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2-category 2-category-theory abelian-categories adjoint algebra algebraic algebraic-geometry algebraic-topology analysis analytic-geometry arithmetic arithmetic-geometry beauty bundles calculus categorical categories category category-theory chern-weil-theory cohesion cohesive-homotopy-type-theory cohomology colimits combinatorics complex-geometry computable-mathematics computer-science constructive constructive-mathematics cosmology deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry digraphs duality elliptic-cohomology enriched fibration foundations functional-analysis functor galois-theory gauge-theory gebra geometric-quantization geometry graph graphs gravity grothendieck group 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 integration integration-theory k-theory lie lie-theory limit limits linear linear-algebra locale localization logic mathematics measure measure-theory modal modal-logic model model-category-theory monad monads monoidal monoidal-category-theory morphism motives motivic-cohomology nlab noncommutative noncommutative-geometry number-theory of operads operator operator-algebra order-theory pages pasting philosophy physics 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 string-theory 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 topicmodule spectrum
- Category Latest Changes
- Started by Urs
- Comments 3
- Last comment by Urs
- Last Active Jan 11th 2021

stub for module spectrum. Just the general $\infty$-abstract perspective so far.

- Discussion Type
- discussion topicPeter May
- Category Latest Changes
- Started by Dmitri Pavlov
- Comments 18
- Last comment by Urs
- Last Active Jan 11th 2021

- Discussion Type
- discussion topicRings, modules and algebras in stable homotopy theory
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by Urs
- Last Active Jan 11th 2021

added ISBN:978-0-8218-4303-1

- Discussion Type
- discussion topicsupersymmetric quantum mechanics
- Category Latest Changes
- Started by Urs
- Comments 13
- Last comment by Urs
- Last Active Jan 11th 2021

have created a stub for supersymmetric quantum mechanics

Zoran, I see that you once dropped a big query box at quantum mechanics with a complaint. I disagree with the point you make there: we have fundamental definitions of

*quantum field theory*and restricting them to 1 dimension gives quantum mechanics. If you want to turn this around and understand all QFTs as infinite-dimensional quantum mechanics (which, yes, one can do) you are discarding the nice conceptual models and kill the concept of extended QFT.In any case, I think remarks like this (in the style of “we can also regard this the other way round like this”) are better added into an entry as what they are – remarks – than as query boxes that give the impression that there is something fishy about the rest of the entry.

- Discussion Type
- discussion topicWheeler superspace
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Jan 11th 2021

- Discussion Type
- discussion topicD=2 gravity
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Jan 11th 2021

A stub, to make links work at

*Wheeler superspace*

- Discussion Type
- discussion topicconfiguration space (physics)
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Jan 11th 2021

cross-linked with the example of

*Wheeler superspace*

- Discussion Type
- discussion topiccobordism cohomology theory
- Category Latest Changes
- Started by Urs
- Comments 8
- Last comment by Urs
- Last Active Jan 10th 2021

added pointers on relation of complex cobordism cohomology with divisors, algebraic cycles and Chow groups:

Burt Totaro,

*Torsion algebraic cycles and complex cobordism*, J. Amer. Math. Soc. 10 (1997), 467-493 (doi:10.1090/S0894-0347-97-00232-4)

- Discussion Type
- discussion topicrectangular band
- Category Latest Changes
- Started by Urs
- Comments 8
- Last comment by DavidRoberts
- Last Active Jan 9th 2021

- Discussion Type
- discussion topicbordism homology theory
- Category Latest Changes
- Started by Dmitri Pavlov
- Comments 1
- Last comment by Dmitri Pavlov
- Last Active Jan 9th 2021

- Discussion Type
- discussion topicdistribution
- Category Latest Changes
- Started by Urs
- Comments 5
- Last comment by nLab edit announcer
- Last Active Jan 9th 2021

I found the section-outline of the entry

*distribution*was a bit of a mess. So I have now edited it (just the secion structure, nothing else yet):a) There are now two subsections for “Operations on distributions”,

b) in “Related concepts” I re-titled “Variants” into “Currents” (for that’s what the text is about) and gave “Hyperfunctions and Coulombeau distributions” its own subsection title.

c) split up the References into “General” and “On Coulombeau functions”.

(I hope that this message is regarded as boring and non-controversial.)

- Discussion Type
- discussion topicdistributions are the smooth linear functionals
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by nLab edit announcer
- Last Active Jan 9th 2021

For ease of linking to from various entries, and in order to have all the relevant material in one place, I am creating an entry

Presently this contains

an Idea-section,

some preliminaries to set the scene,

the statement and proof for the case of compactly supported distributions, taken from what I had just writted into the entry

*compactly supported distribution*,the informal statement for general distributions, so far just with a pointer to Kock-Reyes 04,

a section “Applications”, so far with

some comments on the relevance in pQFT;

some vague pointer to Lawvere-Kock’s generalization to a more general theory of “extensive quantity”

both of which deserve to be expanded.

Eventually I want to have more details on the page, but I’ll leave it at that for the time being. Please feel invited to join in.

I’ll go now and add pointers to this page from “distribution” and from other pages that mention the fact.

- Discussion Type
- discussion topicMSU
- Category Latest Changes
- Started by Urs
- Comments 8
- Last comment by Urs
- Last Active Jan 9th 2021

- Discussion Type
- discussion topicbordism ring
- Category Latest Changes
- Started by Urs
- Comments 3
- Last comment by Urs
- Last Active Jan 9th 2021

added brief Properties-section

*Relation to cohomotopy*

- Discussion Type
- discussion topicdistributive category
- Category Latest Changes
- Started by Todd_Trimble
- Comments 25
- Last comment by David_Corfield
- Last Active Jan 9th 2021

Spurred by an MO discussion, I added the observation that coproduct inclusions are monic in a distributive category.

- Discussion Type
- discussion topicdistributive monoidal category
- Category Latest Changes
- Started by Mike Shulman
- Comments 4
- Last comment by Urs
- Last Active Jan 8th 2021

- Discussion Type
- discussion topicthe logic S4(m)
- Category Latest Changes
- Started by nLab edit announcer
- Comments 2
- Last comment by nLab edit announcer
- Last Active Jan 8th 2021

- Discussion Type
- discussion topicsemigroup
- Category Latest Changes
- Started by nLab edit announcer
- Comments 6
- Last comment by Urs
- Last Active Jan 8th 2021

- Discussion Type
- discussion topicfunction monad
- Category Latest Changes
- Started by Urs
- Comments 10
- Last comment by Urs
- Last Active Jan 8th 2021

created a minimum at

*function monad*(aka “reader monad”, “environment monad”)

- Discussion Type
- discussion topicfield
- Category Latest Changes
- Started by Mike Shulman
- Comments 5
- Last comment by Ulrik
- Last Active Jan 8th 2021

I added to field a mention of some other constructive variants of the definition, with a couple more references.

- Discussion Type
- discussion topicShimura variety
- Category Latest Changes
- Started by David_Corfield
- Comments 2
- Last comment by Urs
- Last Active Jan 8th 2021

- Discussion Type
- discussion topicdark matter
- Category Latest Changes
- Started by Urs
- Comments 33
- Last comment by Urs
- Last Active Jan 8th 2021

stub for

*dark matter*

- Discussion Type
- discussion topicone-point compactification intertwines Cartesian product with smash product
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by Urs
- Last Active Jan 8th 2021

am giving this elementary fact its own little stand-alone entry, for ease of hyperlinking at related entries (e.g. at

*one-point compactification*,*pointed topological spaces*,*smash product*,*product topological space*, maybe also at*locally compact Hausdorff space*)

- Discussion Type
- discussion topicrig category
- Category Latest Changes
- Started by Urs
- Comments 17
- Last comment by Urs
- Last Active Jan 8th 2021

concerning the discussion here: notice that an entry

*rig category*had once been created, already.

- Discussion Type
- discussion topicDavid Kazhdan
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by David_Corfield
- Last Active Jan 8th 2021

I have added this quote attributed to Kazhdan:

Physics is very interesting: There are many, many interesting theorems. Unfortunately,there are no definitions.

But does anyone have an authorative reference for this quote?

It’s attributed this way in

Greg Moore, p. 27 of:

*Physical Mathematics and the Future*, 2014 (pdf)

but neither of these gives any further details (such as: “As overheard over coffee break at ABC.” or “As quoted on XYZ’s webpage.”)

- Discussion Type
- discussion topicRobert Langlands
- Category Latest Changes
- Started by David_Corfield
- Comments 1
- Last comment by David_Corfield
- Last Active Jan 8th 2021

Added reference to an article by Langlands.

- Robert Langlands,
*Funktorialität in der Theorie der automorphen Formen: Ihre Entdeckung und ihre Ziele*, in Emil Artin and beyond — class field theory and L-functions, European Math. Soc., 2015, pp. 175–209. Translated by James Milne as*Functoriality in the theory of automorphic forms: its discovery and aims*, (pdf)

- Robert Langlands,

- Discussion Type
- discussion topicMultiset
- Category Latest Changes
- Started by Eric
- Comments 33
- Last comment by edownes
- Last Active Jan 8th 2021

I asked a question on multiset.

If and , is ?

- Discussion Type
- discussion topiccosmic censorship hypothesis
- Category Latest Changes
- Started by Urs
- Comments 8
- Last comment by Urs
- Last Active Jan 8th 2021

I have added to

*cosmic censorship hypothesis*pointer to the recent result (Crisford-Santos 17) showing that it is violated not just in higher dimensions, but also in four spacetime dimensions. And added a minimum of text to go with this. Also cross-linked with*weak gravity conjecture*.

- Discussion Type
- discussion topicDerek Harland
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Jan 8th 2021

- Discussion Type
- discussion topicChris Halcrow
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Jan 8th 2021