Tootfinder

Line bundles and exact sequences for the ideal class group and the Picard group
Abolfazl Tarizadeh
https://arxiv.org/abs/2508.19889 https://arxiv.org/pdf/2…

Line bundles and exact sequences for the ideal class group and the Picard group
For any extension of commutative rings $A\subseteq B$ we first naturally define a group $\Cl(A,B)$, that we call the ideal class group of this extension (we will see that both the classical ideal class group and, surprisingly, the Picard group are special cases of this structure), then, as a first main result, we obtain the following exact sequence of Abelian groups: ...

Day 30: Elizabeth Moon
This last spot (somehow 32 days after my last post, but oh well) was a tough decision, but Moon brings us full circle back to fantasy/sci-fi, and also back to books I enjoyed as a teenager. Her politics don't really match up to Le Guin or Jemisin, but her military experience make for books that are much more interesting than standard fantasy fare in terms of their battles & outcomes (something "A Song of Ice and Fire" achieved by cribbing from history but couldn't extrapolate nearly as well). I liked (and still mostly like) her (unironically) strong female protagonists, even if her (especially more recent) forays into "good king" territory leave something to be desired. Still, in Paksenarion the way we get to see the world from a foot-soldier's perspective before transitioning into something more is pretty special and very rare in fantasy (I love the elven ruins scene as Paks travels over the mountains as an inflection point). Battles are won or lost on tactics, shifting politics, and logistics moreso than some epic magical gimmick, which is a wonderful departure from the fantasy norm.
Her work does come with a content warning for rape, although she addresses it with more nuance and respect than any male SF/F author of her generation. Ex-evangelicals might also find her stuff hard to read, as while she's against conservative Christianity, she's very much still a Christian and that makes its way into her writing. Even if her (not bad but not radical enough) politics lead her writing into less-satisfying places at times, part of my respect for her comes from following her on Twitter for a while, where she was a pretty decent human being...
Overall, Paksenarrion is my favorite of her works, although I've enjoyed some of her sci-fi too and read the follow-up series. While it inherits some of Tolkien's baggage, Moon's ability to deeply humanize her hero and depict a believable balance between magic being real but not the answer to all problems is great.
I've reached 30 at this point, and while I've got more authors on my shortlist, I think I'll end things out tomorrow with a dump of also-rans rather than continuing to write up one per day. I may even include a man or two in that group (probably with at least non-{white cishet} perspective). Honestly, doing this challenge I first thought that sexism might have made it difficult, but here at the end I'm realizing that ironically, the misogyny that holds non-man authors to a higher standard means that (given plenty have still made it through) it's hard to think of male authors who compare with this group.
Looking back on the mostly-male authors of SF/F in my teenage years, for example, I'm now struggling to think of a single one whose work I'd recommend to my kids (having cheated and checked one of my old lists, Pratchett, Jaques, and Asimov qualify but they're outnumbered by those I'm now actively ashamed to admit I enjoyed). If I were given a choice between reading only non-men or non-woman authors for the rest of my life (yes I'm giving myself enby authors as a freebie; they're generally great) I'd very easily choose non-men. I think the only place where (to my knowledge) not enough non-men authors have been allowed through to outshine the fields of male mediocrity yet is in videogames sadly. I have a very long list of beloved games and did include some game designers here, but I'm hard-pressed to think of many other non-man game designers I'd include in the genuinely respect column (I'll include at least two tomorrow but might cheat a bit).
TL;DR: this was fun and you should do it too.
#30AuthorsNoMen

"When I hear international leaders speak of “Israel’s right to defend itself,” I wonder: against whom? Against mothers with their babies? Against teachers with their board markers? Against students with their books? The global silence — or worse, complicity — amplifies our grief" -- Dr Hassan El-Nabih

‘I’m happy and sad to see you’: The paradox of surviving the Gaza genocide
A chance encounter with one of my past students at the Islamic University of Gaza highlighted the paradox of surviving the Gaza genocide: feeling joy in surviving the war and sorrow in witnessing what our survival has cost us.

Garnet fire burns into grove of giant sequoias; several behemoths are in flames
https://www.latimes.com/environment/story/2025-09-08/garnet-fire-burns-into-grove-of-giant-sequoias-several-trees-are-in-flames

Garnet fire burns into grove of giant sequoias; several behemoths are in flames
A fire burning in Fresno County has reached the McKinley grove of giant sequoias. Several trees are in flames and specially trained firefighters are on their way to put them out.

H-Net Job Guide Weekly Report for H-Grad: 17 August - 24 August https://networks.h-net.org/group/announcements/20123261/h-net-job-guide-weekly-report-h-grad-17-august-24-august

JWST reveals a supernova following a gamma-ray burst at z $\simeq$ 7.3
A. J. Levan, B. Schneider, E. Le Floc'h, G. Brammer, N. R. Tanvir, D. B. Malesani, A. Martin-Carrillo, A. Rossi, A. Saccardi, A. Sneppen, S. D. Vergani, J. An, J. -L. Atteia, F. E. Bauer, V. Buat, S. Campana, A. Chrimes, B. Cordier, L. Cotter, F. Daigne, V. D'Elia, M. De Pasquale, A. de Ugarte Postigo, G. Corcoran, R. A. J. Eyles-Ferris, H. Fausey, A. S. Fruchter, O. Godet, B. P. Gompertz, D. Gotz, N. Habeeb…

JWST reveals a supernova following a gamma-ray burst at z $\simeq$ 7.3
The majority of energetic long-duration gamma-ray bursts (GRBs) are thought to arise from the collapse of massive stars, making them powerful tracers of star formation across cosmic time. Evidence for this origin comes from the presence of supernovae in the aftermath of the GRB event, whose properties in turn link back to those of the collapsing star. In principle, with GRBs we can study the properties of individual stars in the distant universe. Here, we present JWST/NIRCAM observations that d…

Galois theory by calculator
Thomas W. Mattman, Robertson-Figaniak, Zoe Steele
https://arxiv.org/abs/2508.18595 https://arxiv.org/pdf/2508.18595

Galois theory by calculator
We present an algorithm to determine the Galois group of an irreducible monic polynomial $f(x) \in \mathbb{Z}[x]$ of degree at most five. Following work of Conrad, Dummit, and Stauduhar this comes down to answering two questions: Is a given integer a square? and Does a given polynomial have an integral root? Since these are both easily addressed with a calculator, our algorithm amounts to Galois theory by calculator. For example, we have an implementation at Desmos.com. In an appendix we presen…

“A string of bands have pulled out of a UK music festival hours before they were due to perform after Irish band The Mary Wallopers said they were ‘cut off’ for displaying a Palestinian flag.
The Last Dinner Party, Cliffords and The Academic announced on Saturday that they would no longer be performing at the Victorious festival in Portsmouth following Friday’s incident.
…
Rock band The Last Dinner Party said they would boycott the festival in a statement shared on their Inst…

Bands pull out of UK music festival after The Mary Wallopers say they were ‘cut off’
Irish folk group displayed Palestinian flag on stage in Portsmouth

H-Net Job Guide Weekly Report for H-Buddhism: 17 August - 24 August https://networks.h-net.org/group/announcements/20123243/h-net-job-guide-weekly-report-h-buddhism-17-august-24-august

WORKSHOP> Doctoral School Specialist Course for PhD students at Ghent University (Belgium): “Current Research on Middle Chinese and ‘Buddhist Hybrid Chinese’” #acrel https://