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Andrea Marino
  • Member for 7 years, 9 months
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14 votes
Accepted

Is the "cyclotomic diagonalization" always squarefree?

11 votes
Accepted

Prove $7^{71}>75^{32}$

5 votes
Accepted

For finite $A$: $f$ injective implies $f$ surjective

5 votes
Accepted

Prove that $\sum_{n=1}^{\infty}\frac{q^n}{1+q^{2n}}=\sum_{n=1}^{\infty}(d_1(n)-d_3(n))q^n$

5 votes
Accepted

Category of sheaves on a topological space is not $\mathbf{AB4^{*}}$

5 votes

Why the fundamental group of the circle is not trivial?

5 votes

Is (Inverse) Fourier Transform still a "sum" of sinusoids?

5 votes

An eely function $\mu (n):\;\;\prod\limits_{k = 0}^{n - 1} {\left( {\mu (n) - \mu (k)} \right)} = 1$

5 votes

The proofs of limit laws and derivative rules appear to tacitly assume that the limit exists in the first place

4 votes

If two polynomials in a single variable t, agree for all primes t, then they agree as polynomials

4 votes
Accepted

If $A^3 = 2I$, prove that matrix $A - 2^{\frac{1}{3}}I$ is not invertible

4 votes
Accepted

Defining higher homotopy in terms of embeddings $S^n \hookrightarrow X$?

4 votes

Can a sum of consecutive $n$th powers ever equal a power of two?

4 votes
Accepted

Algebraic Tensor product of Hilbert spaces

4 votes

What is an intuitive Geometrical explanation of a "sheaf?"

4 votes
Accepted

Number of smooth numbers less than x

4 votes
Accepted

Is map $f:\mathbb{D}^2\to \mathbb{S}^2$ that fix $\partial \mathbb{D}^2$ surjective on a hemisphere?

4 votes

Probability that the number of heads is coprime with the number of throws

3 votes

Is a connected groupoid uniquely determined by its objects and fundamental group?

3 votes

Do all Cauchy sequences in incomplete metric spaces have "natural limits" that simply lie outside the space?

3 votes
Accepted

Are $\Bbb Q/2 \Bbb Z$ and $\Bbb Q/5 \Bbb Z$ isomorphic as groups?

3 votes
Accepted

Express a function $g$ in the vector space $\mathbb{Z}/3$

3 votes

Is this a circular proof of Pythagorean Theorem? If not, are there better ones?

3 votes
Accepted

Topology of "degenerate spectrum submanifold" in the space of hermitian matrices

3 votes
Accepted

Showing that $\pi_1(X/G) \cong G$.

3 votes
Accepted

Finite ring extensions doesn't preserve non-zero-divisors

3 votes
Accepted

If you choose two different sets of results to match inside a coin flipping record, does the odds of finding a match depend on what you pick on each?

3 votes

Is every harmonic polynomial a linear combination of these?

2 votes
Accepted

$i : X^{n} \hookrightarrow X$ is a cofibration

2 votes

Why is the sum of all the elements in a subgroup generated by $10$ of $\Bbb Z_p$ is divisible by $p$

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