cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Measuring the Obliquities of the TRAPPIST-1 Planets with MAROON-X
Creators: name: Brady, Madison
name: Bean, Jacob
name: Seifahrt, Andreas
name: Kasper, David
name: Luque, Rafael
name: Reiners, Ansgar
name: Benneke, Björn
name: Stefánsson, Guðmundur
name: Stürmer, Julian
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: A star's obliquity with respect to its planetary system can provide us with insight into the system's formation and evolution, as well as hinting at the presence of additional objects in the system. However, M dwarfs, which are the most promising targets for atmospheric follow-up, are underrepresented in terms of obliquity characterization surveys due to the challenges associated with making precise measurements. In this paper, we use the extreme-precision radial velocity spectrograph MAROON-X to measure the obliquity of the late M dwarf TRAPPIST-1. With the Rossiter-McLaughlin effect, we measure a system obliquity of $-2^{+17}_{-19}$ degrees and a stellar rotational velocity of 2.1 $\pm$ 0.3 km s$^{-1}$. We were unable to detect stellar surface differential rotation, and we found that a model in which all planets share the same obliquity was favored by our current data. We were unable to make a detection of the signatures of the planets using Doppler tomography, which is likely a result of the both the slow rotation of the star and the low SNR of the data. Overall, TRAPPIST-1 appears to have a low obliquity, which could imply that the system has a low primordial obliquity. It also appears to be a slow rotator, which is consistent with past characterizations of the system and estimates of the star's rotation period. The MAROON-X data allow for a precise measurement of the stellar obliquity through the Rossiter-McLaughlin effect, highlighting the capabilities of MAROON-X and its ability to make high-precision RV measurements around late, dim stars.
description: 18 pages, 6 figures, submitted to AJ
The role of potassium orbitals in the metallic behavior of K3picene
Creators: name: Chiappe, G.
name: Louis, E.
name: Guijarro, A.
name: San-Fabian, E.
name: Verges, J. A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Detailed electronic structure calculations of picene clusters doped by potassium modeling the crystalline K3picene structure show that while two electrons are completely transferred from potassium atoms to the LUMO of pristine picene, the third one remains closely attached to both material components. Multiconfigurational analysis is necessary to show that many structures of almost degenerate total energies compete to define the cluster ground state. Our results prove that the 4s orbital of potassium should be included in any interaction model describing the material. We propose a quarter filled two orbital model as the most simple model capable of describing the electronic structure of K-intercalated picene. Precise solutions obtained by a development of Lanczos method show low energy electronic excitations involving orbitals located at different positions. Consequently, metallic transport is possible in spite of the clear dominance of interaction over hopping.
description: 12 pages, 10 figures (6 of them really heavy)
Heavy and light meson wavefunctions
Creators: name: Wu, Xing-Gang
name: Huang, Tao
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a short review on the properties of heavy and light mesons' light-cone wavefunctions (LCWFs), and their distribution amplitudes (DAs). The B meson LCWFs can be treated by taking the heavy quark limit ($m_b\to\infty$) and by using the heavy quark effective theory. Furthermore, we propose a simple model for the B meson WFs with 3-particle Fock states' contributions, whose behaviors are controlled by two parameters $\barΛ$ and $δ$. Using such model, the form factors $F^{B\toπ}_{+,0,T}$ and $F^{B\to K}_{+,0,T}$ in large recoil region are studied up to ${\cal O}(1/m_b^2)$ within the $k_T$ factorization approach. On the other hand, we adopt Brodsky-Huang-Lepage (BHL) prescription for constructing the WFs of the lighter pseudoscalars as $η_c$, D-meson, pion, kaon, $η^{(\prime)}$ and etc. Such BHL-like model can be conveniently extended to construct the LCWFs for light scalar or vector mesons. Within such model the longitudinal distributions of those WFs are basically determined by a parameter $B$, whose value can be determined via a global fit of experimental data.
description: 15 pages, 12 figures. References updated. To be published in Chinese Science Bulletin
CLASS Survey Description: Coronal Line Needles in the SDSS Haystack
Creators: name: Reefe, Michael
name: Sexton, Remington O.
name: Doan, Sara M.
name: Satyapal, Shobita
name: Secrest, Nathan J.
name: Cann, Jenna M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Coronal lines are a powerful, yet poorly understood, tool to identify and characterize Active Galactic Nuclei (AGNs). There have been few large scale surveys of coronal lines in the general galaxy population in the literature so far. Using a novel pre-selection technique with a flux-to-RMS ratio $F$, followed by Markov-Chain Monte Carlo (MCMC) fitting, we searched for the full suite of 20 coronal lines in the optical spectra of almost 1 million galaxies from the Sloan Digital Sky Survey (SDSS) Data Release 8. We present a catalog of the emission line parameters for the resulting 258 galaxies with detections. The Coronal Line Activity Spectroscopic Survey (CLASS) includes line properties, host galaxy properties, and selection criteria for all galaxies in which at least one line is detected. This comprehensive study reveals that a significant fraction of coronal line activity is missed in past surveys based on a more limited set of coronal lines; $\sim$60% of our sample do not display the more widely surveyed [Fe X] $λ$6374. In addition, we discover a strong correlation between coronal line and WISE W2 luminosities, suggesting that the mid-infrared flux can be used to predict coronal line fluxes. For each line we also provide a confidence level that the line is present, generated by a novel neural network, trained on fully simulated data. We find that after training the network to detect individual lines using 100,000 simulated spectra, we achieve an overall true positive rate of 75.49% and a false positive rate of only 3.96%.
description: 27 pages, 16 figures, 4 tables
A Mixture of Bose and Fermi Superfluids
Creators: name: Ferrier-Barbut, Igor
name: Delehaye, Marion
name: Laurent, Sebastien
name: Grier, Andrew T.
name: Pierce, Matthieu
name: Rem, Benno S.
name: Chevy, Frédéric
name: Salomon, Christophe
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: Superconductivity and superfluidity of fermionic and bosonic systems are remarkable many-body quantum phenomena. In liquid helium and dilute gases, Bose and Fermi superfluidity has been observed separately, but producing a mixture in which both the fermionic and the bosonic components are superfluid is challenging. Here we report on the observation of such a mixture with dilute gases of two Lithium isotopes, 6Li and 7Li. We probe the collective dynamics of this system by exciting center-of-mass oscillations that exhibit extremely low damping below a certain critical velocity. Using high precision spectroscopy of these modes we observe coherent energy exchange and measure the coupling between the two superfluids. Our observations can be captured theoretically using a sum-rule approach that we interpret in terms of two coupled oscillators.
3D Lovelock Gravity and the Holographic c-Theorem
Creators: name: Alkac, Gokhan
name: Suer, Gun
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We show that the scalar-tensor theory that arises in a rigorous $D \to 3$ limit of Lovelock gravity up to cubic order admits a holographic c-theorem and verify that the value of the c-function at the UV fixed point matches with the Weyl anomaly coefficient (up to an irrelevant factor). The constructed c-function is the same as one that follows from the "naive limit", which is obtained by scaling the couplings by a factor of $\frac{1}{D-3}$, and then setting $D=3$.
description: 9 pages; v2: minor changes; v3: more minor changes, version to appear in PRD
Tensor Mode Backreaction During Slow-roll Inflation
Creators: name: Marozzi, G.
name: Vacca, G. P.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider the backreaction of the long wavelength tensor modes produced during a slow-roll inflationary regime driven by a single scalar field in a spatially flat Friedmann-Lema\^ıtre-Robertson-Walker background geometry. We investigate the effects on non-local observables such as the effective (averaged) expansion rate and equation of state at second order in cosmological perturbation theory. The coupling between scalar and tensor perturbations induces at second order new tensor backreaction terms beyond the one already present in a de Sitter background. We analyze in detail the effects seen by the class of observers comoving with the inflaton field (taken as a clock) and the class of free-falling observers. In both cases the quantum backreaction is at least $1/ε$ (with $ε$ the slow-roll parameter) larger than the one which can be naively inferred from a de Sitter background. In particular, we compute the effect for a free massive inflaton model and obtain in both cases a quantum correction on the background expansion rate of the order of $H^4/(m^2 M_{Pl}^2)$. A short discussion on the issue of the breakdown of perturbation theory is given.
description: 6 pages, no figures. Comments, equations and a reference added, typos corrected, some rewording made. Version accepted for publication in PRD
Diffusion with stochastic resetting screened by a semipermeable interface
Creators: name: Bressloff, Paul C
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: In this paper we consider the diffusive search for a bounded target $Ω\in \R^d$ with its boundary $\partial Ω$ totally absorbing. We assume that the target is surrounded by a semipermeable interface given by the closed surface $\partial \calM$ with $Ω\subset \calM\subset \R^d$. That is, the interface totally surrounds the target and thus partially screens the diffusive search process. We also assume that the position of the diffusing particle (searcher) randomly resets to its initial position $\x_0$ according to a Poisson process with a resetting rate $r$. The location $\x_0$ is taken to be outside the interface, $\x_0\in \calM^c$, which means that resetting does not occur when the particle is within the interior of $\partial \calM$. Hence, the semipermeable interface also screens out the effects of resetting. We first solve the boundary value problem (BVP) for diffusion on the half-line $x\in [0,\infty)$ with an absorbing boundary at $x=0$, a semipermeable barrier at $x=L$, and stochastic resetting to $x_0>L$ for all $x>L$. We calculate the mean first passage time (MFPT) to be absorbed by the target and explore its behavior as a function of the permeability $κ_0$ of the interface and its spatial position $L$. We then perform the analogous calculations for a three-dimensional (3D) spherically symmetric interface and target, and show that the MFPT exhibits the same qualitative behavior as the 1D case. Finally, we introduce a stochastic single-particle realization of the search process based on a generalization of so-called snapping out BM. The latter sews together successive rounds of reflecting Brownian motion on either side of the interface. The main challenge is establishing that the probability density generated by the snapping out BM satisfies the permeable boundary conditions at the interface. We show how this can be achieved using renewal theory.
description: 23 pages, 8 figures
Online Lernverlaufsmessung für alle SchülerInnen in inklusiven Klassen. www.levumi.de
Creators: name: Gebhardt, Markus
name: Diehl, K.
name: Mühling, A.
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: 370 Erziehung, Schul- und Bildungswesen

description: Mit der Entwicklung zu einer inklusiven Schule sind erhebliche Veränderungen verbunden. Eine zentrale Herausforderung für Lehrkräfte der Allgemeinen Schule und Förderschullehrkräfte stellt dabei der gemeinsame Unterricht von Kindern mit sonderpädagogischen und ohne sonderpädagogischen Förderbedarf dar. Wie gelingt es, Leistungen und Leistungsentwicklungen der Kinder valide einzuschätzen? Wie können Lernlücken oder Stagnationen frühzeitig erkannt werden und Lernentwicklungen durch angemessene Förderung unterstützt werden? Eine mögliche Antwort auf diese Fragen, bietet die Lern verlaufsdiagnostik. In diesem Beitrag wird die Onlineplattform LEVUMI vorgestellt. Sie bietet rechnergestützt kurze, leicht zu handhabende Messverfahren an – sog. curriculumbasierte Tests, mittels derer Lehrkräfte Einblick in Lernverläufe der Schülerinnen und Schüler im Bereich Lesen (Anfangsunterricht) erhalten. Die Ergebnisse der Lernfortschrittsdiagnostik bietet die Grundlage für eine darauf abgestimmte Förderung. Zudem erhält die Lehrkraft Rückmeldung zur Wirksamkeit ihres pädagogischen Handelns. Die bisherigen statistischen Überprüfungen der LEVUMI Testverfahren in Hinblick auf die Reliabilität sind positiv und unterstützen die weitere Arbeit und Entwicklung der Onlineplattform LEVUMI.
Probing the Top-Yukawa Coupling in Associated Higgs production with a Single Top Quark
Creators: name: Chang, Jung
name: Cheung, Kingman
name: Lee, Jae Sik
name: Lu, Chih-Ting
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Associated production of the Higgs boson with a single top quark proceeds through Feynman diagrams, which are either proportional to the hWW, top-Yukawa, or the bottom-Yukawa couplings. It was shown in literature that the interference between the top-Yukawa and the gauge-Higgs diagrams can be significant, and thus the measurement of the cross sections can help pin down the sign and the size of the top-Yukawa coupling. Here we perform a detailed study with full detector simulations of such a possibility at the LHC-14 within the current allowed range of hWW and top-Yukawa couplings, using h-> b b-bar, γγ, τ+ τ-, ZZ* -> 4 l modes. We found that the LHC-14 has the potential to distinguish the size and the sign of the top-Yukawa coupling. Among the channels the h-> b b-bar mode mode provides the best chance to probe the signal, followed by the h -> γγ mode, which has the advantage of a narrow reconstructed mass peak. We also pointed out that the spatial separation among the final-state particles has the potential in differentiating among various values of the top-Yukawa coupling.
description: 28 pages, 13 figures; a comment about NLO correction is added, references added; match the published version
Backscatter analysis based algorithms for increasing transmission through highly-scattering random media using phase-only modulated wavefronts
Creators: name: Jin, Curtis
name: Nadakuditi, Raj Rao
name: Michielssen, Eric
name: Rand, Stephen
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optics (physics.optics)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Recent theoretical and experimental advances have shed light on the existence of so-called `perfectly transmitting' wavefronts with transmission coefficients close to 1 in strongly backscattering random media. These perfectly transmitting eigen-wavefronts can be synthesized by spatial amplitude and phase modulation. Here, we consider the problem of transmission enhancement using phase-only modulated wavefronts. We develop physically realizable iterative and non-iterative algorithms for increasing the transmission through such random media using backscatter analysis. We theoretically show that, despite the phase-only modulation constraint, the non-iterative algorithms will achieve at least about 25$π$% or about 78.5% transmission assuming there is at least one perfectly transmitting eigen-wavefront and that the singular vectors of the transmission matrix obey a maximum entropy principle so that they are isotropically random. We numerically analyze the limits of phase-only modulated transmission in 2-D with fully spectrally accurate simulators and provide rigorous numerical evidence confirming our theoretical prediction in random media with periodic boundary conditions that is composed of hundreds of thousands of non-absorbing scatterers. We show via numerical simulations that the iterative algorithms we have developed converge rapidly, yielding highly transmitting wavefronts using relatively few measurements of the backscatter field. Specifically, the best performing iterative algorithm yields approx 70% transmission using just 15-20 measurements in the regime where the non-iterative algorithms yield approximately 78.5% transmission but require measuring the entire modal reflection matrix.
description: Revised version contains results of additional simulations
Stability of $φ^4$-vector model: four-loop $\varepsilon$ expansion study
Creators: name: Adzhemyan, L. Ts.
name: Kudlis, A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The stability of $O(n)$-symmetric fixed point regarding the presence of vector-field term ($\sim h p_αp_β$) in the $φ^4$ field theory is analyzed. For this purpose, the four-loop renormalization group expansions in $d=4-2\varepsilon$ within Minimal Subtraction (MS) scheme are obtained. This frequently neglected term in the action requires a detailed and accurate study on the issue of existing of new fixed points and their stability, that can lead to the possible change of the corresponding universality class. We found that within lower order of perturbation theory the only $O(n)$-symmetric fixed point $(g_{\text{H}},h=0)$ exists but the corresponding positive value of stability exponent $ω_h$ is tiny. This led us to analyze this constant in higher orders of perturbation theory by calculating the 4-loop contributions to the $\varepsilon$ expansion for $ω_h$, that should be enough to infer positivity or negativity of this exponent. The value turned out to be undoubtedly positive, although still small even in higher loops: $0.0156(3)$. These results cause that the corresponding vector term should be neglected in the action when analyzing the critical behaviour of $O(n)$-symmetric model. At the same time, the small value of the $ω_h$ shows that the corresponding corrections to the critical scaling are significant in a wide range.
Collisionless Reconnection in the Large Guide Field Regime: Gyrokinetic Versus Particle-in-Cell Simulations
Creators: name: TenBarge, J. M.
name: Daughton, W.
name: Karimabadi, H.
name: Howes, G. G.
name: Dorland, W.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Results of the first validation of large guide field, $B_g / δB_0 \gg 1$, gyrokinetic simulations of magnetic reconnection at a fusion and solar corona relevant $β_i = 0.01$ and solar wind relevant $β_i = 1$ are presented, where $δB_0$ is the reconnecting field. Particle-in-cell (PIC) simulations scan a wide range of guide magnetic field strength to test for convergence to the gyrokinetic limit. The gyrokinetic simulations display a high degree of morphological symmetry, to which the PIC simulations converge when $β_i B_g / δB_0 \gtrsim 1$ and $B_g / δB_0 \gg 1$. In the regime of convergence, the reconnection rate, relative energy conversion, and overall magnitudes are found to match well between the PIC and gyrokinetic simulations, implying that gyrokinetics is capable of making accurate predictions well outside its regime of formal applicability. These results imply that in the large guide field limit many quantities resulting from the nonlinear evolution of reconnection scale linearly with the guide field.
description: 5 pages, 4 figures, accepted as PoP letter
A study of oxygen-rich post-AGB stars in the Milky Way to understand the production of silicates from evolved stars
Creators: name: Dell'Agli, F.
name: Tosi, S.
name: Kamath, D.
name: Ventura, P.
name: Van Winckel, H.
name: Marini, E.
name: Marchetti, T.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The study of post asymptotic giant branch (post-AGB) stars is a valuable tool to study still poorly known aspects of the evolution of the stars through the AGB. This is due to the accurate determination of their surface chemical composition and to the peculiar shape of the SED: the emission from the central star can be easily disentangled from the contribution from the dusty shell, which can then be characterized. The goal of the present study is to reconstruct the dust formation process and more generally the late phases of the evolution of O-rich stars across the AGB phase. This is performed by studying O-rich, post-AGB stars, which are analyzed in terms of their luminosity, Teff and infrared excess. We study sources classified as single, O-rich, post-AGB stars in the Galaxy, which exhibit a double-peaked (shell-type) SED. We use results from stellar evolution modelling combined with dust formation and radiative transfer modelling to reconstruct the late AGB phases and the initial contraction to the post-AGB phase. We also determine the mass-loss and dust formation rates for stars of different mass and chemical composition. The analysis of the IR excess of the post-AGB, O-rich stars examined in this study outlines an interesting complexity, in terms of the correlation between the dust in the surroundings of the stars, the evolutionary status and the progenitor's mass. The sources descending from massive AGBs (>3Msun depending on metallicity) are generally characterized by higher IR excess than the lower mass counterparts, owing to the more intense dust formation taking place during the final AGB phases. From the determination of the location of the dusty regions we deduce that the expanding velocities of the outflow change significantly from star to star. The possibility that radiation pressure is unable to accelerate the wind in the faintest objects is also commented.
description: 11 pages, 6 figures and 1 table. Accepted for publication in A&A
Blue-Cloud D6.6 Fact Sheets for cluster projects and other core initiatives (Release 2)
Creators: name: Giuffrida, Rita
Publisher: name: Zenodo
Year: 2023
Subjects: Fact sheets

description: Since the start of the Blue-Cloud project in October 2019, Blue-Cloud has achieved significant results. Blue-Cloud Open Science platform introduced a "de facto" federation taking place at 3 levels: the data, the computing resources and the analytical services. For each of them Blue-Cloud orchestrated mechanisms that successfully established interoperability and resulted in a Data Discovery and Access Service, the Virtual Research Environment and five Virtual Laboratories. Blue-Cloud working environments are serving more than 1,300 users in total spread across 20 countries. 15 services released by Blue-Cloud are now available in the EOSC marketplace. 
Creating the Blue-Cloud Open Science platform was a team-work activity. In the course of the project, Blue-Cloud established synergies in the Open Science, Blue Economy and Marine Research fields with E-infrastructures, Blue Data Infrastructures, and EU-funded projects as the project team believes that through collaboration and cooperation with initiatives operating in the same field, the value of Blue-Cloud services increases. The established synergies contributed to the design of the Blue-Cloud services, fostered the adoption of Blue-Cloud innovative open-science solutions and broadened the exploitation opportunities thus highlighting the need for long term sustainability. 
The types of synergies established span from technical collaborations that exploit the potential offered by the Blue-Cloud infrastructure (Usage and exploitation of the Blue-Cloud VRE services, of the Blue-Cloud demonstrators and VLabs, and of the Data Discovery and Access Services) to support of the development of the Blue-Cloud Roadmap to 2030, or to join communication and dissemination activities. 
This deliverable summarises the main outcomes of the collaboration with projects and infrastructures in the form of fact sheets, which are also downloadable from the Blue-Cloud website. The document is structured as follows: 

The first Chapter describes the methodology adopted to scout relevant synergies and get in contact with them. The section showcases also the types of synergies Blue-Cloud has established with research infrastructures and EU-funded initiatives. The Chapter is concluded by showing the most strategic synergies for which Blue-Cloud has signed a Memorandum of Understanding; 
The second Chapter presents the synergies established with research infrastructures and EU-funded projects in the form of fact sheets; 
The third Chapter introduces some of the synergies started in the course of Blue-Cloud that will be brought forward by the follow-up initiative Blue-Cloud 2026 
This document is the second, and last, release of the Blue-Cloud fact sheets for cluster projects and other core initiatives and represents an update of the information collected and presented in its first version (D6.1).
Adiabatic optimization without local minima
Creators: name: Jarret, Michael
name: Jordan, Stephen P.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Several previous works have investigated the circumstances under which quantum adiabatic optimization algorithms can tunnel out of local energy minima that trap simulated annealing or other classical local search algorithms. Here we investigate the even more basic question of whether adiabatic optimization algorithms always succeed in polynomial time for trivial optimization problems in which there are no local energy minima other than the global minimum. Surprisingly, we find a counterexample in which the potential is a single basin on a graph, but the eigenvalue gap is exponentially small as a function of the number of vertices. In this counterexample, the ground state wavefunction consists of two "lobes" separated by a region of exponentially small amplitude. Conversely, we prove if the ground state wavefunction is single-peaked then the eigenvalue gap scales at worst as one over the square of the number of vertices.
description: 20 pages, 1 figure. Journal version
Non-equilibrium chemistry and cooling in the diffuse interstellar medium - II. Shielded gas
Creators: name: Richings, Alexander J.
name: Schaye, Joop
name: Oppenheimer, Benjamin D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We extend the non-equilibrium model for the chemical and thermal evolution of diffuse interstellar gas presented in Richings et al. (2014) to account for shielding from the UV radiation field. We attenuate the photochemical rates by dust and by gas, including absorption by HI, H2, HeI, HeII and CO where appropriate. We then use this model to investigate the dominant cooling and heating processes in interstellar gas as it becomes shielded from the UV radiation. We consider a one-dimensional plane-parallel slab of gas irradiated by the interstellar radiation field, either at constant density and temperature or in thermal and pressure equilibrium. The dominant thermal processes tend to form three distinct regions in the clouds. At low column densities cooling is dominated by ionised metals such as SiII, FeII, FeIII and CII, which are balanced by photoheating, primarily from HI. Once the hydrogen-ionising radiation becomes attenuated by neutral hydrogen, photoelectric dust heating dominates, while CII becomes dominant for cooling. Finally, dust shielding triggers the formation of CO and suppresses photoelectric heating. The dominant coolants in this fully shielded region are H2 and CO. The column density of the HI-H2 transition predicted by our model is lower at higher density (or at higher pressure for gas clouds in pressure equilibrium) and at higher metallicity, in agreement with previous PDR models. We also compare the HI-H2 transition in our model to two prescriptions for molecular hydrogen formation that have been implemented in hydrodynamic simulations.
description: 21 pages, 7 figures, accepted for publication in MNRAS. Minor changes relative to v1. Supplementary material can be found at http://noneqism.strw.leidenuniv.nl
Exciton gating and triplet deshelving in single dye molecules excited by perovskite nanocrystal FRET antennae
Creators: name: Hofmann, Felix J.
name: Bodnarchuk, Maryna
name: Protesescu, Loredana
name: Kovalenko, Maksym
name: Lupton, John M.
name: Vogelsang, Jan
Publisher: name: Universität Regensburg
Year: 2019
Subjects: subject: 530 Physik

description: The extraordinary absorption cross section and high photoluminescence (PL) quantum yield of perovskite nanocrystals make this type of material attractive to a variety of applications in optoelectronics. For the same reasons, nanocrystals are also ideally suited to function as nanoantennae to excite nearby single dye molecules by fluorescence resonance energy transfer (FRET). Here, we demonstrate that FAPbBr3 perovskite nanocrystals, of cuboidal shape and approximately 10 nm in size, are capable of selectively exciting single cyanine 3 molecules at a concentration 100-fold higher than standard single-molecule concentrations. This FRET antenna mechanism increases the effective brightness of the single dye molecules 100-fold. Photon statistics and emission polarization measurements provide evidence for the FRET process by revealing photon antibunching with unprecedented fidelity and highly polarized emission stemming from single dye molecules. Remarkably, the quality of single-photon emission improves 1.5-fold compared to emission collected directly from the nanocrystals because the higher excited states of the dye molecule act as effective filters to multiexcitons. The same process gives rise to efficient deshelving of the molecular triplet state by reverse intersystem crossing (RISC), translating into a reduction of the PL saturation of the dye, thereby increasing the maximum achievable PL intensity of the dye by a factor of 3.
Genuinely multipartite entangled states and orthogonal arrays
Creators: name: Goyeneche, Dardo
name: Zyczkowski, Karol
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A pure quantum state of N subsystems with d levels each is called k-multipartite maximally entangled state, written k-uniform, if all its reductions to k qudits are maximally mixed. These states form a natural generalization of N-qudits GHZ states which belong to the class 1-uniform states. We establish a link between the combinatorial notion of orthogonal arrays and k-uniform states and prove the existence of several new classes of such states for N-qudit systems. In particular, known Hadamard matrices allow us to explicitly construct 2-uniform states for an arbitrary number of N>5 qubits. We show that finding a different class of 2-uniform states would imply the Hadamard conjecture, so the full classification of 2-uniform states seems to be currently out of reach. Additionally, single vectors of another class of 2-uniform states are one-to-one related to maximal sets of mutually unbiased bases. Furthermore, we establish links between existence of k-uniform states, classical and quantum error correction codes and provide a novel graph representation for such states.
description: 24 pages, 7 figures. Comments are very welcome!
Robust fractional-order fast terminal sliding mode control of aerial manipulator derived from a mutable inertia parameters model
Creators: name: Zheng, Wenlei
name: Li, Zhan
name: Xiu, Bingkai
name: Zhao, Bingliang
name: Guo, Zhigang
Publisher: name: arXiv
Year: 2022
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: The coupling disturbance between the manipulator and the unmanned aerial vehicle (UAV) deteriorates the control performance of system. To get high performance of the aerial manipulator, a robust fractional order fast terminal sliding mode control (FOFTSMC) strategy based on mutable inertia parameters is proposed in this paper. First, the dynamics of aerial manipulator with consideration of the coupling disturbance is derived by utilizing mutable inertia parameters. Then, based on the dynamic model, a robust FOFTSMC algorithm is designed to make the system fly steadily under coupling disturbance. Furthermore, stability analysis is conducted to prove the convergence of tracking errors. Finally, comparative simulation results are given to show the validity and superiority of the proposed scheme.
description: This paper has been accepted by ICBDAI2022
Der Schulbegleiter muss vom Typ her offen sein. Eine Interviewstudie zur Kooperation zwischen Lehrkräften und Schulbegleitern im Gymnasium
Creators: name: Weidenhiler, P.
name: Gebhardt, Markus
name: Gegenfurtner, Andreas
Publisher: name: Universität Regensburg
Year: 2018
Subjects: subject: Schulbegleitung, Schulassistenz, Inklusion, Integrationshilfe, Kooperation, Interviewstudie
subject: 370 Erziehung, Schul- und Bildungswesen

description: Schulbegleitung ist in vielen Schulen eine Unterstützungsmaßnahme für die inklusive Schule. Um die Kooperation zwischen Schulbegleitern und Lehrkräften in inklusiven Klassen zu betrachten, wurden drei Lehrkräfte und zwei Schulbegleiter in Gymnasien in Oberbayern interviewt. Die Auswertung zeigt, dass reguläre Lehrkräfte, nach eigenen Angaben, wenig Wissen über Sonderpädagogik und Inklusion haben und die Zusammenarbeit nur unter bestimmten Umständen gelingt.
Slow slip and the transition from fast to slow fronts in the rupture of frictional interfaces
Creators: name: Trømborg, Jørgen Kjoshagen
name: Sveinsson, Henrik Andersen
name: Scheibert, Julien
name: Thøgersen, Kjetil
name: Amundsen, David Skålid
name: Malthe-Sørenssen, Anders
Publisher: name: arXiv
Year: 2014
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Classical Physics (physics.class-ph)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: The failure of the population of micro-junctions forming the frictional interface between two solids is central to fields ranging from biomechanics to seismology. This failure is mediated by the propagation along the interface of various types of rupture fronts, covering a wide range of velocities. Among them are so-called slow fronts, which are recently discovered fronts much slower than the materials' sound speeds. Despite intense modelling activity, the mechanisms underlying slow fronts remain elusive. Here, we introduce a multi-scale model capable of reproducing both the transition from fast to slow fronts in a single rupture event and the short-time slip dynamics observed in recent experiments. We identify slow slip immediately following the arrest of a fast front as a phenomenon sufficient for the front to propagate further at a much slower pace. Whether slow fronts are actually observed is controlled both by the interfacial stresses and by the width of the local distribution of forces among micro-junctions. Our results show that slow fronts are qualitatively different from faster fronts. Since the transition from fast to slow fronts is potentially as generic as slow slip, we anticipate that it might occur in the wide range of systems in which slow slip has been reported, including seismic faults.
description: 35 pages, 5 primary figures, 6 supporting figures. Post-print version with improvements from review process included
Modeling Hadronic Gamma-ray Emissions from Solar Flares and Prospects for Detecting Non-thermal Signatures from Protostars
Creators: name: Kimura, Shigeo S.
name: Takasao, Shinsuke
name: Tomida, Kengo
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We investigate gamma-ray emission in the impulsive phase of solar flares and the detectability of non-thermal signatures from protostellar flares. Energetic solar flares emit high-energy gamma rays of GeV energies, but their production mechanism and emission site are still unknown. Young stellar objects, including protostars, also exhibit luminous X-ray flares, but the triggering mechanism of the flaring activity is still unclear due to the strong obscuration. Non-thermal signatures in mm/sub-mm and gamma-ray bands are useful to probe protostellar flares owing to their strong penetration power. We develop a non-thermal emission model of the impulsive phase of solar flares, where cosmic-ray protons accelerated at the termination shock produce high-energy gamma rays via hadronuclear interaction with the evaporation plasma. This model can reproduce gamma-ray data in the impulsive phase of a solar flare. We apply our model to protostellar flares and show that Cherenkov Telescope Array will be able to detect gamma rays of TeV energies if particle acceleration in protostellar flares is efficient. Non-thermal electrons accelerated together with protons can emit strong mm and sub-mm signals via synchrotron radiation, whose power is consistent with the energetic mm/sub-mm transients observed from young stars. Future gamma-ray and mm/sub-mm observations from protostars, coordinated with a hard X-ray observation, will unravel the non-thermal particle production and triggering mechanism of protostellar flares.
description: 19 pages, 5 figures, 1 table, accepted for publication in ApJ
Gel-Sol Transition of Thermoresponsive Poly(vinyl alcohol) Solution: Validation of the Universal Critical Scaling Relations
Creators: name: Bhattacharyya, Tulika
name: Suman, Khushboo
name: Joshi, Yogesh M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: While undergoing gelation transition, a material passes through a distinctive state called the critical gel state. In the neighborhood of this critical gel state, how viscosity, equilibrium modulus, and relaxation times evolve are correlated by scaling relations, and their universality has been validated for materials undergoing the sol to gel transition. In this work, we extend this approach for the gel to sol transition of a thermoresponsive polymeric system of aqueous Poly(vinyl alcohol) (PVOH) gel that passes through the critical state upon increasing temperature. We observe that, in the neighborhood of the critical gel state, the equilibrium modulus and viscosity demonstrate a power law dependence on the relative distance from the critical state in terms of normalized temperature. Furthermore, the relaxation times in the gel and the sol state shows symmetric power law divergence near the critical state. The corresponding critical power law exponents and the dynamic critical exponents computed at the critical gel to sol transition state validate the scaling and hyperscaling relations originally proposed for the critical sol to gel transition very well. Remarkably, the dependence of complex viscosity on frequency at different temperatures shows a comprehensive mastercurve irrespective of the temperature ramp rate independently in the gel and the sol state. This observation demonstrates how the shape of relaxation time spectrum is independent of both the temperature as well as the ramp rate. Since sol to gel as well as the gel to sol transitions are opposite to each other, the applicability of the scaling relations validated in this work suggests broader symmetry associated with how the structure evolves around the critical state irrespective of the direction.
Binary versus non-binary information in real time series: empirical results and maximum-entropy matrix models
Creators: name: Almog, Assaf
name: Garlaschelli, Diego
Publisher: name: arXiv
Year: 2014
Subjects: subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: The dynamics of complex systems, from financial markets to the brain, can be monitored in terms of multiple time series of activity of the constituent units, such as stocks or neurons respectively. While the main focus of time series analysis is on the magnitude of temporal increments, a significant piece of information is encoded into the binary projection (i.e. the sign) of such increments. In this paper we provide further evidence of this by showing strong nonlinear relations between binary and non-binary properties of financial time series. These relations are a novel quantification of the fact that extreme price increments occur more often when most stocks move in the same direction. We then introduce an information-theoretic approach to the analysis of the binary signature of single and multiple time series. Through the definition of maximum-entropy ensembles of binary matrices and their mapping to spin models in statistical physics, we quantify the information encoded into the simplest binary properties of real time series and identify the most informative property given a set of measurements. Our formalism is able to accurately replicate, and mathematically characterize, the observed binary/non-binary relations. We also obtain a phase diagram allowing us to identify, based only on the instantaneous aggregate return of a set of multiple time series, a regime where the so-called `market mode' has an optimal interpretation in terms of collective (endogenous) effects, a regime where it is parsimoniously explained by pure noise, and a regime where it can be regarded as a combination of endogenous and exogenous factors. Our approach allows us to connect spin models, simple stochastic processes, and ensembles of time series inferred from partial information.
Reconstruction from Spatio-Spectrally Coded Multispectral Light Fields
Creators: name: Schambach, Maximilian
Publisher: name: KIT Scientific Publishing
Year: 2022
Subjects: Computer Vision
Lichtfelder
Multispektrale Bildgebung
Compressed Sensing
Deep Learning
computer vision
light fields
multispectral imaging
compressed sensing
deep learning

description: In dieser Arbeit werden spektral kodierte multispektrale Lichtfelder untersucht, wie sie von einer Lichtfeldkamera mit einem spektral kodierten Mikrolinsenarray aufgenommen werden. Für die Rekonstruktion der kodierten Lichtfelder werden zwei Methoden entwickelt, eine basierend auf den Prinzipien des Compressed Sensing sowie eine Deep Learning Methode. Anhand neuartiger synthetischer und realer Datensätze werden die vorgeschlagenen Rekonstruktionsansätze im Detail evaluiert.
Primordial black holes and gravitational waves from non-canonical inflation
Creators: name: Papanikolaou, Theodoros
name: Lymperis, Andreas
name: Lola, Smaragda
name: Saridakis, Emmanuel N.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Primordial black holes (PBHs) can generically form in inflationary setups through the collapse of enhanced cosmological perturbations, providing us access to the early Universe through their associated observational signatures. In the current work we propose a new mechanism of PBH production within non-canonical inflation, using a class of steep-deformed inflationary potentials compatible with natural values for the non-canonical exponents. In particular, by requiring significant PBH production we extract constraints on the non-canonical exponents. Additionally, we find that our scenario can lead to the formation of asteroid-mass PBHs, which can account for the totality of the dark matter, as well as to production of solar-mass PBHs within the LIGO/VIRGO detection band. Finally, we find that the enhanced cosmological perturbations which collapse to form PBHs can produce a stochastic gravitational-wave (GW) background induced by second-order gravitational interactions. Very interestingly, we obtain a GW signal detectable by future GW experiments, in particular by SKA, LISA and BBO.
description: Accepted in JCAP
Impossibility of the strong magnetic fields generation in an electron-positron plasma
Creators: name: Dvornikov, Maxim
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We examine the issue whether a magnetic field can be amplified in a background matter consisting of electrons and positrons self-interacting within the Fermi model. For this purpose we compute the antisymmetric contribution to the photon polarization tensor in this matter having nonzero temperature and chemical potential. It is shown that this contribution is vanishing in the static limit. Then we study a particular case of a degenerate relativistic electron gas present in a magnetar. We demonstrate that a seed magnetic field is attenuated in this case. Thus, contrary to the recent claim, we show that there is no magnetic field instability in such a system, which can lead to the magnetic field growth. Therefore recently proposed mechanism cannot be used for the explanation of strong magnetic fields of magnetars.
description: 5 pages in Revtex4.1, 3 eps figures; title was changed, 1 new figure was added, discussion of the magnetic field evolution was included, 2 references were added, variant to be published in PRD as rapid communication
On An Identity of a Product Over the Non Trivial Zeros of the Riemann Zeta Function.pdf
Creators: name: Morozov, Ivan
Publisher: name: figshare
Year: 2020
Subjects: subject: 10199 Pure Mathematics not elsewhere classified
subject: FOS: Mathematics
subject: 10111 Real and Complex Functions (incl. Several Variables)

description: A new identity derived, relating an infinite product of an expression over the non-trivial zeros of the Riemann zeta function to the mathematical constant pi and henceforth to prime numbers.