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Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.
brief note comparison theorem (étale cohomology)
brief entry complex analytic topology, just for completeness
we had an entry spectrum (geometry) which wasn’t linked to from almost anywhere, in particular not from spectrum - disambiguation.
I have now added a bunch of cross-links, between these two entries and between the entries that they link to. It’s better now than it was before, but could still do with further improvement.
the entry profinite space and entries related to it were/are a bit in need of some care.
The entry used to start out saying “Profinite space is another word for Stone space”, which was misleading, because there is a not-entirely-trivial equivalence involved. So I changed it to
A profinite set is a pro-object in FinSet. By Stone duality these are equivalent to Stone spaces and thus are often called profinite spaces. So these are compact Hausdorff totally disconnected topological spaces.
Also cross-links with profinite reflection were missing, and so I added them. Also cross-linked with finite set, with localic reflection and maybe with more.
The entry profinite space is still stubby/unsatisfactory.
started entries
Question: We have the implications
étale morphism weakly étale morphism formally étale morphism
but can one say more specifically what kind of generalized finite presentability condition makes a formally étale morphism a weakly étale morphism?
I have fixed some dead links relating to Loday which were occurring n several pages.
made a note of a simple observation:
for an atom in a cohesive -topos over , then also the slice is cohesive … except possibly for the property that shape preserves binary products (but it does preserve the terminal object):
stub for chromatic spectral sequence, so far mainly to record that it arises as the Lurie spectral sequence of the chromatic tower (thanks to Dylan Wilson and Marc Hoyois)
Created continuous algebra.
now the preprint referred to at tangent cohesive (infinity,1)-topos is out:
I noted an entry on generalized Eilenberg-MacLane spaces, but note that there is another use of this term in the literature, namely the representing fibrations for cohomology with local coefficients. These are the fibrations used by Gitler and then by Alan Robinson, Hans Baues and others more recently. What would be the preferred name for these latter things. (I personally find the idea of giving a name to products of Eilenberg- Mac Lane spaces other that ‘products of Eilenberg - Mac Lane spaces’ a bit strange, but I know that there is some strange terminology around!)
I noticed by accident that we have an entry coinvariant. Then I noticed that we also have an entry homotopy coinvariant functor.
I have now added cross-links between these entries and with invariant and orbit, so that they no longer remain hidden.
I also edited the first case of group representation coinvariants at coinvariant a little.
this Physics.SE question made me create a category:reference entry for
I noticed that some old entries were requesting a keyword link for brave new algebra, so I created it and filled in a default-paragraph. Please feel invited to expand.
In that context I have a question: the dual generlized Steenrod algebras have been called “brave new Hopf algebroids” in articles including
Andrew Baker, Brave new Hopf algebroids (pdf)
Andrew Baker and Alain Jeanneret, Brave new Hopf algebroids and extensions of -algebras, Homology Homotopy Appl. Volume 4, Number 1 (2002), 163-173. (Euclid)
Mark Hovey, Homotopy theory of comodules over a Hopf algebroid (arXiv:math/0301229)
But the Hopf algebroids considered in these articles are ordinary Hopf algebroids, they are given not by Hopf -algebras but by their homotopy groups , unless I am missing something.
So at least without further discussion, calling “brave new” is a bit of a stretch. The brave new thing would be (if indeed it is a “Hopf -algebroid”).
Can anyone say more about this? I can’t seem to find any source talking about this. The canonical guess of googling for “derived Hopf algebroid” doesn’t show relevant results.
created Landweber-Novikov theorem
started motives in physics with text that I posted as an answer to this Physics.SE question.
Needs to be polished and expanded. But I have to run now.
since it appears in several entries and probably more to come, I gave it an entry of its own: Quillen’s theorem on MU
also gave an entry to Lazard’s theorem
I needed finite spectrum
To be able to conveniently link I have also splitt of finite CW-complex from CW-complex
some basics at Lubin-Tate theory
(wanted to do more, but the nLab is giving me a really hard (down-)time )
created a table-for-inclusion image of J – table listing pertinent information in low degree, and included it in some relevant entries
started a very stubby
along with very stubby
and a very stubby
Had wanted to do more, but now I am running out of steam. Maybe the stubs inspire somebody to add a little more…
created a brief entry for Bousfield equivalence
I messed up slightly: i had forgotten that there was already a stub titled contact geometry. Now I have created contact manifold with some content that might better be at contact geometry. I should fix this. But not right now.
created Einstein’s equation, only to record a writeup by Gonzalo Reyes which I just came across by chance, who gives a discussion in terms of synthetic differential geometry.
quick entry for phantom map
brief Idea-section at chromatic convergence theorem
stub for telescopic localization,
finally created the category:reference-entry for Lurie’s chromatic lecture. See Chromatic Homotopy Theory
(And as a special service to the community… with lecture titles. ;-)
Lecture 1 Introduction (pdf)
Lecture 2 Lazard’s theorem (pdf)
Lecture 3 Lazard’s theorem (continued) (pdf)
Lecture 4 Complex-oriented cohomology theories (pdf)
Lecture 5 Complex bordism (pdf)
Lecture 6 MU and complex orientations (pdf)
Lecture 7 The homology of MU (pdf)
Lecture 8 The Adams spectral sequence (pdf)
Lecture 9 The Adams spectral sequence for MU (pdf)
Lecture 10 The proof of Quillen’s theorem (pdf)
Lecture 11 Formal groups (pdf)
Lecture 12 Heights and formal groups (pdf)
Lecture 13 The stratification of (pdf)
Lecture 14 Classification of formal groups (pdf)
Lecture 15 Flat modules over (pdf)
Lecture 16 The Landweber exact functor theorem (pdf)
Lecture 17 Phanton maps (pdf)
Lecture 18 Even periodic cohomology theories (pdf)
Lecture 19 Morava stabilizer groups (pdf)
Lecture 20 Bousfield localization (pdf)
Lecture 21 Lubin-Tate theory (pdf)
Lecture 22 Morava E-theory and Morava K-theory (pdf)
Lecture 23 The Bousfield Classes of and (pdf)
Lecture 24 Uniqueness of Morava K-theory (pdf)
Lecture 25 The Nilpotence lemma (pdf)
Lecture 26 Thick subcategories (pdf)
Lecture 27 The periodicity theorem (pdf)
Lecture 28 Telescopic localization (pdf)
Lecture 29 Telescopic vs -localization (pdf)
Lecture 30 Localizations and the Adams-Novikov spectral sequence (pdf)
Lecture 31 The smash product theorem (pdf)
Lecture 32 The chromatic convergence theorem (pdf)
Lecture 33 Complex bordism and -localization (pdf)
Lecture 34 Monochromatic layers (pdf)
Lecture 35 The image of (pdf)
created a stub for cluster decomposition, since I wanted the link elsewhere, but nothing there yet…
I recently created entry Bol loop. Now I made some corrections and treated the notion of a core of a right Bol loop (the term coming allegedly from Russian term сердцевина).
created a disambiguation page: spectral geometry
New article: Tychonoff space.
I gave the book
a category:reference entry and linked to it from a few relevant entries.
started stubs E-∞ geometry, E-∞ scheme.
To be filled with more content, for the moment I just need to be able to use the links.
I am starting entries
for the moment mostly to collect some references. But not much there yet. But if anyone can provide furher hints, that would be welcome.
have split-off quantization of loop groups from loop group
created A Survey of Elliptic Cohomology - elliptic curves with seminar notes on an exposition on elliptic curves.
Am hoping that some kind soul will eventually further go through these seminar notes and copy bits of material to separete entries, where it belongs. Eventually.
have created affine modality
I have created a stub for n-truncation modality and cross-linked with double negation modality.
I gather that double negation = (-1)-truncation in a “predicative context”, but maybe I don’t fully understand yet what predicativity has to do with it.
I have added some more informative Idea-sentences to Adams spectral sequence and to Adams-Novikov spectral sequence. Also added more references.
felt like the nLab should have an entry fraction
have split off an entry stable unitary group from the material at topological K-theory
added the “song of stable homotopy groups” to stable orthogonal group
Popped my head round the door and made a couple of changes to Banach algebra
The first change was to attempt a more lax position on what should constitute a Banach coalgebra: only looking at comonoids in the monoidal category of Banach spaces (geometric or topogical) with projective tensor product would rule out several important examples that have arisen in e.g. abstract harmonic analysis. The existence of different monoidal structures in the category of Banach spaces is a pain, but without it one would miss out on a rich world of examples.
The second was to add, to the list of examples, the celebrated-in-my-world-and-possibly-no-others Arens products on the double dual of a Banach algebra. I’ve made a stab at linking them to the related concepts of tensorial strength and strong monad but would welcome feedback or improvements.
New entry synthetic projective geometry and also sort of disambiguation and history page synthetic geometry making a distinction with synthetic differential geometry.
Stephen Gaito has joined with a question at cardinal number. I tried to reply.
isotope (physics) and isotope (algebra) with redirect for isotopy (algebra). I have read and thought much about isotopies in last couple of weeks, but no time at this point to write much about it into Lab.
Added references to the recent Riehl-Verity papers to quasi-category, adjoint (infinity,1)-functor and monadicity theorem. Any more places it should go?
started Weil conjecture
Chris Schommer-Pries posted a question/suggestion in the query box at semisimple category
have added to the Idea-section at Schubert calculus the following paragraph:
Schubert calculus is concerned with the ring structure on the cohomology of flag varieties and Schubert varieties. Traditionally this was considered for ordinary cohomology (see References – traditional) later also for generalized cohomology theories (see References – In generalized cohomology), notably in complex oriented cohomology theory such as K-theory, elliptic cohomology and algebraic cobordism.
And have added references on Schubert calculus for generalized cohomology.
I gave the following an category:reference-entry
and linked to it from various relevant entries.
stub for reductive group
… need not be , but it shouldn't be larger; remarks about this are now at Banach algebra (and also at JB-algebra).
stub for Kac character formula, for the moment just so as to record the citations.
We don't actually need essentially bounded functions as such, since measurable functions should only be almost-everywhere defined by default, but there they are.
There is a deliberately ambiguous stub at finite-dimensional space.
We might collect there all of the nice things about finite-dimensional spaces (for various notions of ’space’).