Tootfinder

A look at Amsterdam's failed experiment to create a fair welfare AI system that would evaluate every welfare applicant in the city for potential fraud (MIT Technology Review)
https://www.technologyreview.com/2025/06/1

Inside Amsterdam’s high-stakes experiment to create fair welfare AI
The Dutch city thought it could break a decade-long trend of implementing discriminatory algorithms. Its failure raises the question: can these programs ever be fair?

Expressivity Limits and Trainability Guarantees in Quantum Walk-based Optimization
Guilherme A. Bridi, Debbie Lim, Lirand\"e Pira, Raqueline A. M. Santos, Franklin de L. Marquezino, Soumik Adhikary
https://arxiv.org/abs/2508.05749

Expressivity Limits and Trainability Guarantees in Quantum Walk-based Optimization
Quantum algorithms have emerged as a promising tool to solve combinatorial optimization problems. The quantum walk optimization algorithm (QWOA) is one such variational approach that has recently gained attention. In the broader context of variational quantum algorithms (VQAs), understanding the expressivity and trainability of the ansatz has proven critical for evaluating their performance. A key method to study both these aspects involves analyzing the dimension of the dynamic Lie algebra (DL…

$C^{\infty}$-structures approach to travelling wave solutions to the gKdV equation
Antonio J. Pan-Collantes
https://arxiv.org/abs/2507.07112 https://

$C^{\infty}$-structures approach to travelling wave solutions to the gKdV equation
We present a geometric method for finding travelling wave solutions to the generalized Korteweg--de Vries (gKdV) equation $$ u_t + u_{xxx} + a(u)u_x = 0, $$ where $a(u)$ is a smooth function characterizing the nonlinearity. Using the travelling wave ansatz, the gKdV equation reduces to an ordinary differential equation (ODE), which we analyze via the $\mathcal{C}^\infty$-structure-based method, a geometric framework involving sequences of involutive distributions and Pfaffian equations. Startin…

Reconciling Inflation with Hubble Anisotropies
Brett McInnes
https://arxiv.org/abs/2508.06796 https://arxiv.org/pdf/2508.06796

Reconciling Inflation with Hubble Anisotropies
There have been persistent suggestions, based on several diverse data sets, that the cosmic expansion is not exactly isotropic. It is not easy to develop a coherent theoretical account of such a ``Hubble anisotropy'', for, in standard General Relativity, intuition suggests that it contradicts the predictions of the very successful Inflationary hypothesis. We put this intuition on a firm basis, by proving that if we [a] make use of an Inflationary theory in which Inflation isotropises spatial ge…

Finite-temperature transport in the gapped spin-1/2 XXZ chain and one-dimensional lattice spinless fermion model
J. M. P. Carmelo, P. D. Sacramento
https://arxiv.org/abs/2509.08741

Finite-temperature transport in the gapped spin-1/2 XXZ chain and one-dimensional lattice spinless fermion model
Here we consider a class of energy eigenstates of the spin-1/2 XXZ chain that exist both for anisotropies 1 and larger than 1. We show that at the isotropic point their contributions are behind the diffusion constant being infinite, spin transport being anomalous superdiffusive for temperatures T>0. That for anisotropy larger than 1 such states do not contribute to the diffusion constant is shown to imply it is finite, spin transport being normal diffusive for T>0. By combining the connection t…

The Beauty of Anisotropic Mesh Refinement: Omnitrees for Efficient Dyadic Discretizations
Theresa Pollinger, Masado Ishii, Jens Domke
https://arxiv.org/abs/2508.06316 https://…

The Beauty of Anisotropic Mesh Refinement: Omnitrees for Efficient Dyadic Discretizations
Structured adaptive mesh refinement (AMR), commonly implemented via quadtrees and octrees, underpins a wide range of applications including databases, computer graphics, physics simulations, and machine learning. However, octrees enforce isotropic refinement in regions of interest, which can be especially inefficient for problems that are intrinsically anisotropic--much resolution is spent where little information is gained. This paper presents omnitrees as an anisotropic generalization of octr…

Influence of interstellar environment near the solar system on cosmic-ray spectra and dipole anisotropy
Zhangxi Xue, Siming Liu
https://arxiv.org/abs/2507.07057

Influence of interstellar environment near the solar system on cosmic-ray spectra and dipole anisotropy
Properties of interstellar environment near the solar system have been probed by missions like IBEX, Voyager over the last two decades. Although it has been well recognized that properties of cosmic rays up to the PeV energy can be affected by the local interstellar environment, detailed modeling has not been done. We show that a three component model for the cosmic ray proton and helium spectra from GV to several PV can naturally explain the energy dependence of the dipole anisotropy of cosmic…

Amnesty International, Gaza: Evidence points to Israel’s continued use of starvation to inflict genocide against Palestinians.
https://www.amnesty.org/en/latest/news/2025/07/gaza-evidence-poi…

Gaza: Evidence points to Israel’s continued use of starvation to inflict genocide against Palestinians  
Evidence gathered by Amnesty International demonstrates how over a month since the introduction of its militarized aid distribution system, Israel has continued to use starvation of civilians as a weapon of war against Palestinians in the occupied Gaza Strip and to deliberately impose conditions of life calculated to bring about their physical destruction as part of its ongoing genocide. 

Droplet-gas phases and their dynamical formation in particle imbalanced mixtures
Jose Carlos Pelayo, George A. Bougas, Thom\'as Fogarty, Thomas Busch, Simeon I. Mistakidis
https://arxiv.org/abs/2506.09314

Droplet-gas phases and their dynamical formation in particle imbalanced mixtures
We explore the ground state phase diagram and nonequilibrium dynamics of genuine two-component particle-imbalanced droplets in both isotropic and anisotropic three-dimensional confinements. A gradual transition from mixed droplet-gas to gas configurations is revealed as the average intercomponent attraction decreases or the transverse confinement becomes tighter. Within the mixed structures, a specific majority fragment binds to the minority droplet, satisfying the density ratio locking conditi…

On surface energies in scaling laws for singular perturbation problems for martensitic phase transitions
Angkana R\"uland, Camillo Tissot, Antonio Tribuzio, Christian Zillinger
https://arxiv.org/abs/2507.06773 https://arxiv.org/pdf/2507.06773 https://arxiv.org/html/2507.06773
arXiv:2507.06773v1 Announce Type: new
Abstract: The objective of this article is to compare different surface energies for multi-well singular perturbation problems associated with martensitic phase transformations involving higher order laminates. We deduce scaling laws in the singular perturbation parameter which are robust in the choice of the surface energy (e.g., diffuse, sharp, an interpolation thereof or discrete). Furthermore, we show that these scaling laws do not require the presence of isotropic surface energies but that generically also highly anisotropic surface energies yield the same scaling results. More precisely, the presence of essentially generic partial directional derivatives in the regularization terms suffices to produce the same scaling behaviour as in the isotropic setting. The only sensitive directional dependences are directly linked to the lamination directions of the well structure -- and even for these only the ``inner-most'' lamination direction is of significance in determining the scaling law. In view of experimental applications, this shows that also for higher-order laminates, the precise structure of the surface energies -- which is often very difficult to determine experimentally -- does not have a crucial impact on the scaling behaviour of the investigated structures but only enters when considering finer properties.
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