cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Sense representations for Portuguese: experiments with sense embeddings and deep neural language models
Creators: name: da Silva, Jessica Rodrigues
name: Caseli, Helena de Medeiros
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computation and Language (cs.CL)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Sense representations have gone beyond word representations like Word2Vec, GloVe and FastText and achieved innovative performance on a wide range of natural language processing tasks. Although very useful in many applications, the traditional approaches for generating word embeddings have a strict drawback: they produce a single vector representation for a given word ignoring the fact that ambiguous words can assume different meanings. In this paper, we explore unsupervised sense representations which, different from traditional word embeddings, are able to induce different senses of a word by analyzing its contextual semantics in a text. The unsupervised sense representations investigated in this paper are: sense embeddings and deep neural language models. We present the first experiments carried out for generating sense embeddings for Portuguese. Our experiments show that the sense embedding model (Sense2vec) outperformed traditional word embeddings in syntactic and semantic analogies task, proving that the language resource generated here can improve the performance of NLP tasks in Portuguese. We also evaluated the performance of pre-trained deep neural language models (ELMo and BERT) in two transfer learning approaches: feature based and fine-tuning, in the semantic textual similarity task. Our experiments indicate that the fine tuned Multilingual and Portuguese BERT language models were able to achieve better accuracy than the ELMo model and baselines.
description: 24 pages, Springer Nature
Dark Pulse Emission of A Fiber Laser
Creators: name: Zhang, H.
name: Tang, D. Y.
name: Zhao, L. M.
name: Wu, X.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Optics (physics.optics)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We report on the dark pulse emission of an all-normal dispersion erbium-doped fiber laser with a polarizer in cavity. We found experimentally that apart from the bright pulse emission, under appropriate conditions the fiber laser could also emit single or multiple dark pulses. Based on numerical simulations we interpret the dark pulse formation in the laser as a result of dark soliton shaping.
description: 16 pages
title: Sex and Censorship in Art
titleType: Subtitle
title: Revista de História da Arte (15)
Creators: name: Marques, Bruno
name: Rodrigues, Érica
name: Duarte, Miguel
Publisher: name: Instituto de História da Arte, Faculdade de Ciências Sociais e Humanas, Universidade Nova de Lisboa
Year: 2020

description: Este número da Revista de História da Arte apresenta um conjunto de artigos com o objetivo de contribuir para a compreensão do modo como a censura ao erotismo e à explicitação da sexualidade, em diferentes contextos e geografias, tem influenciado a criação, a circulação, a exibição e a interpretação das obras de arte, definidas no contexto alargado da interação entre diversas forças e fenómenos políticos, institucionais e socio-históricos.
description: Marques, B., Rodrigues, E. F., Duarte, M. M. (Eds.) (2020). Sex and Censorship in Art. Revista de História da Arte (15). ISSN: 1646-1762. https://institutodehistoriadaarte.com/publications/rha/revista-de-historia-da-arte-n-o-15-2020/
D4.1: Initial results on adaptive directional LOS and NLOS reliable connectivity
Creators: name: Di Renzo, Marco
name: Aravanis, Alexis
name: Qian, Xuewen
name: Hrasnica, Halid
name: Ntontin, Konstantinos
name: Katzouris, Nikos
name: Manganaris, Kyriakos
name: Lazarakis, Fotis
name: Alexiou, Angeliki
name: Boulogeorgos, Alexandros‐Apostolos A.
name: Kokkoniemi, Joonas
name: He, Jiguang
name: Yaqub, Edwin
name: Desai, Rachana
name: Halmetoja, Heikki
name: Sanguanpuak, Tachporn
Publisher: name: Zenodo
Year: 2021
Subjects: Reconfigurable intelligent surfaces, D‐band

description: The present deliverable summarizes the initial results on the development of tailored techniques for the adaptive directional LOS and NLOS reliable connectivity in RIS‐assisted communication systems that operate in high frequency bands, i.e., above 100 GHz. The RIS‐assisted systems are conducive, if not necessary, for the compensation of the attenuation in high frequency bands that are highly susceptible to blockages. In this course, the present deliverable focuses on the challenges arising by the dynamic movement of users or access points in the flexible environment shaped by the presence of RISs and D‐band systems and the challenges pertaining to the blockages of the D‐band links. In particular, it focuses on the employment of adaptive (stochastic and machine learning) tools for the development of appropriate physical layer approaches and of medium access protocols that can support, for instance, in the presence of blockages, highly focused beams and /or beamforming protocols for the two links between the transmitter / receiver and the RIS.
Multiple Andreev reflections in topological insulator nanoribbons
Creators: name: Kim, Rak-Hee
name: Kim, Nam-Hee
name: Kim, Bongkeon
name: Hou, Yasen
name: Yu, Dong
name: Doh, Yong-Joo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Superconducting proximity junctions made of topological insulator (TI) nanoribbons (NRs) provide a useful platform for studying topological superconductivity. We report on the fabrication and measurement of Josephson junctions (JJs) using Sb doped Bi$_2$Se$_3$ NRs in contact with Al electrodes. Aharonov$-$Bohm and Altshuler$-$Aronov$-$Spivak oscillations of the axial magneto-conductance of TI NR were observed, indicating the existence of metallic surface states along the circumference of the TI NR. We observed the supercurrent in the TI NR JJ and subharmonic gap structures of the differential conductance due to multiple Andreev reflections. The interface transparency of the TI NR JJs estimated based on the excess current reaches $τ$ = 0.83, which is among the highest values reported for TI JJs. The temperature dependence of critical current is consistent with the short and ballistic junction model confirming the formation of highly transparent superconducting contacts on the TI NR. Our observations would be useful for exploring topological Josephson effects in TI NRs.
description: 15 pages, 3 figures
Adapting Learned Sparse Retrieval for Long Documents
Creators: name: Nguyen, Thong
name: MacAvaney, Sean
name: Yates, Andrew
Publisher: name: arXiv
Year: 2023
Subjects: subject: Information Retrieval (cs.IR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Learned sparse retrieval (LSR) is a family of neural retrieval methods that transform queries and documents into sparse weight vectors aligned with a vocabulary. While LSR approaches like Splade work well for short passages, it is unclear how well they handle longer documents. We investigate existing aggregation approaches for adapting LSR to longer documents and find that proximal scoring is crucial for LSR to handle long documents. To leverage this property, we proposed two adaptations of the Sequential Dependence Model (SDM) to LSR: ExactSDM and SoftSDM. ExactSDM assumes only exact query term dependence, while SoftSDM uses potential functions that model the dependence of query terms and their expansion terms (i.e., terms identified using a transformer's masked language modeling head). Experiments on the MSMARCO Document and TREC Robust04 datasets demonstrate that both ExactSDM and SoftSDM outperform existing LSR aggregation approaches for different document length constraints. Surprisingly, SoftSDM does not provide any performance benefits over ExactSDM. This suggests that soft proximity matching is not necessary for modeling term dependence in LSR. Overall, this study provides insights into handling long documents with LSR, proposing adaptations that improve its performance.
description: SIGIR 2023
Small curvature laminations in hyperbolic 3-manifolds
Creators: name: Breslin, William
Publisher: name: arXiv
Year: 2009
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics

description: We show that if $\mathcal{L}$ is a codimension-one lamination in a finite volume hyperbolic 3-manifold such that the principal curvatures of each leaf of $\mathcal{L}$ are all in the interval $(-δ,δ)$ for a fixed $δ\in[0,1)$ and no complimentary region of $\mathcal{L}$ is an interval bundle over a surface, then each boundary leaf of $\mathcal{L}$ has a nontrivial fundamental group. We also prove existence of a fixed constant $δ_0 > 0$ such that if $\mathcal{L}$ is a codimension-one lamination in a finite volume hyperbolic 3-manifold such that the principal curvatures of each leaf of $\mathcal{L}$ are all in the interval $(-δ_0 ,δ_0)$ and no complimentary region of $\mathcal{L}$ is an interval bundle over a surface, then each boundary leaf of $\mathcal{L}$ has a noncyclic fundamental group.
description: 8 pages, 1 figure
An approach to the organization of knowledge for the modelling of conversation
Creators: name: McCalla, Gordon Irvine
Publisher: name: University of British Columbia
Year: 2010

description: Presented is a description of an approach to the modelling of conversation. It is suggested that to have any hope of succeeding at this endeavour, the problem must be tackled principally as a problem in pragmatics rather than as one in language analysis alone. Several pragmatic aspects of conversation are delineated and it is shown that the attempt to account for them raises a number of general issues in the representation of knowledge. A scheme for resolving some of these issues is constructed and given computational description as a set of (non-implemented) LISP-based control structures called |LISP. Central to this scheme are several different types of object that encode knowledge and communicate this knowledge by passing messages. One particular kind of object, the pattern expression (|PEXPR), turns out to be the most versatile. (|PEXPR) can encode an arbitrary amount of procedural or declarative information; are capable, as a by-product of their message passing behaviour of providing both a context for future processing decisions and a record of past processing decisions; and make contributions to the resolution of several artificial intelligence problems. A model of conversation is then proposed and some examples of typical conversations that might occur in the general context of attending a symphony concert are detailed in |LISP. It is suggested that conversation is goal oriented behaviour; and, in fact, the model is presented in terms of level of goal: from higher level non-linguistic goals through scripts directing both sides of a conversation, speech acts guiding one conversant's actions, and, finally, language level goals providing a basic parsing component for the model. In addition, a place is delineated for belief models of the conversants, necessary if utterances are to be properly understood or produced. The embedding of this kind of language model in a |LISP base yields a rich pragmatic environment for analyzing conversation.
A quantum interface between light and nuclear spins in quantum dots
Creators: name: Schwager, Heike
name: Cirac, J. Ignacio
name: Giedke, Géza
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The coherent coupling of flying photonic qubits to stationary matter-based qubits is an essential building block for quantum communication networks. We show how such a quantum interface can be realized between a traveling-wave optical field and the polarized nuclear spins in a singly charged quantum dot strongly coupled to a high-finesse optical cavity. By adiabatically eliminating the electron a direct effective coupling is achieved. Depending on the laser field applied, interactions that enable either write-in or read-out are obtained.
description: 10 pages, 5 figures, final version
A quantum description of bubble growth in a superheated fluid
Creators: name: Choi, S.
name: Galdamez, K. M.
name: Sundaram, B.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We discuss a quantum description of bubble growth in a superheated liquid Helium by addressing the problem of operator ordering ambiguities that arise due to the presence of position dependent mass (PDM) in this system. Using a supersymmetric quantum mechanics formalism along with the Weyl quantization rule, we are able to identify specific operator orderings for this problem. This is a general method which should be applicable to other PDM systems.
description: 1 Figure. To be published in Phys. Lett A. v3: Updated abstract and significant changes from v2, in particular inclusion of a new section on Weyl transform
Electrically-controllable RKKY interaction in semiconductor quantum wires
Creators: name: Zhu, Jia-Ji
name: Chang, Kai
name: Liu, Ren-Bao
name: Lin, Hai-Qing
Publisher: name: arXiv
Year: 2009
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We demonstrate in theory that it is possible to all-electrically manipulate the RKKY interaction in a quasi-one-dimensional electron gas embedded in a semiconductor heterostructure, in the presence of Rashba and Dresselhaus spin-orbit interaction. In an undoped semiconductor quantum wire where intermediate excitations are gapped, the interaction becomes the short-ranged Bloembergen-Rowland super-exchange interaction. Owing to the interplay of different types of spin-orbit interaction, the interaction can be controlled to realize various spin models, e.g., isotropic and anisotropic Heisenberg-like models, Ising-like models with additional Dzyaloshinsky-Moriya terms, by tuning the external electric field and designing the crystallographic directions. Such controllable interaction forms a basis for quantum computing with localized spins and quantum matters in spin lattices.
description: 5 pages, 1 figure
Conformal Wavefunctions for Graviton Amplitudes
Creators: name: Liu, Chang
name: Lowe, David A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The extended-BMS algebra of asymptotically flat spacetime contains an SO(3,1) subgroup that acts by conformal transformations on the celestial sphere. It is of interest to study the representations of this subgroup associated with gravitons. To reduce the equation of motion to a Schrodinger-like equation it is necessary to impose a non-covariant gauge condition. Using these solutions, leading-order gauge invariant Weyl scalars are then computed and decomposed into families of unitary principal series representations. An invertible holographic mapping is constructed between these unitary principal series operators and massless spin-2 perturbations of flat spacetime.
description: 16 pages
Galaxy assembly bias and large-scale distribution: a comparison between IllustrisTNG and a semi-analytic model
Creators: name: Hadzhiyska, Boryana
name: Liu, Sonya
name: Somerville, Rachel S.
name: Gabrielpillai, Austen
name: Bose, Sownak
name: Eisenstein, Daniel
name: Hernquist, Lars
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In this work, we compare large scale structure observables for stellar mass selected samples at $z=0$, as predicted by two galaxy models, the hydrodynamical simulation IllustrisTNG and the Santa-Cruz semi-analytic model (SC-SAM). Although both models have been independently calibrated to match observations, rather than each other, we find good agreement between the two models for two-point clustering and galaxy assembly bias signatures. The models also show a qualitatively similar response of occupancy and clustering to secondary halo paramaters other than mass, such as formation history and concentration, although with some quantitative differences. Thus, our results demonstrate that the galaxy-halo relationships in SC-SAM and TNG are quite similar to first order. However, we also find areas in which the models differ. For example, we note a strong correlation between halo gas content and environment in TNG, which is lacking in the SC-SAM, as well as differences in the occupancy predictions for low-mass haloes. Moreover, we show that higher-order statistics, such as cumulants of the density field, help to accurately describe the galaxy distribution and discriminate between models that show degenerate behavior for two-point statistics. Our results suggest that SAMs are a promising cost-effective and intuitive method for generating mock catalogues for next generation cosmological surveys.
description: 20 pages, 12 plots, 2 appendices, submitted to MNRAS for review
Nyctophilus Leach 1821
Creators: name: Parnaby, Harry E.
name: King, Andrew G.
name: Eldridge, Mark D. B.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Chiroptera
Vespertilionidae
Nyctophilus

description: Genus Nyctophilus Leach, 1821
 Type species. Nyctophilus geoffroyi Leach, 1821.
description: Published as part of Parnaby, Harry E., King, Andrew G. & Eldridge, Mark D. B., 2021, A New Bat Species from Southwestern Western Australia, Previously Assigned to Gould's Long-eared Bat Nyctophilus gouldi Tomes, 1858, pp. 53-66 in Records of the Australian Museum (Rec. Aust. Mus.) (Rec. Aust. Mus.) 73 (1) on page 60, DOI: 10.3853/j.2201-4349.73.2021.1766, http://zenodo.org/record/5412323
Black Hole Production of Monopoles in the Early Universe
Creators: name: Das, Saurav
name: Hook, Anson
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the early universe, evaporating black holes heat up the surrounding plasma and create a temperature profile around the black hole that can be more important than the black hole itself. As an example, we demonstrate how the hot plasma surrounding evaporating black holes can efficiently produce monopoles via the Kibble-Zurek mechanism. In the case where black holes reheat the universe, reheat temperatures above $\sim 500$ GeV can already lead to monopoles overclosing the universe.
description: 22 pages, 2 figures
Random walk in genome space : A key ingredient of intermittent dynamics of community assembly on evolutionary time scales
Creators: name: Murase, Yohsuke
name: Shimada, Takashi
name: Ito, Nobuyasu
name: Rikvold, Per Arne
Publisher: name: arXiv
Year: 2010
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: Community assembly is studied using individual-based multispecies models. The models have stochastic population dynamics with mutation, migration, and extinction of species. Mutants appear as a result of mutation of the resident species, while migrants have no correlation with the resident species. It is found that the dynamics of community assembly with mutations are quite different from the case with migrations. In contrast to mutation models, which show intermittent dynamics of quasi-steady states interrupted by sudden reorganizations of the community, migration models show smooth and gradual renewal of the community. As a consequence, instead of the $1/f$ diversity fluctuations found for the mutation models, $1/f^2$, random-walk like fluctuations are observed for the migration models. In addition, a characteristic species-lifetime distribution is found: a power law that is cut off by a "skewed" distribution in the long-lifetime regime. The latter has a longer tail than a simple exponential function, which indicates an age-dependent species-mortality function. Since this characteristic profile has been observed, both in fossil data and in several other mathematical models, we conclude that it is a universal feature of macroevolution.
Caldararu's conjecture and Tsygan's formality
Creators: name: Calaque, Damien
name: Rossi, Carlo A.
name: Bergh, Michel Van den
Publisher: name: arXiv
Year: 2009
Subjects: subject: Algebraic Geometry (math.AG)
subject: K-Theory and Homology (math.KT)
subject: FOS: Mathematics
subject: 14F99, 14D99

description: In this paper we complete the proof of Caldararu's conjecture on the compatibility between the module structures on differential forms over poly-vector fields and on Hochschild homology over Hochschild cohomology. In fact we show that twisting with the square root of the Todd class gives an isomorphism of precalculi between these pairs of objects. Our methods use formal geometry to globalize the local formality quasi-isomorphisms introduced by Kontsevich and Shoikhet (the existence of the latter was conjectured by Tsygan). We also rely on the fact - recently proved by the first two authors - that Shoikhet's quasi-isomorphism is compatible with cap product after twisting with a Maurer-Cartan element.
description: 48 pages, 2 figures; a number of additional explanations added (suggested by the referees)
Quiver flag varieties and multigraded linear series
Creators: name: Craw, Alastair
Publisher: name: arXiv
Year: 2009
Subjects: subject: Algebraic Geometry (math.AG)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics

description: This paper introduces a class of smooth projective varieties that generalise and share many properties with partial flag varieties of type A. The quiver flag variety M_\vartheta(Q,r) of a finite acyclic quiver Q (with a unique source) and a dimension vector r is a fine moduli space of stable representations of Q. Quiver flag varieties are Mori Dream Spaces, they are obtained via a tower of Grassmann bundles, and their bounded derived category of coherent sheaves is generated by a tilting bundle. We define the multigraded linear series of a weakly exceptional sequence of locally free sheaves E = (O_X,E_1,...,E_ρ) on a projective scheme X to be the quiver flag variety |E| = M_\vartheta(Q,r) of a pair (Q,r) encoded by E. When each E_i is globally generated, we obtain a morphism ϕ_|E| : X -> |E| realising each E_i as the pullback of a tautological bundle. As an application we introduce the multigraded Plucker embedding of a quiver flag variety
description: 23 pages. Final version includes minor changes, to appear in Duke Math Journal
Orientability in Yang-Mills Theory over Nonorientable Surfaces
Creators: name: Ho, Nan-Kuo
name: Liu, Chiu-Chu Melissa
name: Ramras, Daniel A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Symplectic Geometry (math.SG)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53D30, 53C07

description: In arXiv:math/0605587, the first two authors have constructed a gauge-equivariant Morse stratification on the space of connections on a principal U(n)-bundle over a connected, closed, nonorientable surface. This space can be identified with the real locus of the space of connections on the pullback of this bundle over the orientable double cover of this nonorientable surface. In this context, the normal bundles to the Morse strata are real vector bundles. We show that these bundles, and their associated homotopy orbit bundles, are orientable for any n when the nonorientable surface is not homeomorphic to the Klein bottle, and for n<4 when the nonorientable surface is the Klein bottle. We also derive similar orientability results when the structure group is SU(n).
description: 49 pages, 3 figures
CP violation in mixing and oscillations for leptogenesis II: the highly degenerate case
Creators: name: Racker, J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We extend to the highly degenerate case a recent approach for analyzing the sources of CP violation in baryogenesis models with quasi-degenerate neutrinos. In this approach an expansion of the resummed propagator around the poles is plugged into a quantum field theory model of neutrino oscillations and a source term for the time evolution of the lepton asymmetry is built directly from the probabilities of lepton number violating processes involving only stable particles. This allows for a transparent consideration of unitarity requirements. The source term has contributions that can be identified with CP violation from mixing, oscillations and interference between both. For the highly degenerate case, i.e. when the mass difference between two neutrinos is similar or smaller than their decay widths, we find that in general the mixing and oscillation terms contribute with opposite signs to the generation of lepton asymmetry and the contribution of the interference term is typically very relevant and crucial to ensure unitarity is satisfied. Moreover, the expressions we obtain are finite in the double degenerate limit of equal masses and couplings. The calculations are done in a simple scalar toy model.
description: 14 pages, 3 figures
Two-dimensional fermionic superfluids, pairing instability and vortex liquids in the absence of time reversal symmetry
Creators: name: Nikolic, Predrag
Publisher: name: arXiv
Year: 2009
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We consider a generic two-dimensional system of fermionic particles with attractive interactions and no disorder. If time-reversal symmetry is absent, it is possible to obtain incompressible insulating states in addition to the superfluid at zero temperature. The superfluid-insulator phase transition is found to be second order in type-II systems using a perturbative analysis of Cooper pairing instability in quantum Hall states of unpaired fermions. We obtain the pairing phase diagram as a function of chemical potential (density) and temperature. However, a more careful analysis presented here reveals that the pairing quantum phase transition is always preempted by another transition into a strongly correlated normal state which retains Cooper pairing and cannot be smoothly connected to the quantum Hall state of unpaired fermions. Such a normal phase can be qualitatively viewed as a liquid of vortices, although it may acquire conventional broken symmetries. Even if it did not survive at finite temperatures its influence would be felt through strong quantum fluctuations below a crossover temperature scale. These conclusions directly apply to fermionic ultra-cold atom systems near unitarity, but are likely relevant for the properties of other strongly correlated superfluids as well, including high temperature superconductors.
description: 11 pages, 3 figures, published version
Angular momentum, spinors and twistors
Creators: name: Helfer, Adam D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Twistors appear to provide a satisfactory treatment of angular momentum for gravitationally radiating systems. The approach is manifestly Bondi-Metzner-Sachs (BMS) invariant, and there are no supertranslation ambiguities. The resulting definitions of center of mass and spin are appealing: unphysical contributions from bad cuts are canceled off from the center of mass, and the spin appears formally as a displacement of the center of mass into the complex. For transitions between asymptotically Minkowskian regimes (non-radiative regimes with purely electric Bondi shear), when there is no supertranslation offset (equivalently, radation memory) between the regimes the results are in agreement with those deducible from other approaches. However, when there is an offset, the results are different. The twistor-derived change-of-origin formula is closely parallel to the special-relativistic one, with an algebraic cross-product between the energy-momentum and a direction-dependent translation derived from the supertranslation. (No supermomenta appear.) There is also a "longitudinal" contribution to the emitted angular momentum (one sensitive to the total energy-momentum and not just the emitted energy-momentum), and terms which are both linear and cubic in the gravitational radiation (whereas BMS-based definitions give purely quadratic contributions). The first-order terms mean that the supertranslation offsets can contribute to the exchange of angular momentum with gravitational radiation, even in weak-field limits. This is illustrated with a simple almost-special-relativistic model.
description: 27 pages, to appear in PRD
STARRED: a two-channel deconvolution method with Starlet regularization
Creators: name: Michalewicz, Kevin
name: Millon, Martin
name: Dux, Frédéric
name: Courbin, Frédéric
Publisher: name: arXiv
Year: 2023
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The spatial resolution of astronomical images is limited by atmospheric turbulence and diffraction in the telescope optics, resulting in blurred images. This makes it difficult to accurately measure the brightness of blended objects because the contributions from adjacent objects are mixed in a time-variable manner due to changes in the atmospheric conditions. However, this effect can be corrected by characterizing the Point Spread Function (PSF), which describes how a point source is blurred on a detector. This function can be estimated from the stars in the field of view, which provides a natural sampling of the PSF across the entire field of view. Once the PSF is estimated, it can be removed from the data through the so-called deconvolution process, leading to images of improved spatial resolution. The deconvolution operation is an ill-posed inverse problem due to noise and pixelization of the data. To solve this problem, regularization is necessary to guarantee the robustness of the solution. Regularization can take the form of a sparse prior, meaning that the recovered solution can be represented with only a few basis eigenvectors. STARRED is a Python package developed in the context of the COSMOGRAIL collaboration and applies to a vast variety of astronomical problems. It proposes to use an isotropic wavelet basis, called Starlets, to regularize the solution of the deconvolution problem. This family of wavelets has been shown to be well-suited to represent astronomical objects. STARRED provides two modules to first reconstruct the PSF, and then perform the deconvolution. It is based on two key concepts: i) the image is reconstructed in two separate channels, one for the point sources and one for the extended sources, and ii) the code relies on the deliberate choice of not completely removing the effect of the PSF, but rather bringing the image to a higher resolution.
Eighteen Years of Kilonova Discoveries with Swift
Creators: name: Troja, Eleonora
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Swift has now completed 18 years of mission, during which it discovered thousands of gamma-ray bursts (GRBs) as well as new classes of high-energy transient phenomena. Its first breakthrough result was the localization of short duration GRBs, which enabled for redshift measurements and kilonova searches. Swift, in synergy with the Hubble Space Telescope and a wide array of ground-based telescopes, provided the first tantalizing evidence of a kilonova in the aftermath of a short GRB. In 2017, Swift observations of the gravitational wave event GW170817 captured the early UV photons from the kilonova AT2017gfo, opening a new window into the physics of kilonovae. Since then, Swift has continued to expand the sample of known kilonovae, leading to the surprising discovery of a kilonova in a long duration GRB. This article will discuss recent advances in the study of kilonovae driven by the fundamental contribution of Swift.
description: 26 pages, 7 figures, 2 tables. Published as part of the Special Issue "18 Years of Science with the Neil Gehrels Swift Observatory's Ultra-Violet/Optical Telescope"
The effect of asymmetric beams in the Wilkinson Microwave Anisotropy Probe experiment
Creators: name: Wehus, Ingunn Kathrine
name: Ackerman, Lotty
name: Eriksen, H. K.
name: Groeneboom, Nicolaas E.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We generate simulations of the CMB temperature field as observed by the WMAP satellite, taking into account the detailed shape of the asymmetric beams and scanning strategy of the experiment, and use these to re-estimate the WMAP beam transfer functions. This method avoids the need of artificially symmetrizing the beams, as done in the baseline WMAP approach, and instead measures the total convolution effect by direct simulation. We find only small differences with respect to the nominal transfer functions, typically less than 1% everywhere, and less than 0.5% at l<400. The net effect on the CMB power spectrum is less than 0.6%. The effect on all considered cosmological parameters are negligible. For instance, we find that the spectral index of scalar perturbations after taking into account the beam asymmetries is n_s = 0.964 +- 0.014, corresponding to a negative shift of -0.1 sigma compared to the previously released WMAP results. Our CMB sky simulations are made publicly available, and can be used for general studies of asymmetric beam effects in the WMAP data.
description: 14 pages, 7 figures, published version
Credit risk premia and quadratic BSDEs with a single jump
Creators: name: Ankirchner, Stefan
name: Blanchet-Scalliet, Christophette
name: Eyraud-Loisel, Anne
Publisher: name: arXiv
Year: 2009
Subjects: subject: Pricing of Securities (q-fin.PR)
subject: Probability (math.PR)
subject: Computational Finance (q-fin.CP)
subject: FOS: Economics and business
subject: FOS: Mathematics

description: This paper is concerned with the determination of credit risk premia of defaultable contingent claims by means of indifference valuation principles. Assuming exponential utility preferences we derive representations of indifference premia of credit risk in terms of solutions of Backward Stochastic Differential Equations (BSDE). The class of BSDEs needed for that representation allows for quadratic growth generators and jumps at random times. Since the existence and uniqueness theory for this class of BSDEs has not yet been developed to the required generality, the first part of the paper is devoted to fill that gap. By using a simple constructive algorithm, and known results on continuous quadratic BSDEs, we provide sufficient conditions for the existence and uniqueness of quadratic BSDEs with discontinuities at random times.
Formation of photosynthetic and grain yield of spring barley (Hordeum vulgare L.) depend on varietal characteristics and plant growth regulators
Creators: name: Panfilova, A.
name: Korkhova, M.
name: Gamayunova, V.
name: Fedorchuk, M.
name: Drobitko, A.
name: Nikonchuk, N.
name: Kovalenko, O.
Publisher: name: Agronomy Research
Year: 2019
Subjects: spring barley
variety
plant nutrition
leaf area
photosynthetic potential
pure photosynthesis productivity
article

description: The aim of the study was to determine the efficiency of the barley treatment crops with modern retrograde preparations on the background of the mineral fertilizers introduction into the photosynthetic activity of crops and grain yield. The experiments were carried out in 2013 -2017 on the southern black soil in the conditions of the Ukrainian Steppe. On the basis of the study results, it was determined that the introduction of irrigated fertilizer barley in a dose of N30P30 (background) under pre-sowing cultivation and the application of extra-root crop supplements at the phases beginning of the barley outflow straw into the tube and the organoleptic fermentation of Organic D2 and natural microbial complex Escort - Bio creates favorable conditions for the formation at the optimal levels of photosynthetic parameters and grain yield. Thus, on average, over the years of research and by factor variety, grain yield on these experimental variants was 3.37–3.41 t ha-1 , which exceeded its level on uncontrolled control by 0.71–0.75 t ha-1 or 26.7–28.2%. Based on the study results, the use of modern regenerating agents against the background of mineral fertilizers can be recommended as an expedient and effective measure of spring barley raising the productivity.
More on Lensing by a Cosmological Constant
Creators: name: Ishak, Mustapha
name: Rindler, Wolfgang
name: Dossett, Jason
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The question of whether or not the cosmological constant affects the bending of light around a concentrated mass has been the subject of some recent papers. We present here a simple, specific and transparent example where $Λ$ bending clearly takes place, and where it is clearly neither a coordinate effect nor an aberration effect. We then show that in some recent works using perturbation theory the $Λ$ contribution was missed because of initial too-stringent smallness assumptions. Namely: Our method has been to insert a Kottler (Schwarzschild with $Λ$) vacuole into a Friedmann universe, and to calculate the total bending within the vacuole. We assume that no more bending occurs outside. It is important to observe that while the mass contribution to the bending takes place mainly quite near the lens, the $Λ$ bending continues throughout the vacuole. Thus if one deliberately restricts one's search for $Λ$ bending to the immediate neighborhood of the lens, one will not find it. Lastly, we show that the $Λ$ bending also follows from standard Weyl focusing, and so again, it cannot be a coordinate effect.
description: 5 pages, matches MNRAS accepted version
Coulomb Force as an Entropic Force
Creators: name: Wang, Tower
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Motivated by Verlinde's theory of entropic gravity, we give a tentative explanation to Coulomb's law with an entropic force. When trying to do this, we find the equipartition rule should be extended to charges and the concept of temperature should be reinterpreted. If one accepts the holographic principle as well as our generalizations and reinterpretations, then Coulomb's law, the Poisson equation and the Maxwell equations can be derived smoothly. Our attempt can be regarded as a new way to unify the electromagnetic force with gravity, from the entropic origin. Possibly some of our postulates are related to the D-brane picture of black hole thermodynamics.
description: discussion and bibliography updated
Distinguishing Random and Black Hole Microstates
Creators: name: Kudler-Flam, Jonah
name: Narovlansky, Vladimir
name: Ryu, Shinsei
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: This is an expanded version of the short report [Phys. Rev. Lett. 126, 171603 (2021)], where the relative entropy was used to distinguish random states drawn from the Wishart ensemble as well as black hole microstates. In this work, we expand these ideas by computing many generalizations including the Petz Rényi relative entropy, sandwiched Rényi relative entropy, fidelities, and trace distances. These generalized quantities are able to teach us about new structures in the space of random states and black hole microstates where the von Neumann and relative entropies were insufficient. We further generalize to generic random tensor networks where new phenomena arise due to the locality in the networks. These phenomena sharpen the relationship between holographic states and random tensor networks. We discuss the implications of our results on the black hole information problem using replica wormholes, specifically the state dependence (hair) in Hawking radiation. Understanding the differences between Hawking radiation of distinct evaporating black holes is an important piece of the information problem that was not addressed by entropy calculations using the island formula. We interpret our results in the language of quantum hypothesis testing and the subsystem eigenstate thermalization hypothesis (ETH), deriving that chaotic (including holographic) systems obey subsystem ETH for all subsystems less than half the total system size.
description: 57 pages
Planetary Nebulae Detected in the Spitzer Space Telescope GLIMPSE II Legacy Survey
Creators: name: Zhang, Yong
name: Kwok, Sun
Publisher: name: arXiv
Year: 2009
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We report the result of a search for the infrared counterparts of 37 planetary nebulae (PNs) and PN candidates in the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire II (GLIMPSE II) survey. The photometry and images of these PNs at 3.6, 4.5, 5.8, 8.0, and 24mum, taken through the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer for Spitzer (MIPS), are presented. Most of these nebulae are very red and compact in the IRAC bands, and are found to be bright and extended in the 24mum band. The infrared morphology of these objects are compared with Ha images of the Macquarie-AAO-Strasbourg (MASH) and MASH II PNs. The implications for morphological difference in different wavelengths are discussed. The IRAC data allow us to differentiate between PNs and HII regions and be able to reject non-PNs from the optical catalogue (e.g., PNG 352.1-00.0). Spectral energy distributions (SEDs) are constructed by combing the IRAC and MIPS data with existing near-, mid-, and far-IR photometry measurements. The anomalous colors of some objects allow us to infer the presence of aromatic emission bands. These multi-wavelength data provide useful insights into the nature of different nebular components contributing to the infrared emission of PNs.
description: 48 pages, 53 figures (Figures 2-43 are available on the ApJ website or on request from the authors), accepted for publication in ApJ
Uniform bounds for norms of sums of independent random functions
Creators: name: Goldenshluger, Alexander
name: Lepski, Oleg
Publisher: name: arXiv
Year: 2009
Subjects: subject: Probability (math.PR)
subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: In this paper, we develop a general machinery for finding explicit uniform probability and moment bounds on sub-additive positive functionals of random processes. Using the developed general technique, we derive uniform bounds on the ${\mathbb{L}}_s$-norms of empirical and regression-type processes. Usefulness of the obtained results is illustrated by application to the processes appearing in kernel density estimation and in nonparametric estimation of regression functions.
description: Published in at http://dx.doi.org/10.1214/10-AOP595 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Towards Generalised Half-Duplex Systems
Creators: name: Di Giusto, Cinzia
name: Guizouarn, Loïc Germerie
name: Lozes, Etienne
Publisher: name: arXiv
Year: 2021
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: FIFO automata are finite state machines communicating through FIFO queues. They can be used for instance to model distributed protocols. Due to the unboundedness of the FIFO queues, several verification problems are undecidable for these systems. In order to model-check such systems, one may look for decidable subclasses of FIFO systems. Binary half-duplex systems are systems of two FIFO automata exchanging over a half-duplex channel. They were studied by Cece and Finkel who established the decidability in polynomial time of several properties. These authors also identified some problems in generalising half-duplex systems to multi-party communications. We introduce greedy systems, as a candidate to generalise binary half-duplex systems. We show that greedy systems retain the same good properties as binary half-duplex systems, and that, in the setting of mailbox communications, greedy systems are quite closely related to a multiparty generalisation of half-duplex systems.
description: In Proceedings ICE 2021, arXiv:2109.14908
Number operator-annihilation operator uncertainty as an alternative of the number-phase uncertainty relation
Creators: name: Urizar-Lanz, Inigo
name: Toth, Geza
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider a number operator-annihilation operator uncertainty as a well behaved alternative to the number-phase uncertainty relation, and examine its properties. We find a formulation in which the bound on the product of uncertainties depends on the expectation value of the particle number. Thus, while the bound is not a constant, it is a quantity that can easily be controlled in many systems. The uncertainty relation is approximately saturated by number-phase intelligent states. This allows us to define amplitude squeezing, connecting coherent states to Fock states, without a reference to a phase operator. We propose several setups for an experimental verification.
description: 8 pages including 3 figures, revtex4; v2: typos corrected, presentation improved; v3: presentation considerably extended; v4: published version
Meta-Regression Analysis of Errors in Short-Term Electricity Load Forecasting
Creators: name: Hopf, Konstantin
name: Hartstang, Hannah
name: Staake, Thorsten
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Forecasting electricity demand plays a critical role in ensuring reliable and cost-efficient operation of the electricity supply. With the global transition to distributed renewable energy sources and the electrification of heating and transportation, accurate load forecasts become even more important. While numerous empirical studies and a handful of review articles exist, there is surprisingly little quantitative analysis of the literature, most notably none that identifies the impact of factors on forecasting performance across the entirety of empirical studies. In this article, we therefore present a Meta-Regression Analysis (MRA) that examines factors that influence the accuracy of short-term electricity load forecasts. We use data from 421 forecast models published in 59 studies. While the grid level (esp. individual vs. aggregated vs. system), the forecast granularity, and the algorithms used seem to have a significant impact on the MAPE, bibliometric data, dataset sizes, and prediction horizon show no significant effect. We found the LSTM approach and a combination of neural networks with other approaches to be the best forecasting methods. The results help practitioners and researchers to make meaningful model choices. Yet, this paper calls for further MRA in the field of load forecasting to close the blind spots in research and practice of load forecasting.
description: 8 pages, 3 figures, 7 tables