Hackers' Pub

Syntax	Description	Examples
`"` keyword `"`	Finds the string within quotes, including spaces. Case-insensitive. (Escape quotes inside with `\"`)	`"Hackers' Pub"`
`from:` handle	Finds content written by the specified user.	`from:hongminhee` `from:hongminhee@hollo.social`
`lang:` ISO 639-1	Finds content written in the specified language.	`lang:en`
`#` tag	Finds content with the specified tag. Case-insensitive.	`#HackersPub`
condition condition	Finds content that satisfies both conditions on either side of the space (logical AND).	`"Hackers' Pub" lang:en`
condition `OR` condition	Finds content that satisfies at least one of the conditions on either side of the OR operator (logical OR).	`#HackersPub OR "Hackers' Pub" lang:en`
`(` condition `)`	Combines the operators within the parentheses first.	`(#HackersPub OR "Hackers' Pub" OR "Hackers Pub") lang:en`

Cat 🐈🥗 (D.Burch) ⁠ @catsalad@infosec.exchange

9/25/2025, 7:59:28 PM

Public

@sophieschmieg OwO, what's this?

https://arxiv.org/abs/2506.24088

Unknotting number is not additive under connected sum

We give the first examples of a pair of knots $K_1$,$K_2$ in the 3-sphere for which their unknotting numbers satisfy $u(K_1\#K_2)<u(K_1)+u(K_2)$ . This answers question 1.69(B) from Kirby's problem list, "Problems in low-dimensional topology", in the negative.

arxiv.org · arXiv.org

Sophie Schmieg @sophieschmieg@infosec.exchange

9/25/2025, 8:02:46 PM

Quiet public

@catsaladCat 🐈🥗 (D.Burch) ⁠ what if 👉👈🥺 we studied unknotting numbers together?

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