Tootfinder

Vultron, which makes AI tools for federal contractors, raised $22M from investors including David Sacks' Craft Ventures, raising ethical questions (Connie Loizos/TechCrunch)
https://techcrunch.com/2025/07/19/david-sacks-and-the-blurred-lines-of-…

David Sacks and the blurred lines of government service | TechCrunch
When Vultron announced its $22 million funding round earlier this week, the AI startup made sure to highlight a key investor: Craft Ventures, the firm

Integrability of Kepler Billiards at Zero-Energy
Lei Zhao
https://arxiv.org/abs/2507.15879 https://arxiv.org/pdf/2507.15879

Integrability of Kepler Billiards at Zero-Energy
We show that if a Kepler billiard in the plane defined inside a smooth closed connected simple curve intersecting all focused parabola at at most two points is integrable at its zero-energy, then the system is defined actually inside an ellipse with the Kepler center occupying one of the foci. This statement is obtained as a simple ``translation'' of the theorem of Bialy-Mironov 2022 with Levi-Civita transformation.

Quantum chaos and semiclassical behavior in mushroom billiards I: Spectral statistics
Matic Orel, \v{C}rt Lozej, Marko Robnik, Hua Yan
https://arxiv.org/abs/2507.13823

Quantum chaos and semiclassical behavior in mushroom billiards I: Spectral statistics
We study the aspects of quantum chaos in mushroom billiards introduced by Bunimovich. This family of billiards classically has the property of mixed phase space with precisely one entirely regular and one fully chaotic (ergodic) component, whose size depends on the width w of the stem, and has two limiting geometries, namely the circle (as the integrable system) and stadium (as the fully chaotic system). Therefore, this one-parameter system is ideal to study the semiclassical behavior of the qu…

Outer symplectic billiard map at infinity
Peter Albers, Ana Chavez Caliz, Serge Tabachnikov
https://arxiv.org/abs/2508.15142 https://arxiv.org/pdf/2508.151…

Outer symplectic billiard map at infinity
We show that the second iteration $T^2$ of the outer symplectic billiard map with respect to a convex domain $M$ in a symplectic vector space is approximated by an explicit Hamiltonian flow for points far away from $M$. More precisely, denote by $N$ the symplectic polar dual of the symmetrization $M\ominus M$ of $M$. If we write $N$ as the unit level set of a 1-homogeneous function $H$, then the difference between $T^2$ and the time-2-Hamiltonian flow of $H$ applied to a point $x$ is smaller …

Luiz Pessoa: Beyond billard ball causation in the brain!
https://www.thetransmitter.org/the-big-picture/beyond-newtonian-causation-in-neuroscience-embracing-complex-causality/
@…

Beyond Newtonian causation in neuroscience: Embracing complex causality
The traditional mechanistic framework must give way to a richer understanding of how brains actually generate behavior over time.

DNA-DetectLLM: Unveiling AI-Generated Text via a DNA-Inspired Mutation-Repair Paradigm
Xiaowei Zhu, Yubing Ren, Fang Fang, Qingfeng Tan, Shi Wang, Yanan Cao
https://arxiv.org/abs/2509.15550

DNA-DetectLLM: Unveiling AI-Generated Text via a DNA-Inspired Mutation-Repair Paradigm
The rapid advancement of large language models (LLMs) has blurred the line between AI-generated and human-written text. This progress brings societal risks such as misinformation, authorship ambiguity, and intellectual property concerns, highlighting the urgent need for reliable AI-generated text detection methods. However, recent advances in generative language modeling have resulted in significant overlap between the feature distributions of human-written and AI-generated text, blurring class…

So I've started going through photos from 2015/2016 to add location tags to them. Conclusions so far:
1. Damn, these photos have low resolution. I mean, 2560 x 1440? That's smaller than my screen right now!
2. So many of them are really bad, like blurred, or really non-level, or with fingers.
3. I seemed to enjoy panoramas. Very low resolution panoramas, I should add.
4. I hate apps for defaulting not to store location data. Before I noticed it, I made so many photos I can't figure out.
5. That said, I still can recognize a lot of places by seemingly random scenery elements.
6. In many cases, "what? *that* was 10 years ago?!"

Planck constraints on the scale dependence of isotropic cosmic birefringence
M. Ballardini, A. Gruppuso, S. Paradiso, S. S. Sirletti, P. Natoli
https://arxiv.org/abs/2507.16714

Planck constraints on the scale dependence of isotropic cosmic birefringence
The rotation of the linear polarisation plane of photons during propagation, also known as cosmic birefringence, is a powerful probe of parity-violating extensions of standard electromagnetism. Using Planck legacy data, we confirm previous estimates of the isotropic birefringence angle, finding $β\simeq 0.30 \pm 0.05$ [deg] at 68% CL, not including the systematic error from the instrumental polarisation angle. If this is a genuine signal, it could be explained by theories of Chern--Simons-type…

City Features VIII 👣
城市特征 VIII 👣
📷 Nikon FE
🎞️Ilford FP4 Plus, expired 1994
buy me ☕️ ?/请我喝杯☕️？
#filmphotography

Euclid preparation: Expected constraints on initial conditions
Collaboration, Finelli, Akrami, Andrews, Ballardini, Casas, Karagiannis, Sakr, Valiviita, Alestas, Bartolo, Bermejo-Climent, Nesseris, Paoletti, Sapone, Tutusaus, Ach\'ucarro, Ca\~nas-Herrera, Jasche, Lavaux, Aghanim, Altieri, Amara, Amendola, Andreon, Auricchio, Baccigalupi, Bagot, Baldi, Bardelli, Battaglia, Biviano, Branchini, Brescia, Camera, Capobianco, Carbone, Carretero, Castellano, Castignani, Cavuoti, Chambers,…

Euclid preparation: Expected constraints on initial conditions
The Euclid mission of the European Space Agency will deliver galaxy and cosmic shear surveys, which will be used to constrain initial conditions and statistics of primordial fluctuations. We present highlights for the Euclid scientific capability to test initial conditions beyond LCDM with the main probes, i.e. 3D galaxy clustering from the spectroscopic survey, the tomographic approach to 3x2pt statistics from photometric galaxy survey, and their combination. We provide Fisher forecasts from t…