tag:blogger.com,1999:blog-8666091.post1522362435217370591..comments2021-07-18T19:54:06.055+02:00Comments on The Reference Frame: Conformal Standard Model and the second \(325\GeV\) Higgs bosonLuboš Motlhttp://www.blogger.com/profile/17487263983247488359noreply@blogger.comBlogger12125tag:blogger.com,1999:blog-8666091.post-2529895179269855512013-03-04T06:49:00.915+01:002013-03-04T06:49:00.915+01:00Hi, it's just a less sophisticated cousin of &...Hi, it's just a less sophisticated cousin of "asymptotic safety" (because the author of your papers isn't quite a Steven Weinberg)<br /><br />http://motls.blogspot.cz/2009/07/cern-weinberg-about-asymptotic-safety.html?m=1<br /><br />http://motls.blogspot.cz/2010/06/asymptotic-darkness-vs-safety-and-non.html?m=1<br /><br />which is itself incompatible with basic properties of quantum gravity such as the dominance of ever larger black holes as microstates of high mass, and their entropy scaling. One may try to find a role for conformal gravity in various contexts but in ordinary nearly flat space we know, conformal gravity can be a good approximation neither at very high energies nor at very low energies which makes it unlikely that our world could in any sense be a "broken phase" of such a theory.Luboš Motlhttp://motls.blogspot.com/noreply@blogger.comtag:blogger.com,1999:blog-8666091.post-73161808657470931452013-03-04T05:08:27.796+01:002013-03-04T05:08:27.796+01:00Except it is possible a conformal gravity.
What do...Except it is possible a conformal gravity.<br />What do you think about it? It pretends to explain dark energy, dark matter, and is renormalizable. It is compatible with a Higgs conformal theory. <br />The idea is to take an action based on the weyl tensor.<br /><br />http://arxiv.org/abs/1101.2186<br />http://arxiv.org/abs/1208.4972<br />http://arxiv.org/abs/0707.2283Alan Givréhttp://www.facebook.com/alan.givrenoreply@blogger.comtag:blogger.com,1999:blog-8666091.post-19256415669497744792013-03-04T04:07:51.663+01:002013-03-04T04:07:51.663+01:00Unless you believe a conformal gravity is possible...Unless you believe a conformal gravity is possible. I don't understand them very well, but try these papers:<br />http://arxiv.org/abs/0707.2283<br />http://arxiv.org/abs/1101.2186<br />http://arxiv.org/abs/1208.4972<br />Tell me what you think.<br />The ideas seem interesting enough, I'd like to know your oppinion.<br />My mail is agivre@hotmail.comAlan Givréhttp://www.facebook.com/alan.givrenoreply@blogger.comtag:blogger.com,1999:blog-8666091.post-43478723280476593912012-08-31T03:00:06.653+02:002012-08-31T03:00:06.653+02:00Dear Lubos,
I found this discussion on your blo...Dear Lubos, <br /><br /><br />I found this discussion on your blog on the subject which I have been also working for quite of some time. Concerning the original MN paper I would like to point out that it is technically incorrect. The CW potential there is plugged by the large log problem. This is the same problem you account for in pure \phi^4 theory, and it has been known since the pioneering paper by Coleman & Weinberg. So, MN computations seems to be unreliable. In the simplest models like that you typically account Landau poles much below the Planck mass, if you do computations correctly (see, e.g. our paper 0704.1165).Archilnoreply@blogger.comtag:blogger.com,1999:blog-8666091.post-75348050002419812772012-08-30T01:08:41.411+02:002012-08-30T01:08:41.411+02:00Dear Lubos,
I found this discussion on your blo...Dear Lubos, <br /><br /><br />I found this discussion on your blog on the subject which I have also studied for quite some time. The point about the MN original paper is that it is technically incorrect, as their CW potential is plugged by the problem of large logs. This problem is the same problem one accounts in pure $\phi^4$ theory, and it has been discussed in the classic paper by Coleman & Weinberg. So, it is not entirely clear whether their calculations are reliable. In the simplest models like the MN model you typically end up with the Landau pole at energies much below the Planck mass, if you do proper computations (see, e.g. our paper arXiv:0704.1165)Archilnoreply@blogger.comtag:blogger.com,1999:blog-8666091.post-57272725094822437752012-08-29T19:07:29.496+02:002012-08-29T19:07:29.496+02:00Thanks Lumo for this enlightening answer :-)Thanks Lumo for this enlightening answer :-)Dilatonnoreply@blogger.comtag:blogger.com,1999:blog-8666091.post-16561802428061574142012-08-29T17:30:21.203+02:002012-08-29T17:30:21.203+02:00Yes, it's an idea independent of SUSY but of c...Yes, it's an idea independent of SUSY but of course, the parts of the overall theory that are relevant up to lower energy scales are the "more important ones" in phenomenology, so if the Conformal Standard Model were right and applied to a 325 GeV scalar boson, and SUSY were higher, SUSY would be irrelevant.<br /><br /><br />When I say "they're independent", it's about the list of possibilities only. Of course that SUSY would change the detailed RG running and everything would have to be redone if there were also extra fields.<br /><br /><br />Note that the "splitting of the roles" between the two Higgses is different in MSSM and different in the Conformal Standard Model so one could need 4 Higgs doublets in a combined "conformal MSSM". I am not going to work on these combined theories because already Conformal Standard Model looks like a stretch to me, see my reply to Dilaton.Luboš Motlhttp://motls.blogspot.com/noreply@blogger.comtag:blogger.com,1999:blog-8666091.post-34806774944315568932012-08-29T17:22:18.828+02:002012-08-29T17:22:18.828+02:00Dear Dilaton, good questions. Well, the hierarchy ...Dear Dilaton, good questions. Well, the hierarchy problem is just 1 reason among 5-10 major reasons why people like me believe in SUSY preserved well below the Planck scale. There's no strict proof that SUSY plays all the roles tthat it could play according to the "most SUSY-dominated" description of physics. I am almost totally ready to believe that there's a different logic that is important to explain why the Higgs is so light. But even if it is so, I still see lots of other reasons why SUSY is preserved up to scales that are much closer to the LHC scale than the Planck scale.<br /><br /><br />The model by Meissner and Nicolai is fun as an "isolated idea" trying to solve an "isolated problem" but there are lots of reasons why I don't really believe it's possible or it's the right logic at all if you consider all of physics. The adjustment of the field content to avoid the Landau pole seems kind of ad hoc but I have a more conceptual reason why I think that the very philosophy is unsustainable in the big picture. They demand the classical Lagrangian of the effective field theory to be scale-invariant. But we know that the total one is not: there is the Einstein-Hilbert action, S = integral R/16.pi.G, suppressed by the dimensionful Newton's constant i.e. associated with the Planck scale. So when one considers the effective action at the Planck scale, the dimensionful constants are inevitably there and the same Planckian physical phenomena are now free and eager to produce lots of other terms with dimensionful coefficients, too.<br /><br /><br />The idea that the conformal invariance holds "classically" requires one to deny the existence of gravity and that's too strong a denial for me. ;-)Luboš Motlhttp://motls.blogspot.com/noreply@blogger.comtag:blogger.com,1999:blog-8666091.post-67184162571718230592012-08-29T16:20:24.832+02:002012-08-29T16:20:24.832+02:00In the same vein as Dilaton, does this allow super...In the same vein as Dilaton, does this allow supersymmetry breaking at a higher energy scale, above or below the GUT scale, for a larger QFT?Physics Junkienoreply@blogger.comtag:blogger.com,1999:blog-8666091.post-50517253893850081242012-08-29T15:32:08.584+02:002012-08-29T15:32:08.584+02:00Hi! I think the bump will go away, especially beca...Hi! I think the bump will go away, especially because it should already be there at the LHC as well if real, but if it doesn't go away, yes, I would bet on MSSM.<br /><br /><br />Tom's paper expresses ideas he has believed for many years. I think that the existence of a larger number of solutions to string theory has been pretty much established; I think that the character and classification of all transitions between them isn't completely understood and some widely believed transitions could be forbidden while other unknown transitions could exist; while Tom's claims are therefore right in spirit, I don't believe in his superstrict segregation of the landscape to individual vacua.<br /><br /><br />He would probably need to convince one of the Calabi-Yau etc. professionals to co-write a paper with some convincing maths - before he would convince me. Incidentally, if the swampland-like ideas could exclude new slow-roll inflation and Tom were right about his ban on the landscape interpretation, string theory could easily ban inflation of all known types. I don't really believe it can be the case so at most one of the bans is likely and the ban on the slow-roll condition seems much more justified to me than Tom's ban on CDL-like tunneling on the landscape etc.<br /><br /><br />However, there are many "more abstract" aspects of this stuff where Tom could be importantly wrong, like the illegitimacy of talking about the degrees of freedom inside and outside an eternal-inflation decaying universe at the same moment. I am not using his precise words but I think this is one of the things he also believes. The space and therefore time on both sides is "qualitatively different" and complementarity etc. could prohibit double counting etc. etc.<br /><br /><br />All the best, <br />LMLuboš Motlhttp://motls.blogspot.com/noreply@blogger.comtag:blogger.com,1999:blog-8666091.post-51433609168141384192012-08-29T14:19:39.012+02:002012-08-29T14:19:39.012+02:00If this 325 GeV signal survives, would you bet on ...If this 325 GeV signal survives, would you bet on the supersymmetric explanation?<br /><br />On another note, what do you think of Tom Banks's new paper?<br />http://arxiv.org/pdf/1208.5715.pdfSynchronizenoreply@blogger.comtag:blogger.com,1999:blog-8666091.post-51074415405514310022012-08-29T13:17:52.421+02:002012-08-29T13:17:52.421+02:00Thanks Lumo for the interesting (and even to me no...Thanks Lumo for the interesting (and even to me not completely inaccessible) discussion of this "competitor" of the MSSM :-)<br /><br />If this were realized in nature and the updates work as expected, would this model make SUSY dispensible up to the Planck scale (at most) only? How (if at all) is it related to higher energy physics at scales where quantum gravity kicks in? Can it be derived as an effective QFT from higher energy physics in a similar way as it can be done for the MSSM ? Does it contradict String theory.<br /><br />No I've bombarded you with enough potentially stupid questions ... :-P<br />I mean no harm by it but I am confused about what implications (if any) this model would have for the "broader picture" of fundamental physics.Dilatonnoreply@blogger.com