Harry Altman's user avatar
Harry Altman's user avatar
Harry Altman's user avatar
Harry Altman
  • Member for 13 years, 5 months
  • Last seen more than a week ago
44 votes
Accepted

Are all $p$-adic number systems the same?

14 votes
Accepted

Entire function with $f(z)=\sin(f(z))$ must be constant?

11 votes
Accepted

Fixed points of a holomorphic map on a simply connected domain

8 votes

What is the importance of an integer sequence like the happy numbers?

7 votes

compose two functions to make them differentiable

7 votes
Accepted

Characteristic 3 analogue of nimbers?

7 votes
Accepted

Surprising places that particular countable ordinals show up.

6 votes

Shortest irreducible polynomials over $\Bbb F_p$ of degree $n$

6 votes

Can I build a finitely additive function on $\mathbb{Q}_p$?

5 votes
Accepted

Matrix of a linear transformation in upper triangular form

5 votes

An order type $\tau$ equal to its power $\tau^n, n>2$

4 votes
Accepted

Does a topological group need to have a uniformity making all group operations uniformly continuous?

4 votes
Accepted

Start with a topological group, take the meet of the two uniformities, and take the topology. Is the result again a topological group?

3 votes

Periodicity of $a_n={n \choose z}\ mod \ y$?

3 votes
Accepted

Show that $\mathcal{P}(X)\times\mathcal{P}(X)=\mathcal{P}(X\times X)$

3 votes

Is every finite category identifiable with a directed multigraph? (and vice versa?)

3 votes

property of a topological group

3 votes

Does a topological group need to have a uniformity making all group operations uniformly continuous?

3 votes
Accepted

What does "increases in proportion to" mean?

2 votes

Find all functions $f:\mathbb{R}^+\to \mathbb{R}^+$ such that for all $x,y\in\mathbb{R}^+$, $f(x)f(yf(x))=f(x+y)$

2 votes
Accepted

Given an ordinal with a particular cofinality, can we find other cofinal subsets with order type and cofinality at least that large?

2 votes
Accepted

Do the Moufang identities *themselves* imply diassociativity / Moufang's theorem / Artin's theorem?

2 votes
Accepted

An alternate proof of Egorov's Theorem

2 votes

Can $\sum_1^n 1/k$ be arranged so that it is an integer for infinitely many $n?$

1 vote
Accepted

Is this problem NP-complete?

1 vote

A topological space

1 vote

Proof that that $K=\mathbb{Q}$

1 vote
Accepted

Is this an alternate characterization of $\lambda$-rings? Or, what is like a $\lambda$-ring but for symmetric rather than exterior powers?

1 vote

Why is a polynomial also a rational function?

1 vote

Is identity the only function $f$ on real line satisfying $ f(x +f(y) + yf(x)) = y +f(x) + xf(y) ,\forall x,y \in \mathbb R$?