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- Discussion Type
- discussion topicadditive category
- Category Latest Changes
- Started by Urs
- Comments 15
- Last comment by Todd_Trimble
- Last Active Jul 30th 2019

touched the formatting at

*additive category*

- Discussion Type
- discussion topicEvgeny Likhtman
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Jul 30th 2019

brief

`category:people`

-entry for hyperlinking references at*super Poincaré Lie algebra*and*supersymmetry*

- Discussion Type
- discussion topicYuri Golfand
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Jul 30th 2019

brief

`category:people`

-entry for hypoerlinking references at*super Poincaré Lie algebra*and*supersymmetry*

- Discussion Type
- discussion topicsupersymmetry
- Category Latest Changes
- Started by Urs
- Comments 42
- Last comment by Urs
- Last Active Jul 30th 2019

I’ll be working a bit on supersymmetry.

Zoran, you had once left two query boxes there with complaints. The second one is after this bit of the original entry (this will change any minute now)

The theory of supergravity is, as a classical field theory, an action functional on functions on a supermanifold $X$ which is invariant under the super-diffeomorphism group of $X$.

where you say

Zoran: action functional is on paths, even paths in infinitedimensional space, but not on point-functions.

I think you got something mixed up here. If $X$ is spacetime, a field on $X$

*is*the “path” that you want to see. The statement as given is correct, but I’ll try to expand on it.The second complaint is after where the original entry said

many models that suggest that the familiar symmetry of various action functionals should be enhanced to a supersymmetry in order to more properly describe fundamental physics.

You wrote:

This is doubtful and speculative. There are many models which have supersymmetry which is useful in their theoretical analysis, but the same models can be treated in formalisms not knowing about supersymmetry. Wheather the fundamental physics needs a model which has nontrivial supersymmetry is a speculative statement, and I disagree with equating theoretical physics with one direction in “fundamental physics”. I do not understand how can a model suggest supersymmetry; it is rather experimental evidence or problems with nonsupersymmetric models. Also one should distinguish the supersymmetry at the level of Lagrangean and the supersymmetry which holds only for each solution of the equation of motion.

I’ll rephrase the original statement to something less optimistic, but i do think that supersymmetry is suggsted more by looking at the formal nature of models than by lookin at the nature of nature. If you have a gauge theory for some Lie algebra (gravity, Poincaré Lie algebra) and the super extension of the Lie algebra has an interesting classification theory (the super Poincar´ algebra) then it is more th formalist in us who tends to feel compelled to investigate this than the phenomenologist. Supersymmetry is studied so much because it looks compelling on paper. Not because we have compelling phenomenological evidence. On the contrary.

So, if you don’t mind, I will remove both your query boxes and slightly polish the entry. Let’s have any further discussion here.

- Discussion Type
- discussion topicThe many faces of the superworld
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Jul 30th 2019

brief

`category:reference`

-entry for hyperlinkingMikhail Shifman (ed.)

*The Many Faces of the Superworld*Yuri Golfand memorial volume

World Scientific, 2000

- Discussion Type
- discussion topicdouble gluing
- Category Latest Changes
- Started by Sam Staton
- Comments 5
- Last comment by Sam Staton
- Last Active Jul 30th 2019

- Discussion Type
- discussion topicspecies
- Category Latest Changes
- Started by nLab edit announcer
- Comments 3
- Last comment by Todd_Trimble
- Last Active Jul 29th 2019

- Discussion Type
- discussion topicquantum probability theory
- Category Latest Changes
- Started by Urs
- Comments 23
- Last comment by David_Corfield
- Last Active Jul 29th 2019

I started a bare minimum at

*quantum probability*(redirecting*noncommutative probability space*etc.)Some entries have long been secretly referencing such an entry, and I have cross-linked accordingly, for instance from

*von Neumann algebra*and*quantum computing*.I had the feeling somewhere we already had a detailed account of probability theory dually in terms of von NNeumann algebras, but if we do I didn’t find it(?)

- Discussion Type
- discussion topiclists of journals
- Category Latest Changes
- Started by Mike Shulman
- Comments 20
- Last comment by Dmitri Pavlov
- Last Active Jul 29th 2019

- Discussion Type
- discussion topicmatroid
- Category Latest Changes
- Started by Todd_Trimble
- Comments 10
- Last comment by nLab edit announcer
- Last Active Jul 29th 2019

I have been adding some material to matroid. I haven’t gotten around to defining oriented matroid yet (and of course there’s much besides to add).

- Discussion Type
- discussion topicBohr topos
- Category Latest Changes
- Started by Urs
- Comments 11
- Last comment by Urs
- Last Active Jul 29th 2019

expanded the section

*Idea – In brief*at*Bohr topos*just a little bit, in order to amplify the relation to Jordan algebras better (which previously was a bit hidden in entry).

- Discussion Type
- discussion topicKochen-Specker theorem
- Category Latest Changes
- Started by Ian_Durham
- Comments 17
- Last comment by Urs
- Last Active Jul 29th 2019

Since no one objected to my offer, I started a stub for the Kochen-Specker theorem and will continue working on it a bit later.

- Discussion Type
- discussion topicarity space
- Category Latest Changes
- Started by Mike Shulman
- Comments 9
- Last comment by Sam Staton
- Last Active Jul 29th 2019

- Discussion Type
- discussion topicFrames and Locales
- Category Latest Changes
- Started by Dmitri Pavlov
- Comments 1
- Last comment by Dmitri Pavlov
- Last Active Jul 28th 2019

- Discussion Type
- discussion topicMehrnoosh Sadrzadeh
- Category Latest Changes
- Started by Tim_Porter
- Comments 1
- Last comment by Tim_Porter
- Last Active Jul 28th 2019

- Discussion Type
- discussion topicdouble category
- Category Latest Changes
- Started by John Baez
- Comments 7
- Last comment by nLab edit announcer
- Last Active Jul 28th 2019

- I added more info on pseudo double categories and double bicategories to double category. I also simplified the picture of a square, which had been bristling with scary unnecessary detail. There's a slight blemish in the left vertical arrow, which I can't see how to fix.

- Discussion Type
- discussion topicexceptional generalized geometry
- Category Latest Changes
- Started by Urs
- Comments 5
- Last comment by Urs
- Last Active Jul 28th 2019

added to

*exceptional generalized geometry*two examples of reductions of stucture groups that encode higher supersymmetry in 11d sugra.

- Discussion Type
- discussion topicribbon category
- Category Latest Changes
- Started by nLab edit announcer
- Comments 4
- Last comment by John Baez
- Last Active Jul 28th 2019

- Discussion Type
- discussion topicBoolean locale
- Category Latest Changes
- Started by Dmitri Pavlov
- Comments 8
- Last comment by Mike Shulman
- Last Active Jul 27th 2019

- Discussion Type
- discussion topicE11
- Category Latest Changes
- Started by Urs
- Comments 7
- Last comment by Urs
- Last Active Jul 27th 2019

have added a minimum on the level decompositon of the first fundamental rep of $E_{11}$ here.

- Discussion Type
- discussion topicM2-brane
- Category Latest Changes
- Started by Urs
- Comments 5
- Last comment by Urs
- Last Active Jul 27th 2019

added a bunch of references to

*M2-brane*

- Discussion Type
- discussion topicsuperstring
- Category Latest Changes
- Started by Urs
- Comments 3
- Last comment by Urs
- Last Active Jul 27th 2019

for completeness, I have splitt off superstring from string

- Discussion Type
- discussion topicinfinity-group
- Category Latest Changes
- Started by nLab edit announcer
- Comments 2
- Last comment by nLab edit announcer
- Last Active Jul 27th 2019

- Discussion Type
- discussion topicstandard model of cosmology
- Category Latest Changes
- Started by Urs
- Comments 9
- Last comment by Urs
- Last Active Jul 27th 2019

added this, under References – Review:

- V.F. Mukhanov,
*Quantum Universe*, Phys.Usp. 59 (2016) no.10, 1021-1027 (spire:1507528, doi:10.3367/UFNe.2016.07.037857)

In March 2013, following an accurate processing of available measurement data, the Planck Scientific Collaboration published the highest-resolution photograph ever of the early Universe when it was only a few hundred thousand years old. The photograph showed galactic seeds in sufficient detail to test some nontrivial theoretical predictions made more than thirty years ago. Most amazing was that all predictions were confirmed to be remarkably accurate. With no exaggeration, we may consider it established experimentally that quantum physics, which is normally assumed to be relevant on the atomic and subatomic scale, also works on the scale of the entire Universe, determining its structure with all its galaxies, stars, and planets.

- V.F. Mukhanov,

- Discussion Type
- discussion topicself-dual higher gauge theory
- Category Latest Changes
- Started by Urs
- Comments 4
- Last comment by Urs
- Last Active Jul 27th 2019

started self-dual higher gauge theory. Just minimal idea and list of references so far.

- Discussion Type
- discussion topicDmitrij Volkov
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Jul 27th 2019

added a bunch of further links, and made

*Dmitry Volkov*a redirect

- Discussion Type
- discussion topicpretopos
- Category Latest Changes
- Started by Mike Shulman
- Comments 7
- Last comment by David_Corfield
- Last Active Jul 26th 2019

I have incorporated Jonas’ comment into the text at pretopos, changing the definition to “a category that is both exact and extensive”, as this is sufficient to imply that it is both regular and coherent.

- Discussion Type
- discussion topicSimon Cho
- Category Latest Changes
- Started by David_Corfield
- Comments 1
- Last comment by David_Corfield
- Last Active Jul 26th 2019

- Discussion Type
- discussion topicclassical r-matrix
- Category Latest Changes
- Started by nLab edit announcer
- Comments 1
- Last comment by nLab edit announcer
- Last Active Jul 25th 2019

- Discussion Type
- discussion topicquantum Yang-Baxter matrix
- Category Latest Changes
- Started by nLab edit announcer
- Comments 2
- Last comment by nLab edit announcer
- Last Active Jul 25th 2019