"5차방정식과 근의 공식"의 두 판 사이의 차이

수학노트
둘러보기로 가기 검색하러 가기
15번째 줄: 15번째 줄:
 
 
 
 
  
<h5 style="line-height: 3.428em; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; color: rgb(34, 61, 103); font-family: 'malgun gothic', dotum, gulim, sans-serif; font-size: 1.166em; background-image: ; background-color: initial; background-position: 0px 100%;">Sketch of the original proof</h5>
+
<h5 style="line-height: 3.428em; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; color: rgb(34, 61, 103); font-family: 'malgun gothic', dotum, gulim, sans-serif; font-size: 1.166em; background-image: ; background-color: initial; background-position: 0px 100%;">증명의 개요</h5>
  
 
We start from the field of symmetric functions.
 
We start from the field of symmetric functions.
29번째 줄: 29번째 줄:
 
* <math>K=\mathbb{C}(x_1,\cdots,x_n)</math><br>
 
* <math>K=\mathbb{C}(x_1,\cdots,x_n)</math><br>
 
* <math>F=\mathbb{C}(s_1,\cdots,s_n)</math><br>
 
* <math>F=\mathbb{C}(s_1,\cdots,s_n)</math><br>
 +
 +
 
 +
 +
 
 +
 +
<h5 style="line-height: 2em; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">오차방정식</h5>
 +
 +
 
 +
 +
 
 +
 +
 
 +
 +
* [[갈루아 이론]]<br>
 +
* [[갈루아 이론 (피)]]<br>
  
 
 
 
 
36번째 줄: 51번째 줄:
 
<h5 style="line-height: 2em; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">solvable in radicals</h5>
 
<h5 style="line-height: 2em; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;">solvable in radicals</h5>
  
 <br>
+
 
  
 
 
 
 

2010년 1월 31일 (일) 18:53 판

이 항목의 스프링노트 원문주소

 

 

 

개요

 

 

 

증명의 개요

We start from the field of symmetric functions.

Essentially, we are studying the radical extension of that base field.

The proof is consisted of two steps.

1. radicals to express the quintic formula can be expressed in terms of roots

2. the behavior of radicals under permutations

  • \(K=\mathbb{C}(x_1,\cdots,x_n)\)
  • \(F=\mathbb{C}(s_1,\cdots,s_n)\)

 

 

오차방정식

 

 

 

 

 

solvable in radicals

 

 

 

Monodromy proof

Consider \(3w^5-25w^3+60w-z=0\).

For \(z=\pm 38\) and \(z=\pm 16\), the above equation has four distinct roots.

These are the branch points and determines the Riemann surfaces.

Then the monodromy group is acting as a permutation of sheets and not solvable.

(This is a little different from the Galois group.)

We can apply this monodromy idea to the computation of Galois groups of number fields.

 

 

regular proof

\(f(x)=2x^5-5x^4+5\) is the irreducible polynomial of degree 5 over the rationals.

It has two complex and 3 real roots.

This implies the Galois group is \(S_5\).

 

 

 

 

 

관련된 학부 과목과 미리 알고 있으면 좋은 것들

 

관련된 대학원 과목

 

 

관련된 다른 주제들

 

 

링크

 

 

관련논문