User Bach

5

votes

2

answers

92

views

Find the maximal value for $ \left| \int_{0}^{1}(f(x))^2-f(x)dx \right| .$

real-analysis optimization

Sep 23 '18 at 10:30 Gabriel Romon 30.1k

3

votes

1

answer

145

views

Show that finitely generated cone in Hilbert space is closed.

hilbert-spaces finitely-generated convex-cone

Sep 17 '18 at 15:45 Matematleta 24.4k

6

votes

1

answer

405

views

Groups of order $360$ have a subgroup of order $10$

abstract-algebra group-theory finite-groups

Jan 11 '19 at 12:37 the_fox 5,482

1

vote

1

answer

728

views

A finite group with exactly $2$ conjugacy classes isomorphic to $\mathbb{Z}_2$

group-theory group-isomorphism group-homomorphism

Jul 23 '19 at 15:03 Bach 4,745

2

votes

1

answer

150

views

Counting number of p-Sylow subgroups in $A_n$

symmetric-groups permutation-cycles

Sep 2 '18 at 0:02 A. Pongrácz 6,832

1

vote

2

answers

2k

views

Centre of the special linear group $SL_2(\mathbb R)$ or $SL(2,\mathbb R)$

linear-algebra abstract-algebra matrices group-theory linear-groups

Sep 5 '18 at 2:06 Community♦ 1

5

votes

1

answer

408

views

What is a Coxeter Group?

group-theory reflection coxeter-groups

Jan 10 '20 at 9:36 Babelfish 1,651

2

votes

1

answer

540

views

$l^\infty$ is not separable

real-analysis

Aug 27 '18 at 6:24 Berci 81.3k

3

votes

2

answers

202

views

Find all characteristic subgroups of the Dihedral group $D_{12}$.

abstract-algebra group-theory dihedral-groups characteristic-subgroups

Aug 21 '18 at 20:54 Chris Custer 40.1k

11

votes

4

answers

1k

views

Topologically, is there a definition of differentiability that is dependent on the underlying topology, similar to continuity?

real-analysis general-topology derivatives continuity differential-topology

Aug 17 '18 at 7:49 mathcounterexamples.net 53.4k

2

votes

1

answer

470

views

Hunting for a basis: Rational Canonical Form

linear-algebra matrices

Oct 29 at 14:46 Carlo 4,144

0

votes

2

answers

559

views

Conformal map of the upper half plane minus a disc onto an annulus? [closed]

complex-analysis holomorphic-functions

Oct 4 '18 at 1:13 Maxim 9,499

14

votes

2

answers

3k

views

A list of proofs of Fourier inversion formula

soft-question fourier-analysis fourier-transform

Aug 19 '18 at 15:30 Disintegrating By Parts 72.8k

3

votes

1

answer

131

views

Let G be $\mathbb Z_p\times\dots\times \mathbb Z_p$ . Find A(G).

finite-groups p-groups pro-p-groups

Jul 29 '18 at 16:05 Henrique Augusto Souza 2,461

3

votes

3

answers

158

views

How to understand the notation $ \frac{\partial f}{\partial \overline{z}} $

complex-analysis analysis

Jul 19 '18 at 14:02 Bob 3,758

5

votes

1

answer

651

views

How to prove that all primes of the form $4k+1$ can be represented by the sum of two squares in only one way regardless of the order?

number-theory prime-numbers sums-of-squares

Jan 17 '19 at 6:38 Alexander Gruber♦ 25.8k

5

votes

0

answers

200

views

Fourier series: $\hat f(n)=O(1/n)$ and $f$ continuous implies uniform convergence?

fourier-analysis fourier-series uniform-convergence tauberian-theory

Jul 16 '18 at 20:34 fonini 2,365

0

votes

3

answers

59

views

The Laurent series for $ f(z)=\frac{1}{z-5} $ centered at $ z=2 $

complex-analysis

Jul 10 '18 at 7:35 Fred 71.3k

5

votes

1

answer

900

views

Burnside's transfer theorem in group theory

abstract-algebra group-theory finite-groups sylow-theory

Nov 12 '19 at 7:56 YCor 14.4k

1

vote

1

answer

31

views

Fourier coefficients of measurable homomorphism from $\mathbb{T}$ to $T^*$

fourier-analysis harmonic-analysis

Jun 30 '18 at 15:36 David C. Ullrich 77.9k

2

votes

2

answers

578

views

Proving every prime ideal is maximal in a finite dimensional ring over a field. [duplicate]

abstract-algebra ring-theory

Jun 30 '18 at 16:05 Jyrki Lahtonen 119k

1

vote

1

answer

546

views

The tangential gradient of a function $f$ defined on a manifold

differential-geometry riemannian-geometry mean-curvature-flows

Jul 19 '19 at 22:39 George 2,745

5

votes

1

answer

2k

views

Let $a$ be a p-cycle in $S_p$, and let $b$ be a transposition in $S_p$. Show $S_p$ is generated by $a$ and $b$.

abstract-algebra group-theory permutations galois-theory symmetric-groups

May 23 '18 at 9:48 Derek Holt 69.1k

1

vote

2

answers

2k

views

proof that special orthogonal group SO(2) is abelian group

abstract-algebra group-theory abelian-groups

May 12 '18 at 12:24 Dan Fox 2,216

0

votes

1

answer

494

views

Example of non-Noetherian ring

commutative-algebra noetherian

May 3 '18 at 20:19 egreg 215k

3

votes

1

answer

1k

views

an intuitive example of convergence in distribution does not imply convergence in probability

probability-theory probability-distributions probability-limit-theorems

Dec 17 at 5:37 RRL 76.6k

2

votes

3

answers

150

views

The number of elements $ \alpha $ we can adjoin to a finite field $ F $ to obtain an extension field.

abstract-algebra field-theory finite-fields

May 1 '18 at 14:24 Bach 4,745

9

votes

3

answers

534

views

Problem in the “proof” of Eisenstein's criterion on irreducibility.

abstract-algebra ring-theory irreducible-polynomials

Aug 30 at 2:44 TAO CHUAI 1

5

votes

1

answer

174

views

Does exist any integer $n\geq 1$ satisfying $\varphi(12n)=\varphi(6n+5)$, where $\varphi(m)$ denotes the Euler's totient function?

elementary-number-theory totient-function

Apr 30 '18 at 20:40 Community♦ 1

3

votes

3

answers

323

views

Does there exist a formula for product of the primitive $ n $th roots of unity.

abstract-algebra number-theory cyclotomic-polynomials

Nov 4 '18 at 22:49 draks ... 17.6k

Stack Exchange Network

current community

your communities

more stack exchange communities

Next privilege

Next badge

1,699 Bookmarks

Find the maximal value for $ \left| \int_{0}^{1}(f(x))^2-f(x)dx \right| .$

Show that finitely generated cone in Hilbert space is closed.

Groups of order $360$ have a subgroup of order $10$

A finite group with exactly $2$ conjugacy classes isomorphic to $\mathbb{Z}_2$

Counting number of p-Sylow subgroups in $A_n$

Centre of the special linear group $SL_2(\mathbb R)$ or $SL(2,\mathbb R)$

What is a Coxeter Group?

$l^\infty$ is not separable

Find all characteristic subgroups of the Dihedral group $D_{12}$.

Topologically, is there a definition of differentiability that is dependent on the underlying topology, similar to continuity?

Hunting for a basis: Rational Canonical Form

Conformal map of the upper half plane minus a disc onto an annulus? [closed]

A list of proofs of Fourier inversion formula

Let G be $\mathbb Z_p\times\dots\times \mathbb Z_p$ . Find A(G).

How to understand the notation $ \frac{\partial f}{\partial \overline{z}} $

How to prove that all primes of the form $4k+1$ can be represented by the sum of two squares in only one way regardless of the order?

Fourier series: $\hat f(n)=O(1/n)$ and $f$ continuous implies uniform convergence?

The Laurent series for $ f(z)=\frac{1}{z-5} $ centered at $ z=2 $

Burnside's transfer theorem in group theory

Fourier coefficients of measurable homomorphism from $\mathbb{T}$ to $T^*$

Proving every prime ideal is maximal in a finite dimensional ring over a field. [duplicate]

The tangential gradient of a function $f$ defined on a manifold

Let $a$ be a p-cycle in $S_p$, and let $b$ be a transposition in $S_p$. Show $S_p$ is generated by $a$ and $b$.

proof that special orthogonal group SO(2) is abelian group

Example of non-Noetherian ring

an intuitive example of convergence in distribution does not imply convergence in probability

The number of elements $ \alpha $ we can adjoin to a finite field $ F $ to obtain an extension field.

Problem in the “proof” of Eisenstein's criterion on irreducibility.

Does exist any integer $n\geq 1$ satisfying $\varphi(12n)=\varphi(6n+5)$, where $\varphi(m)$ denotes the Euler's totient function?

Does there exist a formula for product of the primitive $ n $th roots of unity.