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- Discussion Type
- discussion topictwisted differential cohomology
- Category Latest Changes
- Started by Urs
- Comments 6
- Last comment by Urs
- Last Active Jul 23rd 2019

created a stub for

*twisted differential cohomology*and cross-linked a bit.This for the moment just to record the existence of

- Ulrich Bunke, Thomas Nikolaus,
*Twisted differential cohomology*(arXiv:1406.3231)

No time right now for more. But later.

- Ulrich Bunke, Thomas Nikolaus,

- Discussion Type
- discussion topictwisted differential K-theory
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Jul 23rd 2019

added some lines on the relation to D-brane charge (spun off from additions I just made to

*twisted differential cohomoloy*), and added more references

- Discussion Type
- discussion topicHurewicz cofibration
- Category Latest Changes
- Started by DavidRoberts
- Comments 1
- Last comment by DavidRoberts
- Last Active Jul 23rd 2019

Gave proper reference for (Kieboom 1987).

- Discussion Type
- discussion topicfiniteness space
- Category Latest Changes
- Started by Mike Shulman
- Comments 5
- Last comment by Mike Shulman
- Last Active Jul 22nd 2019

- Discussion Type
- discussion topicNovikov field
- Category Latest Changes
- Started by Mike Shulman
- Comments 7
- Last comment by nLab edit announcer
- Last Active Jul 22nd 2019

Created page about Novikov fields, another kind of generalized power series field. I’m looking for a good notation for these along the lines of $k[[x]]$ for power series rings, $k((x))$ for Laurent series fields, $k((x^G))$ for Hahn series fields; the only notation in the literature seems to be $\Lambda(k)$, which doesn’t suggest its meaning to me and clashes with exterior algebras.

- Discussion Type
- discussion topicsvelte category
- Category Latest Changes
- Started by Mike Shulman
- Comments 1
- Last comment by Mike Shulman
- Last Active Jul 22nd 2019

I just noticed this page. Is it really worth having separately from essentially small category (which redirects to small category)?

- Discussion Type
- discussion topiclens (in computer science)
- Category Latest Changes
- Started by David_Corfield
- Comments 7
- Last comment by nLab edit announcer
- Last Active Jul 22nd 2019

- Discussion Type
- discussion topicRibenboim power series
- Category Latest Changes
- Started by Mike Shulman
- Comments 1
- Last comment by Mike Shulman
- Last Active Jul 22nd 2019

- Discussion Type
- discussion topicquantization via the A-model
- Category Latest Changes
- Started by nLab edit announcer
- Comments 2
- Last comment by nLab edit announcer
- Last Active Jul 22nd 2019

- Discussion Type
- discussion topicD=4 N=2 super Yang-Mills theory
- Category Latest Changes
- Started by Urs
- Comments 12
- Last comment by Urs
- Last Active Jul 22nd 2019

created stub for

*N=2 D=4 super Yang-Mills theory*…… for the moment mainly such as to be able to make

*Coulomb branch*and*Higgs branch*redirect to it, which are needed at*symplectic duality*

- Discussion Type
- discussion topichomotopy limit
- Category Latest Changes
- Started by DavidRoberts
- Comments 1
- Last comment by DavidRoberts
- Last Active Jul 22nd 2019

- Discussion Type
- discussion topicvan Kampen theorem
- Category Latest Changes
- Started by Urs
- Comments 4
- Last comment by DavidRoberts
- Last Active Jul 22nd 2019

added to van Kampen theorem a clean statement for the group-version

- Discussion Type
- discussion topicD=7 supergravity
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by Urs
- Last Active Jul 22nd 2019

added these pointers

Discussion of quantum anomaly cancellation and 7d Horava-Witten theory is in

{#GherghettaKehagias02} Tony Gherghetta, Alex Kehagias,

*Anomaly Cancellation in Seven-Dimensional Supergravity with a Boundary*, Phys.Rev.**D68**(2003), 065019, (arXiv:hep-th/0212060)Spyros D. Avramis, Alex Kehagias, _Gauged $D=7$ Supergravity on the $S^1/\mathbb{Z}_2$ Orbifold (arXiv:hep-th/0407221)

T.G. Pugh, Ergin Sezgin, Kellogg Stelle,

*$D=7$ / $D=6$ Heterotic Supergravity with Gauged R-Symmetry*(arXiv:1008.0726)

- Discussion Type
- discussion topicStarobinsky model of cosmic inflation
- Category Latest Changes
- Started by Urs
- Comments 14
- Last comment by Urs
- Last Active Jul 22nd 2019

- Discussion Type
- discussion topiclinear logic
- Category Latest Changes
- Started by Mike Shulman
- Comments 8
- Last comment by nLab edit announcer
- Last Active Jul 21st 2019

The cut rule for linear logic used to be stated as

If $\Gamma \vdash A$ and $A \vdash \Delta$, then $\Gamma \vdash \Delta$.

I don’t think this is general enough, so I corrected it to

If $\Gamma \vdash A, \Phi$ and $\Psi,A \vdash \Delta$, then $\Psi,\Gamma \vdash \Delta,\Phi$.

- Discussion Type
- discussion topic!-modality
- Category Latest Changes
- Started by Urs
- Comments 9
- Last comment by nLab edit announcer
- Last Active Jul 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 topicgraviphoton
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Jul 21st 2019

- Discussion Type
- discussion topicstructured cospan
- Category Latest Changes
- Started by nLab edit announcer
- Comments 9
- Last comment by Urs
- Last Active Jul 21st 2019

This is my first (substantial) contribution to the nLab, so forgive my likely ineptitude. This wants to be a initial stub, everything is basically scraped from the reference and this post: https://golem.ph.utexas.edu/category/2019/07/structured_cospans.html Clearly a lot of material can be added, included a better definition and clearer examples. It’s also quite necessary to make a page for decorated cospans. I might start it myself later this month.

mattecapu

- Discussion Type
- discussion topicdecorated cospan
- Category Latest Changes
- Started by nLab edit announcer
- Comments 2
- Last comment by nLab edit announcer
- Last Active Jul 21st 2019

- Discussion Type
- discussion topicsimplicial homotopy
- Category Latest Changes
- Started by Tim_Porter
- Comments 4
- Last comment by Tobias Fritz
- Last Active Jul 20th 2019

Someone anonymous (probably from Gottingen) had changed simplicial homotopy. The old version seems to have had a different convention on the ordeing of the parts which was not ’wrong’ but was slightly different from some sources. I have added a note to the entry pointing out the existence of different conventions, and have cleaned up the use of $\Delta^n$ instead of the more usual $\Delta[n]$ in that entry.

I checked back in the linked entry simplex, there, and found that the entry was a bit confusing as to the simplicial set $\Delta[n]$. I have altered the structure and wording slightly to clarify things (I hope).

- Discussion Type
- discussion topicRan space
- Category Latest Changes
- Started by DavidRoberts
- Comments 15
- Last comment by nLab edit announcer
- Last Active Jul 19th 2019

I put in a reference to Lurie’s course on Tamagawa numbers at Ran space.

- Discussion Type
- discussion topicentanglement entropy
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Jul 19th 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 topicsemidirect product group
- Category Latest Changes
- Started by nLab edit announcer
- Comments 2
- Last comment by Urs
- Last Active Jul 19th 2019

- Discussion Type
- discussion topicopen/closed string duality
- Category Latest Changes
- Started by nLab edit announcer
- Comments 2
- Last comment by Urs
- Last Active Jul 18th 2019

- Discussion Type
- discussion topicessentially algebraic theory
- Category Latest Changes
- Started by Urs
- Comments 5
- Last comment by David_Corfield
- Last Active Jul 18th 2019

added references to

*essentially algebraic theory*. Also equipped the text with a few more hyperlinks.

- Discussion Type
- discussion topicMealy machine
- Category Latest Changes
- Started by Tim_Porter
- Comments 8
- Last comment by Tim_Porter
- Last Active Jul 18th 2019

Idem for Mealy machines to link with Mealy morphism

- Discussion Type
- discussion topiccoalgebra for an endofunctor
- Category Latest Changes
- Started by Urs
- Comments 9
- Last comment by Tim_Porter
- Last Active Jul 18th 2019

added to coalgebra for an endofunctor the example of the real line as the terminal coalgebra for some endofunctor on Posets.

There are more such characterizations of the real line, and similar. I can't dig them out right now as I am on a shky connection. But maybe somebody else can. Or I'll do it later.

- Discussion Type
- discussion topicDirk Pattinson
- Category Latest Changes
- Started by Tim_Porter
- Comments 1
- Last comment by Tim_Porter
- Last Active Jul 18th 2019

- Discussion Type
- discussion topicMealy morphism
- Category Latest Changes
- Started by nLab edit announcer
- Comments 8
- Last comment by Tim_Porter
- Last Active Jul 18th 2019

- Discussion Type
- discussion topicMoore machine
- Category Latest Changes
- Started by Tim_Porter
- Comments 2
- Last comment by Tim_Porter
- Last Active Jul 18th 2019