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user10354138's user avatar
user10354138's user avatar
user10354138
  • Member for 5 years, 2 months
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31 votes

"Naturally occurring" non-Hausdorff spaces?

21 votes
Accepted

Find the limit $\lim _{n \to \infty}(n!)^{{\frac{1}{n^2}}}$

19 votes

Proving this inequality without calculus

13 votes
Accepted

value of $\int_{-\infty}^{\infty}\arcsin\frac1{\cosh x}\,dx$

13 votes
Accepted

Understanding the distance between a line and a point in 3D space

12 votes
Accepted

The map from SU(4) to SO(6)

11 votes
Accepted

Well ordering principle for rationals

10 votes
Accepted

Does there exist a non-trivial group that is both perfect and complete?

10 votes
Accepted

Let $G$ be a finite group. If $a = bab$, is it true that $b^{2} = e$

9 votes

Fubini's theorem and reparameterisation

9 votes
Accepted

What is known about merely-orthogonal matrices?

9 votes
Accepted

What is the intuition behind pushouts and pullbacks in category theory?

9 votes
Accepted

$\sigma$-algebra generated by open balls

9 votes
Accepted

Infinite dimensional vector space

9 votes
Accepted

Calibrations vs. Riemannian holonomy

9 votes
Accepted

Strongest topology that makes vector space locally convex

9 votes
Accepted

Evaluating $\int_0^\infty\operatorname{erfi}(x)e^{-x^2}\frac{dx}x$

8 votes
Accepted

Is the set of continuous maps on $[0,1]$ with finitely many roots open in the $C^0$ topology?

8 votes
Accepted

Wish to evaluate $\int_{0}^{1}\frac{x^4-3x^2+2x}{\sin(\pi x)} dx$

8 votes
Accepted

What does $\text{Sp}(n)\cdot\text{Sp}(1)$ mean in Berger's holonomy list?

8 votes

If $\lim_{\alpha \to \infty}\alpha P[X > \alpha] = 0$ then $E[X] < \infty$?

8 votes
Accepted

Groups of order $252 = 4 \cdot 7 \cdot 9$ are solvable

7 votes
Accepted

$f$ continuous with derivative $f'(x)=0$ for all $x\in \mathbb{R}\setminus A$ where $A$ is countable implies $f$ constant

7 votes
Accepted

Is the intersection of an arbitrary set of finite sets with the finite intersection property nonempty?

7 votes
Accepted

Dual of an elliptic curve?

7 votes
Accepted

Evaluate $\sum_{r=1}^{502} \lfloor \frac{305r}{503} \rfloor$.

7 votes
Accepted

Fundamental group of the real projective plane and its universal cover

7 votes

Find the value of $a_4-a_2$

7 votes
Accepted

Does $G/H\cong \mathbb{Z}^n$ with $H\cong \mathbb{Z}^m$ imply that $G\cong \mathbb{Z}^{m+n}$?

7 votes
Accepted

need help solving a quartic equation

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