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Edward Evans's user avatar
Edward Evans's user avatar
Edward Evans's user avatar
Edward Evans
  • Member for 8 years, 3 months
  • Last seen more than 1 year ago
  • Heidelberg, Deutschland
18 votes
2 answers
2k views

Why does "solvability" for groups suggest something about the solution of polynomials?

13 votes
4 answers
674 views

When $\lfloor{ab}\rfloor = \lfloor{a}\rfloor\lfloor{b}\rfloor$

8 votes
4 answers
2k views

How can I show that the polynomial $p = x^5 - x^3 - 2x^2 - 2x - 1$ is irreducible over $\Bbb Q$?

7 votes
2 answers
1k views

Quotient of a quotient ring

6 votes
1 answer
457 views

Sanity check regarding Galois group of $X^8 - 3$

6 votes
1 answer
1k views

If the norm of an ideal is prime then the ideal is prime

6 votes
3 answers
697 views

Prove that all roots of $z\tan z = k$ lie in $\Bbb R$, where $k$ is a positive, non-zero real number.

6 votes
1 answer
5k views

How can I prove that the mean of squared data points is greater than the square of the mean of the data points?

5 votes
0 answers
251 views

How to determine the Galois Group of a polynomial with "ugly" roots? [duplicate]

4 votes
1 answer
274 views

Identifying isomorphic groups via their presentations

4 votes
3 answers
563 views

Uniqueness of $k$th root mod $m$ if $(k, \phi(m)) = 1$.

4 votes
1 answer
102 views

Find the degree of the extension $\Bbb R(\theta)/\Bbb R$

4 votes
1 answer
172 views

Is $R[r]$ equal to $R$ itself? And some consequences

4 votes
1 answer
1k views

Galois group of $P(X) = X^5 -7$

4 votes
3 answers
223 views

Does this constitute a valid proof that $\frac{x^2}{1+x^4} \leq \frac{1}{2}$?

4 votes
0 answers
157 views

Showing a sequence is Cauchy; loss of generality?

4 votes
0 answers
87 views

Relating the order of the class of an ideal in $\operatorname{Cl}_K$ to the class number of a finite extension $L$

3 votes
3 answers
334 views

How can I prove that the cyclotomic integers $\frac{\zeta_p^r - 1}{\zeta_p^s - 1}$, with $\ p\nmid rs$, are units?

3 votes
0 answers
74 views

Lemma on induced characters in the representation theory of finite groups

3 votes
1 answer
89 views

Equality of fields being deduced from isomorphism of Galois groups

3 votes
1 answer
188 views

Step in proof of Hasse-Arf theorem on ramification groups

3 votes
1 answer
279 views

If one root is in then all roots are in [duplicate]

3 votes
1 answer
290 views

Confusion about ideal class group computation

3 votes
1 answer
445 views

Ramification of primes in the ring of integers of a number field

2 votes
1 answer
51 views

Does the same construction that yields $K$-vector spaces when $K$ is a field yield free $K$-modules when $K$ is a ring?

2 votes
3 answers
238 views

Proof verification: product and sum of two natural numbers are consecutive natural numbers.

2 votes
1 answer
97 views

Confusion about Sylow Subgroups

2 votes
1 answer
191 views

p-Sylow Subgroups for group of order $\lvert G\rvert = kp$

2 votes
1 answer
1k views

Prove that $C_K(H) = \ker \varphi$

2 votes
3 answers
75 views

On factorisation into prime ideals in a Dedekind domain