{"id":2222,"date":"2012-05-07T23:05:51","date_gmt":"2012-05-07T15:05:51","guid":{"rendered":"http:\/\/wamath.sinaapp.com\/?p=2222"},"modified":"2012-05-07T23:05:51","modified_gmt":"2012-05-07T15:05:51","slug":"bott-residue-formula","status":"publish","type":"post","link":"https:\/\/lttt.vanabel.cn\/?p=2222","title":{"rendered":"Bott Residue Formula"},"content":{"rendered":"<p>We make the same assumptions as in previous section. Let $i_1,\\cdots,i_k$ be $k$ positive even integers. For any $p\\in\\mathrm{zero}(K)$ and $1\\leq j \\leq k$, set<br \/>\n\\[<br \/>\n\\lambda^{i_j}(p)=\\lambda_1^{i_j}+\\cdots+\\lambda_l^{i_j}.<br \/>\n\\]By following theorem, we reduce the computation of characteristic numbers of $TM$ to quantities on $\\mathrm{zero}(K)$.<br \/>\n<!--more--><br \/>\n\\begin{thm}<br \/>\nIf $i_1+\\cdots+i_k=l$, then<br \/>\n\\[<br \/>\n\\int_M \\tr\\left[\\left(R^{TM}\\right)^{i_1}\\right]\\cdots\\tr \\left[\\left(R^{TM}\\right)^{i_k}\\right]<br \/>\n=(2\\pi\\sqrt{-1})^l\\sum_{p\\in\\mathrm{zero}(K)}\\frac{2^k\\lambda^{i_1}(p)\\cdots\\lambda^{i_k}(p)}{\\lambda(p)},<br \/>\n\\]where $R^{TM}$ is the curvature of the Levi-Civita connection $\\nabla^{TM}$. And, if $i_1+\\cdots+i_k&lt;l$, then<br \/>\n\\[<br \/>\n\\sum_{p\\in\\mathrm{zero}(K)}\\frac{2^k\\lambda^{i_1}(p)\\cdots\\lambda^{i_k}(p)}{\\lambda(p)}=0.<br \/>\n\\]<br \/>\n\\end{thm}<br \/>\n\\begin{proof}<br \/>\nWe define a operator<br \/>\n\\[<br \/>\nL_K=\\nabla^{TM}_K-\\left.\\mathcal{L}_K\\right|_{\\Gamma(TM)}.<br \/>\n\\]Obviously, for any $Y\\in \\Gamma(TM)$<br \/>\n\\[<br \/>\nL_KY=\\nabla^{TM}_KY-[K,L]=\\left(\\nabla^{TM}K\\right)(Y).<br \/>\n\\]i.e., $L_K=\\left(\\nabla^{TM}K\\right)\\in\\Gamma(\\mathrm{End}(TM))=\\Omega^0(M,\\mathrm{End}(TM))$. We need to find a $\\omega\\in\\Omega^*(M)$ satisfied $\\rd_K\\omega=0$ and<br \/>\n\\[<br \/>\n\\int_{M}\\omega=\\int_M \\tr\\left[\\left(R^{TM}\\right)^{i_1}\\right]\\cdots\\tr \\left[\\left(R^{TM}\\right)^{i_k}\\right].<br \/>\n\\]<br \/>\nOf course, it is necessary that we can calculate $\\int_{M}\\omega$.<br \/>\nFor any integer $h$, if we have $\\rd_K\\tr\\left[(R^{TM}+L_K)^h\\right]=0$. Since<br \/>\n\\[<br \/>\n\\left[\\tr\\left[\\left(R^{TM}+L_K\\right)^{i_1}\\right]\\cdots\\tr \\left[\\left(R^{TM}+L_K\\right)^{i_k}\\right]\\right]^{[\\mathrm{top}]}=\\tr\\left[\\left(R^{TM}\\right)^{i_1}\\right]\\cdots\\tr \\left[\\left(R^{TM}\\right)^{i_k}\\right],<br \/>\n\\]it means<br \/>\n\\[<br \/>\n\\int_M \\tr\\left[\\left(R^{TM}\\right)^{i_1}\\right]\\cdots\\tr \\left[\\left(R^{TM}\\right)^{i_k}\\right]=\\int_{M}\\tr\\left[\\left(R^{TM}+L_K\\right)^{i_1}\\right]\\cdots\\tr \\left[\\left(R^{TM}\\right)^{i_k}+L_K\\right].<br \/>\n\\]<br \/>\nBy the Berline-Vergne localization formula, one can easily obtain<br \/>\n\\[<br \/>\n\\int_M \\tr\\left[\\left(R^{TM}\\right)^{i_1}\\right]\\cdots\\tr \\left[\\left(R^{TM}\\right)^{i_k}\\right]=(2\\pi)^l\\sum_{p\\in\\mathrm{zero}(K)}\\frac{\\tr\\left[\\left(L_K(p)\\right)^{i_1}\\right]\\cdots\\tr \\left[\\left(L_K(p)\\right)^{i_k}\\right]}{\\lambda(p)}<br \/>\n\\]On the local coordinate system $\\left(U_p,(x^1,\\cdots,x^{2l})\\right)$ from the previous section,<br \/>\n\\[<br \/>\nK=\\sum_{i=1}^{l}\\lambda_i\\left(x^{2i}\\frac{\\partial}{\\partial x^{2i-1}}-x^{2i-1}\\frac{\\partial}{\\partial x^{2i}}\\right).<br \/>\n\\]And, we know $L_K=\\nabla^{TM}K$ is a anti-symmetry operator. So on $U_p$,<br \/>\n\\[<br \/>\nL_K(p)=\\begin{pmatrix}<br \/>\n         0          &amp; \\lambda_1 &amp;         &amp;             &amp;\\\\<br \/>\n         -\\lambda_1 &amp; 0         &amp;         &amp;             &amp;\\\\<br \/>\n                    &amp;           &amp;  \\ddots &amp;             &amp;\\\\<br \/>\n                    &amp;           &amp;         &amp; 0           &amp; \\lambda_l\\\\<br \/>\n                    &amp;           &amp;         &amp; -\\lambda_l  &amp; 0<br \/>\n       \\end{pmatrix},<br \/>\n\\]then $\\left(L_K(p)\\right)^2=-\\mathrm{diag}\\left\\{\\lambda_1^2,\\lambda_1^2,\\cdots,\\lambda_l^2,\\lambda_l^2\\right\\}$.<br \/>\nThus, for each $1\\leq j \\leq k$, $\\tr \\left[\\left(L_K(p)\\right)^{i_j}\\right]=2(-1)^{i_j\/2}\\lambda^{i_j}(p)$. From this result,<br \/>\n\\[<br \/>\n\\int_M \\tr\\left[\\left(R^{TM}\\right)^{i_1}\\right]\\cdots\\tr \\left[\\left(R^{TM}\\right)^{i_k}\\right]<br \/>\n=(2\\pi\\sqrt{-1})^l\\sum_{p\\in\\mathrm{zero}(K)}\\frac{2^k\\lambda^{i_1}(p)\\cdots\\lambda^{i_k}(p)}{\\lambda(p)}.<br \/>\n\\]<br \/>\nOtherwise, we have<br \/>\n\\begin{align*}<br \/>\n(\\rd+i_K)\\tr\\left[\\left(R^{TM}+L_K\\right)^h\\right]=&amp;\\rd\\tr\\left[\\left(R^{TM}+L_K\\right)^h\\right]+i_K\\tr\\left[\\left(R^{TM}+L_K\\right)^h\\right]\\\\<br \/>\n=&amp;\\tr\\left[\\nabla^{TM},\\left(R^{TM}+L_K\\right)^h\\right]+\\tr\\left[i_K\\left(R^{TM}+L_K\\right)^h\\right]\\\\<br \/>\n=&amp;\\tr\\left[\\nabla^{TM},\\left(R^{TM}+L_K\\right)^h\\right]+\\tr\\left[i_K, \\left(R^{TM}+L_K\\right)^h\\right]\\\\<br \/>\n=&amp;\\tr\\left[\\nabla^{TM}+i_K,\\left(R^{TM}+L_K\\right)^h\\right];<br \/>\n\\end{align*}<br \/>\n\\begin{align*}<br \/>\n\\left(\\nabla^{TM}+i_K\\right)^2=&amp;\\left(\\nabla\\right)^2+(i_K)^2+\\nabla^{TM}\\circ i_K+ i_K\\circ \\nabla^{TM}\\\\<br \/>\n=&amp;R^{TM}+0+\\nabla^{TM}\\circ i_K+ i_K\\circ \\nabla^{TM}\\\\<br \/>\n=&amp;R^{TM}+0+\\nabla^{TM}\\circ i_K+ i_K\\left(\\nabla^{TM}\\right)-\\nabla^{TM}\\circ i_K\\\\<br \/>\n=&amp;R^{TM}+\\nabla^{TM}_K\\\\<br \/>\n=&amp;R^{TM}+L_K+\\mathcal{L}_K;<br \/>\n\\end{align*}<br \/>\ni.e.,$R^{TM}+L_K=\\left(\\nabla^{TM}+i_K\\right)^2-\\mathcal{L}_K$. By Bianchi identity, one can obtain<br \/>\n\\begin{align*}<br \/>\n\\left[\\nabla^{TM}+i_K, R^{TM}+L_K \\right]=&amp;\\left[\\nabla^{TM}+i_K,\\left(\\nabla^{TM}+i_K\\right)^2-\\mathcal{L}_K\\right]\\\\<br \/>\n=&amp;-\\left[\\nabla^{TM}+i_K,L_K\\right].<br \/>\n\\end{align*}<br \/>\nSince both $\\nabla^{TM}$ and $K$ are $S^1$-invariant, one has<br \/>\n\\[<br \/>\n\\left[\\nabla^{TM},\\mathcal{L}_K\\right]=0,\\quad \\left[i_K,\\mathcal{L}_K\\right]=0.<br \/>\n\\]Hence $\\left[\\nabla^{TM}+i_K, R^{TM}+L_K \\right]=0$. It shows<br \/>\n\\[<br \/>\n\\rd_K\\tr\\left[\\left( R^{TM}+L_K\\right)^h\\right]=\\tr\\left[\\nabla^{TM}+i_K, R^{TM}+L_K \\right]=0.<br \/>\n\\]<br \/>\n\\end{proof}<\/p>\n","protected":false},"excerpt":{"rendered":"<p>We make the same assumptions as in previ &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"more-link\" href=\"https:\/\/lttt.vanabel.cn\/?p=2222\"> <span class=\"screen-reader-text\">Bott Residue Formula<\/span> \u9605\u8bfb\u66f4\u591a &raquo;<\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17,12],"tags":[],"class_list":["post-2222","post","type-post","status-publish","format-standard","hentry","category-index-theory","category-mathnotes"],"_links":{"self":[{"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=\/wp\/v2\/posts\/2222","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2222"}],"version-history":[{"count":0,"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=\/wp\/v2\/posts\/2222\/revisions"}],"wp:attachment":[{"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2222"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2222"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lttt.vanabel.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2222"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}