## Perfectoid Woodstock

Every year in Tucson the Arizona Winter School takes place, with a five day program on some topic in arithmetic geometry aimed mainly at advanced graduate students, designed to get them involved in current research-level topics. This year’s topic (Perfectoid Spaces) is drawing a huge number of people there next month, with about 450 participants expected (in the past numbers were more like 100). This should be a veritable Woodstock of arithmetic geometry, with no one I’ve talked to quite able to figure this out, thinking that there probably weren’t 450 people worldwide interested at all in arithmetic geometry. It seems everyone in the field will be there and then some.

Peter Scholze is the opening and closing act. The other lecturers who will take the stage have started to put lecture notes for their lectures on the school website.

Some are dubious that there really are 400 or so students in the world with the background necessary to understand this material. See for example MathOverflow where nfdc23 isn’t very encouraging to a student who doesn’t know any rigid analytic geometry, but plans to attend the AWS. In any case, I hear Tucson is quite nice in March.

At some kind of other end of the spectrum of such things, a couple months later experts will gather in Germany to discuss this field (see here). Also for about five days, at the Schloss Elmau Luxury Spa and Cultural Hideaway, the sort of place heads of state go for G7 meetings. Rooms run $600 a night or so, but in this case the tab is being picked up by the Simons Foundation. Sorry, by invitation only. Posted in Uncategorized | 22 Comments ## Math and Physics Social Media In the current situation, getting back to finding interesting news about math and/or physics to think about seems like a good idea, but I’ve been having trouble coming up with such news. Besides blogs, many of them listed on the right-hand margin of this one, I also follow some people on Twitter and on Google+. There are quite a few well-known physicists on Twitter at this point. On any given day you can learn something interesting from, for instance, Frank Wilczek or John Preskill (or see an epic throwdown between them). I’m sure there are many other mathematicians and physicists on social media that I’m not aware of, and open here to hearing suggestions. Part of the problem is that I’m now so old I figure I don’t even know what social media sites are out there. I hear there’s this thing called Facebook, but also that it’s now over as far as the younger generation is concerned. So, if you have a suggestion about where to find high quality news about math or physics on social media, whether it’s on Twitter, Google+, Facebook, Live Journal, Instagram, Pinterest, Snapchat, Yik Yak, Grindr or something else I’ve never heard of, please let us all know in the comments. Posted in Uncategorized | 17 Comments ## Fascism and the Current National Emergency After the election it seemed to me that it would be a good idea to ignore what Trump tweeted or said, and wait to see what he and the people he surrounded himself with would actually do. We’ve been finding this out over the past few days, and today the nature of the problem we face is now clear. The actions ordered today that are now being carried out by US officials around the world are the product of a deranged and dangerous personality who has surrounded himself with similar others. This is a national emergency with no parallel in our history. While the US has never seen the likes of this situation, Europe has, with Trump following a playbook familiar from the history of the 1930s. At this point the US may be one terrorist attack away from full-blown Fascism, this time with nuclear weapons. This needs to be stopped, now. The Constitution does provide two ways to deal with something like this: either the impeachment process or removal under the Twenty-Fifth Amendment as “unable to discharge the powers and duties of his office.” Many of Trump’s recent statements are clearly the product of delusional mind that is incapable of dealing with reality, and these delusions are now reflected in his actions. Removing Trump and those he has surrounded himself with will require the cooperation of a significant number of Republican legislators. Anyone who cares about US democracy should be trying to figure out how to get this to happen. Those of us in the US desperately need some good ideas about how to do this. Those in other countries should be pressing their governments and institutions to fight back against the US, as well as doing what they can to keep their own societies from following the US down this path. I’m moderating comments here and will only post one kind of comment: positive ideas about what to do about this emergency situation. At this point I think what’s needed are ideas way beyond suggestions of a “scientist’s march” to promote rationality. We need to figure out how to fight a new form of Fascism that has just come to power and is starting to rule by decree. Update: With the Republican Congress so far deciding to sit back and let Donald Trump, Steve Bannon and Stephen Miller rule by decree, all hopes for now are with the Judiciary. Last night a judge issued an emergency stay on parts of the executive order, this was followed by a statement from Miller on behalf of the White House that the order “remains in full, complete and total effect.” The suggestion to donate to the ACLU is a good one, they are on the front lines here. The President of my institution, Columbia University, at 1 am sent an email to the University community denouncing this executive order and involving the University in this in an unprecedented way: As I have said on many occasions, it is critically important that the University, as such, not take stands on ideological or political issues. Yet it is also true that the University, as an institution in the society, must step forward to object when policies and state action conflict with its fundamental values, and especially when they bespeak purposes and a mentality that are at odds with our basic mission. This is such a case. There is a petition being signed by academics here, which likely will have no effect, but I signed it anyway, and you may want to too. Update: A small glimmer of hope: a joint statement criticizing the executive order by Republican senators McCain and Graham, and a Twitter response from Trump identifying any opposition from them as “looking to start World War III”. World War III between Trump and Republican senators is what we all need to root for. Worth watching: news reports that the Trump administration is defying court orders requiring access to lawyers by detainees at Dulles airport. A decision by Trump and his people to defy court orders would provide grounds for impeachment. Update: Just wrote the following to a correspondent, thought I might as well also post it here. My advice would be to consider focusing on the following, and not getting distracted by the blizzard of appalling things one might reasonably find concerning about the current situation: • It was unclear who would actually be running things in a Trump administration (since Trump himself clearly neither knows nor cares about anything other than getting attention) until the past couple days. The answer now seems to be that it’s Steve Bannon of Breitbart. Bannon is a self-described “Leninist”, see for instance. His self-described goal is to tear the country apart: “to destroy the state… destroy all of today’s establishment.” This means he’s not just our enemy, but is also the enemy of much of the Republican Party, including for example John McCain and Lindsey Graham. He’s also not about to let himself be thwarted by the courts. I think we’re already seeing defiance of court orders, with a lot more of that to come. • There’s always the possibility of something like a military coup, but the only constitutional way out of this is impeachment or the 25th amendment route. This requires convincing a sizable number of Republican legislators that they have to abandon Trump and support his removal. To me, the big question here is what can be done to make that happen. How does one get the Republican establishment (legislators and/or Fox News, Wall Street Journal, etc.) to turn on Trump? My guess is that where they are now is that they know they have a problem on their hands, but are deathly afraid of Trump’s supporters, of ending up with their heads on a pike. • There’s not much time here. Looking at history, what happens next in this kind of situation is some episode of violence gets used to rally the country to the leader and justify his assumption of emergency power to rule by decree. We’re one episode of some enraged person shooting a lot of people away from that happening, in a country full of heavily armed angry people. • The best, most successful thing to hope for here is something I and maybe many of you find a depressing prospect: President Pence. But, there we are. Hoping I’m wrong about all of this… Update: Thanks to commenter Fred P. for the link to this. For something sensible from a conservative, see this by Eliot A. Cohen, which includes: For the community of conservative thinkers and experts, and more importantly, conservative politicians, this is a testing time. Either you stand up for your principles and for what you know is decent behavior, or you go down, if not now, then years from now, as a coward or opportunist. Your reputation will never recover, nor should it. Update: There was an incident last night (in Quebec City) of an enraged person shooting a lot of innocent people, killing 6 and wounding 8 others. Since the shooter was an Islamophobe and the victims were Muslims praying at a mosque, so this was of no use to Trump/Bannon, this has gotten just about zero attention. Update: The Quebec City shooter was a Trump fan radicalized by Marine Le Pen. Update: Terry Tao has a blog entry about this, emphasizing the damage to the math community. Update : Leonard Susskind has also decided to issue a statement warning about Fascism and the Trump administration, using his YouTube channel. Update: For commentary from historians of the rise of fascism in Germany on analogies with the current situation in the US, see Ron Rosenbaum and Isabel Virgina Hull. Posted in Uncategorized | 52 Comments ## Fake Physics 2016 so far wins my lifetime award for most depressing and disturbing year ever (on the front of the larger world one reads about in the newspaper and elsewhere, personally things are fine, thanks). Perhaps the most disturbing thing has been seeing the way in which people’s access to information about the larger world has become more and more dominated by what has become known as “Fake News”: stuff which is not true, but which someone with an agenda successfully gets others to believe. This is a problem that goes far beyond obvious nonsense fed to rubes on Facebook, to the point of including what a lot of my well-educated colleagues believe because they read it on the front page of the New York Times. I have no idea what to do about this larger problem and no intention of further discussing it here. I’ve started to come to the conclusion though that the most disturbing trend in theoretical physics of recent years may best be understood as a related phenomenon: “Fake Physics”. The first few weeks of 2017 are seeing a flood of examples of what I have in mind, including for instance: Note that the above examples are just ones written by physicists or reporting claims of physicists, there are also philosophers, theologians and others putting out similar articles, although without the claims to scientific authority coming from the physicists. Fake Physics VII just appeared and is rather bizarre. It essentially argues that the idea of assuming a Multiverse and using it to make statistical predictions doesn’t work. But instead of drawing the obvious conclusion (this was a scientifically worthless idea, as seemed likely to most everyone else), the argument is that we need a “revolution in our understanding of physics” that will make the idea work. Fake Physics shares several characteristics with Fake News: • It’s clickbait. While getting anyone to pay attention to the solution of a difficult technical problem in quantum field theory is likely to be nearly impossible, topics like “What happened before the Big Bang?” and “Did you know that there’s someone exactly identical to you somewhere else in the multiverse, and they’re dating Scarlet Johansson?” are sure crowd-pleasers. This motivates some physicists, and even more journalists, with the latter having the much better excuse that their livelihood depends on getting people to click on their stories. • It’s a propaganda tactic designed to mask failure. The main reason for the current mania for the Multiverse is the failure of the string theory unification program. Some who have invested their lives in this program have decided to use this sort of Fake Physics as an excuse to avoid admitting failure. • The group driving this is small but determined, ideology-driven and well-funded by rich people with an ax to grind. The majority of the community is unwilling to take on the unpleasant and unrewarding task of challenging them. While Multiverse Fake Physics plays a large role in media coverage of fundamental physics, partially because of funding from the Templeton Foundation, there are very few actual papers on the subject and “research” in this area is a small fraction of what theorists are doing. Most physicists just hope that if they ignore this it will go away. Unfortunately Fake Physics is not going away, but becoming ever more widespread. While I don’t know what to do about Fake News, I think there still is a chance to successfully fight Fake Physics and hope others will help with this. Update: There’s more • Fake Physics IX explains that the Many Worlds multiverse and the cosmological multiverse are one and the same. Sean Carroll is featured. • Fake Physics X includes the following from Carroll: David Chalmers does a wonderful job at making an important point: “A virtual world is just as real as a physical world.”… what’s real to one person might be virtual to someone else. People at Hacker News are discussing this. There I’m accused of “misleading people” by making them think the cosmological multiverse is the same thing as the Many Worlds interpretation. Oy. Update: Thanks to a commenter for pointing out Fake Physics XI, courtesy of Science Friday. As usual, the same vigorous ideologues promoting Fake Physics, the same dearth of voices pointing out the problems with it. Posted in Fake Physics, Multiverse Mania | 61 Comments ## Various and Sundry A few links for your weekend reading: • If you just can’t get enough of the Multiverse, Inference has commentary on Max Tegmark from Daniel Kleitman and Sheldon Glashow. • Coverage of the important topic of blackboards is to be found here. To those ill-informed sorts who think that blackboards are the past, whiteboards or some other technology the future, I’ll point out the following. When I came to Columbia back in 1989, there was a recently installed modest-sized whiteboard in the math department common room. Everyone hated it, and after many years it was replaced by a similar-sized blackboard. Last year, in a renovation of the lounge, that blackboard was replaced by a better one, and one whole wall of the room was replaced by a floor-to-ceiling blackboard. A year or so ago, a newly renovated Theory Center was unveiled here in the Physics department: floor-to-ceiling, wall-to-wall blackboards. That’s the future, the whiteboard is the past. • The latest CERN Courier has a long article by Hermann Nicolai, mostly about quantum gravity. Nicolai makes the following interesting comments about supersymmetry and unification: To the great disappointment of many, experimental searches at the LHC so far have found no evidence for the superpartners predicted by N = 1 supersymmetry. However, there is no reason to give up on the idea of supersymmetry as such, since the refutation of low-energy supersymmetry would only mean that the most simple-minded way of implementing this idea does not work. Indeed, the initial excitement about supersymmetry in the 1970s had nothing to do with the hierarchy problem, but rather because it offered a way to circumvent the so-called Coleman–Mandula no-go theorem – a beautiful possibility that is precisely not realised by the models currently being tested at the LHC. In fact, the reduplication of internal quantum numbers predicted by N = 1 supersymmetry is avoided in theories with extended (N > 1) supersymmetry. Among all supersymmetric theories, maximal N = 8 supergravity stands out as the most symmetric. Its status with regard to perturbative finiteness is still unclear, although recent work has revealed amazing and unexpected cancellations. However, there is one very strange agreement between this theory and observation, first emphasised by Gell-Mann: the number of spin-1/2 fermions remaining after complete breaking of supersymmetry is 48 = 3 × 16, equal to the number of quarks and leptons (including right-handed neutrinos) in three generations (see “The many lives of supergravity”). To go beyond the partial matching of quantum numbers achieved so far will, however, require some completely new insights, especially concerning the emergence of chiral gauge interactions. I think this is an interesting perspective on the main problem with supersymmetry, which I’d summarize as follows. In N=1 SUSY you can get a chiral theory like the SM, but if you get the SM this way, you predict for every SM particle a new particle with the exact same charges (behavior under internal symmetry transformation), but spin differing by 1/2. This is in radical disagreement with experiment. What you’d really like is to use SUSY to say something about internal symmetry, and this is what you can do in principle with higher values of N. The problem is that you don’t really know how to get a chiral theory this way. That may be a much more fruitful problem to focus on than the supposed hierarchy problem. • Progress in geometric Langlands marches on, with a new paper yesterday from Aganagic, Frenkel and Okounkov on the Quantum q-Langlands Correspondence, a two-parameter generalization of geometric Langlands. Among many other things, they formulate (Conjecture 6.3) a conjecture generalizing the characterization (using BRST methods) of affine Lie algebra representations at the critical level that from the beginning of the subject described a major aspect of how geometric Langlands works locally (for details on this, see Frenkel’s book Langlands Correspndence for Loop Groups). Posted in Uncategorized | 59 Comments ## New Year’s Multiverse I see little to be hopeful about the new year, but had a glimmer of a hope that we’ll see a reduction in Multiverse Mania. Surely people will sooner or later get tired of stale pseudo-science. Just got back to work from vacation and it seems that so far this is not working out at all, quite the opposite. At the yearly Edge question site, Martin Rees’s answer to the question “What scientific term or concept ought to be more widely known?” is The Multiverse, and he starts out with the usual sort of breathless hype: An astonishing concept has entered mainstream cosmological thought… Critics of the multiverse are described as having two arguments: • “Some claim that unobservable entities aren’t part of science.” • “Some physicists don’t like the multiverse: they’d be disappointed if some of the key numbers they are trying to explain turn out to be mere environmental contingencies governing our local space-time patch—no more truly “fundamental” than the parameters of the Earth’s orbit round the Sun.” The first of these is the usual straw man argument, painting multiverse critics as too ignorant to realize that much of science is based upon indirect evidence, not direct observation. The actual argument of this sort against the multiverse is not that we can’t get direct evidence for it, but that there is no evidence of any kind for it, direct or indirect, and no plausible prospects of getting any. This case has been made ad nauseam here on this blog. The second of these arguments is treated in much more detail in a new article at Nautilus by string theorist Tasneem Zehra Husain with the title Even Physicists Find the Multiverse Faintly Disturbing. Husain treats in detail the question of how physicists “feel” about the multiverse, and like Rees, makes the point that what physicists don’t “like” about the multiverse is that it removes hopes of being able to do things like understand the nature and strengths of fundamental forces, or calculate the masses of elementary particles. Rees tells us that physicists are wrong to feel this way, that instead they should be awed by “the revelation that physical reality was grander and richer than hitherto envisioned” and that “If we’re in a multiverse, it would imply a fourth and grandest Copernican revolution.” Husain in the end seems to agree, quoting Gian Giudice: Perhaps we need to let go of something we’re holding onto too tightly. Maybe we need to think bigger, refocus, regroup, reframe our questions to nature. The multiverse, he says, could open up “extremely satisfying, gratifying, and mind-opening possibilities.” Of all the pro-multiverse arguments I heard, this is the one that appeals to me the most. In every scenario, for every physical system, we can pose infinitely many questions. We try to strip a problem back to the essentials and ask the most basic questions, but our intuition is built upon what came before, and it is entirely possible that we are drawing upon paradigms that are no longer relevant for the new realms we are trying to probe. The multiverse is less like a closed door and more like a key. To me, the word is now tinged with promise and fraught with possibility. It seems no more wasteful than a bower full of roses. Rees and Husain do a good job of showing that if science is about feelings, then Multiverse fans have a fine argument against critics arguing based on their negative feelings. The problem of course is that science is not about feelings but about evidence. The argument by critics that needs to be addressed is that there is no evidence at all for current multiverse scenarios, and no plausible way of getting any by scientific methods. Nautilus has another multiverse-related piece just out, We Have Pushed Physics Too Far, by Marcelo Gleiser. My reading of the piece is that Gleiser agrees that the Multiverse is not successful science (“Parallel universes are a non-answer”), and I believe most physicists also agree. Unfortunately the lessons he draws from this (as I’m afraid many others are doing) is that the problem not a particular research program that failed (string theory, by ending up with the string landscape and the multiverse), but the whole idea of pursuing mathematical ideas about further unification: We can call this the ultimate Platonic dream, the quest for a single simple and broad-ranging theory of physics. Indeed, during the past four decades, the search for such a theory has inspired many of the brightest physicists in the world. But today we are seeing the limits of this Platonic thrust to mathematize nature, due to a lack of experimental validation and several theoretical obstacles—including the possibility of multiple universes and the troubling questions they pose. Gleiser sees successful physics as “an expression of intellectual humility”, with our current problem that of Icarus, trying to fly too close to the sun. I strongly disagree with him about this, seeing some of the best of physics as an expression of intellectual arrogance, not humility. It is intellectual arrogance that has gotten our understanding of nature as far as it has gone, and it will require intellectual arrogance to go farther. The current problem of theoretical physics is due not the sin of arrogance, but to a somewhat different one, that of refusing to admit error. Multiverse mania is largely about the refusal to admit that string theory unification is a failed idea. Yes, arrogance is one reason for this refusal, and admitting failure takes some humility. But then moving on to find different, more successful ideas will require a lot of both mathematics and intellectual arrogance. Update: One more article at Nautilus about the multiverse. At least this one is explicitly theology, it explains: a section of liturgy recited whenever we take the Torah out of the ark, and it’s related to a prayer that many Jews know, “Adon Olam.” The phrase is usually translated as “Sovereign of the Universe,” where the word olam can mean both “the universe” and “eternity,” expressing tremendous expanses of both space and time. But in this particular section of the Torah service, God is called “Adon Olamim,” where the suffix -im makes the word plural. This means that God is “Sovereign of the Universes,” as in, “more than one universe.” God doesn’t need to be a designer who had a specific plan in mind that led to the creation of humanity. God is, in fact, the Sovereign over all the universes, including the ones that don’t have life in them. Update: Yet more explicit theological coverage of the Multiverse at science magazine Nautilus, with an article from Mary-Jane Rubinstein, a professor of religion, who is interested in multiverse versions of pantheism and explains: As a professor of religious studies, I am particularly drawn to the places where religion and science seem antagonistic, but turn out to be entwined. The multiverse, I would argue, is one of those places. My only disagreement here would be whether being a place where science and religion are intertwined is a good or bad thing… Update: Yet more in the Nautilus series on the Multiverse: more theology, and now teleology. Update : In case you were worried that Multiverse pseudo-science was incompatible with the Quran, have no fear. Update: 2017 is well on its way to a bumper crop of Multiverse Mania. Today it’s New Scientist’s turn. Update: This crap is just endless, more every day. Today it’s at Astronomy Magazine, about this nonsense, debunked long ago by Jennifer Ouellette. Posted in Multiverse Mania | 73 Comments ## What Graduate School in Theoretical Physics is Really Like I’m about to head off for a short New Year’s vacation in West Texas, but wanted to recommend a wonderful article that just appeared at Nautilus. It’s a memoir by Bob Henderson (who I met when he wrote about me, see here), appearing under the title What Does Any of This Have To Do with Physics? (although the title of the web-page, What Graduate School in Theoretical Physics is Really Like, is more descriptive). Henderson was a graduate student at Rochester in theoretical physics, working with S.G. Rajeev. He later went to work on Wall Street, and more recently in journalism. His Nautilus piece is the best explanation I’ve ever seen of what it’s like to start working in this field as a graduate student, should certainly be required reading for anyone thinking of going into the subject. It’s also somewhat of a profile of Rajeev, who has worked on a wide variety of topics in theoretical physics. One of the main themes of the piece is Henderson’s thinking about how and why he left theoretical physics, why he “quit”. Something to keep in mind is that this kind of decision is what most people who get Ph.Ds in the subject end up facing. There are 5-10 times more people getting Ph.Ds in this field than there are permanent positions doing research in it, so the career path starts out with a game of musical chairs that you are highly likely to lose. Different people make the choice to quit the game and do something else at different points and in different ways. Henderson does an excellent job also of explaining what the real problem is with doing this kind of research: that of figuring out what the right thing to calculate is. For everyone, but especially for those at the beginning of a career, the subject is a huge collections of topics one doesn’t understand. One has to somehow choose a direction to pursue, and it most likely won’t go anywhere: Writers talk of the terror of facing a blank page, but it’s no different for theorists like Rajeev trying to choose which path to take. There are an infinite number to choose from, and most go nowhere or back from where you came. The clock is always ticking and you spend so much time in the dark that it can make you not only question your path, but your own self worth. It can make you feel stupid. Sticking with this and making a career of it involve some combination of good luck (being in the right place at the right time), ability, self-confidence, not having a family to support, and a host of other factors. As Rajeev explains to him: Without naming names, he ticked through a catalog of his contemporaries who’d succeeded in theoretical physics even without having the towering mathematical intellect that I was sure it took and that Rajeev surely has. They’d made it, Rajeev explained, by focusing on problems that played to their strengths, or by taking advantage of computers, or by collaborating with peers who had complementary skills. Some socially gifted but not so mathematically talented types had gone quite far this way, earned a lot of renown. Anyway, the whole piece is well-worth reading. Another recently published Nautilus piece that I learned about from a link on this one is The Universes of a Woman in Science. It’s by Kate Marvel, who shares with Henderson (and hundreds if not thousands of others…) the experience of getting a theoretical physics Ph. D. (string cosmology in her case), and then leaving the subject for another field (in her case, climate science, which she blogs about here). Posted in Uncategorized | 47 Comments ## Various Links A grab-bag of unrelated topics and links: • Continuing the subject of budget cuts from the last posting, I heard today that the NSA is not funding this year the grant program that the AMS has been running for it, called the NSA Mathematical Sciences Program. In typical NSA fashion, no real reason given: after much deliberation our senior management has decided that the MSP will not have the resources to make new awards in FY2017. Even less information is available than in the case of the similarly mysterious DOE HEP Theory cuts, since all information about the NSA budget, even the total, is classified (although from Snowden and others, it seems that it’s about$10.5 billion).

• The IHES has a new website.
• This spring Peter Scholze will give a series of six lectures at the IHES on the latest about the local Langlands conjectures.
• Via David Roberts, the LMS has some videos about mathematicians here. Kevin Buzzard explains Langlands:

The Langlands philosophy? Yeah, that’s like Birch-Swinnerton-Dyer on crack, isn’t it?.

• Tate’s collected works are finally available from the AMS.
• Turning to physics, there’s a very good new article at Quanta from Natalie Wolchover about the unsuccessful search for proton decay and what this means for grand unification ideas. Glashow has now given up, with the simplest GUTs now conclusively ruled out:

Glashow, for one, largely lost interest in the whole affair when SU(5) was ruled out. “Proton decay has been a failure,” he said. “So many great ideas have died.”

Not everyone has given up though, with fans of the “flipped SU(5)” SUSY GUT explaining things this way:

Barr, one of the originators of the still-viable “flipped SU(5)” GUT model, compared the situation to waiting for your spouse to come home. “If they’re 10 minutes late, there’s simple explanations for that. An hour late, maybe those explanations become a little less plausible. If they’re eight hours late … you begin to worry that maybe your husband or wife is dead. So the point is, at what point do you say your theory is dead?”

Right now, he said, “we’re more at the point where the spouse is 10 minutes late, or maybe an hour late. It’s still completely plausible that grand unification is correct.”

Besides the current wishful thinking, this particular model has a strange history. You can read here about how it follows from Vedic Science. Over the years it has been about to come home many times, see this from 2012, which assures us that:

The CMS and ATLAS experiments have also observed tantalizing hints of the unique signature predicted by the Flipped SU(5) model.

At this point, it seems to me to be way more than an hour late, time for its nearest and dearest to admit that it’s dead (or maybe has run off with its TM instructor).

• I don’t always agree with Sabine Hossenfelder about math, but I very much agree with the conclusion of this posting:

In lack of experimental guidance, what we need in the foundations of physics is conceptual clarity. We need rigorous math, not claims to experience, intuition, and aesthetic appeal. Don’t be afraid, but we need more math.

• There’s a Recent Developments in Fields, Strings, and Gravity conference going on this week at the new Center for Quantum Mathematics and Physics at Davis.
• Videos of the talks at the recent John Schwarz 75th birthday conference at Caltech are available here.
• Multiversal Journeys is an organization devoted to promoting theoretical physics, with a heavy dose of multiverse mania as part of their story. They have a new book coming out, Quantum Physics, Mini Black Holes and the Multiverse, supposedly “Debunking Common Misconceptions in Theoretical Physics”. It seems that one of these common misconceptions is that the multiverse is pseudo-science. To fight this, they’ve also produced a promotional video.
• Bert Schroer has an interesting preprint with a lot of material about Rudolf Haag and algebraic quantum field theory.
• Another intriguing preprint recently out is from Arkani-Hamed and collaborators. In the past Arkani-Hamed has been vehement about gauge symmetry just being a worthless redundancy in our description of physics, for instance stating:

What’s as a misnomer called gauge symmetry, whose beauty is extolled at length in all the textbooks on the subject, is completely garbage. It’s completely content free, there’s nothing to it.

In the new paper, instead of gauge invariance being useless, there’s a conjecture that locality and unitarity, instead of being fundamental principles, follow from gauge invariance.

There’s a long tradition in the philosophy of physics literature of arguing over whether gauge symmetry is a fundamental idea or a useless redundancy. I’m on “fundamental idea” side, but of course exactly what the role of gauge symmetry is in fundamental physics is something that we have yet to fully comprehend.

Posted in Langlands, Multiverse Mania, Uncategorized | 29 Comments

## HEP Theory Letter

A couple weeks ago a large group of US HEP theorists wrote a letter to the DOE High Energy Physics Advisory Panel (HEPAP) (available at page 7 here) expressing alarm at trends in DOE funding of HEP theory, ending with

We formally request that a subpanel of HEPAP be formed to investigate and better understand this damaging trend and to make recommendations to address its consequences and restore a thriving Theory program, and we strongly urge that HEPAP support measure to rebuild and maintain the prominent and world-leading standing of US High Energy Theoretical Physics.

The letter claims that since 2011 the overall DOE HEP Theory program has been cut by 17%, with the university component of this cut by 30%. It also claims that 25% of DOE-supported university theorists have had their funding cut off in the last four years, with the number of postdocs going down by about 30%.

At last week’s HEPAP meeting there was a discussion of this, but I don’t know what was decided. Some numbers presented there indicated that from FY2013-2015. the DOE theory budget went from $51.2 million to$49.32 million. The net number of funded PIs was reduced by more than 10% (25 out of about 230), with 52 PIs dropped, 27 new ones coming in. The conclusion of that presentation was that “The theory program in its current state cannot be described as thriving.” The emphasis in the letter and this presentation on “thriving” is a reference to one of the P5 recommendations that is supposed to be governing how the DOE HEP budget is allocated:

The U.S. has leadership in diverse areas of theoretical research in particle physics. A thriving theory program is essential for both identifying new directions for the field and supporting the current experimental program.

The most detailed recent information I can find about the DOE HEP theory budget is in this presentation from August. It shows a decline from FY10 to FY16 from $53.09 million to$46.69 million, with most of this in the component going to university groups, which went from $27.25 million to$21.765 million. The current number of postdocs supported is listed as about 125 (100 at universities, 25 at the labs), the number of graduate students is about 120.

Concern about this decrease in funding first became public two and a half years ago (see my blog post here) with Sean Carroll’s blog post describing a “calamity”. Various HEPAP presentations warned physicists about the dangers of public complaints and these died down for a while, but the continuing cuts to the university component of theory funding seem to have led to the decision to send this new letter.

An odd part of this story is that it’s unclear why this decision to reduce DOE HEP theory university funding significantly was made. It’s true that the overall DOE HEP budget has been cut over the same period (from $810.5 million in FY10 to$795 million in FY16) but unknown why the university theory component was cut 20% over this period while the overall cut was only 2%. Note that none of these numbers are adjusted for inflation.

It would be very interesting to hear comments from anyone who knows more about what is going on here. The usual generic comments that government spending is bad will be deleted. Keep in mind that the amount of money at issue here is (2.7% of the HEP budget, .00058% of the total federal budget) very small on the scale of government funding of science, and now ever small on the scale of private science funding (the Simons Foundation alone last year gave out \$233 million in grants).

Update: A full copy of the letter with all signatures is here. An explanation of where the numbers in the letter come from is here.

Posted in Uncategorized | 28 Comments

## Anomaly!

Tommaso Dorigo’s new book Anomaly! Collider Physics and the Quest for New Phenomena at Fermilab has just become available. I highly recommend it to anyone with an interest in high energy physics who wants some insight into how collider experiments are done. Dorigo is a well-known blogger, with the best (as well as most entertaining) blog there is about the experimental side of high energy physics. If you’re not following his blogging, you should be.

The nominal topic of the book is research conducted at the Tevatron by the CDF experiment during the 80s and 90s, into the early 2000s. Some of the specific well-known CDF results discussed in detail include measurement of the Z mass and the discovery of the top quark. The material about the top quark discovery comes closest to the kind of thing you find in other books. It’s a very well-done insider’s account of the story of an important discovery. I don’t know of a better place to read about the top quark search and how it finally succeeded.

One of the most unusual aspects of the book, in evidence in the top quark section and throughout the rest, is that it goes much deeper into an explanation of how collider experiment physics analyses are actually done than is usual in a popular or semi-popular book. Besides the insider’s local color and insights into the personalities involved, there’s quite a bit of discussion of the technical issues of the subject. This is a subject involving thorny issues of how best to reconstruct the properties of particles coming out of collisions, and finding clever new ways to deal with these while avoiding subtle pitfalls is a central problem, one outsiders normally don’t get to hear about.

The other unusual aspect of the book is that it doesn’t just discuss success stories of striking discoveries (of which there hasn’t been much between the top and the much later Higgs discovery at the LHC). One of the main activities of the field has been the search for “anomalies”, experimental results that disagree with the Standard Model and point to new physics. The problem is that finding anomalies is common, but they almost certainly will turn out to be due to some problem with the experiment or its analysis (such problems are always much more likely than revolutionary new physics).

One of the stories of an anomaly described extensively is that of an excess of high transverse energy jets, something that one might expect to see if quarks had some substructure (“preons”). Here the problem turned out to have a lot to do not with the experimental result, but with the theoretical modeling of what to expect from QCD. Another example is the story of “superjets”, events involving a W and 2 or 3 jets, with unusual properties.

For the “superjets” and for other anomalies, a favorite explanation was to invoke supersymmetry, since supersymmetric models predict a large range of different kinds of new particles, and one might hope that any anomaly is due to one of them. Dorigo has a few stories about theorists I hadn’t heard, in particular that of a fall 1995 letter signed by many prominent theorists (except Howard Georgi, who refused to sign). Despite ongoing efforts to look for superpartners, all of which had been unsuccessful, the feeling of the theorists was that the Fermilab experimenters weren’t trying hard enough. The letter was sent to the Fermilab director as well as the CDF and DZERO spokespersons. It explained what a great idea supersymmetry was, and ended with

We, the undersigned, believe that Fermilab has unique detection possibilites for supersymmetry, and urge you to direct your laboratory’s efforts in that direction, and ask the leaders of the collider detector collaborations to intensify their search for massive superpartners.

For more than two decades now, such searches for superpartners have been one of the dominant activities of collider experiments, with well-known negative results.

Finally, another important and unusual theme that runs through the book is the question of how to statistically characterize the significance of an anomaly. This is a topic where Dorigo is very much an expert, recently heading the CMS Statistics Committee.

Anomaly! is both a great tale of how science is really done, and an unusually insightful exploration of the crucial question of how one evaluates the significance of hints of new experimental discoveries. This question is of central importance now as the LHC gathers and analyzes data in a previously unexplored energy range. There are undoubtedly anomalies galore being studied by the LHC scientists, almost all of which will never be heard of by the public, as the experiments cautiously work to eliminate every possible conventional physics explanation for the anomaly. The 750 GeV diphoton bump of the past year is one example of an anomaly that made it out to a public announcement, with its disappearance in this year’s data making clear why the experiments are so cautious. You can’t find out about these ongoing stories, perhaps for good reason, due to the policies of how collider experiments are run, but now you can buy a copy of Anomaly! and at least read about how things played out in the previous generation of such experiments. This background should be helpful to make sense of what is going on if and when (March?), the next LHC anomaly gets reported.

Posted in Book Reviews | 5 Comments