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Fomalhaut
  • Member for 8 years, 8 months
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10 votes
1 answer
405 views

What statements are equivalent to the Axiom of Determinacy?

8 votes
3 answers
510 views

Can you give me a concrete example of a sphere being defined without reference to an ambient space?

5 votes
1 answer
751 views

Going from Metric to Distance Function in the Poincaré Half Plane

5 votes
3 answers
916 views

Geometrically interpreting $\Im ({z}/{(z + 1)^2} )$

5 votes
1 answer
293 views

Is there a generalization for "planar graph" for any dimension?

5 votes
1 answer
119 views

How do we formalize the derivation of the ideal gas law from Boyle's Law, Charles's Law, and Avogadro's Law?

4 votes
1 answer
193 views

What is a gyrational square in this context?

4 votes
2 answers
203 views

Derive ideal form of Bézout's Identity: $a\Bbb Z + b\Bbb Z = \gcd(a,b)\Bbb Z$

4 votes
1 answer
454 views

Direct sums of left ideals and orthogonal idempotents

4 votes
1 answer
2k views

Proving the inclusion-exclusion principle for measures

4 votes
2 answers
105 views

Is the normality of a subgroup dependent on which group is its parent?

4 votes
2 answers
255 views

Considering a non-standard set theory

4 votes
4 answers
323 views

Proving that the limit of an abstract function with certain properties is zero.

3 votes
1 answer
2k views

Statistical Testing of a Biased Coin

3 votes
2 answers
7k views

How do I find the conjugacy classes of $A_4$?

3 votes
1 answer
503 views

How can a spectrum object be constructed?

3 votes
3 answers
904 views

Image of a complex function contained in a line. Prove that the function is constant.

3 votes
7 answers
3k views

Why can't I prove summation identities without guessing?

3 votes
0 answers
150 views

How do I turn a group presentation into a multiplication table?

2 votes
1 answer
365 views

How do I complete the steps of finding the Jordan of this $5\times 5$ matrix (with Octave)?

2 votes
2 answers
164 views

How do I find the generator $(g)$ that generates $(29, \sqrt{-5} ± 13)$

2 votes
3 answers
120 views

What do group theorists mean when they say that $g \mapsto gH$ is undefined when $H$ is non-normal? [closed]

2 votes
2 answers
81 views

How do I express the main idea of this proof in the language of group theory?

2 votes
0 answers
255 views

Why were evil numbers named "evil"?

2 votes
1 answer
127 views

Measure theory and the extrema four inequality

2 votes
1 answer
285 views

Cartesian product of fields is semisimple iff the index set is finite

2 votes
2 answers
282 views

Pythagorean Theorem in an Inner Product Space

2 votes
2 answers
327 views

Variants of Fatou's Lemma

2 votes
2 answers
101 views

Different sums that preserve divisibility

2 votes
4 answers
551 views

Extended complex numbers: what kind of algebra is it?