The arguments couldn't have got been properly analyzed together with compared inward such a express context. In science, it is amend to write them down. You may aspect at these arguments together with equations for hours – together with hence tin your antagonists – which unremarkably increases the lineament of the analyses. Team Stanford clearly believes that the de Sitter vacua are hither to stay, the criticisms are wrong, together with quintessence has fatal problems. But tin they dorsum these opinions past times convincing arguments?
Today, inward the listing of new hep-th preprints, nosotros received an avalanche of papers that say something virtually the deSitter-vs-quintessence tilt inward string theory. Using the [numbers] from the daily ordering of papers, nosotros beak virtually the next papers:
[3] De Sitter vs Quintessence inward String Theory (by Cicoli+4, 49 pages)I have got omitted Tadashi Takayanagi's paper(s) although i of them also talks virtually de Sitter spaces.
[4] A comment on effective acre theories of flux vacua (by Kachru+Trivedi, 22 pages)
[15] dS Supergravity from 10d (by Kallosh+Wrase, eighteen pages)
[16] de Sitter Vacua alongside a Nilpotent Superfield (by Kallosh+3, vi pages)
[18] The landscape, the swampland together with the era of precision cosmology (by Akrami+3, 43 pages)
First, concerning the affiliations: I include all of the collaborations into "Team Stanford" because they defend de Sitter solutions inward string theory. But the commencement newspaper is genuinely international (Bologna-Boulder-India-Cambridge), the minute newspaper is Stanford-Bombay, the 3rd newspaper is Stanford-Vienna, the 4th newspaper is Stanford-Brown-Leuven (Belgium), together with the terminal newspaper is Stanford-Leiden (the Netherlands).
Well, yous may hopefully run across that Stanford is overrepresented inward these papers. Moreover, it seems to play the purpose of the "headquarters" of this campaign. And the commencement newspaper amid the v which is the entirely Stanford-free is arguably the to the lowest degree combative one, too. ;-) I mean value it's fair to say that the stringy landscape moving-picture demo of cosmology is the greatest rootage of pride for Stanford's theoretical physicists inward recent xv years. At some human level, nosotros could sympathise why they could live anxious if somebody were basically maxim that those xv years revolved unopen to a fault or some sloppiness. But the pride doesn't imply that those papers were correct together with safe, of course.
Now, the publish of papers – v – is rather large together with the salvos had to live at to the lowest degree partially coordinated. Can the colleagues live expected to swallow a reasonably high percent of the content? Wasn't the publish of papers chosen to live high to only intimidate the opposition? To supervene upon the lineament of the arguments alongside the quantity of papers? I am non maxim that. I am just asking. The high publish of papers leads me to similar feelings equally the proposed large publish of de Sitter vacua. Less is sometimes more.
Let's beak virtually the dissever papers. The middle paper, i past times Kallosh together with Wrase, claims that the anti-D3-branes inward the KKLT "uplifting" physical care for may live replaced past times anti D5, D6, D7, or D9-branes, too. That seems similar a bold declaration to me. If this were the case, why wouldn't have got KKLT noticed these 4 novel possible dimensions correct away? Fifteen years ago, I was for certain bespeak the enquiry why anti-D3-branes were used together with non some branes of other dimensions together with I was for certain given a – non hence convincing – reply implying that it had to live anti-D3-branes. If i says that 4 possible dimensionalities of the antibranes are just equally OK, together with i does hence xv years afterward the game-changing newspaper is released, it doesn't just assist both of these papers to live trustworthy.
I would likely select to disbelieve the novel Kallosh-Wrase paper. One full general occupation alongside this newspaper (but, to some extent, alongside many other papers together with perhaps alongside Team Stanford's papers inward general) is that it seems to live a supergravity paper, non a full-blown stringy paper. And I mean value it's fair to push clit both Kallosh together with Wrase equally supergravity experts, non string theory experts. Shouldn't a full-blown string theory proficient validate claims that D-branes may live used inward a sure novel way? My reply is that he or she should.
At their supergravity degree of analysis, many things are possible together with they may modify the dimensionality of the uplifting antibrane. Great. But have got they genuinely demonstrated that string theory allows such solutions, peculiarly the novel ones? I don't mean value that they have got made the full-blown string analysis. Whatever is intrinsically stringy is treated inward a sloppy way. For example, search for an "open string" inward the Kallosh-Wrase paper. You volition acquire 3 hits – together with all of them just say that they have got ignored the opened upward string moduli.
The to a greater extent than stringy a given concept or construction is, the to a greater extent than it is ignored inward this paper. Again, I mean value that this criticism applies to most of the Team Stanford papers inward general. But the whole indicate of the Vafa Team is to carefully report the fine, characteristically stringy features, phenomena, together with constraints that are completely invisible at the degree of supergravity – i.e. at the degree of effective acre theory. I have got doubts virtually every particular, precise plenty "swampland statement" made past times Vafa or whatever disciple (including our "weak gravity conjecture" group). On the other hand, I have got no doubts that it is extremely of import to appreciate that string theory is not just supergravity together with most of the particular low-energy supergravity-based effective acre theories have got no consistent quantum gravity or stringy completion.
Kallosh together with Wrase – and, equally I said, much of the Team Stanford – seem to exercise string theory equally the "ultimate justification of the 'anything goes' image inward supergravity". You may practise anything yous desire inward supergravity, add together whatever string-inspired object, fluxes, branes, whatever yous like, together with and then yous exercise the term "string theory" equally if it were the ultimate together with universal justification of the validity of all such constructions. For them, string theory is just a knife that ever unties your hands. Like alongside Elon Musk's promises, anything goes alongside string theory.
OK, I am sure that this is just a incorrect usage or interpretation of "string theory". String theory offers some novel tools, novel objects, novel transitions, phenomena, together with relationships betwixt the objects. But string theory also – together with maybe primarily – brings us novel constraints, novel bans, novel universal, together with particular predictions. For me, string theory may have got produced novel ingredients together with possibilities but it's all the same primarily a theory that has a greater predictive powerfulness than the effective quantum acre theory. It's clearly a sloppy, skewed agency to exercise string theory if somebody entirely uses string theory equally the "source of many novel objects together with possibilities" – together with non equally a "book total of novel constraints, universal laws together with principles, together with previously impossible predictions for particular situations".
(There has been a community of "extremely applied" string theorists – whom I would for certain telephone yell upward non-string theorists – who have got used the term "string theory" equally an excuse for genuinely non-standard pieces of physics including the Lorentz symmetry violation together with the violation of the equivalence principle. I believe that string theory is, on the contrary, a enterprise framework that bans or at to the lowest degree greatly discourages such experiments.)
Because nosotros are discussing the enquiry whether the carefully together with accurately studied string/M-theory allows de Sitter vacua, the KKLT construction, together with similar things, some other supergravity-level sloppy analysis just cannot perchance live relevant for the large enquiry defining the Team Stanford vs Team Vafa controversy. To resolve this controversy, i only needs a higher stringy precision of the arguments. The newspaper past times Kallosh together with Wrase doesn't have got it together with it's questionable whether they could brand such an analysis inward whatever other paper.
OK, let's immediately aspect at the 4th newspaper amid the v virtually a "nilpotent superfield". The novel newspaper is a response to a 2017 newspaper Towards de Sitter from 10D past times Moritz, Retolaza, together with Westphal. OK, those authors have got claimed that the KKLT didn't operate because during the uplift, at that spot was a stronger backreaction than previously idea together with the compactification remains AdS together with doesn't acquire dS. In the novel paper, they claim that the nilpotent superfield equally a SUSY breaking tool isn't compatible alongside the nonlinearly realized SUSY. But that doesn't genuinely affair because fifty-fifty if i allows it, they practise acquire a de Sitter, non anti de Sitter.
I would believe that i of these groups must acknowledge defeat shortly plenty because the claims together with arguments aspect rather straightforward.
Now, let's plough our attending to the novel Kachru-Trivedi paper. It's written equally a "positive paper" on effective acre theories of the KKLT-style flux vacua. I haven't read the newspaper inward its entirety but the abstract together with the full general arrangement of the newspaper does suggest that they're reviewing the thoughts that have got been unopen to from the KKLT. It seems to me that concerning the validity together with existence of the effective acre theories for the stringy situations, they ever rely on field-theory-based, e.g. Wilsonian arguments. I am non persuaded that this is goodness enough. String theory may invalidate the effective acre theories past times making sure that an energy-\(E\) effective theory isn't a local quantum acre theory at all.
What genuinely bothers me is the superficial approach of Kachru together with Trivedi to the arguments given past times the Vafa Team:
A recent newspaper [46 Obied Ooguri Spodyneiko Vafa], motivated largely past times no-go theorems alongside express applicability to a partial laid upward of classical ingredients, made a provocative conjecture implying that quantum gravity does non back upward de Sitter solutions. [Footnote virtually 2 previous papers maxim similar things.] Our analysis – together with to a greater extent than importantly, effective acre theory applied to the total laid upward of ingredients available inward string theory – is inward stark conflict alongside this conjecture. This leads us to believe that the conjecture is false.Do Kachru together with Trivedi consider this non-technical, judgmental paragraph to live plenty to bargain alongside the proposed option picture? OK, let's rephrase what they are saying:
We may repeat what nosotros said xv years ago. We may pay no attending whatsoever to the detailed arguments given past times the Vafa Team. We don't demand to live impartially interested inward the validity of the proposed novel principles, inequalities, together with no-go theorems. We just don't desire to larn whatever together with nosotros prefer to believe that no such novel insights exist. Instead, it's plenty to dismiss all these papers alongside a uncomplicated slogan, alongside slurs such equally "provocative" that brand the Vafa Team aspect express spell nosotros aspect unlimited, repeat that everything nosotros have got ever claimed to live truthful must live true, together with that's plenty to "prove" that nosotros are correct together with they are wrong.I am sad but it doesn't seem plenty to me. The claim that the Vafa Team's statements are express to a "partial laid upward of classical ingredients" spell Team Stanford is amend because effective acre theory is "applied to all ingredients available inward string theory" seems utterly demagogic to me. KKLT together with followers have got used lots of ingredients from string theory but there's no proof that they are "all" ingredients of string theory. New ingredients kept on emerging together with nosotros all the same can't show that nosotros know "all of them" because nosotros don't have got a universal Definition of string theory. Moreover, the high publish of such ingredients makes it to a greater extent than likely, together with non less likely, that i of them breaks downwards together with invalidates the KKLT construction equally a whole. So they have got many, non "all", ingredients of string theory together with this fact makes their construction to a greater extent than vulnerable, non less so!
And the really decision that "Vafa seems to disagree alongside something nosotros wrote hence he must live wrong" only looks childish. This is non a rational agency to argue. Vafa powerfulness say just the same thing – he doesn't – but none of these 2 stubborn propositions would imply a convincing declaration inward i agency or another.
Finally, nosotros have got the commencement newspaper past times Cicoli et al.; together with the last, 5th newspaper past times Akrami et al. These 2 papers explicitly claim to beak over the "de Sitter versus quintessence" tilt inward string theory. The Akrami newspaper seems to have got i proposed counterargument against quintessence that Akrami et al. are proud virtually together with that they desire to live carefully read past times the reader. What is it? They selection the constant \(c\) from the Vafa Team inequality, claim that it should live equal to i (or beingness of companionship one, they're non sure), together with and then they claim that the cosmological observations dominion out \(c\gt 1\) at the 3-sigma i.e. 99.7% level.
I am sad but the correct value of \(c\) isn't genuinely known, at to the lowest degree non likewise reliably, hence they can't decide the statistical significance well, either. The correct \(c\) could live \(1/3\) together with at that spot would live no exclusion at all. It seems to me that this overemphasis on the \(c\sim 1\) "prediction" together with its weak exclusion past times the observational information is their strongest argument. If that's so, I uncovering it extremely weak. Even if the calculation of the 3-sigma confidence degree were solid, which it doesn't seem to live at all, it is all the same just a 3-sigma confidence. Influenza A virus subtype H5N1 few years ago, the LHC diphoton bump was "discovered" at 4 sigma together with it was fake. Influenza A virus subtype H5N1 potential universal novel regulation of string theory is a dissimilar caliber. In my listing of priorities, if I acquire sufficiently sure virtually a novel universal regulation of physics, it may rhythm out fifty-fifty 5-sigma deviations from the predictions.
Finally, the first, Stanford-free newspaper is less arrogant than the Stanfordful papers. They prefer the de Sitter, KKLT-style models because they aspect concrete, at that spot seems to live a calculational control, together with it's acre getting amend alongside time. Quintessence is to a greater extent than "challenging" together with requires to a greater extent than fine-tuning, nosotros read. Well, Vafa et al. disagree alongside the minute point, likely both points. At whatever rate, they're potentially subjective. You can't exercise your feelings that something is "challenging" – without whatever particular declaration or quantification of the "challenge" – equally a persuasive declaration against an option theory.
So I am afraid that this Cicoli et al. newspaper is going to live likewise vague when arguing against the option moving-picture demo based on the novel full general principles proposed past times the Vafa Team. One problem, equally I have got mentioned, is that these 2 paradigms are really dissimilar from each other. They have got completely dissimilar advantages, really dissimilar numbers of requires solutions or corners of the stringy configuration space, dissimilar importance of the precision needed to analyze things, together with hence on. Depending on one's philosophy, the prior probabilities assigned to these paradigms may live really different. The probability ratio may really good live to a greater extent than extreme than 300-to-1 inward either administration – which makes some 3-sigma empirical arguments weaker than a weak tea.
At the end, it should live possible to resolve the controversy. But i only needs to report the purely stringy effects inward these compactifications (or would-be vacua) to a greater extent than accurately or to a greater extent than reliably than ever before. This increased command over the stringy effects or the increased reliability of the stringy arguments is likely necessary for whatever progress inward resolving this opened upward question. I haven't read the papers inward their entirety but I am afraid it is obvious that they haven't genuinely made whatever progress inward resolving the actual disagreement. They are basically repeating the things that were done earlier together with that's non a goodness path to progress.
And that's the memo.
No comments:
Post a Comment