cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Local Fourier analysis of multigrid for hybridized and embedded discontinuous Galerkin methods
Creators: name: He, Yunhui
name: Rhebergen, Sander
name: De Sterck, Hans
Publisher: name: arXiv
Year: 2020
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: In this paper we present a geometric multigrid method with Jacobi and Vanka relaxation for hybridized and embedded discontinuous Galerkin discretizations of the Laplacian. We present a local Fourier analysis (LFA) of the two-grid error-propagation operator and show that the multigrid method applied to an embedded discontinuous Galerkin (EDG) discretization is almost as efficient as when applied to a continuous Galerkin discretization. We furthermore show that multigrid applied to an EDG discretization outperforms multigrid applied to a hybridized discontinuous Galerkin (HDG) discretization. Numerical examples verify our LFA predictions.
Resonant orbits of rotating black holes beyond circularity: Discontinuity along parameter shift
Creators: name: Chen, Che-Yu
name: Chiang, Hsu-Wen
name: Patel, Avani
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: According to general relativity, an isolated black hole in vacuum shall be described by the Kerr metric, whose geodesic equations are integrable. The violation of integrability leads to chaos for particles moving around the black hole. This chaotic dynamics could leave imprints on the associated gravitational waveform and could be tested with upcoming observations. In this paper, we investigate the chaotic orbital dynamics induced by the violation of a certain spacetime symmetry, the circularity. Specifically, we focus on the resonant orbits of a particular noncircular spacetime as an example and find that they form chains of Birkhoff islands on Poincaré surfaces of section. We compare the island structures with those generated in typical nonintegrable but circular spacetimes. The islands of stability induced by noncircularity appear asymmetric on the most common Poincaré surface of section at the equatorial plane. The asymmetric patterns of islands vary discontinuously when the spacetime parameters transit through integrable regions. The origin of such features is explained in the context of perturbation analysis by considering the orbits associated with stable fixed points on the section. Possible observational implications about testing circularity through gravitational wave detection are discussed.
description: 15 pages, 9 figures, Matches with published version
Deformations and embeddings of three-dimensional strictly pseudoconvex CR manifolds
Creators: name: Curry, Sean N.
name: Ebenfelt, Peter
Publisher: name: arXiv
Year: 2020
Subjects: subject: Complex Variables (math.CV)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 32G07, 32V30, 32V20

description: Abstract deformations of the CR structure of a compact strictly pseudoconvex hypersurface $M$ in $\mathbb{C}^2$ are encoded by complex functions on $M$. In sharp contrast with the higher dimensional case, the natural integrability condition for $3$-dimensional CR structures is vacuous, and generic deformations of a compact strictly pseudoconvex hypersurface $M\subseteq \mathbb{C}^2$ are not embeddable even in $\mathbb{C}^N$ for any $N$. A fundamental (and difficult) problem is to characterize when a complex function on $M \subseteq \mathbb{C}^2$ gives rise to an actual deformation of $M$ inside $\mathbb{C}^2$. In this paper we study the embeddability of families of deformations of a given embedded CR $3$-manifold, and the structure of the space of embeddable CR structures on $S^3$. We show that the space of embeddable deformations of the standard CR $3$-sphere is a Frechet submanifold of $C^{\infty}(S^3,\mathbb{C})$ near the origin. We establish a modified version of the Cheng-Lee slice theorem in which we are able to characterize precisely the embeddable deformations in the slice (in terms of spherical harmonics). We also introduce a canonical family of embeddable deformations and corresponding embeddings starting with any infinitesimally embeddable deformation of the unit sphere in $\mathbb{C}^2$.
description: 46 pages. Accepted version. Math. Ann. (2023). Section 3 has been substantially revised to streamline the presentation; a detailed proof of Theorem 3.1 was also added. Section 4.5 has been expanded and clarified. Some inconsistencies of signs and factors of 2 were fixed in Sections 2 and 3
An Efficient and Robust Social Network De-anonymization Attack
Creators: name: Gulyás, Gábor György
name: Simon, Benedek
name: Imre, Sándor
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cryptography and Security (cs.CR)
subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: Releasing connection data from social networking services can pose a significant threat to user privacy. In our work, we consider structural social network de-anonymization attacks, which are used when a malicious party uses connections in a public or other identified network to re-identify users in an anonymized social network release that he obtained previously. In this paper we design and evaluate a novel social de-anonymization attack. In particular, we argue that the similarity function used to re-identify nodes is a key component of such attacks, and we design a novel measure tailored for social networks. We incorporate this measure in an attack called Bumblebee. We evaluate Bumblebee in depth, and show that it significantly outperforms the state-of-the-art, for example it has higher re-identification rates with high precision, robustness against noise, and also has better error control.
Efficient single photon emission from a high-purity hexagonal boron nitride crystal
Creators: name: Martínez, L. J.
name: Pelini, T.
name: Waselowski, V.
name: Maze, J. R.
name: Gil, B.
name: Cassabois, G.
name: Jacques, V.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Among a variety of layered materials used as building blocks in van der Waals heterostructures, hexagonal boron nitride (hBN) appears as an ideal platform for hosting optically-active defects owing to its large bandgap ($\sim 6$ eV). Here we study the optical response of a high-purity hBN crystal under green laser illumination. By means of photon correlation measurements, we identify individual defects emitting a highly photostable fluorescence under ambient conditions. A detailed analysis of the photophysical properties reveals a high quantum efficiency of the radiative transition, leading to a single photon source with very high brightness. These results illustrate how the wide range of applications offered by hBN could be further extended to photonic-based quantum information science and metrology.
description: 5 pages, 4 figures
Solvable BCS-Hubbard Liouvillians in arbitrary dimensions
Creators: name: Dai, Xu-Dong
name: Song, Fei
name: Wang, Zhong
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We present the construction of a solvable Lindblad model in arbitrary dimensions, wherein the Liouvillian can be mapped to a BCS-Hubbard model featuring an imaginary interaction. The Hilbert space of the system can be divided into multiple sectors, each characterized by an onsite invariant configuration. The model exhibits bistable steady states in all spatial dimensions, which is guaranteed by the fermion-number parity. Notably, the Liouvillian gap exhibits a Zeno transition, below which the Liouvillian gap is linear with respect to the dissipation. We also uncover a generic dimension-dependent gap behavior: In one dimension, the gap originates from multiple sectors with spectral crossing; in higher dimensions, a single sector determines the gap.
description: 7 pages, 2 figures
Decoding NGC 7252 as a blue elliptical galaxy
Creators: name: George, Koshy
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Elliptical galaxies with blue optical colours and significant star formation are hypothesised to be major merger remnants of gas-rich spiral galaxies or normal elliptical galaxies with a sudden burst of star formation. We present here a scenario in which blue elliptical galaxies identified in shallow imaging surveys may fail to recover faint features that are indicative of past merger activity using a nearby major merger remnant. Based on deep optical imaging data of the post-merger galaxy, NGC 7252, we demonstrate that the galaxy can appear as an elliptical galaxy if it is observed at higher redshifts. The main body and the low surface brightness merger features found at the outskirts of the galaxy are blue in the optical g - r colour map. We argue that the higher-redshift blue elliptical galaxies discovered in surveys as shallow as the SDSS or DECaLS may be advanced mergers whose defining tidal features fall below the detection limits of the surveys. This should be taken into consideration during the morphological classification of these systems in future and ongoing surveys.
description: Accepted for publication in A&A
Hedging using reinforcement learning: Contextual $k$-Armed Bandit versus $Q$-learning
Creators: name: Cannelli, Loris
name: Nuti, Giuseppe
name: Sala, Marzio
name: Szehr, Oleg
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Computational Finance (q-fin.CP)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences
subject: FOS: Economics and business

description: The construction of replication strategies for contingent claims in the presence of risk and market friction is a key problem of financial engineering. In real markets, continuous replication, such as in the model of Black, Scholes and Merton (BSM), is not only unrealistic but it is also undesirable due to high transaction costs. A variety of methods have been proposed to balance between effective replication and losses in the incomplete market setting. With the rise of Artificial Intelligence (AI), AI-based hedgers have attracted considerable interest, where particular attention was given to Recurrent Neural Network systems and variations of the $Q$-learning algorithm. From a practical point of view, sufficient samples for training such an AI can only be obtained from a simulator of the market environment. Yet if an agent was trained solely on simulated data, the run-time performance will primarily reflect the accuracy of the simulation, which leads to the classical problem of model choice and calibration. In this article, the hedging problem is viewed as an instance of a risk-averse contextual $k$-armed bandit problem, which is motivated by the simplicity and sample-efficiency of the architecture. This allows for realistic online model updates from real-world data. We find that the $k$-armed bandit model naturally fits to the Profit and Loss formulation of hedging, providing for a more accurate and sample efficient approach than $Q$-learning and reducing to the Black-Scholes model in the absence of transaction costs and risks.
description: 30 pages, 11 figures
Holographic realization from inflation to reheating in generalized entropic cosmology
Creators: name: Odintsov, Sergei D.
name: D'Onofrio, Simone
name: Paul, Tanmoy
Publisher: name: arXiv
Year: 2023
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: The growing cosmological interest of different entropy functions (like the Tsallis entropy, the Rényi entropy, the Barrow entropy, the Sharma-Mittal entropy, the Kaniadakis entropy and the Loop Quantum gravity entropy) naturally raises an important question: "Does there exist a generalized entropy that can bring all the known entropies proposed so far within a single umbrella?" In spirit of this, recently a four parameter generalized entropy has been formulated that reduces to different known entropies for suitable limits of the parameters. Based on such four parameter generalized entropy (symbolized by $S_\mathrm{g}$), in the present paper, we examine the universe's evolution during its early phase, particularly from inflation to reheating, in the context of entropic cosmology where the entropic energy density acts as the inflaton. It turns out that the entropic energy successfully drives an early inflationary phase with a graceful exit, and moreover, the theoretical expectations of the observable indices get consistent with the recent Planck data for suitable ranges of the entropic parameters. After the inflation ends, the universe enters to a reheating stage when the entropic energy decays to relativistic particles with a certain decay rate. Actually the presence of the entropic parameters in the $S_\mathrm{g}$ ensures a continuous evolution of the Hubble parameter from a quasi de-Sitter phase during the inflation to a power law phase during the reheating stage dominated by a constant EoS parameter. Consequently we investigate the reheating phenomenology, and scan the entropic parameters from both the inflation and reheating requirements. We further address the possibility of instantaneous reheating in the present context of generalized entropy.
description: "Physics of the Dark Universe" Accepted
A compatible embedded-hybridized discontinuous Galerkin method for the Stokes--Darcy-transport problem
Creators: name: Cesmelioglu, Aycil
name: Rhebergen, Sander
Publisher: name: arXiv
Year: 2020
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: We present a stability and error analysis of an embedded-hybridized discontinuous Galerkin (EDG-HDG) finite element method for coupled Stokes--Darcy flow and transport. The flow problem, governed by the Stokes--Darcy equations, is discretized by a recently introduced exactly mass conserving EDG-HDG method while an embedded discontinuous Galerkin (EDG) method is used to discretize the transport equation. We show that the coupled flow and transport discretization is compatible and stable. Furthermore, we show existence and uniqueness of the semi-discrete transport problem and develop optimal a priori error estimates. We provide numerical examples illustrating the theoretical results. In particular, we compare the compatible EDG-HDG discretization to a discretization of the coupled Stokes--Darcy and transport problem that is not compatible. We demonstrate that where the incompatible discretization may result in spurious oscillations in the solution to the transport problem, the compatible discretization is free of oscillations. An additional numerical example with realistic parameters is also presented.
Feature Selection: A perspective on inter-attribute cooperation
Creators: name: Sosa-Cabrera, Gustavo
name: Gómez-Guerrero, Santiago
name: García-Torres, Miguel
name: Schaerer, Christian E.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: High-dimensional datasets depict a challenge for learning tasks in data mining and machine learning. Feature selection is an effective technique in dealing with dimensionality reduction. It is often an essential data processing step prior to applying a learning algorithm. Over the decades, filter feature selection methods have evolved from simple univariate relevance ranking algorithms to more sophisticated relevance-redundancy trade-offs and to multivariate dependencies-based approaches in recent years. This tendency to capture multivariate dependence aims at obtaining unique information about the class from the intercooperation among features. This paper presents a comprehensive survey of the state-of-the-art work on filter feature selection methods assisted by feature intercooperation, and summarizes the contributions of different approaches found in the literature. Furthermore, current issues and challenges are introduced to identify promising future research and development.
description: This preprint has not undergone peer review or any post-submission improvements or corrections. The Version of Record of this article is published in International Journal of Data Science and Analytics, and is available online at https://doi.org/10.1007/s41060-023-00439-z
Field emitter electrostatics: efficient improved simulation technique for highly precise calculation of field enhancement factors
Creators: name: Dall'Agnol, Fernando F.
name: de Assis, Thiago A.
name: Forbes, Richard G.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: When solving the Laplace equation numerically via computer simulation, in order to determine the field values at the surface of a shape model that represents a field emitter, it is necessary to define a simulation box and, within this, a simulation domain. This domain must not be so small that the box boundaries have an undesirable influence on the predicted field values. A recent paper discussed the situation of cylindrically symmetric emitter models that stand on one of a pair of well-separated parallel plates. This geometry can be simulated by using two-dimensional domains. For a cylindrical simulation box, formulae have previously been presented that define the minimum domain dimensions (MDD) (height and radius) needed to evaluate the apex value of the field enhancement factor for this type of model, with an error-magnitude never larger than a "tolerance" $ε_{\rm{tol}}$. This MDD criterion helps to avoid inadvertent errors and oversized domains. The present article discusses (in greater depth than previously) a significant improvement in the MDD method; this improvement has been called the MDD Extrapolation Technique (MDDET). By carrying out two simulations with relatively small MDD values, it is possible to achieve a level of precision comparable with the results of carrying out a single simulation using a much larger simulation domain. For some simulations, this could result in significant savings of memory requirements and computing time. Following a brief restatement of the original MDD method, the MDDET method is illustrated by applying it to the hemiellipsoid-on-plane (HEP) and hemisphere-on-cylindrical-post (HCP) emitter shape models.
description: 9 pages, 4 figures. Accepted for publication in JVSTB
An arbiter PUF secured by remote random reconfigurations of an FPGA
Creators: name: Spenke, Alexander
name: Breithaupt, Ralph
name: Plaga, Rainer
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: We present a practical and highly secure method for the authentication of chips based on a new concept for implementing strong Physical Unclonable Function (PUF) on field programmable gate arrays (FPGA). Its qualitatively novel feature is a remote reconfiguration in which the delay stages of the PUF are arranged to a random pattern within a subset of the FPGA's gates. Before the reconfiguration is performed during authentication the PUF simply does not exist. Hence even if an attacker has the chip under control previously she can gain no useful information about the PUF. This feature, together with a strict renunciation of any error correction and challenge selection criteria that depend on individual properties of the PUF that goes into the field make our strong PUF construction immune to all machine learning attacks presented in the literature. More sophisticated attacks on our strong-PUF construction will be difficult, because they require the attacker to learn or directly measure the properties of the complete FPGA. A fully functional reference implementation for a secure "chip biometrics" is presented. We remotely configure ten 64-stage arbiter PUFs out of 1428 lookup tables within a time of 25 seconds and then receive one "fingerprint" from each PUF within 1 msec.
Setting an upper limit for the total TeV neutrino flux from the disk of our Galaxy
Creators: name: Vecchiotti, Vittoria
name: Villante, Francesco L.
name: Pagliaroli, Giulia
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We set an upper limit for the total TeV neutrino flux expected from the disk of our Galaxy in the region $|l|<30^{\circ}$ and $|b|<2^{\circ}$ probed by the ANTARES experiment. We include both the diffuse emission, due to the interaction of cosmic rays with the interstellar medium, and the possible contribution produced by gamma-ray Galactic sources. The neutrino diffuse emission is calculated under different assumptions for the cosmic ray spatial and energy distribution in our Galaxy. In particular, we assume that the total gamma-ray flux produced by all the sources, resolved and unresolved by H.E.S.S., is produced via hadronic interaction and, hence, is coupled with neutrino emission. We compare our total neutrino flux with the recent ANTARES measurement of the neutrino from the Galactic Ridge. We show that the ANTARES best-fit flux requires the existence of a large source component, close to or even larger than the most optimistic predictions obtained with our approach.
Exponential mixing of frame flows for geometrically finite hyperbolic manifolds
Creators: name: Li, Jialun
name: Pan, Wenyu
name: Sarkar, Pratyush
Publisher: name: arXiv
Year: 2023
Subjects: subject: Dynamical Systems (math.DS)
subject: Differential Geometry (math.DG)
subject: Spectral Theory (math.SP)
subject: FOS: Mathematics
subject: 37D40, 22E40, 37A25, 37C30

description: As a final work to establish that frame flows for geometrically finite hyperbolic manifolds of arbitrary dimensions are exponentially mixing with respect to the Bowen-Margulis-Sullivan measure, this paper focuses on the case with cusps. To prove this, we utilize the countably infinite symbolic coding of the geodesic flow of Li-Pan and perform a frame flow version of Dolgopyat's method à la Sarkar-Winter and Tsujii-Zhang. This requires the local non-integrability condition and the non-concentration property but the challenge in the presence of cusps is that the latter holds only on a large proper subset of the limit set. To overcome this, we use a large deviation property for symbolic recurrence to the large subset. It is proved by studying the combinatorics of cusp excursions and using an effective renewal theorem as in the work of Li; the latter uses the exponential decay of the transfer operators for the geodesic flow of Li-Pan.
description: 62 pages, 8 figures
A study of unplanned absence amongst continuous shift workers in an Australian manufacturing company
Creators: name: Walton, Geoffrey Norman.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Scientific communities management in OpenEBench
Creators: name: Fernández, Jose M
name: Codó, Laia
name: Sundesha, Vicky
name: Garrayo, Javier
name: Gelpí, Josep Ll
name: Capella-Gutierrez, Salvador
Publisher: name: F1000 Research Limited
Year: 2020

description: OpenEBench (http://openebench.bsc.es) is the ELIXIR benchmarking and technical monitoring platform for bioinformatic tools, web servers and workflows. The infrastructure provides the resources to enable an objective, reproducible and unbiased comparison of bioinformatic software through metrics-based critical measurements on technical and scientific performance. Software developers are able to evaluate their tools against predefined reference datasets related to their scientific communities in organized scientific challenge events, and the computed metrics are compiled, analysed and publicly exposed.

Scientific communities involvement are essential for having real benchmarking activities, as they promote collaboration, transparency and harmonised standards. OpenEBench aims to support them by offering a flexible and well-established framework from which to administer and operate evaluation events for specific research domains. Community managers are trusted users, as they act as representatives for these communities. Community managers are responsible for, first, designing and developing evaluation workflows and, second, framing them into scientific benchmarking challenges following the agreements reached by their respective communities. In OpenEBench, the benchmarking evaluation workflows depend on a set of software containers which validate and evaluate the results of the bioinformatics methods under assessment by computing community-agreed performance metrics. Thus, community managers are able to integrate those evaluation workflows into the OEB Virtual Research Environment (http://openebench.bsc.es/vre) following an interactive web-based procedure whose main input are the software container-building recipes.

Importantly, communities control the publication life cycle of the benchmarking challenges by which evaluation workflows are made available on the platform. In similar terms, community managers also provide different reference datasets, under public or private terms, associated with each challenge. Reference datasets are used as input for participants to generate their predictions and as golden reference when evaluating participants input data.

Community managers are an essential figure for incorporating scientific communities into OpenEBench and maintaining its activities up-to-date once the community is integrated into the platform. Thus, OpenEBench strives to provide easy-to-use tools and mechanisms to these privileged users as part of the interactions with its communities.
Projective and Whittaker functors on category $\mathcal{O}$
Creators: name: Arias, Juan Camilo
name: Backelin, Erik
Publisher: name: arXiv
Year: 2020
Subjects: subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: F.2.2
subject: Primary 16G10, 16G70, 18G99

description: We show that the Whittaker functor on a regular block of the BGG-category $\mathcal{O}$ of a semisimple complex Lie algebra can be obtained by composing a translation to the wall functor with Soergel and Miličić's equivalence between the category of Whittaker modules and a singular block of $\mathcal{O}$. We show that the Whittaker functor is a quotient functor that commutes with all projective functors and endomorphisms between them.
description: 14 pages
On the Ribosomal Density that Maximizes Protein Translation Rate
Creators: name: Zarai, Yoram
name: Margaliot, Michael
name: Tuller, Tamir
Publisher: name: arXiv
Year: 2016
Subjects: subject: Genomics (q-bio.GN)
subject: FOS: Biological sciences

description: During mRNA translation, several ribosomes attach to the same mRNA molecule simultaneously translating it into a protein. This pipelining increases the protein production rate. A natural and important question is what ribosomal density maximizes the protein production rate. Using mathematical models of ribosome flow along both a linear and a circular mRNA molecule we prove that typically the steady-state production rate is maximized when the ribosomal density is one half of the maximal possible density. We discuss the implications of our results to endogenous genes under natural cellular conditions and also to synthetic biology.
Controlled non-autonomous matter-wave solitons in spinor Bose-Einstein condensates with spatiotemporal modulation
Creators: name: Ding, Cui-Cui
name: Zhou, Qin
name: Xu, Si-Liu
name: Sun, Yun-Zhou
name: Liu, Wen-Jun
name: Mihalache, Dumitru
name: Malomed, Boris A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: To study controlled evolution of non-autonomous matter-wave solitons in spinor Bose-Einstein condensates with spatiotemporal modulation, we focus on a system of three coupled Gross-Pitaevskii (GP) equations with space-time-dependent external potentials and temporally modulated gain/loss distributions. An integrability condition and a non-isospectral Lax pair for the coupled GP equations are obtained. Using it, we derive an infinite set of dynamical invariants, the first two of which are the mass and momentum. The Darboux transform is used to generate one- and two-soliton solutions. Under the action of different external potentials and gain/loss distributions, various solutions for controlled non-autonomous matter-wave solitons of both ferromagnetic and polar types are obtained, such as self-compressed, snake-like and stepwise solitons, and as well as breathers. In particular, the formation of states resembling rogue waves, under the action of a sign-reversible gain-loss distribution, is demonstrated too. Shape-preserving and changing interactions between two non-autonomous matter-wave solitons and bound states of solitons are addressed too. In this context, spin switching arises in the polar-ferromagnetic interaction. Stability of the non-autonomous matter-wave solitons is verified by means of systematic simulations of their perturbed evolution.
description: to be published in Chaos, Solitons & Fractals
Holographic description of $F(R)$ gravity coupled with Axion Dark Matter
Creators: name: D'Onofrio, Simone
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this work we study the autonomous dynamical system of different $F(R)$ models in the formalism of holographic dark energy using the generalized Nojiri-Odintsov cut-off. We explicitly give the expression of the fixed points as functions of the infrared cut-off for vacuum $F(R)$ gravity in flat and non-flat FRW background and for $F(R)$ coupling axion dark matter. Each fixed point component can be taken as a condition on the cut-off and on the expression of $F(R)$, leading to physically interesting constraints on these functions.
description: "International Journal of Geometric Methods in Modern Physics" Accepted
Logistic wavelets and logistic function: An application to model the spread of SARS-CoV-2 virus infections
Creators: name: Rzadkowski, Grzegorz
Publisher: name: arXiv
Year: 2020
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences
subject: 92D30, 65T60, 11B83

description: In the present paper, we model the cumulative number of persons reported to be infected by the SARS-CoV-2 virus, in a country or a region, by a sum of logistic functions. For a given logistic function, using Eulerian numbers, we find the zeros of its successive derivatives and their relationship with the saturation level of this function. In a given time series, having potentially the logistic trend, we use its second differences to determine points corresponding to these zeros. To estimate the parameters of the approximating logistic function, we define and use logistic wavelets. Then we apply the theory to the cases of SARS-CoV-2 infections in the United States and the United Kingdom.
description: 11 pages, 5 figures
AIR algebraic multigrid for a space-time hybridizable discontinuous Galerkin discretization of advection(-diffusion)
Creators: name: Sivas, Abdullah A.
name: Southworth, Ben S.
name: Rhebergen, Sander
Publisher: name: arXiv
Year: 2020
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65F08, 65F10, 65M22, 65M55, 65M60

description: This paper investigates the efficiency, robustness, and scalability of approximate ideal restriction (AIR) algebraic multigrid as a preconditioner in the all-at-once solution of a space-time hybridizable discontinuous Galerkin (HDG) discretization of advection-dominated flows. The motivation for this study is that the time-dependent advection-diffusion equation can be seen as a "steady" advection-diffusion problem in $(d+1)$-dimensions and AIR has been shown to be a robust solver for steady advection-dominated problems. Numerical examples demonstrate the effectiveness of AIR as a preconditioner for advection-diffusion problems on fixed and time-dependent domains, using both slab-by-slab and all-at-once space-time discretizations, and in the context of uniform and space-time adaptive mesh refinement. A closer look at the geometric coarsening structure that arises in AIR also explains why AIR can provide robust, scalable space-time convergence on advective and hyperbolic problems, while most multilevel parallel-in-time schemes struggle with such problems.
Planning and strategic aspects of merger and acquisition
Creators: name: Thorn, Colin Leslie.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Equilibration of a strongly interacting plasma: holographic analysis of local and nonlocal probes
Creators: name: Bellantuono, Loredana
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The relaxation of a strongly coupled plasma towards the hydrodynamic regime is studied by analyzing the evolution of local and nonlocal observables in the holographic approach. The system is driven in an initial anisotropic and far-from equilibrium state through an impulsive time-dependent deformation (quench) of the boundary spacetime geometry. Effective temperature and entropy density are related to the position and area of a black hole horizon, which has formed as a consequence of the distortion. The behavior of stress-energy tensor, equal-time correlation functions and Wilson loops of different shapes is examined, and a hierarchy among their thermalization times emerges: probes involving shorter length scales thermalize faster.
description: 6 pages, 3 figures. Talk presented at "QCD@Work 2016", International Workshop on QCD, Theory and Experiment, Martina Franca (Taranto), Italy, June 27-30, 2016
Resonance contributions from $χ_{c0}$ in the charmless three-body hadronic $B$ meson decays
Creators: name: Zhang, Ya-Lan
name: Wang, Chao
name: Lin, Yi
name: Xiao, Zhen-Jun
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Within the framework of perturbative QCD factorization, we investigate the nonfactorizable contributions to these factorization-forbidden Quasi-two-body decays $B_{(s)}\rightarrow hχ_{c0}\rightarrow hπ^+π^-(K^+K^-)$ with $ h=π, K$. We compare our predicted branching ratios for the $B_{(s)}\rightarrow Kχ_{c0}\rightarrow Kπ^+π^-(K^+K^-)$ decay with available experiment data as well as predictions by other theoretical studies. The branching ratios of these decays are consistent with data and other theoretical predictions. In the Cabibbo-suppressed decays $B_{(s)}\rightarrow hχ_{c0}\rightarrow hπ^+π^-(K^+K^-)$ with $h=\bar{K}^0,π$, however, the values of the branching ratios are the order of $10^{-7}$ and $10^{-8}$. The ratio $R_{χ_{c0}}$ between the decay $B^+\rightarrow π^+χ_{c0}\rightarrow π^+π^+π^-$ and $B^+\rightarrow K^+χ_{c0}\rightarrow K^+π^+π^-$ and the distribution of branching ratios for different decay modes in invariant mass are considered in this work.
description: 8 pages, 2 figures, accepted for publication in Chin. Phys. C
Local regularity of weak solutions of the hypodissipative Navier-Stokes equations
Creators: name: Kwon, Hyunju
name: Ożański, Wojciech S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We consider the 3D incompressible hypodissipative Navier-Stokes equations, when the dissipation is given as a fractional Laplacian $(-Δ)^s$ for $s\in (\frac34,1)$, and we provide a new bootstrapping scheme that makes it possible to analyse weak solutions locally in space-time. This includes several homogeneous Kato-Ponce type commutator estimates which we localize in space, and which seems applicable to other parabolic systems with fractional dissipation. We also provide a new estimate on the pressure, $\|(-Δ)^s p \|_{\mathcal{H}^1}\lesssim \| (-Δ)^{\frac s2} u \|^2_{L^2}$. We apply our main result to prove that any suitable weak solution $u$ satisfies $\nabla^n u \in L^{p,\infty }_{\mathrm{loc}}(\mathbb{R}^3\times(0,\infty))$ for $p=\frac{2(3s-1)}{n+2s-1}$, $n=1,2$. As a corollary of our local regularity theorem, we improve the partial regularity result of Tang-Yu [Comm. Math. Phys., 334(30), 2015, pp. 1455--1482], and obtain an estimate on the box-counting dimension of the singular set $S$, $d_B(S\cap \{t\geq t_0 \} )\leq \frac13 (15-2s-8s^2) $ for every $t_0>0$.
description: 57 pages, 1 figure
Thickness Engineered Tunnel Field-Effect Transistors based on Phosphorene
Creators: name: Chen, Fan W.
name: Ilatikhameneh, Hesameddin
name: Ameen, Tarek A.
name: Klimeck, Gerhard
name: Rahman, Rajib
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Thickness engineered tunneling field-effect transistors (TE-TFET) as a high performance ultra-scaled steep transistor is proposed. This device exploits a specific property of 2D materials: layer thickness dependent energy bandgap (Eg). Unlike the conventional hetero-junction TFETs, TE-TFET uses spatially varying layer thickness to form a hetero-junction. This offers advantages by avoiding the interface states and lattice mismatch problems. Furthermore, it boosts the ON-current to 1280$μA/μm$ for 15nm channel length. TE-TFET shows a channel length scalability down to 9nm with constant field scaling $E = V_{DD}/L_{ch}= 30V/nm$. Providing a higher ON current, phosphorene TE-TFET outperforms the homojunction phosphorene TFET and the TMD TFET in terms of extrinsic energy-delay product. In this work, the operation principles of TE-TFET and its performance sensitivity to the design parameters are investigated by the means of full-band atomistic quantum transport simulation.
description: 6 figures
The performance of approximate equation of motion coupled cluster for valence and core states of heavy element systems
Creators: name: Halbert, Loïc
name: Gomes, Andre Severo Pereira
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: The equation of motion coupled cluster singles and doubles model (EOM-CCSD) is an accurate, black-box correlated electronic structure approach to investigate electronically excited states and electron attachment or detachment processes. It has also served as a basis for developing less computationally expensive approximate models such as partitioned EOM-CCSD (P-EOM-CCSD), the second-order many-body perturbation theory EOM (EOM-MBPT(2)), and their combination (P-EOM-MBPT(2)) [S. Gwaltney et al., Chem. Phys. Lett. 248, 189-198 (1996)]. In this work we outline an implementation of these approximations for four-component based Hamiltonians and investigate their accuracy relative to EOM-CCSD for valence excitations, valence and core ionizations and electron attachment, and this for a number of systems of atmospheric or astrophysical interest containing elements across the periodic table. We have found that across the different systems and electronic states of different nature considered, partition EOM-CCSD yields results with the largest deviations from the reference, whereas second-order based approaches tend show a generally better agreement with EOM-CCSD. We trace this behavior to the imbalance brought about by the removal of excited state relaxation in the partition approaches, with respect to degree of electron correlation recovered.
description: 5 figures, 4 tables
Non-Hermitian fermions with effective mass
Creators: name: Lima, F. C. E.
name: Monteiro, L. N.
name: Almeida, C. A. S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this work, we readdress the Dirac equation in the position-dependent mass (PDM) scenario. Here, one investigates the quantum dynamics of non-Hermitian fermionic particles with effective mass assuming a $(1+1)$-dimension flat spacetime. In seeking a Schrödinger-like theory with PT symmetry is appropriate to assume a complex potential. This imaginary interaction produces an effective potential purely dependent on mass distribution. Furthermore, we study the non-relativistic limit by adopting the Foldy-Wouthuysen transformation. As a result, that limit leads to an ordering equivalent to the ordering that describes abrupt heterojunctions. Posteriorly, particular cases of mass distribution also were analyzed. Thus, interesting results arise for the case of a linear PDM, which produces an effective harmonic oscillator and induces the emergence of bound states. For a hyperbolic PDM, an effective potential barrier emerges. However, in this case, the fermions behave as free particles with positive-defined energy.
description: 19 pages, 7 captioned figures. To appear in Physica E
Global weak solutions of the Navier-Stokes equations for intermittent initial data in half-space
Creators: name: Bradshaw, Zachary
name: Kukavica, Igor
name: Ożański, Wojciech S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We prove existence of global-in-time weak solutions of the incompressible Navier-Stokes equations in the half-space $\mathbb{R}^3_+$ with initial data in a weighted space that allow non-uniformly locally square integrable functions that grow at spatial infinity in an intermittent sense. The space for initial data is built on cubes whose sides $R$ are proportional to the distance to the origin and the square integral of the data is allowed to grow as a power of $R$. The existence is obtained via a new a priori estimate and stability result in the weighted space, as well as new pressure estimates. Also, we prove eventual regularity of such weak solutions, up to the boundary, for $(x,t)$ satisfying $t>c_1|x|^2 + c_2$, where $c_1,c_2>0$, for a large class of initial data $u_0$, with $c_1$ arbitrarily small. As an application of the existence theorem, we construct global discretely self-similar solutions, thus extending the theory on the half-space to the same generality as the whole space.
description: 32 pages, 1 figure
Airfoil GAN: Encoding and Synthesizing Airfoils for Aerodynamic Shape Optimization
Creators: name: Wang, Yuyang
name: Shimada, Kenji
name: Farimani, Amir Barati
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: The current design of aerodynamic shapes, like airfoils, involves computationally intensive simulations to explore the possible design space. Usually, such design relies on the prior definition of design parameters and places restrictions on synthesizing novel shapes. In this work, we propose a data-driven shape encoding and generating method, which automatically learns representations from existing airfoils and uses the learned representations to generate new airfoils. The representations are then used in the optimization of synthesized airfoil shapes based on their aerodynamic performance. Our model is built upon VAEGAN, a neural network that combines Variational Autoencoder with Generative Adversarial Network and is trained by the gradient-based technique. Our model can (1) encode the existing airfoil into a latent vector and reconstruct the airfoil from that, (2) generate novel airfoils by randomly sampling the latent vectors and mapping the vectors to the airfoil coordinate domain, and (3) synthesize airfoils with desired aerodynamic properties by optimizing learned features via a genetic algorithm. Our experiments show that the learned features encode shape information thoroughly and comprehensively without predefined design parameters. By interpolating/extrapolating feature vectors or sampling from Gaussian noises, the model can automatically synthesize novel airfoil shapes, some of which possess competitive or even better aerodynamic properties comparing to airfoils used for model training purposes. By optimizing shapes on the learned latent domain via a genetic algorithm, synthesized airfoils can evolve to target aerodynamic properties. This demonstrates an efficient learning-based airfoil design framework, which encodes and optimizes the airfoil on the latent domain and synthesizes promising airfoil candidates for required aerodynamic performance.
description: Published in Journal of Computational Design and Engineering. 13 pages, 13 figures, 1 table
Snapshot: introductions to key themes and topics in relation to the UK Armed Forces community, including veterans and their families
Creators: name: Forces In Mind Trust Research Centre FiMT RC
Publisher: name: Anglia Ruskin University
Year: 2020
Subjects: subject: Sociology
subject: FOS: Sociology

description: Snapshots are plain language summaries of research and evidence relating to the UK Armed Forces and veteran community.
Snapshots are designed to aid understanding of the complex issues at play in relation to the Armed Forces, and to support decision-making processes by bridging the gaps between academic research, government and charitable policy, Service provision and public opinion. Snapshots are aimed primarily at those working in policy-making and Service provision roles for the Armed Forces, and are also useful to those seeking facts, figures and informed comment to empower a more objective discussion among the wider population, including the Armed Forces community and the media. The purpose of Snapshots is to review and interpret research and policy and to set out concise, plain language summaries to facilitate understanding and perception.

Snapshots available at present: 1) education and training 2) employment 3) housing 4) physical health 5) mental health 6) criminal justice system 7) military families 8) research
Further Snapshots will be made available in due course and Snapshots are updated on a rolling basis.
An anisotropic regularity condition for the 3D incompressible Navier-Stokes equations for the entire exponent range
Creators: name: Kukavica, Igor
name: Ożański, Wojciech S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We show that a suitable weak solution to the incompressible Navier-Stokes equations on ${\mathbb{R}^3\times(-1,1)}$ is regular on $\mathbb{R}^3\times(0,1]$ if $\partial_3 u $ belongs to $M^{2p/(2p-3),α} ((-1,0);L^p (\mathbb{R}^3 ))$ for any $α>1$ and $p\in (3/2,\infty)$, which is a logarithmic-type variation of a Morrey space in time. For each $α>1$ this space is, up to a logarithm, critical with respect to the scaling of the equations, and contains all spaces $L^q ((-1,0);L^p (\mathbb{R}^3 ))$ that are subcritical, that is for which $2/q+3/p<2$.
description: 10 pages