87191 research outputs found
Sort by
An analytic result for the 0 → ggHHH amplitude
No full textWe present a fully analytic calculation of the leading-order one-loop amplitude for triple Higgs production via gluon fusion, gg → HHH, retaining full dependence on the mass of the heavy quark circulating in the loop. This amplitude provides a direct probe of the triple and quartic Higgs self-couplings, the measurement of which is a central goal of current and future colliders. The amplitude can be presented in compact form thanks to the use of analytic reconstruction techniques, based on finite-field and p-adic evaluations, multivariate partial fraction decompositions, and primary decompositions to identify common numerator factors. Although full analytic results are given in the text and in the supplementary material, the main thrust of this paper is to further test and illustrate these analytic reconstruction techniques in a concrete physical example. Our results provide a compact and efficient representation of the matrix element for this process, enabling evaluations that are more than an order of magnitude faster than existing numerical alternatives. Full analytic control of the leading-order, loop-induced amplitude is an important step towards handling more complex 2-loop or real-radiation corrections to this and related processes
Spiral Structure Properties, Dynamics, and Evolution in Milky Way–mass Galaxy Simulations
No full textThe structure of spiral galaxies is essential to understanding the dynamics and evolution of disk galaxies; however, the precise nature of spiral arms remains uncertain. Two challenges in understanding the mechanisms driving spirals are how galactic environment impacts spiral morphology and how they evolve over time. We present a catalog characterizing the properties, dynamics, and evolution of m = 2 spiral structure in 10 Milky Way–mass galaxies from the FIRE-2 cosmological zoom-in simulations. Consistent with previous literature, we find that FIRE-2 spirals are transient, recurring features simultaneously present in the disk at varying pattern speeds (Ωp) that broadly decrease with radius. These spirals persist on gigayear timescales (mean duration of 1.90 Gyr), but fluctuate in amplitude on timescales of hundreds of millions of years. Tidal interactions and bar episodes impact the resulting m = 2 spiral structure: strong satellite interactions generally produce shorter-lived, stronger spirals with larger radial extent, and bars can increase Ωp. Galactic environment influences spiral structure, in which kinematically colder disks can support longer-lived, stronger spirals. The properties of identified spirals in FIRE-2 vary widely in radial extent (0.3–10.8 kpc), duration (1.00–6.00 Gyr), and amplitude (a2,max = 0.018–0.192). We find the presence of spirals in all age populations, suggesting these are density-wave-driven features. This work represents the first time that spiral structure has been cataloged in this manner in cosmological simulations; the catalog can be leveraged with current and forthcoming observational surveys, enabling systematic comparisons to further our understanding of galaxy evolution
Analysis of untrusted-node quantum key distribution from a geostationary satellite
Get PDFIn pursuit of a global quantum key distribution (QKD) network, a service based on untrusted nodes on geostationary satellites could offer wide coverage, continuous operation, and enhanced security compared to the trusted node alternative. Although this scenario has been studied for entanglement-based protocols, such an approach would require large-area telescopes both on the ground and in space. In this work, we analyze the performance of two QKD protocols well adapted to this scenario, namely twin-field (TF) and mode-pairing (MP) QKD, which exhibit high resilience to high-loss channels. Leveraging an in-depth simulation of communication channels corrected with adaptive optics, we assess the expected secret key rates for both protocols in a configuration involving two 50 cm telescopes on board the satellite and ground-based telescopes ranging from 20 cm to 1 m in aperture. Our results show that, in the best case and considering realistic detectors, it is possible to achieve secret key rates on the order of a few 100 bit s−1 for both TF and MP-QKD. We show, notably, that secret key generation is potentially feasible even with 20 cm ground telescopes, highlighting the high scalability potential of such a configuration
"The Silken Skilled Transmemberment of Song": Shelley, Romantic Visionary Quest, and the Poetry of Hart Crane
Get PDFTaking seriously the critical estimations of Harold Bloom and Michael O’Neill that Hart Crane is the true American inheritor of Shelley’s poetic legacy, my article explores the theme of Romantic visionary quest in Crane’s poetry. I argue that this peculiarly Shelleyan motif of visionary quest in Crane’s “Repose of Rivers”, “Praise for an Urn”, “Voyages”, “The Harbour Dawn”, and “Atlantis” acts as a prism through which to view Crane’s imaginative entanglements with the poetry of Wordsworth, Byron, and Keats
The Discovery Research Platform for Medical Humanities responds to the Wellcome Trust’s report on Archives, manuscripts and material culture (AMCs) in life, health, and wellbeing research
Get PDFThis open letter from Durham University’s Discovery Research Platform for Medical Humanities responds to the Wellcome Trust’s 2025 report on archives, manuscripts, and material culture (AMCs) in health research. We applaud the report’s recognition of AMCs as foundational infrastructures for discovery research and its emphasis on pluralistic values, and we use this letter to expand upon three critical dimensions. First, we reinforce the point that medical humanities work with AMCs generates transformational biomedical and cultural knowledge capable of effecting real-world reform, exemplified by recent challenges to race-based lung capacity evaluations citing Platform research. Second, we urge caution regarding digitisation initiatives, particularly concerning A.I. training using existing collections, emphasising the need for ethical consideration of environmental impact, intellectual property, and the perpetuation of structural inequities in digital infrastructure. Third, we advocate for expansive definitions of health-related material culture beyond biomedical paradigms, encompassing artistic collections and emphasising the irreplaceable value of sensory and affective experiences in hands-on collections work. We draw attention to the tensions inherent in the use of digital surrogates, which, though vital for accessibility, cannot fully replace original collections. We conclude by emphasising the Platform’s commitment to further collaborative work to transform the report’s recommendations into sustainable practice
Artificial intelligence transformations in geotechnics: progress, challenges and future enablers
No full textOur reliance on the underground space to deliver critical civil engineering infrastructure is growing: to accommodate utility and transport infrastructure in urban environments, to provide innovative housing and commercial solutions, and to support proliferating renewable energy infrastructure, particularly offshore. Artificial intelligence (AI) is arguably the most promising enabler to transform geotechnical engineering by extracting knowledge from data to achieve step-change increases in efficiency, sustainability, reliability and safety. This paper seeks to develop a shared understanding of the state of the art of AI in geotechnics and to explore future developments. By way of example, specific popular use cases in geotechnics are considered to highlight current progress in AI applications including intelligent site investigation, predictive modelling for soil behaviour, and optimisation of design and construction processes. The paper then addresses key research challenges, such as data scarcity and interpretability, and discusses the opportunities that lie ahead in the integration of AI with geotechnical engineering. Finally, priority technological enablers are identified for future transformations
The lexicon adapts to competing communicative pressures: Explaining patterns of word similarity
Get PDFCross-linguistically, lexicons tend to be more phonetically clustered than required by the phonotactics of the language; that is, words within a language are more similar to each other than they need to be. In this study, we investigate how this property evolves under the influence of competing communicative pressures: a production-side pressure to re-use more easily articulated sounds, and a comprehension-side pressure for distinctiveness of wordforms. In an exemplar-based computational model and a communication experiment using a miniature artificial language, we show that natural-language-like levels of clustering emerge from a trade-off between these pressures. With only one pressure at work, the resulting lexicons tend to inhabit an extreme region of the possible design space: production pressures alone give rise to maximally clustered lexicons, while comprehension pressures alone give rise to maximally disperse lexicons. We also test whether clustering emerges more strongly for high-frequency items, but our results lend support only to a weak relationship between frequency and clustering. Overall, this study adds to a growing body of evidence showing that mechanisms operating at the level of individual language users and individual episodes of communication can give rise to emergent structural properties of language
Data sources:
Access Repository Dashboard
Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇