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 tagged with
Search options not deleted user 12978

Dynamics of flows and maps (continuous and discrete time), including infinite-dimensional dynamics, Hamiltonian dynamics, ergodic theory.

1 vote
1 answer
171 views

Extension of power bounded operators over a finite subspace

Suppose $Y$ is a Banach space and $X$ is a finite-dimensional subspace of $Y$. Further assume $T:X \rightarrow X$ is a linear operator which is power bounded from above and below, in other words ther …
Jason Rute's user avatar
  • 6,287
5 votes
2 answers
434 views

Sz.-Nagy dilation for uniformly convex Banach spaces

The Sz.-Nagy dilation theorem says that for a Hilbert space $H$ with nonexpansive operator $T$, there is a larger space $H'$ containing $H$ and a unitary operator $U$ on $H'$ such that for all $x \in …
Jason Rute's user avatar
  • 6,287
9 votes
2 answers
745 views

Is this ergodic inequality true?

Is anything similar to the following inequality true, $\displaystyle P\{\max_{n \leq k \leq m} |A_k f - A_n f| > \epsilon\} \leq C \frac{||A_m f - A_n f||_1}{\epsilon}$ where $A_n f = \frac{\sum …
Jason Rute's user avatar
  • 6,287
11 votes
2 answers
2k views

De Finetti's theorem, the pointwise ergodic theorem, and reverse martingales

De Finetti's theorem says that an exchangeable sequence of random variables $X_i$ is a mixture of i.i.d. random variables. In other words, if $\mu$ is a measure on $\mathbb{R}^\infty$ that is invaria …
Jason Rute's user avatar
  • 6,287
5 votes

De Finetti's theorem, the pointwise ergodic theorem, and reverse martingales

(My understanding of this material has significantly gone up in the months since I asked it, and I will attempt to answer my own question.) In general, if $(\Omega,\mathcal{B},\mathbb{P},\{T_g\})$ is …
Jason Rute's user avatar
  • 6,287
38 votes
1 answer
3k views

Is the area of the Mandelbrot provably computable?

Recall the Mandelbrot set $M$ is the set of points $c$ in the complex plane such that the sequence $z_0 = 0, z_{n+1} = z_n^2 + c$ is bounded. It is well-known that $M$ is a compact set of positive ar …
Jason Rute's user avatar
  • 6,287