User Jim - Mathematics Stack Exchange

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	8,795 reputation	bio	website		visits	member for	5 months
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31

87

votes

2

answers

3

kviews

Can we ascertain that there exists an epimorphism $G\rightarrow H$?

may 4 at 1:53 user32240 5,164

6

21

votes

0

answers

394

views

A short proof for $\dim(R[T])=\dim(R)+1$?

commutative-algebra ring-theory dimension-theory

apr 23 at 22:13 Martin Brandenburg 24.6k

3

18

votes

1

answer

354

views

Are finitely generated projective modules free over the total ring of fractions?

abstract-algebra commutative-algebra

feb 21 at 11:42 YACP 9,938

8

12

votes

4

answers

257

views

Irreducibility of Polynomials in $k[x,y]$

algebraic-geometry commutative-algebra

feb 14 at 17:19 Hurkyl 22.2k

2

12

votes

1

answer

309

views

When is the derived category abelian?

category-theory homological-algebra abelian-categories triangulated-categories

sep 6 at 17:06 t.b. 43.5k

2

12

votes

3

answers

409

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Localization at a prime ideal is a reduced ring

abstract-algebra algebraic-geometry commutative-algebra

jul 22 '12 at 13:05 Norbert 21.3k

5

10

votes

2

answers

94

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Irrational numbers, decimal representation

number-theory irrational-numbers transcendental-numbers decimal-expansion transcendence-theory

may 2 at 7:56 Pieter Cuijpers 31

2

10

votes

2

answers

89

views

What is a primary decomposition of the ideal $I = \langle xy, x - yz \rangle$?

commutative-algebra ring-theory

may 8 at 7:43 Fredrik Meyer 5,395

2

8

votes

2

answers

97

views

Variety of Nilpotent Matrices

matrices algebraic-geometry

may 29 at 21:25 Matt E 60.3k

3

7

votes

1

answer

102

views

Finite factor ring

commutative-algebra ring-theory finite-fields

mar 26 at 18:50 azimut 5,783

1

7

votes

1

answer

81

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Can we really understand $R$ by studying $R$-modules? [duplicate]

abstract-algebra reference-request commutative-algebra category-theory modules

mar 28 at 15:22 Community♦ 1

3

6

votes

1

answer

110

views

How to compute Hom in derived category?

algebraic-geometry cohomology derived-functors

mar 3 at 20:23 Piotr Pstragowski 1,279

1

6

votes

2

answers

136

views

Restriction of scalars and tensor product

commutative-algebra modules tensor-products

feb 1 at 5:34 Barbara Osofsky 925

1

6

votes

1

answer

40

views

Showing the $V(\mathfrak{a})$ give us a topology on Proj$S$

algebraic-geometry

apr 26 at 8:37 Martin Brandenburg 24.6k

4

6

votes

0

answers

395

views

Partial Solution to the Twin Primes Conjecture — What does it imply? [closed]

prime-numbers prime-twins

may 16 at 9:09 Jeffery Ritaz 1

1

5

votes

1

answer

98

views

Nicolas Boubarki, Algebra I, Chapter 1, § 2, Ex. 12

abstract-algebra

apr 15 at 20:58 Boris Novikov 6,029

2

5

votes

0

answers

46

views

Jordan canonical form of commuting matrices [duplicate]

linear-algebra matrices

apr 4 at 17:51 Weltschmerz 2,947

2

5

votes

1

answer

49

views

If $M \simeq N$ in ${\tt stmod}(G)$ will $M \oplus \text{(proj)} \simeq N \oplus \text{(proj)}$ in ${\tt mod}(G)$?

representation-theory modules homological-algebra

jun 4 at 11:00 Martin 4,487

1

5

votes

1

answer

64

views

Is this an affine surface?

homework algebraic-geometry

2d ago Martin Brandenburg 24.6k

1

5

votes

1

answer

130

views

Distance between a point and closed set in finite dimensional space

functional-analysis normed-spaces

apr 8 at 20:32 Plop 131

1

5

votes

1

answer

103

views

Noetherian rings and prime ideals

commutative-algebra

mar 19 at 17:29 YACP 9,938

1

5

votes

3

answers

91

views

Cylinder object in the model category of chain complexes

algebraic-topology category-theory homological-algebra homotopy-theory model-categories

jun 5 at 7:44 Avitus 1,041

1

4

votes

0

answers

40

views

Tangent bundle of an algebraic group

algebraic-groups

apr 4 at 0:56 Sanchez 4,450

1

4

votes

2

answers

132

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Epic maps in the category of commutative rings with identity.

reference-request commutative-algebra ring-theory

feb 2 at 21:10 Barbara Osofsky 925

1

4

votes

1

answer

157

views

Defining multiplication on a Koszul complex

abstract-algebra commutative-algebra algebraic-topology ring-theory homological-algebra

jun 4 at 10:42 Avitus 1,041

3

4

votes

2

answers

115

views

Representations of Direct Sum of Lie Algebras

vector-spaces representation-theory lie-groups lie-algebras tensor-products

feb 24 at 2:51 Eric O. Korman 7,945

2

4

votes

1

answer

68

views

Characterization of faithfully flat homomorphisms

commutative-algebra

apr 6 at 16:24 Martin Brandenburg 24.6k

2

3

votes

0

answers

28

views

Reduction map on $SL(2,\mathbb{Z}/p^{n}\mathbb{Z})$

abstract-algebra

apr 9 at 0:41 jennifer 2,764

1

3

votes

0

answers

51

views

Tensor products over field do not commute with inverse limits?

linear-algebra examples-counterexamples tensor-products

may 10 at 11:24 Boris Datsik 121

1

3

votes

0

answers

54

views

The enveloping algebra of a finite dimensional Lie algebra has no zero divisor

lie-algebras

mar 4 at 15:55 rschwieb 22.6k

Jim

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