"N차원 구면"의 두 판 사이의 차이

2020년 11월 12일 (목) 08:15 판

개요

반지름 r인 n-차원 구면(n-sphere)
- (n+1)-차원 유클리드 공간에서 다음 을 만족시키는 점들의 집합 \(x_1^2+\cdots+x_{n+1}^2= r^2\)

매개화

1차원 구면 \(S^1\)

\(\begin{array}{ccc} x_1 & = & r \cos (\theta ) \\ x_2 & = & r \sin (\theta ) \end{array}\) \(0\leq \theta \leq 2\pi\)

야코비안 \(r\)

원의 매개화와 삼각함수의 탄생 참조

2차원 구면 \(S^2\)

\(\begin{array}{ccc} x_1 & = & r \cos (\theta ) \sin \left(\phi _1\right) \\ x_2 & = & r \sin (\theta ) \sin \left(\phi _1\right) \\ x_3 & = & r \cos \left(\phi _1\right) \end{array}\) 야코비안 \(r^2 \sin \left(\phi _1\right)\) \(0\leq \theta \leq 2\pi\), \(0\leq \phi_1 \leq \pi\)

3차원 구면 \(S^3\)

\(\begin{array}{ccc} x_1 & = & r \cos (\theta ) \sin \left(\phi _1\right) \sin \left(\phi _2\right) \\ x_2 & = & r \sin (\theta ) \sin \left(\phi _1\right) \sin \left(\phi _2\right) \\ x_3 & = & r \sin \left(\phi _2\right) \cos \left(\phi _1\right) \\ x_4 & = & r \cos \left(\phi _2\right) \end{array}\) 야코비안 \(r^3 \sin \left(\phi _1\right) \sin ^2\left(\phi _2\right)\) \(0\leq \theta \leq 2\pi\), \(0\leq \phi_1,\phi_2 \leq \pi\)

4차원 구면 \(S^4\)

\(\begin{array}{ccc} x_1 & = & r \cos (\theta ) \sin \left(\phi _1\right) \sin \left(\phi _2\right) \sin \left(\phi _3\right) \\ x_2 & = & r \sin (\theta ) \sin \left(\phi _1\right) \sin \left(\phi _2\right) \sin \left(\phi _3\right) \\ x_3 & = & r \sin \left(\phi _2\right) \sin \left(\phi _3\right) \cos \left(\phi _1\right) \\ x_4 & = & r \sin \left(\phi _3\right) \cos \left(\phi _2\right) \\ x_5 & = & r \cos \left(\phi _3\right) \end{array}\) 야코비안 \(r^4 \sin \left(\phi _1\right) \sin ^2\left(\phi _2\right) \sin ^3\left(\phi _3\right)\) \(0\leq \theta \leq 2\pi\), \(0\leq \phi_1,\phi_2,\phi_3 \leq \pi\)

단위구면의 부피에의 응용

n차원 구면의 매개화 다음의 점화식을 얻을 수 있다\[ \omega_{n}=\omega_{n-1}\left(\int_0^{\pi }\sin ^{n-1} \phi \, d\phi\right)=\omega_{n-1}\frac{\sqrt{\pi } \Gamma \left(\frac{n}{2}\right)}{\Gamma \left(\frac{n+1}{2}\right)}\]\[\omega_1=2\pi \]

역사

메모

야코비안 행렬 : 7차원의 경우

\[ \left( \begin{array}{cccccccc} \cos \left(\theta _1\right) & -r \sin \left(\theta _1\right) & 0 & 0 & 0 & 0 & 0 & 0 \\ \sin \left(\theta _1\right) \cos \left(\theta _2\right) & r \cos \left(\theta _1\right) \cos \left(\theta _2\right) & -r \sin \left(\theta _1\right) \sin \left(\theta _2\right) & 0 & 0 & 0 & 0 & 0 \\ \sin \left(\theta _1\right) \sin \left(\theta _2\right) \cos \left(\theta _3\right) & r \sin \left(\theta _2\right) \cos \left(\theta _1\right) \cos \left(\theta _3\right) & r \sin \left(\theta _1\right) \cos \left(\theta _2\right) \cos \left(\theta _3\right) & -r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) & 0 & 0 & 0 & 0 \\ \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \cos \left(\theta _4\right) & r \sin \left(\theta _2\right) \sin \left(\theta _3\right) \cos \left(\theta _1\right) \cos \left(\theta _4\right) & r \sin \left(\theta _1\right) \sin \left(\theta _3\right) \cos \left(\theta _2\right) \cos \left(\theta _4\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \cos \left(\theta _3\right) \cos \left(\theta _4\right) & -r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) & 0 & 0 & 0 \\ \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \cos \left(\theta _5\right) & r \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \cos \left(\theta _1\right) \cos \left(\theta _5\right) & r \sin \left(\theta _1\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \cos \left(\theta _2\right) \cos \left(\theta _5\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _4\right) \cos \left(\theta _3\right) \cos \left(\theta _5\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \cos \left(\theta _4\right) \cos \left(\theta _5\right) & -r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) & 0 & 0 \\ \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \cos \left(\theta _6\right) & r \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \cos \left(\theta _1\right) \cos \left(\theta _6\right) & r \sin \left(\theta _1\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \cos \left(\theta _2\right) \cos \left(\theta _6\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \cos \left(\theta _3\right) \cos \left(\theta _6\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _5\right) \cos \left(\theta _4\right) \cos \left(\theta _6\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \cos \left(\theta _5\right) \cos \left(\theta _6\right) & -r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) & 0 \\ \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) \cos \left(\theta _7\right) & r \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) \cos \left(\theta _1\right) \cos \left(\theta _7\right) & r \sin \left(\theta _1\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) \cos \left(\theta _2\right) \cos \left(\theta _7\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) \cos \left(\theta _3\right) \cos \left(\theta _7\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) \cos \left(\theta _4\right) \cos \left(\theta _7\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _6\right) \cos \left(\theta _5\right) \cos \left(\theta _7\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \cos \left(\theta _6\right) \cos \left(\theta _7\right) & -r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) \sin \left(\theta _7\right) \\ \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) \sin \left(\theta _7\right) & r \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) \sin \left(\theta _7\right) \cos \left(\theta _1\right) & r \sin \left(\theta _1\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) \sin \left(\theta _7\right) \cos \left(\theta _2\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) \sin \left(\theta _7\right) \cos \left(\theta _3\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) \sin \left(\theta _7\right) \cos \left(\theta _4\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _6\right) \sin \left(\theta _7\right) \cos \left(\theta _5\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \sin \left(\theta _7\right) \cos \left(\theta _6\right) & r \sin \left(\theta _1\right) \sin \left(\theta _2\right) \sin \left(\theta _3\right) \sin \left(\theta _4\right) \sin \left(\theta _5\right) \sin \left(\theta _6\right) \cos \left(\theta _7\right) \\ \end{array} \right) \]

역행렬

\[ \left( \begin{array}{cccccccc} \cos \theta _1 & \left(\sin \theta _1\right) \left(\cos \theta _2\right) & \left(\sin \theta _1\right) \left(\sin \theta _2\right) \left(\cos \theta _3\right) & \left(\sin \theta _1\right) \left(\sin \theta _2\right) \left(\sin \theta _3\right) \left(\cos \theta _4\right) & \left(\sin \theta _1\right) \left(\sin \theta _2\right) \left(\sin \theta _3\right) \left(\sin \theta _4\right) \left(\cos \theta _5\right) & \left(\sin \theta _1\right) \left(\sin \theta _2\right) \left(\sin \theta _3\right) \left(\sin \theta _4\right) \left(\sin \theta _5\right) \left(\cos \theta _6\right) & \left(\sin \theta _1\right) \left(\sin \theta _2\right) \left(\sin \theta _3\right) \left(\sin \theta _4\right) \left(\sin \theta _5\right) \left(\sin \theta _6\right) \left(\cos \theta _7\right) & \left(\sin \theta _1\right) \left(\sin \theta _2\right) \left(\sin \theta _3\right) \left(\sin \theta _4\right) \left(\sin \theta _5\right) \left(\sin \theta _6\right) \left(\sin \theta _7\right) \\ -\frac{\sin \theta _1}{r} & \frac{\left(\cos \theta _1\right) \left(\cos \theta _2\right)}{r} & \frac{\left(\sin \theta _2\right) \left(\cos \theta _1\right) \left(\cos \theta _3\right)}{r} & \frac{\left(\sin \theta _2\right) \left(\sin \theta _3\right) \left(\cos \theta _1\right) \left(\cos \theta _4\right)}{r} & \frac{\left(\sin \theta _2\right) \left(\sin \theta _3\right) \left(\sin \theta _4\right) \left(\cos \theta _1\right) \left(\cos \theta _5\right)}{r} & \frac{\left(\sin \theta _2\right) \left(\sin \theta _3\right) \left(\sin \theta _4\right) \left(\sin \theta _5\right) \left(\cos \theta _1\right) \left(\cos \theta _6\right)}{r} & \frac{\left(\sin \theta _2\right) \left(\sin \theta _3\right) \left(\sin \theta _4\right) \left(\sin \theta _5\right) \left(\sin \theta _6\right) \left(\cos \theta _1\right) \left(\cos \theta _7\right)}{r} & \frac{\left(\sin \theta _2\right) \left(\sin \theta _3\right) \left(\sin \theta _4\right) \left(\sin \theta _5\right) \left(\sin \theta _6\right) \left(\sin \theta _7\right) \left(\cos \theta _1\right)}{r} \\ 0 & -\frac{\left(\sin \theta _2\right) \left(\csc \theta _1\right)}{r} & \frac{\left(\cos \theta _2\right) \left(\cos \theta _3\right) \left(\csc \theta _1\right)}{r} & \frac{\left(\sin \theta _3\right) \left(\cos \theta _2\right) \left(\cos \theta _4\right) \left(\csc \theta _1\right)}{r} & \frac{\left(\sin \theta _3\right) \left(\sin \theta _4\right) \left(\cos \theta _2\right) \left(\cos \theta _5\right) \left(\csc \theta _1\right)}{r} & \frac{\left(\sin \theta _3\right) \left(\sin \theta _4\right) \left(\sin \theta _5\right) \left(\cos \theta _2\right) \left(\cos \theta _6\right) \left(\csc \theta _1\right)}{r} & \frac{\left(\sin \theta _3\right) \left(\sin \theta _4\right) \left(\sin \theta _5\right) \left(\sin \theta _6\right) \left(\cos \theta _2\right) \left(\cos \theta _7\right) \left(\csc \theta _1\right)}{r} & \frac{\left(\sin \theta _3\right) \left(\sin \theta _4\right) \left(\sin \theta _5\right) \left(\sin \theta _6\right) \left(\sin \theta _7\right) \left(\cos \theta _2\right) \left(\csc \theta _1\right)}{r} \\ 0 & 0 & -\frac{\left(\sin \theta _3\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right)}{r} & \frac{\left(\cos \theta _3\right) \left(\cos \theta _4\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right)}{r} & \frac{\left(\sin \theta _4\right) \left(\cos \theta _3\right) \left(\cos \theta _5\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right)}{r} & \frac{\left(\sin \theta _4\right) \left(\sin \theta _5\right) \left(\cos \theta _3\right) \left(\cos \theta _6\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right)}{r} & \frac{\left(\sin \theta _4\right) \left(\sin \theta _5\right) \left(\sin \theta _6\right) \left(\cos \theta _3\right) \left(\cos \theta _7\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right)}{r} & \frac{\left(\sin \theta _4\right) \left(\sin \theta _5\right) \left(\sin \theta _6\right) \left(\sin \theta _7\right) \left(\cos \theta _3\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right)}{r} \\ 0 & 0 & 0 & -\frac{\left(\sin \theta _4\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right)}{r} & \frac{\left(\cos \theta _4\right) \left(\cos \theta _5\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right)}{r} & \frac{\left(\sin \theta _5\right) \left(\cos \theta _4\right) \left(\cos \theta _6\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right)}{r} & \frac{\left(\sin \theta _5\right) \left(\sin \theta _6\right) \left(\cos \theta _4\right) \left(\cos \theta _7\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right)}{r} & \frac{\left(\sin \theta _5\right) \left(\sin \theta _6\right) \left(\sin \theta _7\right) \left(\cos \theta _4\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right)}{r} \\ 0 & 0 & 0 & 0 & -\frac{\left(\sin \theta _5\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right) \left(\csc \theta _4\right)}{r} & \frac{\left(\cos \theta _5\right) \left(\cos \theta _6\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right) \left(\csc \theta _4\right)}{r} & \frac{\left(\sin \theta _6\right) \left(\cos \theta _5\right) \left(\cos \theta _7\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right) \left(\csc \theta _4\right)}{r} & \frac{\left(\sin \theta _6\right) \left(\sin \theta _7\right) \left(\cos \theta _5\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right) \left(\csc \theta _4\right)}{r} \\ 0 & 0 & 0 & 0 & 0 & -\frac{\left(\sin \theta _6\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right) \left(\csc \theta _4\right) \left(\csc \theta _5\right)}{r} & \frac{\left(\cos \theta _6\right) \left(\cos \theta _7\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right) \left(\csc \theta _4\right) \left(\csc \theta _5\right)}{r} & \frac{\left(\sin \theta _7\right) \left(\cos \theta _6\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right) \left(\csc \theta _4\right) \left(\csc \theta _5\right)}{r} \\ 0 & 0 & 0 & 0 & 0 & 0 & -\frac{\left(\sin \theta _7\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right) \left(\csc \theta _4\right) \left(\csc \theta _5\right) \left(\csc \theta _6\right)}{r} & \frac{\left(\cos \theta _7\right) \left(\csc \theta _1\right) \left(\csc \theta _2\right) \left(\csc \theta _3\right) \left(\csc \theta _4\right) \left(\csc \theta _5\right) \left(\csc \theta _6\right)}{r} \\ \end{array} \right)\]

매스매티카 파일 및 계산 리소스

https://docs.google.com/file/d/0B8XXo8Tve1cxakJjVmNBWHh2VTg/edit

@@ 1번째 줄: / 1번째 줄: @@
 ==개요==
-*  반지름 r인 n-차원 구면(n-sphere)<br>
+*  반지름 r인 n-차원 구면(n-sphere)
 ** (n+1)-차원 유클리드 공간에서 다음 을 만족시키는 점들의 집합 <math>x_1^2+\cdots+x_{n+1}^2= r^2</math>
@@ 35번째 줄: / 35번째 줄: @@
 ===단위구면의 부피에의 응용===
-* [[n차원 구면의 매개화|n차원 구면의 매개화]]<br> 다음의 점화식을 얻을 수 있다:<math> \omega_{n}=\omega_{n-1}\left(\int_0^{\pi }\sin ^{n-1} \phi \, d\phi\right)=\omega_{n-1}\frac{\sqrt{\pi } \Gamma \left(\frac{n}{2}\right)}{\Gamma \left(\frac{n+1}{2}\right)}</math>:<math>\omega_1=2\pi </math><br>
+* [[n차원 구면의 매개화|n차원 구면의 매개화]] 다음의 점화식을 얻을 수 있다:<math> \omega_{n}=\omega_{n-1}\left(\int_0^{\pi }\sin ^{n-1} \phi \, d\phi\right)=\omega_{n-1}\frac{\sqrt{\pi } \Gamma \left(\frac{n}{2}\right)}{\Gamma \left(\frac{n+1}{2}\right)}</math>:<math>\omega_1=2\pi </math>
@@ 52번째 줄: / 52번째 줄: @@
 ==메모==
 * 야코비안 행렬 : 7차원의 경우
-$$
+:<math>
 \left(
 \begin{array}{cccccccc}
@@ 65번째 줄: / 65번째 줄: @@
 \end{array}
 \right)
-$$
+</math>
 * 역행렬
-$$
+:<math>
 \left(
 \begin{array}{cccccccc}
@@ 81번째 줄: / 81번째 줄: @@
 & 0 & 0 & 0 & 0 & 0 & -\frac{\left(\sin  \theta _7\right) \left(\csc  \theta _1\right) \left(\csc  \theta _2\right) \left(\csc  \theta _3\right) \left(\csc  \theta _4\right) \left(\csc  \theta _5\right) \left(\csc  \theta _6\right)}{r} & \frac{\left(\cos  \theta _7\right) \left(\csc  \theta _1\right) \left(\csc  \theta _2\right) \left(\csc  \theta _3\right) \left(\csc  \theta _4\right) \left(\csc  \theta _5\right) \left(\csc  \theta _6\right)}{r} \\
 \end{array}
-\right)$$
+\right)</math>