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2-categories 2-category 2-category-theory abelian-categories adjoint algebra algebraic algebraic-geometry algebraic-topology analysis analytic-geometry arithmetic arithmetic-geometry beauty bundles calculus categories category category-theory chern-weil-theory cohesion cohesive-homotopy-type-theory cohomology combinatorics complex-geometry computable-mathematics computer-science connection constructive constructive-mathematics cosmology deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry differential-topology digraphs duality education elliptic-cohomology enriched fibration finite foundations functional-analysis functor galois-theory gauge-theory gebra geometric-quantization geometry graph graphs gravity grothendieck group-theory harmonic-analysis higher higher-algebra higher-category-theory higher-differential-geometry higher-geometry higher-lie-theory higher-topos-theory homological homological-algebra homotopy homotopy-theory homotopy-type-theory index-theory infinity integration integration-theory k-theory lie lie-theory limits linear linear-algebra locale localization logic manifolds mathematics measure-theory modal-logic model model-category-theory monad monoidal monoidal-category-theory morphism motives motivic-cohomology multicategories noncommutative noncommutative-geometry number-theory of operads operator operator-algebra order-theory pasting philosophy physics planar pro-object probability probability-theory quantization quantum quantum-field quantum-field-theory quantum-mechanics quantum-physics quantum-theory question representation representation-theory riemannian-geometry scheme schemes set set-theory sheaf simplicial space spin-geometry stable-homotopy-theory stack string-theory subobject superalgebra supergeometry svg symplectic-geometry synthetic-differential-geometry terminology theory topology topos topos-theory type type-theory universal variational-calculus

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- Discussion Type
- discussion topicErlangen program
- Category Latest Changes
- Started by Urs
- Comments 11
- Last comment by David_Corfield
- Last Active May 17th 2019

I have touched a bunch of the entries related to the

*Erlangen program*, trying to polish a bit, adding more cross links and more references.(This includes the entries

*stabilizer group*,*coset*,*Klein geometry*,*Cartan geometry*and maybe more.)

- Discussion Type
- discussion topicpin group
- Category Latest Changes
- Started by Urs
- Comments 4
- Last comment by DavidRoberts
- Last Active May 16th 2019

- Discussion Type
- discussion topicmodal type theory
- Category Latest Changes
- Started by Urs
- Comments 85
- Last comment by Urs
- Last Active May 16th 2019

created an entry

*modal type theory*; tried to collect pointers I could find to articles which discuss the interpretation of modalities in terms of (co)monads. I was expecting to find much less, but there are a whole lot of articles discussing this. Also cross-linked with*monad (in computer science)*.

- Discussion Type
- discussion topicElmendorf's theorem
- Category Latest Changes
- Started by Urs
- Comments 13
- Last comment by Urs
- Last Active May 16th 2019

started

*Elmendorf’s theorem*with a brief statement of the theorem

- Discussion Type
- discussion topicinductive-inductive type
- Category Latest Changes
- Started by nLab edit announcer
- Comments 3
- Last comment by spitters
- Last Active May 16th 2019

- Discussion Type
- discussion topiccentral product of groups
- Category Latest Changes
- Started by Urs
- Comments 3
- Last comment by Urs
- Last Active May 16th 2019

some minimum, for cross-linking with Sp(n).Sp(1)

- Discussion Type
- discussion topicRoger Penrose
- Category Latest Changes
- Started by Urs
- Comments 4
- Last comment by Urs
- Last Active May 16th 2019

added some actual text to the category:people entry

*Roger Penrose*

- Discussion Type
- discussion topicover-topos
- Category Latest Changes
- Started by Urs
- Comments 15
- Last comment by Urs
- Last Active May 16th 2019

created over-topos

- Discussion Type
- discussion topicmind
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active May 16th 2019

just a stub, to make a link from the entry

*Roger Penrose*work,

- Discussion Type
- discussion topictorsion theory
- Category Latest Changes
- Started by nLab edit announcer
- Comments 2
- Last comment by Urs
- Last Active May 16th 2019

- Discussion Type
- discussion topicChris Doran
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active May 16th 2019

brief

`category:people`

-entry for hyperlinking references at*geometric algebra*

- Discussion Type
- discussion topicgeometric algebra
- Category Latest Changes
- Started by Urs
- Comments 7
- Last comment by Urs
- Last Active May 16th 2019

gave

*geometric algebra*an Idea-section

- Discussion Type
- discussion topicorientifold
- Category Latest Changes
- Started by Urs
- Comments 7
- Last comment by Urs
- Last Active May 16th 2019

added to orientifold some basic notions on orientifold circle $n$-bundles.

- Discussion Type
- discussion topicGalois cohomology
- Category Latest Changes
- Started by Urs
- Comments 23
- Last comment by DavidRoberts
- Last Active May 16th 2019

started

*Galois cohomology*

- Discussion Type
- discussion topicSpin(16)
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active May 15th 2019

stub, for the moment just so as to fill the pattern at

*low dimensional rotation groups – table*

- Discussion Type
- discussion topicSpin(32)
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active May 15th 2019

stub, for the moment just so as to fill the pattern at

*low dimensional rotation groups – table*

- Discussion Type
- discussion topicSO(32)
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active May 15th 2019

stub (except for a brief remark on this being the gauge group in type I ST), for the moment just to fill the pattern at

*low dimensional rotation groups – table*

- Discussion Type
- discussion topicSO(16)
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active May 15th 2019

stub, for the moment just to fill the pattern at

*low dimensional rotation groups – table*

- Discussion Type
- discussion topiclow dimensional rotation groups -- table
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by Urs
- Last Active May 15th 2019

- Discussion Type
- discussion topicorientifold plane
- Category Latest Changes
- Started by Urs
- Comments 5
- Last comment by Urs
- Last Active May 15th 2019

slightly expanded the section Duality with M-theory, mentioning more of the MO-planes and giving more pointers

- Discussion Type
- discussion topicstring theory
- Category Latest Changes
- Started by Urs
- Comments 8
- Last comment by Urs
- Last Active May 15th 2019

I have added to string theory a new section Critical strings and quantum anomalies.

Really I was beginning to work on a new entry twisted spin^c structure (not done yet) and then I found that a summary discussion along the above lines had been missing.

- Discussion Type
- discussion topicexceptional structures -- contents
- Category Latest Changes
- Started by Urs
- Comments 6
- Last comment by Urs
- Last Active May 15th 2019

- Discussion Type
- discussion topicduality between M-theory and F-theory
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active May 15th 2019

just for completeness of the pattern at

*duality in string theory – contents*I am splittng this here off as a stand-alone entry. Currently this contains nothing but a copy of the first bits from the entry*F-theory*

- Discussion Type
- discussion topicduality between type I and heterotic string theory
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active May 15th 2019

this used to lazily redirect to

*Hořava-Witten theory*am splitting it off now to, eventually, do it more justice. But just a stub for the time being

- Discussion Type
- discussion topicStarobinsky model of cosmic inflation
- Category Latest Changes
- Started by Urs
- Comments 13
- Last comment by Urs
- Last Active May 15th 2019

- Discussion Type
- discussion topicFrancesco Toppan
- Category Latest Changes
- Started by David_Corfield
- Comments 1
- Last comment by David_Corfield
- Last Active May 15th 2019

- Discussion Type
- discussion topicprojective line
- Category Latest Changes
- Started by Mike Shulman
- Comments 4
- Last comment by DavidRoberts
- Last Active May 15th 2019

I added a synthetic definition to projective line, which I learned from here. However, I’m still trying to understand the terminology used; and, as I remarked, with my current understanding the definition doesn’t seem right.

- Discussion Type
- discussion topicHowTo
- Category Latest Changes
- Started by Urs
- Comments 37
- Last comment by Daniel Luckhardt
- Last Active May 14th 2019

Have added to HowTo a description for how to label equations

In the course of this I restructured the section “How to make links to subsections of a page” by giving it a few descriptively-titled subsections.

- Discussion Type
- discussion topic(sub)object classifier in an (infinity,1)-topos
- Category Latest Changes
- Started by David_Corfield
- Comments 8
- Last comment by David_Corfield
- Last Active May 14th 2019

- Discussion Type
- discussion topicWigner theorem
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by Urs
- Last Active May 14th 2019

added pointer to

- Valentine Bargman,
*Note on Wigner’s theorem on symmetry transformations*, Journal of Mathematical Physics 5.7 (1964): 862-868 (doi:10.1063/1.1704188)

- Valentine Bargman,