User talk:TakuyaMurata

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Coherence theorem for bicategory and 2-Yoneda lemma

I added the Coherence theorem to the 2-category, but perhaps it would be better to move it to the application section of the 2-Yoneda lemma? Also, does 2-Yoneda lemma refer to the Yoneda lemma for bicategory or the Yoneda lemma for strict 2-category? SilverMatsu (talk) 03:24, 27 April 2025 (UTC)[reply]

First, I think the coherence theorem makes much more sense in the 2-category article since it's about comparing weak and strict versions. Second, if I am not mistaken, I think the 2-Yoneda should work both for strict and weak 2-categories but the article should probably clarify that (this is why the proof is sketch.) -- Taku (talk) 07:22, 27 April 2025 (UTC)[reply]

I see. Thank you for explaining it to me.--SilverMatsu (talk) 09:16, 27 April 2025 (UTC)[reply]

Just let you know, wikipedia has Tricategory and 3-category is a redirect to Strict higher categories. In other words, weak 3-category and strict 3-categories seem to be separate articles.SilverMatsu (talk) 10:19, 27 April 2025 (UTC)[reply]

Maybe we don’t need separate articles 3-categories (strict or weak), since they seem to be less prominent than 2-categories. I would suggest the merger (to higher category theory for instance) —- Taku (talk) 06:51, 28 April 2025 (UTC)[reply]

I agree to merge. I think Tetracategory can be merged as well. But, a better target for redirection might be Weak n-category. Of course, it is possible to merge the weak n-category into the higher category theory.SilverMatsu (talk) 15:14, 28 April 2025 (UTC)[reply]

I’m not too sure if everything should be merged into “higher category theory”. It seems an n-category (weak or strict) deserves its own article. Certainly, higher category theory isn’t just about the study of n-categories. —- Taku (talk) 16:19, 28 April 2025 (UTC)[reply]

The coherence theorem for tricategory states that tricategory is triequivalent to Gray-category. So the strict version of tricategory seems to be Gray-category. Also, the coherence theorem does not seem to have been found for n>3. See https://mathoverflow.net/questions/334849/coherence-theorem-for-tetracategories-weak-n-categories and Lack, Stephen (2011). "A Quillen model structure for Gray-categories". Journal of K-Theory. 8 (2): 183–221. arXiv:1001.2366. doi:10.1017/is010008014jkt127.SilverMatsu (talk) 06:18, 29 April 2025 (UTC)[reply]

Thank you. So on second thought, maybe it makes sense to have an article on 3-category just as we have one on 2-category. I have already begun the draft Draft:3-category, where we can discuss Gray tensor product and such too. Taku (talk) 07:06, 29 April 2025 (UTC)[reply]

Speedy deletion nomination of Walks on ordinals

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A tag has been placed on Walks on ordinals requesting that it be speedily deleted from Wikipedia. This has been done under section G4 of the criteria for speedy deletion, because the page appears to be a repost of material that was previously deleted following a deletion discussion, at [[Special:PermanentLink/1268286608#Walks on ordinals]]. When a page has substantially identical content to that of a page deleted after a discussion, and any changes in the content do not address the reasons for which the material was previously deleted, it may be deleted at any time.

If you think this page should not be deleted for this reason, you may contest the nomination by visiting the page and clicking the button labelled "Contest this speedy deletion". This will give you the opportunity to explain why you believe the page should not be deleted. However, be aware that once a page is tagged for speedy deletion, it may be deleted without delay. Please do not remove the speedy deletion tag from the page yourself, but do not hesitate to add information in line with Wikipedia's policies and guidelines. If the page is deleted, and you wish to retrieve the deleted material for future reference or improvement, then please contact the deleting administrator, or if you have already done so, you can place a request here. Valorrr ^{(lets chat)} 04:31, 27 April 2025 (UTC)[reply]

The Japanese Red Cross Kyushu International College of Nursing moved to draftspace

Thanks for your contributions to The Japanese Red Cross Kyushu International College of Nursing. Unfortunately, I do not think it is ready for publishing at this time because of the discussion outcome at Wikipedia:Articles for deletion/The Japanese Red Cross Kyushu International College of Nursing. I have converted your article to a draft which you can improve, undisturbed for a while.

Please see more information at Help:Unreviewed new page. When the article is ready for publication, please click on the "Submit your draft for review!" button at the top of the page OR move the page back. Dclemens1971 (talk) 01:58, 28 April 2025 (UTC)[reply]

Higher category theory

Hello! First, thanks a lot for all your contributions to higher category theory! I already translated some of your articles into German in the past. I'm writing you because I just created seven new articles about higher category theory and noticed, after creating the one for the twisted diagonal, that you've already dead-linked it in one of your contributions. Since we're both active in the same area and both use Denis-Charles Cisinski's Homotopical Algebra as a source, I want to avoid any collisions. Therefore: I'm basically done with contributing to higher category theory in the English Wikipedia anyway and will soon go back to differential geometry or other different areas and also translating articles for the German Wikipedia, since both of us have written a lot to catch up to. The only articles I still plan to create are one for the Grothendieck–Segal condition and Homotopical Algebra itself, maybe also for proper/smooth and final/cofinal morphisms, but I still have to think about that. You can of course tell me, if you plan to do that as well. I don't plan to create the article Hom functor of an ∞-category, which I've dead-linked on twisted diagonal, since it fits more what you're writing and you're surely more qualified to do so.

Also, what do you think about an own article about anodyne extensions? I've thought about writing one for the German Wikipedia and then found out you've extended the notes in the English Wikipedia. Samuel Adrian Antz (talk) 06:47, 2 May 2025 (UTC)[reply]

Hi. I have definitely been noticing that you have added quite a few materials on higher category theory too (and I'm very flattered for being thanked). I am not really worried much about the collisions. After all, in Wikipedia, articles are supposed to be co-written by various editors (not much different from co-authored papers). Currently I don't have much a plan to add stuff from Cisinski's book. I'm more interested in stacks. As for the hom functor, a natural place for it is probably quasi-category. I'm not sure if we need a separate article for it. In Higher Topos Theory, Lurie actually gives a very simple quick construction using topology before stating the infinity-version of Yoneda's lemma. So, maybe that's the best approach (it seems Cisinski likes to avoid topology). For anodyne extensions, as you probably know, the notion also exists more generally than just for simplicial sets. So, maybe a standalone article on it may make sense. (I will probably not create one myself, though.) Another possibility is to put the topic in a standalone article on construction of model category structures or something. -- Taku (talk) 10:43, 2 May 2025 (UTC)[reply]

Merge proposal

Regarding the proposal to merge Coherence condition and Coherency (homotopy theory), where I removed the templates (and you reversed), it wasn't that the proposal had been open for too long, but rather that there was no case made, and the case isn't obvious. See WP:MERGEPROP Step 1. Would you mind making a case for the merge? Klbrain (talk) 14:43, 2 May 2025 (UTC)[reply]

I guess it depends on editors whether the rationale for the merger is clear or not. For me, it was very obvious as the two articles are about the same topic (though the scopes are somehow different). If asked, I can certainly elaborate on the merger rationale (and will do in a second). -- Taku (talk) 16:22, 2 May 2025 (UTC)[reply]

In the first place, (definition of) the n-categorie (theory) are algebraic structures that incorporate concepts from homotopy theory, and the coherent condition is a phrase that appears in the definition. I wish there was an wikipedia article somewhere that explained the relationship between (higher) category theory and homotopy theory... (look as if: https://mathoverflow.net/questions/61781/what-is-the-homotopy-theory-of-categories, Baez, John C.; Dolan, James (1998). "Categorification". arXiv:math/9802029.) --SilverMatsu (talk) 03:33, 5 May 2025 (UTC)[reply]

But that's basically exactly homotopy hypothesis, isn't it, as it says coherent laws in algebra are the same thing or amounts to homotopy theory. So, my merger proposal is actually based on that hypothesis: coherent laws should be discussed in the context of homotopy theory. Although it's still a conjecture in some ways, I don't think anyone doubts homotopy hypothesis (thus can be taken as a truth). -- Taku (talk) 04:26, 6 May 2025 (UTC)[reply]

Thank you for your reply. It certainly seems like a coherent law rather than a coherent condition. By the way, when I was reading the reference for homotopy hypothesis, I found the Joyal theorem. So I made a draft, but maybe I should make the title clearer. Also is there any other theorem called the Joyal theorem?SilverMatsu (talk) 08:13, 11 May 2025 (UTC)[reply]

I don't think there is much difference between coherent laws and coherent conditions. It's similar to the case that associativity can both be described as a law or a condition; even an isomorphism in higher algebra. As for Joyal's theorem, yes, I think a separate article makes sense, as we don't want a proof of the theorem in the homotopy hypothesis article. The theorem doesn't seem to have any specific name so for now, "Joyal's theorem" is probably fine as a name. Taku (talk) 13:31, 12 May 2025 (UTC)[reply]

"Higer K-group" listed at Redirects for discussion

The redirect Higer K-group has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Anyone, including you, is welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2025 May 4 § Higer K-group until a consensus is reached. 1234qwer1234qwer4 03:02, 4 May 2025 (UTC)[reply]

Derived ring theory

Hi @TakuyaMurata: I'm reviewing this article. Why did you remove from draft when its an absolute mess? scope_creep^Talk 06:19, 6 May 2025 (UTC)[reply]

I didn't think it's a mess. At least the lead looks ok. While the article needs more development, the development can happen in mainspace too. -- Taku (talk) 06:21, 6 May 2025 (UTC)[reply]

Its a complete mess. I can't even tag because it would take about 9 tags because its so trash. I can't even look at it. The next time you do that, I'm going going to report you to admin for disruptive editing and WP:CIR issues and I'm going to try and get you blocked. scope_creep^Talk 08:18, 6 May 2025 (UTC)[reply]

Sorry, what are issues exactly? For example, it lists several refs. Yes, there is an incomplete section but that’s completely acceptable, as Wikipedia articles can be incomplete in some respects. —- Taku (talk) 08:43, 6 May 2025 (UTC)[reply]

Also, threatening other fellow editions would actually get you blocked. So, you probably don’t want to do that. —- Taku (talk) 08:45, 6 May 2025 (UTC)[reply]

Derived ring theory moved to draftspace

Thanks for your contributions to Derived ring theory. Unfortunately, I do not think it is ready for publishing at this time because needs significant work before it is acceptable as an encyclopedia entry. I have converted your article to a draft which you can improve, undisturbed for a while.

Please see more information at Help:Unreviewed new page. When the article is ready for publication, please click on the "Submit the draft for review!" button at the top of the page OR move the page back. UtherSRG (talk) 11:59, 6 May 2025 (UTC)[reply]

So, I don’t know what you mean by significant work. For example, the lead looks fairly complete and the article also already lists several refs. So, the article looks fine as a stub. I have therefore undone the draftifying. —- Taku (talk) 12:13, 6 May 2025 (UTC)[reply]

Deletion discussion about Derived ring theory

Hello TakuyaMurata, and thank you for your contributions to Wikipedia.

While your contributions are appreciated, I wanted to let you know that I've started a discussion about whether an article that you created, Derived ring theory, should be deleted, as I am not sure that it is suitable for inclusion in Wikipedia in its current form. Your comments are welcome at Wikipedia:Articles for deletion/Derived ring theory.

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Afonso Dimas Martins (talk) 17:31, 6 May 2025 (UTC)[reply]

Nori motive moved to draftspace

Thanks for your contributions to Nori motive. Unfortunately, I do not think it is ready for publishing at this time because it has no sources and in-text citations are needed per WP:CITE which will also help to create formatted references per WP:REFSTART. I have converted your article to a draft which you can improve, undisturbed for a while.

Please see more information at Help:Unreviewed new page. When the article is ready for publication, please click on the "Submit the draft for review!" button at the top of the page OR move the page back. FULBERT (talk) 16:43, 9 May 2025 (UTC)[reply]

What do you mean "no sources???" The article actually lists several sources. -- Taku (talk) 05:41, 10 May 2025 (UTC)[reply]

Nomination of Nori motive for deletion

A discussion is taking place as to whether the article Nori motive is suitable for inclusion in Wikipedia according to Wikipedia's policies and guidelines or whether it should be deleted.

The article will be discussed at Wikipedia:Articles for deletion/Nori motive until a consensus is reached, and anyone, including you, is welcome to contribute to the discussion. The nomination will explain the policies and guidelines which are of concern. The discussion focuses on high-quality evidence and our policies and guidelines.

Users may edit the article during the discussion, including to improve the article to address concerns raised in the discussion. However, do not remove the article-for-deletion notice from the top of the article until the discussion has finished.

UtherSRG (talk) 11:59, 10 May 2025 (UTC)[reply]