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Makoto Kato

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Top Questions
102 votes

Classification of prime ideals of $\mathbb{Z}[X]$

abstract-algebra commutative-algebra ideals prime-ideals asked Jul 24 '12 at 9:38
math.stackexchange.com

66 votes

Is memory unimportant in doing mathematics?

soft-question learning asked Nov 17 '12 at 1:44
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47 votes

Is an automorphism of the field of real numbers the identity map?

abstract-algebra field-theory real-numbers asked Jul 22 '13 at 12:00
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44 votes

Are the exercises necessary to understand the subject of a mathematical textbook?

soft-question learning asked Jun 28 '12 at 2:29
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33 votes

Unramification of a prime ideal in an order of a finite Galois extension of an algebraic number field

algebraic-number-theory asked Aug 17 '12 at 6:22
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33 votes

Do native speakers distinguish well the pronunciations of “L” and “R”?

pronunciation phonology asked Oct 12 '15 at 0:50
ell.stackexchange.com

29 votes

Mnemonic for the fact that a right(left) adjoint functor preserves limits(colimits)

category-theory adjoint-functors asked Jan 5 '13 at 15:55
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26 votes

“No more Hiroshima” or “No more Hiroshimas”

grammatical-number proper-nouns negative asked Jan 14 '15 at 10:52
ell.stackexchange.com

24 votes

A natural proof of the Cauchy-Schwarz inequality

functional-analysis inequality asked Jul 5 '13 at 5:31
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24 votes

Differentiable manifolds as locally ringed spaces

differential-geometry sheaf-theory asked Oct 30 '12 at 21:16
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Top Answers
55
Is an automorphism of the field of real numbers the identity map?
math.stackexchange.com

48
Abelian categories and axiom (AB5)
math.stackexchange.com

42
Is there a purely algebraic proof of the Fundamental Theorem of Algebra?
math.stackexchange.com

27
Constructing a Galois extension field with Galois group $S_n$
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26
Verifying that the ideal $(x^3-y^2)$ is prime
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22
Prove that $\mathbb{R^*}$, the set of all real numbers except $0$, is not a cyclic group
math.stackexchange.com

21
nontrivial theorems with trivial proofs
mathoverflow.net

19
Spivak's proof of Inverse Function Theorem
math.stackexchange.com

18
How can I prove formally that the projective plane is a Hausdorff space?
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18
Why a polynomial is solvable by radicals iff its Galois group is solvable, when $char(F)=0$?
math.stackexchange.com

17
Showing a homomorphism of a field algebraic over $\mathbb{Q}$ to itself is an isomorphism.
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15
Find all subgroups of $\mathbb{Z}\times\mathbb{Z}$.
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14
If $K$ is an extension field of $\mathbb{Q}$ such that $[K:\mathbb{Q}]=2$, prove that $K=\mathbb{Q}(\sqrt{d})$ for some square free integer $d$
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14
Compositum of abelian Galois extensions is also?
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14
Find the number of non-zero squares in the field $Zp$
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13
An element of a group $G$ is not conjugate to its inverse if $\lvert G\rvert$ is odd
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13
Theorems with an extraordinary exception or a small number of sporadic exceptions
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13
Prove $\sin x$ is uniformly continuous on $\mathbb R$
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12
Why are topological spaces interesting to study?
math.stackexchange.com

12
Showing that a Sylow subgroup of a group of order $p^{2}q$ is normal.
math.stackexchange.com

12
Easy way to show that $\mathbb{Z}[\sqrt[3]{2}]$ is the ring of integers of $\mathbb{Q}[\sqrt[3]{2}]$
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12
how to show that power series is analytic inside the radius of convergence?
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11
Sheafification of a presheaf through the etale space
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11
Finitely generated modules in exact sequence
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11
Interpreting the Cayley-Hamilton theorem
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11
Example of nonabelian group with all proper subgroups normal
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11
Morphism of Affine Algebraic Variety
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10
Discriminant of number field
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10
Prerequisite reading for Weil's Basic Number Theory
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10
Why is the tensor product important when we already have direct and semidirect products?
math.stackexchange.com

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