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- Discussion Type
- discussion topicSanjaye Ramgoolam
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by Urs
- Last Active Nov 23rd 2019

brief

`category:people`

-entry for hyperlinking references at*Dp-D(p+2)-brane bound states, Yang-Mills monopoles, knot invariants, chord diagrams and fuzzy spheres*.

- Discussion Type
- discussion topicD0-D2 brane bound state
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 23rd 2019

- Discussion Type
- discussion topicD1-D7 brane bound state
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 23rd 2019

a minimum, to give a home to

- Paul Cook, Robert de Mello Koch, Jeff Murugan,
*Non-Abelian BIonic Brane Intersections*, Phys. Rev. D68:126007, 2003 (arXiv:hep-th/0306250)

on D1-D7 brane intersections as fuzzy funnels on fuzzy 6-spheres

- Paul Cook, Robert de Mello Koch, Jeff Murugan,

- Discussion Type
- discussion topicNeil Constable
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 23rd 2019

brief

`category:people`

-entry for hyperlinking references at*fuzzy funnel*,*D1-D3 brane intersection*,*D1-D5 brane intersection*

- Discussion Type
- discussion topicPaul Koerber
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 23rd 2019

brief

`category:people`

-entry for hyperlinking references at*generalized complex geometry*and*G-structure*

- Discussion Type
- discussion topicG-structure
- Category Latest Changes
- Started by zskoda
- Comments 20
- Last comment by Urs
- Last Active Nov 23rd 2019

I do not understand the entry G-structure. G-structure is, as usual, defined there as the principal $G$-subbundle of the frame bundle which is a $GL(n)$-principal bundle. I guess this makes sense for equivariant injections along any Lie group homomorphism $G\to GL(n)$. The entry says something about spin structure, warning that the group $Spin(n)$ is not a subgroup of $GL(n)$. So what is meant ? The total space of a subbundle is a subspace at least. Does this mean that I consider the frame bundle first as a (non-principal) $Spin(n)$-bundle by pulling back along a fixed noninjective map $Spin(n)\to GL(n)$ and then I restrict to a chosen subspace on which the induced action of Spin group is principal ?

- Discussion Type
- discussion topicgeneralized complex geometry
- Category Latest Changes
- Started by Urs
- Comments 5
- Last comment by Urs
- Last Active Nov 23rd 2019

I am working on entries related to generalized complex geometry. My aim is to tell the story in the correct way as the theory of the

*Lie 2-algebroid*called theMost, if not all, of the generalized complex geometry literature, uses the "naive" definition of Courant algebroids that regards them as vector bundles with some structure on them and is being vague to ignorant about what the right morphisms should be.

As discussed at Courant algebroid we know that we are really dealing with a Lie 2-algebroid and hence know where precisely this object lives. This provides some useful, I think, perspectives on some of the standard constructions. I want to eventually describe this. For the moment I have just the material at standard Courant algebroid with only two most basic observations (which, however, in my experience already take a nontrivial amount of time on the blackboard to explain to somebody used to the "naive" picture usually presented in the literature).

- Discussion Type
- discussion topicJérôme Gaillard
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 23rd 2019

brief

`category:people`

-entry for hyperlinking references at*G-structure*and at*holographic QCD*(if anyone has a webpage for this author, let’s add the URL)

- Discussion Type
- discussion topicspecial holonomy
- Category Latest Changes
- Started by Urs
- Comments 4
- Last comment by Urs
- Last Active Nov 23rd 2019

stub for special holonomy, just to record two references for the moment.

Also added a line to the Idea-section at holonomy that mentions holonomy group and special holonomy.

- Discussion Type
- discussion topiccotensor product
- Category Latest Changes
- Started by Urs
- Comments 7
- Last comment by Mike Shulman
- Last Active Nov 22nd 2019

I have added to

*cotensor product*a section, here, with some basics on cotensor products of comodules over commutative Hopf algebroids. The same stuff I have added also in the respective section at*commutative Hopf algebroid*

- Discussion Type
- discussion topicHo(Cat)
- Category Latest Changes
- Started by Mike Shulman
- Comments 11
- Last comment by Mike Shulman
- Last Active Nov 22nd 2019

Created Ho(Cat), mainly as a place to put a counterexample showing that it doesn't have pullbacks. If anyone has a simpler one, please contribute it.

- Discussion Type
- discussion topicderived Morita equivalence
- Category Latest Changes
- Started by David_Corfield
- Comments 5
- Last comment by zskoda
- Last Active Nov 22nd 2019

I added to duality in physics a reference to a form of mirror symmetry being a derived Morita equivalence. So also created a stub for derived Morita equivalence.

- Discussion Type
- discussion topicMorita equivalence
- Category Latest Changes
- Started by Thomas Holder
- Comments 9
- Last comment by zskoda
- Last Active Nov 22nd 2019

This is intended to continue the issues discussed in the Lafforgue thread!

I have added an idea section to Morita equivalence where I sketch what I perceive to be the overarching pattern stressing in particular the two completion processes involved. I worked with ’hyphens’ there but judging from a look in Street’s quantum group book the pattern can be spelled out exactly at a bicategorical level.

I might occasionally add further material on the Morita theory for algebraic theories where especially the book by Adamek-Rosicky-Vitale (pdf-draft) contains a general 2-categorical theorem for algebraic theories.

Another thing that always intrigued me is the connection with shape theory where there is a result from Betti that the endomorphism module involved in ring Morita theory occurs as the shape category of a ring morphism in the sense of Bourn-Cordier. Another thing worth mentioning on the page is that the Cauchy completion of a ring in the enriched sense is actually its cat of modules (this is in Borceux-Dejean) - this brings out the parallel between Morita for cats and rings.

- Discussion Type
- discussion topicMorita context
- Category Latest Changes
- Started by zskoda
- Comments 2
- Last comment by zskoda
- Last Active Nov 22nd 2019

Morita context in works!

- Discussion Type
- discussion topicinduced comodule
- Category Latest Changes
- Started by zskoda
- Comments 1
- Last comment by zskoda
- Last Active Nov 22nd 2019

- Discussion Type
- discussion topicopetope
- Category Latest Changes
- Started by Urs
- Comments 3
- Last comment by nLab edit announcer
- Last Active Nov 22nd 2019

some trivial edits to opetope (a toc, some hyperlinks)

- Discussion Type
- discussion topicentanglement entropy
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by Urs
- Last Active Nov 22nd 2019

added pointer to today’s

- Matthew Headrick,
*Lectures on entanglement entropy in field theory and holography*(arXiv:1907.08126)

- Matthew Headrick,

- Discussion Type
- discussion topicD=2 QCD
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by Urs
- Last Active Nov 22nd 2019

- Discussion Type
- discussion topic!-modality
- Category Latest Changes
- Started by Urs
- Comments 17
- Last comment by Mike Shulman
- Last Active Nov 21st 2019

collected some references on the interpretation of the !-modality as the Fock space construction at

*!-modality*.Cross-linked briefly with he stub entries_Fock space_ and

*second quantization*.

- Discussion Type
- discussion topicChu construction
- Category Latest Changes
- Started by Mike Shulman
- Comments 4
- Last comment by nLab edit announcer
- Last Active Nov 21st 2019

- Discussion Type
- discussion topiccircle n-group
- Category Latest Changes
- Started by Urs
- Comments 4
- Last comment by Ali Caglayan
- Last Active Nov 21st 2019

felt the need to split off a separate entry for circle n-group

- Discussion Type
- discussion topicAdS3-CFT2 and CS-WZW correspondence
- Category Latest Changes
- Started by Urs
- Comments 6
- Last comment by Urs
- Last Active Nov 21st 2019

I have split off from

*holographic principle*and then expanded a good bit a few paragraphs on*AdS3-CFT2 and CS-WZW correspondence*together with a few commented references, trying to amplify how this case is given by an actual well-known theorem and at the same time seems to be generic for the more general cases of AdS-CFT which are currently much more vague.

- Discussion Type
- discussion topicNicholas Warner
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Nov 21st 2019

brief

`category:people`

-entry for hyperlinking references at*G-structure*,*M-theory on Spin(7)-manifolds*,*Landau-Ginzburg model*,*D=5 supergravity*

- Discussion Type
- discussion topicBFSS matrix model
- Category Latest Changes
- Started by Urs
- Comments 17
- Last comment by Urs
- Last Active Nov 20th 2019

- Discussion Type
- discussion topicanti de Sitter spacetime
- Category Latest Changes
- Started by Urs
- Comments 7
- Last comment by Urs
- Last Active Nov 20th 2019

earlier today I had created a stub for anti de Sitter spacetime

- Discussion Type
- discussion topicmassive type IIA string theory
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by Urs
- Last Active Nov 20th 2019

- Discussion Type
- discussion topiccubical type theory
- Category Latest Changes
- Started by Urs
- Comments 15
- Last comment by AlexisHazell
- Last Active Nov 20th 2019

started

*cubical type theory*using a comment by Jonathan Sterling

- Discussion Type
- discussion topicflavour (particle physics)
- Category Latest Changes
- Started by Urs
- Comments 8
- Last comment by Urs
- Last Active Nov 20th 2019

- Discussion Type
- discussion topicAdS-QCD correspondence
- Category Latest Changes
- Started by Urs
- Comments 26
- Last comment by Urs
- Last Active Nov 20th 2019

- Discussion Type
- discussion topic3d-3d correspondence
- Category Latest Changes
- Started by Urs
- Comments 8
- Last comment by Urs
- Last Active Nov 20th 2019