cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: Παραγωγή θειϊκού μαγνησίου από μαγνησιούχα ορυκτά
Creators: name: Ταγριδη Αγγελικη
Publisher: name: Technical University of Crete
Year: 2015

description: Η επιλογή του θέματος της παρούσας μεταπτυχιακής διατριβής, πραγματοποιήθηκε στα πλαίσια της εκμετάλλευσης των απορριμμάτων των εργοστασίων εμπλουτισμού, που περιλαμβάνουν τα μαγνησιούχα ορυκτά, Μαγνησίτη και Σερπεντίνη. Εκμεταλλευόμενοι τα απορρίμματα των μαγνησιούχων ορυκτών, ως πρώτη ύλη, παράγεται θειϊκό μαγνήσιο υπό μορφή ένυδρων κρυστάλλων. Με τις τεχνικές διαλυτοποίησης που εφαρμόζονται επιτυγχάνεται η απευθείας κρυστάλλωση του θειϊκού μαγνησίου, αποφεύγοντας την διαδικασία της εξάτμισης από το διάλυμα που θα χρειαζόταν στην περίπτωση που το Mg παρέμενε σε υγρή μορφή μέσα στο διάλυμα. Συνεπώς επιτυγχάνεται τόσο η μείωση του χρόνου που απαιτείται για την κρυστάλλωση του θειϊκού μαγνησίου από υδατικά διαλύματα, όσο και η  μείωση του κόστους της διαδικασίας.
Pivotal Moments in Student Teaching
Creators: name: Lindhardsen, Vivian
name: Creider, Sarah
Publisher: name: Columbia University
Year: 2019
Subjects: Student teachers
Teacher-student relationships
English language--Study and teaching--Foreign speakers
Student teachers--Evaluation
Teachers--Training of

description: When we first discussed a forum devoted to current and recent student teachers, we simply thought it would be worthwhile to highlight the voices of teachers preparing to work with English Language Learners (ELLs) in our public schools. What we didn’t realize is that we would also hear the voices of their young students—and, in the process, be asked to rethink our own vision of the importance of student teaching.
Studying triangle singularity through spin observables
Creators: name: Wang, Ke
name: Chen, Shao-Fei
name: Liu, Bo-Chao
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: In this work, we study the spin density matrix element $ρ_{00}$ of the $ϕ$ in the decay $J/ψ\rightarrow ηπϕ$. In previous studies, a band around 1.4 GeV on the $π^0ϕ$ distribution in Dalitz plot was reported by the BESIII Collaboration. This structure may be caused by the production of a resonance or the triangle singularity mechanism. We find that the predictions of the spin density matrix elements of the final $ϕ$ based on these mechanisms show distinct features. Thus the measurement of the spin density matrix elements of the $ϕ$ in this reaction may offer an alternative way to study the triangle singularity and to clarify the reaction mechanisms, i.e. resonance production or kinematic effects. This work also shows the potential of spin observables in studying kinematic singularities.
description: 7 pages and 5 figures. Replaced with the published version. Added more calculations and discussions
An alternative power spectrum of the resonance fluorescence of atomic systems
Creators: name: Stokes, Adam
name: Beige, Almut
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We adopt an open quantum systems perspective to calculate the power spectrum associated with the electric field generated by an atomic dipole moment undergoing resonant laser-driving. This spectrum has a similar shape to the usual Mollow spectrum, but also has some distinct features. For sufficiently strong laser driving, both spectra have a symmetric triplet structure with a large central peak and two sidebands. However, the relative height of the sidebands to the central peak differs in each case. The two spectra also behave quite differently when the laser Rabi frequency is varied. Both spectra may be of interest in high-precision experiments into the quantum physics of atomic systems, especially artificial atoms.
description: 9 pages, 3 figures, revised version, details added
Data provenance, curation and quality in metrology
Creators: name: Cheney, James
name: Chapman, Adriane
name: Davidson, Joy
name: Forbes, Alistair
Publisher: name: arXiv
Year: 2021
Subjects: subject: Databases (cs.DB)
subject: FOS: Computer and information sciences

description: Data metrology -- the assessment of the quality of data -- particularly in scientific and industrial settings, has emerged as an important requirement for the UK National Physical Laboratory (NPL) and other national metrology institutes. Data provenance and data curation are key components for emerging understanding of data metrology. However, to date provenance research has had limited visibility to or uptake in metrology. In this work, we summarize a scoping study carried out with NPL staff and industrial participants to understand their current and future needs for provenance, curation and data quality. We then survey provenance technology and standards that are relevant to metrology. We analyse the gaps between requirements and the current state of the art.
Long-Distance Transfer and Routing of Static Magnetic Fields
Creators: name: Navau, Carles
name: Prat-Camps, Jordi
name: Romero-Isart, Oriol
name: Cirac, J. Ignacio
name: Sanchez, Alvaro
Publisher: name: arXiv
Year: 2013
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We show how the static magnetic field of a finite source can be transferred and routed to arbitrary long distances. This is achieved by using transformation optics, which results in a device made of a material with a highly anisotropic magnetic permeability. We show that a simplified version of the device, made by a superconducting-ferromagnet hybrid, also leads to an excellent transfer of the magnetic field. The latter is demonstrated with a proof-of-principle experiment where a ferromagnet tube coated with a superconductor improves the transfer of static magnetic fields with respect to conventional methods by a 400\% factor over distances of 14cm.
description: 5 pages, 5 figures, and Supplementary Material; revised version
The gravity field, orientation, and ephemeris of Mercury from MESSENGER observations after three years in orbit
Creators: name: Mazarico, Erwan
name: Genova, Antonio
name: Goossens, Sander
name: Lemoine, Frank G.
name: Neumann, Gregory A.
name: Zuber, Maria T.
name: Smith, David E.
name: Solomon, Sean C.
Publisher: name: Columbia University
Year: 2014
Subjects: Gravity
Planets--Orbits
Planetary science

description: We have analyzed 3 years of radio tracking data from the MESSENGER spacecraft in orbit around Mercury and determined the gravity field, planetary orientation, and ephemeris of the innermost planet. With improvements in spatial coverage, force modeling, and data weighting, we refined an earlier global gravity field both in quality and resolution, and we present here a spherical harmonic solution to degree and order 50. In this field, termed HgM005, uncertainties in low‐degree coefficients are reduced by an order of magnitude relative to earlier global fields, and we obtained a preliminary value of the tidal Love number k 2 of 0.451 ± 0.014. We also estimated Mercury's pole position, and we obtained an obliquity value of 2.06 ± 0.16 arcmin, in good agreement with analysis of Earth‐based radar observations. From our updated rotation period (58.646146 ± 0.000011 days) and Mercury ephemeris, we verified experimentally the planet's 3:2 spin‐orbit resonance to greater accuracy than previously possible. We present a detailed analysis of the HgM005 covariance matrix, and we describe some near‐circular frozen orbits around Mercury that could be advantageous for future exploration.
title: Collection, unification and presentation of alternative tourism data
title: Συλλογή, ενοποίηση και παρουσίαση δεδομένων εναλλακτικού τουρισμού
Creators: name: Βατικιωτης Ευαγγελος-Αχιλειος
Publisher: name: Technical University of Crete
Year: 2019

description: Ο εναλλακτικός τουρισμός αποτελεί ένα συνεχώς αναπτυσσόμενο ρεύμα στο χώρο του τουρισμού και αναφέρεται στο σύνολο μορφών τουρισμού και δραστηριοτήτων, οι οποίες προσελκύουν ανθρώπους με συγκεκριμένα ενδιαφέροντα. Χαρακτηριστικά παραδείγματα εναλλακτικού τουρισμού αποτελούν ο αγροτουρισμός, ο οικοτουρισμός, ο πολιτιστικός τουρισμός κ.α. Σκοπός της διπλωματικής εργασίας είναι η σχεδίαση και η υλοποίηση μιας διαδικτυακής εφαρμογής, η οποία συλλέγει, διαχειρίζεται και αναπαριστά τοποθεσίες ενδιαφέροντος (Points Of Interest) αθλητικού τουρισμού. Συγκεκριμένα, το σύστημα υποστηρίζει την συλλογή δεδομένων για τοποθεσίες ενδιαφέροντος διαφόρων κατηγοριών μέσω τεχνικών διαδικτυακής εξόρυξης (web scraping), την ενοποίηση τους με την έννοια της κληρονομικότητας καθώς και την αναπαράσταση των τοποθεσιών ενδιαφέροντος μέσω της εφαρμογής. Τέλος, η διαδικτυακή εφαρμογή προσφέρει στους χρήστες την δυνατότητα να εξερευνήσουν νέα σημεία ενδιαφέροντος αθλητικού τουρισμού, καθώς και την δυνατότητα να συμβάλουν στην αξιολόγησή τους.
description: Alternative tourism is a constantly growing trend in the tourism sector and refers to all forms of tourism that attract people with special interests. Typical examples of alternative tourism are agrotourism, ecotourism, cultural tourism and others. The purpose of the diploma thesis is to design and implement a web application that collects, manages and presents Points of Interest related to athletic and active tourism. In particular, the system supports three operations related to athletic or active tourism. Firstly, it supports the collection for points of interest of various categories through web scraping techniques. Secondly it implements their Unification using the concept of inheritance. Last but not least, it presents the Points of Interest and offers to users the opportunity to explore new points of interest in sports tourism, as well as the ability to contribute to their evaluation.
Effects of a global monopole on thermodynamic phase transition of the charged AdS black hole
Creators: name: Luo, Zhi
name: Yu, Hao
name: Li, Jin
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper, we study the dynamical properties of thermodynamic phase transition (PT) for the charged AdS black hole (BH) with a global monopole via the Gibbs free energy landscape and reveal the effects of a global monopole on the kinetics of the AdS BH thermodynamic PT. First, we briefly review the thermodynamics of the charged AdS BH with a global monopole. Then, we introduce the Gibbs free energy landscape to study the thermodynamic stability of the BH state. Because of thermal fluctuations, the small black hole (SBH) state can transit to the large black hole (LBH) state, and vice versa. We use the Fokker-Planck equation with the reflecting boundary condition to study the probability evolution of the BH state with and without a global monopole separately. We find that for both the SBH and LBH states, the global monopole could slow down the evolution of the BH state. In addition, we obtain the relationship between the first passage time and the monopole parameter $η$. The result shows that as the monopole parameter $η$ increases, the mean first passage time will be longer for both the SBH and LBH states.
description: 21 pages, 7 figures, 1 table
Scaling up research data services: a saga of organizational redesign gone awry
Creators: name: Lowry, Linda
Publisher: name: Zenodo
Year: 2021

description: An academic library may initiate organizational renewal and redesign in order to better pursue new strategic priorities. In the case of the Brock University Library, one of these priorities was active engagement throughout the research life cycle. The draft organizational design framework proposed the creation of a new unit that takes a holistic life cycle approach to research, including data literacy, research data management and other services. Unfortunately, it also called for the elimination of the role of subject liaison librarians, who would be redeployed in other ways. No one was more shocked at this turn of events than me, because as the Business and Economics Librarian, I know how crucial it is to understand the disciplinary landscape with respect to research practices in order to develop research data services that align with researcher needs. This study provides evidence for the discipline-specific needs of business and economics researchers for data reference, data literacy, and data retrieval assistance, derived from a content analysis of graduate student theses and a review of consultation statistics. Will this evidence be sufficient to preserve this role, or will this become a saga of organizational redesign gone awry?
On wall crossing for K-stability
Creators: name: Zhou, Chuyu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: In this paper, we explore the wall crossing phenomenon for K-stability, and apply it to explain the wall crossing for K-moduli stacks and K-moduli spaces.
description: Final version. To appear in Advances in Mathematics
อิทธิพลการแพร่กระจายความเย็นของพื้นที่สีเขียวต่อการลดอุณหภูมิในเขตเมืองกรณีศึกษา กรุงเทพมหานคร และจังหวัดนนทบุรี ประเทศไทย
Creators: name: อดุลย์เดช ปัดภัย
Publisher: name: สถาบันวิจัยและพัฒนา มหาวิทยาลัยเทคโนโลยีราชมงคลธัญบุรี
Year: 2023
Subjects: Land surface temperature
Heat island
Normalized difference vegetation index
Cooling intensity
Green area

description: Journal of Applied Research on Science and Technology (JARST), 22, 1, 104-116
Goal-Oriented Adaptive Finite Element Multilevel Monte Carlo with Convergence Rates
Creators: name: Beck, Joakim
name: Liu, Yang
name: von Schwerin, Erik
name: Tempone, Raúl
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65C05, 65N50, 65N22, 35R60

description: We present an adaptive multilevel Monte Carlo (AMLMC) algorithm for approximating deterministic, real-valued, bounded linear functionals that depend on the solution of a linear elliptic PDE with a lognormal diffusivity coefficient and geometric singularities in bounded domains of $\mathbb{R}^d$. Our AMLMC algorithm is built on the results of the weak convergence rates in the work [Moon et al., BIT Numer. Math., 46 (2006), 367-407] for an adaptive algorithm using isoparametric d-linear quadrilateral finite element approximations and the dual weighted residual error representation in a deterministic setting. Designed to suit the geometric nature of the singularities in the solution, our AMLMC algorithm uses a sequence of deterministic, non-uniform auxiliary meshes as a building block. The deterministic adaptive algorithm generates these meshes, corresponding to a geometrically decreasing sequence of tolerances. For a given realization of the diffusivity coefficient and accuracy level, AMLMC constructs its approximate sample using the first mesh in the hierarchy that satisfies the corresponding bias accuracy constraint. This adaptive approach is particularly useful for the lognormal case treated here, which lacks uniform coercivity and thus produces functional outputs that vary over orders of magnitude when sampled. We discuss iterative solvers and compare their efficiency with direct ones. To reduce computational work, we propose a stopping criterion for the iterative solver with respect to the quantity of interest, the realization of the diffusivity coefficient, and the desired level of AMLMC approximation. From the numerical experiments, based on a Fourier expansion of the coefficient field, we observe improvements in efficiency compared with both standard Monte Carlo and standard MLMC for a problem with a singularity similar to that at the tip of a slit modeling a crack.
description: Fixed typos, included more proofs and discussions
Controlling single-photon transport in waveguides with finite cross-section
Creators: name: Huang, Jin-Feng
name: Shi, Tao
name: Sun, C. P.
name: Nori, Franco
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the transverse-size effect of a quasi-one-dimensional rectangular waveguide on the single-photon scattering on a two-level system. We calculate the transmission and reflection coefficients for single incident photons using the scattering formalism based on the Lippmann-Schwinger equation. When the transverse size of the waveguide is larger than a critical size, we find that the transverse mode will be involved in the single-photon scattering. Including the coupling to a higher traverse mode, we find that the photon in the lowest channel will be lost into the other channel, corresponding to the other transverse modes, when the input energy is larger than the maximum bound-state energy. Three kinds of resonance phenomena are predicted: single-photon resonance, photonic Feshbach resonance, and cutoff (minimum) frequency resonance. At these resonances, the input photon is completely reflected.
description: 9 pages, 6 figures
Cascade of transitions in twisted and non-twisted graphene layers within the van Hove scenario
Creators: name: Chichinadze, Dmitry V.
name: Classen, Laura
name: Wang, Yuxuan
name: Chubukov, Andrey V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Motivated by measurements of compressibility and STM spectra in twisted bilayer graphene, we analyze the pattern of symmetry breaking for itinerant fermions near a van Hove singularity. Making use of an approximate SU(4) symmetry of the Landau functional, we show that the structure of the spin/isospin order parameter changes with increasing filling via a cascade of transitions. We compute the feedback from different spin/isospin orders on fermions and argue that each order splits the initially 4-fold degenerate van Hove peak in a particular fashion, consistent with the STM data and compressibility measurements, providing a unified interpretation of the cascade of transitions in twisted bilayer graphene. Our results follow from a generic analysis of an SU(4)-symmetric Landau functional and are valid beyond a specific underlying fermionic model. We argue that an analogous van Hove scenario explains the cascade of phase transitions in non-twisted Bernal bilayer and rhombohedral trilayer graphene.
description: Final version accepted by npj Quantum Materials; 47 pages in preprint format (main text + SM), 3+8 figures
title: MIMO capacity estimation using MIMObit
title: Εκτίμηση χωρητικότητας συστημάτων MIMO με χρήση του MIMObit
Creators: name: Σγουρακης Ανδρεας
Publisher: name: Technical University of Crete
Year: 2019

description: Σε αυτήν την εργασία, μελετάμε την απόδοση ασύρματων συστημάτων πολλαπλών εισόδων πολλαπλών εξόδων. Συγκεκριμένα, εξετάζουμε τη χωρητικότητα για διαφορετικά σενάρια συστημάτων και με διαφορετικά μοντέλα διάδοσης. Τα συστήματα ΜΙΜΟ που αναλύονται περιλάμβάνουν την περίπτωση με ένα χρήστη όπου χρησιμοποιούνται πολλαπλές κεραίες και την περίπτωση πολλαπλών χρηστών με δύο χρήστες και μία κεραία σε καθένα από αυτούς και το σταθμό βάσης. Εξετάζουμε τις ιδιότητες της χωρητικότητας στην περίπτωση άγνωστου και γνωστού καναλιού διάδοσης. Στην περίπτωση όπου το τελευταίο είναι ανέφικτο, παρουσιάζουμε τρόπους να εκτιμήσουμε την βέλτιστη κατανομή ισχύος και να προσεγγίσουμε τη χωρητικότητα του συστήματος. Για να προσομοιώσουμε συστήματα επικοινωνίας κάτω από διαφορετικά περιβάλλοντα μετάδοσης, χρησιμοποιούμε το MIMObit της Nebens το οποίο παρέχει μία ολοκληρωμένη πλατφόρμα η οποία λαμβάνει υπ’ όψη της τις κεραίες που χρησιμοποιούνται στο πομπό και στο δέκτη. Εξετάζουμε την ακρίβεια αποτελεσμάτων προσομοίωσης που παρέχονται από το MIMObit χρησιμοποιώντας διπολικές κεραίες που δημιουργήθηκαν στο γραφικό του περιβάλλον και στο CST Microwave Studio. Τέλος, κάνουμε κάποιες συγκρίσεις εκτίμησης χωρητικότητας χρησιμοποιώντας τα κανάλια που παράγονται από το MIMObit και το Matlab.
description: In this work, we study the performance of multiple-input multiple-output (MIMO) wireless systems. Specifically, we examine their capacity for
different system scenaria and with different propagation models. The MIMO systems analyzed include the single-user case where multiple
antennas are used and the multiuser case with two users present and a single antenna at each of them and the base station. We examine the capacity properties in the case of unknown and known propagation channel. In the case where the latter is infeasible, we present ways to estimate the optimal power allocation and approach the system capacity.
To simulate communication systems under various propagation environments, we use Neben's MIMObit which offers an integrated platform
that fully takes into account the antennas used at the transmitter and the receiver. We evaluate the accuracy of simulation results provided by MIMObit using dipole antennas created in its graphical user interface and in CST Microwave Studio. Finally, we make some capacity estimation comparisons using the channels produced by MIMObit and Matlab.​
A strictly stationary $β$-mixing process satisfying the central limit theorem but not the weak invariance principle
Creators: name: Giraudo, Davide
name: Volny, Dalibor
Publisher: name: arXiv
Year: 2013
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60F05, 60F17

description: In 1983, N. Herrndorf proved that for a $ϕ$-mixing sequence satisfying the central limit theorem and $\liminf_{n\to\infty}\frac{σ^2_n}n>0$, the weak invariance principle takes place. The question whether for strictly stationary sequences with finite second moments and a weaker type ($α$, $β$, $ρ$) of mixing the central limit theorem implies the weak invariance principle remained open. We construct a strictly stationary $β$-mixing sequence with finite moments of any order and linear variance for which the central limit theorem takes place but not the weak invariance principle.
description: 12 pages
Von Romulus zu Augustus. Große Gestalten der römischen Republik
Creators: name: Lobe, Michael
Publisher: name: Forum Classicum
Year: 2017

description: Rezension zu: Von Romulus zu Augustus. Große Gestalten der römischen Republik. Hrsg. v. K.-J. Hölkeskamp u. E. Stein-Hölkeskamp. München: Beck 2000. 394 S. (ISBN 3-406-46697-4).
description: Forum Classicum, Nr. 1 (2001): Forum Classicum
Bayesian Physics-Informed Neural Networks for real-world nonlinear dynamical systems
Creators: name: Linka, Kevin
name: Schafer, Amelie
name: Meng, Xuhui
name: Zou, Zongren
name: Karniadakis, George Em
name: Kuhl, Ellen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Dynamical Systems (math.DS)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: G.3; J.3
subject: 62Mxx, 70Kxx

description: Understanding real-world dynamical phenomena remains a challenging task. Across various scientific disciplines, machine learning has advanced as the go-to technology to analyze nonlinear dynamical systems, identify patterns in big data, and make decision around them. Neural networks are now consistently used as universal function approximators for data with underlying mechanisms that are incompletely understood or exceedingly complex. However, neural networks alone ignore the fundamental laws of physics and often fail to make plausible predictions. Here we integrate data, physics, and uncertainties by combining neural networks, physics-informed modeling, and Bayesian inference to improve the predictive potential of traditional neural network models. We embed the physical model of a damped harmonic oscillator into a fully-connected feed-forward neural network to explore a simple and illustrative model system, the outbreak dynamics of COVID-19. Our Physics-Informed Neural Networks can seamlessly integrate data and physics, robustly solve forward and inverse problems, and perform well for both interpolation and extrapolation, even for a small amount of noisy and incomplete data. At only minor additional cost, they can self-adaptively learn the weighting between data and physics. Combined with Bayesian Neural Networks, they can serve as priors in a Bayesian Inference, and provide credible intervals for uncertainty quantification. Our study reveals the inherent advantages and disadvantages of Neural Networks, Bayesian Inference, and a combination of both and provides valuable guidelines for model selection. While we have only demonstrated these approaches for the simple model problem of a seasonal endemic infectious disease, we anticipate that the underlying concepts and trends generalize to more complex disease conditions and, more broadly, to a wide variety of nonlinear dynamical systems.
On the strong coupling problem in cosmologies with "strong gravity in the past"
Creators: name: Ageeva, Y.
name: Petrov, P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We examine the potential strong coupling problem at early times in a bouncing cosmological model with "strong gravity in the past" (Jordan frame), which is conformally related to inflation (Einstein frame). From naive dimensional analysis in the Jordan frame one would conclude that the quantum strong coupling energy scale can be lower than the classical energy scale. However, from the Einstein frame prospective this should not be the case. We illustrate this point by calculation in the Jordan frame which shows cancellations of the dangerous contributions in the tree level amplitude.
description: 9 pages
The Chaplygin Gas Equation of State for the Quantized Free Scalar Field on Cosmological Spacetimes
Creators: name: Zschoche, Jan
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We try to answer the question whether the quantized free scalar field on a spatially flat Friedmann-Robertson-Walker (FRW) spacetime is a matter model that can induce a Chaplygin gas equation of state. For this purpose we first describe how one can obtain every possible homogeneous and isotropic Hadamard (HIH) state once any such state is given. We also identify a condition on the scale factor sufficient to entail the existence of a simple HIH state $-$ this state is constructed explicitly and can thence be used as a starting point for constructing all HIH states. Furthermore, we employ these results to show that on an FRW spacetime with non-positive constant scalar curvature there is, with one exception, no Chaplygin gas equation of state compatible with any HIH state. Finally, we argue that the semi-classical Einstein equation and the Chaplygin gas equation of state can presumably not be consistently solved for the quantized free scalar field.
description: 33 pages; paper shortened, comments added
A step in the right direction? Analyzing the Wess Zumino Dark Radiation solution to the Hubble tension
Creators: name: Schöneberg, Nils
name: Abellán, Guillermo Franco
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The Wess Zumino Dark Radiation (WZDR) model first proposed in arXiv:2111.00014 shows great promise as a well-motivated simple explanation of the Hubble tension between local and CMB-based measurements. In this work we investigate the assumptions made in the original proposal and confront the model with additional independent data sets. We show that the original assumptions can have an impact on the overall results but are usually well motivated. We further demonstrate that the preference for negative $Ω_k$ remains at a similar level as for the $Λ$CDM model, while the $A_L$ tension is slightly increased. Furthermore, the tension between Planck data for $\ell < 800$ and $\ell \geq 800$ is significantly reduced for the WZDR model. The independent data sets show slightly more permissive bounds on the Hubble parameter, allowing the tension to be further reduced to $2.1 σ$ (CMB-independent) or $1.9σ$ (ACT+WMAP). However, no combination shows a large preference for the presence of WZDR. We also investigate whether additional dark radiation -- dark matter interactions can help in easing the $S_8$ tension as well. Assuming all of the dark matter to be interacting and a temperature-independent scattering rate, we find that the CMB data are too restrictive on this additional component as to allow a significant decrease in the clustering.
description: 25 pages, 10 figures, 2 tables. Any comments and suggestions are welcome! Edit: Citations, update of A_L tension results, and comment relating to S_8 tension
Breidecker, Volker: Rom. Ein kulturgeschichtlicher Reiseführer / Waiblinger, Franz Peter: Rom. Ein literarischer Reiseführer
Creators: name: Lobe, Michael
Publisher: name: Forum Classicum
Year: 2017

description: Rezension zu:

Breidecker, Volker: Rom. Ein kulturgeschichtlicher Reiseführer. Stuttgart: Reclam 2000. 326 S. (ISBN 3-15-010466-1).

Waiblinger, Franz Peter: Rom. Ein literarischer Reiseführer. Darmstadt: Wiss. Buchges. 2000. 290 S. (ISBN 3-534-14994-7).
description: Forum Classicum, Nr. 1 (2001): Forum Classicum
Features of the Primordial Universe in f(R)-gravity as viewed in the Jordan frame
Creators: name: Bamonti, Nicola
name: Costantini, Andrea
name: Montani, Giovanni
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We analyze some relevant features of the primordial Universe as viewed in the Jordan frame formulation of the f(R)-gravity, especially when the potential term of the non-minimally coupled scalar field is negligible. We start formulating the Hamiltonian picture in the Jordan frame, using the 3-metric determinant as a basic variable and we outline that its conjugated momentum appears linearly only in the scalar constraint. Then, we construct the basic formalism to characterize the dynamics of a generic inhomogeneous cosmological model and specialize it in order to describe behaviors of the Bianchi Universes, both on a classical and a quantum regime. As a fundamental issue, we demonstrate that, when the potential term of the additional scalar mode is negligible near enough to the initial singularity, the Bianchi IX cosmology is no longer affected by the chaotic behavior, typical in vacuum of the standard Einsteinian dynamics. In fact, the presence of stable Kasner stability region and its actractive character are properly characterized. Finally, we investigate the canonical quantization of the Bianchi I model, using as time variable the non-minimally coupled scalar field and showing that the existence of a conserved current is outlined for the corresponding Wheeler-DeWitt equation. The behavior of a localized wave-packet for the isotropic Universe is also evolved, demonstrating that the singularity is still present in this revised quantum dynamics.
description: 20 pages, 8 figures
Support of long‐wavelength topography on Mercury inferred from MESSENGER measurements of gravity and topography
Creators: name: James, Peter B.
name: Zuber, Maria T.
name: Phillips, Roger J.
name: Solomon, Sean C.
Publisher: name: Columbia University
Year: 2015
Subjects: Planets--Surfaces
Topographic maps
Gravity

description: To explore the mechanisms of support of surface topography on Mercury, we have determined the admittances and correlations of topography and gravity in Mercury's northern hemisphere from measurements obtained by NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. These admittances and correlations can be interpreted in the context of a number of theoretical scenarios, including flexural loading and dynamic flow. We find that long‐wavelength (spherical harmonic degree l
3D Yang-Mills Glueballs vs Closed Effective Strings
Creators: name: Dubovsky, Sergei
name: Hernández-Chifflet, Guzmán
name: Zare, Shahrzad
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: Recent lattice results strongly support the Axionic String Ansatz (ASA) for quantum numbers of glueballs in 3D Yang-Mills theory. The ASA treats glueballs as closed bosonic strings. The corresponding worldsheet theory is a deformation of the minimal Nambu-Goto theory. In order to understand better the ASA strings and as a first step towards a perturbative calculation of the glueball mass splittings we compare the ASA spectrum to the closed effective string theory. Namely, we model glueballs as excitations around the folded rotating rod solution with a large angular momentum $J$. The resulting spectrum agrees with the ASA in the regime of validity of the effective theory, i.e., in the vicinity of the leading Regge trajectory. In particular, closed effective string theory correctly predicts that only glueballs of even spin $J$ show up at the leading Regge trajectory. Interestingly though, the closed effective string theory overestimates the number of glueball states far above the leading Regge trajectory.
description: 25 pages, 4 figures, some typos corrected
Systematic KMTNet Planetary Anomaly Search. VI. Complete Sample of 2018 Sub-Prime-Field Planets
Creators: name: Jung, Youn Kil
name: Zang, Weicheng
name: Han, Cheongho
name: Gould, Andrew
name: Udalski, Andrzej
name: Albrow, Michael D.
name: Chung, Sun-Ju
name: Hwang, Kyu-Ha
name: Ryu, Yoon-Hyun
name: Shin, In-Gu
name: Shvartzvald, Yossi
name: Yang, Hongjing
name: Yee, Jennifer C.
name: Cha, Sang-Mok
name: Kim, Dong-Jin
name: Kim, Seung-Lee
name: Lee, Chung-Uk
name: Lee, Dong-Joo
name: Lee, Yongseok
name: Park, Byeong-Gon
name: Pogge, Richard W.
name: Mróz, Przemek
name: Szymański, Michał K.
name: Skowron, Jan
name: Poleski, Radek
name: Soszyński, Igor
name: Pietrukowicz, Paweł
name: Kozłowski, Szymon
name: Ulaczyk, Krzysztof
name: Rybicki, Krzysztof A.
name: Iwanek, Patryk
name: Wrona, Marcin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We complete the analysis of all 2018 sub-prime-field microlensing planets identified by the KMTNet AnomalyFinder. Among the 9 previously unpublished events with clear planetary solutions, 6 are clearly planetary (KMT-2018-BLG-0030, KMT-2018-BLG-0087, KMT-2018-BLG-0247, OGLE-2018-BLG-0298, KMT-2018-BLG-2602, and OGLE-2018-BLG-1119), while the remaining 3 are ambiguous in nature. In addition, there are 8 previously published sub-prime field planets that were selected by the AnomalyFinder algorithm. Together with a companion paper (Gould et al. 2022) on 2018 prime-field planets, this work lays the basis for the first statistical analysis of the planet mass-ratio function based on planets identified in KMTNet data. As expected (Zhu et al. 2014), half (17/33) of the 2018 planets likely to enter the mass-ratio analysis have non-caustic-crossing anomalies. However, only 1 of the 5 non-caustic anomalies with planet-host mass ratio $q<10^{-3}$ was discovered by eye (compared to 7 of the 12 with $q>10^{-3}$), showing the importance of the semi-automated AnomalyFinder search.
description: 56 pages, 13 tables, 14 figures, submitted to AAS Journals
Score-based Generative Models for Calorimeter Shower Simulation
Creators: name: Mikuni, Vinicius
name: Nachman, Benjamin
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Machine Learning (cs.LG)
subject: High Energy Physics - Experiment (hep-ex)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Score-based generative models are a new class of generative algorithms that have been shown to produce realistic images even in high dimensional spaces, currently surpassing other state-of-the-art models for different benchmark categories and applications. In this work we introduce CaloScore, a score-based generative model for collider physics applied to calorimeter shower generation. Three different diffusion models are investigated using the Fast Calorimeter Simulation Challenge 2022 dataset. CaloScore is the first application of a score-based generative model in collider physics and is able to produce high-fidelity calorimeter images for all datasets, providing an alternative paradigm for calorimeter shower simulation.
title: Νέα διαμόρφωση της πλατείας Τάλω και συμπληρωματικές κτηριακές εγκαταστάσεις
στα Χανιά
title: Re-imagining Talo Square and additional building facilities in Chania
Creators: name: Γιοβανογλου Ρωξανη
Publisher: name: Technical University of Crete
Year: 2019

description: Η παρούσα διπλωματική εργασία αποτελεί πρόταση ανάπλασης του βορειοδυτικού παραλιακού μετώπου των Χανίων, που βρίσκεται στη συνέχεια του Ενετικού λιμανιού, με σκοπό την ενεργοποίηση της περιοχής μελέτης, τη σύνδεση της με την παλιά πόλη και την περιοχή της Νέας Χώρας και την συμπλήρωση -ανάδειξη του μνημειακού συγκροτήματος των τειχών.
Πρόθεσή είναι ο σχεδιασμός να συμπληρώσει το αστικό τοπίο και να δημιουργήσει μια συμβολική συνέχεια με αυτό, να επαναπροσδιορίσει τη σχέση της περιοχής με τη θάλασσα και να δημιουργήσει μια σειρά δημόσιων χώρων, οι οποίοι θα τροφοδοτήσουν τη νέα κατάσταση. Λαμβάνοντας υπόψιν την πολιτισμική σημαντικότητα της περιοχής και του όγκου των επισκεπτών στο ιστορικό κομμάτι της πόλης, επιλέγεται τόσο η ανάπτυξη δραστηριοτήτων πολιτισμικού χαρακτήρα, όσο και η απόδοση τουριστικών χρήσεων για τους επισκέπτες της. Πιο συγκεκριμένα, η μελέτη περιλαμβάνει την διαμόρφωση της ευρύτερης περιοχής της πλατείας Τάλω και του προμαχώνα San Salvatore, τον σχεδιασμό ενός κέντρου ενημέρωσης επισκεπτών, στο χώρο που βρίσκεται σήμερα η εξωτερική εγκατάσταση λουομένων του ξενοδοχείου Ξενία, και τη δημιουργία ενός θεατρικού εργαστηρίου στη συνέχεια των τειχών.
Squeezed Thermal State Representation of the Inflaton and Particle Production in Bianchi type-I Universe
Creators: name: Chand, Karam
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: In this study, we use a single-mode squeezed thermal vacuum state formalism and examine the nature of a massive homogeneous scalar field, minimally coupled to the gravity in the framework of semiclassical gravity in the Bianchi type-I universe. We have obtained an estimate leading solution to the semiclassical Einstein equation for the Bianchi type-I universe shows, each scale factor in its respective direction obeys t^(2/3) power-law expansion. The mechanism of the nonclassical thermal cosmological particle production is also analyzed in the Bianchi type-I universe.
title: Προγενέθλια μνήμη στους Barozzi-Veiga
Creators: name: Γιοβανογλου Ρωξανη
Publisher: name: Technical University of Crete
Year: 2018

description: Η παρούσα μελέτη διερευνά την έννοια του τόπου στο έργο του  αρχιτεκτονικού γραφείου Barozzi-Veiga, σε σχέση με τον τρόπο που προσεγγίστηκε η ίδια έννοια από την σχολή της Tendenza. Προκειμένου να οριστεί το  πλαίσιο διερεύνησης της μελέτης, γίνεται αρχικά μια σύντομη αναφορά στην έννοια του τόπου, όπως προσεγγίστηκε από τους αρχιτέκτονες του ιταλικού ρασιοναλισμού. Έπειτα αναλύεται το ιταλικό νεορασιοναλιστικό κίνημα και παρουσιάζονται οι θέσεις τριών αρχιτεκτόνων, οι φυσιογνωμίες των οποίων άσκησαν την μεγαλύτερη επιρροή τη δεκαετία του ‘60. Στη συνέχεια  γίνεται εισαγωγή στο έργο των Barozzi-Veiga, από τις σκέψεις και τις προθέσεις τους, στο σχεδιασμό και την υλοποίηση. Αναλύεται ο τρόπος με τον οποίο αντιλαμβάνονται την έννοια του τόπου και ο τρόπος που περιλαμβάνουν τη μνήμη και την ιστορία του τόπου στη σχεδιαστική τους διαδικασία. Τέλος, πραγματοποιείται η μετάβαση στο υλοποιημένο έργο του γραφείου, όπου αναλύονται τρία έργα τους. Επομένως, το ζήτημα που προκύπτει είναι πώς οι αρχιτεκτονικές κατασκευές αφομοιώνουν την  ιδιαιτερότητα του τόπου, ερμηνεύουν την παράδοση και ενισχύουν τη συλλογική μνήμη, ενώ παράλληλα διατηρούν την αυτονομίας της μορφής τους.
Algebraic semantics for a modal logic close to S1
Creators: name: Lewitzka, Steffen
Publisher: name: arXiv
Year: 2013
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences
subject: 03B45

description: The modal systems S1--S3 were introduced by C. I. Lewis as logics for strict implication. While there are Kripke semantics for S2 and S3, there is no known natural semantics for S1. We extend S1 by a Substitution Principle SP which generalizes a reference rule of S1. In system S1+SP, the relation of strict equivalence $φ\equivψ$ satisfies the identity axioms of R. Suszko's non-Fregean logic adapted to the language of modal logic (we call these axioms the axioms of propositional identity). This enables us to develop a framework of algebraic semantics which captures S1+SP as well as the Lewis systems S3--S5. So from the viewpoint of algebraic semantics, S1+SP turns out to be an interesting modal logic. We show that S1+SP is strictly contained between S1 and S3 and differs from S2. It is the weakest modal logic containing S1 such that strict equivalence is axiomatized by propositional identity.
description: 14 pages, thoroughly revised and extended version, title has changed
Images and photon ring signatures of thick disks around black holes
Creators: name: Vincent, Frederic H.
name: Gralla, Samuel E.
name: Lupsasca, Alexandru
name: Wielgus, Maciek
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: High-frequency very-long-baseline interferometry (VLBI) observations can now resolve the horizon-scale emission from sources in the immediate vicinity of nearby supermassive black holes. Future space-VLBI observations will access highly lensed features of black hole images -- photon rings -- that will provide particularly sharp probes of strong-field gravity. Focusing on the particular case of the supermassive black hole M87*, our goal is to explore a wide variety of accretion flows onto a Kerr black hole and to understand their corresponding images and visibilities. We are particularly interested in the visibility on baselines to space, which encodes the photon ring shape and whose measurement could provide a stringent test of the Kerr hypothesis. We develop a fully analytical model of stationary, axisymmetric accretion flows with a variable disk thickness and a matter four-velocity that can smoothly interpolate between purely azimuthal rotation and purely radial infall. We then determine the observational appearance of such flows, taking care to include the effects of thermal synchrotron emission and absorption. Our images generically display a "wedding cake" structure composed of discrete, narrow photon rings (n=1,2,...) stacked on top of broader primary emission that surrounds a central brightness depression of model-dependent size. We find that the "black hole shadow" is a model-dependent phenomenon -- even for diffuse, optically thin sources -- and should not be regarded as a generic prediction of general relativity. At 230 GHz, the n=1 ring is always visible, but the n=2 ring is sometimes suppressed due to absorption. At 345 GHz, the medium is optically thinner and the n=2 ring displays clear signatures in both the image and visibility domains, identifying this frequency as more promising for future space-VLBI measurements of the photon ring shape.
description: 21 pages, 9 figure, accepted by A&A, minor changes
title: Θρησκευτικό Forum στο Λιμάνι Θεσσαλονίκης. Μία αντικειμενοστραφής προσέγγιση του χώρου λατρείας στη σύγχρονη πόλη
title: Religious Forum in the Port of Thessaloniki. An object-oriented approach to the place of worship in the modern city
Creators: name: Παπαδοπουλος Τριανταφυλλος
Publisher: name: Technical University of Crete
Year: 2019

description: Στόχος της συγκεκριμένης διπλωματικής εργασίας είναι ο σχεδιασμός ενός θρησκευτικού φόρουμ, ενός χώρου μέσα στον οποίο να επιτρέπεται η λατρεία και η άσκηση οποιασδήποτε θρησκείας, ανεξαρτήτως πολιτιστικών διαφοροποιήσεων. Αφορμή σύλληψης της συγκεκριμένης ιδέας αποτέλεσε η παρατήρηση έλλειψης χώρων θρησκευτικής συνομιλίας μεταξύ των χρηστών του αστικού συνόλου. Επιλέγεται ο όρος Forum και όχι εκκλησία, καθώς επιδιώκεται η σχεδίαση ενός συνόλου λειτουργικά ελαστικού, στο οποίο μέλη οποιασδήποτε λατρείας μπορούν να ασκήσουν και να επικοινωνήσουν τις ιδέες τους μέσα σε ένα περιβάλλον που να προωθεί τον ειρηνικό ιδεολογικό διάλογο. Παράλληλα, ένα τέτοιο περιβάλλον φαίνεται να έχει ανάγκη μία άμεση και οργανική σύνδεση με το ευρύτερο αστικό σύνολο και ιστό της πόλης, στο οποίο υπάγεται και εξυπηρετεί. Για το λόγο αυτό, επιλέγεται ως χώρος μελέτης το λιμάνι της θεσσαλονίκης, ένα βιομηχανικό τοπίο κοντά στο κέντρο της πόλης, όπου στη μεγαλύτερη έκτασή του, φαίνεται να μην αποτελεί ενεργό τμήμα του αστικού βίου. Με την αλλαγή της χρήσης κάποιων προϋπαρχουσών αποθηκών, καθώς και με το σχεδιασμό χώρων co-working, προσωπικής εργασίας και διεξαγωγής workshop, γίνεται μία προσπάθεια πολυεπίπεδης αναζωογόνησης της περιοχής. Τέλος, το χίασμα θρησκευτικής και αστικής λειτουργίας, επιδιώκει τον επαναπροσδιορισμό τόσο του ρόλου όσο και της σύγχρονης προσέγγισης των θρησκευτικών κτιρίων, προτείνοντας ένα νέο χωρικό διάλογο αμοιβαίας εξέλιξης του αστικού συνόλου και των χρηστών του.
Physical Human-Robot Interaction (pHRI) interfaces : a simulation based design method
Creators: name: John Varghese, Rohit
name: 0000-0001-7482-2654
Publisher: name: The University of Texas at Austin
Year: 2017
Subjects: Wearable robots
Design
Exoskeletons and orthoses

description: The design of effective and comfortable physical Human Robot Interaction (pHRI) interfaces for force transfer is a prominent challenge for coupled human-robot systems. Forces applied across the pHRI interface give rise to relative displacements across it. This is a result of the innate compliance of the system due to the presence of human soft tissue and device padding and can lead to errors in estimated position, as well as misalignment that could lead to discomfort or injury. Additionally, any loading applied by the robot creates reaction forces on the human body, often leading to high pressure concentrations at the interface which can cause pain and discomfort. In this thesis, we present a simulation environment that has been developed for the study of the pHRI interfaces and coupled human robot systems that involve them. The forces and displacements at the pHRI interfaces are systematically characterized via this simulation based approach, and a new method for design of these interfaces is presented. The simulation approach can be used along with appropriate human anthropometric data to design comfortable physical human robot interfaces for different parts of the human body as well. This can be especially useful when there is a transfer of high moment loads across small interface surfaces or very soft regions of the body. In this thesis, however we focus on the application of the simulation based approach to case studies of pHRI interfaces of hand orthoses, with specific use of the Maestro hand exoskeleton. Experimental characterization with the Maestro system and analytical studies of the same interfaces are also presented for comparison and verification of the numerical results given by our simulation approach.
Heinz-Lothar Barth (Hrsg.): Latein - Sprache der katholischen Kirche und des christlichen Abendlandes
Creators: name: Redaktion, Die
Publisher: name: Forum Classicum
Year: 2017

description: Rezension zu: Heinz-Lothar Barth (Hrsg.): Latein - Sprache der katholischen Kirche und des christlichen Abendlandes. Jaidhof: Rex Regum Verlag 2000. 155 S. (ISBN 3-901851-20-8).
description: Forum Classicum, Nr. 1 (2001): Forum Classicum