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The Relative Growth of Information. Aimee S. A. Johnson Swarthmore College joint with Karma Dajani, Universiteit Utrecht Martijn de Vries, Technische Universiteit Delft. Given. Scenario. Given Express as decimal expansion. Scenario. Given Express as decimal expansion
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The Relative Growth of Information Aimee S. A. Johnson Swarthmore College joint with Karma Dajani, Universiteit Utrecht Martijn de Vries, Technische Universiteit Delft
Given . Scenario
Given Express as decimal expansion . . Scenario
Given Express as decimal expansion continued fraction expansion . . . Scenario
Given Express as decimal expansion continued fraction expansion Question: Given first n digits in decimal exp, how many digits are known in continued fraction expansion? . . . Scenario
, Rephrase: Given x starts with What is largest m=m(n,x) s.t. we know x starts with Lochs’ Theorem:
, Rephrase: Given x starts with What is largest m=m(n,x) s.t. we know x starts with Lochs’ Theorem: for a.e. x,
Rephrase: Given x starts with What is largest m=m(n,x) s.t. we know x starts with Lochs’ Theorem:
Dynamical Systems Viewpoint Bosma, Dajani, Kraaikamp Dajani, Fieldsteel
Consider Dynamical Systems Viewpoint Bosma, Dajani, Kraaikamp Dajani, Fieldsteel
Consider Dynamical Systems Viewpoint Bosma, Dajani, Kraaikamp Dajani, Fieldsteel
Consider Partition P Dynamical Systems Viewpoint Bosma, Dajani, Kraaikamp Dajani, Fieldsteel
Consider PartitionP ._._._._._._._._._._. 0 .5 1 Dynamical Systems Viewpoint Bosma, Dajani, Kraaikamp Dajani, Fieldsteel
Consider Or Partition P ._._._._._._._._._._. 0 .5 1 Dynamical Systems Viewpoint Bosma, Dajani, Kraaikamp Dajani, Fieldsteel
Consider Or Partition P ._._._._._._._._._._. 0 .5 1 Partition Q .__._._.__.______. 0 .2 .25 .33 .5 1 Dynamical Systems Viewpoint Bosma, Dajani, Kraaikamp Dajani, Fieldsteel
Let e.g. and Same for Question:
Tools • Generating partition a.e. x≠y, there exists n s.t • Ergodic transformations • Entropy nonnegative number which indicates amount of uncertainty in system = hλ(S) • Shannon-McMillan-Breiman Theorem For T ergodic, P generating, a.e. x,
Theorem Given 2 ergodic dynamical systems on [0,1) with generating interval partitions P and Q, with entropies c and d, for a.e. x,
Theorem Given 2 ergodic dynamical systems on [0,1) with generating interval partitions P and Q, with entropies c and d, for a.e. x, e.g.
Higher Dimensions • . • Assumptions • . • . • .
Theorem • Given 2 ergodic dynamical systems on with generating partitions P and Q with entropies c and d, Then for a.e. x,
Vague idea of proof Let M= When wouldn’t m(n,x) = M?
Vague idea of proof Let M= When wouldn’t m(n,x) = M? bad points; where where x in is “frame” of
Vague idea of proof Let M= When wouldn’t m(n,x) = M? bad points; where where x in is “frame” of So msr of bad pts ≤ msr of frames ≈ k
Vague idea of proof Let M= When wouldn’t m(n,x) = M? bad points; where where x in is “frame” of So msr of bad pts ≤ msr of frames ≈ k So Σ(bad pts at nth stage) < So a.e. x leaves bad set eventually
With thanks to the organizers of the MSRI Connections for Women, January 2007