Tootfinder

The proposed sell-off of federal lands in the Senate budget bill includes a LOT of Joshua tree habitat—the trees grow in some of the largest areas of undeveloped land in the lower 48 states
The place where eastern and western Joshua trees hybridize, north of Creech AFB, is included
#JoshuaTree #USpolitics

Mario Guevara, an El Salvador-born journalist who covers immigration raids, may face deportation after his arrest while covering No Kings protests in Atlanta (CNN)
http://www.cnn.com/2025/06/17/media/mario-guevara-salvadoran-jo…

Salvadoran journalist arrested while streaming a ‘No Kings’ protest could face deportation
ICE has requested an immigration “detainer” for Mario Guevara, the first step towards potentially deporting the El Salvador-born reporter, his lawyer said.

Parsimonious Compactly Supported Covariance Models in the Gauss Hypergeometric Class: Identifiability, Reparameterizations, and Asymptotic Properties
Moreno Bevilacqua, Christian Caama\~no-Carrillo, Tarik Faouzi, Xavier Emery
https://arxiv.org/abs/2506.13646

Parsimonious Compactly Supported Covariance Models in the Gauss Hypergeometric Class: Identifiability, Reparameterizations, and Asymptotic Properties
We study the covariance model belonging to the Gauss hypergeometric ($GH$) class, a highly flexible and compactly supported correlation model (kernel). This class includes the well-known Generalized Wendland ($GW$) and Matérn ($MT$) kernels as special cases. First, we provide necessary and sufficient conditions for the validity of the $\mathcal{GH}$ model. We then demonstrate that this family of models suffers from identifiability issues under both increasing and fixed-domain asymptotics. To…

Some Structures arising from the Farey Fractal
Shai Haran
https://arxiv.org/abs/2509.10959 https://arxiv.org/pdf/2509.10959

Some Structures arising from the Farey Fractal
This work explores new arithmetic and combinatorial structures arising from the interplay between Farey-type graphs, Fibonacci expansions, and operadic constructions. We introduce Fibonadic numbers, defined as an inverse limit under the Zeckendorf shift, equipped with a metric, order, and commutative rig structure. A normalization lemma provides canonical representatives, while quotients of the non-zero Fibonadic numbers under shifts and it's fundamental domain covering the circle via phi-value…

Taylors hypothesis and its impact on flux measurements in a forest clearcut
Subharthi Chowdhuri, Ivan Mammarella, Olli Peltola
https://arxiv.org/abs/2507.12069

Taylors hypothesis and its impact on flux measurements in a forest clearcut
Taylors hypothesis is the backbone to convert observations done over time to spatial information of the flow while carrying out turbulence measurements on a micrometeorological tower. To address its validity over a highly heterogeneous forest clearcut surface, we utilize an extensive Distributed Temperature Sensing (DTS) and Eddy Covariance (EC) datasets. The DTS measured space-time correlation curves of temperature fluctuations are used to compute the bulk convective speeds of temperature stru…

Dimension-Free Bounds for Generalized First-Order Methods via Gaussian Coupling
Galen Reeves
https://arxiv.org/abs/2508.10782 https://arxiv.org/pdf/2508.10…

Dimension-Free Bounds for Generalized First-Order Methods via Gaussian Coupling
We establish non-asymptotic bounds on the finite-sample behavior of generalized first-order iterative algorithms -- including gradient-based optimization methods and approximate message passing (AMP) -- with Gaussian data matrices and full-memory, non-separable nonlinearities. The central result constructs an explicit coupling between the iterates of a generalized first-order method and a conditionally Gaussian process whose covariance evolves deterministically via a finite-dimensional state ev…

Iterative Annealing Mechanism for Protein and RNA Chaperones
Changbong Hyeon, D. Thirumalai
https://arxiv.org/abs/2506.12645 https://…

Iterative Annealing Mechanism for Protein and RNA Chaperones
Molecular chaperones are machines that consume copious amount of ATP to drive misfolded proteins or RNA to fold into functionally competent native states. Because the folding landscapes of biomolecules with complex native state topology are rugged consisting of multiple minima that are separated by large free energy barriers, folding occurs by the kinetic partitioning mechanism according to which only a small fraction of the molecules reach the folded state in biologically viable times. The res…

Recursive Bound-Constrained AdaGrad with Applications to Multilevel and Domain Decomposition Minimization
Serge Gratton, Alena Kopani\v{c}\'akov\'a, Philippe Toint
https://arxiv.org/abs/2507.11513

Recursive Bound-Constrained AdaGrad with Applications to Multilevel and Domain Decomposition Minimization
Two OFFO (Objective-Function Free Optimization) noise tolerant algorithms are presented that handle bound constraints, inexact gradients and use second-order information when available.The first is a multi-level method exploiting a hierarchical description of the problem and the second is a domain-decomposition method covering the standard addditive Schwarz decompositions. Both are generalizations of the first-order AdaGrad algorithm for unconstrained optimization. Because these algorithms shar…

Frechet and Mordukhovich Derivative (Coderivative) and Covering Constant for Single-Valued Mapping in Euclidean Space with Applications (I)
Jinlu Li
https://arxiv.org/abs/2508.10766

Frechet and Mordukhovich Derivative (Coderivative) and Covering Constant for Single-Valued Mapping in Euclidean Space with Applications (I)
In this paper, we study Frechet derivatives and Mordukhovich derivatives (or coderivatives) of single-valued mappings in Euclidean spaces. At first, we prove the guideline for calculating the Frechet derivatives of single-valued mappings by their partial derivatives. Then, by using the connections between Frechet derivatives and Mordukhovich derivatives (or coderivatives) of single-valued mappings in Banach spaces, we derive the useful rules for calculating the Mordukhovich derivatives of singl…

Projective limits in Euclidean quantum field theory, I: Free scalar fields
Svetoslav Zahariev
https://arxiv.org/abs/2509.12498 https://arxiv.org/pdf/2509.1…

Projective limits in Euclidean quantum field theory, I: Free scalar fields
We present two constructions of projective systems of measures associated to discretizations of free scalar Euclidean quantum fields. The first one is obtained using only purely combinatorial data and applies to free massless scalar fields on polyhedral cell complexes. The second construction utilizes the suitably discretized covariance of the free massive scalar field on a compact Riemannian manifold.