cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: Ζήση και γειτνίαση σε ένα μαχαλά του Άργους, υπό όρους παλίμψηστου
Creators: name: Καρδαράκου Κωνσταντίνα Μαρία
Publisher: name: Technical University of Crete
Year: 2012

description: Μη διαθέσιμο
Diffraction imaging of light induced dynamics in xenon-doped helium nanodroplets
Creators: name: Langbehn, Bruno
name: Ovcharenko, Yevheniy
name: Clark, Andrew
name: Coreno, Marcello
name: Cucini, Riccardo
name: Demidovich, Alexander
name: Drabbels, Marcel
name: Finetti, Paola
name: Di Fraia, Michele
name: Giannessi, Luca
name: Grazioli, Cesare
name: Iablonskyi, Denys
name: LaForge, Aaron C.
name: Nishiyama, Toshiyuki
name: de Lara, Verónica Oliver Álvarez
name: Peltz, Christian
name: Piseri, Paolo
name: Plekan, Oksana
name: Sander, Katharina
name: Ueda, Kiyoshi
name: Fennel, Thomas
name: Prince, Kevin C.
name: Stienkemeier, Frank
name: Callegari, Carlo
name: Möller, Thomas
name: Rupp, Daniela
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We have explored the light induced dynamics in superfluid helium nanodroplets with wide-angle scattering in a pump-probe measurement scheme. The droplets are doped with xenon atoms to facilitate the ignition of a nanoplasma through irradiation with near-infrared laser pulses. After a variable time delay of up to 800 ps, we image the subsequent dynamics using intense extreme ultraviolet pulses from the FERMI free-electron laser. The recorded scattering images exhibit complex intensity fluctuations that are categorized based on their characteristic features. Systematic simulations of wide-angle diffraction patterns are performed, which can qualitatively explain the observed features by employing model shapes with both randomly distributed as well as structured, symmetric distortions. This points to a connection between the dynamics and the positions of the dopants in the droplets. In particular, the structured fluctuations might be governed by an underlying array of quantized vortices in the superfluid droplet as has been observed in previous small-angle diffraction experiments. Our results provide a basis for further investigations of dopant-droplet interactions and associated heating mechanisms.
description: 24 pages, 8 figures, 1 table
Coevolution and correlated multiplexity in multiplex networks
Creators: name: Kim, Jung Yeol
name: Goh, K. -I.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Social and Information Networks (cs.SI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Distinct channels of interaction in a complex networked system define network layers, which co-exist and co-operate for the system's function. Towards realistic modeling and understanding such multiplex systems, we introduce and study a class of growing multiplex network models in which different network layers coevolve, and examine how the entangled growth of coevolving layers can shape the overall network structure. We show analytically and numerically that the coevolution can induce strong degree correlations across layers, as well as modulate degree distributions. We further show that such a coevolution-induced correlated multiplexity can alter the system's response to dynamical process, exemplified by the suppressed susceptibility to a threshold cascade process.
description: 5 pages, 4 figures, published in PRL
Given Meaning: Centering the Work of Data Visualization in Instruction
Creators: name: Joque, Justin
name: Sonnichsen, Amy
name: Rutkowski, Andy
name: Clement, Ryan
Publisher: name: Zenodo
Year: 2021

description: This panel will focus on the relationship between data visualization and the production of meaning. The panelists will address teaching data visualization skills, especially to undergraduate students, in ways that center literacy, representation, design, aesthetics and critical approaches rather than exclusively focusing on specific technologies and tools. Amy Sonnichsen will discuss how visualization was the combinative factor in centering a course on community and interdisciplinary scholarship. She will share the instructional outcomes that emerged in the classroom through the focus on methods for making meaning and visual connections between data and disciplines. Andy Rutkowski will explain the concept of "writing with technology" in the context of a freshman writing course. He will focus on the importance of making space and time in the creation and interpretation of visualizations and how the process of visualizing data is sometimes more important than the end results. Justin Joque will focus on the work of French cartographer Jacques Bertin, especially from his 1960s text The Semiology of Graphics. This work provides an enduring foundation from which to understand visualization. This presentation will provide a critical overview of core concepts and suggest its continued relevance to understanding and teaching data visualization. Ryan Clement will explore teaching novices (e.g. new librarians, first-year undergrads, unfamiliar faculty) about data visualization as a form of communicating. Drawing from recent research and work, he will address the particular challenges and solutions in working with novices, and how this can complement/challenge the 'in-class' lessons from faculty. This work grows out of the IMLS funded "Visualizing the Future" grant (RE-73-18-0059-18) designed to develop a literacy-based instructional and research agenda for library and information professionals advancing data visualization instruction and use beyond hands-on, technology-based tutorials toward a nuanced, critical understanding. All four panelists are currently working on the grant project.
Unifying attractor and non-attractor models of inflation under a single soft theorem
Creators: name: Bravo, Rafael
name: Palma, Gonzalo A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study the generation of local non-Gaussianity in models of canonical single field inflation when their backgrounds are either attractor or non-attractor. We show that the invariance of inflation under space-time diffeomorphisms can be exploited to make powerful statements about the squeezed limit of the primordial bispectrum of curvature perturbations, valid to all orders in slow roll parameters. In particular, by neglecting departures from the adiabatic evolution of long-wavelength modes (for instance, produced in sharp transitions between slow-roll and ultra slow-roll phases), we derive a general expression for the bispectrum's squeezed limit in co-moving coordinates. This result consists in the standard Maldacena's consistency relation (proportional to the spectral index of the power spectrum) plus additional terms containing time derivatives of the power spectrum. In addition, we show that it is always possible to write the perturbed metric in conformal Fermi coordinates, independently of whether the inflationary background is attractor or non-attractor, allowing the computation of the physical primordial bispectrum's squeezed limit as observed by local inertial observers. We find that in the absence of sudden transitions between attractor and non-attractor regimes, observable local non-Gaussianity is generically suppressed. Our results imply that large local non-Gaussianity is not a generic consequence of non-attractor backgrounds.
description: 13 pages; v5: matches published version in Phys Rev D. We included a discussion regarding adiabaticity during USR-SR transitions
Regularized phase-space volume for the three-body problem
Creators: name: Dandekar, Yogesh
name: Kol, Barak
name: Lederer, Lior
name: Mazumdar, Subhajit
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The micro-canonical phase-space volume for the three-body problem is an elementary quantity of intrinsic interest, and within the flux-based statistical theory, it sets the scale of the disintegration time. While the bare phase-volume diverges, we show that a regularized version can be defined by subtracting a reference phase-volume, which is associated with hierarchical configurations. The reference quantity, also known as a counter-term, can be chosen from a 1-parameter class. The regularized phase-volume of a given (negative) total energy, $\barσ(E)$, is evaluated. First, it is reduced to a function of the masses only, which is sensitive to the choice of a regularization scheme only through an additive constant. Then, analytic integration is used to reduce the integration to a sphere, known as shape sphere. Finally, the remaining integral is evaluated numerically, and presented by a contour plot in parameter space. Regularized phase-volumes are presented for both the planar three-body system and the full 3d system. In the test mass limit, the regularized phase-volume is found to become negative, thereby signalling the breakdown of the non-hierarchical statistical theory. This work opens the road to the evaluation of $\barσ(E,L)$, where $L$ is the total angular momentum, and it turn, to comparison with simulation determined disintegration times.
description: 27 pages, 6 figures
Examples of exact exponential cosmological solutions with three isotropic subspaces in the Einstein-Gauss-Bonnet gravity
Creators: name: Ernazarov, K. K.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We consider $(1+ 8)$- and $(1+10)$-dimensional Einstein-Gauss-Bonnet models with the cosmological $Λ$-term. Some new examples of exact solutions with three constant Hubble-like parameters in this model are obtained, governed by three non-coinciding Hubble-like parameters: $H \neq 0$, $h_1$ and $h_2$, obeying $m H + k_1 h_1 + k_2 h_2 \neq 0$, corresponding to factor spaces of dimensions $m\geqslant 3$, $ k_1 > 1$ and $ k_2\geqslant 1$. In this case, the multidimensional cosmological model deals with three factor spaces: the external 3-dimensional "our" world and internal subspaces with dimensions $ (m-3)$, $k_1$ and $k_2$.
description: 18 pages
Measurements on release-recapture of cold Rb-85 atoms using an optical nanofibre in a magneto-optical trap
Creators: name: Russell, L.
name: Kumar, R.
name: Tiwari, V. B.
name: Chormaic, S. Nic
Publisher: name: arXiv
Year: 2013
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We have performed release-recapture temperature measurements of laser-cooled Rb-85 atoms using an optical nanofibre (ONF) in a magneto-optical trap (MOT). The effects of changing the cooling laser light-shift parameter on the temperature of the cold atoms and spring constant of the trap are studied. By varying the cold atom number density near the ONF, the onset of the multiple scattering regime is observed without the need for an estimation of the atom cloud size. Moreover, this sensitive ONF assisted release-recapture technique is easily able to detect any optical misalignment of the cooling laser beams in the MOT.
description: 17 pages, 7 figures
Mode switching dynamics in organic polariton lasing
Creators: name: Moilanen, Antti J.
name: Arnardóttir, Kristín B.
name: Keeling, Jonathan
name: Törmä, Päivi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We study the dynamics of multimode polariton lasing in organic microcavities by using a second-order cumulant equation approach. By inspecting the time evolution of the photon mode occupations, we show that if multiple lasing peaks are observed in time-integrated mode occupations, the reason can be either bi-modal lasing or temporal switching between several modes. The former takes place within a narrow range of parameters while the latter occurs more widely. We find that the origin of the temporal switching is different in the weak- and strong-coupling regimes. At weak coupling slope efficiency is the determining factor, while for strong coupling it is changes in the eigenmodes and gain spectrum upon pumping. This difference is revealed by investigating the photoluminescence and momentum-resolved gain spectra. Our results underscore the importance of understanding the time evolution of the populations when characterizing the lasing behaviour of a multimode polariton system, and show how these features differ between weak and strong coupling.
description: 15 pages, 13 figures
Do eddies connect the tropical Atlantic Ocean and the Gulf of Mexico?
Creators: name: Andrade-Canto, F.
name: Beron-Vera, F. J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Consistent with satellite-tracked trajectories of drogued drifters, but at odds with Eulerian assessment of satellite-altimetry measurements of sea-surface height, we show that North Brazil Currents Rings (NBCRs) are incapable of bypassing the Lesser Antilles as structures that coherently transport material. The nature of the inability of the de-facto oceanographic Eulerian, streamline-based eddy detection technique to produce a correct assessment is rooted in its lack of objectivity. We arrive at this conclusion by applying \emph{geodesic eddy detection} on the altimetric dataset over nearly its entire extent. While we detect northwestward translating NBCRs that can be classified as coherent Lagrangian eddies, they typically experience strong filamentation and complete loss of coherence prior to reaching the Lesser Antilles. Moreover, the filamented material hardly penetrates into the Caribbean Sea, let alone the Gulf of Mexico, and not without substantively mixing with the ambient fluid east of the archipelago.
description: Submitted to Geophysical Research Letters. Typos and references fixed. Appendices added showing robustness of geodesic boundaries under flow perturbations; support for the x-to-o behavior in the bottom panels of Fig.~1; and proof of the lack of objectivity of PV
Cutkosky's Theorem for Massive One-Loop Feynman Integrals -- Part 1
Creators: name: Mühlbauer, Maximilian
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences
subject: 32A12, 81U20 (Primary) 32A27, 81T18 (Secondary)

description: We formulate and prove Cutkosky's Theorem regarding the discontinuity of Feynman integrals in the massive one-loop case up to the involved intersection index. This is done by applying the techniques to treat singular integrals developed in \cite{app-iso}. We write one-loop integrals as an integral of a holomorphic family of holomorphic forms over a compact cycle. Then, we determine at which points simple pinches occur and explicitly compute a representative of the corresponding vanishing sphere. This also yields an algorithm to compute the Landau surface of a one-loop graph without explicitly solving the Landau equations. We also discuss the bubble, triangle and box graph in detail.
Poseidon: Mitigating Interest Flooding DDoS Attacks in Named Data Networking
Creators: name: Compagno, Alberto
name: Conti, Mauro
name: Gasti, Paolo
name: Tsudik, Gene
Publisher: name: arXiv
Year: 2013
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: Content-Centric Networking (CCN) is an emerging networking paradigm being considered as a possible replacement for the current IP-based host-centric Internet infrastructure. In CCN, named content becomes a first-class entity. CCN focuses on content distribution, which dominates current Internet traffic and is arguably not well served by IP. Named-Data Networking (NDN) is an example of CCN. NDN is also an active research project under the NSF Future Internet Architectures (FIA) program. FIA emphasizes security and privacy from the outset and by design. To be a viable Internet architecture, NDN must be resilient against current and emerging threats. This paper focuses on distributed denial-of-service (DDoS) attacks; in particular we address interest flooding, an attack that exploits key architectural features of NDN. We show that an adversary with limited resources can implement such attack, having a significant impact on network performance. We then introduce Poseidon: a framework for detecting and mitigating interest flooding attacks. Finally, we report on results of extensive simulations assessing proposed countermeasure.
description: The IEEE Conference on Local Computer Networks (LCN 2013)
Topological insulators and geometry of vector bundles
Creators: name: Sergeev, A. S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: For a long time, band theory of solids has focused on the energy spectrum, or Hamiltonian eigenvalues. Recently, it was realized that the collection of eigenvectors also contains important physical information. The local geometry of eigenspaces determines the electric polarization, while their global twisting gives rise to the metallic surface states in topological insulators. These phenomena are central topics of the present notes. The shape of eigenspaces is also responsible for many intriguing physical analogies, which have their roots in the theory of vector bundles. We give an informal introduction to the geometry and topology of vector bundles and describe various physical models from this mathematical perspective.
description: v2: revised and extended version, submission to SciPost
Constraints on the secular variation of Mercury's magnetic field from the combined analysis of MESSENGER and Mariner 10 data
Creators: name: Philpott, Lydia C.
name: Johnson, Catherine L.
name: Winslow, Reka M.
name: Anderson, Brian J.
name: Korth, Haje
name: Purucker, Michael E.
name: Solomon, Sean C.
Publisher: name: Columbia University
Year: 2014
Subjects: Planetary science
Cosmic magnetic fields
Geomagnetism--Secular variations

description: Observations of Mercury's internal magnetic field from the Magnetometer on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft have revealed a dipole moment of 190 nT R M3 offset about 480 km northward from the planetary equator, where R M is Mercury's radius. We have reanalyzed magnetic field observations acquired by the Mariner 10 spacecraft during its third flyby of Mercury (M10‐III) in 1975 to constrain the secular variation in the internal field over the past 40 years. With the application of techniques developed in the analysis of MESSENGER data, we find that the dipole moment that best fits the M10‐III data is 188 nT R M3 offset 475 km northward from the equator. Our results are consistent with no secular variation, although variations of up to 10%, 16%, and 35%, respectively, are permitted in the zonal coefficients g 10, g 20, and g 30 in a spherical harmonic expansion of the internal field.
title: Μελέτη γεωλογικών και γεωφυσικών δεδομένων της περιοχής Φραγκοκάστελλο, Ν. Χανίων
Creators: name: Χειμωνας Θεοδωρος
Publisher: name: Technical University of Crete
Year: 2015

description: Το Φραγκοκάστελλο είναι μεσαιωνικό κάστρο που χτίστηκε στο διάστημα 1371-74 από τους Βενετούς σε μια στενή παράκτια ζώνη στο νοτιοανατολικό τμήμα των Λευκών Όρεων, περίπου 12 χιλιόμετρα ανατολικά της Χώρας Σφακίων. Αυτό το τμήμα χαρακτηρίζεται από ένα έντονο μορφολογικό ανάγλυφο που η δημιουργία του καθορίστηκε από την κινητικότητα κανονικών ρηγμάτων με γενικές διευθύνσεις Α-Δ, ΒΒΑ-ΝΝΔ και ΒΒΔ-ΝΝΑ. Την περιοχή ενδιαφέροντος δομούν επιφανειακά ακολουθίες (κυρίως θαλάσσιες) του Τορτονίου, του Κάτω Πλειοκαίνου και του Κατώτερου Πλειστόκαινου. Από το Μέσο Πλειστόκαινο πολλαπλές συμφύσεις αλλουβιακών ριπιδίων κάλυψαν τόσο το αλπικό υπόβαθρο της ευρύτερης περιοχής που αποτελείται από τα μεταμορφωμένα πετρώματα της Ομάδας των Πλακωδών Ασβεστολίθων, της ενότητας Τρυπαλίου και της Φυλλιτικής Χαλαζιακής Σειράς καθώς και τους νεότερους σε ηλικία σχηματισμούς. Στρογγυλωμένα και γωνιώδη κλάσματα πετρωμάτων των αλπικών αλλά και μεταλπικών σχηματισμών που μεταφέρθηκαν και αποτέθηκαν εντός των διαφόρων τμημάτων των αλλουβιακών ριπιδίων αποτέλεσαν τους δομικούς λίθους για της κατασκευή του κάστρου. Το μικροκλίμα της περιοχής και η έντονη τεκτονική δραστηριότητα που σχετίζεται με σχετικά υψηλούς ρυθμούς ανύψωσης των ρηξιτεμαχών στην περιοχή, επηρέασαν καθοριστικά όχι μόνο την στατική του κάστρου αλλά και την αντοχή στην αποσάθρωση των δομικών του λίθων μετά την φυσική αποψίλωση μεγάλων τμημάτων του κονιάματος του εξωτερικού της τοιχοποιίας.
Με βάση τα ανωτέρω στόχος της εργασίας αυτής αποτέλεσε αρχικά η συλλογή βιβλιογραφικών δεδομένων σχετικών με την στρωματογραφία και τεκτονική της περιοχής. Ο συνδυασμός αυτών των δεδομένων με εργασίες πεδίου βοήθησε στην ερμηνεία των αποτελεσμάτων γεωφυσικής διασκόπησης που πραγματοποιήθηκε εντός και πέριξ του κάστρου, για τον καθορισμό κυρίως ζωνών ασυνεχειών του ανθρακικού στρώματος πάχους μερικών μέτρων, πάνω στο οποίο εδράζεται το κάστρο. Τα αποτελέσματα που προέκυψαν συνδυαζόμενα με τα αποτελέσματα από την καταμέτρηση και στατιστική επεξεργασία των διαφόρων λιθολογικών τύπων των δομικών υλικών του κάστρου μπορούν να αποτελέσουν δεδομένα εισαγωγής μοντέλων στατικότητας, στα πλαίσια των προτάσεων συντήρησης και αποκατάστασης του μνημείου.
Possible surface plasmon polariton excitation under femtosecond laser irradiation of silicon
Creators: name: Derrien, Thibault J. -Y.
name: Itina, Tatiana E.
name: Torres, Rémi
name: Sarnet, Thierry
name: Sentis, Marc
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Optics (physics.optics)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The mechanisms of ripple formation on silicon surface by femtosecond laser pulses are investigated. We demonstrate the transient evolution of the density of the excited free-carriers. As a result, the experimental conditions required for the excitation of surface plasmon polaritons are revealed. The periods of the resulting structures are then investigated as a function of laser parameters, such as the angle of incidence, laser fluence, and polarization. The obtained dependencies provide a way of better control over the properties of the periodic structures induced by femtosecond laser on the surface of a semiconductor material.
description: 11 pages, 8 figures, accepted for publication in Journal of Applied Physics
A Level-Set Immersed Boundary Method for Reactive Transport in Complex Topologies with Moving Interfaces
Creators: name: Yousefzadeh, Mehrdad
name: Yao, Yinuo
name: Battiato, Ilenia
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: A simulation framework based on the level-set and the immersed boundary methods (LS-IBM) has been developed for reactive transport problems in porous media involving a moving solid-fluid interface. The interface movement due to surface reactions is tracked by the level-set method, while the immersed boundary method captures the momentum and mass transport at the interface. The proposed method is capable of accurately modeling transport near evolving boundaries in Cartesian grids. The framework formulation guarantees second order accuracy in space. Since the interface velocity is only defined at the moving boundary, an interface velocity propagation method is also proposed. The method can be applied to other moving interface problems of the ``Stefan'' type. Here, we validate the proposed LS-IBM both for flow and transport close to an immersed object with reactive boundaries as well as for crystal growth. The proposed method provides a powerful tool to model more realistic problems involving moving reactive interfaces in complex domains.
description: 61 pages, 30 figures
Work fluctuations for diffusion dynamics submitted to stochastic return
Creators: name: Gupta, Deepak
name: Plata, Carlos A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Returning a system to a desired state under a force field involves a thermodynamic cost, i.e., {\it work}. This cost fluctuates for a small-scale system from one experimental realization to another. We introduce a general framework to determine the work distribution for returning a system facilitated by a confining potential with its minimum at the restart location. The general strategy, based on average over {\it resetting pathways}, constitutes a robust method to gain access to the statistical information of observables from resetting systems. We exploit paradigmatic setups, where explicit computations are attainable, to illustrate the theory. Numerical simulations validate our theoretical predictions. For some of these examples, a non-trivial behavior of the work fluctuations opens a door to optimization problems. Specifically, work fluctuations can be minimized by an appropriate tuning of the return rate.
description: 17 pages, 4 figures
How collaboration is instrumental at the University of Oslo to achieve goals related to research data management (RDM)
Creators: name: Fotland, Margaret Louise
name: Stangeland, Elin
name: Bergsaker, Anne
name: Rockenberger, Annika
Publisher: name: Zenodo
Year: 2021

description: At the University of Oslo, cross-departmental collaboration on strategic development and solutions development is critical to achieving progress in a time of limited resources and rapid change. The department of research administration, the university center for information technology and the university library currently collaborate and coordinate their activities in order to ensure best practices for research data management at the university. We acknowledge that collaboration across these groups is challenging. Examples of challenges are issues with language related to the different professions' terminologies; different cultures and priorities within fields (e.g. the IT department focuses on infrastructure, IT-security, and storage, while the library focuses on archiving and management, while the research office focuses on policy and legal matters). Why is it still beneficial to collaborate then? There are several answers to this. Firstly, we find that working together makes gaining impact within the institution easier. By making the case together, we can emphasize the importance of RDM both to university management and the researchers and departments. At the same time, we are able to ascertain what activities taking place across the collaborating departments are well-coordinated and can be joined up if necessary. By the time of the conference, we also aim to have established a cross-institutional network of research data support workers, providing a networking forum and, we hope, enabling knowledge exchange and cross-departmental collaboration across the institution. The latter is very important as the institution is facing cuts caused by the national de-bureaucratization reform and finding fresh resources to ascertain good RDM support is very difficult. In our presentation, we will talk more about the issues described above, share more of our experiences and also discuss some of our achievements with RDM so far.
Strong overall error analysis for the training of artificial neural networks via random initializations
Creators: name: Jentzen, Arnulf
name: Riekert, Adrian
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Numerical Analysis (math.NA)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Although deep learning based approximation algorithms have been applied very successfully to numerous problems, at the moment the reasons for their performance are not entirely understood from a mathematical point of view. Recently, estimates for the convergence of the overall error have been obtained in the situation of deep supervised learning, but with an extremely slow rate of convergence. In this note we partially improve on these estimates. More specifically, we show that the depth of the neural network only needs to increase much slower in order to obtain the same rate of approximation. The results hold in the case of an arbitrary stochastic optimization algorithm with i.i.d.\ random initializations.
description: 40 pages
title: Μελέτη συνθηκών ευστάθειας υπαίθριου μεταλλείου πορφυριτικού χαλκού-χρυσού
Creators: name: Κορδιστος Δημητριος
Publisher: name: Technical University of Crete
Year: 2015

description: Το φαινόμενο των αστoχιών πρανών είναι πολύ συχνό σε επιφανειακές εκμετάλλεύσεις κοιτασμάτων. Οι αστοχίες αυτές συνήθως προκαλούνται από προϋπάρχουσες ασυνέχειες πετρωμάτων και ρήγματα. Γι’ αυτό το λόγο είναι σημαντική η έγκαιρη και λεπτομερής αποτύπωση των ασυνεχειών πριν τον σχεδιασμό της εκμετάλλευσης αλλά και κατά την διάρκεια της εκμετάλλευσης. Η αποτύπωση των ασυνεχειών μπορεί να γίνει σε εκτεθειμένα μέτωπα ή καρότα πυρηνοληπτικών γεωτρήσεων. Η εν συνεχεία ανάλυση όλων των δεδομένων θα συντελέσει στον καλύτερο σχεδιασμό της εκμετάλλευσης για την ασφαλή και ομαλή λειτουργία του μεταλλείου.
Στην παρούσα διπλωματική εργασία αναλύονται καταρχήν δεδομένα προσανατολισμού ασυνεχειών από τρείς προσανατολισμένες γεωτρήσεις (Slos04,Slos06,Sopg147) στο νοτιο-δυτικό τμήμα της υπό σχεδιασμό εκμετάλλευσης κοιτάσματος χρυσού-χαλκού στις Σκουριές ΒΑ Χαλκιδικής. Με βάση την ανάλυση και  τη βοήθεια της στερεογραφικής προβολής αναλύθηκαν όλες οι πιθανές περιπτώσεις αστοχίας πρανών (ολίσθηση σε επίπεδο και σε σφήνα, ανατροπή) ανάλογα και με το σχεδιασμό των πρανών. Εν συνεχεία επεξεργάζονται τα τεχνικά και φυσικά χαρακτηριστικά των αποτυπωθέντων ασυνεχειών (η τραχύτητα, το υλικό πλήρωσης των ασυνεχειών, η ύπαρξη νερού κ.λπ.) στους πυρήνες και προσδιορίζεται ο δείκτης Q  του NGI ανά 5 m κατά μήκος των γεωτρήσεων. Κατόπιν προσδιορίζεται με εμπειρικό τρόπο η συνοχή και η γωνία τριβής των ασυνεχειών που είναι σημαντικές παράμετροι για τον τελικό σχεδιασμό των πρανών της εκμετάλλευσης.
Thickness of the crust of Mercury from geoid‐to‐topography ratios
Creators: name: Padovan, Sebastiano
name: Wieczorek, Mark A.
name: Margot, Jean-Luc
name: Tosi, Nicola
name: Solomon, Sean C.
Publisher: name: Columbia University
Year: 2015
Subjects: Planetary science
Planets--Mantles
Planets--Geology
Topographic maps

description: To gain insight into the thickness of the crust of Mercury, we use gravity and topography data acquired by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft to calculate geoid‐to‐topography ratios over the northern hemisphere of the planet. For an Airy model for isostatic compensation of variations in topography, we infer an average crustal thickness of 35 ± 18 km. Combined with the value of the radius of the core of Mercury, this crustal thickness implies that Mercury had the highest efficiency of crustal production among the terrestrial planets. From the measured abundance of heat‐producing elements on the surface, we calculate that the heat production in the mantle from long‐lived radioactive elements at 4.45 Ga was greater than 5.4 ×10−12W/kg. By analogy with the Moon, the relatively thin crust of Mercury allows for the possibility that major impact events, such as the one that formed the Caloris basin, excavated material from Mercury's mantle.
Bootstrapping traceless symmetric $O(N)$ scalars
Creators: name: Reehorst, Marten
name: Refinetti, Maria
name: Vichi, Alessandro
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We use numerical bootstrap techniques to study correlation functions of traceless symmetric tensors of $O(N)$ with two indexes $t_{ij}$. We obtain upper bounds on operator dimensions for all the relevant representations and several values of $N$. We discover several families of kinks, which do not correspond to any known model and we discuss possible candidates. We then specialize to the case $N=4$, which has been conjectured to describe a phase transition in the antiferromagnetic real projective model ARP$^{3}$. Lattice simulations provide strong evidence for the existence of a second order phase transition, while an effective field theory approach does not predict any fixed point. We identify a set of assumptions that constrain operator dimensions to a closed region overlapping with the lattice prediction. The region is still present after pushing the numerics in the single correlator case or when considering a mixed system involving $t$ and the lowest dimension scalar singlet.
description: 49 pages, 27 figures Fixed minor typos. Added a subsection on "External operator as the lowest dimensional operator of its kind". Included bounds using this additional assumption in figures 8a and 8b
Fast unified reconstruction algorithm for conventional, phase-contrast and diffraction tomography
Creators: name: Gureyev, Timur E.
name: Brown, Hamish G.
name: Quiney, Harry M.
name: Allen, Leslie J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Medical Physics (physics.med-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: A unified method for three-dimensional reconstruction of objects from transmission images collected at multiple illumination directions is described. The method may be applicable to experimental conditions relevant to absorption-based, phase-contrast or diffraction imaging using X-rays, electrons and other forms of penetrating radiation or matter waves. Both the phase retrieval (also known as contrast transfer function correction) and the effect of Ewald sphere curvature (in the cases with a shallow depth of field and significant in-object diffraction) are incorporated in the proposed algorithm and can be taken into account. Multiple scattering is not treated explicitly, but can be mitigated as a result of angular averaging that constitutes an essential feature of the method. The corresponding numerical algorithm is based on three-dimensional gridding which allows for fast computational implementation, including a straightforward parallelization. The algorithm can be used with any scanning geometry involving plane-wave illumination. A software code implementing the proposed algorithm has been developed, tested on simulated and experimental image data and made publicly available.
description: 16 pages, 3 figures
Dual Adaptive Representation Alignment for Cross-domain Few-shot Learning
Creators: name: Zhao, Yifan
name: Zhang, Tong
name: Li, Jia
name: Tian, Yonghong
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Few-shot learning aims to recognize novel queries with limited support samples by learning from base knowledge. Recent progress in this setting assumes that the base knowledge and novel query samples are distributed in the same domains, which are usually infeasible for realistic applications. Toward this issue, we propose to address the cross-domain few-shot learning problem where only extremely few samples are available in target domains. Under this realistic setting, we focus on the fast adaptation capability of meta-learners by proposing an effective dual adaptive representation alignment approach. In our approach, a prototypical feature alignment is first proposed to recalibrate support instances as prototypes and reproject these prototypes with a differentiable closed-form solution. Therefore feature spaces of learned knowledge can be adaptively transformed to query spaces by the cross-instance and cross-prototype relations. Besides the feature alignment, we further present a normalized distribution alignment module, which exploits prior statistics of query samples for solving the covariant shifts among the support and query samples. With these two modules, a progressive meta-learning framework is constructed to perform the fast adaptation with extremely few-shot samples while maintaining its generalization capabilities. Experimental evidence demonstrates our approach achieves new state-of-the-art results on 4 CDFSL benchmarks and 4 fine-grained cross-domain benchmarks.
description: 13 pages; Accepted by IEEE T-PAMI
Uniform asymptotic approximation of diffusion to a small target
Creators: name: Isaacson, Samuel A.
name: Newby, Jay
Publisher: name: arXiv
Year: 2013
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The problem of the time required for a diffusing molecule, within a large bounded domain, to first locate a small target is prevalent in biological modeling. Here we study this problem for a small spherical target. We develop uniform in time asymptotic expansions in the target radius of the solution to the corresponding diffusion equation. Our approach is based on combining short-time expansions using pseudo-potential approximations with long-time expansions based on first eigenvalue and eigenfunction approximations. These expansions allow the calculation of corresponding expansions of the first passage time density for the diffusing molecule to find the target. We demonstrate the accuracy of our method in approximating the first passage time density and related statistics for the spherically symmetric problem where the domain is a large concentric sphere about a small target centered at the origin.
description: 15 pages, 7 figures
Inferring oscillator's phase and amplitude response from a scalar signal exploiting test stimulation
Creators: name: Cestnik, Rok
name: Mau, Erik T. K.
name: Rosenblum, Michael
Publisher: name: arXiv
Year: 2022
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Physical sciences

description: The phase sensitivity curve or phase response curve (PRC) quantifies the oscillator's reaction to stimulation at a specific phase and is a primary characteristic of a self-sustained oscillatory unit. Knowledge of this curve yields a phase dynamics description of the oscillator for arbitrary weak forcing. Similar, though much less studied characteristic, is the amplitude response that can be defined either using an ad hoc approach to amplitude estimation or via the isostable variables. Here, we discuss the problem of the phase and amplitude response inference from observations using test stimulation. Although PRC determination for noise-free neuronal-like oscillators perturbed by narrow pulses is a well-known task, the general case remains a challenging problem. Even more challenging is the inference of the amplitude response. This characteristic is crucial, e.g., for controlling the amplitude of the collective mode in a network of interacting units -- a task relevant to neuroscience. Here, we compare the performance of different techniques suitable for inferring the phase and amplitude response, particularly with application to macroscopic oscillators. We suggest improvements to these techniques, e.g., demonstrating how to obtain the PRC in case of stimuli of arbitrary shape. Our main result is a novel technique denoted by IPID-1, based on the direct reconstruction of the Winfree equation and the analogous first-order equation for isostable dynamics. The technique works for signals with or without well-pronounced marker events and pulses of arbitrary shape; in particular, we consider charge-balanced pulses typical in neuroscience applications. Moreover, this technique is superior for noisy and high-dimensional systems. Additionally, we describe an error measure that can be computed solely from data and complements any inference technique.
description: 27 pages, 15 figures; proofread, published version
title: Παραμετρική διερεύνηση καννάβων ανατίναξης σε υπόγειες εκμεταλλεύσεις βωξιτικών κοιτασμάτων
Creators: name: Στυλιαρης Λουκας
Publisher: name: Technical University of Crete
Year: 2015

description: Στην διπλωματική αυτή εργασία πραγματοποιείται μια σύγκριση της απόδοσης δύο εκρηκτικών, της ζελατοδυναμίτιδας και του γαλακτώματος όταν αυτά χρησιμοποιούνται για την εξόρυξη ασβεστολίθου και βωξίτη σε υπόγειες εκμεταλλεύσεις. Η σύγκριση γίνεται για να προσδιοριστεί πιο εκρηκτικό μπορεί να θεωρηθεί πιο αποδοτικό κατά την εξόρυξη των δύο αυτών πετρωμάτων.
Για την μελέτη αυτή χρησιμοποιήθηκαν μετρήσεις από ανατινάξεις από μία παραγωγική στοά βωξίτη. Το μετρούμενο μέγεθος ήταν ο παραγόμενος όγκος, η προχώρηση σε μέτρα αλλά και η ποσότητα των εκρηκτικών. Η ποιότητα της κάθε ανατίναξης αξιολογήθηκε σε κλίμακα από 1-10.
Από την επεξεργασία των δεδομένων προκύπτουν ενδιαφέροντα συμπεράσματα σχετικά με την απόδοση του κάθε εκρηκτικού ενώ προτείνονται μέτρα για την βελτιστοποίηση της διαδικασίας.
Resonant tunneling diodes in semiconductor microcavities: modeling polaritonic features in the THz displacement current
Creators: name: Destefani, Carlos F.
name: Villani, Matteo
name: Cartoixà, Xavier
name: Feiginov, Michael
name: Oriols, Xavier
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Applied Physics (physics.app-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We develop in this work a simple qualitative quantum electron transport model, in the strong light-matter coupling regime under dipole approximation, able to capture polaritonic signatures in the time-dependent electrical current. The effect of the quantized electromagnetic field in the displacement current of a resonant tunneling diode inside an optical cavity is analyzed. The original peaks of the bare electron transmission coefficient split into two new peaks due to the resonant electron-photon interaction, leading to coherent Rabi oscillations among the polaritonic states that are developed in the system in the strong coupling regime. This mimics known effects predicted by a Jaynes-Cummings model in closed systems, and shows how a full quantum treatment of electrons and electromagnetic fields may open interesting paths for engineering new THz electron devices. The computational burden involved in the multi-time measurements of THz currents is tackled by invoking a Bohmian description of the light-matter interaction. We also show that the traditional static transmission coefficient used to characterize DC quantum electron devices has to be substituted by a new displacement current coefficient in high-frequency AC scenarios.
description: 26 pages, 8 figures
Matrix products of binomial coefficients and unsigned Stirling numbers
Creators: name: Knežević, Marin
name: Krčadinac, Vedran
name: Relić, Lucija
Publisher: name: arXiv
Year: 2020
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05A10

description: We study sums of the form $\sum_{k=m}^n a_{nk} b_{km}$, where $a_{nk}$ and $b_{km}$ are binomial coefficients or unsigned Stirling numbers. In a few cases they can be written in closed form. Failing that, the sums still share many common features: combinatorial interpretations, Pascal-like recurrences, inverse relations with their signed versions, and interpretations as coefficients of change between polynomial bases.
description: 10 pages
The more things change the more they stay the same: Minimum lengths with unmodified uncertainty principle and dispersion relation
Creators: name: Bishop, Michael
name: Contreras, Joey
name: Singleton, Douglas
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Broad arguments indicate that quantum gravity should have a minimal length scale. In this essay we construct a minimum length model by generalizing the time-position and energy-momentum operators while keeping much of the structure of quantum mechanics and relativity intact: the standard position-momentum commutator, the special relativistic time-position, and energy-momentum relationships all remain the same. Since the time-position and energy-momentum relationships for the modified operators remains the same, we retain a form of Lorentz symmetry. This avoids the constraints on these theories coming from lack of photon dispersion while holding the potential to address the Greisen-Zatsepin-Kuzmin (GZK) puzzle of ultra high energy cosmic rays.
description: 10 pages, 2 figures, revtex4. 2nd place award for the 2022 Gravity Research Foundation essay competition. To be published IJMPD
Quantum Skew Divergence
Creators: name: Audenaert, Koenraad M. R.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In this paper we study the quantum generalisation of the skew divergence, which is a dissimilarity measure between distributions introduced by L. Lee in the context of natural language processing. We provide an in-depth study of the quantum skew divergence, including its relation to other state distinguishability measures. Finally, we present a number of important applications: new continuity inequalities for the quantum Jensen-Shannon divergence and the Holevo information, and a new and short proof of Bravyi's Small Incremental Mixing conjecture.
description: Supersedes 1102:3041, as it contains many new results and applications. v2: minor modifications, including a streamlining of the proofs. 32 1/4 pages
Research participants' views: ethical guidelines for archiving and sharing stories of migration for future reuse
Creators: name: Van Den Eynden, Veerle
name: Haaker, Maureen
Publisher: name: Zenodo
Year: 2021

description: In the last five years, research funders in the UK have funded much social science research into the global migration crisis. This research explores intimate, and often difficult, aspects of migrant lives and creates a historically significant record of the testimonies of refugees. Despite data policies and data management plans showing intentions to archive these data, the ethical challenges meant very little of the data ended up preserved in an archive. It is well-known that sharing and archiving qualitative research data poses ethical challenges, especially with vulnerable participants and sensitive topics. Personal stories told may be impossible to anonymise. Research participants from different cultural backgrounds may have a different understanding of ethical principles and consent, with researchers uncertain how best to approach this. At the same time, such qualitative research data provide valuable evidence and often unique resources for future research and policy making. And also vulnerable research participants may want their voices heard beyond the primary research. We will present findings and practical guidelines resulting from a seminar and follow-up discussions, where we brought different stakeholders together: historians reusing past migration stories, migration researchers, research participants, national and grass-roots organisations working with migrants and refugees and providing advocacy. Discussions looked at ownership and stewardship of migration stories, how researchers engage with participants, participants as equitable partners rather than vulnerable subjects, participatory and citizen science approaches to collecting and preserving knowledge and stories.