bluuebunny/crossref_metadata_2025_split huggingface dataset:
The population of Galactic supernova remnants in the TeV range
Authors: Batzofin Rowan , Cristofari Pierre , Egberts Kathrin , Steppa Constantin , Meyer Dominique M.-A. 
Published: May 2024

Context.Supernova remnants (SNRs) are likely to be significant sources of cosmic rays up to the knee of the local cosmic-ray (CR) spectrum. They produce gamma rays in the very-high-energy (VHE) (E > 0.1 TeV) range mainly via two mechanisms: hadronic interactions of accelerated protons with the interstellar medium and leptonic interactions of accelerated electrons with soft photons. Observations with current instruments have lead to the detection of about a dozen SNRs emitting VHE gamma rays and future instruments should significantly increase this number. Yet, the details of particle acceleration at SNRs and of the mechanisms producing VHE gamma-rays at SNRs remain poorly understood.Aims.We aim to study the population of SNRs detected in the TeV range and its properties and confront it to simulated samples in order to address fundamental questions concerning particle acceleration at SNR shocks. Such questions concern the spectrum of accelerated particles, the efficiency of particle acceleration, and the gamma-ray emission being dominated by hadronic or leptonic interactions.Methods.By means of Monte Carlo methods, we simulated the population of SNRs in the gamma-ray domain and confronted our simulations to the catalogue of sources from the High Energy Stereoscopic System (H.E.S.S.) Galactic Plane Survey (HGPS).Results.We systematically explored the parameter space defined in our model, including for example, the slope of accelerated particlesα, the electron-to-proton ratioKep, and the efficiency of particle accelerationξ. In particular, we found possible sets of parameters for which ≳90% of Monte Carlo realisations are found to be in agreement with the HGPS. These parameters are typically found at 4.2 ≳ α ≳ 4.1, 10−5 ≲ Kep ≲ 10−4.5, and 0.03 ≲ ξ ≲ 0.1. We are able to strongly argue against some regions of the parameter space describing the population of Galactic SNRs in the TeV range, such asα ≲ 4.05,α ≳ 4.35, orKep ≳ 10−3.Conclusions.Our model is so far able to explain the SNR population of the HGPS. Our approach, when confronted with the results of future systematic surveys, such as the Cherenkov Telescope Array Observatory, will help remove degeneracy from the solutions and to better understand particle acceleration at SNR shocks in the Galaxy.
Dianoga SIDM: Galaxy cluster self-interacting dark matter simulations
Authors: Ragagnin A. , Meneghetti M. , Calura F. , Despali G. , Dolag K. , Fischer M. S. , Giocoli C. , Moscardini L. 
Published: May 2024

Context.Self-interacting dark matter (SIDM) can tackle or alleviate small-scale issues within the cosmological standard model ΛCDM, and diverse flavours of SIDM can produce unique astrophysical predictions, resulting in different possible signatures which can be used to test these models with dedicated observations of galaxy clusters.Aims.This work aims to assess the impact of dark matter self-interactions on the properties of galaxy clusters. In particular, the goal is to study the angular dependence of the cross section by testing rare (large angle scattering) and frequent (small angle scattering) SIDM models with velocity-dependent cross sections.Methods.We re-simulated six galaxy cluster zoom-in initial conditions with a dark matter-only run and with full-physics set-up simulations that include a self-consistent treatment of baryon physics. We tested the dark matter-only setup and the full physics setup with the collisionless cold dark matter, rare self-interacting dark matter, and frequent self-interacting dark matter models. We then studied their matter density profiles as well as their subhalo population.Results.Our dark matter-only SIDM simulations agree with theoretical models, and when baryons are included in simulations, our SIDM models substantially increase the central density of galaxy cluster cores compared to full-physics simulations using collisionless dark matter. SIDM subhalo suppression in full-physics simulations is milder compared to the one found in the dark matter-only simulations because of the cuspier baryonic potential that prevents subhalo disruption. Moreover, SIDM with small-angle scattering significantly suppresses a larger number of subhaloes compared to large-angle scattering SIDM models. Additionally, SIDM models generate a broader range of subhalo concentration values, including a tail of more diffuse subhaloes in the outskirts of galaxy clusters and a population of more compact subhaloes in the cluster cores.
The variation in the response of solar full-disc magnetographs
Authors: Yeo K. L. , Solanki S. K. , Krivova N. A. 
Published: May 2024

Context.The utility of full solar disc magnetograms as a long-term record of the photospheric magnetic field requires an understanding of how stable these observations are with time and the systematic differences between the various instruments.Aims.We compared magnetograms from the KPVT/SPM, SoHO/MDI, SOLIS/VSM, and SDO/HMI with the aim of probing the effect on measured solar magnetism of the variation in instrument response with time, magnetogram signal level, and position on the solar disc.Methods.Taking near-simultaneous observations from the various instruments, we examined the surface coverage by magnetic activity and the effect of cross-calibrating the various instruments under different assumptions.Results.By comparing the surface coverage by magnetic activity in the observations from the various instruments, we traced the effect of the time variation in instrument response on the longitudinal magnetogram signal and disc-integrated unsigned magnetic flux. This yielded evidence of acute changes in the response of MDI and VSM with certain events such as the SoHO vacation in 1998 and the upgrade of the VSM CCD camera in 2009. Excluding these changes, the effect of instrument instability on the magnetogram signal and disc-integrated magnetic flux appears to be rather benign, with an associated uncertainty of less than 2%. We determined the magnetogram signal ratio between each instrument pairing as a function of magnetogram signal level and distance from disc centre and with it cross-calibrated the various instruments. We compared the result with that from repeating the cross-calibration with the overall magnetogram signal ratio. This allowed us to estimate the uncertainty in the magnetogram signal associated with the variation in instrument response with magnetogram signal level and distance from disc centre to be about 8%–14%. The corresponding uncertainty in the disc-integrated magnetic flux is about 7%–23%.Conclusions.To the best of our knowledge, this is the first study of its kind to quantify the uncertainty in measured magnetism from the variation in instrument response with time, magnetogram signal level, and disc position. The results here will be useful to the interpretation of SPM, MDI, VSM, and HMI magnetograms. As examples, we applied our findings to selected results from earlier studies based on such data.
Systematic, noninvasive endometriosis diagnosis in transvaginal sonography by the Swiss Society of Ultrasound in Medicine
Authors: Metzler Julian Matthias , Finger Leana , Burkhardt Tilo , Hodel Markus Eugen , Manegold-Brauer Gwendolin , Imboden Sara , Pape Janna , Imesch Patrick , Witzel Isabell , Bajka Michael 
Published: May 2024

AbstractWe present a new systematic, comprehensive, checklist-based sonographic assessment of endometriosis in the female true pelvis. Emphasis is placed on practical skills teaching. The newly introduced White Sliding Line (WSL) is the core structure. The WSL separates five compartments (anterior, central, posterior, and lateral right and left) containing dedicated endometriosis signs of mobility and morphology to be checked. This approach relies on the 2016 IDEA Consensus and further developments. It directly connects to the 2021 #ENZIAN Classification Standard. In practice, evaluation follows the proposed checklist in all compartments, judging first sliding mobility between organs and structures in a highly dynamic investigation. A rigorous search for deep endometriosis (DE) is then performed. We treat adhesions due to their great clinical importance and possible, reliable diagnosis by TVS as the fifth endometriosis unit, next to endometrioma, DE, adenomyosis, and superficial endometriosis. Including superficial (peritoneal) endometriosis is a future goal.
The Eyelid Trans-orbital Trans-cavernous Approach to the Basilar Apex: A Cadaveric Proof-of-Concept Study
Authors: Zhao Xiaochun , Tan Jeremy , Labib Mohamed A. , Desai Rupen , Graffeo Christopher S. , Bauer Andrew M. , Dunn Ian F. 
Published: May 2024

Abstract
Objective The pretemporal transcavernous approach is an elegant technique that provides exposure to the basilar apex, which is conventionally completed with a frontotemporal incision. This can also be performed via a minimally invasive eyelid transorbital approach, which has unique attributes. This is a proof-of-concept cadaveric study to demonstrate details of the combination of these two approaches.
Design This study is a proof-of-concept study using cadaveric heads.
Setting This study is a proof-of-concept study in a cadaveric laboratory.
Participants A latex-injected cadaveric head.
Main Outcome Measures Detailed dissection was performed and demonstrated in a step-by-step fashion.
Results The eyelid transorbital approach provides the exact exposure required to complete the pretemporal osteotomy including an anterior clinoidectomy and dissection, so that a transcavernous approach can be completed. The basilar apex and its branches can also be accessed via the eyelid transorbital approach, with comparable exposure to the traditional approach; however, the access trajectory is much narrower. It takes advantages of the inferior corridor with a more medial access angle and provides a complementary perspective to the cavernous sinus contents and basilar apex complex.
Conclusion The combination of an eyelid transorbital and pretemporal transcavernous approaches can achieve a deep exposure via a minimally invasive incision, which may add an additional approach to the cavernous sinus and basilar apex regions.
The mixed classroom: a pedagogical experiment with students and policymakers
Authors: Pelzer Peter , Hoffman Jesse , Hajer Maarten A. 
Published: May 2024

AbstractThe societal inability to respond accurately to the ecological crisis also requires a reflection on how universities can improve the impact of their practices. This paper reports on a prize-winning experiment aiming to strengthen the interaction of the university with the world of policymaking: a mixed classroom with students and policymakers. This classroom provides an environment in which policymakers and students co-produce insights, while giving policymakers direct access to academic knowledge and helping students to reflect on the dynamics of real-world contexts. The main goal of this study is to illuminate how learning in and through a mixed classroom experiment take places, for participants, teachers and organisational actors. To do so, we reflect on the continuous dialogue between our efforts as teachers and the experience of participants and others involved. To make sense of our teaching and institutional roles in this experiment, we suggest using the concept of ‘tinkering’. Further, to conceptualise the learning dynamics in a mixed classroom, we deploy the concept of ‘boundary crossing’, which turns out to be helpful in elucidating both individual learning (‘reflection’) and organisational learning (‘transformation’). Our study indicates that the notion of boundary crossing helps to effectively capture the learning situation we created and, as such, helps to redefine more generally how the science-policy interface can be understood and acted upon. For other educators interested in deploying mixed classroom-like approaches, we suggest that a tinkering approach can only work if there is sufficient room for experimentation, including failure and reflection, as well as ample time and funding. We also suggest critically looking at the constraints of the institutional logics and dynamics of higher education (e.g. the structure of semesters) and how their connection to the institutional logics and temporal dynamics of real-world contexts may be improved.
Theory of acoustic polarons in the two-dimensional SSH model applied to the layered superatomic semiconductor Re6Se8Cl2
Authors: Shih Petra , Berkelbach Timothy C. 
Published: May 2024

Layered superatomic semiconductors, whose building blocks are atomically precise molecular clusters, exhibit interesting electronic and vibrational properties. In recent work [Tulyagankhodjaev et al., Science 382, 438 (2023)], transient reflection microscopy revealed quasi-ballistic exciton dynamics in Re6Se8Cl2, which was attributed to the formation of polarons due to coupling with acoustic phonons. Here, we characterize the electronic, excitonic, and phononic properties with periodic density functional theory. We further parameterize a polaron Hamiltonian with nonlocal (Su–Schrieffer–Heeger) coupling to an acoustic phonon to study the polaron ground state binding energy and dispersion relation with variational wavefunctions. We calculate a polaron binding energy of about 10 meV at room temperature, and the maximum group velocity of our polaron dispersion relation is 1.5 km/s, which is similar to the experimentally observed exciton transport velocity.
Conformational and environmental effects on the electronic and vibrational properties of dyes for solar cell devices
Authors: Buttarazzi Edoardo , Inchingolo Antonio , Pedron Danilo , Alberto Marta Erminia , Collini Elisabetta , Petrone Alessio 
Published: May 2024

The main challenge for solar cell devices is harvesting photons beyond the visible by reaching the red-edge (650–780 nm). Dye-sensitized solar cell (DSSC) devices combine the optical absorption and the charge separation processes by the association of a sensitizer as a light-absorbing material (dye molecules, whose absorption can be tuned and designed) with a wide band gap nanostructured semiconductor. Conformational and environmental effects (i.e., solvent, pH) can drastically influence the photophysical properties of molecular dyes. This study proposes a combined experimental and computational approach for the comprehensive investigation of the electronic and vibrational properties of a unique class of organic dye compounds belonging to the family of red-absorbing dyes, known as squaraines. Our focus lies on elucidating the intricate interplay between the molecular structure, vibrational dynamics, and optical properties of squaraines using state-of-the-art density functional theory calculations and spectroscopic techniques. Through systematic vibrational and optical analyses, we show that (i) the main absorption peak in the visible range is influenced by the conformational and protonation equilibria, (ii) the solvent polarity tunes the position of the UV–vis absorption, and (iii) the vibrational spectroscopy techniques (infrared and Raman) can be used as informative tools to distinguish between different conformations and protonation states. This comprehensive understanding offers valuable insights into the design and optimization of squaraine-based DSSCs for enhanced solar energy conversion efficiency.
Dense-sparse quantum Monte Carlo algebraic diagrammatic construction and importance ranking
Authors: Kulahlioglu Adem Halil , Dreuw Andreas 
Published: May 2024

Quantum Monte Carlo Algebraic Diagrammatic Construction (QMCADC) has been proposed as a reformulation of the second-order ADC scheme for the polarization propagator within the projection quantum Monte Carlo formalism. Dense-sparse partitioning and importance ranking filtering strategies are now exploited to accelerate its convergence and to alleviate the sign problem inherent in such calculations. By splitting the configuration space into dense and sparse subsets, the corresponding projection operator is decomposed into four distinct blocks. Deterministic calculations handle the dense-to-dense and sparse-to-dense blocks, while the remaining blocks, dense-to-sparse and sparse-to-sparse, are stochastically evaluated. The dense set is efficiently stored in a fixed-size array, and the sparse set is represented through conventional floating random Monte Carlo walks. The stochastic projection is further refined through importance ranking criteria, enabling a reduction in the required number of walkers with a controllable bias. Our results demonstrate the integration of dense-sparse partitioning with importance ranking filtering to significantly enhance the efficiency of QMCADC, enabling large-scale molecular excited-state calculations. Furthermore, this novel approach maximizes the utilization of the sparsity of ADC(2), transforming QMCADC into a tailored framework for ADC calculations.
The Einstein–Hilbert action for entropically dominant causal sets
Authors: Carlip Peter , Carlip Steve , Surya Sumati 
Published: May 2024

Abstract
In the path integral formulation of causal set quantum gravity, the quantum partition function is a phase-weighted sum over locally finite partially ordered sets, which are viewed as discrete quantum spacetimes. It is known, however, that the number of ‘layered’ sets—a class of causal sets that look nothing like spacetime manifolds—grows superexponentially with the cardinality n, giving an entropic contribution that can potentially dominate that of the action. We show here that in any dimension, the discrete Einstein–Hilbert action for a typical K-layered causal set reduces to the simple link action to leading order in n. Combined with earlier work, this completes the proof that the layered sets, although entropically dominant, are very strongly suppressed in the path sum of causal set quantum gravity whenever the discreteness scale is greater than or equal to a (mildly dimension-dependent) order one multiple of the Planck scale.
Programmable metasurfaces with high angular stability for arbitrarily-polarized obliquely-incident waves
Authors: Xu Liang , Zhang Xin Ge , Li Qi Yang , Jiang Wei Xiang , Cui Tie Jun 
Published: May 2024

Abstract
Programmable metasurfaces show enormous potential in real-time electromagnetic (EM) manipulation and their stable responses to variable EM waves including incident angle and polarization changes are crucial for related applications. However, the demonstrated programmable metasurfaces are commonly considered in normal-incident waves with fixed polarization; how to achieve stable performance in more realistic scenarios of wide-angle and full-polarized wave incidences is still a challenge. Here, we propose and realize a wide-angle and full-polarization programmable metasurface, which can generate stabilized amplitude and phase responses at both transverse electric (TE) and transverse magnetic (TM) oblique incidences. These are achieved by introducing metallic walls around the metasurface element to reduce element coupling, which greatly improves the angular stability of its reflection responses. The mechanisms of angular insensitivity are analyzed comprehensively, and as a proof of concept, obliquely-incident beam steering, large-angle beam scanning and oblique vortex beam emitting are demonstrated on this programmable metasurface. Both the simulation and experimental results demonstrate that the programmable metasurface can operate well at both TE and TM wide-angle oblique incidences in the upper half space. Our work offers an actual route for improving the angular stability and polarization insensitivity of metasurfaces, which could push them one step closer towards more complicated applications.
Janus TiSi

Z

3H (

Z
=

N, P, As) monolayers with large out-of-plane piezoelectricity and high electron mobility: first-principles study
Authors: Vu Tuan V , My Bui Kieu , Hoang Khanh V , Kartamyshev A I , Ho Thi H , Lavrentyev A A , Anh Nguyen P Q , Phuc Huynh V , Hieu Nguyen N 
Published: May 2024

Abstract
In this paper, we propose a series of novel two-dimensional Janus structures TiSiZ
3H (

Z
=

N, P, As) and investigate their electronic, mechanical, piezoelectric, and transport properties using the density functional theory. The examined results demonstrated that Janus TiSiZ
3H monolayers are structurally stable. At the ground state, TiSiN3H, TiSiP3H, and TiSiAs3H monolayers are all semiconductors with indirect bandgaps of 2.98, 1.06, 1.0 eV at the hybrid-functional level, respectively. The absence of vertical mirror symmetry in TiSiZ
3H results in the occurrence of both in-plane and out-of-plane piezoelectricity. Interestingly, TiSiAs3H monolayer exhibits large out-of-plane piezoelectric response with coefficient d
31 up to −0.45 pm V−1, that is appropriate for use in piezoelectric devices. The calculated results demonstrate that the carrier mobility in Janus TiSiZ
3H monolayers is high and directional anisotropic. Particularly, electron mobility in TiSiP3H monolayer is observed up to 772.31 cm2 V−1 s−1. Our results not only suggest and confirm some fundamental physical characteristics of new materials but also lay important premises for experimental studies as well as their application prospects in the future.
Geometrical characterization of healthy red blood cells using digital holographic microscopy and parametric shape models for biophysical studies and diagnostic applications
Authors: Bhabhor Gaurav D , Patel Chetna , Chhillar Nishant , Anand Arun , Lad Kirit N 
Published: May 2024

Abstract
Modeling of the red blood cell (RBC) shape is an integral part of the experimental and computer simulation investigations of light scattering by these cells for fundamental studies as well as diagnostic applications in techniques like cytometry and quantitative phase imaging. In the present work, a comprehensive study of the geometrical characterization of healthy human RBCs using digital holographic microscopy (DHM) and six frequently employed parametric shape models is reported. It is shown that the comparison of the optical phase profiles, and the thickness profiles given by the models with the DHM results gives a better judgment of the appropriateness of the parametric shape models. It is also shown that the RBC parametric models offer a simpler solution to the refractive index-thickness decoupling problem in QPI methods. Results of geometrical characterization of 500 healthy RBCs in terms of volume, surface area (SA), and sphericity index (SI) led to the classification of the parametric models in two categories based on the nature of variation of these quantities with the cell diameter. In light of the variability of the healthy RBC shapes, our findings suggest that the parametric models exhibiting a negative correlation between the SI and the cell diameter would provide more reliable estimates of the RBC parameters in diagnostic applications. Statistical distributions and descriptive statistics of the RBC volume, SA and SI serve as a guide for the assessment of the capability of the studied parametric models to give a reliable account of the variability of the healthy RBC shape and size.