maximally almost periodic groups embed homeomorphically into their Bohr compactifications? [duplicate]

If $G$ is a Hausdorff topological group and $bG$ is its Bohr compactification, Wikipedia says that $G$ is called maximally almost periodic (MAP) if and only if the natural map $i : G \to bG$ is injective …
Alex M.'s user avatar
  • 5,407
3 votes
1 answer
223 views

Almost periodic functions and the property A

.$$ Now consider an almost periodic function $f$. … It is easy to see that hypothesis 1 is true for the periodic case. But I even don't know what to do with special almost periodic case. For the general case, i.e. …
demolishka's user avatar
1 vote

A certain class of representations

The buzzword to look for is "maximally almost periodic". This is part of the theory of Bohr Compactifications. Start with a (locally compact) group $G$. … By definition, this means that $G$ is "maximally almost periodic" (MAP). …
Matthew Daws's user avatar
  • 18.7k
3 votes
1 answer
211 views

About understanding manifold structure on WAP compactification of $\Bbb{C} \rtimes \Bbb{T}$

A continuous bounded function $f$ on $G$ is called (weakly) almost periodic if the set $L_Gf$ of left translates is relatively compact in the (weak) norm topology. … Then $f$ is uniformly continuous with respect to the left and right uniform structures on $G$ and all (weakly) almost periodic functions forms an abelian $C^*$-algebra with the norm of uniform convergence …
Mambo's user avatar
  • 185
2 votes
Accepted

Does each discrete solvable group admit an injective homomorphism to a compact topological g...

According to Proposition 3.3 from Dikranjan and Toller [Topology and its Applications 159 (2012) 2951-2972], the Heisenberg group H_K over an infinite field K of characteritic 0 is not maximally almostperiodic. …
user103213's user avatar
6 votes
0 answers
120 views

Aperiodic packings of the plane with disks of multiple radii

Does there exist a finite set of radii such that some aperiodic packing of the plane by disks of those radii is believed to achieve the maximal packing density (not achieved by any periodic packing)? … [Note to administrators: I wanted to add “aperiodic” or “quasicrystal” or something like that as a tag; I settled for “almost-periodic-function”, but please re-tag as appropriate.] …
James Propp's user avatar
  • 19.7k
19 votes

Countable subgroups of compact groups

As a complement to Reid's answer: a finitely generated group is maximally almost periodic if and only if it is residually finite. …
Alain Valette's user avatar
17 votes
Accepted

Countable subgroups of compact groups

Such groups are called "maximally almost periodic". Take a look at this paper for a more in-depth treatment. …
Reid Barton's user avatar
  • 25.2k
10 votes
0 answers
508 views

flexibility of almost contact ``Reeb'' vector fields

Can I deform the pair $(\alpha, \omega)$ so that the only minimal invariant sets of the resulting vector field are non-degenerate periodic orbits? … I am now allowing a larger family of deformations (since the 2-form is allowed to vary among maximally non-degenerate 2-forms, dropping the condition of being closed.) …
Sam Lisi's user avatar
  • 1,242
5 votes

Bohr compactification as a topological compactification

Note: I have restricted my answer to abelian $G$; $\iota$ can be defined for any topological group, but your question only makes sense when $\iota$ is injective, i.e. for “maximally almost-periodic” $G …
Francois Ziegler's user avatar
-2 votes
1 answer
116 views

Mismatch between equivalent definitions of the Bohr compactification of the reals

The maximal ideal space of the set $AP(\mathbb R)$ of almost periodic functions. i.e the set of multiplicative linear functionals under the pointwise topology. …
Daron's user avatar
  • 1,955
4 votes
1 answer
172 views

Compactness modulo symmetries of critical NLS solution

A function $u\in C_{t,loc}^{0}L_{x}^{2}(I\times\mathbb{R}^{N})$ is almost periodic modulo $G$ if the quotiented orbit $\{Gu(t) : t\in I\}$ is a precompact subset of $G\backslash L_{x}^{2}(\mathbb{R}^{N … Equivalently, $u$ is almost periodic modulo $G$ if there exists a compact subset $K\subset L_{x}^{2}(\mathbb{R}^{N})$ such that $u(t)\in GK$, $t\in I$. …
Matt Rosenzweig's user avatar
4 votes
1 answer
208 views

When entropy SRB measure is zero

The maximal open set $U$ with this property is called the basin of $f$. It is well known that every transitive Anosov diffeomorphism carries a unique SRB measure. … My solution : Let $p \in M$ be a periodic point associated to $\delta, S$ and $\{x, f(x),..., f^{n-1}(x)\}$ in the periodic exponential specification property. …
Adam's user avatar
  • 1,043
5 votes
Accepted

Bohr compactification as a topological compactification

unfortunate, as $u$ is not a compactification in the sense usually used in topology, unless $G$ was compact to begin with (in fact, $u$ is rarely injective - groups for which $u$ is injective are called "maximallyalmost periodic"). …
Uri Bader's user avatar
  • 11.6k

15 30 50 per page