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coudy
  • Member for 13 years, 10 months
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7 votes
0 answers
300 views

A citation from Dieudonné about existence, classification and construction

3 votes
1 answer
148 views

Sheaves and gratings

7 votes
0 answers
277 views

Dehn and the Jordan curve theorem

1 vote
1 answer
150 views

Homology of complements and homotopy equivalence

8 votes
2 answers
585 views

Pairs of elementary Fourier transforms in $L^2$

22 votes
8 answers
3k views

Simpler proofs using the axiom of choice [duplicate]

107 votes
10 answers
28k views

What is the oldest open problem in mathematics?

3 votes
1 answer
143 views

Boundedness of orbits and limit sets

4 votes
0 answers
176 views

Continuity of equivalence relations

23 votes
3 answers
9k views

Sets with positive Lebesgue measure boundary

1 vote
0 answers
299 views

Convergence in law and distribution theory

1 vote
0 answers
74 views

Is the set of functions between two arbitrarily close L^1 functions closed?

5 votes
1 answer
340 views

Euclidean norms of matrices

11 votes
2 answers
1k views

Early successes of Schwartz distribution theory

8 votes
1 answer
599 views

Etale fundamental group of the circle

11 votes
2 answers
1k views

Algebraic topology over fields other than ${\bf R}$

3 votes
0 answers
72 views

Integral representation of cochains and a theorem of Hopf

4 votes
0 answers
155 views

Extension of smooth structure on three dimensional topological manifolds

3 votes
1 answer
447 views

Projective invariants of the plane and cross ratio

7 votes
2 answers
309 views

Planar flow with bounded orbits and a single equilibrium point

17 votes
4 answers
981 views

Is $O_n({\bf Q})$ dense in $O_n({\bf R})$?

3 votes
0 answers
99 views

algebraic number with explicit base two digits

7 votes
0 answers
399 views

Bounded open sets with same boundaries

2 votes
0 answers
133 views

Homogeneous metric surfaces

4 votes
0 answers
114 views

Klein geometry associated to a degenerate conic

11 votes
2 answers
497 views

Continuous version of the fundamental theorem of invariant theory for the orthogonal group

6 votes
0 answers
213 views

Invariant theory for the orthogonal group and Clifford algebras

3 votes
0 answers
118 views

Stewart's formula in plane geometry

14 votes
1 answer
1k views

Characterizing $\mathbf{R}$ as an ordered group

1 vote
0 answers
65 views

Closure of the periodic points in the logistic family