cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Phase diagram of one-dimensional driven-dissipative exciton-polariton condensates
Creators: name: Vercesi, Francesco
name: Fontaine, Quentin
name: Ravets, Sylvain
name: Bloch, Jacqueline
name: Richard, Maxime
name: Canet, Léonie
name: Minguzzi, Anna
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We consider a one-dimensional driven-dissipative exciton-polariton condensate under incoherent pump, described by the stochastic generalized Gross-Pitaevskii equation. It was shown that the condensate phase dynamics maps under some assumptions to the Kardar-Parisi-Zhang (KPZ) equation, and the temporal coherence of the condensate follows a stretched exponential decay characterized by KPZ universal exponents. In this work, we determine the main mechanisms which lead to the departure from the KPZ phase, and identify three possible other regimes: (i) a soliton-patterned regime at large interactions and weak noise, populated by localized structures analogue to dark solitons; (ii) a vortex-disordered regime at high noise and weak interactions, dominated by point-like phase defects in space-time; (iii) a defect-free reservoir-textured regime where the adiabatic approximation breaks down. We characterize each regime by the space-time maps, the first-order correlations, the momentum distribution and the density of topological defects. We thus obtain the phase diagram at varying noise, pump intensity and interaction strength. Our predictions are amenable to observation in state-of-art experiments with exciton-polaritons.
[Carta Aberta à Humanidade] A Dinâmica da Água (2022)
Creators: name: Teia, Luis
Publisher: name: figshare
Year: 2022
Subjects: classificationCode: 519999
subject: Other physical sciences not elsewhere classified

description: Esta carta partilha nova informação sobre a dinâmica da água, numa perspectiva geométrica em que o que aparenta ser o caos no fundo é um sistema complexo de arranjo molecular, governado por um modelo geométrico recentemente definido (e publicado em journais matemáticos no Canada e Australia).-------------------------------------------------------------------------For more public data, please visit my Figshare profile: https://figshare.com/authors/Luis_Teia/10811244
A Simple Bootstrap for Chatterjee's Rank Correlation
Creators: name: Dette, Holger
name: Kroll, Marius
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62F40, 62G05, 62H20

description: We prove that an $m$ out of $n$ bootstrap procedure for Chatterjee's rank correlation is consistent whenever asymptotic normality of Chatterjee's rank correlation can be established. In particular, we prove that $m$ out of $n$ bootstrap works for continuous as well as for discrete data with independent coordinates; furthermore, simulations indicate that it also performs well for discrete data with dependent coordinates, and that it outperforms alternative estimation methods. Consistency of the bootstrap is proved in the Kolmogorov as well as in the Wasserstein distance.
Anomalous $h/2e$ periodicity and Majorana zero modes in chiral Josephson junctions
Creators: name: Sun, Zi-Ting
name: Hu, Jin-Xin
name: Xie, Ying-Ming
name: Law, K. T.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Recent experiments reported that quantum Hall chiral edge state-mediated Josephson junctions (chiral Josephson junctions) could exhibit Fraunhofer oscillations with a periodicity of either $h/e$ [Vignaud \textit{et al}.,~Nature~(2023)] or $h/2e$ [Amet \textit{et al}.,~Science~\textbf{352}~966~(2016)]. While the $h/e$-periodic component of the supercurrent had been anticipated theoretically before, the emergence of the $h/2e$-periodicity is still not fully understood. In this work, we show that the chiral edge states coupled to the superconductors become chiral Andreev edge states. In short junctions, the coupling of the chiral Andreev edge states can cause the $h/2e$-magnetic flux periodicity. Our theory resolves the long-standing puzzle concerning the appearance of the $h/2e$-periodicity in chiral Josephson junctions. Furthermore, we explain that when the chiral Andreev edge state couple, a pair of localized Majorana modes appear at the ends of the Josephson junction, which are robust and independent of the phase difference between the two superconductors. As the $h/2e$-periodicity and the Majorana zero modes have the same physical origin, the Fraunhofer oscillation period can be used to identify the regime with Majorana zero modes.
description: 6 pages, 3 figures, plus Supplemental Material
Inflation and Bounce from Classical and Loop Quantum Cosmology Imperfect Fluids
Creators: name: Oikonomou, V. K.
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We investigate how various inflationary and bouncing cosmologies can be realized by imperfect fluids with a generalized equation of state, in the context of both classical and loop quantum cosmology. With regards to the inflationary cosmologies, we study the intermediate inflation scenario, the $R^2$ inflation scenario and two constant-roll inflation scenarios and with regards to the bouncing cosmologies we study the matter bounce scenario, the singular bounce and the super bounce scenario. Within the context of the classical cosmology, we calculate the spectral index of the power spectrum of primordial curvature perturbations, the scalar-to-tensor ratio and the running of the spectral index and we compare the resulting picture with the Planck data. As we demonstrate, partial compatibility with the observational data is achieved in the imperfect fluid description, however none of the above scenarios is in full agreement with data. This result shows that although it is possible to realize various cosmological scenarios using different theoretical frameworks, it is not guaranteed that all the theoretical descriptions are viable.
description: IJMPD Accepted
[Carta Aberta à Humanidade] A Origem da Vida (2022)
Creators: name: Teia, Luis
Publisher: name: figshare
Year: 2022
Subjects: classificationCode: 379999
subject: Other earth sciences not elsewhere classified

description: Esta carta partilha alguma informação sobre a origem da vida, não só como as entidades biologicas que vemos na Terra, mas também (e mais importante) a migração de informação em padrões coerentes no Cosmos.-------------------------------------------------------------------------For more public data, please visit my Figshare profile: https://figshare.com/authors/Luis_Teia/10811244
GaborPINN: Efficient physics informed neural networks using multiplicative filtered networks
Creators: name: Huang, Xinquan
name: Alkhalifah, Tariq
Publisher: name: arXiv
Year: 2023
Subjects: subject: Geophysics (physics.geo-ph)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: The computation of the seismic wavefield by solving the Helmholtz equation is crucial to many practical applications, e.g., full waveform inversion. Physics-informed neural networks (PINNs) provide functional wavefield solutions represented by neural networks (NNs), but their convergence is slow. To address this problem, we propose a modified PINN using multiplicative filtered networks, which embeds some of the known characteristics of the wavefield in training, e.g., frequency, to achieve much faster convergence. Specifically, we use the Gabor basis function due to its proven ability to represent wavefields accurately and refer to the implementation as GaborPINN. Meanwhile, we incorporate prior information on the frequency of the wavefield into the design of the method to mitigate the influence of the discontinuity of the represented wavefield by GaborPINN. The proposed method achieves up to a two-magnitude increase in the speed of convergence as compared with conventional PINNs.
[ARTICLE] An Exact Connection between π and the Golden Ratio φ (Canadian Journal of Mathematics Research / 2022)
Creators: name: Teia, Luis
Publisher: name: figshare
Year: 2022
Subjects: classificationCode: 490499
subject: Pure mathematics not elsewhere classified
classificationCode: 499999
subject: Other mathematical sciences not elsewhere classified
classificationCode: 490107
subject: Mathematical methods and special functions
classificationCode: 490199
subject: Applied mathematics not elsewhere classified
classificationCode: 490401
subject: Algebra and number theory

description: This article establishes a geometrical and mathematical bridge between the universal constant π and the golden ratio φ by interrelating the construction of the area of a circle using two approaches: one formed using the rotation of a regular unit pentagon and the other one from the rotation of its inverse ― the pentagram of side reference φ. The mathematical end result is a linear expression of π as a function of φ. As an interesting side result, an expression for the area of a circle is derived based on the golden ratio φ and a geometrically motivated coefficient. A scripted program for the verification of the derived expressions is provided.
CopyrightsCopyright for this article is retained by the author(s), with first publication rights granted to the journal. This is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/).-------------------------------------------------------------------------For more public data, please visit my Figshare profile: https://figshare.com/authors/Luis_Teia/10811244
Low mass variable stars in the globular cluster NGC 6397
Creators: name: Martinazzi, E.
name: Kepler, S. O.
name: Costa, J. E. S.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We have conducted a photometric survey of the globular cluster NGC 6397 in a search for variable stars. We obtained ~11h of time-resolved photometric images with one ne European Southern Observatory-Very Large Telescope using the FOcal Reducer and low dispersion Spectrograph imager distributed over two consecutive nights. We analyzed 8391 light curves of stars brighter than magnitude 23 with the 465 nm-filter, and we identified 412 variable stars, reaching ~ 4.8 +- 0.2 per cent of variability with timescales between 0.004 and 2d, with amplitudes variation greater than +- 0.2 mag.
description: 9 figures, complementary data
[ARTICLE] An Exact Connection between π and the Golden Ratio φ (Canadian Journal of Mathematics Research / 2022)
Creators: name: Teia, Luis
Publisher: name: figshare
Year: 2022
Subjects: classificationCode: 490401
subject: Algebra and number theory
classificationCode: 490402
subject: Algebraic and differential geometry
classificationCode: 490499
subject: Pure mathematics not elsewhere classified

description: ABSTRACT This article establishes a geometrical and mathematical bridge between the universal constant π and the golden ratio φ by interrelating the construction of the area of a circle using two approaches: one formed using the rotation of a regular unit pentagon and the other one from the rotation of its inverse ― the pentagram of side reference φ. The mathematical end result is a linear expression of π as a function of φ. As an interesting side result, an expression for the area of a circle is derived based on the golden ratio φ and a geometrically motivated coefficient. A scripted program for the verification of the derived expressions is provided. Copyrights Copyright for this article is retained by the author(s), with first publication rights granted to the journal. This is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/).
On Quasiconvexity of Precompact-Subset Spaces
Creators: name: Akofor, Earnest
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Topology (math.GN)
subject: FOS: Mathematics
subject: Primary 52A01, Secondary 54B20 54E05 40A30 03E75

description: Let $X$ be a metric space and $BCl(X)$ the collection of nonempty bounded closed subsets of $X$ as a metric space with respect to Hausdorff distance. We study both characterization and representation of Lipschitz paths in $BCl(X)$ in terms of Lipschitz paths in $X$ and in the completion of $X$. We show that a full characterization and representation is possible in any subspace $\mathcal{J}\subset BCl(X)$ that (i) consists of precompact subsets of $X$, (ii) contains the singletons $\{x\}$ for every $x\in X$, and (iii) satisfies $BCl(C)\subset\mathcal{J}$ for every $C\in\mathcal{J}$. When $X$ is geodesic, we investigate quasiconvexity of $\mathcal{J}$ for some instances of $\mathcal{J}$, especially when $\mathcal{J}$ consists of finite subsets of $X$.
description: J Anal (2024)
Edit Temporal-Consistent Videos with Image Diffusion Model
Creators: name: Wang, Yuanzhi
name: Li, Yong
name: Zhang, Xiaoya
name: Liu, Xin
name: Dai, Anbo
name: Chan, Antoni B.
name: Cui, Zhen
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Large-scale text-to-image (T2I) diffusion models have been extended for text-guided video editing, yielding impressive zero-shot video editing performance. Nonetheless, the generated videos usually show spatial irregularities and temporal inconsistencies as the temporal characteristics of videos have not been faithfully modeled. In this paper, we propose an elegant yet effective Temporal-Consistent Video Editing (TCVE) method to mitigate the temporal inconsistency challenge for robust text-guided video editing. In addition to the utilization of a pretrained T2I 2D Unet for spatial content manipulation, we establish a dedicated temporal Unet architecture to faithfully capture the temporal coherence of the input video sequences. Furthermore, to establish coherence and interrelation between the spatial-focused and temporal-focused components, a cohesive spatial-temporal modeling unit is formulated. This unit effectively interconnects the temporal Unet with the pretrained 2D Unet, thereby enhancing the temporal consistency of the generated videos while preserving the capacity for video content manipulation. Quantitative experimental results and visualization results demonstrate that TCVE achieves state-of-the-art performance in both video temporal consistency and video editing capability, surpassing existing benchmarks in the field.
description: 10 pages, 7 figures
Decision-Making for Land Conservation: A Derivative-Free Optimization Framework with Nonlinear Inputs
Creators: name: Buhler, Cassidy K.
name: Benson, Hande Y.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: K.4.0
subject: 92-10 (Primary) 90C90 (Secondary)

description: Protected areas (PAs) are designated spaces where human activities are restricted to preserve critical habitats. Decision-makers are challenged with balancing a trade-off of financial feasibility with ecological benefit when establishing PAs. Given the long-term ramifications of these decisions and the constantly shifting environment, it is crucial that PAs are carefully selected with long-term viability in mind.
 Using AI tools like simulation and optimization is common for designating PAs, but current decision models are primarily linear. In this paper, we propose a derivative-free optimization framework paired with a nonlinear component, population viability analysis (PVA). Formulated as a mixed integer nonlinear programming (MINLP) problem, our model allows for linear and nonlinear inputs. Connectivity, competition, crowding, and other similar concerns are handled by the PVA software, rather than expressed as constraints of the optimization model. In addition, we present numerical results that serve as a proof of concept, showing our models yield PAs with similar expected risk to that of preserving every parcel in a habitat, but at a significantly lower cost.
 The overall goal is to promote interdisciplinary work by providing a new mathematical programming tool for conservationists that allows for nonlinear inputs and can be paired with existing ecological software. Our code and data are available at https://github.com/cassiebuhler/conservation-dfo.
description: 11 pages, 6 figures. This is the extended version of our paper accepted to the Proceedings of the 38th AAAI Conference on Artificial Intelligence (AAAI-24). This version includes the technical appendix
Topological phase transition from trigonal warping in van der Waals multilayers
Creators: name: Zeng, Junjie
name: Ren, Yafei
name: Zhang, Kunhua
name: Qiao, Zhenhua
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In van der Waals multilayers of triangular lattice, trigonal warping occurs universally due to the interlayer hopping. We theoretically investigate the effect of trigonal warping upon distinctive topological phases, like the quantum anomalous Hall effect (QAHE) and the quantum valley Hall effect (QVHE). Taking Bernal-stacked bilayer graphene as an example, we find that the trigonal warping plays a crucial role in the formation of QAHE in large exchange field and/or interlayer potential difference by inducing extra band inversion points at momentum further away from high symmetric point. The presence of trigonal warping shrinks the phase space of QAHE and QVHE, leading to the emergence of valley-polarized QAHE with high Chern numbers ranging from $ \mathcal{C}=-7 $ to $ 7 $. These results suggest that the universal trigonal warping may play important role when the Bloch states at momentum away from high-symmetric points are involved.
description: 4+1 pages, 3 figures
MolGrapher: Graph-based Visual Recognition of Chemical Structures
Creators: name: Morin, Lucas
name: Danelljan, Martin
name: Agea, Maria Isabel
name: Nassar, Ahmed
name: Weber, Valery
name: Meijer, Ingmar
name: Staar, Peter
name: Yu, Fisher
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: The automatic analysis of chemical literature has immense potential to accelerate the discovery of new materials and drugs. Much of the critical information in patent documents and scientific articles is contained in figures, depicting the molecule structures. However, automatically parsing the exact chemical structure is a formidable challenge, due to the amount of detailed information, the diversity of drawing styles, and the need for training data. In this work, we introduce MolGrapher to recognize chemical structures visually. First, a deep keypoint detector detects the atoms. Second, we treat all candidate atoms and bonds as nodes and put them in a graph. This construct allows a natural graph representation of the molecule. Last, we classify atom and bond nodes in the graph with a Graph Neural Network. To address the lack of real training data, we propose a synthetic data generation pipeline producing diverse and realistic results. In addition, we introduce a large-scale benchmark of annotated real molecule images, USPTO-30K, to spur research on this critical topic. Extensive experiments on five datasets show that our approach significantly outperforms classical and learning-based methods in most settings. Code, models, and datasets are available.
Fast near-infrared photodetectors based on nontoxic and solution-processable AgBiS2
Creators: name: Huang, Yi-Teng
name: Nodari, Davide
name: Furlan, Francesco
name: Zhang, Youcheng
name: Rusu, Marin
name: Dai, Linjie
name: Andaji-Garmaroudi, Zahra
name: Stranks, Samuel D.
name: Sirringhaus, Henning
name: Rao, Akshay
name: Gasparini, Nicola
name: Hoye, Robert L. Z.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Solution-processable near-infrared (NIR) photodetectors are urgently needed for a wide range of next-generation electronics, including sensors, optical communications and bioimaging. However, there is currently a compromise between low toxicity and slow (<300 kHz cut-off frequency) organic materials versus faster detectors (>300 kHz cut-off frequency) based on compounds containing toxic lead or cadmium. Herein, we circumvent this trade-off by developing solution-processed AgBiS2 photodetectors with high cut-off frequencies under both white light (>1 MHz) and NIR (approaching 500 kHz) illumination. These high cut-off frequencies are due to the short transit distances of charge-carriers in the AgBiS2 photodetectors, which arise from the strong light absorption of these materials, such that film thicknesses well below 120 nm are adequate to absorb >65% of near-infrared to visible light. By finely controlling the thickness of the photoactive layer, we can modulate the charge-collection efficiency, achieve low dark current densities, and minimize the effects of ion migration to realize fast photodetectors that are stable in air. These outstanding characteristics enable real-time heartbeat sensors based on NIR AgBiS2 photodetectors.
 # equal contribution, * corresponding authors
description: 29 pages, 4 figures, 1 table
AGN luminosity and stellar age -- two missing ingredients for AGN unification as seen with iPTF supernovae
Creators: name: Villarroel, Beatriz
name: Nyholm, Anders
name: Karlsson, Torgny
name: Comerón, Sébastien
name: Korn, Andreas
name: Sollerman, Jesper
name: Zackrisson, Erik
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Active Galactic Nuclei (AGN) are extremely powerful cosmic objects, driven by accretion of hot gas upon super-massive black holes. The zoo of AGN classes are divided into two major groups, with Type-1 AGN displaying broad Balmer emission lines and Type-2 narrow ones. For a long time it was believed that a Type-2 AGN is a Type-1 AGN viewed through a dusty kiloparsec-size torus, but an emerging body of observations suggests more than just the viewing angle matters. Here we report significant differences in supernova counts and classes in the first study to date of supernovae near Type-1 and Type-2 AGN host galaxies, using data from the intermediate Palomar Transient Factory, the Sloan Digital Sky Survey Data Release 7 and Galaxy Zoo. We detect many more supernovae in Type-2 AGN hosts (size of effect $\sim$ 5.1$σ$) compared to Type-1 hosts, which shows that the two classes of AGN are located inside host galaxies with different properties. In addition, Type-1 and Type-2 AGN that are dominated by star formation according to WISE colours $m_{W1} - m_{W2} < 0.5$ and are matched in 22 $μ$m absolute magnitude differ by a factor of ten in $L$[OIII]$λ$5007 luminosity, suggesting that when residing in similar type of host galaxies Type-1 AGN are much more luminous. Our results demonstrate two more factors that play an important role in completing the current picture: the age of stellar populations and the AGN luminosity. This has immediate consequences for understanding the many AGN classes and galaxy evolution.
description: Accepted to the Astrophysical Journal (ApJ)
Differential cross-section measurements of the production of four charged leptons in association with two jets using the ATLAS detector
Creators: name: ATLAS Collaboration
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Differential cross-sections are measured for the production of four charged leptons in association with two jets. These measurements are sensitive to final states in which the jets are produced via the strong interaction as well as to the purely-electroweak vector boson scattering process. The analysis is performed using proton-proton collision data collected by ATLAS at $\sqrt{s}=13$ TeV and with an integrated luminosity of 140 fb$^{-1}$. The data are corrected for the effects of detector inefficiency and resolution and are compared to state-of-the-art Monte Carlo event generator predictions. The differential cross-sections are used to search for anomalous weak-boson self-interactions that are induced by dimension-six and dimension-eight operators in Standard Model effective field theory.
description: 49 pages in total, author list starting page 32, 12 figures, 4 tables, published in JHEP. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2020-02
[WHITE PAPER] Geometry of the Electron Cloud based on the Triangular Spin Model, and its Modes of Vibration (2022)
Creators: name: Teia, Luis
Publisher: name: figshare
Year: 2022
Subjects: classificationCode: 519999
subject: Other physical sciences not elsewhere classified

description: This article aims to provide a prediction of the progressive geometrical spatial arrangement for electrons ― based on the triangular spin model (presented in the article at the link below) ― stacking on top of each other to form an sub-orbit/orbit. The locations are not actual but highlight the probabilistic most likely relative position in space for each electron, following the spin stacking guidelines of the aforementioned model. It is the assumption that the electrons are geometrically locked into certain regions of space on the electron cloud. From this geometry, the various identified modes of vibration are explained as particular cyclic motions of groups of electrons, resulting in an alternative explanation parallel to the classical theory. The article is not intended to provide all the answers, but it hopes to provide the foundation for a new way to look ― using geomtry as a tool ― at the electron cloud.-------------------------------------------------------------------------For more public data, please visit my Figshare profile: https://figshare.com/authors/Luis_Teia/10811244
Urns with Multiple Drawings and Graph-Based Interaction
Creators: name: Dahiya, Yogesh
name: Sahasrabudhe, Neeraja
Publisher: name: arXiv
Year: 2023
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60K35, 60F15, 60F05

description: Consider a finite undirected graph and place an urn with balls of two colours at each vertex. At every discrete time step, for each urn, a fixed number of balls are drawn from that same urn with probability $p$, and from a randomly chosen neighbour of that urn with probability $1-p$. Based on what is drawn, the urns then reinforce themselves or their neighbours. For every ball of a given colour in the sample, in case of Pólya-type reinforcement, a constant multiple of balls of that colour is added while in case of Friedman-type reinforcement, balls of the other colour are reinforced. These different choices for reinforcement give rise to multiple models. In this paper, we study the convergence of the fraction of balls of either colour across urns for all of these models. We show that in most cases the urns synchronize, that is, the fraction of balls of either colour in each urn converges to the same limit almost surely. A different kind of asymptotic behaviour is observed on bipartite graphs. We also prove similar results for the case of finite directed graphs.
description: 32 pages, 2 figures
Eigenstate Thermalization in 2+1 dimensional SU(2) Lattice Gauge Theory
Creators: name: Ebner, Lukas
name: Müller, Berndt
name: Schäfer, Andreas
name: Seidl, Clemens
name: Yao, Xiaojun
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present preliminary numerical evidence for the hypothesis that the Hamiltonian SU(2) gauge theory discretized on a lattice obeys the Eigenstate Thermalization Hypothesis (ETH). To do so we study three approximations: (a) a linear plaquette chain in a reduced Hilbert space limiting the electric field basis to $j=0,\frac{1}{2}$ , (b) a two-dimensional honeycomb lattice with periodic or closed boundary condition and the same Hilbert space constraint, and (c) a chain of only three plaquettes but such a sufficiently large electric field Hilbert space ($j \leq \frac{7}{2})$ that convergence of all energy eigenvalues in the analyzed energy window is observed. While an unconstrained Hilbert space is required to reach the continuum limit of SU(2) gauge theory, numerical resource constraints do not permit us to realize this requirement for all values of the coupling constant and large lattices. In each of the three studied cases we check first for random matrix theory (RMT) behavior in the eigenenergy spectrum and then analyze the diagonal as well as the off-diagonal matrix elements between energy eigenstates for a few operators. Within current uncertainties all results for (a), (b) and (c) agree with ETH predictions. Furthermore, we find the off-diagonal matrix elements of the electric energy operator exhibit RMT behavior in frequency windows that are small enough in (b) and (c). To unambiguously establish ETH behavior and determine for which class of operators it applies, an extension of our investigations is necessary.
description: 18 pages, 27 figures, v2: minor changes, published version; v3: corrected a typo in the caption of Fig.8
Experimental realization of supergrowing fields
Creators: name: R., Sethuraj K.
name: Karmakar, Tathagata
name: Wadood, S. A.
name: Jordan, Andrew N.
name: Vamivakas, A. Nick
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Supergrowth refers to the local amplitude growth rate of a signal being faster than its fastest Fourier mode. In contrast, superoscillation pertains to the variation of the phase. Compared to the latter, supergrowth can have exponentially higher intensities and promises improvement over superoscillation-based superresolution imaging. Here, we demonstrate the experimental synthesis of controlled supergrowing fields with a maximum growth rate of ~19.1 times the system-bandlimit. Our work is an essential step toward realizing supergrowth-based far-field superresolution imaging.
Robust Dynamic Transmission and Renewable Generation Expansion Planning: Walking Towards Sustainable Systems
Creators: name: Roldán, Cristina
name: de la Nieta, Agustín A. Sánchez
name: Mínguez, Roberto
name: García-Bertrand, Raquel
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: Nowadays, the transition from a conventional generation system to a renewable generation system is one of the most difficult challenges for system operators and companies. There are several reasons: the long-standing impact of investment decisions, the proper integration of renewable sources into the system, the present and future uncertainties, and the convenience to consider an integrated year-by-year representation of both uncertainties and investment decisions. However, recent breakthroughs in Dynamic Transmission Network Expansion Planning (DTNEP) have demonstrated that the use of robust optimization might render this problem computationally tractable for real systems. This paper intends to consider not only the capacity expansion of lines, but the construction and/or dismantling of renewable and conventional generation facilities as well. The Dynamic Transmission Network and Renewable Generation Expansion Planning (DTNRGEP) problem is formulated as an adaptive robust optimization problem with three levels. First level minimizes the investment costs of transmission network and generation expansion planning, the second level maximizes system operational costs with respect to uncertain parameters, while the third level minimizes those operational costs with respect to operational decisions. The method is tested for two cases: i) an illustrative example based on Garver IEEE system and ii) a case study using the IEEE 118-bus system. Numerical results from these examples demonstrate that the proposed model allows making optimal decisions towards reaching a sustainable power system, while overcoming problem size limitations and computational intractability for realistic cases.
description: 8 pages, 1 figure
[WHITE PAPER] Fundamentals of Gravity and its Disruption
Creators: name: Teia, Luis
Publisher: name: figshare
Year: 2022
Subjects: classificationCode: 519999
subject: Other physical sciences not elsewhere classified

description: The following article introduces some disruptive ideas about gravity, and how this understanding can provide control over the physics of weightlessness, by firstly making the innovative assumption that space is a fluid. The article is written to those who are open-minded, and seek to explore explanations of reality outside-the-box of traditional concepts institutionalized by society.-------------------------------------------------------------------------For more public data, please visit my Figshare profile: https://figshare.com/authors/Luis_Teia/10811244
Photometric evolution of seven recent novae and the double component characterizing the lightcurve of those emitting in gamma rays
Creators: name: Munari, U.
name: Hambsch, F. -J.
name: Frigo, A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The BVI lightcurves of seven recent novae have been extensively mapped with daily robotic observations from Atacama (Chile). They are V1534 Sco, V1535 Sco, V2949 Oph, V3661 Oph, MASTER OT J010603.18-744715.8, TCP J1734475-240942 and ASASSN-16ma. Five belong to the Bulge, one to SMC and another is a Galactic disk object. The two program novae detected in gamma-rays by Fermi-LAT (TCP J1734475-240942 and ASASSN-16ma) are Bulge objects with unevolved companions. They distinguish themselves in showing a double-component optical lightcurve. The first component to develop is the fireball from freely-expanding, ballistic-launched ejecta with the time of passage through maximum which is strongly dependent on wavelength (~1 day delay between B and I bands). The second component, emerging simultaneously with the nova detection in gamma-rays, evolves at a slower pace, its optical brightness being proportional to the gamma-ray flux, and its passage through maximum not dependent on wavelength. The fact that gamma-rays are detected at peak flux level differing by 4x from novae at the distance of the Bulge seems to suggest that gamma-ray emission is not a widespread property of normal novae. We discuss the advantages offered by high-quality photometric observations collected with only one telescope (as opposed to data provided by a number of different instruments), and observe the effects of: wavelength dependence of a fireball expansion, recombination in the flashed wind of a giant companion, subtle presence of hiccups, super-soft X-ray emission on and off. Four program novae (V2949 Oph, V3661 Oph, TCP J18102829-2729590, and ASASSN-16ma) are found to have normal dwarf companions, while V1534 Sco contains an M3III giant, V1535 Sco a K-type giant, and MASTER OT J010603.18-744715.8 a sub-giant.
description: MNRAS, 18 pages, 17 figures, 3 tables (1 electronic)
[WHITE PAPER] Fundamentals of Gravity and its Disruption
Creators: name: Teia, Luis
Publisher: name: figshare
Year: 2022
Subjects: classificationCode: 519999
subject: Other physical sciences not elsewhere classified

description: The following article introduces some disruptive ideas about gravity, and how this understanding can provide control over this physics of weightlessness, by firstly making the innovative assumption that space is a fluid. The article is written to those who are open-minded, and seek to explore explanations of reality outside-the-box of traditional concepts institutionalized by society.
Operator representations of frames: boundedness, duality, and stability
Creators: name: Christensen, Ole
name: Hasannasab, Marzieh
Publisher: name: arXiv
Year: 2017
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 42C15

description: The purpose of the paper is to analyze frames $\{f_k\}_{k\in \mathbf Z}$ having the form $\{T^kf_0\}_{k\in\mathbf Z}$ for some linear operator $T: \mbox{span} \{f_k\}_{k\in \mathbf Z} \to \mbox{span}\{f_k\}_{k\in \mathbf Z}$. A key result characterizes boundedness of the operator $T$ in terms of shift-invariance of a certain sequence space. One of the consequences is a characterization of the case where the representation $\{f_k\}_{k\in \mathbf Z}=\{T^kf_0\}_{k\in\mathbf Z}$ can be achieved for an operator $T$ that has an extension to a bounded bijective operator $\widetilde{T}: \cal H \to \cal H.$ In this case we also characterize all the dual frames that are representable in terms of iterations of an operator $V;$ in particular we prove that the only possible operator is $V=(\widetilde{T}^*)^{-1}.$ Finally, we consider stability of the representation $\{T^kf_0\}_{k\in\mathbf Z};$ rather surprisingly, it turns out that the possibility to represent a frame on this form is sensitive towards some of the classical perturbation conditions in frame theory. Various ways of avoiding this problem will be discussed. Throughout the paper the results will be connected with the operators and function systems appearing in applied harmonic analysis, as well as with general group representations.
Overlap junctions for high coherence superconducting qubits
Creators: name: Wu, X.
name: Long, J. L.
name: Ku, H. S.
name: Lake, R. E.
name: Bal, M.
name: Pappas, D. P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Fabrication of sub-micron Josephson junctions is demonstrated using standard processing techniques for high-coherence, superconducting qubits. These junctions are made in two separate lithography steps with normal-angle evaporation. Most significantly, this work demonstrates that it is possible to achieve high coherence with junctions formed on aluminum surfaces cleaned in situ with Ar milling before the junction oxidation. This method eliminates the angle-dependent shadow masks typically used for small junctions. Therefore, this is conducive to the implementation of typical methods for improving margins and yield using conventional CMOS processing. The current method uses electron-beam lithography and an additive process to define the top and bottom electrodes. Extension of this work to optical lithography and subtractive processes is discussed.
description: 4 pages, 3 figures
C$_{60}^+$ - looking for the bucky-ball in interstellar space
Creators: name: Galazutdinov, G. A.
name: Shimansky, V. V.
name: Bondar, A.
name: Valyavin, G.
name: Krelowski, J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The laboratory gas phase spectrum recently published by Campbell et al. has reinvigorated attempts to confirm the presence of the C$_{60}^+$ cation in the interstellar medium, thorough an analysis of the spectra of hot, reddened stars. This search is hindered by at least two issues that need to be addressed: (i) the wavelength range of interest is severely polluted by strong water- vapour lines coming from the Earth's atmosphere; (ii) one of the major bands attributed to C$_{60}^+$, at 9633 Å, is blended with the stellar Mg{\sc ii} line, which is susceptible to non-local-thermodynamic equilibrium effects in hot stellar atmospheres. Both these issues are here carefully considered here for the first time, based on high-resolution and high signal-to-noise ratio echellé spectra for 19 lines of sight. The result is that the presence of C$_{60}^+$ in interstellar clouds is brought into question.
description: 10 pages, 11 figures
Receding-Constraint Model Predictive Control using a Learned Approximate Control-Invariant Set
Creators: name: Lunardi, Gianni
name: La Rocca, Asia
name: Saveriano, Matteo
name: Del Prete, Andrea
Publisher: name: arXiv
Year: 2023
Subjects: subject: Robotics (cs.RO)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In recent years, advanced model-based and data-driven control methods are unlocking the potential of complex robotics systems, and we can expect this trend to continue at an exponential rate in the near future. However, ensuring safety with these advanced control methods remains a challenge. A well-known tool to make controllers (either Model Predictive Controllers or Reinforcement Learning policies) safe, is the so-called control-invariant set (a.k.a. safe set). Unfortunately, for nonlinear systems, such a set cannot be exactly computed in general. Numerical algorithms exist for computing approximate control-invariant sets, but classic theoretic control methods break down if the set is not exact. This paper presents our recent efforts to address this issue. We present a novel Model Predictive Control scheme that can guarantee recursive feasibility and/or safety under weaker assumptions than classic methods. In particular, recursive feasibility is guaranteed by making the safe-set constraint move backward over the horizon, and assuming that such set satisfies a condition that is weaker than control invariance. Safety is instead guaranteed under an even weaker assumption on the safe set, triggering a safe task-abortion strategy whenever a risk of constraint violation is detected. We evaluated our approach on a simulated robot manipulator, empirically demonstrating that it leads to less constraint violations than state-of-the-art approaches, while retaining reasonable performance in terms of tracking cost, number of completed tasks, and computation time.
description: 7 pages, 3 figures, 3 tables, 2 pseudo-algo, conference
Pulse shape optimization for electron-positron production in rotating fields
Creators: name: Fillion-Gourdeau, François
name: Hebenstreit, Florian
name: Gagnon, Denis
name: MacLean, Steve
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We optimize the pulse shape and polarization of time-dependent electric fields to maximize the production of electron-positron pairs via strong field quantum electrodynamics processes. The pulse is parametrized in Fourier space by a B-spline polynomial basis, which results in a relatively low-dimensional parameter space while still allowing for a large number of electric field modes. The optimization is performed by using a parallel implementation of the differential evolution, one of the most efficient metaheuristic algorithms. The computational performance of the numerical method and the results on pair production are compared with a local multistart optimization algorithm. These techniques allow us to determine the pulse shape and field polarization that maximize the number of produced pairs in computationally accessible regimes.
description: 16 pages, 10 figures
Standard siren cosmology in the era of the 2.5-generation ground-based gravitational wave detectors: bright and dark sirens of LIGO Voyager and NEMO
Creators: name: Jin, Shang-Jie
name: Zhu, Rui-Qi
name: Song, Ji-Yu
name: Han, Tao
name: Zhang, Jing-Fei
name: Zhang, Xin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The 2.5-generation (2.5G) ground-based gravitational wave (GW) detectors LIGO Voyager and NEMO are expected to be operational in the late 2020s and early 2030s. In this work, we explore the potential of GW standard sirens observed by the 2.5G GW detectors in measuring cosmological parameters, especially for the Hubble constant. Using GWs to measure cosmological parameters is inherently challenging, especially for 2.5G detectors, given their limited capability, which results in weaker constraints on cosmological parameters from the detected standard sirens. However, the measurement of the Hubble constant using standard siren observations from Voyager and NEMO is still promising. For example, using bright sirens from Voyager and NEMO can measure the Hubble constant with a precision of about $2\%$ and $6\%$ respectively, and using the Voyager-NEMO network can improve the precision to about $1.6\%$. Moreover, bright sirens can be used to break the degeneracy of cosmological parameters generated by CMB data, and to a certain extent, 2.5G detectors can also play a role in this aspect. Observations of dark sirens by 2.5G detectors can achieve relatively good results in measuring the Hubble constant, with a precision of within $2\%$, and if combining observations of bright and dark sirens, the precision of the Hubble constant measurement can reach about $1.4\%$. Finally, we also discussed the impact of the uncertainty in the binary neutron star merger rate on the estimation of cosmological parameters. We conclude that the magnificent prospect for solving the Hubble tension is worth expecting in the era of the 2.5G ground-based GW detectors.
description: 28 pages, 13 figures
A holistic pathway to biosensor translation
Creators: name: D'Alton, Laena
name: Souto, DEP
name: Punyadeera, C
name: Abbey, Brian
name: Voelcker, NH
name: Hogan, Conor
name: Moraes Silva, Saimon
Publisher: name: La Trobe
Year: 2024
Subjects: classificationCode: 42
subject: Health sciences
subject: FOS: Health sciences
classificationCode: 46
subject: Information and computing sciences
classificationCode: 4203
subject: Health services and systems
classificationCode: 320602
subject: Medical biotechnology diagnostics (incl. biosensors)

description: Point-of-care (POC) biosensors have enormous potential to help guide and inform clinical decisions at a patient's location. They are particularly relevant to underserved populations, and people living in remote locations where healthcare infrastructure and resources are often limited. The translation of effective POC biosensors into commercial products is rapidly growing across many research fields. A significant quantity of scientific articles focused on the fundamental, applied, and proof-of-concept aspects of biosensing are reported each year. However, this extensive body of work is not reflected in the comparatively small number of commercial biosensors available on the market. Here, we discuss key aspects of the biosensor translation process including the selection of analytical biomarkers in various body fluids, clinical trials, regulatory approval, consumer engagement, manufacturing and scale-up strategies, health economics, and legal and ethical considerations.