cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Can the Low Redshift Lyman Alpha Forest Constrain AGN Feedback Models?
Creators: name: Khaire, Vikram
name: Hu, Teng
name: Hennawi, Joseph F.
name: Walther, Michael
name: Davies, Frederick
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We investigate the potential of low-redshift Lyman alpha (Ly$α$) forest for constraining active galactic nuclei (AGN) feedback models by analyzing the Illustris and IllustrisTNG simulation at z=0.1. These simulations are ideal for studying the impact of AGN feedback on the intergalactic medium (IGM) as they share initial conditions with significant differences in the feedback prescriptions. Both simulations reveal that the IGM is significantly impacted by AGN feedback. Specifically, feedback is stronger in Illustris and results in reducing cool baryon fraction to 23% relative to 39% in IllustrisTNG. However, when comparing various statistics of Ly$α$ forest such as 2D and marginalized distributions of Doppler widths and H I column density, line density, and flux power spectrum with real data, we find that most of these statistics are largely insensitive to the differences in feedback models. This lack of sensitivity arises because of the fundamental degeneracy between the fraction of cool baryons and the H I photoionization rate ($Γ_{\rm HI}$) as their product determines the optical depth of the Ly$α$ forest. Since the $Γ_{\rm HI}$ cannot be precisely predicted from first principles, it needs to be treated as a nuisance parameter adjusted to match the observed Ly$α$ line density. After adjusting $Γ_{\rm HI}$, the distinctions in the considered statistics essentially fade away. Only the Ly$α$ flux power spectrum at small spatial scales exhibits potentially observable differences, although this may be specific to the relatively extreme feedback model employed in Illustris. Without independent constraints on either $Γ_{\rm HI}$ or cool baryon fraction, constraining AGN feedback with low-redshift Ly$α$ forest will be very challenging.
description: 20 Pages, 11 Figures, Accepted for publication in MNRAS
Criticality in transport through the quantum Ising chain
Creators: name: Vogl, Malte
name: Schaller, Gernot
name: Brandes, Tobias
Publisher: name: arXiv
Year: 2012
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider thermal transport between two reservoirs coupled by a quantum Ising chain as a model for non-equilibrium physics induced in quantum-critical many-body systems. By deriving rate equations based on exact expressions for the quasiparticle pairs generated during the transport, we observe signatures of the underlying quantum phase transition in the steady-state energy current already at finite reservoir temperatures.
description: to appear in PRL
Additional file 3 of A novel protein encoded by circFNDC3B inhibits tumor progression and EMT through regulating Snail in colon cancer
Creators: name: Pan, Zihao
name: Cai, Jianye
name: Lin, Jiatong
name: Zhou, Huinian
name: Peng, Jingwen
name: Liang, Jinliang
name: Xia, Long
name: Yin, Qi
name: Zou, Baojia
name: Zheng, Jun
name: Qiao, Liang
name: Zhang, Lei
Publisher: name: figshare
Year: 2020
Subjects: subject: Biochemistry
subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Pharmacology
subject: Chemical Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Cancer
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: Additional file 3: Table S2. Antibodies used in this study
OpenSQUID: a flexible open-source software framework for the control of SQUID electronics
Creators: name: Jaeckel, Felix T.
name: Lafler, Randy J.
name: Boyd, S. T. P.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Commercially available computer-controlled SQUID electronics are usually delivered with software providing a basic user interface for adjustment of SQUID tuning parameters, such as bias current, flux offset, and feedback loop settings. However, in a research context it would often be useful to be able to modify this code and/or to have full control over all these parameters from researcher-written software. In the case of the STAR Cryoelectronics PCI/PFL family of SQUID control electronics, the supplied software contains modules for automatic tuning and noise characterization, but does not provide an interface for user code. On the other hand, the Magnicon SQUIDViewer software package includes a public application programming interface (API), but lacks auto-tuning and noise characterization features. To overcome these and other limitations, we are developing an "open-source" framework for controlling SQUID electronics which should provide maximal interoperability with user software, a unified user interface for electronics from different manufacturers, and a flexible platform for the rapid development of customized SQUID auto-tuning and other advanced features. We have completed a first implementation for the STAR Cryoelectronics hardware and have made the source code for this ongoing project available to the research community on SourceForge (http://opensquid.sourceforge.net) under the GNU public license.
description: Applied Superconductivity Conference 2012
Entanglement of two superconducting qubits in a waveguide cavity via monochromatic two-photon excitation
Creators: name: Poletto, S.
name: Gambetta, Jay M.
name: Merkel, Seth T.
name: Smolin, John A.
name: Chow, Jerry M.
name: Corcoles, A. D.
name: Keefe, George A.
name: Rothwell, Mary B.
name: Rozen, J. R.
name: Abraham, D. W.
name: Rigetti, Chad
name: Steffen, M.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantum Physics (quant-ph)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We report a system where fixed interactions between non-computational levels make bright the otherwise forbidden two-photon 00 --> 11 transition. The system is formed by hand selection and assembly of two discrete component transmon-style superconducting qubits inside a rectangular microwave cavity. The application of a monochromatic drive tuned to this transition induces two-photon Rabi-like oscillations between the ground and doubly-excited states via the Bell basis. The system therefore allows all-microwave two-qubit universal control with the same techniques and hardware required for single qubit control. We report Ramsey-like and spin echo sequences with the generated Bell states, and measure a two-qubit gate fidelity of 90% (unconstrained) and 86% (maximum likelihood estimator).
description: 5 pages, 4 figures. V2: add supplemental material about the Schrieffer-Wolff transformation
Observation of the 717 nm electric quadrupole transition in triply charged thorium
Creators: name: Radnaev, A. G.
name: Campbell, C. J.
name: Kuzmich, A.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We excite the 717 nm electric quadrupole 6$D_{3/2} $ $\leftrightarrow$ 7$S_{1/2}$ transition in a laser-cooled $^{232}$Th$^{3+}$ ion crystal. The transition frequency and the lifetime of the metastable 7$S_{1/2}$ level are measured to be 417 845 964(30) MHz and 0.60(7) s, respectively. We subsequently employ the 7$S_{1/2}$ level to drive the ions with nanosecond-long 269 nm laser pulses into the 7$P_{1/2}$ level. The latter is connected to the 7$S_{1/2}$ electronic level within the $^{229}$Th nuclear isomer manifold by the strongest available electron-bridge transition, forming a basis for its laser excitation.
description: 5 pages, 5 figures
Manufacturing and Industrialization in Malawi: Trends, Opportunities, and Strategies
Creators: name: Mkwambisi, David
name: Muyanga, Milu
name: Amedie, Wassihun
name: Makocho, Paul
name: Lifeyo, Yanjanani
name: Khomba, James K.
Publisher: name: Unknown
Year: 2020
Subjects: subject: Agricultural and Food Policy
subject: International Development
subject: Malawi
subject: Structural Transformation
subject: Industrialization
subject: Manufacturing
subject: Policy

description: Key Messages: •Invest in increased agricultural productivity to raise incomes and increase domestic demand for manufactured products. •Develop a coordinated industrialization policy that covers key sectors of the economy including agriculture, mining, energy, labor, finance, and trade. •Invest in physical infrastructure (feeder roads, railways, electricity, and information and communication technology) to reduce the cost of doing business. •Cluster strategic industries (industries with high comparative advantage, potential for forward and backward linkages, and high content of domestic raw materials) into special economic zones for effective infrastructure and other services targeting. •Establish a well-funded industrial and agricultural research and development (R&D) system. •Maintain stable macroeconomic environment for increased private sector investments, reduced cost of borrowing, and to boost foreign direct investment inflows. •Invest in human resource development for improved technical skillsets necessary for more specialized forms of production. •Develop a forward-thinking strategy to tap into the expanded regional markets and engage regional value chains in subsectors where Malawi has comparative advantage. •Develop and implement a comprehensive anti-corruption strategy that should include a demonstration of credible intent to fight corruption, increased anti-corruption campaigns, and strict enforcement of laws.
Formation of trapped vacuum bubbles during inflation, and consequences for PBH scenarios
Creators: name: Escrivà, Albert
name: Atal, Vicente
name: Garriga, Jaume
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A class of inflationary scenarios for primordial black hole (PBH) formation include a small barrier in the slope of the potential. There, the inflaton slows down, generating an enhancement of primordial perturbations. Moreover, the background solution overcomes the barrier at a very low speed, and large backward quantum fluctuations can prevent certain regions from overshooting the barrier. This leads to localized bubbles where the field remains trapped behind the barrier. In such models, therefore, we have two distinct channels for PBH production: the standard adiabatic density perturbation channel and the bubble channel. Here, we perform numerical simulations of bubble formation, addressing the issues of initial conditions, critical amplitude and bubble expansion. Further, we explore the scaling behaviour of the co-moving size of bubbles with the initial amplitude of the field fluctuation. We find that for small to moderate non-Gaussianity $f_{\rm NL}\lesssim 2.6$, the threshold for the formation of vacuum bubbles agrees with previous analytical estimates arXiv:1908.11357 to $5\%$ accuracy or so. We also show that the mass distribution for the two channels is different, leading to a slightly broader range of PBH masses. The bubble channel is subdominant for small $f_{\rm NL}$, and becomes dominant for $f_{\rm NL}\gtrsim 2.6$. We find that the mass of PBHs in the bubble channel is determined by an adiabatic overdensity surrounding the bubble at the end of inflation. Remarkably, the profile of this overdensity turns out to be of type-II. This represents a first clear example showing that overdensities of type-II can be dominant relative to the standard type-I. We also comment on exponential tails and on the fact that in models with local type non-Gaussianity (such as the one considered here), the occurrence of alternative channels can easily be inferred from unitarity considerations.
description: 41 pages and 18 figures. v3: minor comments and references added. Accepted for publication in JCAP
Les revues savantes québécoises : un état des lieux
Creators: name: van Bellen, Simon
name: Marcoux, Richard
name: Paquin, Émilie
Publisher: name: Zenodo
Year: 2022
Subjects: Revues nationales, Québec, publication savante, sciences humaines, sciences sociales

description: Présentation au Congrès de l'Acfas, mai 2022.
Advances in ab-initio theory of Multiferroics. Materials and mechanisms: modelling and understanding
Creators: name: Picozzi, Silvia
name: Stroppa, Alessandro
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Within the broad class of multiferroics (compounds showing a coexistence of magnetism and ferroelectricity), we focus on the subclass of "improper electronic ferroelectrics", i.e. correlated materials where electronic degrees of freedom (such as spin, charge or orbital) drive ferroelectricity. In particular, in spin-induced ferroelectrics, there is not only a {\em coexistence} of the two intriguing magnetic and dipolar orders; rather, there is such an intimate link that one drives the other, suggesting a giant magnetoelectric coupling. Via first-principles approaches based on density functional theory, we review the microscopic mechanisms at the basis of multiferroicity in several compounds, ranging from transition metal oxides to organic multiferroics (MFs) to organic-inorganic hybrids (i.e. metal-organic frameworks, MOFs)
description: 22 pages, 9 figures
Die Skelette des Leubinger Grabhügels
Creators: name: Müller, Wilhelm
Publisher: name: Jahresschrift für mitteldeutsche Vorgeschichte
Year: 2019

description: -
description: Jahresschrift für mitteldeutsche Vorgeschichte, Bd. 5 (1906): Jahresschrift für die Vorgeschichte der sächsisch-thüringischen Länder
Deliverable 2.6 BlockStart DLT Assessment Tool - 3rd Version
Creators: name: UAB CIVITTA
Publisher: name: Zenodo
Year: 2021
Subjects: blockchain
startups
end-users
fintech
ict
retail
dlt
assessment

description: BlockStart project has created and published a DLT Assessment Tool, which aims to evaluate SMEs/ startups capacity and potential to start using the technology. The first version of the DLT Assessment Tool was made available in BlockStart’s website (www.blockstart.eu/dlt/) in M4 of the project (December 2019) and has been updated according to the insights from internal and external discussions with the consortium partners and experts that participated in the programme. This deliverable overviews the main insights from the previous version of the tool, the changes made to the updated version as well as the traction and responses collected from the introduction of the updated tool in M10 until this point (M20, roughly 10 months). Since the last iteration in M10, no significant changes have been made to the content and questions of the tool. This allows us to collect a larger amount of significant responses and statistical data, outlined in detail below. The DLT Assessment Tool has been published using Typeform’s platform, due to its convenient functionality and user-friendliness. The platform allows building custom logic on the questions flow based on the answers. It also provides useful statistics on the drop-off rate and allows the questionnaire to be embedded into the BlockStart’s website.
Leveraging User-Wise SVD for Accelerated Convergence in Iterative ELAA-MIMO Detections
Creators: name: Liu, Jiuyu
name: Ma, Yi
name: Tafazolli, Rahim
Publisher: name: arXiv
Year: 2023
Subjects: subject: Information Theory (cs.IT)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Numerous low-complexity iterative algorithms have been proposed to offer the performance of linear multiple-input multiple-output (MIMO) detectors bypassing the channel matrix inverse. These algorithms exhibit fast convergence in well-conditioned MIMO channels. However, in the emerging MIMO paradigm utilizing extremely large aperture arrays (ELAA), the wireless channel may become ill-conditioned because of spatial non-stationarity, which results in a considerably slower convergence rate for these algorithms. In this paper, we propose a novel ELAA-MIMO detection scheme that leverages user-wise singular value decomposition (UW-SVD) to accelerate the convergence of these iterative algorithms. By applying UW-SVD, the MIMO signal model can be converted into an equivalent form featuring a better-conditioned transfer function. Then, existing iterative algorithms can be utilized to recover the transmitted signal from the converted signal model with accelerated convergence towards zero-forcing performance. Our simulation results indicate that proposed UW-SVD scheme can significantly accelerate the convergence of the iterative algorithms in spatially non-stationary ELAA channels. Moreover, the computational complexity of the UW-SVD is comparatively minor in relation to the inherent complexity of the iterative algorithms.
description: Legend correction to Fig. 2(b)
Multi-Year Time-Series-Based power system planning with hybrid optimization and supervised learning methods
Creators: name: Schäfer, Florian
Publisher: name: Universität Kassel
Year: 2021
Subjects: subject: power system planning
subject: machine learning
subject: hybrid optimization
subject: high voltage systems
subject: supervised learning
subject: 620
subject: Elektrizitätsmanagement
subject: Intelligentes Stromnetz
subject: Energiemanagement
subject: Energieerzeugung
subject: Energieeffizienz

description: Zugleich: Dissertation, Universität Kassel, 2020
Optimized detector tomography for photon-number resolving detectors with hundreds of pixels
Creators: name: Liu, Dong-Sheng
name: Wang, Jia-Qi
name: Zou, Chang-Ling
name: Ren, Xi-Feng
name: Guo, Guang-Can
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Photon-number resolving detectors with hundreds of pixels are now readily available, while the characterization of these detectors using detector tomography is computationally intensive. Here, we present a modified detector tomography model that reduces the number of variables that need optimization. To evaluate the effectiveness and accuracy of our model, we reconstruct the photon number distribution of optical coherent and thermal states using the expectation-maximization-entropy algorithm. Our results indicate that the fidelity of the reconstructed states remains above 99%, and the second and third-order correlations agree well with the theoretical values for a mean number of photons up to 100. We also investigate the computational resources required for detector tomography and find out that our approach reduces the solving time by around a half compared to the standard detector tomography approach, and the required memory resources are the main obstacle for detector tomography of a large number of pixels. Our results suggest that detector tomography is viable on a supercomputer with 1~TB RAM for detectors with up to 340 pixels.
The Optical Colors of Giant Elliptical Galaxies and their Metal-Rich Globular Clusters Indicate a Bottom-Heavy Initial Mass Function
Creators: name: Goudfrooij, Paul
name: Kruijssen, J. M. Diederik
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We report a systematic and statistically significant offset between the optical (g-z or B-I) colors of seven massive elliptical galaxies and the mean colors of their associated massive metal-rich globular clusters (GCs) in the sense that the parent galaxies are redder by 0.12-0.20 mag at a given galactocentric distance. However, spectroscopic indices in the blue indicate that the luminosity-weighted ages and metallicities of such galaxies are equal to that of their averaged massive metal-rich GCs at a given galactocentric distance, to within small uncertainties. The observed color differences between the red GC systems and their parent galaxies cannot be explained by the presence of multiple stellar generations in massive metal-rich GCs, as the impact of the latter to the populations' integrated g-z or B-I colors is found to be negligible. However, we show that this paradox can be explained if the stellar initial mass function (IMF) in these massive elliptical galaxies was significantly steeper at subsolar masses than canonical IMFs derived from star counts in the solar neighborhood, with the GC colors having become bluer due to dynamical evolution, causing a significant flattening of the stellar MF of the average surviving GC.
description: 12 pages (in emulateapj format), incl. 12 figures and 3 tables; published in The Astrophysical Journal
Optimal Sensor Placement for Target Localization and Tracking in 2D and 3D
Creators: name: Zhao, Shiyu
name: Chen, Ben M.
name: Lee, Tong H.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper analytically characterizes optimal sensor placements for target localization and tracking in 2D and 3D. Three types of sensors are considered: bearing-only, range-only, and received-signal-strength. The optimal placement problems of the three sensor types are formulated as an identical parameter optimization problem and consequently analyzed in a unified framework. Recently developed frame theory is applied to the optimality analysis. We prove necessary and sufficient conditions for optimal placements in 2D and 3D. A number of important analytical properties of optimal placements are further explored. In order to verify the analytical analysis, we present a gradient control law that can numerically construct generic optimal placements.
Moments of L'(1/2) in the Family of Quadratic Twists
Creators: name: Petrow, Ian
Publisher: name: arXiv
Year: 2012
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: We prove the asymptotic formulae for several moments of derivatives of GL(2) L-functions over quadratic twists. The family of L-functions we consider has root number fixed to -1 and odd orthogonal symmetry. Assuming GRH we prove the asymptotic formulae for (1) the second moment with one secondary term, (2) the moment of two distinct modular forms f and g and (3) the first moment with controlled weight and level dependence. We also include some immediate corollaries to elliptic curves via the modularity theorem and the work of Gross and Zagier.
description: Many minor typos fixed and improvements in the writing made in this revision. To appear in IMRN
Non-anticommutativity in Presence of a Boundary
Creators: name: Faizal, Mir
name: Smith, Douglas J.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper we consider non-anticommutative field theories in $\mathcal{N} =2$ superspace formalism on three-dimensional manifolds with a boundary. We modify the original Lagrangian in such a way that it preserves half the supersymmetry even in the presence of a boundary. We also analyse the partial breaking of supersymmetry caused by non-anticommutativity between fermionic coordinates. Unlike in four dimensions, in three dimensions a theory with $\mathcal{N} =1/2$ supersymmetry cannot be obtained by a non-anticommutative deformation of an $\mathcal{N} =1$ theory. However, in this paper we construct a three dimensional theory with $\mathcal{N} =1/2$ supersymmetry by studying a combination of non-anticommutativity and boundary effects, starting from $\mathcal{N} =2$ supersymmetry.
description: 13 pages, 0 figures, accepted for publication in Phys. Rev. D
Numerical convergence of model Cauchy-characteristic extraction and matching
Creators: name: Giannakopoulos, Thanasis
name: Bishop, Nigel T.
name: Hilditch, David
name: Pollney, Denis
name: Zilhão, Miguel
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Gravitational waves provide a powerful enhancement to our understanding of fundamental physics. To make the most of their detection we need to accurately model the entire process of their emission and propagation toward interferometers. Cauchy-characteristic extraction and matching are methods to compute gravitational waves at null infinity, a mathematical idealization of detector location, from numerical relativity simulations. Both methods can in principle contribute to modeling by providing highly accurate gravitational waveforms. An underappreciated subtlety in realizing this potential is posed by the (mere) weak hyperbolicity of the particular PDE systems solved in the characteristic formulation of the Einstein field equations. This shortcoming results from the popular choice of Bondi-like coordinates. So motivated, we construct toy models that capture that PDE structure and study Cauchy-characteristic extraction and matching with them. Where possible we provide energy estimates for their solutions and perform careful numerical norm convergence tests to demonstrate the effect of weak hyperbolicity on Cauchy-characteristic extraction and matching. Our findings strongly indicate that, as currently formulated, Cauchy-characteristic matching for the Einstein field equations would provide solutions that are, at best, convergent at an order lower than expected for the numerical method, and may be unstable. In contrast, under certain conditions, the extraction method can provide properly convergent solutions. Establishing however that these conditions hold for the aforementioned characteristic formulations is still an open problem.
description: 20 pages, 11 figures, 2 tables, data and code can be found at http://dx.doi.org/10.5281/zenodo.7981429 and https://github.com/ThanasisGiannakopoulos/model_CCE_CCM_public, updated to match published version
Additional file 1 of A novel protein encoded by circFNDC3B inhibits tumor progression and EMT through regulating Snail in colon cancer
Creators: name: Pan, Zihao
name: Cai, Jianye
name: Lin, Jiatong
name: Zhou, Huinian
name: Peng, Jingwen
name: Liang, Jinliang
name: Xia, Long
name: Yin, Qi
name: Zou, Baojia
name: Zheng, Jun
name: Qiao, Liang
name: Zhang, Lei
Publisher: name: figshare
Year: 2020
Subjects: subject: Biochemistry
subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Pharmacology
subject: Chemical Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Cancer
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: Additional file 1: Table S1. The primer sequences used in this study.
Correlated variables in regression: clustering and sparse estimation
Creators: name: Bühlmann, Peter
name: Rütimann, Philipp
name: van de Geer, Sara
name: Zhang, Cun-Hui
Publisher: name: arXiv
Year: 2012
Subjects: subject: Methodology (stat.ME)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: 62J07, 62H30

description: We consider estimation in a high-dimensional linear model with strongly correlated variables. We propose to cluster the variables first and do subsequent sparse estimation such as the Lasso for cluster-representatives or the group Lasso based on the structure from the clusters. Regarding the first step, we present a novel and bottom-up agglomerative clustering algorithm based on canonical correlations, and we show that it finds an optimal solution and is statistically consistent. We also present some theoretical arguments that canonical correlation based clustering leads to a better-posed compatibility constant for the design matrix which ensures identifiability and an oracle inequality for the group Lasso. Furthermore, we discuss circumstances where cluster-representatives and using the Lasso as subsequent estimator leads to improved results for prediction and detection of variables. We complement the theoretical analysis with various empirical results.
description: 40 pages, 6 figures
Nonlinear optical pulses in media with asymmetric gain
Creators: name: Turitsyn, Sergei K.
name: Bednyakova, Anastasia E.
name: Podivilov, Evgeniy V.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: A generic novel model governing optical pulse propagation in a nonlinear dispersive amplifying medium with asymmetric (linear spectral slope) gain is introduced. We examine the properties of asymmetric optical pulses formed in such gain-skewed media, both theoretically and numerically. We derive a dissipative optical modification of the classical shallow water equations that highlights an analogy between this phenomenon and hydrodynamic wave-breaking. We observe the development of spectral optical shock waves, and discuss the conditions and origins of this spectral wave-breaking in media with asymmetric gain. These findings provide insight into the nature of asymmetric optical pulses capable of accumulating large nonlinear phase without wave-breaking, a crucial aspect in the design of nonlinear fiber amplifiers.
description: 11 pages, 10 figures
Heterogeneous Winter Wheat Populations Differ in Yield Stability Depending on their Genetic Background and Management System
Creators: name: Weedon, Odette Denise
name: Finckh, Maria Renate
Publisher: name: Universität Kassel
Year: 2019
Subjects: subject: heterogeneous populations
subject: winter wheat
subject: yield stability
subject: organic and conventional management
subject: genetic diversity
subject: 630

description: Gefördert durch den Publikationsfonds der Universität Kassel
Deliverable 2.7 BlockStart DLT Assessment Tool - Final Version
Creators: name: UAB CIVITTA
Publisher: name: Zenodo
Year: 2021
Subjects: blockchain
startups
end-users
fintech
ict
retail
dlt
assessment

description: BlockStart project has created and published a DLT Assessment Tool, which aims to evaluate SMEs/ startups capacity and potential to start using the technology. The first version of the DLT Assessment Tool was made available in BlockStart’s website (www.blockstart.eu/dlt/) in M4 of the project (December 2019) and has been updated according to the insights from internal and external discussions with the consortium partners and experts that participated in the programme. This deliverable overviews the main insights from the previous version of the tool, the changes made to the updated version as well as the traction and responses collected from the introduction of the updated tool in M10 until this point (M23, roughly 13 months). Since the last iteration in M10, no significant changes have been made to the content and questions of the tool. This allows us to collect a larger amount of significant responses and statistical data, outlined in detail below. The DLT Assessment Tool has been published using Typeform’s platform, due to its convenient functionality and user-friendliness. The platform allows building custom logic on the questions flow based on the answers. It also provides useful statistics on the drop-off rate and allows the questionnaire to be embedded into the BlockStart’s website.
Black holes and the loss landscape in machine learning
Creators: name: Kumar, Pranav
name: Mandal, Taniya
name: Mondal, Swapnamay
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Understanding the loss landscape is an important problem in machine learning. One key feature of the loss function, common to many neural network architectures, is the presence of exponentially many low lying local minima. Physical systems with similar energy landscapes may provide useful insights. In this work, we point out that black holes naturally give rise to such landscapes, owing to the existence of black hole entropy. For definiteness, we consider 1/8 BPS black holes in $\mathcal{N} = 8$ string theory. These provide an infinite family of potential landscapes arising in the microscopic descriptions of corresponding black holes. The counting of minima amounts to black hole microstate counting. Moreover, the exact numbers of the minima for these landscapes are a priori known from dualities in string theory. Some of the minima are connected by paths of low loss values, resembling mode connectivity. We estimate the number of runs needed to find all the solutions. Initial explorations suggest that Stochastic Gradient Descent can find a significant fraction of the minima.
description: 32 pages, 4 figures
F-Theory and the Mordell-Weil Group of Elliptically-Fibered Calabi-Yau Threefolds
Creators: name: Morrison, David R.
name: Park, Daniel S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The Mordell-Weil group of an elliptically fibered Calabi-Yau threefold X contains information about the abelian sector of the six-dimensional theory obtained by compactifying F-theory on X. After examining features of the abelian anomaly coefficient matrix and U(1) charge quantization conditions of general F-theory vacua, we study Calabi-Yau threefolds with Mordell-Weil rank-one as a first step towards understanding the features of the Mordell-Weil group of threefolds in more detail. In particular, we generate an interesting class of F-theory models with U(1) gauge symmetry that have matter with both charges 1 and 2. The anomaly equations --- which relate the Neron-Tate height of a section to intersection numbers between the section and fibral rational curves of the manifold --- serve as an important tool in our analysis.
description: 29 pages + appendices, 5 figures; v2: minor corrections
RECOMS_ESR09
Creators: name: Vezzoni, Ruben
Publisher: name: Zenodo
Year: 2021

description: Description of the RECOMS ESR09 project: In Europe there are areas with substantial green infrastructure and resources, but few people. As well as being sparsely populated, these areas are also often difficult to access. This project explores the ways in which communities within such spaces address the interdependence and coevolution of green and blue economies and ecosystem services through enterprising forms of collaborative and resourceful practice. Special attention is paid to the actions and learning that take place in the multi-layered networks of citizens, their associations, private and public sector organisations and political decision makers. This includes their identification of ways to safeguard the resilience of these places whilst simultaneously also utilizing the green and blue assets for local and wider societal returns. The research investigates economic mechanisms which support community-led environmental action, especially social investment.
Flat bands and magnetism in $\mathrm{\mathbf{Fe_4 Ge Te_2}}$ and $\mathrm{\mathbf{Fe_5GeTe_2}}$ due to bipartite crystal lattices
Creators: name: Wang, Fuyi
name: Zhang, Haijun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: $\mathrm{Fe_{n=4,5}GeTe_2}$ exhibits quasi-two-dimensional properties as a promising candidate for a near-room-temperature ferromagnet, which has attracted great interest. In this work, we notice that the crystal lattice of $\mathrm{Fe_{n=4,5}GeTe_2}$ can be approximately regarded as being stacked by three bipartite crystal lattices. By combining the model Hamiltonians of bipartite crystal lattices and first-principles calculations, we investigate the electronic structure and the magnetism of $\mathrm{Fe_{n=4,5}GeTe_2}$. We conclude that flat bands near the Fermi level originate from the bipartite crystal lattices and that these flat bands are expected to lead to the itinerant ferromagnetism in $\mathrm{Fe_{n=4,5}GeTe_2}$. Interestingly, we also find that the magnetic moment of the Fe5 atom in $\mathrm{Fe_5 Ge Te_2}$ is distinct from the other Fe atoms and is sensitive to the Coulomb interaction $U$ and external pressure. These findings may be helpful to understand the exotic magnetic behavior of $\mathrm{Fe_{n=4,5} Ge Te_2}$.
description: 10 pages, 8 figures
Exact results for classical Casimir interactions: Dirichlet and Drude model in the sphere-sphere and sphere-plane geometry
Creators: name: Bimonte, G.
name: Emig, T.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Analytic expressions that describe Casimir interactions over the entire range of separations have been limited to planar surfaces. Here we derive analytic expressions for the classical or high-temperature limit of Casimir interactions between two spheres (interior and exterior configurations), including the sphere-plane geometry as a special case, using bispherical coordinates. We consider both Dirichlet boundary conditions and metallic boundary conditions described by the Drude model. At short distances, closed-form expansions are derived from the exact result, displaying an intricate structure of deviations from the commonly employed proximity force approximation.
description: 5 pages, 2 figures
Azimuthal angular correlations between heavy-flavour decay electrons and charged hadrons in pp collisions at $\sqrt{s} = 2.76$ TeV in ALICE
Creators: name: Thomas, Deepa
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: In ultra-relativistic heavy-ion collisions heavy quarks (charm and beauty) are produced in hard scattering processes and thus carry relevant information on the properties of the created hot and dense medium. Heavy-flavour hadrons can be measured using electrons from their semileptonic decay channels. The relative contribution of charm and beauty hadrons can be estimated from the study of the near side azimuthal angular correlations between these electrons and charged hadrons. We present the measurement of azimuthal angular correlations between electrons and charged hadrons in pp collisions at 2.76 TeV measured with ALICE at the LHC. Electrons are identified using the Electromagnetic Calorimeter and the Time Projection Chamber and the charged hadrons are identified using the Time Projection Chamber. The azimuthal angular correlation distributions from PYTHIA simulations are used to extract the relative contribution from B-hadron decays to the yield of electrons from heavy-flavour decays up to $p_\textrm{t}$ = 10 GeV/c.
Suberea etiennei Van Soest, Kaiser & Van Syoc 2011
Creators: name: Trejo, Alejandra
name: Carballo, José Luis
name: Segovia, Johanna
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Demospongiae
Verongiida
Aplysinellidae
Suberea
Suberea etiennei

description: Suberea etiennei Soest, Kaiser & Van Syoc, 2011
Figure 10, Table 10
Examined material. MUHNES-91-51— El Bajón de Zúniga I (13°30’16.15”N, 89°47’7.4”W), depth 9 m, A. Trejo (18.VII.2018).
Description. Pale yellow sponge in life, after preservation it turned violet-black, it does not have a specific morphology and has a low proportion of fibers compared to the organic material, it is soft and irregular to touch (Figure 10A). It presents mostly dichotomous dendritic fibers that divide irregularly and much more frequently when approaching the surface. The fibers are thin (35–90 µm) compared to other species of the same genus, the pith is dark and granular, occupying between 43–75% of the fiber (Figure 10B–C).
Ecological notes. The species was found attached to large rocks and surrounded by turf at 9 m depth.
Distribution and previous records. The species was described by Van Soest et al. in 2011 from Clipperton Islands. Here we report it for the first time in Central America (Table 12).
Remarks. The specimen shares the common characteristics of the genus Suberea as the low proportion of fibers compared to the soft tissue. We state that the specimen belongs to S. etiennei because it has very thin fibers and the proportion of the pith is similar to the original description (Van Soest et al. 2011). There are only two species of Suberea described from the eastern Pacific: S. etiennei from Clipperton Islands, and S. esmerelda Sim-Smith, Hickman Jr & Kelly, 2021 from Galapagos Islands, this species differs with our specimen because of its morphological external characteristics as a massive and multilobate sponge with large conspicuous oscules at the ápex of the lobes, also its color in life is dull yellow to greenish grey (Sim-Smith et al. 2021).
description: Published as part of Trejo, Alejandra, Carballo, José Luis & Segovia, Johanna, 2025, New records and checklist of sponges from El Salvador (Eastern Tropical Pacific), pp. 99-125 in Zootaxa 5613 (1) on pages 115-116, DOI: 10.11646/zootaxa.5613.1.4, http://zenodo.org/record/15216236
Transformation of 2-line ferrihydrite to goethite at alkaline pH
Creators: name: Furcas, Fabio E.
name: Lothenbach, Barbara
name: Mundra, Shishir
name: Borca, Camelia
name: Albert, Cristhiana C.
name: Isgor, O. Burkan
name: Huthwelker, Thomas
name: Angst, Ueli M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The transformation of 2-line ferrihydrite to goethite from supersaturated solutions at alkaline pH >= 13.0 was studied using a combination of benchtop and advanced synchrotron techniques such as X-ray diffraction, thermogravimetric analysis and X-ray absorption spectroscopy. In comparison to the transformation rates at acidic to mildly alkaline environments, the half-life,t_1/2, of 2-line ferrihydrite reduces from several months at pH = 2.0, and approximately 15 days at pH = 10.0, to just under 5 hours at pH = 14.0. Calculated first order rate constants of transformation, k, increase exponentially with respect to the pH and follow the progression log_10 k = log_10 k_0 + a*pH^E3. Simultaneous monitoring of the aqueous Fe(III) concentration via inductively coupled plasma optical emission spectroscopy demonstrates that (i) goethite likely precipitates from solution and (ii) its formation is rate-limited by the comparatively slow re-dissolution of 2-line ferrihydrite. The analysis presented can be used to estimate the transformation rate of naturally occurring 2-line ferrihydrite in aqueous electrolytes characteristic to mine and radioactive waste tailings as well as the formation of corrosion products in cementitious pore solutions.
Peculiarities of beta functions in sigma models
Creators: name: Gamayun, Oleksandr
name: Losev, Andrei
name: Shifman, Mikhail
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: In this paper we consider perturbation theory in generic two-dimensional sigma models in the so-called first-order formalism, using the coordinate regularization approach. Our goal is to analyze the first-order formalism in application to $β$ functions and compare its results with the standard geometric calculations. Already in the second loop, we observe deviations from the geometric results that cannot be explained by the regularization/renormalization scheme choices. Moreover, in certain cases the first-order calculations produce results that are not symmetric under the classical diffeomorphisms of the target space. Although we could not present the full solution to this remarkable phenomenon, we found some indirect arguments indicating that an anomaly similar to that established in supersymmetric Yang-Mills theory might manifest itself starting from the second loop. We discuss why the difference between two answers might be an infrared effect, similar to that in $β$ functions in supersymmetric Yang-Mills theories. In addition to the generic Kähler target spaces we discuss in detail the so-called Lie-algebraic sigma models. In particular, this is the case when the perturbed field $G^{i\bar j}$ is a product of the holomorphic and antiholomorphic currents satisfying two-dimensional current algebra.
description: 31 pages, 2 figures
Symmetry-Resolved Entanglement: General considerations, calculation from correlation functions, and bounds for symmetry-protected topological phases
Creators: name: Monkman, K.
name: Sirker, J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We discuss some general properties of the symmetry-resolved von-Neumann entanglement entropy in systems with particle number conservation and describe how to obtain the entanglement components from correlation functions for Gaussian systems. We introduce majorization as an important tool to derive entanglement bounds. As an application, we derive lower bounds both for the number and the configurational entropy for chiral and Cn-symmetric topological phases. In some cases, our considerations also lead to an improvement of the previously known lower bounds for the entanglement entropy in such systems.
description: 20 pages
EUV and HXR Signatures of Electron Acceleration During the Failed Eruption of a Filament
Creators: name: Netzel, A.
name: Mrozek, T.
name: Kolomanski, S.
name: Gburek, S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We search for EUV brightenings in TRACE 171 Å images and HXR bursts observed during failed eruptions. We expect that if an eruption is confined due to interaction with overlying magnetic structures then we should observe effects connected with reconnection between magnetic structures and acceleration of particles. We utilized TRACE observations of three well observed failed eruptions. EUV images were compared to HXR spatial distribution reconstructed from Yohkoh/HXT and RHESSI data. The EUV light curves of a selected area were compared to height profiles of eruption, HXR emission and HXR photon spectral index of power-law fit to HXR data. We have found that EUV brightenings are closely related to the eruption velocity decrease, to HXR bursts and to episodes of hardening of HXR spectra. The EUV brightened areas are observed far from the flaring structure, in footpoints of large systems of loops observed 30-60 minutes after the maximum of a flare. These are not `post-flare' loops that are also observed but at significantly lower heights. The high lying systems of loops are observed at heights equal to height, at which eruption was observed to stop. We observed HXR source spatially correlated with EUV brightening only once. For other EUV brightened areas we estimated the expected brightness of HXR sources. We find that EUV brightenings are produced due to interaction between the erupting structure with overlying loops. The interaction is strong enough to heat the system of high loops. These loops cool down and are visible in EUV range about 30-60 minutes later. The estimated brightness of HXR sources associated with EUV brightenings shows that they are too weak to be detected with present instruments. However, next generation instruments will have enough dynamic range and sensitivity to enable such observations.
description: A&A accepted