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'Nothing to lose or a world to win' : reconsidering efficacy, legitimacy, political trust and repression in confrontational collective action
No full textConfrontational collective actions are neither uncontrolled outbursts of initially pacifist resistance nor mere reactions to helplessness and lack of viable political options. Instead, they serve strategically determined purposes within the group, making them perceived as both effective and legitimate. Regardless of whether it is more or less confrontational, examining the role of efficacy and legitimacy of actions that are committed to achieving group goals is crucial for understanding the appeal of collective action strategies. We examined the role of political trust and protest repression in predicting the legitimacy of protest violence and the perceived efficacy of confrontational and non-confrontational collective actions and, in turn, their role in confrontational collective action. Across three correlational studies conducted in Germany, Turkey and the United Kingdom (N = 3833), the legitimacy of protest violence and the efficacy of confrontational tactics were core determinants of confrontational collective actions. While low political trust did not directly predict confrontational action, it predicted heightened protest repression and the legitimacy of protest violence. Our findings challenge the nothing-to-lose hypothesis by demonstrating that confrontational actions are not driven by the low efficacy of non-confrontational strategies or low political trust, and people may perceive both confrontational and non-confrontational actions as similarly effective.Peer reviewe
The inside out of journal editing and peer review : a collective reflection on the Review of Education's mentoring scheme for early career researchers
No full textAcademic journals have an ethical obligation to equip and support the next generation of researchers to be active members of academia, including in journal peer review. Although the peer review system is regarded by some as ‘broken’, peer review remains a crucial mechanism for gatekeeping and researcher development. As a group of established and emerging educational researchers, we have benefited from constructive feedback and criticisms from journal editors and peer reviewers. At the same time, we acknowledge that peer review has been one of the sources of frustration for many researchers due to delays, unfavourable outcomes and unhelpful feedback. In this piece, we reflect collectively on our recent experience leading and participating in a mentoring scheme on journal editing and peer review for early career researchers. Our reflections shed light on some hidden aspects of journal editing and peer review, including constraints and challenges faced by editors and peer reviewers. In addition to emphasising the need to empower early career researchers to participate fully in journal peer review through intentional, hands-on and sustained support, we advocate for a compassion-based approach to journal editing and peer review that values empathy, mutual respect and a focus on researchers' emotional well-being.Peer reviewe
Kant's conception of virtue
No full textThis thesis examines Kant’s conception of virtue and the role it plays in his moral theory. In chapter one, I elucidate Kant’s conception of virtue as the strength of our innate capacity to act morally in the face of contrary inclinations. I also show how his other characterisations of virtue as a disposition, as self-constraint, as a free aptitude, and as self-control relate to this central notion of strength. In chapter two, I consider what it means for virtue to be an unattainable ‘ideal’. In calling virtue an ideal, Kant cannot quite mean that moral strength is itself an ideal, for strength is something we can attain, at least to some degree. I show that his claim that virtue is an ideal is instead best understood as an epistemic claim that we cannot and should not assume we have attained ‘perfect’ virtue, or the stability of holiness. I then show that this epistemic claim in fact presupposes his more fundamental claim that it is holiness that is our moral ideal, i.e., the ideal the virtuous person aims at. I also bring out and clarify how dread and cheerfulness, as well as humility and confidence, figure in the life of the virtuous person striving towards this ideal. The final chapter then turns to the question of how we make progress towards holiness. In particular, I highlight and attempt to explain the mysterious role of ‘practice’ in strengthening our capacity for virtue. I argue that practice makes virtue by engendering moral self-respect and confidence in our own improving capacity for virtue. Overall, I explicate Kant’s picture of virtue as endless progress towards holiness. Always rising, yet always fallen, never a God
Hölder continuity of measures for heavy tail potentials
Get PDFFunding: GI was partially supported by Proyecto Fondecyt 1230100. DT would like to thank Henk Bruin for discussions on related topics during the Research-in-Teams project 0223 “Limit Theorems for Parabolic Dynamical Systems” at the Erwin Schrödinger Institute, Vienna. MT would like to thank Pontificia Universidad Católica de Chile where part of this research was done, supported by Proyecto Fondecyt 1230100, and thanks the University of Leiden for hosting a visit where part of this research was done. He is also partially supported by the FCT (Fundação para a Ciência e a Tecnologia) project 2022.07167.PTDC.For a class of potentials ψ satisfying a condition depending on the roof function of a suspension (semi)flow, we show an EKP inequality, which can be interpreted as a Hölder continuity property in the weak∗ norm of measures, with respect to the pressure of those measures, where the Hölder exponent depends on the Lq-space to which ψ belongs. This also captures a new type of phase transition for intermittent (semi)flows (and maps).Peer reviewe
Financial market predictability with artificial intelligence and machine learning techniques
Get PDFThis thesis explores the intersection of financial markets and machine learning, focusing on financial return predictability and the imputation of missing values in financial datasets. The research aims to enhance our understanding of financial market dynamics through the lens of interpretable machine learning models. Specifically, the thesis employs advanced machine learning techniques to predict financial returns and address missing data issues, which are common but often overlooked in financial literature.
The first chapter uses an interpretable machine learning model, LassoNet, to forecast U.S. industry portfolio returns. LassoNet combines a regularization mechanism with a neural network architecture to enforce covariate sparsity. The findings show that LassoNet outperforms linear and non-linear models in forecasting accuracy, with valuation ratios and individual and cross-industry lagged returns being the most critical covariates. The model's forecasts enable the construction of profitable industry ETF portfolios that outperform benchmarks in annualized returns, Sharpe ratios, and alpha values.
The second chapter focuses on imputing missing hedge fund return data using a deep learning model, the bidirectional recurrent imputation network for time series (BRITS). BRITS is compared to other imputation methods like the cross-sectional mean and matrix completion. The results indicate that BRITS significantly enhances forecasting accuracy and economic performance of predictive models when used to impute the missing values in the data. The imputed data leads to lower out-of-sample errors and higher investment returns, demonstrating BRITS' superiority in handling missing values.
In the third chapter, the state-of-the-art neural network architecture TabNet is utilized to forecast the directional movements of excess returns in industry portfolios. TabNet surpasses other models in classification accuracy and highlights the importance of valuation ratios and lagged returns in its predictions. The model effectively captures seasonal effects and cross-industry economic links and attains the highest annualized returns and positive Sharpe ratios in trading applications."This thesis was generously supported by the Clelia Hajiioannou Foundation Scholarship for Postgraduate Studies (academic year 2021-2022), and Sofoklis Achillopoulos Foundation Scholarship for Postgraduate Studies (academic years 2022-2023, and 2023-2024)."--Fundin
Radii, masses, and transit-timing variations of the three-planet system orbiting the naked-eye star TOI-396
Get PDFFunding: This research was funded in part by the UKRI, (Grants ST/X001121/1, EP/X027562/1). P.J.W. acknowledges support from the UK Science and Technology Facilities Council (STFC) through consolidated grants ST/P000495/1, ST/T000406/1 and ST/X001121/1. N.C.S. is funded by the European Union (ERC, FIERCE, 101052347). X.D. acknowledges the support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement SCORE No 851555).Context. TOI-396 is an F6 V bright naked-eye star (V ≈ 6.4) orbited by three small (Rp ≈ 2 R⊕) transiting planets discovered thanks to space-based photometry from two TESS sectors. The orbital periods of the two innermost planets, namely TOI-396 b and c, are close to the 5:3 commensurability (Pb ~ 3.6 d and Pc ~ 6.0 d), suggesting that the planets might be trapped in a mean motion resonance (MMR). Aims. To measure the masses of the three planets, refine their radii, and investigate whether planets b and c are in MMR, we carried out HARPS radial velocity (RV) observations of TOI-396 and retrieved archival high-precision transit photometry from four TESS sectors. Methods. We extracted the RVs via a skew-normal fit onto the HARPS cross-correlation functions and performed a Markov chain Monte Carlo joint analysis of the Doppler measurements and transit photometry, while employing the breakpoint method to remove stellar activity from the RV time series. We also performed a transit timing variation (TTV) dynamical analysis of the system and simulated the temporal evolution of the TTV amplitudes of the three planets following an N-body numerical integration. Results. Our analysis confirms that the three planets have similar sizes (Rb = 2.004−0.047+0.045 R⊕ ; Rc = 1.979−0.051+0.054 R⊕; Rd = 2.001−0.064+0.063 R⊕) and is thus in agreement with previous findings. However, our measurements are ~ 1.4 times more precise thanks to the use of two additional TESS sectors. For the first time, we have determined the RV masses for TOI-396 b and d, finding them to be Mb = 3.55−0.96+0.94 M⊕ and Md = 7.1 ± 1.6 M⊕, which implies bulk densities of ρb = 2.44−0.68+0.69 g cm−3 and ρd = 4.9−1.1+1.2 g cm−3, respectively. Our results suggest a quite unusual system architecture, with the outermost planet being the densest. Based on a frequency analysis of the HARPS activity indicators and TESS light curves, we find the rotation period of the star to be Prot,⋆ = 6.7 ± 1.3 d, in agreement with the value predicted from log R′HK-based empirical relations. The Doppler reflex motion induced by TOI-396 c remains undetected in our RV time series, likely due to the proximity of the planet’s orbital period to the star’s rotation period. We also discovered that TOI-396 b and c display significant TTVs. While the TTV dynamical analysis returns a formally precise mass for TOI-396 c of Mc,dyn = 2.24−0.67+0.13 M⊕, the result might not be accurate, owing to the poor sampling of the TTV phase. We also conclude that TOI-396 b and c are close to but out of the 5:3 MMR. Conclusions. A TTV dynamical analysis of additional transit photometry evenly covering the TTV phase and super-period is likely the most effective approach for precisely and accurately determining the mass of TOI-396 c. Our numerical simulation suggests TTV semi-amplitudes of up to five hours over a temporal baseline of ~ 5.2 years, which should be duly taken into account when scheduling future observations of TOI-396.Peer reviewe
Limited asset market participation and monetary policy in a small open economy
Get PDFLimited asset market participation (LAMP) and trade openness are crucial features that characterize all real-world economies. We study equilibrium determinacy and optimal monetary policy in a model of a small open economy with LAMP. With low enough participation in asset markets, conventional wisdom concerning the stabilizing benefits of policy inertia can be overturned, irrespective of the constraint of a zero lower bound on the nominal interest rate. In contrast to recent studies, trade openness can play an important stabilizing role in LAMP economies. Optimal monetary policy is derived as a robust timeless rule, where the optimal level of interest-rate inertia depends on the degree of trade openness. The optimal rule is shown to be super-inertial for standard economies, whereas the degree of inertia is significantly lower and not super-inertial for LAMP economies.Peer reviewe
Introductionthe 'seven sages of Rome' as a global narrative tradition
No full textThis introduction describes the exceptionally broad multilingual transmission and transcultural significance of ‘The Seven Sages of Rome’ in the mediaeval and early modern Middle East, Europe and Western Asia, also known under names such as ‘Dolopathos’ or ‘The Book / Tales of Sindbad / Sindibad / Syntipas / Sendebar’. We propose to approach this text as a multilingual tradition rather than one separated into different national philologies. The plot reports a non-consensual sexual encounter between a male and a female character, which raises issues of gender and of the wisdom needed to discern the ‘truth’ about this encounter as particularly important topics in the text. We also identify the flexible genre and narrative form of this text, which features multiple embedded narratives within the plot, as research priorities. Several contributions to this special issue have made advances in these areas, but this introduction also aims to identify further research questions that promise to yield additional important results for the premodern and early modern history of gender and literature. Scholars interested in pursuing this research in our emerging ‘Seven Sages’ network are invited to contact the authors.Peer reviewe
The GAPS programme at TNG : XLIX. TOI-5398, the youngest compact multi-planet system composed of an inner sub-Neptune and an outer warm Saturn
Get PDFFunding: Funding for the DPAC has been provided by national institutions, in particular, the institutions participating in the Gaia Multilateral Agreement. This article is based on observations made with the MuSCAT2 instrument, developed by ABC, at Telescopio Carlos Sánchez operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide. This work has been supported by the PRIN-INAF 2019 “Planetary systems at young ages (PLATEA)”. This work is partly financed by the Spanish Ministry of Economics and Competitiveness through grants PGC2018-098153-B-C31. This work is partly supported by JSPS KAKENHI Grant Numbers JP17H04574, JP18H01265, and JP18H05439, Grant-in-Aid for JSPS Fellows Grant Number JP20J21872, JST PRESTO Grant Number JPMJPR1775, and a University Research Support Grant from the National Astronomical Observatory of Japan (NAOJ). This work makes use of observations from the LCOGT network. Part of the LCOGT telescope time was granted by NOIRLab through the MidScale Innovations Program (MSIP). MSIP is funded by NSF. This research has made use of the Exoplanet Follow-up Observation Program (ExoFOP; DOI: 10.26134/ExoFOP5) website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Funding for the TESS mission is provided by NASA’s Science Mission Directorate. K.A.C. and C.N.W. acknowledge support from the TESS mission via subaward s3449 from MIT. T.Zi. acknowledges NVIDIA Academic Hardware Grant Program for the use of the Titan V GPU card. This work is partly supported by JST CREST Grant Number JPMJCR1761. The postdoctoral fellowship of K.B. is funded by F.R.S.-FNRS grant T.0109.20 and by the Francqui Foundation. D.V.C. and I.A.S. acknowledge the support of M.V. Lomonosov Moscow State University Program of Development. R.L. acknowledges funding from University of La Laguna through the Margarita Salas Fellowship from the Spanish Ministry of Universities ref. UNI/551/2021-May 26, and under the EU Next Generation funds. This work is partly supported by the CHEOPS ASI-INAF agreement n. 2019-29-HH.0. G.N. thanks for the research funding from the Ministry of Education and Science programme the “Excellence Initiative – Research University” conducted at the Centre of Excellence in Astrophysics and Astrochemistry of the Nicolaus Copernicus University in Torun, Poland. We acknowledge the use of public TESS data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. A.M., D.L., D.T., and D.P. acknowledge partial financial support from the ARIEL ASI-INAF agreement n.2021-5-HH.0. A.M. also acknowledges “The HOT-ATMOS Project” (PRIN-INAF 2019). D.P. acknowledges the support from the Istituto Nazionale di Oceanografia e Geofisica Sperimentale (OGS) and CINECA through the program “HPC-TRES (High Performance Computing Training and Research for Earth Sciences)” award number 2022-05. P.K. acknowledges the funding from a grant LTT-20015.Context . Short-period giant planets (P ≲ 10 days, Mp >0.1 MJ) are frequently found to be solitary compared to other classes of exo-planets. Small inner companions to giant planets with P ≲ 15 days are known only in five compact systems: WASP-47, Kepler-730, WASP-132, TOI-1130, and TOI-2000. Here, we report the confirmation of TOI-5398, the youngest known compact multi-planet system composed of a hot sub-Neptune (TOI-5398 c, Pc = 4.77271 days) orbiting interior to a short-period Saturn (TOI-5398 b, Pb = 10.590547 days) planet, both transiting around a 650 ± 150 Myr G-type star. Aims : As part of the Global Architecture of Planetary Systems (GAPS) Young Object project, we confirmed and characterised this compact system, measuring the radius and mass of both planets, thus constraining their bulk composition. Methods : Using multi-dimensional Gaussian processes, we simultaneously modelled stellar activity and planetary signals from the Transiting Exoplanet Survey Satellite (TESS) Sector 48 light curve and our High Accuracy Radial velocity Planet Searcher (HARPS-N) radial velocity (RV) time series. We confirmed the planetary nature of both planets, TOI-5398 b and TOI-5398 c, and obtained a precise estimation of their stellar parameters. Results : Through the use of astrometric, photometric, and spectroscopic observations, our findings indicate that TOI-5398 is a young, active G dwarf star (650 ± 150 Myr) with a rotational period of Prot = 7.34 days. The transit photometry and RV measurements enabled us to measure both the radius and mass of planets b, Rb = 10.30 ± 0.40 R⊕, Mb = 58.7 ± 5.7 M⊕, and c, Rc = 3.52 ± 0.19 R⊕, Mc = 11.8 ± 4.8 M⊕. TESS observed TOI-5398 during sector 48 and no further observations are planned in the current Extended Mission, making our ground-based light curves crucial for improvement of the ephemeris. With a transmission spectroscopy metric (TSM) value of around 300, TOI-5398 b is the most amenable warm giant (10 < P < 100 days) for JWST atmospheric characterisation.Peer reviewe
The inflated, eccentric warm Jupiter TOI-4914 b orbiting a metal-poor star, and the hot Jupiters TOI-2714 b and TOI-2981 b
Get PDFFunding: GMa, LBo, TZi, VNa, and GPi acknowledge support from CHEOPS ASI-INAF agreement no. 2019-29-HH.0. TGW would like to acknowledge the University of Warwick and UKSA for their support. The postdoctoral fellowship of KB is funded by F.R.S.-FNRS grant T.0109.20 and by the Francqui Foundation. This publication benefits from the support of the French Community of Belgium in the context of the FRIA Doctoral Grant awarded to MTi. Author F.J.P acknowledges financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/10.13039/501100011033 and Ministerio de Ciencia e Innovación through the project PID2022-137241NB-C43. ACC acknowledges support from STFC consolidated grant number ST/V000861/1, and UKSA grant number ST/X002217/1.Recent observations of giant planets have revealed unexpected bulk densities. Hot Jupiters, in particular, appear larger than expected for their masses compared to planetary evolution models, while warm Jupiters seem denser than expected. These differences are often attributed to the influence of the stellar incident flux, but it has been unclear if they also result from different planet formation processes, and if there is a trend linking the planetary density to the chemical composition of the host star. In this work, we present the confirmation of three giant planets in orbit around solar analogue stars. TOI-2714 b (P ≃ 2.5 d, Rp ≃ 1.22 RJ, Mp = 0.72 MJ) and TOI-2981 b (P ≃ 3.6 d, RP ≃ 1.2 RJ, MP = 2 MJ) are hot Jupiters on nearly circular orbits, while TOI-4914 b (P ≃ 10.6 d, RP ≃ 1.15 RJ, Mp = 0.72 MJ) is a warm Jupiter with a significant eccentricity (e = 0.41 ± 0.02) that orbits a star more metal-poor ([Fe/H] = −0.13) than most of the stars known to host giant planets. Similarly, TOI-2981 b orbits a metal-poor star ([Fe/H] = −0.11), while TOI-2714 b orbits a metal-rich star ([Fe/H] = 0.30). Our radial velocity follow-up with the HARPS spectrograph allows us to detect their Keplerian signals at high significance (7, 30, and 23σ, respectively) and to place a strong constraint on the eccentricity of TOI-4914 b (18σ). TOI-4914 b, with its large radius (Rp ≃ 1.15 RJ) and low insolation flux (F⋆ < 2 × 108 erg s−1 cm−2), appears to be more inflated than what is supported by current theoretical models for giant planets. Moreover, it does not conform to the previously noted trend that warm giant planets orbiting metal-poor stars have low eccentricities. This study thus provides insights into the diverse orbital characteristics and formation processes of giant exoplanets, in particular the role of stellar metallicity in the evolution of planetary systems.Peer reviewe
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