Tootfinder

Spiraling light: Generating optical tornados
Dimitris Mansour, Apostolos Brimis, Konstantinos G. Makris, Dimitris G. Papazoglou
https://arxiv.org/abs/2509.12088 https://

Spiraling light: Generating optical tornados
We experimentally generate optical tornado waves using spatial multiplexing on a single-phase modulation device. In their focal region, the intensity pattern outlines a spiral of decreasing radius and pitch. We examine the propagation dynamics of such novel waves and reveal the key factors that lead to angular acceleration. Moreover, we propose a two-color scheme that makes it possible to generate dynamically twisting light, an optical analog of a drill, that can rotate at THz frequencies.

Investigation of particle dynamics and classification mechanism in a spiral jet mill through computational fluid dynamics and discrete element methods
Simone Bn\`a, Raffaele Ponzini, Mirko Cestari, Carlo Cavazzoni, Ciro Cottini, Andrea Benassi
https://arxiv.org/abs/2509.06965

Investigation of particle dynamics and classification mechanism in a spiral jet mill through computational fluid dynamics and discrete element methods
Predicting the outcome of jet-milling based on the knowledge of process parameters and starting material properties is a task still far from being accomplished. Given the technical difficulties in measuring thermodynamics, flow properties and particle statistics directly in the mills, modelling and simulations constitute alternative tools to gain insight in the process physics and many papers have been recently published on the subject. An ideal predictive simulation tool should combine the cor…

Wave-like Spiral Interactions and the Emergence of Quasi-Biennial Oscillations in Strato-Rotational Flows
Gabriel Meletti, St\'ephane Abide, St\'ephane Viazzo, Jezabel Curbelo, Uwe Harlander
https://arxiv.org/abs/2509.06691

Wave-like Spiral Interactions and the Emergence of Quasi-Biennial Oscillations in Strato-Rotational Flows
This study investigates the dynamics of Strato-Rotational Instability (SRI) in a stratified, rotating fluid, focusing on the interaction between axial modes and spiral components. Through numerical analysis, we find that SRI induces oscillatory behaviors that change the mean flow, leading to the selective activation of distinct axial wavenumbers associated with upward and downward propagating spiral modes. These results suggest wave-mean flow interactions. The use of Radon Transforms (RT) allow…

Cosmological simulations of the same spiral galaxy: satellite properties, the role of baryonic physics and star formation history in shaping dark matter cores/cusps
A. Nu\~nez-Casti\~neyra, E. Nezri, P. Mollitor, L. Michel-Dansac, J. Devriendt, R. Teyssier
https://arxiv.org/abs/2509.07470

Cosmological simulations of the same spiral galaxy: satellite properties, the role of baryonic physics and star formation history in shaping dark matter cores/cusps
We investigate the role of baryonic physics in shaping the population, structure, and internal dynamics of galactic subhalos using the Mochima suite of cosmological zoom-in simulations. A refined method is developed to identify bound subhalo material by isolating the local gravitational potential and applying multi-criteria phase-space selection. This approach enables a robust characterisation of subhalo properties across five baryonic runs with varying prescriptions for star formation, and sup…

Coarsening dynamics for spiral and nonspiral waves in active Potts models
Hiroshi Noguchi
https://arxiv.org/abs/2509.17408 https://arxiv.org/pdf/2509.17408…

Coarsening dynamics for spiral and nonspiral waves in active Potts models
This study examines the domain-growth dynamics of $q$-state active Potts models ($q = 3$--$8$) under the cyclically symmetric conditions using Monte Carlo simulations on square and hexagonal lattices. By imposing active cyclic flipping of states, finite-length waves emerge in the long-term limit. This study focuses on coarsening dynamics from an initially random mixture of states to these moving-domain states. When spiral waves appear in the final state, the correlation length follows the Lifsh…

Exponential Dichotomies in Higher-Dimensional Spatial Dynamics for Elliptic Partial Differential Equations
Margaret Beck, Ryan Goh, Alanna Haslam-Hyde
https://arxiv.org/abs/2510.00917

Exponential Dichotomies in Higher-Dimensional Spatial Dynamics for Elliptic Partial Differential Equations
Exponential dichotomies, when they exist, provide powerful information about the structure of bounded solutions even in the case of an ill-posed evolutionary equation. The method of spatial dynamics, in which one views a spatial variable as a time-like evolutionary variable, allows for the use of classical dynamical systems techniques, such as exponential dichotomies, in broader contexts. This has been utilized to study stationary, traveling wave, time-periodic, and spiral wave solutions of PDE…

Crosslisted article(s) found for physics.app-ph. https://arxiv.org/list/physics.app-ph/new
[1/1]:
- Investigation of particle dynamics and classification mechanism in a spiral jet mill through comp...
Simone Bn\`a, Raffaele Ponzini, Mirko Cestari, Carlo Cavazzoni, Ciro Cott…

Spontaneous spiral patterns etched on Germanium
Yilin Wong, Giovanni Zocchi
https://arxiv.org/abs/2508.16764 https://arxiv.org/pdf/2508.16764

Spontaneous spiral patterns etched on Germanium
Thin metal film on Germanium, in the presence of water, results in a remarkable pattern forming system. Here we present an analysis of spirals spontaneously etched on the Ge surface. We obtain measurements of the growth dynamics of the spirals and measurements of the local strain field in the metal film. Both indicate that the near geometric order of the pattern originates from the unique far field of a singularity - a crystal defect. The measured engraving profile is found in quantitative agre…

Crosslisted article(s) found for nlin.PS. https://arxiv.org/list/nlin.PS/new
[1/1]:
- Coarsening dynamics for spiral and nonspiral waves in active Potts models
Hiroshi Noguchi

Galactic Contrail in NGC 3627 caused by Dwarf Galaxy Candidate or Massive Black Hole Flyby
Mengke Zhao, Guang-Xing Li
https://arxiv.org/abs/2509.20832 https://

Galactic Contrail in NGC 3627 caused by Dwarf Galaxy Candidate or Massive Black Hole Flyby
We report the discovery of a kpc scale molecular contrail in the spiral galaxy NGC 3627, a narrow structure spanning 8 kpc in length with a width of 200 pc and an extreme aspect ratio of 40, observed in both mid-infrared dust emission (PHANGS-JWST) and CO(2-1) gas (PHANGS-ALMA). This contrail size significantly exceeds the size of any known analogs in the Milky Way and exhibits supersonic turbulence (10 km/s). Its morphology and dynamics are consistent with gravitational focusing by a flyby com…