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feralin
  • Member for 9 years, 8 months
  • Last seen more than 2 years ago
32 votes
4 answers
3k views

Is there any uncountably infinite set that does not generate the reals?

20 votes
3 answers
906 views

Are certain integer functions well-defined modulo different primes necessarily polynomials?

9 votes
2 answers
2k views

Confusion about contour integration of constant function: intuition vs. Residue Theorem

7 votes
2 answers
2k views

Are there prime gaps of every size?

7 votes
1 answer
119 views

Is the growth rate of certain sets in $\mathbb Z$ is eventually linear?,

6 votes
2 answers
277 views

Is inversion of bounded homeomorphisms continuous with the uniform metric?

5 votes
4 answers
1k views

Upper bound on integral: $\int_1^\infty \frac{dx}{\sqrt{x^3-1}} < 4$

5 votes
1 answer
122 views

Prove that if $n \mid 1 + \sum_{k=0}^{n-1} k^{n-1}$ then $n$ is prime.

4 votes
1 answer
175 views

Are there injective maps from a higher- to a lower-dimensional cellular automaton?

4 votes
0 answers
38 views

What is $F / F_{fin}$ isomorphic to, where $F$ is the group of integer functions and $F_{fin}$ is the subgroup of finitely-supported functions?

3 votes
0 answers
106 views

Is inversion a continuous function in a space of homeomorphisms?

3 votes
1 answer
156 views

Evaluating $\sum_{n=1}^{\infty} \frac{4(-1)^n}{1-4n^2}$

3 votes
1 answer
48 views

Does every function $X^n \to Y$ for $X, Y$ finite extend to a linear transformation between finite vector spaces?

2 votes
2 answers
184 views

What is the Smallest Integer $N$ Where Reversing the Digits Makes $3N$?

2 votes
1 answer
837 views

What's wrong with my "proof" of the Cayley-Hamilton Theorem? [duplicate]

2 votes
2 answers
52 views

What is $mA$, where $m \in \mathbb N$ and $A$ is a group?

2 votes
1 answer
65 views

Covering almost all naturals by translates of a set

2 votes
2 answers
47 views

Is every function between finite sets a restriction of a morphism of finite abelian groups (up to bijection)?

2 votes
0 answers
41 views

For which rings $S \leq R$ do we have $S \cap R^\times = S^\times$?

2 votes
1 answer
75 views

Solutions to $\phi(f) = 0$ when $\phi$ is a 2d discrete convolution.

2 votes
1 answer
42 views

For what translation groups $G$ of $\mathbb C$ is $\mathbb C / G$ compact?

2 votes
0 answers
93 views

Are there any finitely-supported functions in the kernel of a particular homomorphism?

2 votes
0 answers
39 views

Is there a squarefree number between any two squares? [duplicate]

1 vote
1 answer
153 views

Sum of powers congruence

1 vote
1 answer
270 views

Are the units of a monoid-graded ring homogeneous?

1 vote
1 answer
99 views

Is $\mathbb{P}^1(\mathbb R)$ an abelian variety?

1 vote
0 answers
662 views

Proper definition of coordinate ring?

1 vote
3 answers
642 views

Prove that $\mathbb R$ is not a nontrivial disjoint union of open subsets.

1 vote
2 answers
226 views

Prove that a non-constant rational function on a variety has an infinite image

1 vote
1 answer
70 views

Given a field extension $L : K : F$, if $L:F$ and $K:F$ are finitely generated then so is $L:K$.