{"id":10300,"date":"2025-05-30T15:44:12","date_gmt":"2025-05-30T06:44:12","guid":{"rendered":"https:\/\/home.hirosaki-u.ac.jp\/relativity\/?page_id=10300"},"modified":"2025-06-03T12:20:27","modified_gmt":"2025-06-03T03:20:27","slug":"3%e6%ac%a1%e5%85%83%e3%81%ae%e3%83%a9%e3%83%97%e3%83%a9%e3%82%b7%e3%82%a2%e3%83%b3%e3%82%92%e6%a5%b5%e5%ba%a7%e6%a8%99%e3%81%a7%e8%a1%a8%e3%81%99","status":"publish","type":"page","link":"https:\/\/home.hirosaki-u.ac.jp\/relativity\/%e7%90%86%e5%b7%a5%e7%b3%bb%e3%81%ae%e6%95%b0%e5%ad%a6c\/%e5%81%8f%e5%be%ae%e5%88%86%ef%bc%9a%e5%a4%9a%e5%a4%89%e6%95%b0%e9%96%a2%e6%95%b0%e3%81%ae%e5%be%ae%e5%88%86\/%e5%90%88%e6%88%90%e9%96%a2%e6%95%b0%e3%81%ae%e5%81%8f%e5%be%ae%e5%88%86%e6%b3%95\/3%e6%ac%a1%e5%85%83%e3%81%ae%e3%83%a9%e3%83%97%e3%83%a9%e3%82%b7%e3%82%a2%e3%83%b3%e3%82%92%e6%a5%b5%e5%ba%a7%e6%a8%99%e3%81%a7%e8%a1%a8%e3%81%99\/","title":{"rendered":"3\u6b21\u5143\u306e\u30e9\u30d7\u30e9\u30b7\u30a2\u30f3\u3092\u6975\u5ea7\u6a19\u3067\u8868\u3059"},"content":{"rendered":"<p>\u5408\u6210\u95a2\u6570\u306e\u504f\u5fae\u5206\u306e\u5fdc\u7528\u3068\u3057\u3066\uff0c\uff08\u30c7\u30ab\u30eb\u30c8\u5ea7\u6a19\u3067\u5b9a\u7fa9\u3055\u308c\u305f\uff093\u6b21\u5143\u306e\u30e9\u30d7\u30e9\u30b7\u30a2\u30f3 $\\nabla^2 = \\dfrac{\\partial^2}{\\partial x^2} + \\dfrac{\\partial^2}{\\partial y^2}+ \\dfrac{\\partial^2}{\\partial z^2}$ \u3092\u6975\u5ea7\u6a19 $r, \\theta, \\phi$ \u3092\u4f7f\u3063\u3066\u8868\u3057\u3066\u307f\u308b\u3002\u7df4\u7fd2\u554f\u984c\u306b\u3057\u3088\u3046\u304b\u3068\u601d\u3063\u305f\u304c\u5358\u306b\u8a08\u7b97\u91cf\u304c\u591a\u304f\u306a\u308b\u3060\u3051\u306a\u306e\u3067\uff0c\u5099\u5fd8\u9332\u3068\u3057\u3066\u3002<\/p>\n<p><!--more--><\/p>\n<h3>3\u6b21\u5143\u306e\u30e9\u30d7\u30e9\u30b7\u30a2\u30f3<\/h3>\n<p>3\u6b21\u5143\u306e\u30e9\u30d7\u30e9\u30b7\u30a2\u30f3\u306f\u30c7\u30ab\u30eb\u30c8\u5ea7\u6a19 $x, y, z$ \u306e2\u968e\u504f\u5fae\u5206\u3067\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u5b9a\u7fa9\u3055\u308c\u308b\uff1a<\/p>\n<p>$$\\nabla^2 \\equiv \\dfrac{\\partial^2}{\\partial x^2} + \\dfrac{\\partial^2}{\\partial y^2}+ \\dfrac{\\partial^2}{\\partial z^2}$$<\/p>\n<h3>3\u6b21\u5143\u6975\u5ea7\u6a19<\/h3>\n<p>3\u6b21\u5143\u30c7\u30ab\u30eb\u30c8\u5ea7\u6a19 \\(x, y, z\\) \u304b\u3089\u6975\u5ea7\u6a19 \\(r, \\theta, \\phi\\) \u3078\u306e\u5ea7\u6a19\u5909\u63db\uff08\u3064\u307e\u308a\u5143\u306e\u5ea7\u6a19 \\(x, y, z\\) \u3092\u4f7f\u3063\u3066\u65b0\u3057\u3044\u5ea7\u6a19 \\(r, \\theta, \\phi\\) \u3092\u8868\u3059\u5f0f\uff09\u306f<\/p>\n<p>\\begin{eqnarray}<br \/>\nr &amp;=&amp; \\sqrt{x^2 + y^2 + z^2} \\\\<br \/>\n\\theta &amp;=&amp; \\tan^{-1} \\frac{\\sqrt{x^2 + y^2}}{z}\\\\<br \/>\n\\phi &amp;=&amp; \\tan^{-1} \\frac{y}{x}<br \/>\n\\end{eqnarray}<\/p>\n<p>\u305d\u306e\u9006\u5909\u63db\uff08\u3064\u307e\u308a\u65b0\u3057\u3044\u5ea7\u6a19 \\(r, \\theta, \\phi\\) \u3092\u4f7f\u3063\u3066\u5143\u306e\u5ea7\u6a19 \\(x, y, z\\) \u3092\u8868\u3059\u5f0f\uff09\u306f\uff0c<\/p>\n<p>\\begin{eqnarray}<br \/>\nx &amp;=&amp;\u00a0 r \\sin\\theta \\cos\\phi\\\\<br \/>\ny &amp;=&amp;\u00a0 r \\sin\\theta \\sin\\phi\\\\<br \/>\nz &amp;=&amp; r \\cos\\theta<br \/>\n\\end{eqnarray}<\/p>\n<h3>1\u968e\u504f\u5fae\u5206\u3092\u6975\u5ea7\u6a19\u3067\u66f8\u304d\u76f4\u3059<\/h3>\n<p>\u6975\u5ea7\u6a19 \\(r, \\theta, \\phi\\) \u3092 \\(x, y, z\\) \u30671\u968e\u504f\u5fae\u5206\u3057\u305f\u7d50\u679c\u3092\u6975\u5ea7\u6a19\u3067\u8868\u3059\u3002<\/p>\n<p>\\(r(x, y, z) \\) \u306e\u504f\u5fae\u5206\u306f\uff0c$u \\equiv x^2 + y^2 + z^2$ \u3068\u304a\u3044\u3066\u5408\u6210\u95a2\u6570\u306e\u504f\u5fae\u5206\u306e\u8981\u9818\u3067&#8230;<\/p>\n<p>\\begin{eqnarray}<br \/>\n\\frac{\\partial r}{\\partial x} &amp;=&amp; \\frac{d}{du} \\sqrt{u} \\cdot \\frac{\\partial u}{\\partial x} \\\\<br \/>\n&amp;=&amp; \\frac{1}{2} \\frac{1}{\\sqrt{u}} \\cdot 2 x \\\\<br \/>\n&amp;=&amp;\\frac{x}{r} = \\sin\\theta \\cos\\phi \\\\<br \/>\n\\frac{\\partial r}{\\partial y} &amp;=&amp; \\frac{y}{r} = \\sin\\theta \\sin\\phi \\\\<br \/>\n\\frac{\\partial r}{\\partial z} &amp;=&amp; \\frac{z}{r} = \\cos\\theta<br \/>\n\\end{eqnarray}<\/p>\n<p>\\(\\theta(x, y, z) \\) \u306e\u504f\u5fae\u5206\u306f\uff0c$u \\equiv \\dfrac{\\sqrt{x^2+y^2}}{z}$ \u3068\u304a\u3044\u3066\u5408\u6210\u95a2\u6570\u306e\u504f\u5fae\u5206\u306e\u8981\u9818\u3067&#8230;<\/p>\n<p>\\begin{eqnarray}<br \/>\n\\frac{\\partial \\theta}{\\partial x} &amp;=&amp; \\frac{d}{du} \\tan^{-1} {u} \\cdot \\frac{\\partial u}{\\partial x} \\\\<br \/>\n&amp;=&amp; \\frac{1}{1+u^2} \\frac{1}{z}\\cdot \\frac{x}{\\sqrt{x^2+y^2}} \\\\<br \/>\n&amp;=&amp;\\frac{z}{r^2}\u00a0 \\cdot \\frac{r \\sin\\theta \\cos\\phi}{r \\sin\\theta}\\\\<br \/>\n&amp;=&amp; \\frac{\\cos\\theta \\cos\\phi}{r} \\\\<br \/>\n\\frac{\\partial \\theta}{\\partial y} &amp;=&amp; \\frac{\\cos\\theta \\sin\\phi}{r} \\\\<br \/>\n\\frac{\\partial \\theta}{\\partial z} &amp;=&amp; -\\frac{\\sin\\theta}{r}<br \/>\n\\end{eqnarray}<\/p>\n<p>\\(\\phi(x, y, z) \\) \u306e\u504f\u5fae\u5206\u306f\uff0c$u \\equiv \\dfrac{y}{x}$ \u3068\u304a\u3044\u3066\u5408\u6210\u95a2\u6570\u306e\u504f\u5fae\u5206\u306e\u8981\u9818\u3067&#8230;<\/p>\n<p>\\begin{eqnarray}<br \/>\n\\frac{\\partial \\phi}{\\partial x} &amp;=&amp; \\frac{d}{du} \\tan^{-1} {u} \\cdot \\frac{\\partial u}{\\partial x} \\\\<br \/>\n&amp;=&amp; \\frac{1}{1+u^2} \\cdot \\left( -\\frac{y}{x^2} \\right)\\\\<br \/>\n&amp;=&amp;-\\frac{y}{x^2 + y^2}\\\\<br \/>\n&amp;=&amp; -\\frac{\\sin\\phi}{r \\sin\\theta} \\\\<br \/>\n\\frac{\\partial \\phi}{\\partial y} &amp;=&amp; \\frac{\\cos\\phi}{r \\sin\\theta} \\\\<br \/>\n\\frac{\\partial \\phi}{\\partial z} &amp;=&amp; 0<br \/>\n\\end{eqnarray}<\/p>\n<p>\u5f93\u3063\u3066\uff0c<\/p>\n<p>\\begin{eqnarray}<br \/>\n\\frac{\\partial }{\\partial x} &amp;=&amp;<br \/>\n\\frac{\\partial r}{\\partial x}\\frac{\\partial}{\\partial r}<br \/>\n+\\frac{\\partial\\theta}{\\partial x} \\frac{\\partial}{\\partial \\theta}<br \/>\n+\\frac{\\partial \\phi}{\\partial x}\\frac{\\partial}{\\partial \\phi} \\\\<br \/>\n&amp;=&amp; \\sin\\theta \\cos\\phi \\frac{\\partial}{\\partial r}<br \/>\n+\\frac{\\cos\\theta \\cos\\phi}{r} \\frac{\\partial}{\\partial \\theta}<br \/>\n-\\frac{\\sin\\phi}{r \\sin\\theta} \\frac{\\partial}{\\partial \\phi} \\\\<br \/>\n\\frac{\\partial }{\\partial y} &amp;=&amp;<br \/>\n\\sin\\theta \\sin\\phi \\frac{\\partial}{\\partial r}<br \/>\n+\\frac{\\cos\\theta \\sin\\phi}{r} \\frac{\\partial}{\\partial \\theta}<br \/>\n+\\frac{\\cos\\phi}{r \\sin\\theta} \\frac{\\partial}{\\partial \\phi} \\\\<br \/>\n\\frac{\\partial }{\\partial z} &amp;=&amp;<br \/>\n\\cos\\theta\u00a0 \\frac{\\partial}{\\partial r}<br \/>\n-\\frac{\\sin\\theta}{r} \\frac{\\partial}{\\partial \\theta}<br \/>\n\\end{eqnarray}<\/p>\n<h3>2\u968e\u504f\u5fae\u5206\u3092\u6975\u5ea7\u6a19\u3067\u66f8\u304d\u76f4\u3059<\/h3>\n<p>\\begin{eqnarray}<br \/>\n\\frac{\\partial^2}{\\partial x^2} &amp;=&amp; \\left(\\sin\\theta \\cos\\phi \\frac{\\partial}{\\partial r}<br \/>\n+\\frac{\\cos\\theta \\cos\\phi}{r} \\frac{\\partial}{\\partial \\theta}<br \/>\n-\\frac{\\sin\\phi}{r \\sin\\theta} \\frac{\\partial}{\\partial \\phi} \\right)^2 \\\\<br \/>\n&amp;=&amp; \\left(\\sin\\theta \\cos\\phi \\frac{\\partial}{\\partial r} \\right)<br \/>\n\\left(\\sin\\theta \\cos\\phi \\frac{\\partial}{\\partial r} \\right) \\\\<br \/>\n&amp;&amp; +\\left(\\sin\\theta \\cos\\phi \\frac{\\partial}{\\partial r} \\right)<br \/>\n\\left(\\frac{\\cos\\theta \\cos\\phi}{r} \\frac{\\partial}{\\partial \\theta} \\right) \\\\<br \/>\n&amp;&amp; +\\left(\\sin\\theta \\cos\\phi \\frac{\\partial}{\\partial r} \\right)<br \/>\n\\left( -\\frac{\\sin\\phi}{r \\sin\\theta} \\frac{\\partial}{\\partial \\phi}\\right) \\\\<br \/>\n%<br \/>\n&amp;&amp; +\\left(\\frac{\\cos\\theta \\cos\\phi}{r} \\frac{\\partial}{\\partial \\theta} \\right)<br \/>\n\\left(\\sin\\theta \\cos\\phi \\frac{\\partial}{\\partial r} \\right) \\\\<br \/>\n&amp;&amp; + \\left(\\frac{\\cos\\theta \\cos\\phi}{r} \\frac{\\partial}{\\partial \\theta} \\right)<br \/>\n\\left(\\frac{\\cos\\theta \\cos\\phi}{r} \\frac{\\partial}{\\partial \\theta} \\right) \\\\<br \/>\n&amp;&amp; + \\left(\\frac{\\cos\\theta \\cos\\phi}{r} \\frac{\\partial}{\\partial \\theta} \\right)<br \/>\n\\left( -\\frac{\\sin\\phi}{r \\sin\\theta} \\frac{\\partial}{\\partial \\phi}\\right) \\\\<br \/>\n%<br \/>\n&amp;&amp; +\\left( -\\frac{\\sin\\phi}{r \\sin\\theta} \\frac{\\partial}{\\partial \\phi}\\right)<br \/>\n\\left(\\sin\\theta \\cos\\phi \\frac{\\partial}{\\partial r} \\right) \\\\<br \/>\n&amp;&amp; + \\left( -\\frac{\\sin\\phi}{r \\sin\\theta} \\frac{\\partial}{\\partial \\phi}\\right)<br \/>\n\\left(\\frac{\\cos\\theta \\cos\\phi}{r} \\frac{\\partial}{\\partial \\theta} \\right) \\\\<br \/>\n&amp;&amp; + \\left( -\\frac{\\sin\\phi}{r \\sin\\theta} \\frac{\\partial}{\\partial \\phi}\\right)<br \/>\n\\left( -\\frac{\\sin\\phi}{r \\sin\\theta} \\frac{\\partial}{\\partial \\phi}\\right) \\\\<br \/>\n&amp;=&amp; \\sin^2\\theta \\cos^2\\phi \\frac{\\partial^2}{\\partial r^2}<br \/>\n+ \\frac{\\cos^2\\theta \\cos^2\\phi}{r^2} \\frac{\\partial^2}{\\partial \\theta^2}<br \/>\n+ \\frac{\\sin^2\\phi}{r^2 \\sin^2\\theta} \\frac{\\partial^2}{\\partial \\phi^2}\\\\<br \/>\n&amp;&amp; + \\frac{2}{r} \\sin\\theta\\cos\\theta \\cos^2\\phi \\frac{\\partial^2}{\\partial r \\partial\\theta} \\\\<br \/>\n&amp;&amp; -\\frac{2}{r} \\sin\\phi \\cos\\phi \\frac{\\partial^2}{\\partial r \\partial\\phi} \\\\<br \/>\n&amp;&amp; -\\frac{2}{r^2} \\frac{\\cos\\theta}{\\sin\\theta} \\sin\\phi \\cos\\phi \\frac{\\partial^2}{\\partial \\theta \\partial\\phi} \\\\<br \/>\n&amp;&amp; +\\frac{1}{r} \\left(\\cos^2\\theta \\cos^2\\phi + \\sin^2\\phi \\right) \\frac{\\partial}{\\partial r} \\\\<br \/>\n&amp;&amp; + \\frac{1}{r^2} \\left(\\frac{\\cos\\theta}{\\sin\\theta} \\sin^2\\phi -2 \\sin\\theta \\cos\\theta \\cos^2\\phi \\right)\\frac{\\partial}{\\partial \\theta} \\\\<br \/>\n&amp;&amp; +\\frac{2 \\sin\\phi \\cos\\phi}{r^2 \\sin^2\\theta} \\frac{\\partial}{\\partial \\phi} \\\\<br \/>\n%%<br \/>\n\\frac{\\partial^2}{\\partial y^2} &amp;=&amp;\\sin^2\\theta \\sin^2\\phi \\frac{\\partial^2}{\\partial r^2}<br \/>\n+ \\frac{\\cos^2\\theta \\sin^2\\phi}{r^2} \\frac{\\partial^2}{\\partial \\theta^2}<br \/>\n+ \\frac{\\cos^2\\phi}{r^2 \\sin^2\\theta} \\frac{\\partial^2}{\\partial \\phi^2}\\\\<br \/>\n&amp;&amp; + \\frac{2}{r} \\sin\\theta\\cos\\theta \\sin^2\\phi \\frac{\\partial^2}{\\partial r \\partial\\theta} \\\\<br \/>\n&amp;&amp; +\\frac{2}{r} \\sin\\phi \\cos\\phi \\frac{\\partial^2}{\\partial r \\partial\\phi} \\\\<br \/>\n&amp;&amp; +\\frac{2}{r^2} \\frac{\\cos\\theta}{\\sin\\theta} \\sin\\phi \\cos\\phi \\frac{\\partial^2}{\\partial \\theta \\partial\\phi} \\\\<br \/>\n&amp;&amp; +\\frac{1}{r} \\left(\\cos^2\\theta \\sin^2\\phi + \\cos^2\\phi \\right) \\frac{\\partial}{\\partial r} \\\\<br \/>\n&amp;&amp; + \\frac{1}{r^2} \\left(\\frac{\\cos\\theta}{\\sin\\theta} \\cos^2\\phi -2 \\sin\\theta \\cos\\theta \\sin^2\\phi \\right)\\frac{\\partial}{\\partial \\theta} \\\\<br \/>\n&amp;&amp; -\\frac{2 \\sin\\phi \\cos\\phi}{r^2 \\sin^2\\theta} \\frac{\\partial}{\\partial \\phi} \\\\<br \/>\n%%<br \/>\n\\frac{\\partial^2}{\\partial z^2}<br \/>\n&amp;=&amp;<br \/>\n\\cos^2\\theta \\frac{\\partial^2}{\\partial r^2}<br \/>\n+ \\frac{1}{r^2} \\sin^2\\theta \\frac{\\partial^2}{\\partial \\theta^2} \\\\<br \/>\n&amp;&amp; -\\frac{2}{r} \\sin\\theta \\cos\\theta \\frac{\\partial^2}{\\partial r \\partial\\theta} \\\\<br \/>\n&amp;&amp; + \\frac{1}{r} \\sin^2\\theta \\frac{\\partial}{\\partial r} + \\frac{2}{r^2} \\sin\\theta \\cos\\theta \\frac{\\partial}{\\partial\\theta}<br \/>\n\\end{eqnarray}<\/p>\n<p>&nbsp;<\/p>\n<h3>3\u6b21\u5143\u306e\u30e9\u30d7\u30e9\u30b7\u30a2\u30f3\u3092\u6975\u5ea7\u6a19\u3067<\/h3>\n<p>\u6700\u7d42\u7684\u306b\uff0c<\/p>\n<p>\\begin{eqnarray}<br \/>\n\\nabla^2 &amp;=&amp; \\frac{\\partial^2}{\\partial x^2}+\\frac{\\partial^2}{\\partial y^2}+\\frac{\\partial^2}{\\partial z^2} \\\\<br \/>\n&amp;=&amp; \\frac{\\partial^2}{\\partial r^2} +\\frac{2}{r} \\frac{\\partial}{\\partial r}<br \/>\n+\\frac{1}{r^2} \\frac{\\partial^2}{\\partial\\theta^2} + \\frac{1}{r^2} \\frac{\\cos\\theta}{\\sin\\theta}\\frac{\\partial}{\\partial \\theta}<br \/>\n+ \\frac{1}{r^2 \\sin^2\\theta} \\frac{\\partial^2}{\\partial \\phi^2} \\\\<br \/>\n&amp;=&amp; \\frac{1}{r^2} \\frac{\\partial}{\\partial r} \\left( r^2 \\frac{\\partial}{\\partial r}\\right)<br \/>\n+\\frac{1}{r^2\\sin\\theta} \\frac{\\partial}{\\partial\\theta} \\left(\\sin\\theta\\frac{\\partial}{\\partial\\theta} \\right)<br \/>\n+ \\frac{1}{r^2 \\sin^2\\theta} \\frac{\\partial^2}{\\partial \\phi^2}<br \/>\n\\end{eqnarray}<\/p>\n<h3>\u53c2\u8003\uff1a\u8a08\u91cf\u30c6\u30f3\u30bd\u30eb\u3092\u4f7f\u3063\u3066\u8868\u3059<\/h3>\n<p>\u5c06\u6765\uff0c\u300c<span style=\"font-family: helvetica, arial, sans-serif;\"><strong><a href=\"https:\/\/home.hirosaki-u.ac.jp\/relativity\/%e4%b8%80%e8%88%ac%e7%9b%b8%e5%af%be%e8%ab%96%e7%9a%84%e6%99%82%e7%a9%ba%e3%81%ae%e8%a1%a8%e3%81%97%e6%96%b9\/%e5%85%b1%e5%a4%89%e5%be%ae%e5%88%86%e3%81%ae%e5%ae%9a%e7%be%a9%e3%81%a8%e3%83%aa%e3%83%83%e3%83%81%e3%81%ae%e6%81%92%e7%ad%89%e5%bc%8f\/%e3%83%99%e3%82%af%e3%83%88%e3%83%ab%e3%81%ae%e7%99%ba%e6%95%a3%e3%82%84%e3%83%a9%e3%83%97%e3%83%a9%e3%82%b7%e3%82%a2%e3%83%b3%e3%82%92%e5%85%b1%e5%a4%89%e5%be%ae%e5%88%86%e3%81%a7%e7%90%86%e8%a7%a3\/\" target=\"_blank\" rel=\"noopener\">\u30d9\u30af\u30c8\u30eb\u306e\u767a\u6563\u3084\u30e9\u30d7\u30e9\u30b7\u30a2\u30f3\u3092\u5171\u5909\u5fae\u5206\u3067\u7406\u89e3\u3059\u308b<\/a><\/strong><\/span>\u300d\u306e\u30da\u30fc\u30b8\u3067\u8a08\u91cf\u30c6\u30f3\u30bd\u30eb\u3084\u5171\u5909\u5fae\u5206\u3092\u5b66\u3093\u3060\u3042\u3068\u3067\u3053\u306e\u30da\u30fc\u30b8\u3092\u898b\u304b\u3048\u3057\u3066\u307f\u308b\u3068\uff0c3\u6b21\u5143\u6975\u5ea7\u6a19\u306b\u304a\u3051\u308b\u8a08\u91cf\u30c6\u30f3\u30bd\u30eb $g_{ij}$ \u306e\u6210\u5206\u304c<\/p>\n<p>$$<br \/>\ng_{ij} = \\left(\\begin{array}{ccc}<br \/>\ng_{rr} &amp; g_{r\\theta} &amp; g_{r\\phi} \\\\<br \/>\ng_{\\theta r} &amp; g_{\\theta\\theta} &amp; g_{\\theta\\phi} \\\\<br \/>\ng_{\\phi r} &amp; g_{\\phi\\theta} &amp; g_{\\phi\\phi}<br \/>\n\\end{array}\\right)<br \/>\n=\u00a0 \\left(\\begin{array}{ccc}<br \/>\n1 &amp; 0&amp; 0 \\\\<br \/>\n0 &amp; r^2&amp; 0 \\\\<br \/>\n0 &amp; 0 &amp; r^2 \\sin^2\\theta<br \/>\n\\end{array}\\right)<br \/>\n$$<\/p>\n<p>\u3067\u3042\u308a\uff0c\u8a08\u91cf\u30c6\u30f3\u30bd\u30eb\u3092\u884c\u5217\u3068\u307f\u306a\u3057\u305f\u3068\u304d\u306e\u884c\u5217\u5f0f $g$ \u306f<\/p>\n<p>$$g \\equiv \\det (g_{ij}) = r^4 \\sin^2\\theta, \\ \\therefore\\ \\sqrt{g} = r^2 \\sin\\theta$$<\/p>\n<p>\u307e\u305f\uff0c\u8a08\u91cf\u30c6\u30f3\u30bd\u30eb\u306e\u9006\u884c\u5217 $g^{ij}$ \u306f<\/p>\n<p>$$<br \/>\ng^{ij} = \\left(\\begin{array}{ccc}<br \/>\ng^{rr} &amp; g^{r\\theta} &amp; g^{r\\phi} \\\\<br \/>\ng^{\\theta r} &amp; g^{\\theta\\theta} &amp; g^{\\theta\\phi} \\\\<br \/>\ng^{\\phi r} &amp; g^{\\phi\\theta} &amp; g^{\\phi\\phi}<br \/>\n\\end{array}\\right)<br \/>\n=\u00a0 \\left(\\begin{array}{ccc}<br \/>\n1 &amp; 0&amp; 0 \\\\<br \/>\n0 &amp; \\dfrac{1}{r}&amp; 0 \\\\<br \/>\n0 &amp; 0 &amp; \\dfrac{1}{r^{2} \\sin^{2}\\theta}<br \/>\n\\end{array}\\right)$$<\/p>\n<p>\u3053\u308c\u3089\u3092\u4f7f\u3046\u30683\u6b21\u5143\u306e\u30e9\u30d7\u30e9\u30b7\u30a2\u30f3\u304c<\/p>\n<p>\\begin{eqnarray}<br \/>\n\\nabla^2 &amp;=&amp; \\frac{1}{\\sqrt{g}} \\partial_r \\left( \\sqrt{g} \\ r^{rr}\\\u00a0 \\partial_r\\right)<br \/>\n+ \\frac{1}{\\sqrt{g}} \\partial_{\\theta} \\left( \\sqrt{g} \\ r^{{\\theta}{\\theta}}\\\u00a0 \\partial_{\\theta}\\right)<br \/>\n+ \\frac{1}{\\sqrt{g}} \\partial_{\\phi} \\left( \\sqrt{g} \\ r^{{\\phi} {\\phi} } \\ \\partial_{\\phi} \\right)\\\\<br \/>\n&amp;=&amp; \\frac{1}{r^2 \\sin\\theta} \\partial_r \\left( r^2 \\sin\\theta \\ \\partial_r\\right)<br \/>\n+ \\frac{1}{r^2 \\sin\\theta} \\partial_{\\theta} \\left( \\frac{r^2 \\sin\\theta}{ \\ r^{2}}\\ \\partial_{\\theta}\\right)<br \/>\n+ \\frac{1}{r^2 \\sin\\theta}\\partial_{\\phi} \\left( \\frac{r^2 \\sin\\theta}{r^{2 } \\sin^{2}\\theta}\\ \\partial_{\\phi} \\right)\\\\<br \/>\n&amp;=&amp; \\frac{1}{r^2 } \\partial_r \\left( r^2 \\ \\partial_r\\right)<br \/>\n+ \\frac{1}{r^2 \\sin\\theta} \\partial_{\\theta} \\left( \\sin\\theta \\ \\partial_{\\theta}\\right)<br \/>\n+ \\frac{1}{r^2 \\sin^2\\theta}\\partial_{\\phi} \\left( \\partial_{\\phi} \\right)<br \/>\n\\end{eqnarray}<\/p>\n<p>\u3068\u66f8\u3051\u3066\u3044\u308b\u306e\u3060\u306a\u3041\u3068\u3044\u3046\u3053\u3068\u304c\u308f\u304b\u308b\u3088\u3046\u306b\u306a\u308b\u3068\u601d\u3046\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5408\u6210\u95a2\u6570\u306e\u504f\u5fae\u5206\u306e\u5fdc\u7528\u3068\u3057\u3066\uff0c\uff08\u30c7\u30ab\u30eb\u30c8\u5ea7\u6a19\u3067\u5b9a\u7fa9\u3055\u308c\u305f\uff093\u6b21\u5143\u306e\u30e9\u30d7\u30e9\u30b7\u30a2\u30f3 $\\nabla^2 = \\dfrac{\\partial^2}{\\partial x^2} + \\dfrac{\\partial^2}{\\partial y^2}+ \\dfrac{\\partial^2}{\\partial z^2}$ \u3092\u6975\u5ea7\u6a19 $r, \\theta, \\phi$ \u3092\u4f7f\u3063\u3066\u8868\u3057\u3066\u307f\u308b\u3002\u7df4\u7fd2\u554f\u984c\u306b\u3057\u3088\u3046\u304b\u3068\u601d\u3063\u305f\u304c\u5358\u306b\u8a08\u7b97\u91cf\u304c\u591a\u304f\u306a\u308b\u3060\u3051\u306a\u306e\u3067\uff0c\u5099\u5fd8\u9332\u3068\u3057\u3066\u3002<\/p><p><a class=\"more-link btn\" href=\"https:\/\/home.hirosaki-u.ac.jp\/relativity\/%e7%90%86%e5%b7%a5%e7%b3%bb%e3%81%ae%e6%95%b0%e5%ad%a6c\/%e5%81%8f%e5%be%ae%e5%88%86%ef%bc%9a%e5%a4%9a%e5%a4%89%e6%95%b0%e9%96%a2%e6%95%b0%e3%81%ae%e5%be%ae%e5%88%86\/%e5%90%88%e6%88%90%e9%96%a2%e6%95%b0%e3%81%ae%e5%81%8f%e5%be%ae%e5%88%86%e6%b3%95\/3%e6%ac%a1%e5%85%83%e3%81%ae%e3%83%a9%e3%83%97%e3%83%a9%e3%82%b7%e3%82%a2%e3%83%b3%e3%82%92%e6%a5%b5%e5%ba%a7%e6%a8%99%e3%81%a7%e8%a1%a8%e3%81%99\/\">\u7d9a\u304d\u3092\u8aad\u3080<\/a><\/p>\n","protected":false},"author":33,"featured_media":0,"parent":2325,"menu_order":20,"comment_status":"closed","ping_status":"closed","template":"","meta":{"inline_featured_image":false,"footnotes":""},"class_list":["post-10300","page","type-page","status-publish","hentry","nodate","item-wrap"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/home.hirosaki-u.ac.jp\/relativity\/wp-json\/wp\/v2\/pages\/10300","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/home.hirosaki-u.ac.jp\/relativity\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/home.hirosaki-u.ac.jp\/relativity\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/home.hirosaki-u.ac.jp\/relativity\/wp-json\/wp\/v2\/users\/33"}],"replies":[{"embeddable":true,"href":"https:\/\/home.hirosaki-u.ac.jp\/relativity\/wp-json\/wp\/v2\/comments?post=10300"}],"version-history":[{"count":39,"href":"https:\/\/home.hirosaki-u.ac.jp\/relativity\/wp-json\/wp\/v2\/pages\/10300\/revisions"}],"predecessor-version":[{"id":10400,"href":"https:\/\/home.hirosaki-u.ac.jp\/relativity\/wp-json\/wp\/v2\/pages\/10300\/revisions\/10400"}],"up":[{"embeddable":true,"href":"https:\/\/home.hirosaki-u.ac.jp\/relativity\/wp-json\/wp\/v2\/pages\/2325"}],"wp:attachment":[{"href":"https:\/\/home.hirosaki-u.ac.jp\/relativity\/wp-json\/wp\/v2\/media?parent=10300"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}