{"id":798,"date":"2008-08-17T17:34:32","date_gmt":"2008-08-17T22:34:32","guid":{"rendered":"http:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=798"},"modified":"2012-07-28T15:10:39","modified_gmt":"2012-07-28T19:10:39","slug":"strings-2008","status":"publish","type":"post","link":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=798","title":{"rendered":"Strings 2008"},"content":{"rendered":"

Strings 2008 <\/a>starts tomorrow at CERN, with about 400 physicists in attendance. CERN will be providing a live webcast<\/a> for the rest of us. The timetable of the talks is here<\/a>. The first afternoon will be devoted not to string theory, but to the LHC.<\/p>\n

Those in attendance without their own blogs are encouraged to report on the goings-on by writing comments here when they get bored by the talks. I’ll try and watch some of the talks (or at least look at the slides), and use this posting to write about them.<\/p>\n

Update<\/strong>: I’m not likely to be up early enough to catch the morning talks on the webcast, but Lubos is, so you can follow his virtual live-blogging<\/a>.<\/p>\n

Update<\/strong>: Live, the conference seems to be suffering from not always being up to the technology of displaying slides on a Mac to the audience. But slides of the previous talks are now beginning to be available here<\/a>.<\/p>\n

Update<\/strong>: After looking through the slides of the talks and hearing a few of them, the thing that strikes me most about Strings 2008 is how little there has been about strings. Particle theory may be moving to a model where the big annual conference is labeled “STRINGS”, and speakers make nods of respect toward string theory, but actually talk about something else.<\/p>\n

The three big hot topics of the conference are <\/p>\n

  • the LHC (talks by Evans, Engelen and Buchmuller), which has nothing at all to do with string theory<\/li>\n
  • New 3d superconformal quantum field theories (talks by Lambert, Maldacena and Mukhi). One motivation for these is that they can be fit into a pattern of dualities, much like the famous 4d superconformal theories that have dominated particle theory research since Maldacena.<\/li>\n
  • Scattering amplitudes, especially those of N=4 SYM and N=8 supergravity (talks by Veneziano, Kallosh, Dixon, Cachazo, Green, Sokatchev and, to come, Alday). Some of this looks a lot like particle physics from the mid-60s, based on the study of the analytic S-matrix, including the presence of Veneziano. While there has been a lot of progress in studying certain kinds of QFT S-matrix amplitudes in recent years, some of it coming out of string theory, the most dramatic news is that about the possible finiteness of perturbative N=8 supergravity. Remember all those talks you’ve heard where someone draws a Feynman diagram and a string diagram, then explains how this shows that perturbative QFT has deadly divergence problems due to point-like interactions, while perturbative string theory doesn’t? Well, it appears that you can forget about all that now. In a rear-guard action, some speakers point out that you need to understand non-perturbative N=8 supergravity, and maybe this can’t be done in a QFT context. Unclear why non-perturbative string theory is supposed to help here, since the only viable non-perturbative version of it is, by duality, a QFT itself…<\/li>\n

    Looking at the talks that actually are about string theory unification, you quickly see why most people are talking about something else. Ibanez starts off by asking whether string theory makes physical predictions, then claims that it does, with one of them being exactly the reason it doesn’t make predictions about physics: “There is a large landscape of string vacuum solutions…”, which he then goes on to describe. Donagi’s talk, about Heterotic Standard Models, was remarkable in how much the situation there hasn’t changed since 1985. You can come up with such models with the right quantum numbers (and actually, just about any quantum numbers you want…), but to get anything else, you have to address how to stabilize moduli and break supersymmetry, and Donagi just mentions these problems at the end as tasks to address in the future. For more about the F-theory-motivated models reported on, see the comments at this posting<\/a>, where “anonymous” has an informed discussion with him (or her)self.<\/p>\n","protected":false},"excerpt":{"rendered":"

    Strings 2008 starts tomorrow at CERN, with about 400 physicists in attendance. CERN will be providing a live webcast for the rest of us. The timetable of the talks is here. The first afternoon will be devoted not to string … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[20],"tags":[],"class_list":["post-798","post","type-post","status-publish","format-standard","hentry","category-strings-2xxx"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/798","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=798"}],"version-history":[{"count":10,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/798\/revisions"}],"predecessor-version":[{"id":4930,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/798\/revisions\/4930"}],"wp:attachment":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=798"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=798"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=798"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}