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Saúl RM

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Top Questions
40 votes

Can the nth projective space be covered by n charts?

reference-request at.algebraic-topology gn.general-topology gt.geometric-topology differential-topology asked Nov 26, 2021 at 1:57
mathoverflow.net

25 votes

Is there an open subset $A$ of $[0,1]^2$ with measure $>\frac{1}{100}$ that satisfies this property?

measure-theory recreational-mathematics asked May 13, 2022 at 23:46
mathoverflow.net

22 votes

Can we make distances in a finite subset of a manifold whatever we want?

dg.differential-geometry mg.metric-geometry riemannian-geometry geodesics asked Mar 10, 2022 at 17:11
mathoverflow.net

18 votes

Is there a function whose graph intersects every tangent line at exactly 2 points?

real-analysis functions derivatives continuity tangent-line asked Apr 1, 2022 at 23:18
math.stackexchange.com

15 votes

Is there an open subset $A$ of $[0,1]^2$ with measure $>\frac{1}{100}$ that satisfies this property?

measure-theory multivariable-calculus geometric-measure-theory asked May 8, 2022 at 0:12
math.stackexchange.com

12 votes

Are there $n$ points dividing a compact Riemannian manifold into equal regions?

riemannian-geometry asked Dec 31, 2022 at 17:27
mathoverflow.net

9 votes

Is there any noncompact manifold with the fixed point property?

manifolds differential-topology smooth-manifolds fixed-point-theorems fixed-points asked Dec 2, 2021 at 2:07
math.stackexchange.com

8 votes

If a compact set is not convex, some ball is tangent to it at several points.

general-topology geometry euclidean-geometry geometric-topology convex-geometry asked Dec 29, 2021 at 12:02
math.stackexchange.com

8 votes

Are jumps in the growth function of an infinite group increasing?

group-theory geometric-group-theory cayley-graphs subgroup-growth asked Feb 16, 2022 at 16:38
math.stackexchange.com

7 votes

Is the union of a compact and the relatively compact components of its complementary in a manifold compact?

dg.differential-geometry gn.general-topology differential-topology compactness asked Dec 5, 2021 at 10:09
mathoverflow.net

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Top Answers
58
How many square roots can a non-identity element in a group have?
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34
Can an odd number of marbles jump to infinity?
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33
What is the smallest set of real continuous functions generating all rational numbers by iteration?
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22
The $9$th tetration of $-\sqrt2$
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21
A property of even continuous functions on the sphere
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17
Is the topology generated by this weaker notion of a metric necessarily metrisable?
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17
A gerrymandering problem - can you always turn a tie into a landslide victory?
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16
Is there an analytic non-linear function that maps rational numbers to rational numbers and it maps irrational numbers to irrational numbers?
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14
Unlinked interlocking planar polygons
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13
Can a smooth manifold be realised as the image of a smooth function?
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10
Relationship between doubling constant of a metric space and of a metric measure space
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9
Why is this space contractible?
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9
What is the minimum-curvature curve interpolating a given set of points in the plane?
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9
If an initial value problem has a solution on $[0,a)$ for all $a>0$, will it have a solution on the whole $[0,\infty)$?
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9
Existence of an open convex set
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9
Boundaries of subsets of simply-connected domains
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9
Is every rational sequence topology homeomorphic?
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9
If $\mathcal{H}^{n-1}(E)=0$ then $\mathbb{R}^n\setminus E$ is connected
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7
Does the homeomorphism have a non-negative or non-positive determinant?
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7
Do non-zero derivatives imply tangent lines (and vice versa)?
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7
Convergence of a sequence
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7
Inspired by a card game: finding a path through $[\mathbb{N}]^n$
mathoverflow.net

6
Boundedness of orbits and limit sets
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6
What is the smallest size of a shape in which all fixed $n$-polyominos can fit?
mathoverflow.net

6
Do these properties characterize Hilbert spaces?
mathoverflow.net

6
How many pairwise non-homeomorphic non-empty closed subsets of the Cantor set are there?
mathoverflow.net

5
For a point K inside a triangle show an equality
math.stackexchange.com

5
Does $C[0, 1]$ admit a covering by sets of arbitrarily small eccentricity?
mathoverflow.net

5
Center of convex figure
mathoverflow.net

5
Does the surface area of the unit Lp ball go to zero for all $p < \infty$?
mathoverflow.net

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