tag:blogger.com,1999:blog-22973357.post6335379116400983649..comments2016-06-30T00:35:28.886-04:00Comments on Backreaction: A Theoretically Simple Exception of EverythingSabine Hossenfelderhttps://plus.google.com/111136225362929878171noreply@blogger.comBlogger284125tag:blogger.com,1999:blog-22973357.post-89103145806703802432007-11-16T18:13:00.001-05:002007-11-16T18:13:00.001-05:00Hi AllIt seems the discussion to this thread has r...<B>Hi All</B><BR/><BR/>It seems the discussion to this thread has reached the blog recurrance length. People have started to comment without reading the previous exchanges (or the post to begin with). Questions, answers, arguments and criticism on both sides have been repeated several times. <BR/><BR/>I see no point on continuing the discussion under these circumstances, and therefore I will close the comment section. <BR/><BR/>We might have a follow up posting in the next weeks, summarizing this thread, and opening a possibility to continue the discussion for those who are still interested.<BR/><BR/>Thanks to everybody for your contributions, it has been very interesting.<BR/><BR/>Best,<BR/><BR/>B.Beehttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-76373487367824905492007-11-16T18:13:00.000-05:002007-11-16T18:13:00.000-05:00So long, and thanks for all the fish.So long, and thanks for all the fish.garretthttp://www.blogger.com/profile/03136765358626033631noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-78909836218093178782007-11-16T17:57:00.000-05:002007-11-16T17:57:00.000-05:00hi friendly moderator,could you please enlighten u...hi friendly moderator,<BR/><BR/>could you please enlighten us about why we have to stop discussing? has the pope put out a bull and we will be under his ban-ray if we continue enjoying ourselves here?chrisnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-3156826167445720812007-11-16T17:56:00.000-05:002007-11-16T17:56:00.000-05:00observer telling your friendly moderator to post u...observer telling your friendly moderator to post under a real name? Haha!<BR/><BR/>The bold text was a quote from Bee in case anyone hasn't read the previous comments.Your Friendly Moderatornoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-33162663830582391272007-11-16T17:44:00.000-05:002007-11-16T17:44:00.000-05:00"How can I possibly say that clearer" By posting u..."How can I possibly say that clearer" By posting under your own name, perhaps, instead of pretending that it's up to you to moderate someone else's blog.Observernoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-430144142056389462007-11-16T17:38:00.000-05:002007-11-16T17:38:00.000-05:00How can I possibly say that clearer: Given today's...<B>How can I possibly say that clearer: Given today's status, Garrett's model does *not* naturally lead to a unification of the SM interactions with gravity (he has to chose the action by hand that contains both), it does *not* allow us to understand quantum gravity (since there's nothing said about quantization), it does *not* explain the parameters in the SM (since there isn't yet a mechanism for symmetry breaking), it does *not* explain the cosmological constant or its value (as said above, to claim there has to be one, it would be necessary to show there's no way to do it without one), it does *not* explain the hierarchy problem (and I see no way to do so), it does *not* explain why we live in a spacetime with 3 spatial and 1 timelike dimensions, it does *not* in my very humble opinion yet qualify being called a Theory of Everything.</B><BR/><BR/>At this point, I think this thread should be closed. I strongly recommend the blog owner to do so. While it may be obvious to the paper's author about how this all is covered, the paper obviously needs more authoring.Your Friendly Moderatornoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-5664335913219928692007-11-16T17:19:00.000-05:002007-11-16T17:19:00.000-05:00hi amused,i am not here to defend garretts theory....hi amused,<BR/><BR/>i am not here to defend garretts theory. but *if* you swallow that his theory contains this gauge fixing term that effectively comes from dynamics at higher scales, then you evade C-M at low scales by not violating it and at high scales by not being locally isomorphic to the lorentz group (above m_planck, which i guess would be close to m_lisi :-), i do not expect minkovski space to be a good approximation anymore, no?)<BR/><BR/>the big mystery to me is how you would get an effective gauge fixing term.chrisnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-8318357636789356102007-11-16T17:12:00.000-05:002007-11-16T17:12:00.000-05:00hi bee,by effective theory i mean, that a gauge fi...hi bee,<BR/><BR/>by effective theory i mean, that a gauge fixing term in the lagrangean can hardly be accepted as god-given (or nature given if you happen to be atheist :-)). garrett also said so in a previous post, so i guess this is his take on it, too. so there should be some dynamics (at some higher scale i suppose?) to provide this term.<BR/><BR/>as i said, i have no idea if this makes any sense.chrisnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-62340490652814213522007-11-16T17:02:00.000-05:002007-11-16T17:02:00.000-05:00gear garrett, it is none of my business whether yo...gear garrett,<BR/><BR/> it is none of my business whether you decide to submit your paper to a journal, but i would like to respond to your very broad assertion of the brokenness of the peer review process.<BR/><BR/>up front: yes, i think it is broken in some ways. i do not want to indulge further, but basically all the brokenness is due to many papers being "under the radar" and therefore exposed to subjective treatment by sometimes a single referee. that can be harsh and everything, but ultimately, i don't know of any good papers in my field that didn't take that hurdle.<BR/><BR/>in your case, given the ongoing media attention, your paper is certainly on the radar. i guess that every serious journal would be well advised to treat your paper very carefully and properly, so i really think that you need not worry about ill treatment there. in fact, what is happening here is already kind of a peer review. and as you can see the spectrum of reactions is quite broad.<BR/><BR/>it is of course your choice and in the end we will see, if the paper gets cited or not. but let me just tell you that for most of us the peer review is nothing else than putting your money where your mouth is. if what you say is correct and relevant and if you welcome honest and serious critique, there should be nothing to fear.chrisnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-52369760325167840472007-11-16T16:50:00.000-05:002007-11-16T16:50:00.000-05:00A present for Dr Lisi from the cheap seats: http:/...A present for Dr Lisi from the cheap seats: http://uncyclopedia.org/wiki/UnNews:Surfer_dude_stuns_physicists_with_theory_of_everythingDavid Gerardhttp://www.blogger.com/profile/13057086390864018760noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-35890971581438806282007-11-16T16:35:00.000-05:002007-11-16T16:35:00.000-05:00chris,If the action in the paper is obtained throu...chris,<BR/><BR/>If the action in the paper is obtained through gauge fixing then the C-M considerations can be applied to the original, unfixed action (whatever that is). The physics is independent of the choice of gauge fixing, presumably. So I would expect the C-M considerations to still hold. <BR/><BR/>Garrett,<BR/><BR/>"Please answer for me: which other part of the so(7,1)+so(8)subalgebra of the e8 Lie algebra is it that the so(3,1) doesn't commute with -- given the way I've broken it up?"<BR/><BR/>As Bee already mentioned, E8 is not the direct product of SO(3,1) with something. That's the relevant point for the C-M stuff.amusednoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-89285334334984720992007-11-16T16:31:00.000-05:002007-11-16T16:31:00.000-05:00Chris: Yes, thanks. I just wanted to make that cle...Chris: Yes, thanks. I just wanted to make that clear, once again, that's one of the reason why things work out, and it doesn't arise from the E8 root diagram, there are a lot of extra assumptions that go in here. I am still not convinced though that the gauge fixing can be sufficient to make it work. In what sense do you mean 'effective theory'? If you are referring to the 'top down inspired bottom up' remark, please see the comments above. - BBeehttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-66469732067298514812007-11-16T16:20:00.000-05:002007-11-16T16:20:00.000-05:00hi bee,he has a gauge fixing term in his lagrangea...hi bee,<BR/><BR/>he has a gauge fixing term in his lagrangean. this is also how he can get 'ghosts' in the first place. and he repeatedly stated that this is done ad hoc. so as i get it, it really is just an effective theory, not the fundamental one and yes, certainly not a E8 gauge theory in the classical sense.chrisnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-38759282900623238002007-11-16T16:13:00.000-05:002007-11-16T16:13:00.000-05:00Wes, Jonathan,As I wrote in my postTo make predict...Wes, Jonathan,<BR/><BR/>As I wrote in my post<BR/><BR/><I>To make predictions with this model, one first needs to find a mechanism for symmetry breaking which is likely to become very involved.</I><BR/><BR/>Further, there is the very general observation<BR/><BR/><I>He finds a few additional particles that are new, which are colored scalar fields.</I><BR/><BR/>Given that these couple strongly, their masses have (as usual) to be so high as to not yet have been observed, but maybe potientially LHC testable. <BR/>Best,<BR/><BR/>B.Beehttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-21868122156424274132007-11-16T16:08:00.000-05:002007-11-16T16:08:00.000-05:00Wes,I agree that I'd like to see a discussion of t...Wes,<BR/>I agree that I'd like to see a discussion of this. As an engineer, to me the old adage regarding the relative weights of theory and evidence is always the guiding light of these things -- no matter how elegant the theory.Jonathannoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-77539975586641843822007-11-16T16:05:00.000-05:002007-11-16T16:05:00.000-05:00Having read the entire blog (yes), I'm struck that...Having read the entire blog (yes), I'm struck that so far there have been no comments about the predictions that could be made from this theory. My question to those of you who best understand this are:<BR/><BR/>1) What are the predictions that this theory can make that are most likely to be tested first.<BR/><BR/>2) For those of you that so strongly argue that the theory is flawed, does it predict something testable now that could be used to disprove the theory quickly?<BR/><BR/>ThanksWeshttp://www.blogger.com/profile/16028341084563018645noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-50949811282177277352007-11-16T16:01:00.000-05:002007-11-16T16:01:00.000-05:00Hi Garrett: Thanks. So your above comment again re...Hi Garrett: Thanks. So your above comment again referred to after the symmetry breaking, but they do mix before the symmetry breaking? Sorry for repeating that, I just think there are still people who haven't understood that you are not just doing E8 gauge theory, but fix these details by hand.<BR/><BR/>Everybody: would you please, please do me the favor to read the comments and the post above before you reiterate part of the discussion? <BR/><BR/>Best, B.Beehttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-37161627084374618412007-11-16T15:53:00.000-05:002007-11-16T15:53:00.000-05:00aaron and bee:There is no symmetry here that mixes...aaron and bee:<BR/>There is no symmetry here that mixes the Grassmann fields and gauge fields. Chris reiterated for me, and I will re-reiterate: the full e8 symmetry is broken (by hand) by the action.<BR/><BR/>Whew, two and a half with one stone. I have to go for a bit -- back later.garretthttp://www.blogger.com/profile/03136765358626033631noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-49928403524745813792007-11-16T15:49:00.000-05:002007-11-16T15:49:00.000-05:00Garrett, So when you write su(N) you are ref...Garrett,<BR/> So when you write su(N) you are referring to the adjoint representation of SU(N) rather than the gauge group SU(N)? So, su(4) = u(1) + su(3) + 3 + 3-bar is just the breakdown of the adoint of SU(4) after a symmetry breaking?Ericnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-47617881838034045762007-11-16T15:42:00.000-05:002007-11-16T15:42:00.000-05:00hi amused,garrett explicitly stated that his lagra...hi amused,<BR/><BR/>garrett explicitly stated that his lagrangean is explicitly a gauge fixed one, so no, it does not have E8 gauge symmetry all the way down even to the effective scale he writes his lagrangean.<BR/><BR/>if this makes sense - i honestly have no clue. but that is how he formulated it. so the point of the nontrivial SO(3,1) embedding could just be moot.chrisnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-35174118248552198872007-11-16T15:39:00.000-05:002007-11-16T15:39:00.000-05:00Garrett:The SM gauge transformations don't mix wit...Garrett:<BR/><BR/><I>The SM gauge transformations don't mix with the Lorentz transformation. For further clarification, have a look at the question I asked Amused. </I><BR/><BR/>Are you referring to this:<BR/><BR/><I>which other part of the so(7,1)+so(8) subalgebra of the e8 Lie algebra is it that the so(3,1) doesn't commute with -- given the way I've broken it up?</I><BR/><BR/>*sigh*<BR/><BR/>First, you said above they do mix (<I>"They all mix, and we fix that with the symmetry breaking."</I>). I thought I understood this, and tried to live with it. E8 is not a direct product of SO(3,1) with something. But isn't that what you need if you don't want them to mix? Best,<BR/><BR/>B.Beehttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-4441601601066451882007-11-16T15:35:00.000-05:002007-11-16T15:35:00.000-05:00That's confusing two different gradings. The best ...That's confusing two different gradings. The best example is the one-form in ordinary EM. It is a commuting field even though it is a one form, and to have a symmetry with a Grassman field, you need Grassman symmetry which is what is done in super-yang-mills.<BR/><BR/>Also, to be completely precise, you're not describing how the Lie algebra breaks up. What you are doing is describing how the adjoint representation decomposes when you pass to a subgroup.Aaron Bergmannoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-50822287426960515962007-11-16T15:20:00.000-05:002007-11-16T15:20:00.000-05:00eric:It's a description of how the Lie algebra bre...eric:<BR/>It's a description of how the Lie algebra breaks up.<BR/><BR/>bee:<BR/>The SM gauge transformations don't mix with the Lorentz transformation. For further clarification, have a look at the question I asked Amused. <BR/><BR/>aaron:<BR/>"You're transforming commuting fields into Grassman fields." No, I'm not. I'm replacing 1-forms, which anti-commute, with Grassmann fields.garretthttp://www.blogger.com/profile/03136765358626033631noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-48485495919212197402007-11-16T15:15:00.000-05:002007-11-16T15:15:00.000-05:00"for example in Journal of Asian Mathematics" he s..."for example in Journal of Asian Mathematics" he says, and points to a revised and renamed version of the original "<A HREF="http://news.xinhuanet.com/english/2006-06/03/content_4642313.htm" REL="nofollow">Chinese mathematicians prove the Poincare Conjecture!</A>" paper Cao/Zhu published in that journal; a paper that, according to some, caused Perelman to abandon mathematics. Now that's one broken process if I've ever seen one ;-)Observernoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-31860255881146673522007-11-16T15:10:00.000-05:002007-11-16T15:10:00.000-05:00eric:The lower case indicates these are Lie algebr...eric:<BR/>The lower case indicates these are Lie algebras. Throughout the paper, I'm working at the Lie algebra level. I haven't worked out this group breakdown on the global, topological level yet -- but that raises some fascinating and difficult questions.<BR/><BR/>amused:<BR/>Please answer for me: which other part of the so(7,1)+so(8) subalgebra of the e8 Lie algebra is it that the so(3,1) doesn't commute with -- given the way I've broken it up? I believe answering this will help in understanding this issue.garretthttp://www.blogger.com/profile/03136765358626033631noreply@blogger.com