cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Composition series of arbitrary cardinality in modular lattices and abelian categories
Creators: name: Hanson, Eric J.
name: Rock, J. Daisie
Publisher: name: arXiv
Year: 2021
Subjects: subject: Category Theory (math.CT)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: Primary: 06C05, 18E10. Secondary: 16G20, 18B35, 55N31

description: For a certain family of complete modular lattices, we prove a Jordan--Hölder--Scheier-like" theorem with no assumptions on cardinality or well-orderedness. This family includes both lattices which are both join- and meet-continuous, as well as the lattices of subobjects of any object in an abelian category satisfying properties related to Grothendieck's axioms (AB5) and (AB5*). We then give several examples of objects in abelian categories which satisfy these axioms, including pointwise finite-dimensional persistence modules, presheaves, and certain Prüfer modules. Moreover, we show that, over an arbitrary ring, the infinite product of isomorphic simple modules both fails to satisfy our axioms and admits at least two composition series with distinct cardinalities. We conclude by giving a lattice-theoretic proof that any object which is locally finitely generated and satisfies our axioms can be expressed as a direct sum of indecomposable subobjects. We conjecture that this decomposition is unique.
description: journal version, substantial updates from v1 (including change to title, generalization to the setting of modular lattices, and discussion of direct sum decompositions)
Explaining Black-Box Models through Counterfactuals
Creators: name: Altmeyer, Patrick
name: van Deursen, Arie
name: Liem, Cynthia C. S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Programming Languages (cs.PL)
subject: FOS: Computer and information sciences

description: We present CounterfactualExplanations.jl: a package for generating Counterfactual Explanations (CE) and Algorithmic Recourse (AR) for black-box models in Julia. CE explain how inputs into a model need to change to yield specific model predictions. Explanations that involve realistic and actionable changes can be used to provide AR: a set of proposed actions for individuals to change an undesirable outcome for the better. In this article, we discuss the usefulness of CE for Explainable Artificial Intelligence and demonstrate the functionality of our package. The package is straightforward to use and designed with a focus on customization and extensibility. We envision it to one day be the go-to place for explaining arbitrary predictive models in Julia through a diverse suite of counterfactual generators.
description: 13 pages, 9 figures, originally published in The Proceedings of the JuliaCon Conferences (JCON)
The fate of stringy AdS vacua and the WGC
Creators: name: Danielsson, Ulf
name: Dibitetto, Giuseppe
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The authors of arXiv:1610.01533 have recently proposed a stronger version of the weak gravity conjecture (WGC), based on which they concluded that all those non-supersymmetric AdS vacua that can be embedded within a constistent theory of quantum gravity necessarily develop instabilities. In this paper we further elaborate on this proposal by arguing that the aforementioned instabilities have a perturbative nature and arise from the crucial interplay between the closed and the open string sectors of the theory.
description: 14 pages, 5 figures
Disjoint linear dynamical properties of elementary operators
Creators: name: Ivkovic, Stefan
name: Tabatabaie, Seyyed Mohammad
Publisher: name: arXiv
Year: 2021
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: We characterize disjoint hypercyclic sequences of wedge operators. Also, we give some sufficient conditions for a sequence of the dual wedge operators to be disjoint topologically transitive. Finally, we give some concrete examples and applications.
description: This preprint has not undergone peer review (when applicable) or any post-submission improvements or corrections. The Version of Record of this article is published in Bulletin of the Iranian Mathematical Society, and is available online at https://doi.org/10.1007/s41980-023-00808-1
Data-driven analysis for understanding ultrahigh energy cosmic ray source spectra
Creators: name: Muzio, Marco Stein
name: Anchordoqui, Luis A.
name: Unger, Michael
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: One of the most challenging open questions regarding the origin of ultrahigh energy cosmic rays (UHECRs) deals with the shape of the source emission spectra. A commonly-used simplifying assumption is that the source spectra of the highest energy cosmic rays trace a Peters cycle, in which the maximum cosmic-ray energy scales linearly with $Z$, i.e., with the charge of the UHECR in units of the proton charge. However, this would only be a natural assumption for models in which UHECRs escape the acceleration region without suffering significant energy losses. In most cases, however, UHECRs interact in the acceleration region and/or in the source environment changing the shape of the source emission spectra. Energy losses are typically parameterized in terms of $Z$ and the UHECR baryon number $A$, and therefore one would expect the source emission spectra to be a function of both $Z$ and $A$. Taking a pragmatic approach, we investigate whether existing data favor any region of the $(Z,A)$ parameter space. Using data from the Pierre Auger Observatory, we carry out a maximum likelihood analysis of the observed spectrum and nuclear composition to shape the source emission spectra for the various particle species. We also study the impact of possible systematic uncertainties driven by hadronic models describing interactions in the atmosphere.
ANALISIS PENYELENGGARAAN PELAYANAN PUBLIK DALAM PENGAWASAN OMBUDSMAN DI INDONESIA
Creators: name: RIZKA ANANDA PUTRI
name: MIMIN SUNDARI NASUTION, S.Sos
Publisher: name: Zenodo
Year: 2023

description: Ombudsman merupakan sebuah lembaga yang memiliki kewenangan melakukan pengawasan terhadap penyelenggaraan pelayanan publik yang diselenggarakan oleh penyelenggara Negara dan pemerintahan termasuk yang diselenggarakan olen Badan Usaha Milik Negara dan Badan Usaha Milik Daerah yang diberi tugas menyelenggarakan pelayanan publik. Pengawasan yang dilakukan oleh Ombudsman terhadap penyelenggaraan pelayanan publik merupakan bentuk pengawasan eksternal yang bersifat represif. karena pengawasan tersebut dilakukan oleh lembaga diluar lembaga atau organ pemerintahan yang diawasi dan pada dasarnya pengawasan yang dilakukan oleh Ombudsman tersebut berbasis dari pengawasan masyarakat kemudian pengawasan lebih lanjut dilakukan oleh Ombudsman dan pengawasan tersebut dilakukan terhadap pengaduan oleh masyarakat terhadap tindakan maladministrasi yang dilakukan oleh pejabat publik.
Random access codes and non-local resources
Creators: name: Chaturvedi, Anubhav
name: Pawlowski, Marcin
name: Horodecki, Karol
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Information Theory (cs.IT)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: It is known that a PR-BOX (PR), a non-local resource and $(2\rightarrow 1)$ random access code (RAC), a functionality (wherein Alice encodes 2 bits into 1 bit message and Bob learns one of randomly chosen Alice's inputs) are equivalent under the no-signaling condition. In this work we introduce generalizations to PR and $(2\rightarrow 1)$ RAC and study their inter-convertibility. We introduce generalizations based on the number of inputs provided to Alice, $B_n$-BOX and $(n\rightarrow 1)$ RAC. We show that a $B_n$-BOX is equivalent to a no-signaling $(n\rightarrow 1)$ RACBOX (RB). Further we introduce a signaling $(n\rightarrow 1)$ RB which cannot simulate a $B_n$-BOX. Finally to quantify the same we provide a resource inequality between $(n\rightarrow 1)$ RB and $B_n$-BOX, and show that it is saturated. As an application we prove that one requires atleast $(n-1)$ PRs supplemented with a bit of communication to win a $(n\rightarrow 1)$ RAC. We further introduce generalizations based on the dimension of inputs provided to Alice and the message she sends, $B_n^d(+)$-BOX, $B_n^d(-)$-BOX and $(n\rightarrow 1,d)$ RAC ($d>2$). We show that no-signaling condition is not enough to enforce strict equivalence in the case of $d>2$. We introduce classes of no-signaling $(n\rightarrow 1,d)$ RB, one which can simulate $B_n^d(+)$-BOX, second which can simulate $B_n^d(-)$-BOX and third which cannot simulate either. Finally to quantify the same we provide a resource inequality between $(n\rightarrow 1,d)$ RB and $B_n^d(+)$-BOX, and show that it is saturated.
description: 17 pages, 6 figures
Ultrafast preparation and strong-field ionization of an atomic Bell-like state
Creators: name: Eckart, S.
name: Trabert, D.
name: Rist, J.
name: Geyer, A.
name: Schmidt, L. Ph. H.
name: Fehre, K.
name: Kunitski, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Molecules are many body systems with a substantial amount of entanglement between their electrons. Is there a way to break the molecular bond of a diatomic molecule and obtain two atoms in their ground state which are still entangled and form a Bell-like state? We present a scheme that allows for the preparation of such entangled atomic states from single oxygen molecules on femtosecond time scales. The two neutral oxygen atoms are entangled in the magnetic quantum number of their valence electrons. In a time-delayed probe step, we employ non-adiabatic tunnel ionization, which is a magnetic quantum number-sensitive mechanism. We then investigate correlations by comparing single and double ionization probabilities of the Bell-like state. The experimental results agree with the predictions for an entangled state.
description: 20 pages, 7 figures, 1 table
On approximate continuity and the support of reflected stochastic differential equations
Creators: name: Ren, Jiagang
name: Wu, Jing
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: In this paper we prove an approximate continuity result for stochastic differential equations with normal reflections in domains satisfying Saisho's conditions, which together with the Wong-Zakai approximation result completes the support theorem for such diffusions in the uniform convergence topology. Also by adapting Millet and Sanz-Solé's idea, we characterize in Hölder norm the support of diffusions reflected in domains satisfying the Lions-Sznitman conditions by proving limit theorems of adapted interpolations. Finally we apply the support theorem to establish a boundary-interior maximum principle for subharmonic functions.
description: Published at http://dx.doi.org/10.1214/15-AOP1018 in the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Effects of Defects and Dephasing on Charge and Spin Currents in Two-Dimensional Topological Insulators
Creators: name: Van Dyke, John S.
name: Morr, Dirk K.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Using the non-equilibrium Keldysh Green's function formalism, we investigate the effect of defects on the electronic structure and transport properties of two-dimensional topological insulators (TI). We demonstrate how the spatial flow of charge changes between the topologically protected edge and bulk states and show that elastically and inelastically scattering defects that preserve the time reversal symmetry of the TI lead to qualitatively different effects on the TI's local electronic structure and its transport properties. Moreover, we show that the recently predicted ability to create highly spin-polarized currents by breaking the time-reversal symmetry of the TI via magnetic defects [Phys. Rev. B 93, 081401 (2016)] is robust against the inclusion of a Rashba spin-orbit interaction and the effects of dephasing, and remains unaffected by changes over a wide range of the TI's parameters. We discuss how the sign of the induced spin currents changes under symmetry operations, such as reversal of bias and gate voltages, or spatial reflections. Finally, we show that the insight into the interplay between topology and symmetry of the magnetic defects can be employed for the creation of novel quantum phenomena, such as highly localized magnetic fields inside the TI.
Most Probable Transitions from Metastable to Oscillatory Regimes in a Carbon Cycle System
Creators: name: Wei, Wei
name: Hu, Jianyu
name: Chen, Jianyu
name: Duan, Jinqiao
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: Global climate changes are related to the ocean's store of carbon. We study a carbonate system of the upper ocean, which has metastable and oscillatory regimes, under small random fluctuations. We calculate the most probable transition path via a geometric minimum action method in the context of the large deviations theory. By examining the most probable transition paths from metastable to oscillatory regimes for various external carbon input rates, we find two different transition patterns, which gives us an early warning sign for the dramatic change in the carbonate state of the ocean.
description: 11 pages, 10 figures
Multimessenger Potential of the Radio Neutrino Observatory in Greenland
Creators: name: Muzio, Marco Stein
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The Radio Neutrino Observatory in Greenland (RNO-G) is the only ultrahigh energy (UHE, ${\gtrsim}30$~PeV) neutrino monitor of the Northern sky and will soon be the world's most sensitive high-uptime detector of UHE neutrinos. Because of this, RNO-G represents an important piece of the multimessenger landscape over the next decade. In this talk, we will highlight RNO-G's multimessenger capabilities and its potential to provide key information in the search for the most extreme astrophysical accelerators. In particular, we will highlight opportunities enabled by RNO-G's unique field-of-view, its potential to constrain the sources of UHE cosmic rays, and its complementarity with IceCube at lower energies.
Ethno-medicinal uses, ecology, phytochemistry, biological activities, and conservation approaches for Himalayan Rhubarb species
Creators: name: Kumar, Ashish
name: Jugran, Arun K.
name: Bargali, Surendra Singh
name: Bhatt, Indra D.
Publisher: name: Taylor & Francis
Year: 2025
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Evolutionary Biology
subject: Environmental Sciences not elsewhere classified
subject: Ecology

description: Rheum L. is an important genus of the family Polygonaceae comprised of nearly 60 herbaceous species distributed across the world. The members of Rheum genus are extensively used in curing several ailments, like wound healing, blood purification, menstruation problems, indigestion, headaches, chest pain, dysentery, stomachaches, fractured and broken bones, etc. The crude extracts and drugs derived from Rehum species possess anticancer, antimicrobial, anti-inflammatory, anti-SARS activity, and wound-healing properties. However, all the information on this genus is scattered and a systematic review of Rheum species is not available. The present study highlighted major distribution points, secondary metabolites, and pharmacological properties of Rheum species. A total of 144 unique compounds were recorded from Rheum genus, of them 24 were Stilbenes. This study further scientifically re-examines all published literature and explores market potential and pharmacology along with recommendations for the conservation of these high-value species.
Assistência de Enfermagem às mulheres privadas de liberdade: Revisão Integrativa
Creators: name: Conceição, Fabiana
name: Fraga, Viviani
Publisher: name: figshare
Year: 2022
Subjects: Nursing not elsewhere classified

description: O presente estudo tem como objetivo identificar as evidências disponíveis acerca da assistência de enfermagem às mulheres privadas de liberdade por meio de uma revisão integrativa. Elaborou-se a questão de pesquisa a partir da estratégia PICO, posteriormente será realizada a busca dos estudos a partir das bases de dados PubMed, Web of Science, LILACS, CINAHL e Scopus. Serão incluídos estudos primários que abordem a assistência de enfermagem às mulheres privadas de liberdade independentemente do tipo de delineamento, publicados em inglês, espanhol e português publicados entre os anos de 2012 e 2022. Em seguida será realizada a extração de dados dos estudos incluídos por meio de um roteiro construído pelos autores. Por conseguinte, será feita uma avaliação dos estudos afim de analisar o nível de evidência e a qualidade dos estudos incluídos. Os resultados contribuirão para uma assistência de qualidade às mulheres privadas de liberdade por meio do estímulo a possíveis novas ações a essa população, assim como identificar lacunas do conhecimento para o desenvolvimento de novas pesquisas na área, visto que é um cenário de pouca assistência à saúde dessas mulheres privadas de liberdade.
Subnetwork Constraints for Tighter Upper Bounds and Exact Solution of the Clique Partitioning Problem
Creators: name: Belyi, Alexander
name: Sobolevsky, Stanislav
name: Kurbatski, Alexander
name: Ratti, Carlo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Social and Information Networks (cs.SI)
subject: Discrete Mathematics (cs.DM)
subject: Optimization and Control (math.OC)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: G.2.2; I.5.3; I.2.8
subject: 05C85, 68T09, 68R10, 90C35, 90C90, 91C20

description: We consider a variant of the clustering problem for a complete weighted graph. The aim is to partition the nodes into clusters maximizing the sum of the edge weights within the clusters. This problem is known as the clique partitioning problem, being NP-hard in the general case of having edge weights of different signs. We propose a new method of estimating an upper bound of the objective function that we combine with the classical branch-and-bound technique to find the exact solution. We evaluate our approach on a broad range of random graphs and real-world networks. The proposed approach provided tighter upper bounds and achieved significant convergence speed improvements compared to known alternative methods.
description: 28 pages, 3 figures, 6 tables This version of the article has been accepted for publication after peer review but is not the Version of Record and does not reflect post-acceptance improvements or any corrections. The Version of Record is available online at Math Meth Oper Res (2023): https://doi.org/10.1007/s00186-023-00835-y
Spontaneous generation of a temperature anisotropy in a strongly coupled magnetized plasma
Creators: name: Ott, T.
name: Bonitz, M.
name: Hartmann, P.
name: Donkó, Z.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: A magnetic field was recently shown to enhance field-parallel heat conduction in a strongly correlated plasma whereas cross-field conduction is reduced. Here we show that in such plasmas, the magnetic field has the additional effect of inhibiting the isotropization process between field-parallel and cross-field temperature components thus leading to the emergence of strong and long-lived temperature anisotropies when the plasma is locally perturbed. An extended heat equation is shown to describe this process accurately.
Helicity reversion in high harmonic generation driven by bichromatic counterrotating circularly polarized laser fields
Creators: name: Zhang, Xiaofan
name: Li, Liang
name: Zhu, Xiaosong
name: Liu, Xi
name: Zhang, Qingbin
name: Lan, Pengfei
name: Lu, Peixiang
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We investigate the polarization properties of high harmonics generated with the bichromatic counterrotating circularly polarized (BCCP) laser fields by numerically solving time-dependent Schrödinger equation (TDSE). It is found that, the helicity of the elliptically polarized harmonic emission is reversed at particular harmonic orders. Based on the time-frequency analysis and the classical three-step model, the correspondence between the positions of helicity reversions and the classical trajectories of continuum electrons is established. It is shown that, the electrons ionized at one lobe of laser field can be divided into different groups based on the different lobes they recombine at, and the harmonics generated by adjacent groups have opposite helicities. Our study performs a detailed analysis of high harmonics in terms of electron trajectories and depicts a clear and intuitive physical picture of the HHG process in BCCP laser field.
Discrete Acoustic Space for an Efficient Sampling in Neural Text-To-Speech
Creators: name: Strong, Marek
name: Rohnke, Jonas
name: Bonafonte, Antonio
name: Łajszczak, Mateusz
name: Wood, Trevor
Publisher: name: arXiv
Year: 2021
Subjects: subject: Sound (cs.SD)
subject: Machine Learning (cs.LG)
subject: Audio and Speech Processing (eess.AS)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: We present a Split Vector Quantized Variational Autoencoder (SVQ-VAE) architecture using a split vector quantizer for NTTS, as an enhancement to the well-known Variational Autoencoder (VAE) and Vector Quantized Variational Autoencoder (VQ-VAE) architectures. Compared to these previous architectures, our proposed model retains the benefits of using an utterance-level bottleneck, while keeping significant representation power and a discretized latent space small enough for efficient prediction from text. We train the model on recordings in the expressive task-oriented dialogues domain and show that SVQ-VAE achieves a statistically significant improvement in naturalness over the VAE and VQ-VAE models. Furthermore, we demonstrate that the SVQ-VAE latent acoustic space is predictable from text, reducing the gap between the standard constant vector synthesis and vocoded recordings by 32%.
description: 5 pages, 5 figures, accepted at IberSPEECH 2022
DS-Depth: Dynamic and Static Depth Estimation via a Fusion Cost Volume
Creators: name: Miao, Xingyu
name: Bai, Yang
name: Duan, Haoran
name: Huang, Yawen
name: Wan, Fan
name: Xu, Xinxing
name: Long, Yang
name: Zheng, Yefeng
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Self-supervised monocular depth estimation methods typically rely on the reprojection error to capture geometric relationships between successive frames in static environments. However, this assumption does not hold in dynamic objects in scenarios, leading to errors during the view synthesis stage, such as feature mismatch and occlusion, which can significantly reduce the accuracy of the generated depth maps. To address this problem, we propose a novel dynamic cost volume that exploits residual optical flow to describe moving objects, improving incorrectly occluded regions in static cost volumes used in previous work. Nevertheless, the dynamic cost volume inevitably generates extra occlusions and noise, thus we alleviate this by designing a fusion module that makes static and dynamic cost volumes compensate for each other. In other words, occlusion from the static volume is refined by the dynamic volume, and incorrect information from the dynamic volume is eliminated by the static volume. Furthermore, we propose a pyramid distillation loss to reduce photometric error inaccuracy at low resolutions and an adaptive photometric error loss to alleviate the flow direction of the large gradient in the occlusion regions. We conducted extensive experiments on the KITTI and Cityscapes datasets, and the results demonstrate that our model outperforms previously published baselines for self-supervised monocular depth estimation.
Data-driven Control of Dynamic Event-triggered Systems with Delays
Creators: name: Wang, Xin
name: Sun, Jian
name: Berberich, Julian
name: Wang, Gang
name: Allgöwer, Frank
name: Chen, Jie
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper studies data-driven control of unknown sampled-data systems with communication delays under an event-triggering transmission mechanism. Data-based representations for time-invariant linear systems with known or unknown system input matrices are first developed, along with a novel class of dynamic triggering schemes for sampled-data systems with time delays. A model-based stability condition for the resulting event-triggered time-delay system is established using a looped-functional approach. Combining this model-based condition with the data-driven representations, data-based stability conditions are derived. Building on the data-based conditions, methods for co-designing the controller gain and the event-triggering matrix are subsequently provided for both cases with or without using the input matrix. Finally, numerical examples are presented to corroborate the usefulness of additional prior knowledge of the input matrix in reducing the conservatism of stability conditions, as well as the merits of the proposed data-driven event-triggered control schemes relative to existing results.
description: 15 pages,5 figures
Large deviation principle for Poisson driven SDEs in epidemic models
Creators: name: Pardoux, Etienne
name: Samegni-Kepgnou, Brice
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: We consider a general class of epidemic models obtained by applying a random time change to a collection of Poisson processes and we show the large deviation principle for such models. We generalize to a more general situation the approach followed by Dolgoaschinnykh [3] in the case of the SIR epidemic model. Thanks to an assumption which is satisfied in many examples, we simplify the recent work by P. Kratz and E. Pardoux [8].
The optical system of the Tenerife Microwave Spectrometer: a window for observing the 10-20 GHz sky spectra
Creators: name: Alonso-Arias, P.
name: Fuerte-Rodriguez, P. A.
name: Hoyland, R. J.
name: Rubino-Martin, J. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The TMS optical system is based on a decentered dual-reflector system in a Gregorian configuration to observe with an angular resolution of less than $2^\circ$. The primary goal of the present study is to evaluate the final design and verify that it satisfies the design requirements. We aim for low cross-polarization (-30 dB), low sidelobe (-25 dB) levels, and a stable beam in terms of shape (low ellipticity) and size over a full octave bandwidth (10-20 GHz). We performed both ray-tracing and full-wave simulations using the CST Studio software in order to investigate the system behaviour. We gave special attention to the beam frequency variation and polarization leakage. We have characterized the effects on the radiation pattern produced by the cryostat window. We present the final design of the TMS optical system, as well as a complete study of the system's performance in terms of cross-polarization, sidelobes, ellipticity and beamwidth. We discuss the effects of sidelobes and study the need for a baffle.
description: 30 pages, 15 figures. Accepted for publication in JINST
Insights from probability distribution functions of intensity maps
Creators: name: Breysse, Patrick C.
name: Kovetz, Ely D.
name: Behroozi, Peter S.
name: Dai, Liang
name: Kamionkowski, Marc
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In the next few years, intensity-mapping surveys that target lines such as CO, Ly$α$, and CII stand to provide powerful probes of high-redshift astrophysics. However, these line emissions are highly non-Gaussian, and so the typical power-spectrum methods used to study these maps will leave out a significant amount of information. We propose a new statistic, the probability distribution of voxel intensities, which can access this extra information. Using a model of a CO intensity map at $z\sim3$ as an example, we demonstrate that this voxel intensity distribution (VID) provides substantial constraining power beyond what is obtainable from the power spectrum alone. We find that a future survey similar to the planned COMAP Full experiment could constrain the CO luminosity function to order $\sim10\%$. We also explore the effects of contamination from continuum emission, interloper lines, and gravitational lensing on our constraints and find that the VID statistic retains significant constraining power even in pessimistic scenarios.
description: 14 pages, 13 figures, submitted to MNRAS
Double-Frame Current Control with a Multivariable PI Controller and Power Compensation forWeak Unbalanced Networks
Creators: name: Siemaszko, Daniel
name: Rufery, Alfred
Publisher: name: arXiv
Year: 2016
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: The handling of weak networks with asymmetric loads and disturbances implies the accurate handling of the second-harmonic component that appears in an unbalanced network. This paper proposes a classic vector control approach using a PI-based controller with superior decoupling capabilities for operation in weak networks with unbalanced phase voltages. A synchronization method for weak unbalanced networks is detailed, with dedicated dimensioning rules. The use of a double-frame controller allows a current symmetry or controlled imbalance to be forced for compensation of power oscillations by controlling the negative current sequence. This paper also serves as a useful reminder of the proper way to cancel the inherent coupling effect due to the transformation to the synchronous rotating reference frame, and of basic considerations of the relationship between switching frequency and control bandwidth.
description: 17 pages, contribution to the 2014 CAS - CERN Accelerator School: Power Converters, Baden, Switzerland, 7-14 May 2014
Intertwining of lasing and superradiance under spintronic pumping
Creators: name: Chelpanova, Oksana
name: Lerose, Alessio
name: Zhang, Shu
name: Carusotto, Iacopo
name: Tserkovnyak, Yaroslav
name: Marino, Jamir
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We introduce a quantum optics platform featuring the minimal ingredients for the description of a spintronically pumped magnon condensate, which we use to promote driven-dissipative phase transitions in the context of spintronics. We consider a Dicke model weakly coupled to an out-of-equilibrium bath with a tunable spin accumulation. The latter is pumped incoherently in a fashion reminiscent of experiments with magnet-metal heterostructures. The core of our analysis is the emergence of a hybrid lasing-superradiant regime that does not take place in an ordinary pumped Dicke spin ensemble, and which can be traced back to the spintronics pumping scheme. We interpret the resultant non-equilibrium phase diagram from both a quantum optics and a spintronics standpoint, supplying a conceptual bridge between the two fields. The outreach of our results concern dynamical control in magnon condensates and frequency-dependent gain media in quantum optics.
description: 13 pages, 10 figures
Fuzzy-based Propagation of Prior Knowledge to Improve Large-Scale Image Analysis Pipelines
Creators: name: Stegmaier, Johannes
name: Mikut, Ralf
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Computer and information sciences
subject: FOS: Biological sciences

description: Many automatically analyzable scientific questions are well-posed and offer a variety of information about the expected outcome a priori. Although often being neglected, this prior knowledge can be systematically exploited to make automated analysis operations sensitive to a desired phenomenon or to evaluate extracted content with respect to this prior knowledge. For instance, the performance of processing operators can be greatly enhanced by a more focused detection strategy and the direct information about the ambiguity inherent in the extracted data. We present a new concept for the estimation and propagation of uncertainty involved in image analysis operators. This allows using simple processing operators that are suitable for analyzing large-scale 3D+t microscopy images without compromising the result quality. On the foundation of fuzzy set theory, we transform available prior knowledge into a mathematical representation and extensively use it enhance the result quality of various processing operators. All presented concepts are illustrated on a typical bioimage analysis pipeline comprised of seed point detection, segmentation, multiview fusion and tracking. Furthermore, the functionality of the proposed approach is validated on a comprehensive simulated 3D+t benchmark data set that mimics embryonic development and on large-scale light-sheet microscopy data of a zebrafish embryo. The general concept introduced in this contribution represents a new approach to efficiently exploit prior knowledge to improve the result quality of image analysis pipelines. Especially, the automated analysis of terabyte-scale microscopy data will benefit from sophisticated and efficient algorithms that enable a quantitative and fast readout. The generality of the concept, however, makes it also applicable to practically any other field with processing strategies that are arranged as linear pipelines.
description: 39 pages, 12 figures
Localization and fractality in disordered Russian Doll model
Creators: name: Motamarri, Vedant
name: Gorsky, Alexander S.
name: Khaymovich, Ivan M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Superconductivity (cond-mat.supr-con)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Motivated by the interplay of Bethe-Ansatz integrability and localization in the Richardson model of superconductivity, we consider a time-reversal symmetry breaking deformation of this model, known as the Russian Doll Model (RDM), and implement diagonal on-site disorder. The localization and ergodicity-breaking properties of the single-particle spectrum are analyzed using a large-energy renormalization group (RG) over the momentum-space spectrum. Based on the above RG, we derive an effective Hamiltonian of the model, discover a fractal phase of non-ergodic delocalized states -- with the fractal dimension different from the paradigmatic Rosenzweig-Porter model -- and explain it in terms of the developed RG equations and the matrix-inversion trick.
description: 18 pages, 6 figures, 49 references + 5 pages, 2 figures in Appendices
$(1+3)$D topological superconductors: screening and confinement in presence of external fields
Creators: name: Gaete, Patricio
name: Helayël-Neto, José A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Adopting the gauge-invariant and path-dependent variables formalism, we compute the interaction energy for a topological field theory describing $(1+3)$D topological superconductors in presence of external fields. As a result, in the case of a constant electric field- strength expectation value, we show that the interaction energy describes a purely screening phase, encoded in a Yukawa potential. On the other hand, in the case of a constant magnetic field-strength and for a very small Josephson coupling constant, the particle-antiparticle binding potential displays a linear term leading to the confinement of static charge probes along with a screening contribution.
description: 6 pages
Speeding up Learning Quantum States through Group Equivariant Convolutional Quantum Ansätze
Creators: name: Zheng, Han
name: Li, Zimu
name: Liu, Junyu
name: Strelchuk, Sergii
name: Kondor, Risi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: Mathematical Physics (math-ph)
subject: Machine Learning (stat.ML)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We develop a theoretical framework for $S_n$-equivariant convolutional quantum circuits with SU$(d)$-symmetry, building on and significantly generalizing Jordan's Permutational Quantum Computing (PQC) formalism based on Schur-Weyl duality connecting both SU$(d)$ and $S_n$ actions on qudits. In particular, we utilize the Okounkov-Vershik approach to prove Harrow's statement (Ph.D. Thesis 2005 p.160) on the equivalence between $\operatorname{SU}(d)$ and $S_n$ irrep bases and to establish the $S_n$-equivariant Convolutional Quantum Alternating Ansätze ($S_n$-CQA) using Young-Jucys-Murphy (YJM) elements. We prove that $S_n$-CQA is able to generate any unitary in any given $S_n$ irrep sector, which may serve as a universal model for a wide array of quantum machine learning problems with the presence of SU($d$) symmetry. Our method provides another way to prove the universality of Quantum Approximate Optimization Algorithm (QAOA) and verifies that 4-local SU($d$) symmetric unitaries are sufficient to build generic SU($d$) symmetric quantum circuits up to relative phase factors. We present numerical simulations to showcase the effectiveness of the ansätze to find the ground state energy of the $J_1$--$J_2$ antiferromagnetic Heisenberg model on the rectangular and Kagome lattices. Our work provides the first application of the celebrated Okounkov-Vershik's $S_n$ representation theory to quantum physics and machine learning, from which to propose quantum variational ansätze that strongly suggests to be classically intractable tailored towards a specific optimization problem.
description: 15 pages, 11 figures
Relative perfect complexes
Creators: name: Alonso, Leovigildo
name: Jeremias, Ana
name: Sancho, Fernando
Publisher: name: arXiv
Year: 2021
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14F08 (primary), 14F99 (secondary)

description: Let $f \colon X \to Y$ be a morphism of concentrated schemes. We characterize $f$-perfect complexes $\mathcal{E}$ as those such that the functor $\mathcal{E} \otimes^{\mathbf{L}}_X \mathbf{L} f^*-$ preserves bounded complexes. We prove, as a consequence, that a quasi-proper morphism takes relative perfect complexes into perfect ones. We obtain a generalized version of the semicontinuity theorem of dimension of cohomology and Grauert's base change of the fibers. Finally, a bivariant theory of the Grothendieck group of perfect complexes is developed.
description: Final version. 27 pages
Absence of nematic ordering transition in a diamond lattice: Application to $FeSc_2S_4$
Creators: name: Setty, Chandan
name: Leong, Zhidong
name: Zhang, Shuyi
name: Phillips, Philip W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Recent neutron scattering observations by Plumb et al. [1] reveal that the ground state of $FeSc_2S_4$ is magnetic with two distinct Fe environments, instead of a quantum spin liquid as had been previously thought. Starting with the relevant O(N)-symmetric vector model of $FeSc_2S_4$, we study how the discrete ($Z_2$) and continuous rotational symmetries are successively broken, yielding nematic and ordered phases. At high temperatures, we find that the nematic order parameter falls as $T^{-γ}$ ($γ>0$), and therefore, $FeSc_2S_4$ lacks any distinct nematic ordering temperature. This feature indicates that the three-dimensional diamond lattice of $FeSc_2S_4$ is highly susceptible to the breaking of Ising symmetries, and explains the two distinct Fe environments that is present even at high temperatures, as seen by Mössbauer and far infrared optical spectroscopy.
description: 9 pages with Supplemental Material, 5 figures
Non-ergodic delocalized phase with Poisson level statistics
Creators: name: Tang, Weichen
name: Khaymovich, Ivan M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Motivated by the many-body localization (MBL) phase in generic interacting disordered quantum systems, we develop a model simulating the same eigenstate structure like in MBL, but in the random-matrix setting. Demonstrating the absence of energy level repulsion (Poisson statistics), this model carries non-ergodic eigenstates, delocalized over the extensive number of configurations in the Hilbert space. On the above example, we formulate general conditions to a single-particle and random-matrix models in order to carry such states, based on the transparent generalization of the Anderson localization of single-particle states and multiple resonances.
description: 24 pages, 6 figures, 73 references + 3 pages in Appendix, accepted to Quantum journal
Observation of Dirac surface states in the noncentrosymmetric superconductor BiPd
Creators: name: Benia, H. M.
name: Rampi, E.
name: Trainer, C.
name: Yim, C. M.
name: Maldonado, A.
name: Peets, D. C.
name: Stoehr, A.
name: Starke, U.
name: Kern, K.
name: Yaresko, A.
name: Levy, G.
name: Damascelli, A.
name: Ast, C. R.
name: Schnyder, A. P.
name: Wahl, P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Materials with strong spin-orbit coupling (SOC) have in recent years become a subject of intense research due to their potential applications in spintronics and quantum information technology. In particular, in systems which break inversion symmetry, SOC facilitates the Rashba-Dresselhaus effect, leading to a lifting of spin degeneracy in the bulk and intricate spin textures of the Bloch wave functions. Here, by combining angular resolved photoemission (ARPES) and low temperature scanning tunneling microscopy (STM) measurements with relativistic first-principles band structure calculations, we examine the role of SOC in single crystals of noncentrosymmetric BiPd. We report the detection of several Dirac surface states, one of which exhibits an extremely large spin splitting. Unlike the surface states in inversion-symmetric systems, the Dirac surface states of BiPd have completely different properties at opposite faces of the crystal and are not trivially linked by symmetry. The spin-splitting of the surface states exhibits a strong anisotropy by itself, which can be linked to the low in-plane symmetry of the surface termination.
description: 6 page letter, + supplementary material
Sub-diffusive Thouless time scaling in the Anderson model on random regular graphs
Creators: name: Colmenarez, Luis
name: Luitz, David J.
name: Khaymovich, Ivan M.
name: De Tomasi, Giuseppe
Publisher: name: arXiv
Year: 2022
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The scaling of the Thouless time with system size is of fundamental importance to characterize dynamical properties in quantum systems. In this work, we study the scaling of the Thouless time in the Anderson model on random regular graphs with on-site disorder. We determine the Thouless time from two main quantities: the spectral form factor and the power spectrum. Both quantities probe the long-range spectral correlations in the system and allow us to determine the Thouless time as the time scale after which the system is well described by random matrix theory. We find that the scaling of the Thouless time is consistent with the existence of a sub-diffusive regime anticipating the localized phase. Furthermore, to reduce finite-size effects, we break energy conservation by introducing a Floquet version of the model and show that it hosts a similar sub-diffusive regime.
description: 9 pages, 7 figures, 118 references + 1 page, 3 figures in Appendices
Towards Robust Adaptive Radiation Therapy Strategies
Creators: name: Böck, Michelle
name: Forsgren, Anders
name: Eriksson, Kjell
name: Hårdemark, Björn
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: The authors propose robust adaptive strategies based on stochastic minimax optimization for a series of simulated treatments on a one-dimensional patient phantom. The plan applied during the first fractions should be able to handle anticipated systematic and random errors. At scheduled fractions, the impact of the measured errors on the delivered dose distribution is evaluated. For a patient receiving a dose that does not satisfy clinical goals, the plan is reoptimized based on these individually measured errors. The adapted plan is then applied during subsequent fractions until a new scheduled adaptation becomes necessary. In the first adaptive strategy, the measured systematic and random error scenarios and their assigned probabilities are updated to guide the robust reoptimization. In the second strategy, the grade of conservativeness is adapted in response to the measured dose delivery errors. In the third strategy, the uncertainty margins around the target are recalculated based on the measured errors. The simulated systematic and random errors are either similar to the anticipated errors or unpredictably larger, in order to critically evaluate the performance of the adaptive strategies. The simulations show that robustly optimized treatment plans provide sufficient treatment quality for those treatment error scenarios similar to the anticipated error scenarios. Combining robust planning with adaptation leads to improved OAR protection. In case of unpredictably larger treatment errors, the first strategy performs best at improving treatment quality in terms of target coverage and OAR protection. According to the simulations, these robust adaptive treatment strategies are able to identify candidates for an adaptive treatment, thus giving the opportunity to provide individualized plans, and improve their treatment quality through adaptation.