Tootfinder

The double neutron star PSR J1946 2052 I. Masses and tests of general relativity
Lingqi Meng, Paulo C. C. Freire, Kevin Stovall, Norbert Wex, Xueli Miao, Weiwei Zhu, Michael Kramer, James M. Cordes, Huanchen Hu, Jinchen Jiang, Emilie Parent, Lijing Shao, Ingrid H. Stairs, Mengyao Xue, Adam Brazier, Fernando Camilo, David J. Champion, Shami Chatterjee, Fronefield Crawford, Ziyao Fang, Qiuyang Fu, Yanjun Guo, Jason W. T. Hessels, Maura MacLaughlin, Chenchen Miao, Jiarui Niu, Ziwei Wu, Ju…

The double neutron star PSR J1946+2052 I. Masses and tests of general relativity
We conducted high-precision timing of PSR J1946+2052 to determine the masses of the two neutron stars in the system, test general relativity (GR) and assessed the system's potential for future measurement of the moment of inertia of the pulsar. We analysed seven years of timing data from the Arecibo 305-m radio telescope, the Green Bank Telescope (GBT), and the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The data processing accounted for dispersion measure variations and relat…

Designing Control Barrier Functions Using a Dynamic Backup Policy
Victor Freire, Marco M. Nicotra
https://arxiv.org/abs/2510.09810 https://arxiv.org/pdf/25…

Designing Control Barrier Functions Using a Dynamic Backup Policy
This paper presents a systematic approach to construct control barrier functions for nonlinear control affine systems subject to arbitrary state and input constraints. Taking inspiration from the reference governor literature, the proposed method defines a family of backup policies, parametrized by the equilibrium manifold of the system. The control barrier function is defined on the augmented state-and-reference space: given a state-reference pair, the approach quantifies the distance to const…

🇺🇦 #NowPlaying on BBCRadio3's #EssentialClassics
Nelson Freire & Robert Schumann:
🎵 Arabeske in C major Op.18
#NelsonFreire #RobertSchumann
https://open.spotify.com/track/6R9wAhhVzUB2LMNBxf15PE

First Proton-Induced Cross Sections on a Stored Rare Ion Beam: Measurement of 118Te(p,{\gamma}) for Explosive Nucleosynthesis
F. Dellmann, J. Glorius, Yu. A. Litvinov, R. Reifarth, L. Varga, M. Aliotta, F. Amjad, K. Blaum, L. Bott, C. Brandau, B. Br\"uckner, C. G. Bruno, R. -J. Chen, T. Davinson, T. Dickel, I. Dillmann, D. Dmytriev, P. Erbacher, O. Forstner, D. Freire-Fern\'andez, H. Geissel, K. G\"obel, C. J. Griffin, R. E. Grisenti, A. Gumberidze, E. Haettner, S. Hagman…

First Proton-Induced Cross Sections on a Stored Rare Ion Beam: Measurement of 118Te(p,γ) for Explosive Nucleosynthesis
We present the first nuclear cross-section measurements of (p,γ) and (p,n) reactions on 118Te at energies relevant for the γ-process nucleosynthesis. Absolute cross-section values for center-of-mass energies of 6, 7 and 10 MeV are provided, together with a theoretical extrapolation to the Gamow window. This experiment marks the first time that direct proton-induced reactions have been measured on a radioactive ion beam at the Experimental Storage Ring (ESR) at GSI, Darmstadt. This paves the w…

Wrong Face, Wrong Move: The Social Dynamics of Emotion Misperception in Agent-Based Models
David Freire-Obreg\'on
https://arxiv.org/abs/2509.00080 https://

Wrong Face, Wrong Move: The Social Dynamics of Emotion Misperception in Agent-Based Models
The ability of humans to detect and respond to others' emotions is fundamental to understanding social behavior. Here, agents are instantiated with emotion classifiers of varying accuracy to study the impact of perceptual accuracy on emergent emotional and spatial behavior. Agents are visually represented with face photos from the KDEF database and endowed with one of three classifiers trained on the JAFFE (poor), CK+ (medium), or KDEF (high) datasets. Agents communicate locally on a 2D toroida…

Psychological safety in software workplaces: A systematic literature review
Beatriz Santana, Lidiv\^anio Monte, Bianca Santana de Ara\'ujo Silva, Glauco Carneiro, S\'avio Freire, Jos\'e Amancio Macedo Santos, Manoel Mendon\c{c}a
https://arxiv.org/abs/2508.03369

Psychological safety in software workplaces: A systematic literature review
Context: Psychological safety (PS) is an important factor influencing team well-being and performance, particularly in collaborative and dynamic domains such as software development. Despite its acknowledged significance, research on PS within the field of software engineering remains limited. The socio-technical complexities and fast-paced nature of software development present challenges to cultivating PS. To the best of our knowledge, no systematic secondary study has synthesized existing kn…

Characterization of Lattice Properties Within Modal Extensions
Alfredo R. Freire (Department of Philosophy, University of Brasilia, Brasil), Manuel A. Martins (Department of Mathematics, University of Aveiro, Portugal)
https://arxiv.org/abs/2509.25882

Characterization of Lattice Properties Within Modal Extensions
This paper investigates the extension of lattice-based logics into modal languages. We observe that such extensions admit multiple approaches, as the interpretation of the necessity operator is not uniquely determined by the underlying lattice structure. The most natural interpretation defines necessity as the meet of the truth values of a formula across all accessible worlds -- an approach we refer to as the \textitnormal interpretation. We examine the logical properties that emerge under this…

Existence and Nonexistence Breaking Results For a Weighted Elliptic Problem in Half-Space
J. M. Do \'O, R. F. Freire, J. Giacomoni, E. S. Medeiros
https://arxiv.org/abs/2510.05999

Existence and Nonexistence Breaking Results For a Weighted Elliptic Problem in Half-Space
In this paper we study the problem $-\mathrm{div}(ρ(x_N)\nabla u)=a|u|^{p-2}u$ in $\mathbb{R}^N_+$, $-\partial u/\partial x_N=b|u|^{q-2}u$ in $\mathbb{R}^{N-1}$ where $a,b \in \mathbb{R}$, $p,q\in (1,\infty)$ and $ρ$ is a positive weight. We establish regularity results for weak solutions and, using a variational approach combined with a new Pohozaev-type identity, we show that the introduction of the weighted operator $-\mathrm{div}(ρ(x_N)\nabla u)$ can reverse the known…

Efficiency of the superconducting diode effect of pair-density-wave states in two-dimensional $d$-wave altermagnets
Igor de M. Froldi, Hermann Freire
https://arxiv.org/abs/2510.07506

Efficiency of the superconducting diode effect of pair-density-wave states in two-dimensional $d$-wave altermagnets
We systematically study the efficiency of the intrinsic superconducting diode effect of several pair-density-wave states that can emerge in two-dimensional $d$-wave metallic altermagnets. To this end, we investigate several scenarios using an effective minimal microscopic model and Ginzburg-Landau analysis in order to derive the corresponding pairing phase diagrams. In addition, we examine also whether the presence of a Rashba spin-orbit coupling and an applied external magnetic field are benef…

Millisecond Pulsars in M2: New discoveries and a detailed timing analysis
Baoda Li, Kuo Liu, Lin Wang, Shunyi Lan, P. C. C. Freire, Pinsong Zhao, Liyun Zhang, Zhengwei Liu, Lei Qian, Wu Jiang, Dejiang Yin, Yaowei Li, Yinfeng Dai, Yang Liu, Xiangcun Meng, Zhichen Pan
https://arxiv.org/abs/2508.06726…

Millisecond Pulsars in M2: New discoveries and a detailed timing analysis
Globular clusters (GCs) offer a unique environment for discovering and studying millisecond pulsars. In this paper, we present a multi-epoch search and detailed timing analysis of millisecond pulsars in the GC M2, using the Five-hundred-meter Aperture Spherical Telescope. We have discovered two new binary millisecond pulsars in M2, designated M2F and M2G, respectively. We provide measurements of the emission properties of all known pulsars in M2, including their polarization profiles, rotation …

Pattern formation in a coupled driven diffusive system
G. E. Freire Oliveira, R. Dickman, M. O. Lavrentovich, R. K. P. Zia
https://arxiv.org/abs/2509.00220 https://

Pattern formation in a coupled driven diffusive system
We investigate pattern formation in a driven mixture of two repulsive particles by introducing a Field-based Lattice Model (FLM), a hybrid model that combines aspects of the driven Widom-Rowlison lattice gas (DWRLG) and its statistical field theory \cite{DWRLG1,DWRLG2}. We find that the FLM effectively captures the bulk behavior of the DWRLG in both low- and high-density phases, suggesting that phase transitions in these models may share a universality class. Under the effect of the drive, the …

Efficient and Robust Semantic Image Communication via Stable Cascade
Bilal Khalid, Pedro Freire, Sergei K. Turitsyn, Jaroslaw E. Prilepsky
https://arxiv.org/abs/2507.17416

Efficient and Robust Semantic Image Communication via Stable Cascade
Diffusion Model (DM) based Semantic Image Communication (SIC) systems face significant challenges, such as slow inference speed and generation randomness, that limit their reliability and practicality. To overcome these issues, we propose a novel SIC framework inspired by Stable Cascade, where extremely compact latent image embeddings are used as conditioning to the diffusion process. Our approach drastically reduces the data transmission overhead, compressing the transmitted embedding to just …

BDIViz: An Interactive Visualization System for Biomedical Schema Matching with LLM-Powered Validation
Eden Wu, Dishita G Turakhia, Guande Wu, Christos Koutras, Sarah Keegan, Wenke Liu, Beata Szeitz, David Fenyo, Cl\'audio T. Silva, Juliana Freire
https://arxiv.org/abs/2507.16117

BDIViz: An Interactive Visualization System for Biomedical Schema Matching with LLM-Powered Validation
Biomedical data harmonization is essential for enabling exploratory analyses and meta-studies, but the process of schema matching - identifying semantic correspondences between elements of disparate datasets (schemas) - remains a labor-intensive and error-prone task. Even state-of-the-art automated methods often yield low accuracy when applied to biomedical schemas due to the large number of attributes and nuanced semantic differences between them. We present BDIViz, a novel visual analytics sy…

Project-connex Decompositions and Tractability of Aggregate Group-by Conjunctive Queries
Diego Figueira, Cibele Freire
https://arxiv.org/abs/2507.14101 htt…

Project-connex Decompositions and Tractability of Aggregate Group-by Conjunctive Queries
We introduce 'project-connex' tree-width as a measure of tractability for counting and aggregate conjunctive queries over semirings with 'group-by' projection (also known as 'AJAR' or 'FAQ' queries). This elementary measure allows to obtain comparable complexity bounds to the ones obtained by previous structural conditions tailored for efficient evaluation of semiring aggregate queries, enumeration algorithms of conjunctive queries, and tractability of counting answers to conjunctive queries. …

TiVy: Time Series Visual Summary for Scalable Visualization
Gromit Yeuk-Yin Chan, Luis Gustavo Nonato, Themis Palpanas, Cl\'audio T. Silva, Juliana Freire
https://arxiv.org/abs/2507.18972

TiVy: Time Series Visual Summary for Scalable Visualization
Visualizing multiple time series presents fundamental tradeoffs between scalability and visual clarity. Time series capture the behavior of many large-scale real-world processes, from stock market trends to urban activities. Users often gain insights by visualizing them as line charts, juxtaposing or superposing multiple time series to compare them and identify trends and patterns. However, existing representations struggle with scalability: when covering long time spans, leading to visual clut…

Optimizing HERON for 100 PeV Neutrino Detection
Andrew Zeolla, Ingo Allekotte, Jaime Alvarez-Mu\~niz, Sergio Cabana-Freire, Valentin Decoene, Luciano Ferreyro, Ars\`ene Ferri\`ere, Matias Hampel, Kumiko Kotera, Olivier Martineau-Huynh, Valentin Niess, Federico Sanchez, Stephanie Wissel
https://arxiv.org/abs/2509.15413

Optimizing HERON for 100 PeV Neutrino Detection
The Hybrid Elevated Radio Observatory for Neutrinos (HERON) is designed to target the astrophysical flux of Earth-skimming tau neutrinos at 100 PeV. HERON consists of multiple compact, phased radio arrays embedded within a larger sparse array of antennas, located on the side of a mountain. This hybrid design provides both excellent sensitivity and a sub-degree pointing resolution. To design HERON, a suite of simulations accounting for tau propagation, shower development, radio emission, and ant…

Are Virtual DES Images a Valid Alternative to the Real Ones?
Ana C. Perre, Lu\'is A. Alexandre, Lu\'is C. Freire
https://arxiv.org/abs/2508.15594 https://

Are Virtual DES Images a Valid Alternative to the Real Ones?
Contrast-enhanced spectral mammography (CESM) is an imaging modality that provides two types of images, commonly known as low-energy (LE) and dual-energy subtracted (DES) images. In many domains, particularly in medicine, the emergence of image-to-image translation techniques has enabled the artificial generation of images using other images as input. Within CESM, applying such techniques to generate DES images from LE images could be highly beneficial, potentially reducing patient exposure to …