Skip to main content
Olivier Bégassat's user avatar
Olivier Bégassat's user avatar
Olivier Bégassat's user avatar
Olivier Bégassat
  • Member for 13 years
  • Last seen this week
  • France
27 votes
Accepted

orientability of riemann surface

27 votes

On surjectivity of exponential map for Lie groups

21 votes
Accepted

Is there any difference between Bounded and Totally bounded?

20 votes
Accepted

A non-abelian group such that $G/Z(G)$ is abelian.

19 votes
Accepted

Reference for Lie-algebra valued differential forms

19 votes

Compact operators on an infinite dimensional Banach space cannot be surjective

17 votes
Accepted

Simple group of order $660$ is isomorphic to a subgroup of $A_{12}$

15 votes
Accepted

Is it possible for a closed manifold to deformation retract onto a proper subset of itself?

14 votes

Show that $\left(1+\dfrac{1}{n}\right)^n$ is monotonically increasing

14 votes
Accepted

Uncountable dense subset whose complement is also uncountable and dense

14 votes

Why is $\operatorname{Hom}(M,N)$ not necessarily an $R$ module?

14 votes
Accepted

If $a_i\geq 0,$ prove $\sum\limits_{n=1}^\infty\frac{a_1+a_2+\cdots+a_n}{n}$diverges.

12 votes

Proof of Proposition 2.4 in Atiyah-MacDonald

12 votes
Accepted

Prove that $\{\frac{\phi (n)}{n}\}_{n \in \Bbb N}$ is dense in $[0,1]$

12 votes
Accepted

Flat connection with non-trivial holonomy? I cannot get it

12 votes
Accepted

Redundance of the Smoothness of the Inversion Map in the Definition of a Lie Group.

12 votes
Accepted

Looking For a Neat Proof of the Fact that the Grassmannian Manifold is Hausdorff

11 votes
Accepted

If $h : Y \to X$ is a covering map and $Y$ is connected, then the cardinality of the fiber $h^{-1}(x)$ is independent of $x \in X$.

11 votes

Why are the fundamental groups $\pi_{1}(S^3)$ and $\pi_{1}(S^2)$ trivial?

11 votes
Accepted

Klein Bottle Embedding on $\mathbb{R}^4$.

10 votes

Product of $T_1$ spaces is $T_1$

10 votes

Topological distinguishibilty of $\infty$ after one point compactification?

10 votes
Accepted

Map from $n$-sphere to $n$ dimensional torus

10 votes
Accepted

"Why" is $[\mathbb{C}:\mathbb{R}] < \infty$?

10 votes

convergence of $\sum_{n=1}^\infty \frac{1}{(n!)^{(2/n)}}$

9 votes
Accepted

Example of nonvanishing vector field on SLn(R)

9 votes

In what sense can the Lie algebra of $GL_n(\mathbb{C})$ be "identified" with $M_n(\mathbb C)$?

9 votes
Accepted

Homeomorphisms of X form a topological group

9 votes
Accepted

How to find lagrangian submanifolds.

9 votes
Accepted

Are there counter intuitive interpretations of ZF or ZFC?

1
2 3 4 5
12