cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Interaction of Fundamental Forces and Formation of Black Holes in the Quantum Big Bounce
Creators: name: DEL AMO, Iñaki
Publisher: name: Zenodo
Year: 2024
Subjects: Quantum Big Bounce
Black Holes
Fundamental Forces
Higgs Field
Quantum Gravity
Early Universe
Non-Singular Cosmology
Supermassive Black Holes
General Relativity Corrections
Cosmic Microwave Background (CMB)
James Webb Space Telescope (JWST)
Gravitational Waves
Higher-Order Curvature
Cosmological Models
Relativistic Quantum Mechanics

description: This work presents a detailed analysis of the interaction between fundamental forces and the formation of black holes within the context of the Quantum Big Bounce model. The Quantum Big Bounce is proposed as an alternative to the classical Big Bang, offering a non-singular origin for the universe through the incorporation of quantum corrections to general relativity. These quantum corrections include higher-order curvature terms and the coupling of the Higgs field to spacetime curvature, ensuring mass generation remains effective even under extreme conditions. The model explores the dynamics of fundamental bosons such as gluons, Higgs, and gauge bosons (W and Z), showing how the early universe remains stable during the bounce phase, avoiding the pitfalls of singularities. The paper also presents a comparative analysis between the Quantum Big Bounce and Big Bang models, particularly regarding the early formation of supermassive black holes, and aligns its predictions with recent JWST observations. Future empirical validation is discussed through potential observations of gravitational waves (using LISA) and CMB anisotropies.

contact@inakidelamo.com
Note About Redefinition of BRST Operator for Pure Spinor String in General Background
Creators: name: Kluson, J.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss an analysis presented by N. Berkovits in [arXiv:0712.0324] in the context of classical mechanics and perform its extension to the case of pure spinor string in general background.
description: 24 pages, references added
Bouncing Cosmology in f(Q) Symmetric Teleparallel Gravity
Creators: name: Bajardi, Francesco
name: Vernieri, Daniele
name: Capozziello, Salvatore
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider f(Q) extended symmetric teleparallel cosmologies, where Q is the non-metricity scalar, and constrain its functional form through the order reduction method. By using this technique, we are able to reduce and integrate the field equations and thus to select the corresponding models giving rise to bouncing cosmology. The selected Lagrangian is then used to develop the Hamiltonian formalism and to obtain the Wave Function of the Universe which suggests that classical observable universes can be recovered according to the Hartle Criterion.
description: 11 pages, 1 figure, 68 references
Galois Groups in Rational Conformal Field Theory
Creators: name: Gepner, Doron
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: Rings and Algebras (math.RA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: It was established before that fusion rings in a rational conformal field theory (RCFT) can be described as rings of polynomials, with integer coefficients, modulo some relations. We use the Galois group of these relations to obtain a local set of equation for the points of the fusion variety. These equations are sufficient to classify all the RCFT, Galois group by Galois group. It is shown that the Galois group is equivalent to the pseudo RCFT group. We prove that the Galois groups encountered in RCFT are all abelian, implying solvability by radicals of the modular matrix.
description: 24 pages. Typos corrected
CODO: An Ontology for Collection and Analysis of Covid-19 Data
Creators: name: Dutta, B.
name: DeBellis, M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Information Retrieval (cs.IR)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences
subject: I.2.4

description: The COviD-19 Ontology for cases and patient information (CODO) provides a model for the collection and analysis of data about the COVID-19 pandemic. The ontology provides a standards-based open-source model that facilitates the integration of data from heterogeneous data sources. The ontology was designed by analysing disparate COVID-19 data sources such as datasets, literature, services, etc. The ontology follows the best practices for vocabularies by re-using concepts from other leading vocabularies and by using the W3C standards RDF, OWL, SWRL, and SPARQL. The ontology already has one independent user and has incorporated real-world data from the government of India.
The finite element solution of inverse problems in solid mechanics
Creators: name: McCullough, Andrew David Barbour
Publisher: name: University of British Columbia
Year: 2009

description: This thesis presents numerical procedures for solving inverse parameter identification problems in solid mechanics. These procedures are applied to the detection of subsurface flaws or cracks and to the study of propagating cracks. The procedure for detecting subsurface defects is based on the process of over-specifying the boundary conditions on the exposed surface of the structure, making an initial assessment about the damage, and then, with the use of nonlinear programming techniques, rninimizing a residual vector to reach an optimum solution. The residual vector contains unknown system parameters that characterize the internal defect. The finite element method is combined with a sequential quadratic programming algorithm to solve for these unknown parameters. The procedure utilizes finite element substructuring capabilities in order to minimize the processing and solution time for practical problems. The results obtained from the numerical study verify the accuracy of the algorithm. The finite element method and nonlinear optimization are also used to solve the inverse parameter identification problem of determining the direction a crack will propagate in a heterogeneous planar domain. This procedure involves determining the direction which produces the maximum strain energy release for a given increment of crack growth. The procedure is applied to four fracture cases of increasing complexity: a horizontal throughthickness crack in a finite plate; an inclined through-thickness crack in a finite plate; a crack parallel to a bimaterial interface; and a transverse crack in two fiber-reinforced composite materials. The results of this numerical study coincide with theoretical predictions and experimentally observed crack growth behavior.
Highly turbulent gas on GMC-scales in NGC 3256, the nearest luminous infrared galaxy
Creators: name: Brunetti, Nathan
name: Wilson, Christine D.
name: Sliwa, Kazimierz
name: Schinnerer, Eva
name: Aalto, Susanne
name: Peck, Alison B.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present the highest resolution CO (2-1) observations obtained to date (0.25") of NGC 3256 and use them to determine the detailed properties of the molecular interstellar medium in the central 6 kpc of this merger. Distributions of physical quantities are reported from pixel-by-pixel measurements at 55 and 120 pc scales and compared to disc galaxies observed by PHANGS-ALMA. Mass surface densities range from 8 to 5500 M$_{\odot}$ pc$^{-2}$ and velocity dispersions from 10 to 200 km s$^{-1}$. Peak brightness temperatures as large as 37 K are measured, indicating the gas in NGC 3256 may be hotter than all regions in nearby disc galaxies measured by PHANGS-ALMA. Brightness temperatures even surpass those in the overlap region of NGC 4038/9 at the same scales. The majority of the gas appears unbound with median virial parameters of 7 to 19, although external pressure may bind some of the gas. High internal turbulent pressures of 10$^{5}$ to 10$^{10}$ K cm$^{-3}$ are found. Given the lack of significant trends in surface density, brightness temperature, and velocity dispersion with physical scale we argue the molecular gas is made up of a smooth medium down to 55 pc scales, unlike the more structured medium found in the PHANGS-ALMA disc galaxies.
description: accepted to MNRAS, 21 pages, 8 figures
Beyond the Standard Model Explanations of GW190521
Creators: name: Sakstein, Jeremy
name: Croon, Djuna
name: McDermott, Samuel D.
name: Straight, Maria C.
name: Baxter, Eric J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The LIGO/Virgo collaboration has recently announced the detection of a heavy binary black hole merger, with component masses that cannot be explained by standard stellar structure theory. In this letter we propose several explanations based on models of new physics, including new light particle losses, modified gravity, large extra dimensions, and a small magnetic moment of the neutrino. Each of these affect the physics of the pair-instability differently, leading to novel mechanisms for forming black holes inside the black hole mass gap.
description: Four pages, one figure. Comments welcome
Η φορολογία των χρηματοοικονομικών προϊόντων
Creators: name: Πολυχρονίου, Στεφανία Σάββα
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: χρηματιστηριακά παράγωγα
χρηματοοικονομικά προϊόντα
φορολογία
financial derivatives
financial products
taxation

description: Στόχος της διπλωματικής εργασίας με τίτλο ‘‘Η φορολογία των χρηματοοικονομικών προϊόντων’’ είναι να αποτυπώσει το τρέχον νομοθετικό πλαίσιο φορολογικής μεταχείρισης των χρηματοοικονομικών προϊόντων ως αυτά προσδιορίζονται στις μετοχές, τα ομόλογα, τους τίτλους και τα ομόλογα Δημοσίου αλλά και τα παράγωγα χρηματοοικονομικά προϊόντα και ως αυτό το νομοθετικό πλαίσιο, εντοπίζεται στις διατάξεις του ισχύοντος (ν.4172/2013) Κώδικα Φορολογίας Εισοδήματος τόσο ως προς τα φυσικά όσο και ως προς τα νομικά πρόσωπα. Στην επί λόγω εργασία, συμπεριλαμβάνεται σύντομη ιστορική αναδρομή ως προς επίμαχες νομοθετικές διατάξεις έως και την ψήφιση του ισχύοντος νομοθετικού πλαισίου, αναλυτική περιγραφή των χρηματοοικονομικών προϊόντων ως οι κυριότερες μορφές αυτών εντοπίζονται στις συναλλαγές και αποτελούν αντικείμενο νομικής ρύθμισης, συγκεκριμένη μνεία ως προς την φορολογική μεταχείριση της υπεραξίας που προκύπτει από την μεταβίβαση παραγώγων και παρατηρήσεις σε σχέση με το διεθνές καθεστώς φορολογίας των χρηματοπιστωτικών παραγώγων, που διανθίζει την αρχική πλεύση της εργασίας δια συγκριτικής παράθεσης διεθνής φορολογικής μεταχείρισης και εν τέλει αναδεικνύει την εξαγωγή συμπερασμάτων επί του εύρους, των δυνατοτήτων και της αποτελεσματικότητας του ισχύοντος ελληνικού αλλά και του διεθνούς νομοθετικού πλαισίου επί της φορολογίας των χρηματοοικονομικών προϊόντων.
description: The aim of the thesis titled '' The taxation of financial products'' is to reflect the current legislative framework of the tax treatment of financial instruments as these are defined in stocks, bonds, securities and government bonds and financial derivatives and the way this legislative framework, lies in the provisions of the current (n.4172 / 2013) Income Tax Code both about physical and legal entities. On this work, is included a brief history regarding legislation in question until the adoption of the current legislative framework, a detailed description of financial products as the major forms of them are found in the transactions subject to legal regulation, specific reference as to the tax treatment of capital gains arising from the transfer of derivatives and observations in relation to the international regime for the taxation of financial derivatives, which embellishes the initial tack of work by comparative quote international tax treatment and ultimately brings conclusions on the scope, capacity and effectiveness current Greek and international legislative framework for the taxation of financial products.
On-line μετρήσεις αερίων ρύπων σε σταθμό μέτρησης ατμοσφαιρικής ρύπανσης εντός του Αριστοτελείου Πανεπιστημίου Θεσσαλονίκης
Creators: name: Βαλεριάνου, Κυριακή Αυγουστίνου
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: αέριοι ρύποι
αυτόματοι αναλυτές
μετεωρολογικές παράμετροι
air pollutants
automatic analyzers
meteorological parameters

description: Βασικό στόχο της παρούσας εργασίας αποτελεί η καταγραφή των τιμών των συγκεντρώσεων των αερίων ρύπων του όζοντος, των οξειδίων του αζώτου, των κλασμάτων των αιωρούμενων σωματιδίων και των αρωματικών υδρογονανθράκων βενζολίου, τολουολίου, αιθυλοβενζολίου και ξυλολίων, οι οποίες προέκυψαν από μετρήσεις με αυτόματους αναλυτές, σε Σταθμό Μέτρησης Ατμοσφαιρικής Ρύπανσης εντός του χώρου του Μετεωροσκοπείου του Α.Π.Θ., για το χρονικό διάστημα από τον Ιούλιο του 2013 έως και τον Ιανουάριο του 2014. Οι τιμές αυτές συλλέχθηκαν, επεξεργάσθηκαν και πραγματοποιήθηκε η στατιστική τους ανάλυση, με σκοπό να παρέχουν σαφή εικόνα για τα επίπεδα των συγκεκριμένων ρύπων εντός του Αριστοτελείου Πανεπιστημίου της Θεσσαλονίκης, καθώς και για τις συσχετίσεις μεταξύ τους και με τις μετεωρολογικές παραμέτρους της θερμοκρασίας, της σχετικής υγρασίας και της ταχύτητας του ανέμου. Επίσης, επιχειρήθηκε και μία σύγκριση των τιμών των μετρήσεων με άλλες παρόμοιες μετρήσεις ρύπων από κοντινούς στο Μετεωροσκοπείο του Α.Π.Θ. σταθμούς της Θεσσαλονίκης. Απώτερος στόχος της συγκεκριμένης μελέτης είναι οι εκτιμήσεις των μετρήσεων να αποτελέσουν, όσο αυτό είναι εφικτό, σημαντικό εργαλείο για τις υπεύθυνες αρχές αλλά και για τον ίδιο τον πολίτη, σχετικά με τη γνώση και την πρόληψη φαινομένων ατμοσφαιρικής ρύπανσης από τους ρύπους που μελετήθηκαν.
description: The main goal of this thesis is to record the concentration levels of ozone, nitrogen oxides, fractions of particulate matter and aromatic hydrocarbons of benzene, toluene, ethylbenzene and xylenes, which were measured with automatic analyzers in an Air Pollution Station into the Aristotle University of Thessaloniki from July 2013 to January 2014. The data of the concentration levels of the above air pollutants were measured, processed and statistically analysed, in order to provide a clear aspect of the levels of these pollutants into the Aristotle University of Thessaloniki, as well as the correlations between them and between the levels of air pollutants and the meteorological parameters of temperature, relative humidity and wind speed. Furthermore, a comparison of the above measurements with similar measurements from other nearby air pollution stations was attempted. The long-term goal of this thesis is the assessments of this measurements to become, as far as it is possible, an important tool for the responsible authorities and the citizens themselves in order to understand and finally to prevent in time air pollution phenomena.
Quantum-Cosmological Corrections and String Theory A Path Towards a Unified Theory of Everything
Creators: name: del amo, IÑAKI
Publisher: name: Zenodo
Year: 2024
Subjects: Quantum Cosmology
String Theory
Black Hole Physics
Dark Matter
Gravitational Waves
Cosmic Microwave Background
Theory of Everything, Singularities
Dark Matter Halos
Quantum Corrections

description: This paper explores quantum-cosmological corrections to black hole physics and early universe cosmology, focusing on their role in preventing singularities and handling quantum fluctuations. By integrating quantum corrections into the gravitational framework, we examine how string theory offers a promising foundation to regularize quantum fluctuations and unify the four fundamental forces: gravity, electromagnetism, the weak nuclear force, and the strong nuclear force. The work also provides empirical predictions for future observational data—such as anomalies in the Cosmic Microwave Background (CMB) and deviations in gravitational waves—that may serve as evidence for the proposed framework.

The paper includes simulations of quantum-corrected metrics that demonstrate how black hole singularities can be regularized and proposes that this approach forms the basis for a Theory of Everything (ToE), which integrates quantum mechanics with general relativity. Additionally, the study addresses the influence of quantum corrections on dark matter halo structures, providing insights into their potential to resolve the cusp-core problem and reduce dark matter annihilation rates in the densest halo regions.

This research serves as a stepping stone towards a more comprehensive understanding of the universe, combining theoretical advancements with testable predictions from ongoing and future experiments in astrophysics and cosmology.
Quantum-Cosmological Corrections and String Theory A Path Towards a Unified Theory of Everything
Creators: name: del Amo Castillo, Iñaki
Publisher: name: Zenodo
Year: 2024
Subjects: Quantum Cosmology
String Theory
Black Hole Physics
Dark Matter
Gravitational Waves
Cosmic Microwave Background
Theory of Everything, Singularities
Dark Matter Halos
Quantum Corrections

description: This paper explores quantum-cosmological corrections to black hole physics and early universe cosmology, focusing on their role in preventing singularities and handling quantum fluctuations. By integrating quantum corrections into the gravitational framework, we examine how string theory offers a promising foundation to regularize quantum fluctuations and unify the four fundamental forces: gravity, electromagnetism, the weak nuclear force, and the strong nuclear force. The work also provides empirical predictions for future observational data—such as anomalies in the Cosmic Microwave Background (CMB) and deviations in gravitational waves—that may serve as evidence for the proposed framework.

The paper includes simulations of quantum-corrected metrics that demonstrate how black hole singularities can be regularized and proposes that this approach forms the basis for a Theory of Everything (ToE), which integrates quantum mechanics with general relativity. Additionally, the study addresses the influence of quantum corrections on dark matter halo structures, providing insights into their potential to resolve the cusp-core problem and reduce dark matter annihilation rates in the densest halo regions.

This research serves as a stepping stone towards a more comprehensive understanding of the universe, combining theoretical advancements with testable predictions from ongoing and future experiments in astrophysics and cosmology.

contact@inakidelamo.com
Spin-orbit splitting and the tensor component of the Skyrme interaction
Creators: name: Colo', G.
name: Sagawa, H.
name: Fracasso, S.
name: Bortignon, P. F.
name: .
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We study the role of the tensor term of the Skyrme effective interactions on the spin-orbit splittings in the N=82 isotones and Z=50 isotopes. The different role of the triplet-even and triplet-odd tensor forces is pointed out by analyzing the spin-orbit splittings in these nuclei. The experimental isospin dependence of these splittings cannot be described by Hartree-Fock calculations employing the usual Skyrme parametrizations, but is very well accounted for when the tensor interaction is introduced. The capability of the Skyrme forces to reproduce binding energies and charge radii in heavy nuclei is not destroyed by the introduction of the tensor term. Finally, we also discuss the effect of the tensor force on the centroid of the Gamow-Teller states.
description: Submitted to Phys. Lett. B
Asexual and sexual replication in sporulating organisms
Creators: name: Lee, Bohyun
name: Tannenbaum, Emmanuel
Publisher: name: arXiv
Year: 2006
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: Cell Behavior (q-bio.CB)
subject: FOS: Biological sciences

description: This paper develops models describing asexual and sexual replication in sporulating organisms. Replication via sporulation is the replication strategy for all multicellular life, and may even be observed in unicellular life (such as with budding yeast). We consider diploid populations replicating via one of two possible sporulation mechanisms: (1) Asexual sporulation, whereby adult organisms produce single-celled diploid spores that grow into adults themselves. (2) Sexual sporulation, whereby adult organisms produce single-celled diploid spores that divide into haploid gametes. The haploid gametes enter a haploid "pool", where they may recombine with other haploids to form a diploid spore that then grows into an adult. We consider a haploid fusion rate given by second-order reaction kinetics. We work with a simplified model where the diploid genome consists of only two chromosomes, each of which may be rendered defective with a single point mutation of the wild-type. We find that the asexual strategy is favored when the rate of spore production is high compared to the characteristic growth rate from a spore to a reproducing adult. Conversely, the sexual strategy is favored when the rate of spore production is low compared to the characteristic growth rate from a spore to a reproducing adult. As the characteristic growth time increases, or as the population density increases, the critical ratio of spore production rate to organism growth rate at which the asexual strategy overtakes the sexual one is pushed to higher values. Therefore, the results of this model suggest that, for complex multicellular organisms, sexual replication is favored at high population densities, and low growth and sporulation rates.
description: 8 pages, 5 figures, to be submitted to Journal of Theoretical Biology, figures not included in this submission
Observation and laser spectroscopy of ytterbium monomethoxide, YbOCH$_3$
Creators: name: Augenbraun, Benjamin L.
name: Lasner, Zack D.
name: Frenett, Alexander
name: Sawaoka, Hiromitsu
name: Le, Anh T.
name: Doyle, John M.
name: Steimle, Timothy C.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We describe a laser spectroscopic study of ytterbium monomethoxide, YbOCH$_3$, a species of interest to searches for time-reversal symmetry violation using laser-cooled molecules. We report measurements of vibrational structure in the $\tilde{X}$ and $\tilde{A}$ states, vibrational branching ratios for several components of the $\tilde{A}$ state, and radiative lifetimes of low-lying electronic states. $\textit{Ab initio}$ calculations are used to aid the assignment of vibronic emission bands and provide insight into the electronic and vibrational structure. Our results demonstrate that rapid optical cycling is feasible for YbOCH$_3$, opening a path to orders-of-magnitude increased sensitivity in future measurements of P- and/or T-violating physics.
description: 14 pages, 5 figures
Transmission in a Fano-Anderson chain with a topological defect
Creators: name: Nehra, Ritu
name: Ramachandran, Ajith
name: Wüster, Sebastian
name: Sharma, Auditya
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The Fano-Anderson chain consists of a linear lattice with a discrete side-unit, and exhibits Fano-resonant scattering due to coupling between the discrete states of the side-unit with the tight-binding continuum. We study Fano-resonance-assisted transport for the case of a topologically non-trivial side unit. We find that the topology of the side unit influences the transmission characteristics which thus can be an effective detection tool of the topological phases of the side unit. Furthermore, we explore the role of dual links between the linear tight-binding chain and the side unit. The secondary connection between the main chain and the side unit can modify the position or width of the Fano resonance dip in the transmission probability, and thus yield additional control.
Updates to the One-loop Provider NLOX
Creators: name: Figueroa, Diogenes
name: Quackenbush, Seth
name: Reina, Laura
name: Reuschle, Christian
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We describe the 1.2 update to NLOX, a computer program for calculations in high-energy particle physics. New features since the 1.0 release and other changes are described, along with usage documentation.
description: 8 pages
Planar projections of graphs
Creators: name: Aravind, N. R.
name: Maniyar, Udit
Publisher: name: arXiv
Year: 2020
Subjects: subject: Discrete Mathematics (cs.DM)
subject: FOS: Computer and information sciences

description: We introduce and study a new graph representation where vertices are embedded in three or more dimensions, and in which the edges are drawn on the projections onto the axis-parallel planes. We show that the complete graph on $n$ vertices has a representation in $\lceil \sqrt{n/2}+1 \rceil$ planes. In 3 dimensions, we show that there exist graphs with $6n-15$ edges that can be projected onto two orthogonal planes, and that this is best possible. Finally, we obtain bounds in terms of parameters such as geometric thickness and linear arboricity. Using such a bound, we show that every graph of maximum degree 5 has a plane-projectable representation in 3 dimensions.
description: Accepted at CALDAM 2020
A Parallel Mesh-Adaptive Framework for Hyperbolic Conservation Laws
Creators: name: Dreher, J.
name: Grauer, R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: We report on the development of a computational framework for the parallel, mesh-adaptive solution of systems of hyperbolic conservation laws like the time-dependent Euler equations in compressible gas dynamics or Magneto-Hydrodynamics (MHD) and similar models in plasma physics. Local mesh refinement is realized by the recursive bisection of grid blocks along each spatial dimension, implemented numerical schemes include standard finite-differences as well as shock-capturing central schemes, both in connection with Runge-Kutta type integrators. Parallel execution is achieved through a configurable hybrid of POSIX-multi-threading and MPI-distribution with dynamic load balancing. One- two- and three-dimensional test computations for the Euler equations have been carried out and show good parallel scaling behavior. The Racoon framework is currently used to study the formation of singularities in plasmas and fluids.
description: late submission
Study of UV bright stellar populations in the globular cluster NGC 1261 using AstroSat
Creators: name: Rani, Sharmila
name: Pandey, Gajendra
name: Subramaniam, Annapurni
name: Sahu, Snehalata
name: Rao, N. Kameshwara
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present the UV photometry of the globular cluster NGC 1261 using images acquired with the Ultraviolet Imaging Telescope (UVIT) on-board ASTROSAT. We performed PSF photometry on four near-UV (NUV) and two far-UV (FUV) images and constructed UV colour-magnitude diagrams (CMDs), in combination with HST, Gaia, and ground-based optical photometry for member stars. We detected the full horizontal branch (HB) in NUV, blue HB in the FUV and identified two extreme HB (EHB) stars. HB stars have a tight sequence in UV-optical CMDs well-fitted with isochrones generated (12.6 Gyr age, [Fe/H] = -1.27 metallicity) using updated BaSTI-IAC models. Effective temperatures (Teff), luminosities and radii of bright HB stars were estimated using spectral energy distribution. As we detect the complete sample of UV bright HB stars, the hot end of the HB distribution is found to terminate at the G-jump (Teff ~ 11500 K). The two EHB stars, fitted well with single spectra, have Teff= 31,000 K and a mass = 0.495Msun and follow the same Teff-Radius relation of the blue HB stars. We constrain the formation pathways of these EHB stars to extreme mass loss in the RGB phase (either due to rotation or enhanced Helium), OR early hot-flash scenario.
description: 13 pages, 9 figures, 3 tables, Accepted for publication in MNRAS
Strongly coupled charge, orbital and spin order in TbTe$_{3}$
Creators: name: Chillal, S.
name: Schierle, E.
name: Weschke, E.
name: Yokaichiya, F.
name: Hoffmann, J. -U.
name: Volkova, O. S.
name: Vasiliev, A. N.
name: Sinchenko, A. A.
name: Lejay, P.
name: Hadj-Azzem, A.
name: Monceau, P.
name: Lake, B.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report a ground state with strongly coupled magnetic and charge density wave orders mediated via orbital ordering in the layered compound \tbt. In addition to the commensurate antiferromagnetic (AFM) and charge density wave (CDW) orders, new magnetic peaks are observed whose propagation vector equals the sum of the AFM and CDW propagation vectors, revealing an intricate and highly entwined relationship. This is especially interesting given that the magnetic and charge orders lie in different layers of the crystal structure where the highly localized magnetic moments of the Tb$^{3+}$ ions are netted in the Tb-Te stacks, while the charge order is formed by the conduction electrons of the adjacent Te-Te layers. Our results, based on neutron diffraction and resonant x-ray scattering reveal that the charge and magnetic subsystems mutually influence each other via the orbital ordering of Tb$^{3+}$ ions.
description: 5 pages, 4 figures
Universal Extremal Statistics in a Freely Expanding Jepsen Gas
Creators: name: Bena, Ioana
name: Majumdar, Satya N.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Biological Physics (physics.bio-ph)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: We study the extremal dynamics emerging in an out-of-equilibrium one-dimensional Jepsen gas of $(N+1)$ hard-point particles. The particles undergo binary elastic collisions, but move ballistically in-between collisions. The gas is initally uniformly distributed in a box $[-L,0]$ with the "leader" (or the rightmost particle) at X=0, and a random positive velocity, independently drawn from a distribution $ϕ(V)$, is assigned to each particle. The gas expands freely at subsequent times. We compute analytically the distribution of the leader's velocity at time $t$, and also the mean and the variance of the number of collisions that are undergone by the leader up to time $t$. We show that in the thermodynamic limit and at fixed time $t\gg 1$ (the so-called "growing regime"), when interactions are strongly manifest, the velocity distribution exhibits universal scaling behavior of only three possible varieties, depending on the tail of $ϕ(V)$. The associated scaling functions are novel and different from the usual extreme-value distributions of uncorrelated random variables. In this growing regime the mean and the variance of the number of collisions of the leader up to time $t$ increase logarithmically with $t$, with universal prefactors that are computed exactly. The implications of our results in the context of biological evolution modeling are pointed out.
description: 13 pages, 3 figures. To appear in Phys. Rev. E
Approximating the long time average of the density operator: Diagonal ensemble
Creators: name: Çakan, Aslı
name: Cirac, J. Ignacio
name: Bañuls, Mari Carmen
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: For an isolated generic quantum system out of equilibrium, the long time average of observables is given by the diagonal ensemble, i.e. the mixed state with the same probability for energy eigenstates as the initial state but without coherences between different energies. In this work we present a method to approximate the diagonal ensemble using tensor networks. Instead of simulating the real time evolution, we adapt a filtering scheme introduced earlier in [Phys. Rev. B 101, 144305 (2020)] to this problem. We analyze the performance of the method on a non-integrable spin chain, for which we observe that local observables converge towards thermal values polynomially with the inverse width of the filter.
description: 9 pages, 9 figures
Ονειρικό φως και εφιαλτικές σκιές στα διηγήματα του E.T.A. Χόφμαν: Κόσμος μαγικός, εσώτερος και φροϋδικό ασυνείδητο. Μια κατοπτρική σχέση.
Creators: name: Ιωαννίδου, Σωσάνα Δαμιανού
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Χόφμαν
Ρομαντισμός
Ψυχανάλυση
Hoffmann
Romanticism
Psychoanalysis

description: Σκοπός της διπλωματικής εργασίας ήταν η ανάδειξη της κατοπτρικής σχέσης του έργου του Ε.Τ.Α. Χόφμαν και του Σίγκμουντ Φρόιντ. Τόσο ο Φρόιντ μέσω της επιστήμης όσο και ο Χόφμαν μέσω της τέχνης έχοντας ως εφαλτήριο το κοινό πολιτισμικό πλαίσιο, τις ρομαντικές καταβολές της εποχής τους, αναδεικνύουν την αγωνία του ανθρώπου για εσωτερική αναζήτηση. Οι συγκεκριμένες καλλιτεχνικές επιλογές του Χόφμαν και η διαμόρφωση της επιστημονικής θεωρίας του Φρόιντ πηγάζουν από τη φιλοσοφική, ρομαντική κοσμοθεώρηση μιας εποχής, όπου το βλέμμα στρέφεται στον εσωτερικό κόσμο του ονείρου και της φαντασίας. Έτσι αφού έγινε αναφορά στις φιλοσοφικές και αισθητικές προκείμενες του ρομαντισμού και του φιλοσοφικού υπόβαθρου που το στηρίζει, παρουσιάστηκε το κύριο θεωρητικό πλαίσιο της ψυχαναλυτικής θεωρίας του Φρόιντ με σκοπό στη συνέχεια να στοιχηθεί κατοπτρικά με τα διηγήματα του Χόφμαν, ώστε να φωτιστούν εκατέρωθεν.
description: The aim of this thesis was to highlight the mirror relationship between Hoffman and Sigmund Freud. Having as starting point the common cultural context, romantic origins of their time, Freud through science and Hofmann through art highlight the anguish of man's internal search. The artistic choices of Hoffmann and the formulation of scientific theory of Freud stem from the philosophical, romantic worldview of an era, where the gaze is directed to the inner world of dreams and imagination. After referring to philosophical and aesthetic premisses of romance and its philosophical background, is presented the main theoretical framework of psychoanalytic theory of Freud in order to compare the works of Hoffmann and Freud and spot their common roots.
Εμπειρίες και Απόψεις Εκπαιδευτικών για τα «Εκπαιδευτικά Πακέτα» της Αγγλικής Γλώσσας των Ολοήμερων Σχολείων με Ενιαίο Αναμορφωμένο Εκπαιδευτικό Πρόγραμμα
Creators: name: Κομπογιάννη, Ιουλία Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: εκπαιδευτικό υλικό
ολοήμερο σχολείο
εκμάθηση της Αγγλικής σε πρώιμη παιδική ηλικία
educational material
all-day school
early English language learning

description: Σκοπός της παρούσας εργασίας αποτέλεσε η εξέταση των απόψεων και των εμπειριών των εκπαιδευτικών που διδάσκουν το μάθημα των Αγγλικών στα Ολοήμερα Σχολεία με Ενιαίο Αναμορφωμένο Εκπαιδευτικό Πρόγραμμα αναφορικά με τα εκπαιδευτικά πακέτα του παραπάνω μαθήματος στην Α΄ και Β΄ τάξη του δημοτικού σχολείου. Το πρώτο μέρος της εργασίας εξετάζει από θεωρητική σκοπιά θέματα που αφορούν στις προδιαγραφές της εκπαιδευτικής διαδικασίας με αναφορά στη θεωρία γύρω από τα αναλυτικά προγράμματα και το εκπαιδευτικό υλικό, καθώς και τη σχέση των εκπαιδευτικών με τις προδιαγραφές. Ακόμη, αναφέρεται στο θεσμό του Ολοήμερου Σχολείου εξετάζοντας την εξέλιξή του, τους λόγους που επέβαλαν την εμφάνισή του και τους τύπους Ολοήμερων Σχολείων που εφαρμόστηκαν στην Ελλάδα, με αναφορά στα Ολοήμερα Σχολεία με Ενιαίο Αναμορφωμένο Εκπαιδευτικό Πρόγραμμα που απασχολούν την παρούσα εργασία. Τέλος, εξετάζεται το θέμα της διδασκαλίας της Αγγλικής στην Πρωτοβάθμια Εκπαίδευση με έμφαση στη διδασκαλία σε πρώιμη παιδική ηλικία και παρουσιάζεται το ΠΕΑΠ και τα ιδιαίτερα χαρακτηριστικά του. Στο ερευνητικό μέρος της εργασίας παρουσιάζεται ο σκοπός, τα ερευνητικά ερωτήματα και η μεθοδολογία της έρευνας και ακολουθεί η ανάλυση του συλλεχθέντος υλικού. Τέλος, παρατίθεται η συζήτηση και οι διαπιστώσεις.
description: The aim of the present paper was to examine the views and experiences of educators who teach English on the A and B grade in All-day Schools with a Unified Reformed Educational Curriculum concerning the teaching-learning material provided for these grades. The first part of the paper examines from a theoretical point of view aspects concerning the theory on curriculum studies and educational material as well as the relationship between educators and the curriculum. It also refers to the institution of All-day Schools examining their evolution, the reasons for their appearance and the different types of All-day Schools implemented in Greece, and particularly the All-day Schools with a Unified Reformed Educational Curriculum, that concern the present study. Finally, it examines the issue of teaching English as a foreign language in Primary Education, focusing on early English language teaching and it refers to PEAP and its characteristics. The research part of the paper contains the a presentation of the aim, the research questions and the methodology used followed by the analysis of the collected material. The paper closes with a discussion about the findings of the research.
Decay and Subluminality of Modes of all Wave Numbers in the Relativistic Dynamics of Viscous and Heat Conductive Fluids
Creators: name: Freistühler, Heinrich
name: Reintjes, Moritz
name: Temple, Blake
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 76R99 (primary), 83A05 (secondary)

description: To further confirm the causality and stability of a second-order hyperbolic system of partial differential equations that models the relativistic dynamics of barotropic fluids with viscosity and heat conduction (H. Freistühler and B. Temple, J. Math. Phys. 59 (2018)), this paper studies the Fourier-Laplace modes of this system and shows that all such modes, relative to arbitrary Lorentz frames, (a) decay with increasing time and (b) travel at subluminal speeds. Stability is also shown for the related model of non-barotropic fluids (H. Freistühler and B. Temple. Proc. R. Soc. A 470 (2014) and Proc. R. Soc. A 473 (2017)). Even though these properties had been known for a while in the sense of numerical evidence, the fully analytical proofs for the subluminality of modes of arbitrary wave numbers in arbitrary frames given here appear to be the first regarding any five-field formulation of dissipative relativistic fluid dynamics.
description: 19 pages
Massless scalar field in two-dimensional de Sitter universe
Creators: name: Bertola, Marco
name: Corbetta, Francesco
name: Moschella, Ugo
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We study the massless minimally coupled scalar field on a two--dimensional de Sitter space-time in the setting of axiomatic quantum field theory. We construct the invariant Wightman distribution obtained as the renormalized zero--mass limit of the massive one. Insisting on gauge invariance of the model we construct a vacuum state and a Hilbert space of physical states which are invariant under the action of the whole de Sitter group. We also present the integral expression of the conserved charge which generates the gauge invariance and propose a definition of dual field.
description: 13 pages
Optimal Measurement of Field Properties with Quantum Sensor Networks
Creators: name: Qian, Timothy
name: Bringewatt, Jacob
name: Boettcher, Igor
name: Bienias, Przemyslaw
name: Gorshkov, Alexey V.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider a quantum sensor network of qubit sensors coupled to a field $f(\vec{x};\vecθ)$ analytically parameterized by the vector of parameters $\vecθ$. The qubit sensors are fixed at positions $\vec{x}_1,\dots,\vec{x}_d$. While the functional form of $f(\vec{x};\vecθ)$ is known, the parameters $\vecθ$ are not. We derive saturable bounds on the precision of measuring an arbitrary analytic function $q(\vecθ)$ of these parameters and construct the optimal protocols that achieve these bounds. Our results are obtained from a combination of techniques from quantum information theory and duality theorems for linear programming. They can be applied to many problems, including optimal placement of quantum sensors, field interpolation, and the measurement of functionals of parametrized fields.
description: 15 pages, 1 figure
Μεταφρασμένη λογοτεχνία στα ανθολόγια της πρωτοβάθμιας εκπαίδευσης: σχέση κειμένου και εικόνας
Creators: name: Αθανασιάδου, Νικολέτα Κλεάνθη
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Λογοτεχνία στην πρωτοβάθμια εκπαίδευση
Μεταφρασμένη λογοτεχνία
Ανθολόγιο
Literature in primary education
Translated literature
Anthology

description: Η μετάφραση, ως διαδικασία και ως αποτέλεσμα, διαθέτει τα κατάλληλα γνωρίσματα για να εξυπηρετήσει τους σκοπούς της παιδαγωγικής σε σχέση με την ανάδειξη της διαφορετικότητας, καθώς ένα μεταφρασμένο κείμενο, ως φορέας ενός ξένου πολιτισμού, γίνεται το μέσο που θα βοηθήσει τους μαθητές να γνωρίσουν αυτόν τον άγνωστο πολιτισμό. Ταυτόχρονα, η σύγχρονη εποχή έχει αναδείξει ένα νέο μέσο επικοινωνίας και μετάδοσης πληροφοριών και μηνυμάτων, την εικόνα. Η παρούσα εργασία, λοιπόν, μελετά τη σχέση του μεταφρασμένου κειμένου με την εικόνα. Ειδικότερα, εξετάζει τα μεταφρασμένα λογοτεχνικά κείμενα και τις αντίστοιχες εικόνες που περιλαμβάνονται στα τρία τεύχη του Ανθολογίου Λογοτεχνικών Κειμένων, τα οποία χρησιμοποιούνται για τη διδασκαλία της λογοτεχνίας στην ελληνική πρωτοβάθμια εκπαίδευση και αντιστοιχούν σε τρία ζεύγη τάξεων του δημοτικού σχολείου: Α΄ και Β΄, Γ΄ και Δ΄ και Ε΄ και ΣΤ΄. Το επίκεντρο της μελέτης αποτελούν οι τίτλοι των κειμένων και οι εικόνες που συνοδεύουν τα εν λόγω κείμενα. Για την ανάλυσή τους, η έρευνα δανείζεται μεθοδολογικά εργαλεία από το επιστημονικό πεδίο της σημειωτικής. Σκοπός είναι να διερευνήσει αρχικά τους κώδικες και τα θέματα που κρύβονται στο κείμενο και στην εικόνα και στη συνέχεια τη μεταξύ τους σχέση και το αν συμβάλλουν στην επικοινωνία μεταξύ των διαφορετικών πολιτισμών που εμπλέκονται στη μεταφραστική διαδικασία και γίνονται αντικείμενο επεξεργασίας κατά την εκπαιδευτική διαδικασία.
description: Translation, as a process and as an outcome, has the appropriate characteristics to serve the purposes of pedagogy regarding the emergence of dissimilarity, because a translated text brings out a foreign culture and becomes the means that helps students know that unfamiliar culture. At the same time, a new means of communication and transmission of information and messages has nowadays emerged; image. The present thesis studies the relationship between a translated text and an image. Namely, it examines the translated literature texts and their illustrations that are included in the three issues of the Anthology of Literature Texts, used for teaching literature in Greek primary education and corresponding to three couples of grades in elementary school; 1st and 2nd, 3rd and 4th, 5th and 6th. The research focuses on the texts’ titles and the images that accompany them. For their analysis, research borrows its methodological tools from the scientific field of semiotics. Its initial aim is to examine the codes and themes hidden in the texts and images and subsequently their relationship and whether they contribute to the communication of different cultures involved in the procedure of translating and being processed during the educational procedure.
American Sign Language Recognition Using RF Sensing
Creators: name: Gurbuz, Sevgi Z.
name: Gurbuz, Ali C.
name: Malaia, Evie A.
name: Griffin, Darrin J.
name: Crawford, Chris
name: Rahman, M. Mahbubur
name: Kurtoglu, Emre
name: Aksu, Ridvan
name: Macks, Trevor
name: Mdrafi, Robiulhossain
Publisher: name: arXiv
Year: 2020
Subjects: subject: Signal Processing (eess.SP)
subject: Human-Computer Interaction (cs.HC)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Many technologies for human-computer interaction have been designed for hearing individuals and depend upon vocalized speech, precluding users of American Sign Language (ASL) in the Deaf community from benefiting from these advancements. While great strides have been made in ASL recognition with video or wearable gloves, the use of video in homes has raised privacy concerns, while wearable gloves severely restrict movement and infringe on daily life. Methods: This paper proposes the use of RF sensors for HCI applications serving the Deaf community. A multi-frequency RF sensor network is used to acquire non-invasive, non-contact measurements of ASL signing irrespective of lighting conditions. The unique patterns of motion present in the RF data due to the micro-Doppler effect are revealed using time-frequency analysis with the Short-Time Fourier Transform. Linguistic properties of RF ASL data are investigated using machine learning (ML). Results: The information content, measured by fractal complexity, of ASL signing is shown to be greater than that of other upper body activities encountered in daily living. This can be used to differentiate daily activities from signing, while features from RF data show that imitation signing by non-signers is 99\% differentiable from native ASL signing. Feature-level fusion of RF sensor network data is used to achieve 72.5\% accuracy in classification of 20 native ASL signs. Implications: RF sensing can be used to study dynamic linguistic properties of ASL and design Deaf-centric smart environments for non-invasive, remote recognition of ASL. ML algorithms should be benchmarked on native, not imitation, ASL data.
description: submitted