cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Before-after safety analysis of a shared space implementation
Creators: name: Orsini, Federico
name: Batista, Mariana
name: Friedrich, Bernhard
name: Gastaldi, Massimiliano
name: Rossi, Riccardo
Publisher: name: arXiv
Year: 2023
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Shared spaces aim to reduce the dominance of motor vehicles by promoting pedestrian and cyclist activity and minimizing segregation between road users. Despite the intended scope to improve the safety of vulnerable road users, only few works in the literature focused on before after safety evaluations, mainly analyzing changes in users trajectories and speeds, traffic volumes, and conflict counts, which, while useful, cannot univocally quantify road safety. Here, we propose a more advanced methodology, based on surrogate measures of safety and Extreme Value Theory, to assess road safety before and after the implementation of a shared space. The aim is to produce a crash risk estimation in different scenarios, obtaining a quantitative and comprehensive indicator, useful to practitioners for evaluating the safety of urban design solutions. A real world case study illustrates the proposed procedure. Video data were collected on two separate days, before and after a shared space implementation, and were semiautomatically processed to extract road users trajectories. Analysis of traffic volumes, trajectories, speeds and yield ratios allowed to understand the spatial behavior of road users in the two scenarios. Traffic conflicts, identified with an innovative surrogate measure of safety called time to avoided collision point, TTAC, were then used to estimate a Lomax distribution, and therefore to model the probabilistic relationship between conflicts and crashes, eventually retrieving a crash risk estimate. Results show that the analyzed shared space was able to significantly reduce the risk of crashes, and these findings are consistent with the observed changes in users speed and spatial behavior. The analyzed case study and its limitations were useful in highlighting the methodology main features and suggesting practical prescriptions for practitioners.
description: This is the Accepted Manuscript version. The version of record of this manuscript has been published and is available on Case Studies on Transport Policy, Volume 13, 101021
Homologie polygraphique des systèmes locaux
Creators: name: Guetta, Léonard
name: Maltsiniotis, Georges
Publisher: name: arXiv
Year: 2023
Subjects: subject: Algebraic Topology (math.AT)
subject: Category Theory (math.CT)
subject: FOS: Mathematics
subject: 18G10, 18G15, 18G35, 18G90, 18N30, 18N40, 18N50, 18N65, 55N10, 55N25, 55U10, 55U15

description: In this article, we introduce a notion of polygraphic homology of a strict $ω$-category with coefficients in a local system, generalizing the polygraphic homology with coefficients in $\mathbb Z$, introduced by François Métayer. We show that the homology of a simplicial set with coefficients in a local system coincides with the polygraphic homology of its image by the left adjoint of the Street nerve with coefficients in the corresponding local system. We define in this framework a comparison morphism between the polygraphic homology of a strict $ω$-category and the homology of its Street nerve, and we show that this morphism is an isomorphism for (1-)categories. This is not true for an arbitrary $ω$-category. Nevertheless, we conjecture that for an analogous construction in the framework of weak $ω$-categories ``à la Grothendieck'' we would always obtain an isomorphism.
description: 56 pages, in French language. Minor corrections
Risk concentration under second order regular variation
Creators: name: Das, Bikramjit
name: Kratz, Marie
Publisher: name: arXiv
Year: 2017
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60G70, 60E05, 62E20, 62P05, 91B30

description: Measures of risk concentration and their asymptotic behavior for portfolios with heavy-tailed risk factors is of interest in risk management. Second order regular variation is a structural assumption often imposed on such risk factors to study their convergence rates. In this paper, we provide the asymptotic rate of convergence of the measure of risk concentration for a portfolio of heavy-tailed risk factors, when the portfolio admits the so-called second order regular variation property. Moreover, we explore the relationship between multivariate second order regular variation for a vector (e.g., risk factors) and the second order regular variation property for the sum of its components (e.g., the portfolio of risk factors). Results are illustrated with a variety of examples.
description: 24 pages
On aspherical configuration Lie groupoids
Creators: name: Roushon, S K
Publisher: name: arXiv
Year: 2023
Subjects: subject: Algebraic Topology (math.AT)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: Primary: 22A22, 55P20, 55R80, Secondary: 57R18

description: The complement of the hyperplanes $\{x_i=x_j\}$, for all $i\neq j$ in $M^n$, for $M$ an aspherical $2$-manifold, is known to be aspherical. Here we consider the situation, when $M$ is a $2$-dimensional orbifold. We prove this complement to be aspherical for a class of aspherical $2$-dimensional orbifolds, and predict that it should be true in general also. We generalize this question in the category of Lie groupoids, as orbifolds can be identified with a certain kind of Lie groupoids.
description: 14p. arXiv admin note: substantial text overlap with arXiv:2106.08110
Independence role in the generalized Sznajd model
Creators: name: Azhari
name: Muslim, Roni
name: Mulya, Didi Ahmad
name: Indrayani, Heni
name: Wicaksana, Cakra Adipura
name: Rizki, Akbar
Publisher: name: arXiv
Year: 2023
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: The Sznajd model is one of sociophysics's well-known opinion dynamics models. Based on social validation, it has found application in diverse social systems and remains an intriguing subject of study, particularly in scenarios where interacting agents deviate from prevailing norms. This paper investigates the generalized Sznajd model, featuring independent agents on a complete graph and a two-dimensional square lattice. Agents in the network act independently with a probability $p$, signifying a change in their opinion or state without external influence. This model defines a paired agent size $r$, influencing a neighboring agent size $n$ to adopt their opinion. This study incorporates analytical and numerical approaches, especially on the complete graph. Our results show that the macroscopic state of the system remains unaffected by the neighbor size $n$ but is contingent solely on the number of paired agents $r$. Additionally, the time required to reach a stationary state is inversely proportional to the number of neighboring agents $n$. For the two-dimensional square lattice, two critical points $p = p_c$ emerge based on the configuration of agents. The results indicate that the universality class of the model on the complete graph aligns with the mean-field Ising universality class. Furthermore, the universality class of the model on the two-dimensional square lattice, featuring two distinct configurations, is identical and falls within the two-dimensional Ising universality class.
description: 14 pages, 10 figures
Estrategias de Formación enfocadas en la Experiencia del Usuario
Creators: name: Sena, Priscila
Publisher: name: Zenodo
Year: 2024

description: Presentación visual utilizada para la ponencia de mismo nombre, realizada el 21 de agosto de 2024 en el Congreso Internacional de Bibliotecas y Unidades de Información (CIBIC 2024), en la ciudad de Bogotá/Colombia.
Birational geometry of moduli spaces of configurations of points on the line
Creators: name: Bolognesi, Michele
name: Massarenti, Alex
Publisher: name: arXiv
Year: 2017
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14D22, 14H10, 14H37 (Primary), 14N05, 14N10, 14N20 (Secondary)

description: In this paper we study the geometry of GIT configurations of $n$ ordered points on $\mathbb{P}^1$ both from the the birational and the biregular viewpoint. In particular, we prove that any extremal ray of the Mori cone of effective curves of the quotient $(\mathbb{P}^1)^n//PGL(2)$, taken with the symmetric polarization, is generated by a one dimensional boundary stratum of the moduli space. Furthermore, we develop some technical machinery that we use to compute the canonical divisor and the Hilbert polynomial of $(\mathbb{P}^1)^n//PGL(2)$ in its natural embedding, and its group of automorphisms.
description: 22 pages (fixed one small inaccuracy)
Design of 5G Full Dimension Massive MIMO Systems
Creators: name: Nadeem, Qurrat-Ul-Ain
name: Kammoun, Abla
name: Debbah, Mérouane
name: Alouini, and Mohamed-Slim
Publisher: name: arXiv
Year: 2016
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Massive multiple-input-multiple-output (MIMO) transmission is a promising technology to improve the capacity and reliability of wireless systems. However, the number of antennas that can be equipped at a base station (BS) is limited by the BS form factor, posing a challenge to the deployment of massive linear arrays. To cope with this limitation, this work discusses Full Dimension MIMO (FD-MIMO), which is currently an active area of research and standardization in the 3rd Generation Partnership Project (3GPP) for evolution towards fifth generation (5G) cellular systems. FD-MIMO utilizes an active antenna system (AAS) with a 2D planar array structure, which provides the ability of adaptive electronic beamforming in the 3D space. This paper presents the design of the AAS and the ongoing efforts in the 3GPP to develop the corresponding 3D channel model. Compact structure of large-scale antenna arrays drastically increases the spatial correlation in FD-MIMO systems. In order to account for its effects, the generalized spatial correlation functions for channels constituted by individual antenna elements and overall antenna ports in the AAS are derived. Exploiting the quasi-static channel covariance matrices of the users, the problem of determining the optimal downtilt weight vector for antenna ports, which maximizes the minimum signal-to-interference ratio of a multi-user multiple-input-single-output system, is formulated as a fractional optimization problem. A quasi-optimal solution is obtained through the application of semi-definite relaxation and Dinkelbach's method. Finally, the user-group specific elevation beamforming scenario is devised, which offers significant performance gains as confirmed through simulations. These results have direct application in the analysis of 5G FD-MIMO systems.
Source-Replacement Model for Phase-Matching Quantum Key Distribution
Creators: name: Huang, Yizhi
name: Du, Zhenyu
name: Ma, Xiongfeng
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum key distribution has emerged as a promising solution for constructing secure communication networks, offering information-theoretic security guaranteed by the principles of quantum mechanics. One of the most advanced quantum key distribution protocols to date is the phase-matching protocol. Its security was initially established using an abstract method known as symmetry-protected privacy. In this study, we reevaluate the security of the phase-matching protocol using an intuitive source-replacement model, and we arrive at conclusions that align with the original proof. This model provides a fresh perspective on the protocol's security. As an application of this approach, we introduce a beam-splitting attack scheme. Leveraging the source-replacement model, we derive a lower bound on the phase error rate under this attack, further underscoring the robustness of our security analysis method.
description: 14 pages, 4 figures
Initial perturbations dependence of non-equilibrium continuous and discontinuous pattern transition
Creators: name: Ishikawa, Rikuya
name: Kurita, Rei
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: A phase separation in a spatially heterogeneous environment is closely related to intracellular science and material science. For the phase separation, initial heterogeneous perturbations play an important role in pattern formations. In this study, a pattern transition from a lamellar pattern to a columnar pattern is investigated in the presence of a slit pattern as the initial perturbations. Here it is found that the transition behavior depends on the initial slit width. When the initial slit width is close to the width of the columnar pattern at the steady state, the pattern transition is the second-order-like (continuous) transition. Meanwhile, the pattern transition becomes the first-order-like (discontinuous) transition if the width of the initial slit is much larger than that at the steady state. Then those transition behaviors can be explained by the dynamical path during the pattern formation. This finding will advance understanding of the initial perturbation dependence of nonequilibrium phenomena.
Passive Query-Recovery Attack Against Secure Conjunctive Keyword Search Schemes
Creators: name: Dijkslag, Marco
name: Damie, Marc
name: Hahn, Florian
name: Peter, Andreas
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: While storing documents on the cloud can be attractive, the question remains whether cloud providers can be trusted with storing private documents. Even if trusted, data breaches are ubiquitous. To prevent information leakage one can store documents encrypted. If encrypted under traditional schemes, one loses the ability to perform simple operations over the documents, such as searching through them. Searchable encryption schemes were proposed allowing some search functionality while documents remain encrypted. Orthogonally, research is done to find attacks that exploit search and access pattern leakage that most efficient schemes have. One type of such an attack is the ability to recover plaintext queries. Passive query-recovery attacks on single-keyword search schemes have been proposed in literature, however, conjunctive keyword search has not been considered, although keyword searches with two or three keywords appear more frequently in online searches. We introduce a generic extension strategy for existing passive query-recovery attacks against single-keyword search schemes and explore its applicability for the attack presented by Damie et al. (USENIX Security '21). While the original attack achieves up to a recovery rate of 85% against single-keyword search schemes for an attacker without exact background knowledge, our experiments show that the generic extension to conjunctive queries comes with a significant performance decrease achieving recovery rates of at most 32%. Assuming a stronger attacker with partial knowledge of the indexed document set boosts the recovery rate to 85% for conjunctive keyword queries with two keywords and achieves similar recovery rates as previous attacks by Cash et al. (CCS '15) and Islam et al. (NDSS '12) in the same setting for single-keyword search schemes.
description: Published in ACNS 2022
Unsteady electrorotation of a drop in a constant electric field
Creators: name: Tyatyushkin, Alexander N.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The unsteady electrorotation of a drop of a viscous weakly conducting polarizable liquid suspended in another viscous weakly conducting polarizable liquid immiscible with the former in an applied constant uniform electric field is theoretically investigated. The surface tension of the drop is regarded as sufficiently large for deformation of the drop under the action of the applied electric field and the electrohydrodynamic flow can be considered small and the drop can be considered spherical in the calculation of the electric field and flow. The electric field intensity and the velocity and pressure in the electrohydrodynamic flow are sought for in the form of a series solution with time-dependent scalar, vector, and tensor coefficients for which relations are found allowing one to determine them. The coefficients are sought for in the form of asymptotic expansions over the parameter, the smallness of which corresponds to the sufficiently large viscosity of the drop with respect to that of the surrounding liquid. The differential equations for the terms of the dimensionless expansions up to the first and second orders with respect to this parameter are obtained. Their stationary solutions are found in the explicit form and their stability is investigated. Up to the terms of the second order, transitions to deformational oscillations of the drop are established not to occur.
description: 14 pages, 6 figures; the revision resulted from the publication process
Interacting dark energy model in the brane scenario: A Dynamical System Analysis
Creators: name: Biswas, Sujay Kr.
name: Chakraborty, Subenoy
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: The present work is a second in the series of investigation of the background dynamics in brane cosmology when dark energy is coupled to dark matter by a suitable interaction. Here, dark matter is chosen in the form of perfect fluid with barotropic equation of state while a real scalar field with self interacting potential is chosen as dark energy. The scalar field potential is chosen as exponential or hyperbolic in nature and three different choices for the interaction between the dark species are considered. In the background of spatially flat, homogeneous and isotropic Friedmann-Robertson-Walker (FRW) brane model, the evolution equations are reduced to an autonomous system by suitable transformation of variables and a series of critical points are obtained for different interactions. By analyzing the critical points, we have found cosmologically viable model describing an early inflationary scenario to dark energy dominated era connecting through a matter dominated phase.
description: 26 pages, 11 captioned figures. Version is accepted for publication in IJGMMP
Decentralization of Energy Systems with Blockchain: Bridging Top-down and Bottom-up Management of the Electricity Grid
Creators: name: Mishra, Sakshi
name: Khatami, Roohallah
name: Chen, Yu Christine
Publisher: name: arXiv
Year: 2023
Subjects: subject: Systems and Control (eess.SY)
subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: For more than a century, the grid has operated in a centralized top-down fashion. However, as distributed energy resources (DERs) penetration grows, the grid edge is increasingly infused with intelligent computing and communication capabilities. Thus, the bottom-up approach to grid operations inclined toward decentralizing energy systems will likely gain momentum alongside the existing centralized paradigm. Decentralization refers to transferring control and decision-making from a centralized entity (individual, organization, or group thereof) to a distributed network. It is not a new concept - in energy systems context or otherwise. In the energy systems context, however, the complexity of this multifaceted concept increases manifolds due to two major reasons - i) the nature of the commodity being traded (the electricity) and ii) the enormity of the traditional electricity sector's structure that builds, operates, and maintains this capital-intensive network. In this work, we aim to highlight the need for and outline a credible path toward restructuring the current operational architecture of the electricity grid in view of the ongoing decentralization trends with an emphasis on peer-to-peer energy trading. We further introduce blockchain technology in the context of decentralized energy systems problems. We also suggest that blockchain is an effective technology for facilitating the synergistic operations of top-down and bottom-up approaches to grid management.
description: 9 pages, 1 Figure. arXiv admin note: text overlap with arXiv:2112.09756
Development of a digital model of a stationary hydrogen storage tank based on room temperature (TiFe) hydride
Creators: name: Puszkiel, Julián
Publisher: name: Zenodo
Year: 2024

description: In this work, the digital twin of an existing solid-state hydrogen storage tank is developed by applying the finite elements method (FEM). The hydrogen storage tank contains a pelletized room temperature alloy (TiFeMn) as hydride forming material. To build the digital twin, the kinetic, thermodynamic, and intrinsic relationships are determined using experimental and mathematical methods to mimic the behavior of the real tank. Theoretical and experimental approaches allow comparing the obtained model with the experimental results of the real tank. Moreover, the hydride bed's operative conditions and geometrical characteristics are optimized to improve the performance of the hydrogen storage device. As a result, it is found that the simulative results mimic the behavior of the real tank quite well. In the case of the parameters optimization, it is found that a variation of the operating pressure and the coolant temperature had a predominantly linear trend, but limitations with respect to the pressure could be worked out for the desorption. The variation of the coolant velocity is highly efficacious up to 2 m/s. However, a further increase of the coolant velocity does not improve the tank's performance notably. The geometry optimization is carried out by varying the number of pelletized hydride material keeping the total mass of material constant. It is found that increasing the number of pellets has a positive effect on the reaction process, but this does not show a proportional trend. The development of the digital model and the optimization analyses result in a deeper understanding of transport phenomena at a large scale, identifying the optimal operative conditions for the current design and proposing improvements to the current design.
Explicit universal bounds for squeezing functions of ($\mathbb{C}$-)convex domains
Creators: name: Bharali, Gautam
name: Nikolov, Nikolai
Publisher: name: arXiv
Year: 2023
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 32F45 (Primary) 32F32 (Secondary)

description: We prove two separate lower bounds -- one for nondegenerate convex domains and the other for nondegenerate $\mathbb{C}$-convex (but not necessarily convex) domains -- for the squeezing function that hold true for all domains in $\mathbb{C}^n$, for a fixed $n\geq 2$, of the stated class. We provide explicit expressions in terms of $n$ for these estimates.
description: 8 pages; added new references, a discussion on pp. 7,8 on the strictness of the inequalities in Theorems 1.1 and 1.2, and a question (Question 4.2 on p. 8)
Heavy-light $N+1$ clusters of two-dimensional fermions
Creators: name: Givois, J.
name: Tononi, A.
name: Petrov, D. S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We study binding of $N$ identical heavy fermions by a light atom in two dimensions assuming zero-range attractive heavy-light interactions. By using the mean-field theory valid for large $N$ we show that the $N+1$ cluster is bound when the mass ratio exceeds $1.074N^2$. The mean-field theory, being scale invariant in two dimensions, predicts only the shapes of the clusters leaving their sizes and energies undefined. By taking into account beyond-mean-field effects we find closed-form expressions for these quantities. We also discuss differences between the Thomas-Fermi and Hartree-Fock approaches for treating the heavy fermions.
description: 11 pages, 3 figures
On the Hilbert geometry of simplicial Tits sets
Creators: name: Nie, Xin
Publisher: name: arXiv
Year: 2011
Subjects: subject: Differential Geometry (math.DG)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 20F67, 51F15, 53C60

description: The moduli space of convex projective structures on a simplicial hyperbolic Coxeter orbifold is either a point or the real line. Answering a question of M. Crampon, we prove that in the latter case, when one goes to infinity in the moduli space, the entropy of the Hilbert metric tends to 0.
description: 18 pages, 5 figures
Latent Computational Complexity of Symmetry-Protected Topological Order with Fractional Symmetry
Creators: name: Miller, Jacob
name: Miyake, Akimasa
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: An emerging insight is that ground states of symmetry-protected topological orders (SPTO's) possess latent computational complexity in terms of their many-body entanglement. By introducing a fractional symmetry of SPTO, which requires the invariance under 3-colorable symmetries of a lattice, we prove that every renormalization fixed-point state of 2D $(\mathbb{Z}_2)^m$ SPTO with fractional symmetry can be utilized for universal quantum computation using only Pauli measurements, as long as it belongs to a nontrivial 2D SPTO phase. Our infinite family of fixed-point states may serve as a base model to demonstrate the idea of a "quantum computational phase" of matter, whose states share universal computational complexity ubiquitously.
description: 17 pages, 4 figures. v2: published version, contains a new appendix dealing with renormalization methods
Analyzing the 21-cm signal brightness temperature in the Universe with inhomogeneities
Creators: name: Pandey, Shashank Shekhar
name: Halder, Ashadul
name: Majumdar, A. S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We explore the 21-cm signal in our Universe containing inhomogeneous matter distribution at considerably large scales. Employing Buchert's averaging procedure in the context of a model of spacetime with multiple inhomogeneous domains, we evaluate the effect of our model parameters on the observable 21-cm signal brightness temperature. Our model parameters are constrained through the Markov Chain Monte Carlo method using the Union 2.1 supernova Ia observational data. We find that a significant dip in the brightness temperature compared to the $Λ$CDM prediction could arise as an effect of the inhomogeneities present in the Universe.
description: 18 pages, 8 figures, 2 appendices
The quasi-Poisson Goldman formula
Creators: name: Nie, Xin
Publisher: name: arXiv
Year: 2013
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53D30

description: We prove a quasi-Poisson bracket formula for the space of representations of the fundamental groupoid of a surface with boundary, which generalizes Goldman's Poisson bracket formula. We also deduce a similar formula for quasi-Poisson cross-sections.
CINECA Risk Management Registry D8.2
Creators: name: Keane, Thomas
Publisher: name: Zenodo
Year: 2019
Subjects: Risk
Register
CINECA

description: The Purpose of the CINECA Risk Register is to provide the Project Management Team with a list of risks identified, stated clearly and assessed as to their importance to meeting project objectives. The identification of mitigations for identified risks in the risk register will
 facilitate risk handling, should a risk be triggered. The Coordinator and Work Package Leaders, as well as the project manager, will regularly review the Risk Register and update it when necessary.
Observation of a Modulational Instability in Bose-Einstein condensates
Creators: name: Everitt, P. J.
name: Sooriyabandara, M. A.
name: Guasoni, M.
name: Wigley, P. B.
name: Wei, C. H.
name: McDonald, G. D.
name: Hardman, K. S.
name: Manju, P.
name: Close, J. D.
name: Kuhn, C. C. N.
name: Szigeti, S. S.
name: Kivshar, Y. S.
name: Robins, N. P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We observe the breakup dynamics of an elongated cloud of condensed $^{85}$Rb atoms placed in an optical waveguide. The number of localized spatial components observed in the breakup is compared with the number of solitons predicted by a plane-wave stability analysis of the nonpolynomial nonlinear Schrödinger equation, an effective one-dimensional approximation of the Gross-Pitaevskii equation for cigar-shaped condensates. It is shown that the numbers predicted from the fastest growing sidebands are consistent with the experimental data, suggesting that modulational instability is the key underlying physical mechanism driving the breakup.
description: 6 pages, 5 figures
Localization of soft modes at the depinning transition
Creators: name: Cao, Xiangyu
name: Bouzat, Sebastian
name: Kolton, Alejandro B.
name: Rosso, Alberto
Publisher: name: arXiv
Year: 2017
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We characterize the soft modes of the dynamical matrix at the depinning transition, and compare it with the properties of the Anderson model (and long--range generalizations). The density of states at the edge of the spectrum displays a universal linear tail, different from the Lifshitz tails. The eigenvectors are instead very similar in the two matrix ensembles. We focus on the ground state (soft mode), which represents the epicenter of avalanche instabilities. We expect it to be localized in all finite dimensions, and make a clear connection between its localization length and the Larkin length of the depinning model. In the fully connected model, the weak--strong pinning transition coincides with a peculiar localization transition of the ground state.
description: Revised Section V with new Figure; 18 pages, 14 figures
Observational constraints on early dark energy
Creators: name: McDonough, Evan
name: Hill, J. Colin
name: Ivanov, Mikhail M.
name: La Posta, Adrien
name: Toomey, Michael W.
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: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We review and update constraints on the Early Dark Energy (EDE) model from cosmological data sets, in particular Planck PR3 and PR4 cosmic microwave background (CMB) data and large-scale structure (LSS) data sets including galaxy clustering and weak lensing data from the Dark Energy Survey, Subaru Hyper Suprime-Cam, and KiDS+VIKING-450, as well as BOSS/eBOSS galaxy clustering and Lyman-$α$ forest data. We detail the fit to CMB data, and perform the first analyses of EDE using the CAMSPEC and Hillipop likelihoods for Planck CMB data, rather than Plik, both of which yield a tighter upper bound on the allowed EDE fraction than that found with Plik. We then supplement CMB data with large-scale structure data in a series of new analyses. All these analyses are concordant in their Bayesian preference for $Λ$CDM over EDE, as indicated by marginalized posterior distributions. We perform a series of tests of the impact of priors in these results, and compare with frequentist analyses based on the profile likelihood, finding qualitative agreement with the Bayesian results. All these tests suggest prior volume effects are not a determining factor in analyses of EDE. This work provides both a review of existing constraints and several new analyses.
description: 59 pages, 23 figures, 11 tables, Invited review for International Journal of Modern Physics D
REPÚBLICA COMPLACENTE OU MONARQUIA RELUTANTE: A CONSTITUIÇÃO FRAGILIZADA
Creators: name: Santana, José Cláudio Pavão
Publisher: name: Zenodo
Year: 2023
Subjects: CONSTITUIÇÃO
REPÚBLICA
MONARQUIA
RELUTÂNCIA

description: 1. Introdução. 2. A Constituição. 3. A identidade constitucional. 4. A Constituição pactuada. 5. A Constituição alcançada. 6. Observância aos compromissos. 7. Conclusão.
Analysis for satellite-based high-dimensional extended B92 and high-dimensional BB84 quantum key distribution
Creators: name: Dutta, Arindam
name: Muskan
name: Banerjee, Subhashish
name: Pathak, Anirban
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A systematic analysis of the advantages and challenges associated with the satellite-based implementation of the high dimensional extended B92 (HD-Ext-B92) and high-dimensional BB84 (HD-BB84) protocol is analyzed. The method used earlier for obtaining the key rate for the HD-Ext-B92 is modified here and subsequently the variations of the key rate, probability distribution of key rate (PDR), and quantum bit error rate (QBER) with respect to dimension and noise parameter of a depolarizing channel is studied using the modified key rate equation. Further, the variations of average key rate (per pulse) with zenith angle and link length in different weather conditions in day and night considering extremely low noise for dimension d=32 are investigated using elliptic beam approximation. The effectiveness of the HD-(extended) protocols used here in creating satellite-based quantum key distribution links (both up-link and down-link) is established by appropriately modeling the atmosphere and analyzing the variation of average key rates with the probability distribution of the transmittance (PDT). The analysis performed here has revealed that in higher dimensions, HD-BB84 outperforms HD-Ext-B92 in terms of both key rate and noise tolerance. However, HD-BB84 experiences a more pronounced saturation of QBER in high dimensions.
description: Satellite Quantum Communication, High-Dimensional Quantum Key Distribution, Elliptical Beam Approximation, LEO Satellite
Lassa virus Z protein hijacks the autophagy machinery for efficient transportation by interrupting CCT2-mediated cytoskeleton network formation
Creators: name: Yuan, Yueming
name: Fang, An
name: Zhang, Mai
name: Zhou, Ming
name: Fu, Zhen F.
name: Zhao, Ling
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biophysics
subject: Biochemistry
subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Cell Biology
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: The Lassa virus (LASV) is a widely recognized virulent pathogen that frequently results in lethal viral hemorrhagic fever (VHF). Earlier research has indicated that macroautophagy/autophagy plays a role in LASV replication, but, the precise mechanism is unknown. In this present study, we show that LASV matrix protein (LASV-Z) is essential for blocking intracellular autophagic flux. LASV-Z hinders actin and tubulin folding by interacting with CCT2, a component of the chaperonin-containing T-complexes (TRiC). When the cytoskeleton is disrupted, lysosomal enzyme transit is hampered. In addition, cytoskeleton disruption inhibits the merge of autophagosomes with lysosomes, resulting in autophagosome accumulation that promotes the budding of LASV virus-like particles (VLPs). Inhibition of LASV-Z-induced autophagosome accumulation blocks the LASV VLP budding process. Furthermore, it is found that glutamine at position 29 and tyrosine at position 48 on LASV-Z are important in interacting with CCT2. When these two sites are mutated, LASV-mut interacts with CCT2 less efficiently and can no longer inhibit the autophagic flux. These findings demonstrate a novel strategy for LASV-Z to hijack the host autophagy machinery to accomplish effective transportation. Abbreviation: 3-MA: 3-methyladenine; ATG5: autophagy related 5; ATG7: autophagy related 7; Baf-A1: bafilomycin A1; CCT2: chaperonin containing TCP1 subunit 2; co-IP: co-immunoprecipitation; CTSD: cathepsin D; DAPI: 4’,6-diamidino-2’-phenylindole; DMSO: dimethyl sulfoxide; EGFR: epidermal growth factor receptor; GFP: green fluorescent protein; hpi: hours post-infection; hpt: hours post-transfection; LAMP1: lysosomal-associated membrane protein 1; LASV: lassa virus; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; mCherry: red fluorescent protein; PM: plasma membrane; SQSTM1/p62: sequestosome 1; STX6: syntaxin 6; VLP: virus-like particle; TEM: transmission electron microscopy; TRiC: chaperonin-containing T-complex; WB: western blotting; μm: micrometer; μM: micromole.
Charged gravastar model in $f(T)$ gravity admitting conformal motion
Creators: name: Bhar, Piyali
name: Rej, Pramit
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences
subject: 83C20, 83D05, 85A15

description: In this paper, model of charged gravastar under $f(T)$ modified gravity is obtained. The model has been explored by taking the diagonal tetrad field of static spacetime together with electric charge. To solve the Einstein-Maxwell field equations, along with $f(T)$ gravity, we assume the existence of a conformal Killing vector which relates between geometry and matter through the Einstein-Maxwell field equations by an inheritance symmetry. We study several cases of interest to explore physically valid features of the solutions. Some physical properties of the model are discussed and we match our interior spacetime to the exterior Reissner-Nordström spacetime in presence of thin shell.
description: 15 pages
On optimal control of reflected diffusions
Creators: name: Jonsson, Adam
Publisher: name: arXiv
Year: 2023
Subjects: subject: Probability (math.PR)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: We study a simple singular control problem for a Brownian motion with constant drift and variance reflected at the origin. Exerting control pushes the process towards the origin and generates a concave increasing state-dependent yield which is discounted at a fixed rate. The most interesting feature of the problem is that its solution can be more complicated than anticipated. Indeed, for some parameter values, the optimal policy involves two reflecting barriers and one repelling boundary, the action region being the union of two disjoint intervals. We also show that the apparent anomaly can be understood as involving a switch between two strategies with different risk profiles: The risk-neutral decision maker initially gambles on the more risky strategy, but lowers risk if this strategy underperforms.
Entropy degeneration of convex projective surfaces
Creators: name: Nie, Xin
Publisher: name: arXiv
Year: 2015
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics

description: We show that the volume entropy of the Hilbert metric on a closed convex projective surface tends to zero as the corresponding Pick differential tends to infinity. The proof is based on the theorem, due to Benoist and Hulin, that the Hilbert metric and Blaschke metric are comparable.
description: 5 pages
Multiple tunable real-space degeneracies in graphene irradiated by twisted light
Creators: name: Aich, Suman
name: Seradjeh, Babak
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report the theoretical discovery of multiple real-space degenerate Floquet-Bloch states in monolayer graphene coherently driven by twisted circularly-polarized light. Using Floquet theory, we characterize the real-space structure of quasienergies and Floquet modes in terms of the orbital angular momentum and radial vortex profile of light. We obtain the effective real-space Floquet Hamiltonian and show it supports crossings of Floquet modes, especially at high-symmetry $K$ and $Γ$ points of graphene, localized at rings around the vortex center. At specific frequencies, the vortex bound states form a multiply degenerate structure in real-space. This structure is purely dynamically generated and controlled by the frequency and tuned by the intensity of twisted light. We discuss the experimental feasibility of observing and employing multiple real-space degeneracies for coherent optoelectronic quantum state engineering.
description: 6 figures, published version
S-folds and 4d N=3 superconformal field theories
Creators: name: Aharony, Ofer
name: Tachikawa, Yuji
name: Gomi, Kiyonori
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: S-folds are generalizations of orientifolds in type IIB string theory, such that the geometric identifications are accompanied by non-trivial S-duality transformations. They were recently used by Garcia-Etxebarria and Regalado to provide the first construction of four dimensional N=3 superconformal theories. In this note, we classify the different variants of these N=3 preserving S-folds, distinguished by an analog of discrete torsion, using both a direct analysis of the different torsion classes and the compactification of the S-folds to three dimensional M-theory backgrounds. Upon adding D3-branes, these variants lead to different classes of N=3 superconformal field theories. We also analyze the holographic duals of these theories, and in particular clarify the role of discrete gauge and global symmetries in holography. In the main part of the paper, certain properties of cohomology groups associated to the S-folds were conjectured and used. This arXiv version includes an appendix written by Kiyonori Gomi in 2023 providing the proofs of the required properties using the technique of Borel equivariant cohomology, whose brief review is also provided.
description: 29 pages + 19 pages; v3: a mathematical appendix was provided by Kiyonori Gomi
Klt varieties with trivial canonical class -- Holonomy, differential forms, and fundamental groups
Creators: name: Greb, Daniel
name: Guenancia, Henri
name: Kebekus, Stefan
Publisher: name: arXiv
Year: 2017
Subjects: subject: Algebraic Geometry (math.AG)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 14J32, 14E30, 32J27

description: We investigate the holonomy group of singular Kähler-Einstein metrics on klt varieties with numerically trivial canonical divisor. Finiteness of the number of connected components, a Bochner principle for holomorphic tensors, and a connection between irreducibility of holonomy representations and stability of the tangent sheaf are established. As a consequence, known decompositions for tangent sheaves of varieties with trivial canonical divisor are refined. In particular, we show that up to finite quasi-étale covers, varieties with strongly stable tangent sheaf are either Calabi-Yau or irreducible holomorphic symplectic. These results form one building block for Höring-Peternell's recent proof of a singular version of the Beauville-Bogomolov Decomposition Theorem.
description: v4: final version, to appear in Geometry & Topology; v5: filled small gap in the proof of Cor. 7.4
Singularities of the hyperbolic elastic flow: Convergence, quantization and blow-ups
Creators: name: Schlierf, Manuel
Publisher: name: arXiv
Year: 2023
Subjects: subject: Analysis of PDEs (math.AP)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53E40, 35B40, 35A21 (MSC2020)

description: We study the elastic flow of closed curves and of open curves with clamped boundary conditions in the hyperbolic plane. While global existence and convergence toward critical points for initial data with sufficiently small energy is already known, this study pioneers an investigation into the flow's singular behavior. We prove a convergence theorem without assuming smallness of the initial energy, coupled with a quantification of potential singularities: Each singularity carries an energy cost of at least 8. Moreover, the blow-ups of the singularities are explicitly classified. A further contribution is an explicit understanding of the singular limit of the elastic flow of $λ$-figure-eights, a class of curves that previously served in showing sharpness of the energy threshold 16 for the smooth convergence of the elastic flow of closed curves.
description: Revised version, 28 pages
Optimized Clustering Estimators for BAO Measurements Accounting for Significant Redshift Uncertainty
Creators: name: Ross, Ashley J.
name: Banik, Nilanjan
name: Avila, Santiago
name: Percival, Will J.
name: Dodelson, Scott
name: Garcia-Bellido, Juan
name: Crocce, Martin
name: Elvin-Poole, Jack
name: Giannantonio, Tommaso
name: Manera, Marc
name: Sevilla-Noarbe, Ignacio
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We determine an optimized clustering statistic to be used for galaxy samples with significant redshift uncertainty, such as those that rely on photometric redshifts. To do so, we study the baryon acoustic oscillation (BAO) information content as a function of the orientation of galaxy clustering modes with respect to their angle to the line-of-sight (LOS). The clustering along the LOS, as observed in a redshift-space with significant redshift uncertainty, has contributions from clustering modes with a range of orientations with respect to the true LOS. For redshift uncertainty $σ_z \geq 0.02(1+z)$ we find that while the BAO information is confined to transverse clustering modes in the true space, it is spread nearly evenly in the observed space. Thus, measuring clustering in terms of the projected separation (regardless of the LOS) is an efficient and nearly lossless compression of the signal for $σ_z \geq 0.02(1+z)$. For reduced redshift uncertainty, a more careful consideration is required. We then use more than 1700 realizations (combining two separate sets) of galaxy simulations mimicking the Dark Energy Survey Year 1 sample to validate our analytic results and optimized analysis procedure. We find that using the correlation function binned in projected separation, we can achieve uncertainties that are within 10 per cent of those predicted by Fisher matrix forecasts. We predict that DES Y1 should achieve a 5 per cent distance measurement using our optimized methods. We expect the results presented here to be important for any future BAO measurements made using photometric redshift data.
description: Matches version accepted by MNRAS, should be clearer
$L^2$ well-posedness of boundary value problems for parabolic systems with measurable coefficients
Creators: name: Auscher, Pascal
name: Egert, Moritz
name: Nyström, Kaj
Publisher: name: arXiv
Year: 2016
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics

description: We prove the first positive results concerning boundary value problems in the upper half-space of second order parabolic systems only assuming measurability and some transversal regularity in the coefficients of the elliptic part. To do so, we introduce and develop a first order strategy by means of a parabolic Dirac operator at the boundary to obtain, in particular, Green's representation for solutions in natural classes involving square functions and non-tangential maximal functions, well-posedness results with data in $L^2$-Sobolev spaces together with invertibility of layer potentials, and perturbation results. In the way, we solve the Kato square root problem for parabolic operators with coefficients of the elliptic part depending measurably on all variables. The major new challenge, compared to the earlier results by one of us under time and transversally independence of the coefficients, is to handle non-local half-order derivatives in time which are unavoidable in our situation.
description: Upload of the published version