cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Astraeus V: The emergence and evolution of metallicity scaling relations during the Epoch of Reionization
Creators: name: Ucci, Graziano
name: Dayal, Pratika
name: Hutter, Anne
name: Kobayashi, Chiaki
name: Gottloeber, Stefan
name: Yepes, Gustavo
name: Hunt, Leslie
name: Legrand, Laurent
name: Tortora, Crescenzo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In this work, we have implemented a detailed physical model of galaxy chemical enrichment into the ${\it Astraeus}$ (semi-numerical rAdiative tranSfer coupling of galaxy formaTion and Reionization in N-body dark matter simUlationS) framework which couples galaxy formation and reionization in the first billion years. Simulating galaxies spanning over 2.5 orders of magnitude in halo mass with $M_h \sim 10^{8.9-11.5} M_\odot$ ($M_h \sim 10^{8.9-12.8} M_\odot$) at $z \sim 10 ~ (5)$, we find: (i) smooth-accretion of metal-poor gas from the intergalactic medium (IGM) plays a key role in diluting the interstellar medium (ISM) metallicity which is effectively restored due to self-enrichment from star formation; (ii) a redshift averaged gas-mass loading factor that depends on the stellar mass as $η_g \approx 1.38 ({M_*}/{10^{10} M_\odot})^{-0.43}$; (iii) the mass-metallicity relation is already in place at $z \sim 10$ and shows effectively no redshift evolution down to $z \sim 5$; (iv) for a given stellar mass, the metallicity decreases with an increase in the star formation rate (SFR); (v) the key properties of the gas-phase metallicity (in units of 12+log(O/H), stellar mass, SFR and redshift are linked through a high-redshift fundamental plane of metallicity (HFPZ) for which we provide a functional form; (vi) the mass-metallicity-SFR relations are effectively independent of the reionization radiative feedback model for $M_* \geq 10^{6.5} M_\odot$ galaxies; (vii) while low-mass galaxies ($M_h \leq 10^9 M_\odot$) are the key contributors to the metal budget of the IGM at early times, higher mass halos provide about 50% of the metal budget at lower-redshifts.
description: Accepted to MNRAS
Kräfte am Schiffsrumpf beim Manövrieren in flachem Wasser
Creators: name: Zhao, Yuanxie
Publisher: name: TUHH Universitätsbibliothek
Year: 1984
Subjects: classificationCode: 52.00
subject: Maschinenbau, Energietechnik, Fertigungstechnik: Allgemeines
subject: Schiffsrumpf
subject: Manöver

description: Kräfte am Schiffsrumpf beim Manövrieren in flachem Wasser
Adolf Hoffmann, Das Gartenstadtion in der Villa Hadriana
Creators: name: Lauter, Hans
Publisher: name: Bonner Jahrbücher
Year: 2020

description: Rezension zu: Adolf Hoffmann, Das Gartenstadtion in der Villa Hadriana. Deutsches Archäologisches Institut Rom, Sonderschriften Band 4. Verlag Philipp von Zabern, Mainz 1980. 87 Seiten, 60 Tafeln, 37 Beilagen.
description: Bonner Jahrbücher, Bd. 182.1982: Bonner Jahrbücher
Red and dead: The progenitor of SN 2012aw in M95
Creators: name: Fraser, M.
name: Maund, J. R.
name: Smartt, S. J.
name: Botticella, M. -T.
name: Dall'Ora, M.
name: Inserra, C.
name: Tomasella, L.
name: Benetti, S.
name: Ciroi, S.
name: Eldridge, J. J.
name: Ergon, M.
name: Kotak, R.
name: Mattila, S.
name: Ochner, P.
name: Pastorello, A.
name: Reilly, E.
name: Sollerman, J.
name: Stephens, A.
name: Taddia, F.
name: Valenti, S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Core-collapse supernovae (SNe) are the spectacular finale to massive stellar evolution. In this Letter, we identify a progenitor for the nearby core-collapse SN 2012aw in both ground based near-infrared, and space based optical pre-explosion imaging. The SN itself appears to be a normal Type II Plateau event, reaching a bolometric luminosity of 10$^{42}$ erg s$^{-1}$ and photospheric velocities of $\sim$11,000 \kms\ from the position of the H$β$ P-Cygni minimum in the early SN spectra. We use an adaptive optics image to show that the SN is coincident to within 27 mas with a faint, red source in pre-explosion HST+WFPC2, VLT+ISAAC and NTT+SOFI images. The source has magnitudes $F555W$=26.70$\pm$0.06, $F814W$=23.39$\pm$0.02, $J$=21.1$\pm$0.2, $K$=19.1$\pm$0.4, which when compared to a grid of stellar models best matches a red supergiant. Interestingly, the spectral energy distribution of the progenitor also implies an extinction of $A_V>$1.2 mag, whereas the SN itself does not appear to be significantly extinguished. We interpret this as evidence for the destruction of dust in the SN explosion. The progenitor candidate has a luminosity between 5.0 and 5.6 log L/\lsun, corresponding to a ZAMS mass between 14 and 26 \msun\ (depending on $A_V$), which would make this one of the most massive progenitors found for a core-collapse SN to date.
description: Submitted to ApJ Letters
A systematic study of super-Eddington layers in the envelopes of massive stars
Creators: name: Agrawal, Poojan
name: Stevenson, Simon
name: Szécsi, Dorottya
name: Hurley, Jarrod
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The proximity to the Eddington luminosity has been attributed as the cause of several observed effects in massive stars. Computationally, if the luminosity carried through radiation exceeds the local Eddington luminosity in the low-density envelopes of massive stars, it can result in numerical difficulties, inhibiting further computation of stellar models. This problem is exacerbated by the fact that very few massive stars are observed beyond the Humphreys-Davidson limit, the same region in the Hertzsprung-Russell diagram where the aforementioned numerical issues relating to the Eddington luminosity occur in stellar models. One-dimensional stellar evolution codes have to use pragmatic solutions to evolve massive stars through this computationally difficult phase. In this work, we quantify the impact of these solutions on the evolutionary properties of massive stars. We used the stellar evolution code MESA with commonly used input parameters for massive stellar models to compute the evolution of stars in the initial mass range of 10-110 M$_\odot$ at one-tenth of solar metallicity. We find that numerical difficulties in stellar models with initial masses greater than or equal to 30 M$_\odot$ cause these models to fail before the end of core helium burning. Recomputing these models using the same physical inputs but three different pragmatic solutions to treat the numerical instability, we find that the maximum radial expansion achieved by stars can vary by up to 2000 R$_\odot$, while the remnant mass of the stars can vary by up to 14 M$_\odot$ between the sets. These differences can have implications on studies such as binary population synthesis.
description: Revised version; Accepted for publication in A&A
Joachim Werner (Hrsg.), Die Ausgrabungen in St. Ulrich und Afra in Augsburg 1961-1968
Creators: name: Fehring, Günter P.
Publisher: name: Bonner Jahrbücher
Year: 2020

description: Rezension zu: Joachim Werner (Hrsg.), Die Ausgrabungen in St. Ulrich und Afra in Augsburg 1961-1968. Mit Beiträgen von A. Radnoti (f), W. Haas, W. Volkert, J. Werner, A. France-Lanord, W. Ruckdeschel, G. Ziegelmayer, H. U. Nuber, B. Bischoff, H. Fillitz, M. Weidemann, F. Prinz, G. Pohl, I. Fingerlin. Veröffentlichungen der Kommission zur archäologischen Erforschung des spätrömischen Raetien der bayerischen Akademie der Wissenschaften. Münchner Beiträge zur Vor- und Frühgeschichte 23. C. H. Beck’sche Verlagsbuchhandlung, München 1977. Textband XVIII und 584 Seiten mit 137 Abbildungen und 19 Tabellen; Tafelband mit 204 Schwarzweißtafeln, 1 Farbtafel und 2 Beilagen.
description: Bonner Jahrbücher, Bd. 182.1982: Bonner Jahrbücher
Angular-dependent Klein tunneling in photonic graphene
Creators: name: Zhang, Zhaoyang
name: Feng, Yuan
name: Li, Feng
name: Koniakhin, Sergei
name: Li, Changbiao
name: Liu, Fu
name: Zhang, Yanpeng
name: Xiao, Min
name: Malpuech, Guillaume
name: Solnyshkov, Dmitry
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The Klein paradox consists in the perfect tunneling of relativistic particles through high potential barriers. As a curious feature of particle physics, it is responsible for the exceptional conductive properties of graphene. It was recently studied in the context of atomic condensates and topological photonics and phononics. While in theory the perfect tunneling holds only for normal incidence, so far the angular dependence of the Klein tunneling and its strong variation with the barrier height were not measured experimentally. In this work, we capitalize on the versatility of atomic vapor cells with paraxial beam propagation and index patterning by electromagnetically-induced transparency. We report the first experimental observation of perfect Klein transmission in a 2D photonic system (photonic graphene) at normal incidence and measure the angular dependence. Counter-intuitively, but in agreement with the Dirac equation, we observe that the decay of the Klein transmission versus angle is suppressed by increasing the barrier height, a key result for the conductivity of graphene and its analogues.
Peter Ilisch, Münzefunde und Geldumlauf in Westfalen in Mittelalter und Neuzeit
Creators: name: Schneider, Konrad
Publisher: name: Bonner Jahrbücher
Year: 2020

description: Rezension zu: Peter Ilisch, Münzefunde und Geldumlauf in Westfalen in Mittelalter und Neuzeit. Veröffentlichungen des Provinzialinstituts für Westfälische Landes- und Volksforschung des Landschaftsverbandesb Westfalen-Lippe Reihe 1, Heft 23. Aschendorff Verlag, Münster 1980. 266 Seiten, 4 Karten.
description: Bonner Jahrbücher, Bd. 182.1982: Bonner Jahrbücher
Leo S. Klejn, Archaeological Typology
Creators: name: Eggert, Manfred K. H.
Publisher: name: Bonner Jahrbücher
Year: 2020

description: Rezension zu: Leo S. Klejn, Archaeological Typology. Translated from the Russian by Penelope Dole. British Archaeological Reports, International Series S 153, Oxford 1982. 321 Seiten und 25 Abbildungen.
description: Bonner Jahrbücher, Bd. 185.1985: Bonner Jahrbücher
Constraining scalarization in scalar-Gauss-Bonnet gravity through binary pulsars
Creators: name: Danchev, Victor I.
name: Doneva, Daniela D.
name: Yazadjiev, Stoytcho S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In the present paper we derive strong constrains on scalarization in scalar-Gauss-Bonnet (sGB) gravity using observations of pulsars in close binary systems. Since scalarized neutron stars carry a nonzero scalar change, they emit scalar dipole radiation while inspiraling which speeds up the orbital decay. The observations support the conjecture that such radiation is either absent or very small for the observed binary pulsars. Using this, we determine the allowed range of parameters for sGB gravity. We also transfer the derived constraints to black holes in sGB gravity. It turns out that the maximum mass of a scalarized static black hole can not exceed roughly ten to twenty solar masses, depending on the initial assumptions we make for the nuclear matter equations of state. The black hole scalar charge on the other hand can reach relatively large values that are potentially observable.
description: 17 pages, 6 figures v2: Improvements made, additional references added, v3: Improvements of data analysis methods and text, v4: Improvements of data analysis, matches the published version
Top forward-backward asymmetry in chiral U(1)' models
Creators: name: Ko, P.
name: Omura, Yuji
name: Yu, Chaehyun
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We construct flavor-dependent chiral U(1)' models with a Z' boson which couples to the right-handed up-type quarks in the standard model (SM). To make the models have realistic renormalizable Yukawa couplings, we introduce new Higgs doublets with nonzero U(1)' charges. Anomaly-free condition can be satisfied by adding extra chiral fermions. We show that these models could analyze the discrepancy between the SM prediction and empirical data in the top forward-backward asymmetry at the Tevatron.
description: 4 pages, 2 figures, Submitted to proceedings of TOP2011 - 4th International Workshop on Top Quark Physics, 25-30th September 2011, Sant Feliu de Guixols, Spain
Günter Grimm, Heinz Heinen und Erich Winter (Hrsg.), Alexandrien. Kulturbegegnungen dreier Jahrtausende im Schmelztiegel einer mediterranen Großstadt
Creators: name: Wirth, Gerhard
Publisher: name: Bonner Jahrbücher
Year: 2020

description: Rezension zu: Günter Grimm, Heinz Heinen und Erich Winter (Hrsg.), Alexandrien. Kulturbegegnungen dreier Jahrtausende im Schmelztiegel einer mediterranen Großstadt. Herausgegeben unter Mitarbeit von Norbert Hinske. Verlag Philipp von Zabern, Mainz 1981. VIII und 76 Seiten, 22 Tafeln.
description: Bonner Jahrbücher, Bd. 185.1985: Bonner Jahrbücher
On Stability Problems of Omega and 3-Disjoint Paths Omega Multi-stage Interconnection Networks
Creators: name: Rastogi, Ravi
name: Nitin
name: Chauhan, Durg Singh
name: Govil, Mahesh Chandra
Publisher: name: arXiv
Year: 2012
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: The research paper emphasizes that the Stable Matching problems are the same as the problems of stable configurations of Multi-stage Interconnection Networks (MIN). We have discusses the Stability Problems of Existing Regular Omega Multi-stage Interconnection Network (OMIN) and Proposed 3-Disjoint Paths Omega Multi-stage Interconnection Network (3DON) using the approaches and solutions provided by the Stable Matching Problem. Specifically, Stable Marriage Problem is used as an example of Stable Matching. On application of the concept of the Stable Marriage over the MINs states that OMIN is highly stable in comparison to 3DON.
Casimir Energy of the Universe and the Dark Energy Problem
Creators: name: Ichinose, Shoichi
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We regard the Casimir energy of the universe as the main contribution to the cosmological constant. Using 5 dimensional models of the universe, the flat model and the warped one, we calculate Casimir energy. Introducing the new regularization, called {\it sphere lattice regularization}, we solve the divergence problem. The regularization utilizes the closed-string configuration. We consider 4 different approaches: 1) restriction of the integral region (Randall-Schwartz), 2) method of 1) using the minimal area surfaces, 3) introducing the weight function, 4) {\it generalized path-integral}. We claim the 5 dimensional field theories are quantized properly and all divergences are renormalized. At present, it is explicitly demonstrated in the numerical way, not in the analytical way. The renormalization-group function ($\be$-function) is explicitly obtained. The renormalization-group flow of the cosmological constant is concretely obtained.
description: 12 pages, 13 figures, Proceedings of DSU2011(2011.9.26-30,Beijin)
Particle-wave duality in quantum tunneling of a bright soliton
Creators: name: Wang, Ching-Hao
name: Hong, Tzay-Ming
name: Lee, Ray-Kuang
name: Wang, Daw-Wei
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: One of the most fundamental difference between classical and quantum mechanics is observed in the particle tunneling through a localized potential: the former predicts a discontinuous transmission coefficient ($T$) as a function in incident velocity between one (complete penetration) and zero (complete reflection), while the later always changes smoothly as a wave nature. Here we report a systematic study of the quantum tunneling property for a bright soliton in ultracold atoms, which behaves as a classical particle (matter wave) in the limit of small (large) incident velocity. In the intermediate regime, the classical and quantum properties are combined via a finite (but not full) discontinuity in the tunneling transmission coefficient. We demonstrate that the formation of a localized bound state is essential to describe such inelastic collisions, showing a nontrivial nonlinear effect on the quantum transportation of a bright soliton.
description: 4 pages with 2 figures
New Post-AGB star models as tools to understand AGB evolution and nucleosynthesis
Creators: name: Kamath, Devika
name: Dell'Agli, Flavia
name: Ventura, Paolo
name: Van Winckel, Hans
name: Karakas, Amanda
name: Tosi, Silvia
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We study a sample of post-AGB stars in the Galaxy, with known surface chemical composition and s-process enrichment. The recent determination of the luminosities of these sources, based on Gaia parallaxes, allows for the fist time a deep investigation of Galactic post-AGB stars, with the possibility of characterising the individual objects in terms of mass, chemical composition and age of the progenitors. To this aim we used available evolutionary sequences of AGB stars, extended to the post-AGB phase, complemented by new models, specifically calculated for the present study. The combined knowledge of the surface carbon and of the luminosity proves the most valuable indicator of the previous history of the star, particularly for what regards the efficiency of the various mechanisms able to alter the surface chemical composition and the growth of the core mass. This kind of analysis allows dissecting different classes of stars, such as low-mass objects, that evolved as M-type stars for the whole AGB lifetime, carbon stars, massive AGB stars that experienced hot bottom burning. The potentialities of this approach to shed new light on still debated issues related to the AGB evolution are also commented.
description: to be submitted to MNRAS. 19 pages, 9 figures
The Great Escape: How Exoplanets and Smaller Bodies Desert Dying Stars
Creators: name: Veras, Dimitri
name: Wyatt, Mark C.
name: Mustill, Alexander J.
name: Bonsor, Amy
name: Eldridge, John J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: Mounting discoveries of extrasolar planets orbiting post-main sequence stars motivate studies aimed at understanding the fate of these planets. In the traditional "adiabatic" approximation, a secondary's eccentricity remains constant during stellar mass loss. Here, we remove this approximation, investigate the full two-body point-mass problem with isotropic mass loss, and illustrate the resulting dynamical evolution. The magnitude and duration of a star's mass loss combined with a secondary's initial orbital characteristics might provoke ejection, modest eccentricity pumping, or even circularisation of the orbit. We conclude that Oort clouds and wide-separation planets may be dynamically ejected from 1-7 Solar-mass parent stars during AGB evolution. The vast majority of planetary material which survives a supernova from a 7-20 Solar-mass progenitor will be dynamically ejected from the system, placing limits on the existence of first-generation pulsar planets. Planets around >20 Solar-mass black hole progenitors may easily survive or readily be ejected depending on the core collapse and superwind models applied. Material ejected during stellar evolution might contribute significantly to the free-floating planetary population.
description: 23 pages, 16 figures, accepted for publication in MNRAS
Symmetryless Dark Matter
Creators: name: Kajiyama, Yuji
name: Kannike, Kristjan
name: Raidal, Martti
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: It is appealing to stabilize dark matter by the same discrete symmetry that is used to explain the structure of quark and lepton mass matrices. However, to generate the observed fermion mixing patterns, any flavor symmetry must necessarily be broken, rendering dark matter unstable. We study singlet, doublet and triplet SU(2) multiplets of both scalar and fermion dark matter candidates and enumerate the conditions under which no d < 6 dark matter decay operators are generated even in the case if the flavor symmetry is broken to nothing. We show that the VEVs of flavon scalars transforming as higher multiplets (e.g. triplets) of the flavor group must be at the electroweak scale. The most economical way for that is to use SM Higgs boson(s) as flavons. Such models can be tested by the LHC experiments. This scenario requires the existence of additional Froggatt-Nielsen scalars that generate hierarchies in Yukawa couplings. We study the conditions under which large and small flavor breaking parameters can coexist without destabilizing the dark matter.
description: 8 pages, no figures
Accelerating BAO Scale Fitting Using Taylor Series
Creators: name: Hansen, Matthew
name: Krolewski, Alex
name: Slepian, Zachary
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The Universe is currently undergoing accelerated expansion driven by dark energy. Dark energy's essential nature remains mysterious: one means of revealing it is by measuring the Universe's size at different redshifts. This may be done using the Baryon Acoustic Oscillation (BAO) feature, a standard ruler in the galaxy 2-Point Correlation Function (2PCF). In order to measure the distance scale, one dilates and contracts a template for the 2PCF in a fiducial cosmology, using a scaling factor $α$. The standard method for finding the best-fit $α$ is to compute the likelihood over a grid of roughly 100 values of it. This approach is slow; in this work, we propose a significantly faster way. Our method writes the 2PCF as a polynomial in $α$ by Taylor-expanding it about $α= 1$, exploiting that we know the fiducial cosmology sufficiently well that $α$ is within a few percent of unity. The likelihood resulting from this expansion may then be analytically solved for the best-fit $α$. Our method is 48-85$\times$ faster than a directly comparable approach in which we numerically minimize $α$, and $\sim$$12,000 \times$ faster than the standard iterative method. Our work will be highly enabling for upcoming large-scale structure redshift surveys such as that by Dark Energy Spectroscopic Instrument (DESI).
description: 13 pages, 6 figures, accepted MNRAS
Accretion-powered chromospheres in classical T Tauri stars
Creators: name: Petrov, P. P.
name: Gahm, G. F.
name: Stempels, H. C.
name: Walter, F. M.
name: Artemenko, S. A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: (Abridged) Optical spectra of classical T Tauri stars (cTTS) are rich in emission lines of low-excitation species that are composed of narrow and broad components, related to two regions with different kinematics, densities, and temperatures. The photospheric spectrum is often veiled by an excess continuous emission. This veiling is usually attributed to radiation from a heated region beneath the accretion shock. The aim of this research is to clarify the nature of the veiling, and whether the narrow chromospheric lines of Fe I and other metals represent a standard chromosphere of a late-type star, or are induced by mass accretion. From high-resolution spectroscopy of DR Tauri we found that the amount of veiling in this star varies from practically nothing to factors more than 10 times the stellar continuum intensity, and that the veiling is caused by both a non-photospheric continuum and chromospheric line emission filling in the photospheric absorption lines. This effect can be shown to exist in several other T Tauri stars. We conclude that enhanced chromospheric emission in cTTS is linked not only to solar-like magnetic activity, but is powered to a greater extent by the accreting gas. We suggest that the area of enhanced chromospheric emission is induced by mass accretion, which modifies the local structure of stellar atmosphere in an area that is more extended than the hot accretion spot. The narrow emission lines from this extended area are responsible for the extra component in the veiling through line-filling of photospheric absorption lines.
description: 11 pages, 13 figures
Such stuff as dreams are made on: a finite element tale of optimal transport and brain clearance
Creators: name: Rognes, Marie E
Publisher: name: Zenodo
Year: 2022
Subjects: brain, optimal transport, dolfin-adjoint, finite element methods

description: Plenary lecture at the Acta Numerica's 30th Birthday Conference, Banach Centre at Bedlewo, Poland, June 2022
Terahertz Radiation from the Dyakonov-Shur Instability of Hydrodynamic Electrons in a Corbino Geometry
Creators: name: Farrell, Jack H.
name: Grisouard, Nicolas
name: Scaffidi, Thomas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Hydrodynamic electrons flowing through a two-dimensional channel are predicted to undergo a plasma instability above a critical drift velocity. This Dyakonov-Shur (DS) instability terminates as a coherent nonlinear oscillator which shows promise as a source of radiation that could fill the so-called TeraHertz gap. In this work, we study radial flow in a Corbino disk, and demonstrate how the DS instability is substantially enhanced in this geometry, both in terms of a lower critical drift velocity and a higher generated power. Interestingly, hydrodynamic electron flows were recently reported in a graphene sample of this geometry, and our results are therefore directly relevant to current efforts to detect this experimentally elusive phenomenon. The analysis is based on a hydrodynamic approach and features both linearized calculations as well as full numerical simulations of the Navier-Stokes equation.
description: 8 pages, 5 figures
Auswertung der Versuche von Dipl.-Ing. Matthias
Creators: name: Fritzsche, Elmar
Publisher: name: TUHH Universitätsbibliothek
Year: 1958
Subjects: subject: Versuch Hydrodynamik
subject: Platte
subject: Druckmittelpunkt
classificationCode: 52.00
subject: Maschinenbau, Energietechnik, Fertigungstechnik: Allgemeines

description: Auswertung der Versuche von Dipl.-Ing. Matthias
Minimizing the Switch and Link Conflicts in an Optical Multi-stage Interconnection Network
Creators: name: Bhardwaj, Ved Prakash
name: Nitin
name: Tyagi, Vipin
Publisher: name: arXiv
Year: 2012
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Multistage Interconnection Networks (MINs) are very popular in switching and communication applications. A MIN connects N inputs to N outputs and is referred as an N \times N MIN; having size N. Optical Multistage Interconnection Network (OMIN) represents an important class of Interconnection networks. Crosstalk is the basic problem of OMIN. Switch Conflict and Link Conflict are the two main reason of crosstalk. In this paper, we are considering both problems. A number of techniques like Optical window, Improved Window, Heuristic, Genetic, and Zero have been proposed earlier in this research domain. In this paper, we have proposed two algorithms called Address Selection Algorithm and Route Selection Algorithm (RSA). RSA is based on Improved Window Method. We have applied the proposed algorithms on existing Omega network, having shuffle-exchange connection pattern. The main functionality of ASA and RSA is to minimize the number of switch and link conflicts in the network and to provide conflict free routes.
description: 9 pages, 6 figures
Ice model and eight-vertex model on the two-dimensional Sierpinski gasket
Creators: name: Chang, Shu-Chiuan
name: Chen, Lung-Chi
name: Lee, Hsin-Yun
Publisher: name: arXiv
Year: 2012
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We present the numbers of ice model and eight-vertex model configurations (with Boltzmann factors equal to one), I(n) and E(n) respectively, on the two-dimensional Sierpinski gasket SG(n) at stage $n$. For the eight-vertex model, the number of configurations is $E(n)=2^{3(3^n+1)/2}$ and the entropy per site, defined as $\lim_{v \to \infty} \ln E(n)/v$ where $v$ is the number of vertices on SG(n), is exactly equal to $\ln 2$. For the ice model, the upper and lower bounds for the entropy per site $\lim_{v \to \infty} \ln I(n)/v$ are derived in terms of the results at a certain stage. As the difference between these bounds converges quickly to zero as the calculated stage increases, the numerical value of the entropy can be evaluated with more than a hundred significant figures accurate. The corresponding result of ice model on the generalized two-dimensional Sierpinski gasket SG_b(n) with $b=3$ is also obtained. For the generalized vertex model on SG_3(n), the number of configurations is $2^{(8 \times 6^n +7)/5}$ and the entropy per site is equal to $\frac87 \ln 2$. The general upper and lower bounds for the entropy per site for arbitrary $b$ are conjectured.
description: 20 pages, 6 figures, 2 tables
Assessing $TESS$'s Yield of Rocky Planets Around Nearby M Dwarfs
Creators: name: Brady, Madison
name: Bean, Jacob
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Terrestrial planets are easier to detect around M dwarfs than other types of stars, making them promising for next-generation atmospheric characterization studies. The $TESS$ mission has greatly increased the number of known M dwarf planets that we can use to perform population studies, allowing us to explore how the rocky planet occurrence rate varies with host radius, following in the footsteps of past work with $Kepler$ data. In this paper, we use simulations to assess $TESS$'s yield of small ($0.5\,R_\oplus \,<\,R_p\,<\,2\,R_\oplus$) planet candidates around nearby ($d\,<\,30$ pc) M dwarfs. We highlight the underappreciated fact that while $TESS$ was indeed expected to find a large number of planets around M dwarfs overall, it was not expected to have a high planetary yield for the latest M dwarfs. Furthermore, we find that $TESS$ has detected fewer planets around stars with $R_*\,<\,0.3 R_\odot$ than even was expected (11 observed vs. $24\,\pm\,5$ expected). We find evidence that the photometric noise of stars in the $TESS$ bandpass increases with decreasing radius for M dwarfs. However, this trend cannot explain the observed distribution of planets. Our main conclusions are: (1) the planet occurrence rate likely doesn't increase, and may decrease for the latest M dwarfs; and (2) there are at least 17, and potentially three times that number, transiting planets around nearby late M dwarfs that still won't be detected by the end of $TESS$'s 4th year.
description: 16 pages, 4 figures, 1 table. Accepted for publication in AJ, edits for clarity and flow incorporated
Quantum teleportation between moving detectors in a quantum field
Creators: name: Lin, Shih-Yuin
name: Shiokawa, Kazutomu
name: Chou, Chung-Hsien
name: Hu, B. L.
Publisher: name: arXiv
Year: 2012
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider the quantum teleportation of continuous variables modeled by Unruh-DeWitt detectors coupled to a common quantum field initially in the Minkowski vacuum. An unknown coherent state of an Unruh-DeWitt detector is teleported from one inertial agent (Alice) to an almost uniformly accelerated agent (Rob, for relativistic motion), using a detector pair initially entangled and shared by these two agents. The averaged physical fidelity of quantum teleportation, which is independent of the observer's frame, always drops below the best fidelity value from classical teleportation before the detector pair becomes disentangled with the measure of entanglement evaluated around the future lightcone of the joint measurement event by Alice. The distortion of the quantum state of the entangled detector pair from the initial state can suppress the fidelity significantly even when the detectors are still strongly entangled around the lightcone. We point out that the dynamics of entanglement of the detector pair observed in Minkowski frame or in quasi-Rindler frame are not directly related to the physical fidelity of quantum teleportation in our setup. These results are useful as a guide to making judicious choices of states and parameter ranges and estimation of the efficiency of quantum teleportation in relativistic quantum systems under environmental influences.
description: 18 pages, 7 figures
BL Lacertae objects beyond redshift 1.3 - UV-to-NIR photometry and photometric redshift for Fermi/LAT blazars
Creators: name: Rau, Arne
name: Schady, P.
name: Greiner, J.
name: Salvato, M.
name: Ajello, M.
name: Bottacini, E.
name: Gehrels, N.
name: Afonso, P. M. J.
name: Elliott, J.
name: Filgas, R.
name: Kann, D. A.
name: Klose, S.
name: Kruehler, Thomas
name: Nardini, M.
name: Guelbenzu, A. Nicuesa
name: E., F. Olivares
name: Rossi, A.
name: Sudilovsky, V.
name: Updike, A. C.
name: Hartmann, D. H.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Observations of the gamma-ray sky with Fermi led to significant advances towards understanding blazars, the most extreme class of Active Galactic Nuclei. A large fraction of the population detected by Fermi is formed by BL Lacertae (BL Lac) objects, whose sample has always suffered from a severe redshift incompleteness due to the quasi-featureless optical spectra. Our goal is to provide a significant increase of the number of confirmed high-redshift BL Lac objects contained in the 2 LAC Fermi/LAT catalog. For 103 Fermi/LAT blazars, photometric redshifts using spectral energy distribution fitting have been obtained. The photometry includes 13 broad-band filters from the far ultraviolet to the near-IR observed with Swift/UVOT and the multi-channel imager GROND at the MPG/ESO 2.2m telescope. Data have been taken quasi-simultaneously and the remaining source-intrinsic variability has been corrected for. We release the UV-to-near-IR 13-band photometry for all 103 sources and provide redshift constraints for 75 sources without previously known redshift. Out of those, eight have reliable photometric redshifts at z>1.3, while for the other 67 sources we provide upper limits. Six of the former eight are BL Lac objects, which quadruples the sample of confirmed high-redshift BL Lac. This includes three sources with redshifts higher than the previous record for BL Lac, including CRATES J0402-2615 with the best-fit solution at z~1.9.
description: Uploaded correct Fig 4. Changed counterpart name for 2FGLJ0537.7-5716 from PKS 0541-834 (different source) to SUMSS J053748-571828
Efficient Simulation of Dynamics in Two-Dimensional Quantum Spin Systems with Isometric Tensor Networks
Creators: name: Lin, Sheng-Hsuan
name: Zaletel, Michael
name: Pollmann, Frank
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the computational power of the recently introduced class of isometric tensor network states (isoTNSs), which generalizes the isometric conditions of the canonical form of one-dimensional matrix-product states to tensor networks in higher dimensions. We discuss several technical details regarding the implementation of isoTNSs-based algorithms and compare different disentanglers -- which are essential for an efficient handling of isoTNSs. We then revisit the time evolving block decimation for isoTNSs ($\text{TEBD}^2$) and explore its power for real time evolution of two-dimensional (2D) lattice systems. Moreover, we introduce a density matrix renormalization group algorithm for isoTNSs ($\text{DMRG}^2$) that allows to variationally find ground states of 2D lattice systems. As a demonstration and benchmark, we compute the dynamical spin structure factor of 2D quantum spin systems for two paradigmatic models: First, we compare our results for the transverse field Ising model on a square lattice with the prediction of the spin-wave theory. Second, we consider the Kitaev model on the honeycomb lattice and compare it to the result from the exact solution.
description: 16 pages, 11 figures, 1 table (+appendix: 6 pages, 2 figure, 2 table)
Magnetic structure determination of Ca$_3$LiOsO$_6$ using neutron and x-ray scattering
Creators: name: Calder, S.
name: Lumsden, M. D.
name: Garlea, V. O.
name: Kim, J. -W.
name: Shi, Y. G.
name: Feng, H. L.
name: Yamaura, K.
name: Christianson, A. D.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We present a neutron and x-ray scattering investigation of Ca$_3$LiOsO$_6$, a material predicted to host magnetic ordering solely through an extended superexchange pathway involving two anions, an interaction mechanism that has undergone relatively little investigation. This contrasts with the ubiquitous superexchange interaction mechanism involving a single anion that has well defined and long standing rules. Despite the apparent 1D nature and triangular units of magnetic osmium ions the onset of magnetic correlations has been observed at a high temperature of 117 K in bulk measurements. We experimentally determine the magnetically ordered structure and show it to be long range and three dimensional. Our results support the model of extended superexchange interaction.
Melting of generalized Wigner crystals in transition metal dichalcogenide heterobilayer Moiré systems
Creators: name: Matty, Michael
name: Kim, Eun-Ah
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Moiré superlattice systems such as transition metal dichalcogenide heterobilayers have garnered significant recent interest due to their promising utility as tunable solid state simulators. Recent experiments on a WSe$_2$/WS$_2$ heterobilayer detected incompressible charge ordered states that one can view as generalized Wigner crystals. The tunability of the hetero-TMD Moiré system presents an opportunity to study the rich set of possible phases upon melting these charge-ordered states. Here we use Monte Carlo simulations to study these intermediate phases in between incompressible charge-ordered states in the strong coupling limit. We find two distinct stripe solid states to be each preceded by distinct types of nematic states. In particular, we discover microscopic mechanisms that stabilize each of the nematic states, whose order parameter transforms as the two-dimensional $E$ representation of the Moiré lattice point group. Our results provide a testable experimental prediction of where both types of nematic occur, and elucidate the microscopic mechanism driving their formation.
Negative Refractive Index in Hydrodynamical Systems
Creators: name: Amariti, Antonio
name: Forcella, Davide
name: Mariotti, Alberto
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Optics (physics.optics)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: We discuss the presence of exotic electromagnetic phenomena in systems with finite charge density which are described by hydrodynamics. We show that such systems generically have negative refractive index for low frequency electromagnetic waves, i.e. the energy flux and the phase velocity of the wave propagate in opposite directions. We comment on possible phenomenological applications, focusing on the Quark Gluon Plasma.
description: 16 pages, 2 figures
Topological Random Fractals
Creators: name: Ivaki, Moein N.
name: Sahlberg, Isac
name: Pöyhönen, Kim
name: Ojanen, Teemu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We introduce the notion of topological electronic states on random lattices in non-integer dimensions. By considering a class $D$ model on critical percolation clusters embedded in two dimensions, we demonstrate that these topological random fractals exhibit a robust mobility gap, support quantized conductance and represent a well-defined thermodynamic phase of matter. The finite-size scaling analysis further suggests that the critical properties are not consistent with the class $D$ systems in two dimensions. Our results establish topological random fractals as the most complex systems known to support nontrivial band topology with their distinct unique properties.
description: 6 pages, 5 figures
Zwischen Mission und Markt - Ansgars Kirchen im Norden
Creators: name: Dobat, Andres S.
Publisher: name: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts
Year: 2020

description: -
description: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts, Bd. 88 2010(2013)
Information Complexity and Estimation
Creators: name: Baron, Dror
Publisher: name: arXiv
Year: 2011
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: We consider an input $x$ generated by an unknown stationary ergodic source $X$ that enters a signal processing system $J$, resulting in $w=J(x)$. We observe $w$ through a noisy channel, $y=z(w)$; our goal is to estimate x from $y$, $J$, and knowledge of $f_{Y|W}$. This is universal estimation, because $f_X$ is unknown. We provide a formulation that describes a trade-off between information complexity and noise. Initial theoretical, algorithmic, and experimental evidence is presented in support of our approach.
description: Appears at WITMSE 2011, The Fourth Workshop on Information Theoretic Methods in Science and Engineering, 7-10 August 2011, Helsinki, Finland. Note that the WITMSE version is 4 pages, owing to different formatting
§ 11 Wertschöpfung als Maßstab zwischenstaatlicher Verteilungsgerechtigkeit
Creators: name: Klamet, Johannes
Publisher: name: Heidelberger Beiträge zum Finanz- und Steuerrecht
Year: 2020

description: Heidelberger Beiträge zum Finanz- und Steuerrecht, Bd. 13 (2019): Geprägte Freiheit 2019/20
Rhein-weser-germanische Scheiterhaufengräber bei Mehle (Lkr. Hildesheim) mit einem römischen Kochtopf der Okkupationszeit und dessen kulturgeschichtlicher Hintergrund
Creators: name: Cosack, Erhard
name: Rudnick, Bernhard
Publisher: name: Jahrbuch des Römisch-Germanischen Zentralmuseums Mainz
Year: 2020

description: Jahrbuch des Römisch-Germanischen Zentralmuseums Mainz, Bd. 61 Nr. 1 (2014)
Search for a Narrow ttbar Resonance in ppbar Collisions at sqrt{s}=1.96 TeV
Creators: name: D0 Collaboration
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We report a search for a narrow ttbar resonance that decays into a lepton+jets final state based on an integrated luminosity of 5.3/fb of proton-antiproton collisions at sqrt{s}=1.96 TeV collected by the D0 Collaboration at the Fermilab Tevatron Collider. We set upper limits on the production cross section of such a resonance multiplied by its branching fraction to ttbar which we compare to predictions for a leptophobic topcolor Z' boson. We exclude such a resonance at the 95% confidence level for masses below 835 GeV.
description: 7 pages, 3 figures, submitted to Physical Review Letters
Benchmarking single-photon sources from an auto-correlation measurement
Creators: name: Sekatski, Pavel
name: Oudot, Enky
name: Caspar, Patrik
name: Thew, Rob
name: Sangouard, Nicolas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Here we argue that the probability that a given source produces exactly a single photon is a natural quantity to benchmark single-photon sources as it certifies the absence of multi-photon components and quantifies the efficiency simultaneously. Moreover, this probability can be bounded simply from an auto-correlation measurement -- a balanced beam splitter and two photon detectors. Such a bound gives access to various non-classicality witnesses that can be used to certify and quantify Wigner-negativity, in addition to non-Gaussianity and P-negativity of the state produced by the source. We provide tools that can be used in practice to account for an imperfect beam splitter, non-identical and non-unit detection efficiencies, dark counts and other imperfections, to take finite statistical effects into account without assuming that identical states are produced in all rounds, and optionally allow one to remove the detector inefficiencies from the analysis. We demonstrate the use of the proposed benchmark, non-classicality witness and measure using a heralded single-photon source based on spontaneous parametric down-conversion. We report on an average probability that a single photon is produced $\geq 55\%$ and an average measure of the Wigner negativity $\geq 0.004$ with a confidence level of $1-10^{-10}$.
description: 8+6 pages, 5 figures
The transfer matrix: a geometrical perspective
Creators: name: Sanchez-Soto, L. L.
name: Monzon, J. J.
name: Barriuso, A. G.
name: Carinena, J. F.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a comprehensive and self-contained discussion of the use of the transfer matrix to study propagation in one-dimensional lossless systems, including a variety of examples, such as superlattices, photonic crystals, and optical resonators. In all these cases, the transfer matrix has the same algebraic properties as the Lorentz group in a (2+1)-dimensional spacetime, as well as the group of unimodular real matrices underlying the structure of the abcd law, which explains many subtle details. We elaborate on the geometrical interpretation of the transfer-matrix action as a mapping on the unit disk and apply a simple trace criterion to classify the systems into three types with very different geometrical and physical properties. This approach is applied to some practical examples and, in particular, an alternative framework to deal with periodic (and quasiperiodic) systems is proposed.
description: 50 pages, 24 figures
Inhalt
Creators: name: Redaktion, Die
Publisher: name: Kunstchronik. Monatsschrift für Kunstwissenschaft, Museumswesen und Denkmalpflege
Year: 2020

description: Kunstchronik. Monatsschrift für Kunstwissenschaft, Museumswesen und Denkmalpflege, Bd. 21 Nr. 2 (1968): Kunstchronik. Monatsschrift für Kunstwissenschaft, Museumswesen und Denkmalpflege