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Ville Salo
  • Member for 4 years, 3 months
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27 votes

For $x$ irrational, is $a_{n} =\sum_{k=1}^{n}(-1)^{⌊kx⌋}$ unbounded?

16 votes
Accepted

Structure theorems for compact sets of rationals

16 votes

Does Conway's game of life admit a notion of energy?

12 votes
Accepted

Homeomorphisms and "mod finite"

9 votes

Every mathematician has only a few tricks

7 votes
Accepted

What is the Borel complexity of this set?

7 votes
Accepted

Is a product of Følner sets Følner?

7 votes
Accepted

Is there an elementary proof that distal maps are invertible?

6 votes

Is there an elementary proof that distal maps are invertible?

6 votes
Accepted

Word combinatorics terminology question

6 votes

Do mixing homeomorphisms on continua have positive entropy?

5 votes

Can matrices over $F[G]$ have infinite order when $G$ is periodic?

5 votes
Accepted

Turing machines with all runs decidable

5 votes
Accepted

NP-hardness of a sequence problem

5 votes

A property for a group generated by involutions

5 votes
Accepted

Splendid groups

4 votes

The graph of Rule 110 and vertices degree

4 votes

Tiling with similar tiles

4 votes
Accepted

Connection between entropy and the set of factors of a sequence

4 votes

Busy Beaver in cellular automata

4 votes

Topological dynamical systems with only zero-entropy factors

3 votes

Cohomology for extension problems in symbolic/topological dynamics?

3 votes
Accepted

Is a “uniformly minimal” dynamical system ergodic?

3 votes

Algorithmically decide if an algorithm has optimal time complexity

3 votes
Accepted

Binary cellular automata: How slowly can an eroder remove $1$'s?

3 votes

Which groups contain a comb?

3 votes

Can a group be a universal Turing machine?

3 votes

What's the use of countable ordinals? (prompted by a remark of Tim Gowers)

3 votes

Følner sequences with weird shapes

2 votes

A detail about busy beaverly behavior of distortion functions in graph groups