Tootfinder

Ammonites made it through the K-Pg extinction event according to this paper! #FossilFriday 🤯
https://www.nature.com/articles/s41598-025-34479-1

Ammonite survival across the Cretaceous–Paleogene boundary confirmed by new data from Denmark - Scientific Reports
We provide a reassessment of the hypothesis of ammonite survival across the Cretaceous–Paleogene (Maastrichtian–Danian) boundary, based on new data from the lower Danian Cerithium Limestone Member at Stevns Klint, eastern Denmark. The occurrence of this unit in disjunct basins between eroded crests of uppermost Maastrichtian bryozoan mounds prompts a reconsideration of ammonite redeposition as an alternative to the survival hypothesis. We describe new ammonite specimens from the Cerithium L…

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Initial experiments on a GPU-accelerated parallel CDR PLL filter.
Fundamentally, the problem is that a PLL is stateful so you can't process any given iteration of it without knowing the previous state. I'm trying to work around that by recognizing that the impulse response of the PLL loop filter tails off to effectively zero after a while, so we can truncate and samples older than that point will not materially affect the output.
What you see here is the first pass of wha…

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Beyond The Boundary West Coast Cricket Club
Where the West Coast Cricket Club boys talk cricket, club life, questionable decisions, and everything in between...
Great Australian Pods Podcast Directory: https://www.greataustralianpods.com/beyond-the-boundary/

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Multispacecraft Measurements of the Evolving Geometry of the Solar #Alfvén Surface over Half a Solar Cycle: https://iopscience.iop.org/article/10.3847/2041-8213/ae0e5c -> Astronomers Create First Map of the Sun's Outer Boundary: https://www.cfa.harvard.edu/news/astronomers-create-first-map-suns-outer-boundary

Infinite-dimensional Lagrange-Dirac systems with boundary energy flow II: Field theories with bundle-valued forms
Fran\c{c}ois Gay-Balmaz, \'Alvaro Rodr\'iguez Abella, Hiroaki Yoshimura
https://arxiv.org/abs/2511.05687 https://arxiv.org/pdf/2511.05687 https://arxiv.org/html/2511.05687
arXiv:2511.05687v1 Announce Type: new
Abstract: Part I of this paper introduced the infinite dimensional Lagrange--Dirac theory for physical systems on the space of differential forms over a smooth manifold with boundary. This approach is particularly well-suited for systems involving energy exchange through the boundary, as it is built upon a restricted dual space -a vector subspace of the topological dual of the configuration space- that captures information about both the interior dynamics and boundary interactions. Consequently, the resulting dynamical equations naturally incorporate boundary energy flow. In this second part, the theory is extended to encompass vector-bundle-valued differential forms and non-Abelian gauge theories. To account for two commonly used forms of energy flux and boundary power densities, we introduce two distinct but equivalent formulations of the restricted dual. The results are derived from both geometric and variational viewpoints and are illustrated through applications to matter and gauge field theories. The interaction between gauge and matter fields is also addressed, along with the associated boundary conditions, applied to the case of the Yang-Mills-Higgs equations.
toXiv_bot_toot

Manipulation of photonic topological edge and corner states via trivial claddings
Hai-Xiao Wang, Li Liang, Shuai Shao, Shiwei Tang, Junhui Hu, Yin Poo, Jian-Hua Jiang
https://arxiv.org/abs/2511.18705 https://arxiv.org/pdf/2511.18705 https://arxiv.org/html/2511.18705
arXiv:2511.18705v1 Announce Type: new
Abstract: Crystalline symmetry offers a powerful tool to realize photonic topological phases, in which additional trivial claddings are typically required to confine topological boundary states. However, the utility of the trivial cladding in manipulating topological waves is often overlooked. Here, we demonstrate two topologically distinct kagome photonic crystals (KPCs) based on different crystalline symmetries: \mathbit{C}_\mathbf{6}- symmetric KPCs exhibit a quantum spin Hall phase, while \mathbit{C}_\mathbf{3}-symmetric KPCs serve as trivial cladding. By tuning the geometric parameter of the trivial cladding, we observe that a pair of topological interface states featured with pseudospin-momentum locking undergoes a phase transition, accompanied by the appearance and disappearance of corner states in a finite hexagonal supercell. Such a geometry-induced band inversion is characterized by a sign change in the Dirac mass of the topological interface states and holds potential for applications such as rainbow trapping. Furthermore, we experimentally demonstrate the corner states, which is a hallmark of higher-order topology, also depend critically on the trivial cladding. Our work highlights the crucial role of trivial claddings on the formation of topological boundary states, and offers a novel approach for their manipulation.
toXiv_bot_toot

Gripped by a terrible #drought now entering its 💥sixth year,
#Iran’s cities are on the brink of what its meteorological organisation calls
♦️“water day zero”:
the boundary beyond which supply systems no longer function.
🔥This was crossed by

A half-space Liouville theorem for anisotropic minimal graph with free boundary
Guofang Wang, Wei Wei, Chao Xia, Xuwen Zhang
https://arxiv.org/abs/2601.15788 https://

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Gloom & Bloom V ☁️🌺
黑暗绽放 V ☁️ 🌺
📷 Nikon F4E
🎞️ Ilford HP5 400 Plus, expired 1993
#filmphotography #Photography #blackandwhite

The Age-Structured Chemostat with Substrate Dynamics as a Control System
Iasson Karafyllis, Dionysis Theodosis, Miroslav Krstic
https://arxiv.org/abs/2511.09963 https://arxiv.org/pdf/2511.09963 https://arxiv.org/html/2511.09963
arXiv:2511.09963v1 Announce Type: new
Abstract: In this work we study an age-structured chemostat model with a renewal boundary condition and a coupled substrate equation. The model is nonlinear and consists of a hyperbolic partial differential equation and an ordinary differential equation with nonlinear, nonlocal terms appearing both in the ordinary differential equation and the boundary condition. Both differential equations contain a non-negative control input, while the states of the model are required to be positive. Under an appropriate weak solution framework, we determine the state space and the input space for this model. We prove global existence and uniqueness of solutions for all admissible initial conditions and all allowable control inputs. To this purpose we employ a combination of Banach's fixed-point theorem with implicit solution formulas and useful solution estimates. Finally, we show that the age-structured chemostat model gives a well-defined control system on a metric space.
toXiv_bot_toot

Some positive signs for AI coding tools. Claude-code is a $1B run rate product six month after launch. The latest Claude Opus 4.5 model is several times cheaper and faster than last month’s version and uses about a quarter of the number of tokens to get work done. My own benchmark saw over an hour of coding reduced to 17 minutes. The high rate of change continues. The boundary of what does/doesn’t work is pushing back fast.

Anthropic acquires Bun as Claude Code reaches $1B milestone
Anthropic is an AI safety and research company that's working to build reliable, interpretable, and steerable AI systems.

Series B, Episode 05 - Pressure Point
ARLE: No hurry.
BERG: Let's get back and report.
ARLE: We've got nothing to report. If we could get back and tell Kasabi what's INSIDE the zone-
BERG: She said as far as the security boundary.
https://blake.torpidity.net/m/205/4

In the second of two episodes to mark the centenary of quantum physics,
we hear how the boundary between the quantum and classical worlds causes huge inconsistencies
—and a debate about the nature of reality itself.
Our guest today,
Vlatko Vedr,
explains his radical vision for fixing those problems and building a consistent understanding of the universe

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Replaced article(s) found for math.DG. https://arxiv.org/list/math.DG/new
[1/1]:
- Topological control for min-max free boundary minimal surfaces
Giada Franz, Mario B. Schulz

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Homotopy rigidity of nearby Lagrangian cocores
Johan Asplund, Yash Deshmukh, Alex Pieloch
https://arxiv.org/abs/2511.09548 https://arxiv.org/pdf/2511.09548 https://arxiv.org/html/2511.09548
arXiv:2511.09548v1 Announce Type: new
Abstract: An exact Lagrangian submanifold $L \subset X^{2n}$ in a Weinstein sector is called a nearby Lagrangian cocore if it avoids all Lagrangian cocores and is equal to a shifted Lagrangian cocore at infinity. Let $k$ be the dimension of the core of the subcritical part of $X$. For $n \geq 2k 2$ we prove that that the inclusion of $L$ followed by the retract to the Lagrangian core of $X$ and the quotient by the $(n-k-1)$-skeleton of the core, is null-homotopic. As a consequence, in many examples, a nearby Lagrangian cocore is smoothly isotopic (rel boundary) to a Lagrangian cocore in the complement of the missed Lagrangian cocores. The proof uses the spectral wrapped Donaldson-Fukaya category with coefficients in the ring spectrum representing the bordism group of higher connective covers of the orthogonal group.
toXiv_bot_toot

huh. TIL: there is a “four corners” place in Canada, like there is more famously in the USA, where Utah, Colorado, Arizona and New Mexico meet.
But ours is automatically cooler, figuratively and literally*, because it is a: at 60° Latitude, and b: involves two Territories and two Provinces.
It is where the Northwest Territories, Nunavut, Saskatchewan, and Manitoba meet.
It is also a LOT harder to get to. Though arguably, as it is amongst the thousands of lakes in the area, during the summer, a float plane would get you there.
Also, technically. It is not a perfect “joining” on the map which is just bad planning on Canada’s part, but at least it is hiking distance. Or that might be just a projection issue. They seem to converge at 60N 102W. I guess I could consult an official boundary document or something :)
Apple Map location: #agw not withstanding
#geography #uselessKnowledge #nerd #maps #canada #sk #mb #nwt #yt #climatechange

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Replaced article(s) found for math.SG. https://arxiv.org/list/math.SG/new
[1/1]:
- Reduction of Cosymplectic groupoids by cosymplectic moment maps
Daniel L\'opez Garcia, Nicolas Martinez Alba
https://arxiv.org/abs/2403.03178 https://mastoxiv.page/@arXiv_mathSG_bot/112047445404247851
- Algebraic Lagrangian cobordisms, flux and the Lagrangian Ceresa cycle
Alexia Corradini
https://arxiv.org/abs/2501.12850 https://mastoxiv.page/@arXiv_mathSG_bot/113876409190220093
- Systolic $S^1$-index and characterization of non-smooth Zoll convex bodies
Stefan Matijevi\'c
https://arxiv.org/abs/2501.13856 https://mastoxiv.page/@arXiv_mathSG_bot/113882071591631203
- Infinite-dimensional Lagrange-Dirac systems with boundary energy flow I: Foundations
Fran\c{c}ois Gay-Balmaz, \'Alvaro Rodr\'iguez Abella, Hiroaki Yoshimura
https://arxiv.org/abs/2501.17551 https://mastoxiv.page/@arXiv_mathSG_bot/113916045279374601
- The Simplicity of the Group of Weakly Hamiltonian Diffeomorphisms on Cosymplectic Manifolds
S. Tchuiaga, P. Bikorimana
https://arxiv.org/abs/2503.10224 https://mastoxiv.page/@arXiv_mathSG_bot/114159599811622365
- Regular semisimple Hessenberg varieties with cohomology rings generated in degree two
Mikiya Masuda, Takashi Sato
https://arxiv.org/abs/2301.03762 https://mastoxiv.page/@arXiv_mathAG_bot/109669428824274443
- Billiards and Hofer's Geometry
Mark Berezovik, Konstantin Kliakhandler, Yaron Ostrover, Leonid Polterovich
https://arxiv.org/abs/2507.04767 https://mastoxiv.page/@arXiv_mathDS_bot/114817105311885626
- Geometric, topological and dynamical properties of conformally symplectic systems, normally hyper...
Marian Gidea, Rafael de la Llave, Tere M-Seara
https://arxiv.org/abs/2508.14794 https://mastoxiv.page/@arXiv_mathDS_bot/115065890424433224
toXiv_bot_toot

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undefined
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