32151 research outputs found
Sort by
Ready-made bodily sensations
Get PDFFunding: Templeton Religion Trust, TRT-2021-10512, awarded to Brendan WolfeEmbodiment plays an important role in art engagement, yet it is unclear how expectations shape bodily sensations, especially when interacting with ready-made art. In this study, we investigated how expectations and the nature of images of everyday objects affect bodily sensations. We tested if bodily sensations changed depending on (1) whether the participants were told that everyday objects were from a Museum, Commercial or Mixed context and (2) the nature of the images, counterbalancing whether they were of ready-made art or not. To measure bodily sensations, we asked participants to self-report their feelings of activity getting stronger (activations) or weaker (deactivations) in their body by clicking on body silhouettes after viewing the images, a methodology called bodily sensation mapping (BSM). We found that bodily activity in the Chest and Upper Limbs areas was influenced by expectations induced by context only. At the same time, Head and Abdomen activations and Chest, Lower and Upper Libs deactivations were solely impacted by the image type. Our innovative Open Science approach to BSMs image analysis revealed how both context and image type were influenced by the activity type, contributing and enriching the ongoing debate regarding the uniqueness of art experiences and aesthetic cognition.Peer reviewe
Reconciling extragalactic star formation efficiencies with theory : insights from PHANGS
Get PDFFunding: SCOG and RSK acknowledge financial support from the European Research Council via the ERC Synergy Grant “ECOGAL” (project ID 855130), from the German Excellence Strategy via the Heidelberg Cluster of Excellence (EXC 2181 – 390900948) “STRUCTURES”, and from the German Ministry for Economic Affairs and Climate Action in project “MAINN” (funding ID 50OO2206). They are also grateful for computing resources provided by the Ministry of Science, Research and the Arts (MWK) of the State of Baden-Württemberg through bwHPC and the German Science Foundation (DFG) through grants INST 35/1134-1 FUGG and 35/1597-1 FUGG, and also for data storage at SDS@hd funded through grants INST 35/1314-1 FUGG and INST 35/1503-1 FUGG. JG gratefully acknowledges funding via STFC grant ST/Y001133/1. JDH gratefully acknowledges financial support from the Royal Society (University Research Fellowship; URF/R1/221620).New extragalactic measurements of the cloud population-averaged star formation efficiency per free-fall time, ϵff, from PHANGS show little sign of a theoretically predicted dependence on the gas virial level and weak variation with cloud-scale gas velocity dispersion. We explore ways to bring theory into consistency with the observations, particularly by highlighting systematic variations in internal density structure that must accompany an increase in virial parameter typically found toward denser galaxy centers. To introduce these variations into conventional turbulence-regulated star formation models, we adopted three adjustments, all motivated by the expectation that the background host galaxy has an influence on the cloud scale: (1) We incorporate self-gravity and an internal density distribution that contains a broad power-law (PL) component and resembles the structure observed in local resolved clouds; (2) We allow the internal gas kinematics to include motion in the background potential and let this regulate the onset of self-gravitation; (3) We assume that the distribution of gas densities is in a steady state for only a fraction of a cloud free-fall time. In practice, these changes significantly reduce the efficiencies predicted in multi-free-fall (MFF) scenarios compared to purely lognormal probability density functions (PDFs) and tie efficiency variations to variations in the slope of the PL α. We fit the model to PHANGS measurements of ϵff to identify the PL slopes that yield an optimal match. These slopes vary systematically with galactic environment in the sense that gas that sits furthest from virial balance contains fractionally more gas at high density. We relate this to the equilibrium response of gas in the presence of the galactic gravitational potential, which forces more gas to high density than characteristic of fully self-gravitating clouds. Viewing the efficiency variations as originating with time evolution in the PL slope, our findings would alternatively imply coordination of the cloud evolutionary stage within environment. With this “galaxy regulation” behavior included, our preferred “self-gravitating” multi-freefall sgMFF models function similarly to the original, roughly “virialized cloud” single-free-fall models. However, outside the environment of disks with their characteristic regulation, the flexible MFF models may be better suited.Peer reviewe
Many-body open quantum systems
Get PDFFunding: R.F. is supported by the European Research Council via the grant agreements RAVE, 101053159 and the Italian PNRR MUR project PE0000023-NQSTI (R.F.). L.M. acknowledges support from the ANR project LOQUST ANR- 23-CE47-0006-02; this work is also part of HQI (www.hqi.fr) initiative and is supported by France 2030 under the French National Research Agency grant number ANR-22-PNCQ-0002. M.S. acknowledge funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Grant agreement No. 101002955 – CONQUER). This research was supported in part by (i) the International Centre for Theoretical Sciences (ICTS) for R.F. and J.K. participating in the program “Periodically and quasi-periodically driven complex systems” (code: ICTS/pdcs2023/6); and by (ii) the Institut Pascal of Université Paris-Saclay in the framework of the program “Open quantum many-body physics 2023” to which R.F., L.M. and M.S. participated.These lecture notes discuss the recent theoretical advances in the understanding of open quantum many-body physics in platforms where both dissipative and coherent processes can be tuned and controlled to a high degree. We start by reviewing the theoretical frameworks and methods used to describe and tackle open quantum many-body systems. We then discuss the use of dissipative processes to engineer many-body stationary states with desired properties and the emergence of dissipative phase transitions arising out of the competition between coherent evolution and dissipation. We review the dynamics of open quantum many body systems in the presence of correlated many-body dissipative processes, such as heating and many-body losses. Finally we provide a different perspective on open quantum many-body systems by looking at stochastic quantum trajectories, relevant for the case in which the environment represents a monitoring device, and the associated measurement-induced phase transitions.Peer reviewe
Frex: dependently typed algebraic simplification
Get PDFFunding: Supported by the Engineering and Physical Sciences Research Council grant EP/T007265/1 and an Industrial CASE Studentship, a Royal Society University Research Fellowship, a Facebook Research Award, an Alan Turing Institute seed-funding grant, and UK Advanced Research and Innovation Agency (ARIA) as part of the project Qbs4Safety: Core Representation Underlying Safeguarded AI.We present a new design for an algebraic simplification library structured around concepts from universal algebra: theories, models, homomorphisms, and universal properties of free algebras and free extensions of algebras. The library's dependently typed interface guarantees that both built-in and user-defined simplification modules are terminating, sound, and complete with respect to a well-specified class of equations. We have implemented the design in the Idris 2 and Agda dependently typed programming languages and shown that it supports modular extension to new theories, proof extraction and certification, goal extraction via reflection, and interactive development.Peer reviewe
Missing spectral weight in a heavy-fermion system far above Néel temperature
Get PDFFunding: J.L., D.P., C.-J.Y., and M.F. acknowledge the financial support from the Swiss National Science Foundation through Projects No. 200021_178825 and No. 200021_219807. S.P. acknowledges the support from the Department of Atomic Energy (DAE) through the project Basic Research in Physical and Multidisciplinary Sciences via No. RIN4001. S.P. also acknowledges the startup support from DAE through the National Institute of Science Education and Research and the Science and Engineering Research Board (SERB) through a SERB Start-up Research Grant (SRG) via Project No. SRG/2022/000290. U.P. and J.K. acknowledge the support of the Deutsche Forschungsgemeinschaft via TRR 185 (No. 277625399) OSCAR, project C4, and the Cluster of Excellence ML4Q (No. 90534769).The competition between the Kondo spin-screening effect and the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in heavy-fermion systems drives the quantum phase transition (QPT) between the magnetically ordered and the heavy-Fermi-liquid ground states. Despite intensive investigations of heavy quasiparticles on the Kondo-screened side of the QPT and of their breakdown at the quantum critical point, the magnetically ordering side has not systematically been studied. Using terahertz time-domain spectroscopy, we report a suppression of the Kondo quasiparticle weight in CeCu6−Au samples on the antiferromagnetic (AFM) side of the QPT at temperatures as much as two orders of magnitude above the Néel temperature N. With our systematic investigations into the high-temperature, paramagnetic region on the AFM side of the phase diagram of CeCu6−Au, i.e., with = 0.2, 0.3, and 0.5, we show that the suppression results from a quantum frustration effect induced by the temperature-independent RKKY interaction. Hence, our results emphasize that, in addition to critical fluctuations, the RKKY interaction may play an important role in the quantum-critical scenario.Peer reviewe
Developing, evaluating, and interpreting personality state measures : a framework based on the revised latent state-trait theory
Get PDFStates are increasingly important in personality theory and research. Yet, the assessment of personality states usually relies on ad hoc measures whose development and evaluation are largely separated from theoretical considerations. To enable theory-guided development and evaluation of personality state measures, we introduce a framework based on the revised latent state-trait (LST-R) theory. The theory defines latent states as the expectation of an observed measure given a person in a specific situation, which can be decomposed into latent traits and latent situation-specific state residuals. Consequently, items and scales can be evaluated for their reliability due to latent traits (consistency) and situation-specific influences (specificity). We propose that specificity, in particular, is an appealing property for instruments designed to assess personality states. We illustrate this framework with experience sampling data on personality states. Our framework has implications for both the conceptualisation and the assessment of personality states. On the theoretical side, we provide a formal definition of personality states, which enables integration between trait-, process-, and development-focused theories. On the practical side, we show how using LST-R models allows researchers to develop and evaluate state measures on their own terms rather than applying criteria for trait measures to assess the qualities of state measures.Peer reviewe
Double trouble : two transits of the super-Earth GJ 1132 b observed with JWST NIRSpec G395H
Get PDFFunding: R.J.M. is supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51513.001, also awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. The work by S.P. is supported by NASA under award number 80GSFC21M0002. J.K. acknowledges financial support from Imperial College London through an Imperial College Research Fellowship grant. This material is based upon work performed as part of NASA's CHAMPs team, supported by the National Aeronautics and Space Administration (NASA) under grant No. 80NSSC21K0905 issued through the Interdisciplinary Consortia for Astrobiology Research (ICAR) program.The search for rocky planet atmospheres with JWST has focused on planets transiting M dwarfs. Such planets have favorable planet-to-star size ratios, enhancing the amplitude of atmospheric features. Since the expected signal strength of atmospheric features is similar to the single-transit performance of JWST, multiple observations are required to confirm any detection. Here, we present two transit observations of the rocky planet GJ 1132 b with JWST NIRSpec G395H, covering 2.8-5.2 μm. Previous HST WFC3 observations of GJ 1132 b were inconclusive, with evidence reported for either an atmosphere or a featureless spectrum based on analyses of the same dataset. Our JWST data exhibit substantial differences between the two visits. One transit is consistent with either a H2O-dominated atmosphere containing ~1% CH4 and trace N2O (χν2 = 1.13) or stellar contamination from unocculted starspots (χν2 = 1.36). However, the second transit is consistent with a featureless spectrum. Neither visit is consistent with a previous report of HCN. Atmospheric variability is unlikely to explain the scale of the observed differences between the visits. Similarly, our out-of-transit stellar spectra show no evidence of changing stellar inhomogeneity between the two visits - observed 8 days apart, only 6.5% of the stellar rotation rate. We further find no evidence of differing instrumental systematic effects between visits. The most plausible explanation is an unlucky random noise draw leading to two significantly discrepant transmission spectra. Our results highlight the importance of multi-visit repeatability with JWST prior to claiming atmospheric detections for these small, enigmatic planets.Peer reviewe
From the shadows : the impact of nightside thermal emission on ultra-hot Jupiter transmission spectra retrievals
Get PDFFunding: R.J.M. is supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51513.001, awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555.Transmission spectroscopy is the most widely used technique for studying exoplanet atmospheres. Since the planetary nightside faces the observer during a transit, highly irradiated giant exoplanets with warm nightsides emit thermal radiation that can contaminate transmission spectra. Observations of ultrahot Jupiters in the near- and mid-infrared with JWST are especially susceptible to nightside contamination. However, nightside thermal emission is generally not considered in atmospheric retrievals of exoplanet transmission spectra. Here, we quantify the potential biases from neglecting nightside thermal emission in multidimensional atmospheric retrievals of an ultrahot Jupiter. Using simulated JWST transmission spectra of the ultrahot Jupiter WASP-33b (0.8–12 μm), we find that transmission spectrum retrievals without nightside emission can overestimate molecular abundances by almost an order of magnitude and underestimate the dayside temperature by ≳400 K. We show that a modified retrieval prescription, including both transmitted light and nightside thermal emission, correctly recovers the atmospheric properties and is favored by Bayesian model comparisons. Nightside thermal contamination can be readily implemented in retrieval models via a first-order approximation, and we provide formulae to estimate whether this effect is likely to be significant for a given planet. We recommend that nightside emission should be included as standard practice when interpreting ultrahot Jupiter transmission spectra with JWST.Peer reviewe
A retrieval challenge exercise for the Ariel mission
Get PDFFunding: JKB was supported by a Royal Astronomical Society Research Fellowship during this project. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 758892, ExoAI and grant agreement No 776403, ExoplANETS-A) and under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ ERC grant agreement numbers 617119 (ExoLights). Furthermore, we acknowledge funding by the Science and Technology Funding Council (STFC) grants: ST/K502406/1, ST/P000282/1, ST/P002153/1 and ST/S002634/1.The Ariel mission, due to launch in 2029, will obtain spectroscopic information for 1000 exoplanets, providing an unprecedented opportunity for comparative exoplanetology. Retrieval codes - parameteric atmospheric models coupled with an inversion algorithm - represent the tool of choice for interpreting Ariel data. Ensuring that reliable and consistent results can be produced by these tools is a critical preparatory step for the mission. Here, we present the results of a retrieval challenge. We use five different exoplanet retrieval codes to analyse the same synthetic datasets, and test a) the ability of each to recover the correct input solution and b) the consistency of the results. We find that generally there is very good agreement between the five codes, and in the majority of cases the correct solutions are recovered. This demonstrates the reproducibility of retrievals for transit spectra of exoplanets, even when codes are not previously benchmarked against each other.Peer reviewe
Multilingual X/Twitter sentiment analysis of geopolitical risk using Granger causality focusing on the Ukraine war and financial markets
Get PDFFunding: This work was supported by the School of Computer Science of the University of St Andrews.This paper investigates the changes in financial assets and markets from December 1st, 2021, to April 30th, 2022, during the start of the Ukraine War. These dates roughly correspond to the prelude to the War in December 2021 to a few weeks after Russian troops withdrew from the Kyiv area on April 7th, 2022. We used the Goldstein 1992 Results Table to create Positive and Negative Geopolitical Risk bigrams (Goldstein, 1992). With these bigrams, we collected over 3.6 million tweets during our research period in seven different languages (English, Spanish, French, Portuguese, Arabic, Japanese, and Korean) to capture worldwide reaction to the Ukraine War. Using various sentiment analysis methods, we constructed a time series of changes in the daily Geopolitical Risk sentiment. We explored its relationship to 39 financial assets and markets at various time lags. We found through Granger causality that the geopolitical risk time series contained predictive information on several assets and market changes.Peer reviewe
Access Repository Dashboard
Do you manage St Andrews Research Repository? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!