Monday, March 17, 2014

Who should get the Nobel Prize for cosmic inflation?

Guest blog by Phil Gibbs, manager of

Graph added in the afternoon, LM.

Today at 4 pm British Summer Time we might hear some good news [and read some documents: already posted! \(r=0.2\) at 6-7 sigma; FAQ on the discovery] about a discovery of primordial gravitational waves and within a few more weeks that could be confirmed in more detail by Planck. If this happens the observational status of the theory of cosmic inflation will change dramatically because primordial gravitational waves have been described as a smoking gun for the theory. Well that may be an exaggeration but the observed scale invariance of the CMB anisotropy spectrum is already a good pointer towards inflation so could the combination be enough to sway the notoriously cautious Nobel committee towards awarding a prize for the theory?

Rumors say that Alan Guth and Andrei Linde have been invited to tomorrow’s meeting where the team of astronomers who work with the BICEP2 observatory in Antartica will announce a “major discovery” about B-modes in the cosmic microwave background. E-mode polarisation in the cosmic radiation was produced at the time of last scattering when it decoupled from atomic gas in the early universe. These E-modes could then have been distorted by the tensor modes of the primordial gravitational waves permeating space, twisting the polarisation field of the microwave background into the (hopefully) observed B-modes. So the B-modes are a signature of the gravitational waves that are themselves a remnant of the much earlier inflationary epoch of the universe.

The presence of Guth and Linde at this meeting echos the presence of Higgs and Englert at the announcement of the discovery of the Higgs Boson in 2012, and that is probably no coincidence. Just as Higgs and Englert were awarded the Nobel Prize last year for the theory behind the Higgs discovery, Guth and Linde will be prime candidates for any Nobel Prize awarded for the theory of inflation. However, there was much discussion about who else might have deserved the Higgs prize and the similar decision for inflation could be equally awkward and controversial.

Guth and Linde have already been jointly awarded several honours for their work on inflation theory including the Gruber Prize and Milner’s Fundamental Physics Prize, but the Swedish committee places a higher bar for empirical verification. The general idea of the inflationary universe may pass with the new evidence giving Guth his ticket, but Linde has worked on more specific models of inflation such as slow-roll and chaotic inflation. Brilliant and important though his work is, I am not convinced that he is destined for the Nobel yet. Argue with me if you disagree.

On the other hand Guth is not the only one with a claim to the original idea of inflation. It has been recorded that he first had the breakthrough idea on 6th December 1979, gave a seminar on the theory at SLAC on 23rd January 1980 and his paper was received on 11th August 1980. At around the same time Katsuhiko Sato in Japan had written a paper proposing inflation by 21st February 1980 which was received for publication on 9th September 1980, and another similar paper by Demosthenes Kazanas had already been received by 5th May 1980. All three contributions seem to have been independent and similar. The only thing that may have singled out the work of Guth was that his term “inflation” stuck and he was part of a more influential circuit of physicists. Closer examination of dates and the points they made in their papers may separate them, but I think it would be hard to be truly objective about what really counts.

But then all three were preempted by Soviet physicist Alexei Starobinsky who had already worked out the ideas behind inflation in 1979. Wikipedia describes his contribution like this
“Although Alexei Starobinsky of the L.D. Landau Institute of Theoretical Physics in Moscow developed the first realistic inflation theory in 1979 he failed to articulate its relevance to modern cosmological problems. Due to political difficulties in the former Soviet Union, regarding the free exchange of scientific knowledge, most scientists outside the USSR remained ignorant about Starobinsky’s work until years later. Starobinsky’s model was relatively complicated, however, and said little about how the inflation process could start.”
I think this is an overly negative view of his contribution and I suspect that it owes more to a bias that tries to rationalize the fact that we do not recognize his work as well as we recognize Guth’s. It is notable that he had already predicted the primordial gravitational waves in 1979 before anyone else had even started thinking about inflation. How the Nobel committee will see it I can only guess. Starobinsky did also win the Gruber prize independently of the prize given earlier to Guth and Linde. He was recognised along with Viatcheslav Mukhanov who, in colaboration with Chibisov (deceased), first calculated the spectrum of anisotropies from quantum fluctuations during inflation and who could therefore be yet another candidate for the Nobel. Once again the Nobel committee will again be inflicted with the headache that strikes them when more than three people deserve their recognition for the same discovery.


  1. Thanks, Phil, interesting review of some of the history!

    So because of your "too special" comments about Linde, do you also consider Andreas Albrecht and Paul Steinhardt to be out of the game?

    Don't you think that today, we might actually gain some information that will be more special than "inflation Yes/No", which would mean that some of the followups (long) after Guth may become empirically relevant?

  2. Yes I think Albrecht and Steinhardt are in the same boat as Linde. With four people independently forming the basic idea of inflation they seem to be further back, but of course this is open to debate.

    If this announcement gives just one number for peek amplitude it may rule out some inflation theories and highlight others but it will not be enough to label any particular theory as the right one I think. That may happen later when the spectrum is known. I actually think that the right inflation theory has not been found yet. I am even skeptical about the inflaton being a scalar.

  3. Thanks for your view and LOL, you added quite some bold comments. How could it be a non-scalar?

  4. Dear Phil, the inflation requires an exponential expansion which means locally de Sitter geometry,and de Sitter has the Einstein tensor proportional to the metric tensor, and it may only be extracted from the "int Lambda sqrt(-g)" cosmological-constant-like action. So the term driving inflation must effectively be constant, like A_0^2, but the time-like component of a gauge field may really be removed by a gauge invariance because it's pure gauge, unless you want to get ghosts and negative probabilities.

    Well, some people including Nima et al. are willing to get friendly with these ghosts, that's why it's called ghost inflation

    but I would assume the probability of less than 1% that this may really become kosher enough for Nature.

  5. If Nima et al have looked at something of this ilk then I can reclaim my sanity.

  6. What you say seems to be basically correct, but that doesn't refute what I was trying to say. What I claimed can be summarized in this brief paper:

    Anisotropy in Stelar Plasma Doppler Profile Disproves Cosmic Inflation


  7. WMAP then, becomes a Chaldni? :)

  8. It should definitely go to Starobinsky. Who the second person is gonna be debatable.

  9. Dear Nareg, I forgot to discuss Turok who may actually be even more interesting now. ;-)

    Turok had pretty distasteful battles with Guth and inflation recently, see e.g. blog posts

    Neil Turok is still the director of the Perimeter Institute. Not sure whether it's adequate to his currently pretty painful position. If I were his friend, I would recommend him to resign and hide somewhere.

  10. Thanks I will check them.

  11. Hi Lubos,
    Many thanks for the mention and for maintaining such an informative blog.
    Best regards,

  12. Thanks, Sam, for your interest and for drawing my attention to the rumor before I heard about it elsewhere!

    Don't forget to read Liam McAllister's blog post about what the discovery means for theorists:

  13. Mazikeen MorningstarMar 17, 2014, 8:20:00 PM

    He's so angry, but he is right loll

  14. The driest continent - sounds like they have developed a water vapor hole over Antarctica.

    How will the penguins get a drink? Much more serious than getting a sunburn.

    There's probably a cherished aspect of societal infrastructure that needs severe authoritarian government supression in order to cure this unnatural water vapor deficit.

    Should someone inform Susan Soloman?

  15. Thanks Luke,

    I will always be thankful to you because if I remember this correctly, it was you who pointed out my beloved Lenny lectures such that I got aware of them for the first time :-)

    Not sure, if I really passed you in some other sense ;-)

    Today I agreed with my general practitioner to take my comeback at work a bit slower, but then it will be ok I think :-)

    With this, I will also have more time to improve my knowledge about inflationary cosmology fore example, my kitty can get used gradually to my being away during the day, etc ...


  16. Please, Dilaton, try to make yourself feel good in the physical (body-related) sense as well. The body health and good condition is sometimes needed because the body serves as a pedestal for the brain and the mind, among other things. ;-)

  17. Peak. Not peek. I know, I know, I'm a grammar Nazi. Sorry. Other than that, good post.

  18. Thanks, I actually know that.

    I was afraid that you would say that the word "peek" doesn't exist. It was an English word I learned 7 years before I learned basic words in English, thanks to Commodore 64 BASIC. Print, input, go to, peek, poke, return, gosub - truly simple English. ;-)

  19. According to Linde, Erast Gliner deserves credit for original idea of inflation. From Linde's "Lectures on Inflationary Cosmology"

    _The history of inflationary cosmology goes back to 1965, to the papers by Erast Gliner [1]. He suggested that the Universe should begin its expansion in the vacuum-like state, and even calculated the desirable amount of inflation

    However, at that time almost nobody took his ideas
    seriously, except for Andrei Sakharov, who made an attempt to calculate density perturbations produced in this scenario._

  20. Pretty fascinating, never heard of this storyline.

  21. Here are the citations:

    [1] E.B. Gliner, Sov. Phys. JETP 22, 378 (1965); Dokl. Akad. Nauk USSR 192
    , 771 (1970); E.B. Gliner and I.G. Dymnikova, Pis. Astron. Zh. 1, 7 (1975); I.E. Gurevich, Astrophys. Space Sci.38
    , 67 (1975).

  22. Cool, I was trying to search for the papers but it was a bit hard.

    Are you also fighting Candida or where does your nickname come from? ;-)

  23. The name dates from my graduate school days. My doctorate is on prion replication in yeast.

    I'm a molecular biologist, so am not deeply familiar with this field.

    Gliner is my stepmother's uncle. My father, also theoretical astrophysicist, always talked about how Gliner originated this field and was not recognized for it.

    This week with the BICEP2 result in the news, I looked it up and found Linde's citation.

    Timothy Ferris has a similar citation in his book "The Whole Shebang: A State of the Universe Report."

  24. Nemáte někde přepis článků i v češtině?

  25. To bohužel opravdu nemám. Taková vymoženost by vyžadovala téměř dvojnásobnou práci a asi jen 4 procenta čtenářů jsou v této chvíli v Česku.

  26. After talking to someone who has world expert level knowledge about this topic, I appreciate now that this matter is quite complicated and interesting.

    I have set up a Reddit page laying out some basic facts and seeking further input from the community. Please have a look at perhaps you can direct interested readers here. Apologies for the sensationalistic headline... it is there to grab attention, not because I necessarily believe Gliner should get a Nobel.

  27. Who made the inflationary theory most popular and recognazible, I guess was Guth. So He should be on the roster of nobel recipients.