tag:blogger.com,1999:blog-2846514233477399562.post8861048838092699283..comments2024-01-08T09:37:04.406+01:00Comments on RÉSONAANCES: Weekend Plot: flexing biceps Jesterhttp://www.blogger.com/profile/08947218566941608850noreply@blogger.comBlogger34125tag:blogger.com,1999:blog-2846514233477399562.post-10546478291878128502014-03-18T02:14:37.257+01:002014-03-18T02:14:37.257+01:00This comment has been removed by the author.andrewhttps://www.blogger.com/profile/08172964121659914379noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-73866399442938663662014-03-18T02:14:35.445+01:002014-03-18T02:14:35.445+01:00"they find a best-fit value of the scalar-ten..."they find a best-fit value of the scalar-tensor ratio of r = 0.20 +0.07/-0.05,"<br /><br />See 16 March 2014 05:15andrewhttps://www.blogger.com/profile/08172964121659914379noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-43164385658457887922014-03-17T17:04:27.504+01:002014-03-17T17:04:27.504+01:00Looks like the rumor was right (they have a non-ze...Looks like the rumor was right (they have a non-zero tensor to scalar ratio, 0.20 with ~1/3 of this value as uncertainty), but the website is unavailable now - probably due to the load.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-19447697150260826022014-03-17T14:56:31.234+01:002014-03-17T14:56:31.234+01:00I would say that this rumored result, if correct, ...I would say that this rumored result, if correct, would be a much more direct detection of gravitational waves than for the Hulse-Taylor system. (In fact, the mechanism here is not so different from that used in interferometers: it's the primordial matter which serves as test masses.) The issue as far as gravity waves go is not so much indirectness as the problem of eliminating possible confounding effects.Adam Helfernoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-29538132848217246612014-03-17T07:17:23.394+01:002014-03-17T07:17:23.394+01:00deep throatdeep throatJesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-12997156598904163592014-03-17T07:17:22.941+01:002014-03-17T07:17:22.941+01:00deep throatdeep throatJesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-66719993571152526822014-03-16T22:16:53.985+01:002014-03-16T22:16:53.985+01:00"It's certain it's going to be an ann..."It's certain it's going to be an announcement by BICEP"<br /><br />Again...who's certain? Where did the information that it's going to be a BICEP announcement come from?asadnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-50022173201663757982014-03-16T19:34:38.769+01:002014-03-16T19:34:38.769+01:00Anonymous: " ...just within 3 Months of their...Anonymous: " ...just within 3 Months of their publication in January ..." That was BICEP1 = zero with big error bars. This is BICEP2Philip Gibbshttp://blog.vixra.org/noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-51313972089917439842014-03-16T18:20:08.760+01:002014-03-16T18:20:08.760+01:00Large "r" does not mean Large VEV inflat...Large "r" does not mean Large VEV inflation, Sesh himself worked on with Hotchkiss - a possibility of large 'r' with small VEVs - or Sub-Planckian VEV inflation.Anupamnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-7842355625559338562014-03-16T18:04:27.220+01:002014-03-16T18:04:27.220+01:00Thanks. I thought you were referring to natural un...Thanks. I thought you were referring to natural units,just wanted to make sure.Ervin Goldfainhttps://www.blogger.com/profile/07585008304556273617noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-18045431839766886312014-03-16T18:00:22.173+01:002014-03-16T18:00:22.173+01:00To comment on my comment before: reading into Sesh...To comment on my comment before: reading into Sesh's post he says that the large tensor-to-scalar ratio more generally disfavors all small-field inflation models. That's interesting, I need to read more about this. Jesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-23063840294354984822014-03-16T17:46:39.553+01:002014-03-16T17:46:39.553+01:00Ervin, the inflaton potential in the Lagrangian h...Ervin, the inflaton potential in the Lagrangian has units [Energy]^4 (in the only legitimate unit system where c=hbar=1). BICEP says V~\rho~(2*10^16~GeV)^4 Jesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-57271231165555381172014-03-16T17:09:18.529+01:002014-03-16T17:09:18.529+01:00April fool's day - even before April 1st. The ...April fool's day - even before April 1st. The cosmology community is soooo desperate to get some solace from the data after the Planck - No-primordial-non-gaussianity..<br /><br />I do not think there is any iota of reasons to believe Bicep will release any data and improve the data just within 3 Months of their publication in January ( where they quoted B-mode consistent with zero), http://iopscience.iop.org/0004-637X/783/2/67/pdf/apj_783_2_67.pdf<br /><br />Forget B modes, there could be a new discovery of a worm hole, new aliens wants to do chit-chat with the Planetary beings.., there could many major discoveries on card..Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-60807739270262256742014-03-16T16:29:48.253+01:002014-03-16T16:29:48.253+01:00What system of units do you use when talking about...What system of units do you use when talking about the inflation energy density measured in GeV?Ervin Goldfainhttps://www.blogger.com/profile/07585008304556273617noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-31890103100170693462014-03-16T16:09:53.321+01:002014-03-16T16:09:53.321+01:00I'm not sure if the point about trans-Planckia...I'm not sure if the point about trans-Planckian values is new; we knew before BICEP, or even before Planck, that in single-field inflation we need trans-Planckian inflaton vev to ensure slow-roll conditions. Now, it's true that BICEP only tells us the energy density during inflation is 10^16 GeV, not that the inflaton mass is 10^16 GeV. Jesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-30863433057642462662014-03-16T10:16:10.927+01:002014-03-16T10:16:10.927+01:00Andrew, I sort of doubt that they would use the wo...Andrew, I sort of doubt that they would use the word "major discovery" if the signal were just 3 sigma. I think that people underestimate BICEP2's sensitivity and also the time they have spent. It's been running almost for 5 years or something like that. They may still be wrong for some reason but it is utterly unfair to call their presentation "premature" etc.Luboš Motlhttps://www.blogger.com/profile/17487263983247488359noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-56025015466317240942014-03-16T08:15:13.603+01:002014-03-16T08:15:13.603+01:00Hi Jester, At his blog Sesh mentions that the rum...Hi Jester, At his blog Sesh mentions that the rumored result would mean that the inflation field \phi takes values larger than the Planck scale. If so, can we conclude that the discovery would imply some new physics between weak and Planck scales as you have done?<br /><br />Sesh says that while the "energy scale" is always less than the Planck scale, the field value for \phi is above Planck scale for r=0.2.<br /><br />Sesh's blog is at http://blankonthemap.blogspot.co.uk/2014/03/b-modes-rumours-and-inflation.htmlAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-11243065988819654562014-03-16T05:15:39.825+01:002014-03-16T05:15:39.825+01:00A result of r=0.20 +/- 0.07 plus or minus 0.01 in ...A result of r=0.20 +/- 0.07 plus or minus 0.01 in either number, gives rise to an almost 3 sigma signal of some non-zero value of r, would have a two sigma confidence interval that would overlap with the Planck data. "Proof that gravitational waves exist" is a pretty good way to popularize a finding that r>0 even if your MOE is too large to say much more than that.<br /><br />This high end result for the central value would, when viewed together with the current Plank data in light of the high margin of error of the result, tend to favor scenarios (with the other parameter being at a best fit 0.97 value from the existing data) such as a r that is exactly on the concave/convex boundary (i.e. flat, which nicely complements the overall topology of space-time seen in CMB data) and also "natural inflation" scenarios, while disfavoring very simple Higgs inflation models motivated by apparently very low r values seen so far.<br /><br />Why would BICEP be so hot to trot on a result that might very well be less than 3 sigma and hasn't had time to be carefully reconfirmed?<br /><br />BICEP needs to scoop the Planck polarization data to be relevant. The Planck polarization data is due to be released in a matter of weeks and will probably confirm the BICEP result at an unknown but sub-5 sigma level.<br /><br />Waiting until it has enough data to report a 3-4 sigma result and fudging close judgment calls in analysis in favor of a higher result with a higher margin of error, rather than holding out for a low margin of error and the same level of confidence in the result, means letting your find be simply a confirmation of the Planck polarization data result with slightly different central and MOE values. This doesn't win prizes or grants the way that being the first experiment to show strong, sub-discovery evidence of a non-zero value for r does.andrewhttps://www.blogger.com/profile/08172964121659914379noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-91033504101011890052014-03-15T21:43:48.268+01:002014-03-15T21:43:48.268+01:00True. I modified that sentence to make it more cle...True. I modified that sentence to make it more clear. Jesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-33701271348031670992014-03-15T20:04:43.886+01:002014-03-15T20:04:43.886+01:00Just a minor point -- the B-mode actually results ...Just a minor point -- the B-mode actually results from the action of the gravitational wave (metric fluctuation) *AT* the last-scattering surface. Although the wave is generated by quantum fluctuations during the inflationary epoch, it propagates unimpeded and shakes the plasma. When decoupling happens, CMB polarization (E and B modes) are generated.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-74075544823980046552014-03-15T15:56:27.110+01:002014-03-15T15:56:27.110+01:00For slow-roll inflation you can solve for V and V&...For slow-roll inflation you can solve for V and V' knowing As, and r, see e.g. Eqs. 13-14 in the Planck paper 1303.5082.Jesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-62548712350086316662014-03-15T13:31:05.420+01:002014-03-15T13:31:05.420+01:00Jester thanks for your note. How do you get the s...Jester thanks for your note. How do you get the scale 2 x 10^16 GeV? Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-82336454183220263272014-03-15T01:26:11.718+01:002014-03-15T01:26:11.718+01:00Thanks Adam, I thought so.
Many believe (myself i...Thanks Adam, I thought so.<br /><br />Many believe (myself included) that the desert hypothesis is likely wrong for many reasons.Ervin Goldfainhttps://www.blogger.com/profile/07585008304556273617noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-79566593489719517432014-03-15T01:09:56.858+01:002014-03-15T01:09:56.858+01:00
Could the same analytical methods be used for rea...<br />Could the same analytical methods be used for reading tea leaves?Robert L. Oldershawhttps://www.blogger.com/profile/15396555790655312393noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-54402430657132587002014-03-15T01:05:21.083+01:002014-03-15T01:05:21.083+01:00"This would be the first direct evidence for ..."This would be the first direct evidence for a new particle physics scale between the electroweak and the Planck scales"<br /><br />What about gravity? Isn´t that a truly BSM new physics scale?Anonymousnoreply@blogger.com