cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Learning-Based On-Track System Identification for Scaled Autonomous Racing in Under a Minute
Creators: name: Dikici, Onur
name: Ghignone, Edoardo
name: Hu, Cheng
name: Baumann, Nicolas
name: Xie, Lei
name: Carron, Andrea
name: Magno, Michele
name: Corno, Matteo
Publisher: name: arXiv
Year: 2024
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Accurate tire modeling is crucial for optimizing autonomous racing vehicles, as state-of-the-art (SotA) model-based techniques rely on precise knowledge of the vehicle's parameters. Yet, system identification in dynamic racing conditions is challenging due to varying track and tire conditions. Traditional methods require extensive operational ranges, often impractical in racing scenarios. Machine learning (ML)-based methods, while improving performance, struggle with generalization and depend on accurate initialization. This paper introduces a novel on-track system identification algorithm, incorporating a neural network (NN) for error correction, which is then employed for traditional system identification with virtually generated data. Crucially, the process is iteratively reapplied, with tire parameters updated at each cycle, leading to notable improvements in accuracy in tests on a scaled vehicle. Experiments show that it is possible to learn a tire model without prior knowledge with only 30 seconds of driving data and 3 seconds of training time. This method demonstrates greater one-step prediction accuracy than the baseline nonlinear least squares (NLS) method under noisy conditions, achieving a 3.3x lower root mean square error (RMSE), and yields tire models with comparable accuracy to traditional steady-state system identification. Furthermore, unlike steady-state methods requiring large spaces and specific experimental setups, the proposed approach identifies tire parameters directly on a race track in dynamic racing environments.
Gas hydrate systems of the southern Hikurangi Margin, Aotearoa, New Zealand
Publisher: name: GNS Science
Year: 2018

description: The TAN1808 voyage took place between the 8th of September and the 5th of October 2018,
aboard RV Tangaroa. Geophysical data and seafloor samples were collected in several study
areas off the Wairarapa coast and further to the south, off the coast of north-eastern South
Island. Approximately 2750 line kilometres of multi-channel seismic data were acquired,
providing detailed characterisation of gas hydrate accumulations in the sub-seafloor.
Multibeam bathymetry and water column data, as well as single-beam echo-sounder data,
were acquired in tandem with seismic data. The hydro-acoustic datasets enabled detailed
mapping of seafloor morphology and backscatter character, as well as shallow sub-seafloor
imaging. A total of 93 active methane seeps were identified from multibeam water column data.
48 seafloor samples were collected using a range of sampling techniques (gravity coring, grab
sampling and dredging). These samples give new insight into seafloor composition above gas
hydrate accumulations as well as the reservoir sediments within which gas hydrates form.
Three of the seafloor samples collected were targeted for microbiological analyses of the gas
hydrate system. (auth)
Magnetic response of Pr$_{1-x}$LaCe$_x$CuO$_4$ in comparison with hole-doped cuprates
Creators: name: Sherman, A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The origin of differences in the magnetic responses of Pr$_{1-x}$LaCe$_x$CuO$_4$ with $x=0.11-0.12$ and moderately doped $p$-type cuprates is investigated using the t-J model, the Mori projection operator technique and dispersions of charge carriers derived from photoemission experiments. These differences are related to the proximity of the former crystal to the boundary of the antiferromagnetic phase and to the remoteness of $p$-type compounds from it. This leads to different nesting vectors of the low-frequency equi-energy contours of carrier dispersions in these crystals. The strong nesting with the antiferromagnetic momentum as the nesting vector produces the commensurate low-frequency response and the coexistence of two spin-excitation branches in Pr$_{1-x}$LaCe$_x$CuO$_4$, while incommensurate nesting vectors in $p$-type crystals lead to the incommensurate low-frequency response and the hourglass dispersion of susceptibility maxima.
description: 5 pages, 4 figures, Proc. of EASTMAG-2013, Vladivostok
`Analytic Continuation' of N=2 Minimal Model
Creators: name: Sugawara, Yuji
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper we discuss what theory should be identified as the `analytic continuation' with $N \rightarrow -N$ of the ${\cal N}=2$ minimal model with the central charge $\hat{c} = 1 - \frac{2}{N}$. We clarify how the elliptic genus of the expected model is written in terms of {\em holomorphic\/} linear combinations of the `modular completions' introduced in [arXiv:1012.5721 [hep-th]] in the $SL(2)_{N+2}/U(1)$-supercoset theory. We further discuss how this model could be interpreted as a kind of {\em `compactified'} model of the $SL(2)_{N+2}/U(1)$-supercoset in the $(\tilde{R},\tilde{R})$-sector, in which only the discrete spectrum appears in the torus partition function and the potential IR-divergence due to the non-compactness of target space is removed. We also briefly argue on possible definitions of the sectors with other spin structures.
description: 1+29 pages, no figure
The visibility of Lyman Alpha Emitters: constraining reionization, ionizing photons and dust
Creators: name: Hutter, A.
name: Dayal, P.
name: Partl, A. M.
name: Müller, V.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We build a physical model for high-redshift Lyman Alpha emitters (LAEs) by coupling state of the art cosmological simulations (GADGET-2) with a dust model and a radiative transfer code (pCRASH). We post-process the cosmological simulation with pCRASH using five different values of the escape fraction of hydrogen ionizing photons (f_esc=0.05,0.25,0.5,0.75,0.95) until reionization is complete, i.e. the average neutral hydrogen fraction drops to ~10^-4. Then, the only free-parameter left to match model results to the observed Lya and UV luminosity functions of LAEs at z~6.6 is the relative escape of Lyman Alpha (Lya) and continuum photons from the galactic environment (f_alpha/f_c). We find a three-dimensional degeneracy such that the theoretical model can be reconciled with observations for an IGM Lya transmission _LAE~38-50% (which translates to ~0.5-10^-4 for Gaussian emission lines), f_esc~0.05-0.50 and f_alpha/f_c~0.6-1.8.
description: 20 pages, 13 figures, 1 table, comments welcome, accepted for publication in MNRAS
A study of particle acceleration, heating, power deposition, and the damping length of kinetic Alfvén waves in non-Maxwellian coronal plasma
Creators: name: Ayaz, S.
name: Zank, Gary P.
name: Khan, Imran A.
name: Li, G.
name: Rivera, Yeimy J.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: The heating of the solar corona and solar wind, through suprathermal particles and kinetic Alfvén waves within the 0 - 10 $R_{\rm Sun}$ range, has been a subject of great interest for many decades. This study investigates the acceleration and heating of charged particles and the role of KAWs in the solar corona. We investigate how KAWs transport energy and accelerate/heat the charged particles, focusing on the behavior of perturbed EM fields, Poynting flux vectors, net power transfer, resonant particle speed, group speed, and the damping length of KAWs. The study examines how these elements are influenced by suprathermal particles κand the electron-to-ion temperature $T_e/T_i$. We use kinetic plasma theory coupled with the Vlasov-Maxwell model to investigate the dynamics of KAWs and particles. We assume a collisionless, homogeneous, and low-beta electron-ion plasma in which Alfvén waves travel in the kinetic limits. The results show the perturbed EM fields are significantly influenced by $κ$ and $T_e/T_i$. We evaluate both the parallel and perpendicular Poynting fluxes and find that the parallel Poynting flux dissipates gradually for lower κvalues. The perpendicular flux dissipates quickly over shorter distances. Power deposition in solar flux tubes is significantly influenced by κand Te/Ti. We find that particles can heat the solar corona over long distances in the parallel direction and short distances in the perpendicular direction. The group velocity of KAWs increases for lower κvalues, and the damping length is enhanced under lower κ, suggesting longer energy transport distances. These findings offer a comprehensive understanding of particle-wave interactions in the solar corona and wind, with potential applications for missions such as the Parker Solar Probe (PSP), and can also apply to other environments.
description: Accepted for publication in the Astronomy and Astrophysics (A&A) journal (2024)
DrugEx v2 pretrained model (ChEMBL31)
Creators: name: Béquignon, Olivier J. M.
Publisher: name: Zenodo
Year: 2022
Subjects: deep learning
reinforcement learning
policy gradient
drug design
multi-objective optimization
exploration strategy
pretrained model
ChEMBL

description: This SMILES-model was built with version v2 of DrugEx. The dataset used to build this model was ChEMBL version 31. This version of the model is adapted to be compatible with current DrugEx release 3.3.0.
A Gauss-Kuzmin theorem for continued fractions associated with non-positive interger powers of an integer $m \geq 2$
Creators: name: Lascu, Dan
Publisher: name: arXiv
Year: 2013
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11J70, 11K50

description: We consider a family $\{τ_m:m\geq 2\}$ of interval maps introduced by Hei-Chi Chan [5] as generalizations of the Gauss transformation. For the continued fraction expansion arising from $τ_m$, we solve its Gauss-Kuzmin-type problem by applying the method of Rockett and Szüsz [18].
description: 18 pages
Truncated affine Rozansky--Witten models as extended TQFTs
Creators: name: Brunner, Ilka
name: Carqueville, Nils
name: Roggenkamp, Daniel
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Algebra (math.QA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We construct extended TQFTs associated to Rozansky--Witten models with target manifolds $T^*\mathbb{C}^n$. The starting point of the construction is the 3-category whose objects are such Rozansky--Witten models, and whose morphisms are defects of all codimensions. By truncation, we obtain a (non-semisimple) 2-category $\mathcal{C}$ of bulk theories, surface defects, and isomorphism classes of line defects. Through a systematic application of the cobordism hypothesis we construct a unique extended oriented 2-dimensional TQFT valued in $\mathcal{C}$ for every affine Rozansky--Witten model. By evaluating this TQFT on closed surfaces we obtain the infinite-dimensional state spaces (graded by flavour and R-charges) of the initial 3-dimensional theory. Furthermore, we explicitly compute the commutative Frobenius algebras that classify the restrictions of the extended theories to circles and bordisms between them.
description: 50 pages; v2: some typos corrected
DrugEx v2 pretrained model (ChEMBL31)
Creators: name: Béquignon, Olivier J. M.
Publisher: name: Zenodo
Year: 2022
Subjects: deep learning
reinforcement learning
policy gradient
drug design
multi-objective optimization
exploration strategy
pretrained model
ChEMBL

description: This SMILES-model was built with version v2 of DrugEx. The dataset used to build this model was ChEMBL version 31.
Differences between real and particle-in-cell plasmas: effects of coarse-graining
Creators: name: Melzani, Mickaël
name: Walder, Rolf
name: Folini, Doris
name: Winisdoerffer, Christophe
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The PIC model relies on two building blocks. The first stems from the capability of computers to handle only up to $\sim10^{10}$ particles, while real plasmas contain from $10^4$ to $10^{20}$ particles per Debye sphere: a coarse-graining step must be used, whereby of the order of $p\sim10^{10}$ real particles are represented by a single computer superparticle. The second is field storage on a grid with its subsequent finite superparticle size. We introduce the notion of coarse-graining dependent quantities, i.e. physical quantities depending on the number $p$. They all derive from the plasma parameter $Λ$, which we show to be proportional to $1/p$. We explore three examples: the rapid collision- and fluctuation-induced thermalization of plasmas with different temperatures, that scale with the number of superparticles per grid cell and are a factor $p\sim10^{10}$ faster than in real plasmas; the high level of electrostatic fluctuations in a thermal plasma, with corrections due to the finite superparticle sizes; and the blurring of the linear spectrum of the filamentation instability, where the fastest growing modes do not dominate the total energy because of a high level of fluctuations. We stress that the enhanced collisions and correlations of PIC plasmas must be kept negligible toward kinetic physics.
description: 6 pages, proceedings of High Energy Processes in Relativistic Outflows (HEPRO04)
Self-guided tomography of time-frequency qudits
Creators: name: Serino, Laura
name: Rambach, Markus
name: Brecht, Benjamin
name: Romero, Jacquiline
name: Silberhorn, Christine
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: High-dimensional time-frequency encodings have the potential to significantly advance quantum information science; however, practical applications require precise knowledge of the encoded quantum states, which becomes increasingly challenging for larger Hilbert spaces. Self-guided tomography (SGT) has emerged as a practical and scalable technique for this purpose in the spatial domain. Here, we apply SGT to estimate time-frequency states using a multi-output quantum pulse gate. We achieve fidelities of more than 99\% for 3- and 5-dimensional states without the need for calibration or post-processing. We demonstrate the robustness of SGT against statistical and environmental noise, highlighting its efficacy in the photon-starved regime typical of quantum information applications.
title: An die Herren Mitglieder des Arbeitsausschusses. Die mit dem Schreiben vom 13. Dez. 1915 angekündigte Konferenz des Arbeitsausschusses fand planmäßig am 3. und 4. Januar ds. J. in Berlin statt. ...; [1916]
title: Münster i.W., im Januar 1916
titleType: Subtitle
Creators: name: (:Unav)
Publisher: name: Universitätsbibliothek der Ludwig-Maximilians-Universität München
Year: 2009

description: Konferenzprotokoll
The Confluent Heun functions in Black Hole Perturbation Theory: a spacetime interpretation
Creators: name: Minucci, Marica
name: Macedo, Rodrigo Panosso
Publisher: name: arXiv
Year: 2024
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: This work provides a spacetime interpretation of the confluent Heun functions within black hole perturbation theory (BHPT) and explores their relationship to the hyperboloidal framework. In BHPT, the confluent Heun functions are solutions to the radial Teukolsky equation, but they are traditionally studied without an explicit reference to the underlying spacetime geometry. Here, we show that the distinct behaviour of these functions near their singular points reflects the structure of key surfaces in black hole spacetimes. By interpreting homotopic transformations of the confluent Heun functions as changes in the spacetime foliation, we connect these solutions to different regions of the black hole's global structure, such as the past and future event horizons, past and future null infinity, spatial infinity, and even past and future timelike infinity. We also discuss the relationship between the confluent Heun functions and the hyperboloidal formulation of the Teukolsky equation. Although neither confluent Heun form of the radial Teukolsky equation can be interpreted as hyperboloidal slices, this approach offers new insights into wave propagation and scattering from a global black hole spacetime perspective.
description: 27 pages and 7 figures. Minor changes to match the version published in the topical collection 'Hyperboloidal Foliations in the Era of Gravitational-Wave Astronomy: From Mathematical Relativity to Astrophysics' in General Relativity and Gravitation
‘Footfalls echo in the memory’: displaced Durgas and migrant forms
Creators: name: Mukherji, Subha
Publisher: name: HUmanities Underground
Year: 2022
Subjects: migration and art

description: ‘Footfalls echo in the memory’: displaced Durgas and migrant forms Durga Puja is one of the biggest Hindu festivals of India, an annual event most widely and exuberantly celebrated in and around Kolkata. On display at the popular Barisha Club ‘pandal’ (pavilion for the installation of idols for religious festivals) in Kolkata through the second week of October was a Durga and her entourage: named ‘Bhaager Ma’, ‘the mother of divisions’ – or perhaps ‘the mother, parcelled out’. Durga the Mother Goddess is depicted as a disoriented, terrified refugee, sitting with her four children, clutching on to her last belongings, in the limbo of a detention centre marked by a cage located in a no-man’s land between the borders of India and Bangladesh. Behind her, a grey screen plays a video showing a muddy patch quivering with footprints hastily left by stealthy feet, big and small, as they fall at night. The footage is uncannily similar to the footfalls visible on YouTube since the BBC published its report of 12 October on Afghan refugees frantically fleeing the Taliban across the Iran-Turkey border, leaving marks on the rough ground as they ‘[sneaked] across’ in desperate hurry (Orla Guerin), while Turkey tightened controls.
DrugEx v2 pretrained model (Papyrus 05.5)
Creators: name: Schoenmaker, Linde
name: Béquignon, Olivier J. M.
Publisher: name: Zenodo
Year: 2022
Subjects: deep learning
reinforcement learning
policy gradient
drug design
multi-objective optimization
exploration strategy
pretrained model
Papyrus

description: This SMILES-model was built with version v2 of DrugEx. The dataset used to build this model was Papyrus version 05.5. This version of the model is adapted to be compatible with current DrugEx release 3.3.0.
DrugEx v2 pretrained model (Papyrus 05.5)
Creators: name: Schoenmaker, Linde
name: Béquignon, Olivier J. M.
Publisher: name: Zenodo
Year: 2022
Subjects: deep learning
reinforcement learning
policy gradient
drug design
multi-objective optimization
exploration strategy
pretrained model
Papyrus

description: This SMILES-model was built with version v2 of DrugEx. The dataset used to build this model was Papyrus version 05.5.
Supplementary materials for: CNN-based surrogate for the phase field damage mode
Creators: name: Gao, Yuxiang
name: Berger, Matthew
name: Duddu, Ravindra
Publisher: name: Zenodo
Year: 2022
Subjects: machine learning (ML)
Fracture mechanics
FEM
phase field fractue

description: We investigate the generalization of a CNN-based surrogate for the phase field model in predicting both damage and maximum/peak load, given the image of an arbitrary 2D microstructure of a unidirectional fiber-reinforced composite. We first discuss the phase field model and the numerical procedure to generate training and test data from synthetic microstructures with different volume fractions and fiber radii. We next present a two-stage approach for predicting peak load, achieved by first transforming a given fiber-encoded microstructure image to a continuous damage field; and second, predicting peak load from the damage field. A key finding is that the direct approach for predicting peak load from the microstructure image using a standard regression model fails to generalize. Instead, the damage field, even if imperfectly predicted, provides valuable cues for the CNN in generalizing across new microstructures. We describe several case studies to demonstrate the capability of the surrogate model to predict damage and peak load and to interpolate over fiber radii and volume fractions.
description: All .th files can be loaded by PyTorch commend torch.load("filename.th").Funding provided by: 3M
Crossref Funder Registry ID: http://dx.doi.org/10.13039/100004343
Award Number: Funding provided by: National Science Foundation
Crossref Funder Registry ID: http://dx.doi.org/10.13039/100000001
Award Number: PLR-1847173
description: The data in damage_prediction_X are predicted by our CNN-based Image-to-Image model given microstructure geometries. "geometry.th" is the geometry image of microstructure generated by our Python code with different volume fractions and fiber radii. "max_f.th" and "resampled_damage.th" are the peak load value and damage field calculated by FEniCS for corresponding microstructures.
Energy harvesting through gas dynamics in the free molecular flow regime between structured surfaces at different temperatures
Creators: name: Baier, Tobias
name: Dölger, Julia
name: Hardt, Steffen
Publisher: name: arXiv
Year: 2014
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: For a gas confined between surfaces held at different temperatures the velocity distribution shows a significant deviation from the Maxwell distribution when the mean free path of the molecules is comparable to or larger than the channel dimensions. If one of the surfaces is suitably structured, this non-equilibrium distribution can be exploited for momentum transfer in tangential direction between the two surfaces. This opens up the possibility to extract work from the system which operates as a heat engine. Since both surfaces are held at constant temperatures, the mode of momentum transfer is different from thermal creep flow that has gained more attention so far. This situation is studied in the limit of free-molecular flow for the case that an unstructured surface is allowed to move tangentially with respect to a structured surface. Parameter studies are conducted, and configurations with maximum thermodynamic efficiency are identified. Overall, it is shown that significant efficiencies can be obtained by tangential momentum transfer between structured surfaces.
Upper bounds on chromatic number of $\mathbb{E}^n$ in low dimensions
Creators: name: Arman, Andrii
name: Bondarenko, Andriy V.
name: Prymak, Andriy
name: Radchenko, Danylo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Combinatorics (math.CO)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics

description: Let $χ(\mathbb{E}^n)$ denote the chromatic number of the Euclidean space $\mathbb{E}^n$, i.e., the smallest number of colors that can be used to color $\mathbb{E}^n$ so that no two points unit distance apart are of the same color. We present explicit constructions of colorings of $\mathbb{E}^n$ based on sublattice coloring schemes that establish the following new bounds: $χ(\mathbb{E}^5)\le 140$, $χ(\mathbb{E}^n)\le 7^{n/2}$ for $n\in\{6,8,24\}$, $χ(\mathbb{E}^7)\le 1372$, $χ(\mathbb{E}^{9})\leq 17253$, and $χ(\mathbb{E}^n)\le 3^n$ for all $n\le 38$ and $n=48,49$.
description: 16 pages
Bilan d'étape du cluster 1 : actualités de IIIF360 et prémices de IIIF dans les archives
Creators: name: Robineau, Régis
name: Sajdak, Cécile
name: Stoll, Mathieu
name: Daugas, Mathilde
Publisher: name: Zenodo
Year: 2023
Subjects: biblissima
IIIF
archives
interopérabilité
franceArchives
IIIF360

description: Présentation du premier bilan des activités du cluster 1 de Biblissima+ lors des journées annuelles 2023 de Biblissima+ "Transmettre les textes anciens : défis et solutions numériques", au Campus Condorcet le 3 avril 2023.
Dynamic optimization of volatile fatty acids to enrich biohydrogen production using a deep learning neural network
Creators: name: Mahmoodi-Eshkaftaki, Mahmood
name: Mockaitis, Gustavo
name: Rafiee, Mohammad Rafie
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Biomolecules (q-bio.BM)
subject: FOS: Biological sciences
subject: I.6.0
subject: 92-10

description: A new strategy was developed to investigate the effect of volatile fatty acids (VFAs) on the efficiency of biogas production with a focus on improving bio-H$_2$. The inoculum used, anaerobic granular sludge obtained from a UASB reactor treating poultry slaughterhouse wastewater, was pretreated with five different pretreatments. The relationship between VFAs and biogas compounds was studied as time-dependent components. In time-dependent processes with small sample size data, regression models may not be good enough at estimating responses. Therefore, a deep learning neural network (DNN) model was developed to estimate the biogas compounds based on the VFAs. The accuracy of this model to predict the biogas compounds was higher than that of multivariate regression models. Further, it could predict the effect of time changes on biogas compounds. Analysis showed that all the pretreatments were able to increase the ratio of butyric acid / acetic acid successfully, decrease propionic acid drastically, and increase the efficiency of bio-H$_2$ production. As discovered, butyric acid had the greatest effect on bio-H$_2$, and propionic acid had the greatest effect on CH$_4$ production. The best amounts of the VFAs were determined using an optimization method, integrated DNN and desirability analysis, dynamically retrained based on digestion time. Accordingly, optimal ranges of acetic, propionic, and butyric acids were 823.2 - 1534.3, 36.3 - 47.4, and 1522 - 1822 mg/L, respectively, determined for digestion time of 25.23 - 123.63 h. These values resulted in the production of bio-H$_2$, N$_2$, CO$_2$, and CH$_4$ in ranges of 6.4 - 26.2, 12.2 - 43.2, 5 - 25.3, and 0 - 1.4 mmol/L, respectively. The optimum ranges of VFAs are relatively wide ranges and practically can be used in biogas plants.
CO2-rich protoplanetary discs as a probe of dust radial drift & trapping
Creators: name: Sellek, Andrew D.
name: Vlasblom, Marissa
name: van Dishoeck, Ewine F.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: MIR spectra imply considerable chemical diversity in the inner regions of protoplanetary discs: some are H2O-dominated, others by CO2. Sublimating ices from radially drifting dust grains are often invoked to explain some of this diversity, particularly the H2O-rich discs. We use a 1D protoplanetary disc evolution code to model how radially drifting dust grains that transport ices inwards to snowlines impact the chemistry of the inner regions of protoplanetary discs. We explore differences between smooth discs and those where radial drift is impeded by dust trapping outside gas gaps and quantify the effects of gap location and formation time. Discs evolve through an initial H2O-rich phase due to sublimating ices, followed by a CO2-rich phase as H2O vapour advects onto the star and CO2 advects into the inner disc from its snowline. The inclusion of traps hastens the transition between the phases, raising the CO2/H2O ratio; gaps opened early or close-in produce lower increases by blocking more CO2 ice from reaching the inner disc. This leads to a potential correlation between CO2/H2O and gap location that occurs on Myr timescales for fiducial parameters. We produce synthetic spectra from the models which we analyse with 0D LTE slab models to understand how this evolution may be expressed observationally. Whether the evolution can be retrieved depends on the contribution of dust grains to the optical depth: dust that couples to the gas after crossing the H2O snowline can add to the continuum optical depth and obscure the delivered H2O, largely hiding the evolution in its visible column density. However, the CO2/H2O visible column density ratio is only weakly sensitive to dust continuum obscuration. This suggests it may be a clearer tracer of the impact of transport on chemistry than individual column densities for spectra that show weak features probing deep enough in the disc. (Abridged)
description: Submitted 16 June 2024; Accepted 15 November 2024 for publication in A&A; Language Edited Version with correction to units in Fig 3
On edge-sets of bicliques in graphs
Creators: name: Groshaus, Marina
name: Hell, Pavol
name: Stacho, Juraj
Publisher: name: arXiv
Year: 2013
Subjects: subject: Combinatorics (math.CO)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: A biclique is a maximal induced complete bipartite subgraph of a graph. We investigate the intersection structure of edge-sets of bicliques in a graph. Specifically, we study the associated edge-biclique hypergraph whose hyperedges are precisely the edge-sets of all bicliques. We characterize graphs whose edge-biclique hypergraph is conformal (i.e., it is the clique hypergraph of its 2-section) by means of a single forbidden induced obstruction, the triangular prism. Using this result, we characterize graphs whose edge-biclique hypergraph is Helly and provide a polynomial time recognition algorithm. We further study a hereditary version of this property and show that it also admits polynomial time recognition, and, in fact, is characterized by a finite set of forbidden induced subgraphs. We conclude by describing some interesting properties of the 2-section graph of the edge-biclique hypergraph.
description: This version corrects an error in Theorem 11 found after the paper went into print
A Realistic Model under which the Genetic Code is Optimal
Creators: name: Buhrman, Harry
name: van der Gulik, Peter T. S.
name: Klau, Gunnar W.
name: Schaffner, Christian
name: Speijer, Dave
name: Stougie, Leen
Publisher: name: arXiv
Year: 2013
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: Genomics (q-bio.GN)
subject: FOS: Biological sciences

description: The genetic code has a high level of error robustness. Using values of hydrophobicity scales as a proxy for amino acid character, and the Mean Square measure as a function quantifying error robustness, a value can be obtained for a genetic code which reflects the error robustness of that code. By comparing this value with a distribution of values belonging to codes generated by random permutations of amino acid assignments, the level of error robustness of a genetic code can be quantified. We present a calculation in which the standard genetic code is shown to be optimal. We obtain this result by (1) using recently updated values of polar requirement as input; (2) fixing seven assignments (Ile, Trp, His, Phe, Tyr, Arg, and Leu) based on aptamer considerations; and (3) using known biosynthetic relations of the 20 amino acids. This last point is reflected in an approach of subdivision (restricting the random reallocation of assignments to amino acid subgroups, the set of 20 being divided in four such subgroups). The three approaches to explain robustness of the code (specific selection for robustness, amino acid-RNA interactions leading to assignments, or a slow growth process of assignment patterns) are reexamined in light of our findings. We offer a comprehensive hypothesis, stressing the importance of biosynthetic relations, with the code evolving from an early stage with just glycine and alanine, via intermediate stages, towards 64 codons carrying todays meaning.
description: 22 pages, 3 figures, 4 tables Journal of Molecular Evolution, July 2013
Signatures of Rapidly Rotating Stars with Chemically Homogeneous Evolution in the First Galaxies
Creators: name: Liu, Boyuan
name: Sibony, Yves
name: Meynet, Georges
name: Bromm, Volker
Publisher: name: arXiv
Year: 2024
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The James Webb Space Telescope (JWST) has revealed an unexpectedly high abundance of UV luminous galaxies at redshifts $z\gtrsim 10$, challenging `standard' galaxy formation models. This study investigates the role of rapidly rotating (massive) stars undergoing chemically homogeneous evolution (CHE) in reconciling this potential tension. These stars are more compact, hotter, and exhibit enhanced UV emission. We find that the rest-frame UV luminosity of star-forming galaxies can be significantly enhanced by a factor of $\sim 3-6$ when CHE stars above a minimum initial mass of $m_{\star,\min}^{\rm CHE}\sim 2-10\ \rm M_\odot$ account for more than half of the total stellar mass following a Salpeter initial mass function. As a result, the UV luminosity functions observed at $z\sim 12-16$ can be reproduced with less extreme values of star formation efficiency and UV luminosity stochastic variability. Our results highlight the potential of CHE in explaining the UV-bright galaxy populations detected by JWST and call for future work to explore the broader astrophysical implications of CHE and its associated phenomena in the early universe, such as gamma-ray bursts, compact object binaries, and metal enrichment.
description: 8+4 pages, 7 figures, accepted for publication in ApJL, see Figs. 2 and 3 for main results
Martin Mulsow, Radikale Frühaufklärung in Deutschland 1680–1720. Bd. 1: Moderne aus dem Untergrund. Bd. 2: Clandestine Vernunft. Göttingen, Wallstein 2018
Creators: name: Laube, Stefan
Publisher: name: Humboldt-Universität zu Berlin
Year: 2019
Subjects: subject: 193 Philosophie Deutschlands und Österreich

description: Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Striglina whalleyi Chen & Zhang & Wang 2024, sp. nov.
Creators: name: Chen, Feiran
name: Zhang, Yulong
name: Wang, Min
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Thyrididae
Striglina
Striglina whalleyi

description: Striglina whalleyi sp. nov.
Materials
Type status: Holotype. Occurrence: recordedBy: Hai-Ming Xu; sex: male; occurrenceID: 65C1AE97-57B7-50AD-8DEA-5D4DC03F3E10; Location: country: China; stateProvince: Yunnan; county: Chuxiong; locality: Yipinglang; Event: eventDate: 10 Apr 2013
Type status: Paratype. Occurrence: recordedBy: Hai-Ming Xu; sex: 2 males; occurrenceID: 34006CB0-52AE-5EA6-A1AD-BCAD2408B30E; Location: country: China; stateProvince: Guangdong; county: Shaoguan; locality: Nanling; Event: eventDate: 05 Jun 2011
Description
Male (Fig. 1 a). Wingspan 23-25 mm. Antennae filiform, brown; head dark brown; thorax, tegulae and legs brownish-yellow; abdomen dorsally brown. Fore-wing ground colour brownish-yellow with dark brown posterior line from near apex to middle of inner margin, near the discal cell with two large dark puncta; cilia whitish-yellow, terminally black. Hind-wing ground colour brownish-yellow, median line indistinct at costa.
Male genitalia (Fig. 3 a). Uncus bifid apically, with two shorter processes; two lateral processes apically curved inwards. Subscaphium hairy. Gnathos strip-type with serried tooth. The valvae weak membranous straps; median valval process weak. Sacculus process short sclerotised, enlarged apically. Aedeagus short and broad with a cluster of cornuti.
Female: unknown.
Diagnosis
This new species resembles S. irresecta obscura Whalley, 1976, but the ground colour of wings is yellow (reddish-brown in the latter, Fig. 1 a, b), the oblique line from apex to middle of dorsum is straight, dark brown (ochre in the latter). In male genitalia, the uncus is broader, the sacculus process is shorter than S. irresecta obscura, the aedeagus is broader basal (Fig. 3 a, b).
Etymology
The species is dedicated to Mr. Paul Ernest Sutton Whalley, in honour of his marvellous work on Thyrididae.
Distribution
China: Yunnan (Chuxiong), Guangdong (Shaoguan).
Notes
Our study shows that S. irresecta obscura seems more closely related to the new species than to S. irresecta irresecta morphologically and zoogeographically. Judging from the holotype pictures (Fig. 2) from the Natural History Museum (2014), the hind-wing pattern of S. irresecta is also showing the same characteristics.
description: Published as part of Chen, Feiran, Zhang, Yulong & Wang, Min, 2024, Two new species of Striglina Guenée, 1877 (Lepidoptera, Thyrididae) from China, pp. e 126268 in Biodiversity Data Journal 12 on page e126268, DOI: 10.3897/BDJ.12.e126268
Modelling the asymmetric wind of the luminous blue variable binary MWC 314
Creators: name: Lobel, A.
name: Groh, J. H.
name: Martayan, C.
name: Frémat, Y.
name: Dozinel, K. Torres
name: Raskin, G.
name: Van Winckel, H.
name: Prins, S.
name: Pessemier, W.
name: Waelkens, C.
name: Hensberge, H.
name: Dummortier, L.
name: Jorissen, A.
name: Van Eck, S.
name: Lehmann, H.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present a spectroscopic analysis of MWC 314, a luminous blue variable (LBV) candidate with an extended bipolar nebula. The detailed spectroscopic variability is investigated to determine if MWC 314 is a massive binary system with a supersonically accelerating wind or a low-mass B[e] star. We compare the spectrum and spectral energy distribution to other LBVs (such as P Cyg) and find very similar physical wind properties, indicating strong kinship. We combined long-term high-resolution optical spectroscopic monitoring and V-band photometric observations to determine the orbital elements and stellar parameters and to investigate the spectral variability with the orbital phases. We developed an advanced model of the large-scale wind-velocity and wind-density structure with 3-D radiative transfer calculations that fit the orbitally modulated P Cyg profile of He I lam5876, showing outflow velocities above 1000 km/s. We find that MWC 314 is a massive semi-detached binary system of ~1.22 AU, observed at an inclination angle of i=72.8 deg. with an orbital period of 60.8 d and e=0.23. The primary star is a low-vsini LBV candidate of m1=39.6 Msun and R1=86.8 Rsun. The detailed radiative transfer fits show that the geometry of wind density is asymmetric around the primary star with increased wind density by a factor of 3.3, which leads the orbit of the primary. The variable orientation causes the orbital modulation that is observed in absorption portions of P Cyg wind lines. Wind accretion in the system produces a circumbinary disc. MWC 314 is in a crucial evolutionary phase of close binary systems, when the massive primary star has its H envelope being stripped and is losing mass to a circumbinary disc. MWC 314 is a key system for studying the evolutionary consequences of these effects.
description: 14 pages, 25 figures, 4 tables, Accepted for Astronomy and Astrophysics
One-way transparent sheets
Creators: name: Ra'di, Younes
name: Asadchy, Viktar
name: Tretyakov, Sergei
Publisher: name: arXiv
Year: 2013
Subjects: subject: Optics (physics.optics)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: In this paper we introduce the concept of metasurfaces which are fully transparent when looking from one of the two sides of the sheet and have controllable functionalities for waves hitting the opposite side (one-way transparent sheets). We address the question on what functionalities are allowed, considering limitations due to reciprocity and passivity. In particular, we have found that it is possible to realize one-way transparent sheets which have the properties of a twist-polarizer in reflection or transmission when illuminated from the other side. Also one-way transparent sheets with controllable co-polarized reflection and transmission from the opposite side are feasible. We show that particular non-reciprocal magneto-electric coupling inside the sheet is necessary to realize lossless non-active transparent sheets. Furthermore, we derive the required polarizabilities of constituent dipole particles such that the layers composed of them form one-way transparent sheets. We conclude with design and simulations of an example of a nonreciprocal one-way transparent sheet functioning as an isolating twist-polarizer.
description: 8 pages, 4 figures
ALMA-IMF XVI: Mass-averaged temperature of cores and protostellar luminosities in the ALMA-IMF protoclusters
Creators: name: Motte, F.
name: Pouteau, Y.
name: Nony, T.
name: Dell'Ova, P.
name: Gusdorf, A.
name: Brouillet, N.
name: Stutz, A. M.
name: Bontemps, S.
name: Ginsburg, A.
name: Csengeri, T.
name: Men'shchikov, A.
name: Valeille-Manet, M.
name: Louvet, F.
name: Bonfand, M.
name: Galván-Madrid, R.
name: Álvarez-Gutiérrez, R. H.
name: Armante, M.
name: Bronfman, L.
name: Chen, H. -R. V.
name: Cunningham, N.
name: Díaz-González, D.
name: Didelon, P.
name: Fernández-López, M.
name: Herpin, F.
name: Kessler, N.
name: Koley, A.
name: Lefloch, B.
name: Nestour, N. Le
name: Liu, H. -L.
name: Moraux, E.
name: Luong, Q. Nguyen
name: Olguin, F.
name: Salinas, J.
name: Sandoval-Garrido, N. A.
name: Sanhueza, P.
name: Veyry, R.
name: Yoo, T.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: ALMA-IMF imaged 15 massive protoclusters down to a resolution of of 2 kau scales, identifying about 1000 star-forming cores. The mass and luminosity of these cores, which are fundamental physical characteristics, are difficult to determine, a problem greatly exacerbated at the distances >2 kpc of ALMA-IMF protoclusters. We combined new datasets and radiative transfer modeling to characterize these cores. We estimated their mass-averaged temperature and the masses these estimates imply. For 1/6 of the sample, we measured the bolometric luminosities, implementing deblending corrections when necessary. We used spectral energy distribution (SED) analysis obtained with the PPMAP Bayesian procedure, which aims to preserve the best angular resolution of the input data. We extrapolated the luminosity and dust temperature images provided by PPMAP at 2.5" resolution to estimate those of individual cores, which were identified at higher angular resolution. To do this, we applied approximate radiative transfer relationships between the luminosity of a protostar and the temperature of its surrounding envelope and between the external heating of prestellar cores and their temperatures. For the first time, we provide data-informed estimates of dust temperatures for 883 cores identified with ALMA-IMF: 17-31 K and 28-79 K (5th and 95th percentiles, up to 127 K) for the 617 prestellar and 266 protostellar cores, respectively. We also measured protostellar luminosities spanning 20-80 000 Lsun. For hot cores, we estimated systematically lower temperatures than studies based on complex organic molecules. We established a mass-luminosity evolutionary diagram, for the first time at the core spatial resolution and for a large sample of high-mass protostellar cores. The ALMA-IMF data favor a scenario in which protostars accrete their mass from a larger mass reservoir than their host cores.
description: 42 pages, 13 figures, accepted by A&A
The disappearance of a narrow Mg II absorption system in quasar SDSS J165501.31+260517.4
Creators: name: Chen, Zhi-Fu
name: Qin, Yi-Ping
name: Gu, Min-Feng
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: In this letter, we present for the first time, the discovery of the disappearance of a narrow Mg II $λ\lambda2796,2803$ absorption system from the spectra of quasar SDSS J165501.31+260517.4 ($z_{\rm e}=1.8671$). This absorber is located at $z_{\rm abs} =1.7877$, and has a velocity offset of $8,423\rm ~km~s^{-1}$ with respect to the quasar. According to the velocity offset and the line variability, this narrow Mg II $λ\lambda2796,2803$ absorption system is likely intrinsic to the quasar. Since the corresponding UV continuum emission and the absorption lines of another narrow Mg II $λ\lambda2796,2803$ absorption system at $z_{\rm abs}=1.8656$ are very stable, we think that the disappearance of the absorption system is unlikely to be caused by the change in ionization of absorption gas. Instead, it likely arises from the motion of the absorption gas across the line of sight.
Dynamics and Afterglow Light Curves of GRB Blast Waves Encountering a Density Bump or Void
Creators: name: Uhm, Z. Lucas
name: Zhang, Bing
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We investigate the dynamics and afterglow light curves of gamma-ray burst (GRB) blast waves that encounter various density structures (such as bumps, voids, or steps) in the surrounding ambient medium. We present and explain the characteristic response features that each type of density structures in the medium leaves on the forward shock (FS) and reverse shock (RS) dynamics, for blast waves with either a long-lived or short-lived RS. We show that, when the ambient medium density drops, the blast waves exhibit in some cases a period of an actual acceleration (even during their deceleration stage), due to adiabatic cooling of blast waves. Comparing numerical examples that have different shapes of bumps or voids, we propose a number of consistency tests that correct modeling of blast waves needs to satisfy. Our model results successfully pass these tests. Employing a Lagrangian description of blast waves, we perform a sophisticated calculation of afterglow emission. We show that, as a response to density structures in the ambient medium, the RS light curves produce more significant variations than the FS light curves. Some observed features (such as re-brightenings, dips, or slow wiggles) can be more easily explained within the RS model. We also discuss on the origin of these different features imprinted on the FS and RS light curves.
description: Accepted for publication in ApJ, 33 pages, 17 figures