{"version":"1.0","provider_name":"KMI - Nagoya University","provider_url":"https:\/\/www.kmi.nagoya-u.ac.jp\/eng","title":"Causal structures with curvature couplings in kinetic terms - KMI - Nagoya University","type":"rich","width":600,"height":338,"html":"<blockquote class=\"wp-embedded-content\" data-secret=\"ZFOpvE0nT5\"><a href=\"https:\/\/www.kmi.nagoya-u.ac.jp\/eng\/seminar\/1041\/\">Causal structures with curvature couplings in kinetic terms<\/a><\/blockquote><iframe sandbox=\"allow-scripts\" security=\"restricted\" src=\"https:\/\/www.kmi.nagoya-u.ac.jp\/eng\/seminar\/1041\/embed\/#?secret=ZFOpvE0nT5\" width=\"600\" height=\"338\" title=\"&#8220;Causal structures with curvature couplings in kinetic terms&#8221; &#8212; KMI - Nagoya University\" data-secret=\"ZFOpvE0nT5\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" class=\"wp-embedded-content\"><\/iframe><script type=\"text\/javascript\">\n\/* <![CDATA[ *\/\n\/*! This file is auto-generated *\/\n!function(d,l){\"use strict\";l.querySelector&&d.addEventListener&&\"undefined\"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!\/[^a-zA-Z0-9]\/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret=\"'+t.secret+'\"]'),o=l.querySelectorAll('blockquote[data-secret=\"'+t.secret+'\"]'),c=new RegExp(\"^https?:$\",\"i\"),i=0;i<o.length;i++)o[i].style.display=\"none\";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute(\"style\"),\"height\"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):\"link\"===t.message&&(r=new URL(s.getAttribute(\"src\")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener(\"message\",d.wp.receiveEmbedMessage,!1),l.addEventListener(\"DOMContentLoaded\",function(){for(var e,t,s=l.querySelectorAll(\"iframe.wp-embedded-content\"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute(\"data-secret\"))||(t=Math.random().toString(36).substring(2,12),e.src+=\"#?secret=\"+t,e.setAttribute(\"data-secret\",t)),e.contentWindow.postMessage({message:\"ready\",secret:t},\"*\")},!1)))}(window,document);\n\/* ]]> *\/\n<\/script>\n","description":"The couplings with curvature in kinetic terms would arise as corrections from the quantum gravity theory, such as the string theory. The curvature coupling in general makes the propagation to be superluminal. In the theory with superluminal modes, the causal analysis with null curves is meaningless, and thus the causal structures are nontrivial. Especially, we have to define black holes based on the fastest propagation. In this talk, Gauss-Bonnet gravity will be discussed as the simplest model. We could say &hellip;"}