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Conifold
  • Member for 9 years, 6 months
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18 votes
1 answer
731 views

Are there spaces that 'look the same' at every point, but are not homogeneous?

18 votes
2 answers
1k views

Are there non-standard counterexamples to the Fermat Last Theorem?

14 votes
2 answers
1k views

Why do we know that Gödel sentences are true in the standard model of set theory, but do not know if the continuum hypothesis is?

13 votes
2 answers
508 views

Is Archimedes's method for computing volumes equivalent to Cavalieri's?

12 votes
1 answer
2k views

What is the reflection across a parabola?

11 votes
1 answer
256 views

Is there a clever way to find a smaller number that produces the Euclidean algorithm of given length?

10 votes
3 answers
63k views

Are triangles the strongest shape?

9 votes
2 answers
531 views

How many different products can be formed by multiplying $n$ numbers at most once?

8 votes
1 answer
952 views

Why is the powerset axiom more acceptable than the axiom of choice?

7 votes
1 answer
700 views

Partial order on cardinalities without the axiom of choice

7 votes
1 answer
4k views

Functions with every point being a Lebesgue point

7 votes
2 answers
2k views

What is the multiplicative order of a product of two integers $\mod n$?

6 votes
1 answer
809 views

Circle inversion and the Pappus chain paradox

6 votes
1 answer
452 views

Is there a theory of integration in elementary terms for definite integrals?

6 votes
1 answer
464 views

How do inconsistent arithmetics get around Gödel incompleteness?

6 votes
1 answer
606 views

Are all rationally parametrized plane curves algebraic? How does one find their degree?

5 votes
2 answers
448 views

Can one prove existence of incommensurables without the Pythagorean theorem?

5 votes
1 answer
599 views

Finding covering system of congruences with prescribed moduli

4 votes
0 answers
160 views

Can existence of aleph one be proved without the power set axiom? [duplicate]

4 votes
1 answer
764 views

Can hyperreal numbers be studied 'naively', like surreal numbers?

4 votes
1 answer
2k views

What is the dual space in the strong operator topology?

4 votes
1 answer
112 views

How many integer matrices have spectral radius bounded by a constant?

4 votes
2 answers
150 views

Example of a sequence that is Cauchy in a stronger norm and convergent in a weaker norm, but not convergent in the stronger norm?

3 votes
1 answer
344 views

Banach valued sequence spaces $\ell^p(X)$

3 votes
0 answers
100 views

Is there an intuitive reason why hippopede, the intersection curve of a sphere and a cylinder, is traced by composing two rotational motions?

2 votes
1 answer
462 views

Are order isomorphic real closed fields isomorphic?

0 votes
1 answer
126 views

Is there a formalisation of set theory where unions can be taken over some classes that are not a priori known to be sets?

0 votes
1 answer
324 views

Non-convex functions and their supporting hyperplanes