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Riccardo.Alestra
  • Member for 12 years, 3 months
  • Last seen more than a week ago
  • Rome, RM, Italia
32 votes
2 answers
2k views

Can every curve on a Riemannian manifold be interpreted as a geodesic of a given metric?

29 votes
4 answers
2k views

Polygamma function series: $\sum_{k=1}^{\infty }\left(\Psi^{(1)}(k)\right)^2$

14 votes
1 answer
3k views

Sum of powers and prime numbers

14 votes
4 answers
398 views

Calculation of a strange series

13 votes
6 answers
3k views

A strange puzzle having two possible solutions

11 votes
1 answer
2k views

A question about Riemann curvature tensor and metric tensor

9 votes
4 answers
2k views

Show $\lim_{N\to \infty}\sum_{k=1}^{N}\frac{1}{k+N}=\ln(2)$

9 votes
0 answers
340 views

Limit of a product of trigonometric functions [closed]

8 votes
4 answers
172 views

Matrix equation $A^2+A=I$ when $\det(A) = 1$

8 votes
1 answer
1k views

Trace of a differential operator

7 votes
2 answers
427 views

About the infinite solutions of a Diophantine equation

7 votes
1 answer
816 views

A question concerning on the axiom of choice and Cauchy functional equation

7 votes
2 answers
1k views

Integral of a function defined in the set of Surreal Numbers

7 votes
2 answers
201 views

Evaluating the sum: $S_n=\sum_{k=1}^\infty\dfrac{k^n}{(k!)^2}$

7 votes
1 answer
3k views

Limit of the sum $\sum_{k=1}^\infty\frac{\sin(kx)}{kx}$

7 votes
3 answers
239 views

Proving the exponential inequality: $x^y+y^x\gt1$

6 votes
1 answer
599 views

Geodesic on a Riemannian manifold with a random metric tensor

6 votes
3 answers
166 views

Bound for $\sum_{k=1}^\infty\left(\frac{1}{2^k+k^2}\right)$

6 votes
1 answer
3k views

Is the Mellin transform useful to solve differential equations?

6 votes
1 answer
530 views

Complex derivative

5 votes
2 answers
1k views

PDE involving curl

5 votes
4 answers
516 views

Closed form solutions of $\ddot x(t)-x(t)^n=0$

5 votes
1 answer
228 views

Anomalous integral equation

5 votes
1 answer
406 views

binary-decimal primes

5 votes
3 answers
568 views

Integral equation with a constraint

5 votes
2 answers
1k views

A problem with Cantor's continuum hypothesis

5 votes
2 answers
736 views

Heat equation with an unknown diffusion coefficient

5 votes
1 answer
211 views

Evaluation of the definite integral $\int_0^{\pi/2}x\tan(x)^pdx$ [closed]

5 votes
3 answers
321 views

Proof that $\sum\limits_{j,k=1}^N\frac{a_ja_k}{j+k}\ge0$

5 votes
2 answers
166 views

Is this sum $S=\sum_{i,j=1}^n\frac{a_ia_j}{i+j}$ greater than or equal to zero?

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