Which conference lineup interests you more? (Strings '11 or mixed-QG 11)

[marcus]

The opening talk of Strings 2011 by David Gross can be seen here:
http://media.medfarm.uu.se/flvplayer/strings2011/video1

The other talks can be watched live, as they are given. Just now I was watching the talk by Niklas Beisert.

To find the relevant links, go to the programme webpage.
http://www-conference.slu.se/strings2011/programme_NEW.html

The list of registered participants has 259 names:
https://www.akademikonferens.se/list.jsf?conf=strings2011-S

The quality of the sound and video is excellent IMO, at least by my standards.

Unfortunately Sweden time is 6 hours ahead of East Coast Usa time, and 9 hours ahead of Pacific (my time).

So for example Witten talks at 11 AM in the morning on Tuesday. Which means I would have to get up at 2AM tomorrow morning to hear the talk live. Or someone on the East coast would have to get up at 5AM. So watching most of the talks live is out of the question.

Presumably stored versions of the other talks will eventually be posted online in the same way as Gross's opening speech.

For now, six are so available. Besides Gross's there are:
Michael Green http://media.medfarm.uu.se/flvplayer/strings2011/video2
Thomas Klose http://media.medfarm.uu.se/flvplayer/strings2011/video3
Henrik Johansson http://media.medfarm.uu.se/flvplayer/strings2011/video4
Fabio Zwirner http://media.medfarm.uu.se/flvplayer/strings2011/video5
Niklas Beisert http://media.medfarm.uu.se/flvplayer/strings2011/video6

 

[marcus]

Henriette Elvang's review of scattering amplitudes (crisp well-organized fast-moving)
http://media.medfarm.uu.se/flvplayer/strings2011/video9

Witten's talk
http://media.medfarm.uu.se/flvplayer/strings2011/video10
The link did not work, probably because so many people are trying to watch his talk and there is a simple overload of the resources. Perhaps later.

By now they have put up video for a dozen or so, the links are consistently numbered in the order that the names appear in the programme:


David Gross
Michael Green
Thomas Klose
Henrik Johansson
Fabio Zwirner
Niklas Beisert
Sergio Cecotti
Dimitrios Tsimpis
Henriette Elvang
Edward Witten
Samson Shatashvili
Alexei Morozov

..., you have big names like Wilzcek, Verlinde and Linde with very tasty titled talks.

Judging from the title, Verlinde is giving the same talk (The Hidden Phase Space of Our Universe) that he gave at Perimeter last week on 22 June. It is certainly interesting despite or perhaps because on a divergent track from the rest of the conference.
Here is the Perimeter video:
http://pirsa.org/11060065/
The Hidden Phase Space of our Universe
Erik Verlinde
So there is no need to wait until Friday, when he gives the talk at Uppsala. One can watch it already on the Perimeter archive.

I too look forward to Wilczek's talk on Thursday. I think it will be another divergent . talk. As you say, the title is "tasty". His topic is three different BSM futures that could I suppose follow from, for instance, LHC results.

 

[unusualname]

The Hidden Phase Space of our Universe
Speaker(s): Erik Verlinde
Abstract: By combining insights from black holes and string theory we argue for the existence of a hidden phase space associated with an underlying fast dynamical system, which is largely invisible from a macroscopic point of view. The dynamical system is influenced by slow macroscopic observables, such as positions of objects. This leads to a collection of reaction forces, whose leading order Born Oppenheimer force is determined by the general principle that the phase space volume of the underlying system is preserved. We propose that this adiabatic force is responsible for inertia and gravity. This fact allows us to calculate the hidden phase space volume from the known laws of inertia and gravity. We find that in a cosmological setting the appearance of dark energy is naturally explained by the finite temperature of the underlying system. The adiabatic approximation that leads to the usual laws of inertia and gravity breaks down in the neighborhood of horizons. In this regime the reaction force degenerates into an entropic force, and the laws of inertia and gravity receive corrections due to thermal effects. A simple estimate of these effects leads to the conclusion that they coincide with observed phenomena attributed to dark matter.

Dark energy I think will have some not so spectacular explanation, maybe even like Verlinde is suggesting here, but wow, that's a pretty risky claim about dark matter. If supersymmetry is found at the LHC then many people expect dark matter to be neutralinos.

Still with the recent few millions euros of funding for Verlinde's programme I think this will develop pretty quickly, and we shouldn't have to wait more than a year or two for dismissal or support (if the LHC doesn't get there first)

 

[marcus]

Heres a link if anybody wants a list of the Strings 2011 talks for which videos are online.
http://media.medfarm.uu.se/flvplayer/strings2011/

There is usually no wait, and the quality is excellent!

At present videos of 21 talks are available.

To my way of thinking the most interesting and at the same time divergent talk of the conference will not be given at Uppsala until Friday 1 July, but has already been given at Perimeter Institute last week (22 June) and is also available in excellent video online:
Here is the Perimeter video:
http://pirsa.org/11060065/
The Hidden Phase Space of our Universe
Erik Verlinde

I'm not sure but I think Unusualname might agree with me. Unusual points out that Verlinde may be betting against low-energy Susy. The nice explanation of Dark Matter from Susy requires that supersymmetry appear at low energy so that it would be detected at CERN in the next couple of years. Suppose it is not (which I think is quite possible). This would make Verlinde's theory look good because he has a different idea of how effects attributed to Dark Matter might arise.

(I suspect he is wrong about DM. It already has too many different observed effects and its material existence is too well established. He says at the outset that his ideas about DM are speculative--but they are still very interesting.)

 

[unusualname]

Heres a link if anybody wants a list of the Strings 2011 talks for which videos are online.
http://media.medfarm.uu.se/flvplayer/strings2011/

There is usually no wait, and the quality is excellent!

At present videos of 21 talks are available.

To my way of thinking the most interesting and at the same time divergent talk of the conference will not be given at Uppsala until Friday 1 July, but has already been given at Perimeter Institute last week (22 June) and is also available in excellent video online:
Here is the Perimeter video:
http://pirsa.org/11060065/
The Hidden Phase Space of our Universe
Erik Verlinde

I'm not sure but I think Unusualname might agree with me. Unusual points out that Verlinde may be betting against low-energy Susy. The nice explanation of Dark Matter from Susy requires that supersymmetry appear at low energy so that it would be detected at CERN in the next couple of years. Suppose it is not (which I think is quite possible). This would make Verlinde's theory look good because he has a different idea of how effects attributed to Dark Matter might arise.

(I suspect he is wrong about DM. It already has too many different observed effects and its material existence is too well established. He says at the outset that his ideas about DM are speculative--but they are still very interesting.)

I haven't had a chance to view the Verlinde talk yet, but I applaud his bravado in claiming that even dark matter may have an entropic explanation.

If the LHC finds the Higgs boson at ~115-120Gev (or so) then that will really support the Minimal Supersymmetric Standard Model, which suggests dark matter is neutralinos.

I'm surprised Verlinde's talk is at a Strings conference, seems the string guys are loosening up a bit and allowing speculative non-stringy ideas at their showpiece annual conference!

 

[marcus]

...
I'm surprised Verlinde's talk is at a Strings conference, seems the string guys are loosening up a bit and allowing speculative non-stringy ideas at their showpiece annual conference!

They've GOT to!
Look at the numbers.

Annual first-time faculty hires (US and Canada) in HEP theory as a whole, and in string, averaged over 3 year periods

period                           1999-2001    2002-2004   2005-2007    2008-2010
annual HEP theory hires as a whole      18           24          23           13
annual string hires                      9            8           6            2

Registered participants in the annual conference (some years omitted for brevity)

Strings 2003 Kyoto     396
Strings 2005 Toronto   415
Strings 2007 Madrid    440
Strings 2009 Rome      450
Strings 2010 Texas A&M 193
Strings 2011 Uppsala   259

Number of recent string papers making the top fifty in the annual Spires HEP topcite list

year (some omitted for brev.)   2001    2003    2005    2007    2009    2010
recent work highly cited in year  12       6       2       1       1       0

A paper is counted as recent if it appeared in the previous five years. This gauges the quality/significance of current work by how other researchers receive it.

Links to sources here
https://www.physicsforums.com/showthread.php?p=3373453#post3373453

The program is losing perceived relevance. They have to "loosen up a bit", as you put it.

 

[unusualname]

yeah, but Strings is much harder than the other toy stuff, so it's no surprise if those numbers you quote are declining while we wait for some experimental support from the LHC.

I think it's inconceivable, if you look at the history of physics, that so many people in such prestigious academic positions, could be completely misled up the wrong path.

 

[marcus]

...
I think it's inconceivable, if you look at the history of physics, that so many people in such prestigious academic positions, could be completely misled up the wrong path.

Don't be too sure. And keep an eye on where the research interests of some of the best are tending.

 

[suprised]

I'm surprised Verlinde's talk is at a Strings conference, seems the string guys are loosening up a bit and allowing speculative non-stringy ideas at their showpiece annual conference!

"loosening up a bit and allowing"… you guys have a completely wrong perception of how things actually are! No one would mind, were it not that other people would be influenced by this desinformation. Quite oppositely, Erik's ideas _are_ related to string theory as they involve matrix theory. Just care to read the first sentence of the abstract of his talk at Perimeter:

" By combining insights from black holes and string theory we argue …."

And marcus, thanks for your tip! The professional scientists are just too grateful to get advice from recreational armchair experts!

 

[MTd2]

I think it's inconceivable, if you look at the history of physics, that so many people in such prestigious academic positions, could be completely misled up the wrong path.

Epicycles...

 

[marcus]

Heh heh. Don't forget Phlogiston.
Or the Aether.

A few posts back I mentioned the conference attendance figure for Strings 2011. It is actually 257 (see https://www.akademikonferens.se/list.jsf?conf=strings2011-S ) so I'll correct the table.

Registered participants in the annual conference (some years omitted for brevity)

Strings 2003 Kyoto     396
Strings 2005 Toronto   415
Strings 2007 Madrid    440
Strings 2009 Rome      450
Strings 2010 Texas A&M 193
Strings 2011 Uppsala   257

Here's the main video link:
http://media.medfarm.uu.se/flvplayer/strings2011/
David Gross's opening talk provided, I think, a good window on the state of things in the string program generally, possibly also the mood.
Gross-- http://media.medfarm.uu.se/flvplayer/strings2011/video1
Frank Wilczek gave an invited talk on "three ways beyond the standard model". None were stringy. He described his approach as "bottom up" and "zero-brane". Talked mostly about his first two topics: quantitative unification and axions. To stay within time he had treat the planned third topic (portals) lightly.
Wilczek-- http://media.medfarm.uu.se/flvplayer/strings2011/video24
Wilczeck made a special point of praising Fabio Zwirner's talk, the only talk at the conference he cited or recommended. It was also not a string theory talk, actually, but was about LHC results:
Zwirner-- http://media.medfarm.uu.se/flvplayer/strings2011/video5
Verlinde's talk is tomorrow. Here's the advance copy.
Verlinde-- http://pirsa.org/11060065/

 

[marcus]

Peter Woit had an interesting Update on Strings 2011 today
==quote==
Update: After looking at most of the talks online, the most remarkable thing about Strings 2011 is how little there is about string theory. One of the speakers, Chris Hull, started off his talk with the comment:

At lunch today one of the organizers was observing that my talk was unusual in being one of the few talks actually about string theory. It would be interesting to speculate on what that might mean about the state of the field, but it would be invidious to do so here.
​

One of the main themes of the conference so far has been study of mathematically interesting supersymmetric QFTs in 3,4,5 and 6 dimensions, often obtained from a specific class of 6d theories, which themselves remain poorly understood (what is known about them was reviewed by Greg Moore). Witten gave an overview of his work relating Khovanov homology and QFT, which involves a chain of various 6d, 5d, 4d, 3d and 2d QFTs. Nati Seiberg reviewed the technology used for constructing these theories on various special backgrounds, noting that this was all about “rigid” SUSY theories, with supergravity and string theory making no appearance.
==endquote==
http://www.math.columbia.edu/~woit/wordpress/?p=3811

One can always draw some connection between whatever and something studied in the string program. So presumably one can say that this or that is "string inspired" or "guided by insights from string" if it makes people feel good. As for instance Verlinde tactfully did in the introduction to his Perimeter talk.

Anyway here is the link to Chris Hull's talk which a Strings 2011 conference organizer described as one of the few talks that was actually about string theory.
Hull-- http://media.medfarm.uu.se/flvplayer/strings2011/video16