Not signed in (Sign In)

Not signed in

Want to take part in these discussions? Sign in if you have an account, or apply for one below

  • Sign in using OpenID

Site Tag Cloud

2-category 2-category-theory abelian-categories adjoint algebra algebraic algebraic-geometry algebraic-topology analysis analytic-geometry arithmetic arithmetic-geometry book bundles calculus categorical categories category category-theory chern-weil-theory cohesion cohesive-homotopy-type-theory cohomology colimits combinatorics comma complex complex-geometry computable-mathematics computer-science constructive cosmology deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry digraphs duality elliptic-cohomology enriched fibration finite foundation foundations functional-analysis functor 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-theory limits linear linear-algebra locale localization logic mathematics 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 tqft type type-theory universal variational-calculus

Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to nForum
If you want to take part in these discussions either sign in now (if you have an account), apply for one now (if you don't).
    • Added in the formula giving the associated crossed complex from the Moore complex of the simplicial group(oid).

      diff, v9, current

    • Because of the algebraic Kan complex entry I had a look at the simplicial T-complex page. I am not sure that the current page is quite right in its wording. It is a bit the age old problem of structure or properties. In the algebraic Kan complex, the filler choice function is part of the structure. In a T-complex the thin elements form part of the structure but then properties of the thin elements show that there is a unique choice function taking thin values. They then satisfy some equational conditions.

      My thought would be that there should be a bit more precision on the differences between them. For instance I think it is true (but I would need to prove it in detail) that any simplicial T-complex gave an algebraic Kan complex, yielding an ’inclusion functor’ from SimpT to Alg Kan. That functor should have a left adjoint which kills off the Whitehead products etc, (that need not be trivial for an algebraic Kan complex but are for a simplicial T-complex). I do not see how to construct this explicitly but am sure there must be a simple way of imposing conditions on an alg. Kan complex and looking at ’varieties’ in that category. (I have not read Thomas’s thesis and he may have done something related to this already.) In other words, can one impose equations on alg. Kan complexes, in this way. The present definition is more or less the free algebras case (?).

      Before altering the simp. T-complex page, I thought it worth asking this question of ’varieties’ as the answer (if it is known) would influence how best to do the edit.

    • Thomas's guest post at cafe and his paper should maybe be reflected in entry infinity-category and other places in nlab where various "models" fro infinity categories are listed, as it should have a very important role in my opinion, but still better experts should do carefully these changes. I might give a slightly uninformed interepretation of the role of this work in comparison to the experts like Mike.

    • I don’t think we had this page before, at least I couldn’t find it anywhere.

      v1, current

    • Page created, but author did not leave any comments.

      Anonymous

      v1, current

    • started a minimum at M-wave

      (I was after the kind of statement as cited by Chu-Isono there, but have added now a minimum of the background literature, too).

    • Recording the results of some MO questions

      v1, current

    • Page created, but author did not leave any comments.

      v1, current

    • Page created to give link to the series Diagrammes of category theory preprints.

      v1, current

    • Page created, but author did not leave any comments.

      v1, current

    • some minimum, to make links work

      v1, current

    • Page created, but author did not leave any comments.

      Angel Toledo

      v1, current

    • Page created, but author did not leave any comments.

      v1, current

    • some minimum, just for completeness

      v1, current

    • some minimum, on occasion of today’s

      • Giancarlo D’Ambrosio, A. M. Iyer, F. Piccinini, A.D. Polosa, Confronting BB anomalies with atomic physics (arXiv:1902.00893)

      v1, current

    • Created rough paths page. Need to add much more, and add some more pages about probability.

      Anonymous

      v1, current

    • I decided that nLab is probably a better place to develop my ideas than ‘wikipedia’, where I posted one article on this topic but never felt confident to add more, since wikipedia is not really meant for ’ongoing research’. I really liked the idea of using this space for ’public notes on my research’ and am looking forward to getting reactions from some of you.

      As a starter, I feel that using the first-person form in my reporting is more ’honest’ regarding the academic status of the piece. Prefix orders are not an accepted notion in literature yet, I think. The notion itself is used often, but always in a specific context and was (as far as I know) never generalized - until now…

      Pieter Cuijpers

      v1, current

    • Page created, but author did not leave any comments.

      v1, current

    • When writing my page on prefix orders, I found the need to refer to the page on trees. As it turns out, the order theoretic definition that I know for trees was not on it yet, so I decided to add it.

      Pieter Cuijpers

      diff, v24, current

    • Page created, but author did not leave any comments.

      v1, current

    • cross-linked with all nnLab pages that cite Lyubashenko

      diff, v3, current

    • Added a description of slant products in cohomology. Added references to Dold’s book.

      diff, v5, current

    • Update diagrams to tikzcd syntax. Also removed comment about using “Leibniz order” for composition of morphisms, which IMHO was unnecessary and confusing.

      diff, v9, current

    • A stub here. Is there a ready example?

      v1, current

    • suddenly I found a bunch of further references on this, so I am giving this its own entry now, for ease of recording stuff

      v1, current

    • am giving this elementary-but-important fact its own entry, for ease of referencing

      v1, current

    • Created page to record some definitions. I am unable to see the relationship between Bousfield’s definition and Joyal’s, although I included some partial results.

      v1, current

    • created a page for Peter Symonds (Manchester)

      v1, current

    • I want to make a list with (historical) null results in experimental physics that have been important for development of theoretical physics. Puny start so far, hope to collect more

      v1, current

    • slightly expanded the text, realizing more cross-links to existing entries (such as black body radiation). But this and related entries still remain stubs.

      diff, v3, current

    • stub. For the moment just so as to make links work

      v1, current

    • stub, just to make links work, for the moment

      v1, current

    • stub entry, for the moment just so as to satisfy links

      v1, current

    • just to make pointers work, for the moment

      v1, current

    • some minimum, just to make links work

      v1, current

    • started some minimum, to satisfy links

      same comment applies as I just made at chemical element:

      added pointer to

      For a while I thought that this proposal is completely crazy. But in view of the established success of Skyrmion models for atomic nuclei and in particular with these viewed within the Sakai-Sugimoto model, it doesn’t seem completely crazy anymore. I still think it must be admitted that the concrete evidence that there is an actual model of nuclie by complex surfaces is extremely weak and very vague, but I can see now why it is interesting and maybe even tantalizing.

      v1, current

    • changed page name to singluar

      added mentioning of atomic number

      added pointer to

      For a while I thought that this proposal is completely crazy. But in view of the established success of Skyrmion models for atomic nuclei and in particular with these viewed within the Sakai-Sugimoto model, it doesn’t seem completely crazy anymore. I still think it must be admitted that the concrete evidence that there is an actual model of nuclie by complex surfaces is extremely weak and very vague, but I can see now why it is interesting and maybe even tantalizing.

      diff, v2, current

    • Page created, but author did not leave any comments.

      v1, current