tag:blogger.com,1999:blog-22973357.post6804398251661694458..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: Loops and Strings and StuffSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger11125tag:blogger.com,1999:blog-22973357.post-30899726941117579072016-01-21T03:24:42.994-05:002016-01-21T03:24:42.994-05:00"No, because this doesn’t actually tell you a..."No, because this doesn’t actually tell you anything specific about the UV completion, except that it must have a well-behaved type of non-local interaction that Loop Quantum Gravity doesn’t seem to bring, or at least it isn’t presently understood how it would."<br /><br />I have always understood that non-locality is a fundamental part of LQG because in LQG locality is an emergent andrewhttps://www.blogger.com/profile/08172964121659914379noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-26662590674551777132015-09-03T00:14:40.608-04:002015-09-03T00:14:40.608-04:00A good testing ground would be to map the puncture...A good testing ground would be to map the punctured black hole horizon in LQG to brane configurations in string theory. Punctures would be mapped to branes, and short strings connect each brane (puncture). The geometry is initially noncommutative, as the brane configuration is described by a Hermitian element of a C*-algebra. The eigenstates of the Hermitian operator correspond to the branes, Metatronhttps://www.blogger.com/profile/08396427736998362077noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-896126137329890462015-09-02T05:18:50.942-04:002015-09-02T05:18:50.942-04:00Then tell me a) how the translation operator acts ...Then tell me a) how the translation operator acts on position eigenstates and b) what is the sum of two momenta. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-63297897820013072802015-09-02T03:38:42.156-04:002015-09-02T03:38:42.156-04:00As far as I know it does not.As far as I know it does not.Jerzyhttps://www.blogger.com/profile/14391724377369641268noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-38584195147150665782015-09-02T02:19:19.876-04:002015-09-02T02:19:19.876-04:00Because, as I think you know, it leads to macrosco...Because, as I think you know, it leads to macroscopic non-localities and problems with the construction of multi-particle states, both of which is in conflict with observation.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-68614203680819210002015-09-02T02:03:45.538-04:002015-09-02T02:03:45.538-04:00"you get yourself into deep shit" Hm... ..."you get yourself into deep shit" Hm... Interesting ... Why?Jerzyhttps://www.blogger.com/profile/14391724377369641268noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-7829683531382321122015-09-01T18:08:14.320-04:002015-09-01T18:08:14.320-04:00String theory and Loop quantum gravity both have a...String theory and Loop quantum gravity both have another huge feature that brings them together: They both don't work, and in all likelihood never will. The amount of hours poured into these two theories is likely 10x all hours spent on all theoretical physics prior to 1950. <br /><br />I argue that we have worked those directions rather exhaustively. Its time for something completely Tom Andersenhttps://www.blogger.com/profile/17562906116020498110noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-20772388335588130152015-09-01T11:49:44.137-04:002015-09-01T11:49:44.137-04:00Uncle,
Thanks, fixed that. I originally wrote &qu...Uncle,<br /><br />Thanks, fixed that. I originally wrote "big trouble," and ended up with a semi-shittical sentence ;) Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-4227512151091653082015-09-01T11:25:14.891-04:002015-09-01T11:25:14.891-04:00"get yourself into big..." "deep&qu..."<i>get yourself into big...</i>" "deep" here. Parameterize, <br />http://www.urbandictionary.com/define.php?term=Deep+Kimchi<br /> deep kimchi<br /><br />"<i>violation of Lorentz-invariance in the matter sector would be in conflict with experiment, so that can't be correct</i>" Run an experiment external to physics' postulates demanding Lorentz / Uncle Alhttps://www.blogger.com/profile/05056804084187606211noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-37491765196935417022015-09-01T10:17:03.221-04:002015-09-01T10:17:03.221-04:00Yes. When it comes to Lagrangians all that "n...Yes. When it comes to Lagrangians all that "non-local" really means is that they have higher-order terms, and these can perfectly well be Lorentz-invariant. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-25995650324646753592015-09-01T10:07:57.087-04:002015-09-01T10:07:57.087-04:00Hi Bee,
Are there *non-local* Lagrangians which do...Hi Bee,<br />Are there *non-local* Lagrangians which do not violate Lorentz invariance?kashyap vasavadahttps://www.blogger.com/profile/10732897306667764590noreply@blogger.com