<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><meta http-equiv="content-type" content="text/html; charset=utf-8"><div style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><meta http-equiv="content-type" content="text/html; charset=utf-8"><div style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><meta http-equiv="content-type" content="text/html; charset=utf-8"><div style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><meta http-equiv="content-type" content="text/html; charset=utf-8"><div style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><meta http-equiv="content-type" content="text/html; charset=utf-8"><div style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">
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<div dir="auto">皆様<br>
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東大数理・複素解析幾何セミナーのお知らせです。</div><div dir="auto"><h3 style="margin: 3px 0px 8px; padding: 5px 0px; font-stretch: inherit; font-size: 14px; line-height: inherit; font-family: メイリオ, Meiryo, "ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", Osaka, "ＭＳ Ｐゴシック", "MS PGothic", Helvetica, Arial, sans-serif; font-size-adjust: inherit; font-kerning: inherit; font-variant-alternates: inherit; font-variant-ligatures: inherit; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-variant-position: inherit; font-feature-settings: inherit; font-optical-sizing: inherit; font-variation-settings: inherit; vertical-align: baseline; border-top-width: 1px; border-top-style: dotted; border-top-color: rgb(33, 127, 196); border-bottom-width: 1px; border-bottom-style: dotted; border-bottom-color: rgb(33, 127, 196); overflow: hidden; caret-color: rgb(51, 51, 51); color: rgb(51, 51, 51);">2023年06月19日(月)</h3><div class="seminar_naiyo" style="margin: 0px 0px 20px; padding: 0px; font-stretch: inherit; font-size: 13px; line-height: inherit; font-family: メイリオ, Meiryo, "ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", Osaka, "ＭＳ Ｐゴシック", "MS PGothic", Helvetica, Arial, sans-serif; font-size-adjust: inherit; font-kerning: inherit; font-variant-alternates: inherit; font-variant-ligatures: inherit; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-variant-position: inherit; font-feature-settings: inherit; font-optical-sizing: inherit; font-variation-settings: inherit; vertical-align: baseline; caret-color: rgb(51, 51, 51); color: rgb(51, 51, 51);">10:30-12:00 数理科学研究科棟(駒場) 128号室<br><strong style="margin: 0px; padding: 0px; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; font-size-adjust: inherit; font-kerning: inherit; font-variant-alternates: inherit; font-variant-ligatures: inherit; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-variant-position: inherit; font-feature-settings: inherit; font-optical-sizing: inherit; font-variation-settings: inherit; vertical-align: baseline;">本多 宣博 氏</strong> (東京工業大学)<br>3次元不定値Zoll多様体の新しい構成方法<br><div class="waku" style="margin: 5px 0px 8px; padding: 9px; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; font-size-adjust: inherit; font-kerning: inherit; font-variant-alternates: inherit; font-variant-ligatures: inherit; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-variant-position: inherit; font-feature-settings: inherit; font-optical-sizing: inherit; font-variation-settings: inherit; vertical-align: baseline; border: 1px solid rgb(204, 204, 204); background-color: rgb(239, 239, 239);">[ 講演概要 ]<br>ペンローズ対応は多様体上の特殊な幾何構造と複素多様体の間の対応関係を与えるものであるが、その一つとして、3次元多様体上のEinstein-Weyl構造と複素曲面の間の対応がある。後者の複素曲面をミニツイスター空間という。本講演では、任意種数の超楕円曲線から自然な方法でコンパクトミニツイスター空間が構成できることと、それから得られる3次元実Einstein-Weyl多様体がZoll性とよばれる顕著な幾何的性質をもつことを示す。Zoll性とはすべての測地線が閉じているというものであり、その代表的な例は球面である。今回得られた3次元Einstein-Weyl多様体は不定値であり、考える測地線は空間的なものである。これらのEinstein-Weyl多様体は arXiv:2208.13567 で与えられたものの一般化とみなすことができる。</div>[ 参考URL ]<br></div><h3 style="margin: 3px 0px 8px; padding: 5px 0px; font-stretch: inherit; font-size: 14px; line-height: inherit; font-family: メイリオ, Meiryo, "ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", Osaka, "ＭＳ Ｐゴシック", "MS PGothic", Helvetica, Arial, sans-serif; font-size-adjust: inherit; font-kerning: inherit; font-variant-alternates: inherit; font-variant-ligatures: inherit; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-variant-position: inherit; font-feature-settings: inherit; font-optical-sizing: inherit; font-variation-settings: inherit; vertical-align: baseline; border-top-width: 1px; border-top-style: dotted; border-top-color: rgb(33, 127, 196); border-bottom-width: 1px; border-bottom-style: dotted; border-bottom-color: rgb(33, 127, 196); overflow: hidden; caret-color: rgb(51, 51, 51); color: rgb(51, 51, 51);"><a href="https://u-tokyo-ac-jp.zoom.us/meeting/register/tZEqceqsrTIjEtRxenSMdPogvCxlWzAogj5A" style="font-family: inherit; font-size: inherit; margin: 0px; padding: 0px; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; font-size-adjust: inherit; font-kerning: inherit; font-variant-alternates: inherit; font-variant-ligatures: inherit; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-variant-position: inherit; font-feature-settings: inherit; font-optical-sizing: inherit; font-variation-settings: inherit; vertical-align: baseline; color: rgb(33, 127, 196); text-decoration: none;">https://u-tokyo-ac-jp.zoom.us/meeting/register/tZEqceqsrTIjEtRxenSMdPogvCxlWzAogj5A</a>Zoom URL・ID・パスワードなどは１年間同じものを使うので登録は一度で大丈夫です．</h3>
今後の予定はこちら<br>
<a href="https://www.ms.u-tokyo.ac.jp/seminar/geocomp/future.html" target="_blank">https://www.ms.u-tokyo.ac.jp/seminar/geocomp/future.html</a><br>
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講演者も募集中です。<br>
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世話人<br>
平地 健吾、高山 茂晴</div>
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