Tootfinder

Multi-spacecraft Measurements of the Evolving Geometry of the Solar Alfv\'en Surface Over Half a Solar Cycle
Samuel T. Badman, Michael L. Stevens, Stuart D. Bale, Yeimy J. Rivera, Kristopher G. Klein, Tatiana Niembro, Rohit Chhiber, Ali Rahmati, Phyllis L. Whittlesey, Roberto Livi, Davin E. Larson, Christopher J. Owen, Kristoff W. Paulson, Timothy S. Horbury, Jean Morris, Helen O'Brien, Jean-Baptiste Dakeyo, Jaye L. Verniero, Mihailo Martinovic, Marc Pulupa, Federico Fraschetti…

Multi-spacecraft Measurements of the Evolving Geometry of the Solar Alfvén Surface Over Half a Solar Cycle
The geometry of a star's Alfvén surface determines stellar angular momentum loss, separates a causally distinct 'corona' and stellar wind, and potentially affects exoplanetary habitability. The solar Alfvén surface is the only such structure that is directly measurable and since 2021, has been routinely measured in situ by NASA's Parker Solar Probe (Parker). We use these unique measurements in concert with Solar Orbiter and L1 in situ data spanning the first half of the Solar Cycle 25 in time…

A Haldane-Anderson Hamiltonian Model for Hyperthermal Hydrogen Scattering from a Semiconductor Surface
Xuexun Lu, Nils Hertl, Reinhard J. Maurer
https://arxiv.org/abs/2508.13360

A Haldane-Anderson Hamiltonian Model for Hyperthermal Hydrogen Scattering from a Semiconductor Surface
Collisions of atoms and molecules with metal surfaces create electronic excitations in the metal, leading to nonadiabatic energy dissipation, inelastic scattering, and sticking. Mixed quantum-classical molecular dynamics simulation methods, such as molecular dynamics with electronic friction, are able to capture nonadiabatic energy loss during dynamics at metal surfaces. Hydrogen atom scattering on semiconductors, on the other hand, exhibits strong adsorbate-surface energy transfer only when th…

A Screen-printed, Silver-nanowire-based Optically Transparent Wideband Reconfigurable Intelligent Surface for 5G mmWave Applications
Yiming Yang, Mohammad Vaseem, Ruiqi Wang, Behrooz Makki, Atif Shamim
https://arxiv.org/abs/2509.05981

A Screen-printed, Silver-nanowire-based Optically Transparent Wideband Reconfigurable Intelligent Surface for 5G mmWave Applications
The reconfigurable intelligent surface (RIS) can help establish secondary line-of-sight links for 5G mmWave and beyond applications to cater for the large path loss and blockage in millimeter-wave direct links. It is desirable that the RISs are optically transparent so that they can be placed on building windows, etc. However, traditional transparent designs with indium tin oxide films have challenges of high loss and low transparency, while metallic meshes suffer from a large feature size for …

A plasmoid-model for mass loss from stars on the upper red giant branch: The mass loss rate is controlled by the number of density scale heights in the convection zone
J. MacDonald, D. J. Mullan
https://arxiv.org/abs/2508.05480

A plasmoid-model for mass loss from stars on the upper red giant branch: The mass loss rate is controlled by the number of density scale heights in the convection zone
Recent asteroseismic determinations of ΔM, the integrated mass loss on the red giant branch (RGB), for fields stars show a trend of ΔM decreasing as metallicity increases. This trend among field stars is inconsistent with many existing models of RGB mass loss. The present paper is motivated by a 'plasmoid' model of RGB mass loss in which magnetic flux loops, generated by a shear dynamo operating below the convection zone, are buoyed up to the stellar surface starting at the evolutionary stage…

Atmospheric rivers and winter sea ice drive recent reversal in Antarctic ice mass loss
Marlen Kolbe, Jose Abraham Torres Alavez, Ruth Mottram, Marwan Katurji, Richard Bintanja, Eveline C. van der Linden
https://arxiv.org/abs/2510.03590

Atmospheric rivers and winter sea ice drive recent reversal in Antarctic ice mass loss
Since about 2000, the total mass of the Antarctic Ice Sheet (AIS) has declined at a near-linear rate, increasing global sea levels. Since 2016, however, satellite gravimetry data reveal a slowdown in net AIS mass loss and a net mass gain since 2020, despite increases in dynamically-driven ice loss by discharge from outlet glaciers. Here we use a suite of reanalyses and regional climate models to show that this reversal is caused by increased precipitation and positive surface mass balance anoma…

Energy relaxation in superthermal collisions of carbon with oxygen: the influence of isotopic substitution
Cheikh T. Bop, Marko Gacesa
https://arxiv.org/abs/2508.12807 https://

Energy relaxation in superthermal collisions of carbon with oxygen: the influence of isotopic substitution
The transition from a once-dense Martian atmosphere to the thin one observed today implies a substantial loss of carbon, either through atmospheric escape or surface deposition. Accurately modeling this carbon escape necessitates accounting for collisions between energetic carbon atoms and the primary atmospheric constituents, including oxygen. To this end, we computed a highly accurate and comprehensive set of potential energy curves (PECs) for the C($^3$P) + O($^3$P) system. Based on these PE…

LATTA: Langevin-Anchored Test-Time Adaptation for Enhanced Robustness and Stability
Harshil Vejendla
https://arxiv.org/abs/2510.05530 https://arxiv.org/pdf…

LATTA: Langevin-Anchored Test-Time Adaptation for Enhanced Robustness and Stability
Test-time adaptation (TTA) aims to adapt a pretrained model to distribution shifts using only unlabeled test data. While promising, existing methods like Tent suffer from instability and can catastrophically forget the source knowledge, especially with small batch sizes or challenging corruptions. We argue that this arises from overly deterministic updates on a complex loss surface. In this paper, we introduce Langevin-Anchored Test-Time Adaptation (LATTA), a novel approach that regularizes ada…

Here are my favourites from the National Portrait Gallery's Portrait Award 2025. It's a fantastic selection this year, and free to see as always.
#art #portraits #painting

Searching for Stellar-Feedback-Driven Outflow Signatures: A Deep Dive into NGC 3741
Lexi N. Gault, Liese van Zee, Elizabeth A. K. Adams, James M. Wells, Laura Congreve Hunter, Kristen B. W. McQuinn, Roger E. Cohen, O. Grace Telford
https://arxiv.org/abs/2510.12645

Searching for Stellar-Feedback-Driven Outflow Signatures: A Deep Dive into NGC 3741
Stellar feedback drives winds and outflows critical to the baryon cycles of low-mass galaxies whose shallow gravitational potential wells make them particularly susceptible to mass and metal loss through outflows. However, spatially resolved observations of stellar-feedback-driven outflows are limited due to their low-surface brightness and transient nature. We present the pilot of a larger multi-wavelength study searching for and quantifying stellar-feedback-driven winds and outflows on both s…

A 5.9 GHz Sezawa SAW Acoustic Delay Line Based on Al0.6Sc0.4N-on-Sapphire with Propagation Q-factor > 3,000
Chin-Yu Chang, Xiaolei Tong, Pedram Yousefian, Ella Klein, Xingyu Du, Roy H. Olsson III
https://arxiv.org/abs/2509.12480

A 5.9 GHz Sezawa SAW Acoustic Delay Line Based on Al0.6Sc0.4N-on-Sapphire with Propagation Q-factor > 3,000
In this work, we demonstrate a high-performance surface acoustic wave (SAW) delay line based on a Scandium alloyed aluminum nitride (AlScN)-on-sapphire platform operating at 5.9 GHz with an exceptionally high acoustic propagation Q-factor. An 800 nm AlScN thin film with 40% scandium alloying concentration was deposited on a thick sapphire substrate to achieve strong acoustic energy confinement and large electromechanical coupling effect, thereby minimizing the insertion loss (IL) and propagatio…

Active IRS-Enabled Integrated Sensing and Communications with Extended Targets
Yuan Fang, Xianxin Song, Huazhou Hou, Ziguo Zhong, Xianghao Yu, Jie Xu, Yongming Huang
https://arxiv.org/abs/2508.00379

Active IRS-Enabled Integrated Sensing and Communications with Extended Targets
This paper studies the active intelligent reflecting surface (IRS)-enabled integrated sensing and communications (ISAC), in which an active IRS is deployed to assist the base station (BS) in serving multiple communication users (CUs) and simultaneously sensing an \emph{extended} target at the non-line-of-sight (NLoS) area of the BS. The active IRS has the capability of amplifying the reflected signals so as to overcome significant reflection path loss in NLoS communication and sensing. In parti…

Effect of Matter Accretion on Lithium Enhancement of Giants
Xuefeng Li, Jianrong Shi, Yan Li, Hongliang Yan, Jinghua Zhang, Fei Guo
https://arxiv.org/abs/2508.00405 https://

Effect of Matter Accretion on Lithium Enhancement of Giants
A subset of low-mass giants ($<2.2\,M_{\odot}$) exhibit anomalous lithium enhancement behavior, which is still an open topic. Given that more massive giants retain more surface lithium, increasing mass by accreting circumstellar matter could be a channel to enrich lithium. We evaluate this process in the current work. Using MESA, we construct a model of matter accretion, including mass loss, that evolves a star from the main sequence turnoff to the red giant branch tip. The mean accretion rate …