cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Stochastic spikes and strong noise limits of stochastic differential equations
Creators: name: Bauer, Michel
name: Bernard, Denis
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Motivated by studies of indirect measurements in quantum mechanics, we investigate stochastic differential equations with a fixed point subject to an additional infinitesimal repulsive perturbation. We conjecture, and prove for an important class, that the solutions exhibit a universal behavior when time is rescaled appropriately: by fine-tuning of the time scale with the infinitesimal repulsive perturbation, the trajectories converge in a precise sense to spiky trajectories that can be reconstructed from an auxiliary time-homogeneous Poisson process. Our results are based on two main tools. The first is a time change followed by an application of Skorokhod's lemma. We prove an effective approximate version of this lemma of independent interest. The second is an analysis of first passage times, which shows a deep interplay between scale functions and invariant measures. We conclude with some speculations of possible applications of the same techniques in other areas.
Brief an Johann III Bernoulli
Creators: name: Henzi, Rudolf
Publisher: name: [s.n.]
Year: 1784

description: von [Rudolf Samuel] Henzi
description: Öffentliche Bibliothek der Universität Basel
description: Französisch
description: Verzeichnung=Description=Inventaire November 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Brief an Gottlieb Friedrich Templer
Creators: name: Güttner, Gottfried
Publisher: name: [s.n.]
Year: 1685

description: Adressat: Gottlieb Friedrich Templer entspricht Gottfried Kirch
description: von Gottfried Güt[t]ner
description: Mit rotem Siegel
description: Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Verzeichnung=Description=Inventaire November 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Beyond the Standard Model: Charting Fundamental Interactions via Lattice Simulations
Creators: name: Pica, Claudio
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: After the discovery of the Higgs boson, the primary objective of the Large Hadron Collider (LHC) experiments is to identify new physics beyond the Standard Model (SM). One of the most intriguing possibilities would be the discovery of non-perturbative phenomena in electroweak physics. In fact both ATLAS and CMS are providing crucial precision tests of the Higgs sector. Most strikingly, there is no conclusive evidence yet on whether the Higgs boson is elementary or composite. Lattice simulations can play a key role in advancing our theoretical understanding of strongly coupled gauge theories relevant for extensions of the SM and the LHC program. In this talk I will review the state of beyond the SM (BSM) lattice studies aimed to chart the phase diagram and to uncover the properties of strongly coupled gauge theories.
description: Plenary talk presented at the 34th International Symposium on Lattice Field Theory (Lattice 2016)
Ordering tendencies and electronic properties in quaternary Heusler derivatives
Creators: name: Neibecker, Pascal
name: Gruner, Markus E.
name: Xu, Xiao
name: Kainuma, Ryosuke
name: Petry, Winfried
name: Pentcheva, Rossitza
name: Leitner, Michael
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The phase stabilities and ordering tendencies in the quaternary full-Heusler alloys NiCoMnAl and NiCoMnGa have been investigated by in-situ neutron diffraction, calorimetry and magnetization measurements. NiCoMnGa was found to adopt the L2$_1$ structure, with distinct Mn and Ga sublattices but a common Ni-Co sublattice. A second-order phase transition to the B2 phase with disorder also between Mn and Ga was observed at 1160 K. In contrast, in NiCoMnAl slow cooling or low-temperature annealing treatments are required to induce incipient L2$_1$ ordering, otherwise the system displays only B2 order. Linked to this L2$_1$ ordering, a drastic increase in the magnetic transition temperature was observed in NiCoMnAl, while annealing affected the magnetic behavior of NiCoMnGa only weakly due to the low degree of quenched-in disorder. First principles calculations were employed to study the thermodynamics as well as order-dependent electronic properties of both compounds. It was found that a near half-metallic pseudo-gap emerges in the minority spin channel only for the completely ordered Y structure, which however is energetically unstable compared to the predicted ground state of a tetragonal structure with alternating layers of Ni and Co. The experimental inaccessibility of the totally ordered structures is explained by kinetic limitations due to the low ordering energies.
Brief an Johann Gabriel Doppelmayr
Creators: name: Grammaticus, Nicasius
Publisher: name: [s.n.]
Year: 1725

description: von Nicasio Grammatici
description: Bl. 482: leer
description: Öffentliche Bibliothek der Universität Basel
description: Lateinisch
description: Verzeichnung=Description=Inventaire November 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Brief an Johann III Bernoulli
Creators: name: Gemmingen-Guttenberg, Karl Friedrich Reinhard
Publisher: name: [s.n.]
Year: 1788

description: von [Karl Friedrich Reinhard] von Gemmingen
description: Öffentliche Bibliothek der Universität Basel
description: Französisch
description: Verzeichnung=Description=Inventaire November 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Universality and the dynamical space-time dimensionality in the Lorentzian type IIB matrix model
Creators: name: Ito, Yuta
name: Nishimura, Jun
name: Tsuchiya, Asato
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: The type IIB matrix model is one of the most promising candidates for a nonperturbative formulation of superstring theory. In particular, its Lorentzian version was shown to exhibit an interesting real-time dynamics such as the spontaneous breaking of the 9-dimensional rotational symmetry to the 3-dimensional one. This result, however, was obtained after regularizing the original matrix integration by introducing "infrared" cutoffs on the quadratic moments of the Hermitian matrices. In this paper, we generalize the form of the cutoffs in such a way that it involves an arbitrary power ($2p$) of the matrices. By performing Monte Carlo simulation of a simplified model, we find that the results become independent of $p$ and hence universal for $p \gtrsim 1.3$. For $p$ as large as 2.0, however, we find that large-$N$ scaling behaviors do not show up, and we cannot take a sensible large-$N$ limit. Thus we find that there is a certain range of $p$ in which a universal large-$N$ limit can be taken. Within this range of $p$, the dynamical space-time dimensionality turns out to be $(3+1)$, while for $p=2.0$, where we cannot take a sensible large-$N$ limit, we observe a (5+1)d structure.
description: 20 pages, 26 figures
Brief an Johann III Bernoulli
Creators: name: Gemmingen-Guttenberg, Karl Friedrich Reinhard
Publisher: name: [s.n.]
Year: 1781

description: von [Karl Friedrich Reinhard] von Gemmingen
description: Unterschrift Autograph
description: Öffentliche Bibliothek der Universität Basel
description: Französisch
description: Verzeichnung=Description=Inventaire November 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Event Stream-Based Process Discovery using Abstract Representations
Creators: name: van Zelst, Sebastiaan J.
name: van Dongen, Boudewijn F.
name: van der Aalst, Wil M. P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Databases (cs.DB)
subject: Artificial Intelligence (cs.AI)
subject: Data Structures and Algorithms (cs.DS)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: The aim of process discovery, originating from the area of process mining, is to discover a process model based on business process execution data. A majority of process discovery techniques relies on an event log as an input. An event log is a static source of historical data capturing the execution of a business process. In this paper we focus on process discovery relying on online streams of business process execution events. Learning process models from event streams poses both challenges and opportunities, i.e. we need to handle unlimited amounts of data using finite memory and, preferably, constant time. We propose a generic architecture that allows for adopting several classes of existing process discovery techniques in context of event streams. Moreover, we provide several instantiations of the architecture, accompanied by implementations in the process mining tool-kit ProM (http://promtools.org). Using these instantiations, we evaluate several dimensions of stream-based process discovery. The evaluation shows that the proposed architecture allows us to lift process discovery to the streaming domain.
description: Accepted for publication in "Knowledge and Information Systems; " (Springer: http://link.springer.com/journal/10115)
Brief an Johann III Bernoulli
Creators: name: Gemmingen-Guttenberg, Karl Friedrich Reinhard
Publisher: name: [s.n.]
Year: 1787

description: von [Karl Friedrich Reinhard] von Gemmingen
description: Unterschrift Autograph
description: Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Verzeichnung=Description=Inventaire November 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Rotating solitons supported by a spiral waveguide
Creators: name: Petrovic, Milan S.
name: Strinic, Aleksandra I.
name: Aleksic, Najdan B.
name: Belic, Milivoj R.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We investigate numerically light propagation in a single spiral waveguide formed in a nonlinear photorefractive medium for a low spatial frequency of the waveguide rotation. We present the general procedure for finding solitonic solutions in spiral waveguiding structures, as well as the variational approach to calculate soliton parameters analytically. Solitons supported by the spiral waveguide perform robust stable rotational oscillatory motion, with the period predicted by their static characteristics, without any signatures of wave radiation or soliton decay over many rotation periods and diffraction lengths.
description: 9 pages, 10 figures, submitted to PRA
Recent Developments in Non-Fermi Liquid Theory
Creators: name: Lee, Sung-Sik
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Non-Fermi liquids arise when metals are subject to singular interactions mediated by soft collective modes. In the absence of well-defined quasiparticle, universal physics of non-Fermi liquids is captured by interacting field theories which replace Landau Fermi liquid theory. In this review, we discuss two approaches that have been recently developed for non-Fermi liquid theory with emphasis on two space dimensions. The first is a perturbative scheme based on a dimensional regularization, which achieves a controlled access to the low-energy physics by tuning the number of co-dimensions of Fermi surface. The second is a non-perturbative approach which treats the interaction ahead of the kinetic term through a non-Gaussian scaling called interaction-driven scaling. Examples of strongly coupled non-Fermi liquids amenable to exact treatments through the interaction-driven scaling are discussed.
description: 23 pages; comments are welcome
Liverpool Community, 1649-1750
Creators: name: Ascott, D.
name: Lewis, F.
name: Power, M.
Publisher: name: UK Data Service
Year: 1998

description: The purpose of the project was to investigate the character of Liverpool society during the first century of its rapid commercial expansion, and in particular to address the question whether its social characteristics help to explain the dynamic nature of its economic growth. The particular questions addressed include the origins of in-migrants to Liverpool, occupational structure and change, family and business networks, and the character of the governing elite and their use of power. The method was to input major sources for the history of Liverpool into computer files, to link names and compile information about Liverpool inhabitants. This allowed information to be built up about geographical origins, occupations, wealth, residential location, family and business or political networks and inter-generational continuity in the town.
Brief an Johann Pfeiffer
Creators: name: Geier, Martin
Publisher: name: [s.n.]
Year: 1666

description: von Mart[in] Geier
description: Öffentliche Bibliothek der Universität Basel
description: Lateinisch
description: Verzeichnung=Description=Inventaire November 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Brief an Johann III Bernoulli
Creators: name: Gemmingen-Guttenberg, Karl Friedrich Reinhard
Publisher: name: [s.n.]
Year: 1787

description: von [Karl Friedrich Reinhard] von Gemmingen
description: Unterschrift Autograph
description: Öffentliche Bibliothek der Universität Basel
description: Französisch
description: Verzeichnung=Description=Inventaire November 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Brief an Johann III Bernoulli
Creators: name: Gemmingen-Guttenberg, Karl Friedrich Reinhard
Publisher: name: [s.n.]
Year: 1787

description: von [Karl Friedrich Reinhard] von Gemmingen
description: Öffentliche Bibliothek der Universität Basel
description: Französisch
description: Verzeichnung=Description=Inventaire November 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Brief an Johann III Bernoulli
Creators: name: Gessner, Johannes
Publisher: name: [s.n.]
Year: 1782

description: von Joh[annes] Gessner
description: Mit roter Oblate
description: Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Druck: Lambert, Johann Heinrich 1728-1777. - Joh. Heinrich Lamberts deutscher gelehrter Briefwechsel / herausg. von Joh. Bernoulli. - Berlin, 1787, 5, II, 266-267
description: Verzeichnung=Description=Inventaire Oktober 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Brief an J[ohann] II B[ernoulli]
Creators: name: Ivernois, Jean-Antoine d'
Publisher: name: [s.n.]
Year: 1756
Subjects: Bernoulli, Johann1744-1807

description: Bericht über das Befinden von Joh. III B., den Ivernois in Neuchâtel als Arzt betreut
description: von [Jean Antoine] d' Ivernois
description: Öffentliche Bibliothek der Universität Basel
description: Französisch
description: Datenimport aus LIDOS / Bernoulli (2004-07-02)
Brief an Johann II Bernoulli
Creators: name: [s.n.]
Publisher: name: [s.n.]
Year: 1765
Subjects: Tonnellé

description: Jadart spricht Bernoulli seine Dankbarkeit und Hochachtung aus. Empfiehlt ihm einen M. Tonnellé; dieser hat eine kleine Arbeit verfasst, die er vor der Drucklegung Bernoulli unterbreiten möchte.
description: von Jadart
description: Schreiberhand
description: Unterschrift eigenhändig
description: Öffentliche Bibliothek der Universität Basel
description: Französisch
description: Datenimport aus LIDOS / Bernoulli (2004-07-02)
Brief an Johann II Bernoulli
Creators: name: Jallabert, Jean
Publisher: name: [s.n.]
Year: 1759
Subjects: Basler, Jacob1725-1795
Bernoulli, Daniel1700-1782
Bernoulli, Susanna1715-1803
Fleurieu, C. P. Claret de1738-1810
Jallabert-Calandrini, Sybille-Cathérine18. Jh
Mallet, Jacques-André1740-1790

description: Empfehlung eines jungen Mannes, der bei J.B. studieren soll.
description: von Jean Jallabert
description: Siegel. Das Datum ergibt sich aus der Bemerkung Jallaberts, er habe einen 19-jährigen Sohn. François Jallabert ist 1740 geboren. Auf dem Umschlag des Konvolutes, das auch diesen Brief enthält, vermerkt Joh. III B.: "s.d. (vers 1758 ou 69)".
description: Öffentliche Bibliothek der Universität Basel
description: Französisch
description: Datenimport aus LIDOS / Bernoulli (2004-07-02)
Brief an Johann II Bernoulli
Creators: name: [s.n.]
Publisher: name: [s.n.]
Year: 1771
Subjects: Artus, d'

description: Jadart sendet zwei Probleme von d'Artus und bittet um Lösung.
description: von Jadart
description: Brief von Schreiberhand
description: Öffentliche Bibliothek der Universität Basel
description: Französisch
description: Datenimport aus LIDOS / Bernoulli (2004-07-02)
description: Bl. 34: Zwei Probleme von d'Artus: 1. Kürzester Weg von a nach b unter best., Bedingungen (ohne Differentialrechung zu bestimmen) 2. Wahrscheinlichkeitsproblem beim Spiel "Trente et quarante"
Brief an Johann II Bernoulli
Creators: name: [s.n.]
Publisher: name: [s.n.]
Year: 1771

description: Sendet Lösungsvorschlag eines seiner Ingenieure zu den Problemen von d'Artus
description: von Jadart
description: Öffentliche Bibliothek der Universität Basel
description: Französisch
description: Datenimport aus LIDOS / Bernoulli (2004-07-02)
Post-Lie algebras and factorization theorems
Creators: name: Ebrahimi-Fard, Kurusch
name: Mencattini, Igor
name: Munthe-Kaas, Hans
Publisher: name: arXiv
Year: 2017
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 16T05, 16T10, 16T25, 16T30, 17D25

description: In this note we further explore the properties of universal enveloping algebras associated to a post-Lie algebra. Emphasizing the role of the Magnus expansion, we analyze the properties of group like-elements belonging to (suitable completions) of those Hopf algebras. Of particular interest is the case of post-Lie algebras defined in terms of solutions of modified classical Yang-Baxter equations. In this setting we will study factorization properties of the aforementioned group-like elements.
Brief an Gottfried Kirch
Creators: name: Ihle, Johann Abraham
Publisher: name: [s.n.]
Year: 1702

description: von Johann Abraham Ihle
description: Mit einer Notiz von Kirch
description: Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Verzeichnung=Description=Inventaire Dez. 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Sixteen years of X-ray monitoring of Sagittarius A*: Evidence for a decay of the faint flaring rate from 2013 August, 13 months before a rise in the bright flaring rate
Creators: name: Mossoux, Enmanuelle
name: Grosso, Nicolas
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Recently, in a study the X-ray flaring activity of Sgr A* with Chandra and XMM-Newton public observations from 1999 to 2014 and 2014 Swift data, it has been argued that the "bright and very bright" flaring rate raised from 2014 Aug. 31. Thanks to 482ks of observations performed in 2015 with Chandra, XMM-Newton and Swift, we test the significance of this rise of flaring rate and determine the threshold of unabsorbed flare flux or fluence leading to any flaring-rate change. The mean unabsorbed fluxes of the 107 flares detected in the 1999-2015 observations are consistently computed from the extracted spectra and calibration files, assuming the same spectral parameters. We construct the observed flare fluxes and durations distribution for the XMM-Newton and Chandra flares and correct it from the detection biases to estimate the intrinsic distribution from which we determine the average flare detection efficiency for each observation. We apply the BB algorithm on the flare arrival times corrected from the corresponding efficiency. We confirm a constant overall flaring rate in 1999-2015 and a rise in the flaring rate for the most luminous/energetic flares from 2014 Aug. 31 (4 months after the passage of the DSO/G2 close to Sgr A*). We also identify a decay of the flaring rate for the less luminous and less energetic flares from 2013 Aug. and Nov., respectively (10 and 7 months before the pericenter of the DSO/G2). The decay of the faint flaring rate is difficult to explain by the tidal disruption of the DSO/G2, whose stellar nature is now well established, since it occurred well before its pericenter. Moreover, a mass transfer from the DSO/G2 to Sgr A* is not required to produce the rise in the bright flaring rate since the energy saved by the decay of the number of faint flares during a long time period may be later released by several bright flares during a shorter time period. (abridged)
description: Accepted in A&A in 2017 April 23
Brief an Gottfried Kirch
Creators: name: Ihle, Johann Abraham
Publisher: name: [s.n.]
Year: 1700

description: von Johann Abraham Ihle
description: Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Verzeichnung=Description=Inventaire Dez. 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Brief an Gottfried Kirch
Creators: name: Ihle, Johann Abraham
Publisher: name: [s.n.]
Year: 1703

description: von Johann Abraham Ihle
description: Mit Notiz von Kirch
description: Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Verzeichnung=Description=Inventaire Dez. 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Ising-type Magnetic Anisotropy in CePd$_2$As$_2$
Creators: name: Ajeesh, M. O.
name: Shang, T.
name: Jiang, W. B.
name: Xie, W.
name: Reis, R. D. dos
name: Smidman, M.
name: Geibel, C.
name: Yuan, H. Q.
name: Nicklas, M.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We investigated the anisotropic magnetic properties of CePd$_2$As$_2$ by magnetic, thermal and electrical transport studies. X-ray diffraction confirmed the tetragonal ThCr$_2$Si$_2$-type structure and the high-quality of the single crystals. Magnetisation and magnetic susceptibility data taken along the different crystallographic directions evidence a huge crystalline electric field (CEF) induced Ising-type magneto-crystalline anisotropy with a large $c$-axis moment and a small in-plane moment at low temperature. A detailed CEF analysis based on the magnetic susceptibility data indicates an almost pure $\langle\pm5/2 \rvert$ CEF ground-state doublet with the dominantly $\langle\pm3/2 \rvert$ and the $\langle\pm1/2 \rvert$ doublets at 290 K and 330 K, respectively. At low temperature, we observe a uniaxial antiferromagnetic (AFM) transition at $T_N=14.7$ K with the crystallographic $c$-direction being the magnetic easy-axis. The magnetic entropy gain up to $T_N$ reaches almost $R\ln2$ indicating localised $4f$-electron magnetism without significant Kondo-type interactions. Below $T_N$, the application of a magnetic field along the $c$-axis induces a metamagnetic transition from the AFM to a field-polarised phase at $μ_0H_{c0}=0.95$ T, exhibiting a text-book example of a spin-flip transition as anticipated for an Ising-type AFM.
description: 9 Pages, 8 figures
Brief an Gottfried Kirch
Creators: name: Ihle, Johann Abraham
Publisher: name: [s.n.]
Year: 1681

description: von Johann Abraham Ihle
description: Mit rotem Lacksiegel
description: Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Verzeichnung=Description=Inventaire Dez. 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Multilevel Monte Carlo Simulation of the Eddy Current Problem With Random Parameters
Creators: name: Galetzka, Armin
name: Bontinck, Zeger
name: Römer, Ulrich
name: Schöps, Sebastian
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: The multilevel Monte Carlo method is applied to an academic example in the field of electromagnetism. The method exhibits a reduced variance by assigning the samples to multiple models with a varying spatial resolution. For the given example it is found that the main costs of the method are spent on the coarsest level.
description: Applied Computational Electromagnetics Society Symposium - Italy (ACES), 2017 International, http://ieeexplore.ieee.org/document/7916062/
Angular Velocity Perturbations Inducing the Papaloizou-Pringle Instability and QPOs in the Torus around the Black Hole
Creators: name: Donmez, Orhan
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: A numerical study of the dynamic of the nonselfgravitating, unmagnetized, nonaxisymmetric, and rotating the torus around the non-rotating black hole is presented. We investigate the instability of the rotating torus subject to perturbations presented by increasing or decreasing the angular velocity of the stable torus. We have done, for the first time, an extensive analysis of the torus dynamic response to the perturbation of the angular velocity of the stable torus. We show how the high, moderate, and low values of the perturbations affect the torus dynamic and help us to understand the properties of the instability and Quasi-Periodic Oscillation (QPO). Our numerical simulations indicate the presence of Papaloizou-Pringle instability (PPI) with global m=1 mode and QPOs for the moderate and lower values of the perturbations on the angular velocity of the stable torus. Furthermore, with the lower values of the perturbations, the torus can lead to a wiggling initially and then PPI is produced in it. Finally, the matter of the torus would be dissipated due to the presence of a strong torque.
description: 9 pages, 11 figures
Brief an Gottfried Kirch
Creators: name: Ihle, Johann Abraham
Publisher: name: [s.n.]
Year: 1702

description: von Johann Abraham Ihle
description: Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Verzeichnung=Description=Inventaire Dez. 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Brief an Gottfried Kirch
Creators: name: Ihle, Johann Abraham
Publisher: name: [s.n.]
Year: 1703

description: von Johann Abraham Ihle
description: Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Verzeichnung=Description=Inventaire Dez. 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
On Lattice Calculation of Electric Dipole Moments and Form Factors of the Nucleon
Creators: name: Abramczyk, M.
name: Aoki, S.
name: Blum, T.
name: Izubuchi, T.
name: Ohki, H.
name: Syritsyn, S.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We analyze commonly used expressions for computing the nucleon electric dipole form factors (EDFF) $F_3$ and moments (EDM) on a lattice and find that they lead to spurious contributions from the Pauli form factor $F_2$ due to inadequate definition of these form factors when parity mixing of lattice nucleon fields is involved. Using chirally symmetric domain wall fermions, we calculate the proton and the neutron EDFF induced by the CP-violating quark chromo-EDM interaction using the corrected expression. In addition, we calculate the electric dipole moment of the neutron using background electric field that respects time translation invariance and boundary conditions, and find that it decidedly agrees with the new formula but not the old formula for $F_3$. Finally, we analyze some selected lattice results for the nucleon EDM and observe that after the correction is applied, they either agree with zero or are substantially reduced in magnitude, thus reconciling their difference from phenomenological estimates of the nucleon EDM.
description: 27 pages, 25 figures
CaloCube: a novel calorimeter for high-energy cosmic rays in space
Creators: name: Cattaneo, P. W.
name: Adriani, O.
name: Albergo, S.
name: Auditore, L.
name: Basti, A.
name: Berti, E.
name: Bigongiari, G.
name: Bonechi, L.
name: Bonechi, S.
name: Bongi, M.
name: Bonvicini, V.
name: Bottai, S.
name: Brogi, P.
name: Carotenuto, G.
name: Castellini, G.
name: ďAlessandro, R.
name: Detti, S.
name: Fasoli, M.
name: Finetti, N.
name: Italiano, A.
name: Lenzi, P.
name: Maestro, P.
name: Marrocchesi, P. S.
name: Mori, N.
name: Olmi, M.
name: Orzan, G.
name: Pacini, L.
name: Papini, P.
name: Pellegriti, M. G.
name: Rappoldi, A.
name: Ricciarini, S.
name: Rossella, M.
name: Sciutto, A.
name: Spillantini, P.
name: Starodubtsev, O.
name: Stolzi, F.
name: Suh, J. E.
name: Sulaj, A.
name: Tiberio, A.
name: Tricomi, A.
name: Trifiró, A.
name: Trimarchi, M.
name: Vannuccini, E.
name: Vedda, A.
name: Zampa, G.
name: Zampa, N.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: In order to extend the direct observation of high-energy cosmic rays up to the PeV region, highly performing calorimeters with large geometrical acceptance and high energy resolution are required. Within the constraint of the total mass of the apparatus, crucial for a space mission, the calorimeters must be optimized with respect to their geometrical acceptance, granularity and absorption depth. CaloCube is a homogeneous calorimeter with cubic geometry, to maximise the acceptance being sensitive to particles from every direction in space; granularity is obtained by relying on small cubic scintillating crystals as active elements. Different scintillating materials have been studied. The crystal sizes and spacing among them have been optimized with respect to the energy resolution. A prototype, based on CsI(Tl) cubic crystals, has been constructed and tested with particle beams. Some results of tests with different beams at CERN are presented.
description: Seven pages, seven pictures. Proceedings of INSTR17 Novosibirsk
Wurtzite spin lasers
Creators: name: Junior, Paulo E. Faria
name: Xu, Gaofeng
name: Chen, Yang-Fang
name: Sipahi, Guilherme M.
name: Žutić, Igor
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Semiconductor lasers are strongly altered by adding spin-polarized carriers. Such spin lasers could overcome many limitations of their conventional (spin-unpolarized) counterparts. While the vast majority of experiments in spin lasers employed zinc-blende semiconductors, the room temperature electrical manipulation was first demonstrated in wurtzite GaN-based lasers. However, the underlying theoretical description of wurtzite spin lasers is still missing. To address this situation, focusing on (In,Ga)N-based wurtzite quantum wells, we develop a theoretical framework in which the calculated microscopic spin-dependent gain is combined with a simple rate equation model. A small spin-orbit coupling in these wurtzites supports simultaneous spin polarizations of electrons and holes, providing unexplored opportunities to control spin lasers. For example, the gain asymmetry, as one of the key figures of merit related to spin amplification, can change the sign by simply increasing the carrier density. The lasing threshold reduction has a nonmonotonic depenedence on electron spin polarization, even for a nonvanishing hole spin polarization.
description: 10 pages, 8 figures
Lie structure of truncated symmetric Poisson algebras
Creators: name: Alves, Ilana Zuila Monteiro
name: Petrogradsky, Victor
Publisher: name: arXiv
Year: 2016
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 17B63, 17B50, 17B01, 17B30, 17B65, 16R10

description: The paper naturally continues series of works on identical relations of group rings, enveloping algebras, and other related algebraic structures. Let $L$ be a Lie algebra over a field of characteristic $p>0$. Consider its symmetric algebra $S(L)=\oplus_{n=0}^\infty U_n/U_{n-1}$, which is isomorphic to a polynomial ring. It also has a structure of a Poisson algebra, where the Lie product is traditionally denoted by $\{\ ,\ \}$. This bracket naturally induces the structure of a Poisson algebra on the ring $\mathbf{s}(L)=S(L)/(x^p\,|\, x\in L)$, which we call a truncated symmetric Poisson algebra. We study Lie identical relations of $\mathbf{s}(L)$. Namely, we determine necessary and sufficient conditions for $L$ under which $\mathbf{s}(L)$ is Lie nilpotent, strongly Lie nilpotent, solvable and strongly solvable, where we assume that $p>2$ to specify the solvability. We compute the strong Lie nilpotency class of $\mathbf{s}(L)$. Also, we prove that the Lie nilpotency class coincides with the strong Lie nilpotency class in case $p>3$. Shestakov proved that the symmetric algebra $S(L)$ of an arbitrary Lie algebra $L$ satisfies the identity $\{x,\{y,z\}\}\equiv 0$ if, and only if, $L$ is abelian. We extend this result for the (strong) Lie nilpotency and the (strong) solvability of $S(L)$. We show that the solvability of $\mathbf{s}(L)$ and $S(L)$ in case $\mathrm{char} K=2$ is different to other characteristics, namely, we construct examples of such algebras which are solvable but not strongly solvable. We use delta-sets for Lie algebras and the theory of identical relations of Poisson algebras. Also, we study filtrations in Poisson algebras and prove results on products of terms of the lower central series for Poisson algebras.
Measuring surface magnetic fields of red supergiant stars
Creators: name: Tessore, Benjamin
name: Lèbre, Agnès
name: Morin, Julien
name: Mathias, Philippe
name: Josselin, Eric
name: Aurière, Michel
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: RSG stars are very massive cool evolved stars. Recently, a weak magnetic field was measured at the surface of $α$ Ori and this is so far the only M-type supergiant for which a direct detection of a surface magnetic field has been reported. By extending the search for surface magnetic field in a sample of late-type supergiants, we want to determine whether the surface magnetic field detected on $α$ Ori is a common feature among the M-type supergiants. With the spectropolarimeter Narval at TBL we undertook a search for surface magnetic fields in a sample of cool supergiant stars, and we analysed circular polarisation spectra using the least-squares deconvolution technique. We detect weak Zeeman signatures of stellar origin in the targets CE Tau, $α^1$ Her and $μ$ Cep. For the latter star, we also show that cross-talk from the strong linear polarisation signals detected on this star must be taken into account. For CE Tau and $μ$ Cep, the longitudinal component of the detected surface fields is at the Gauss-level, such as in $α$~Ori. We measured a longitudinal field almost an order of magnitude stronger for $α^1$ Her. We also report variability of the longitudinal magnetic field of CE Tau and $α^1$ Her, with changes in good agreement with the typical atmospheric dynamics time-scales. We also report a non-detection of magnetic field at the surface of the yellow supergiant star $ρ$ Cas. The two RSG stars of our sample, CE Tau and $μ$ Cep, display magnetic fields very similar to that of $α$ Ori. The non-detection of a magnetic field on the post-RSG star $ρ$ Cas suggests that the magnetic field disappears, or at least becomes undetectable with present methods, at later evolutionary stages. Our analysis of $α^1$ Her supports the proposed reclassification of the star as an AGB star.
description: Accepted for publication in Astronomy and Astrophysics (2017 April 19)
Ketamine emulates altered visual processing found in schizophrenia
Creators: name: Schielke, Alexander
Publisher: name: No Publisher Supplied
Year: 2022

description: Animal models of mental disorders promote the development and evaluation of pharmacological interventions which ultimately improve the lives of the people who suffer from those disorder. The quality of life of people with schizophrenia is immensely affected by their disorder. While currently available treatments do reduce positive and negative symptoms in schizophrenia, they insufficiently improve cognitive symptoms and therefore inadequately improve quality of life. One hope is that animal models of schizophrenia can advance our understanding of the disorder and as a result lead the way to the discovery of new treatments. In this thesis I developed a nonhuman primate model of schizophrenia. One theory regarding schizophrenia is that some features in the disorder are the result of N-Methyl d-Aspartate receptor (NMDAR) hypofunction. Ketamine is an NMDAR antagonist and therefore serves as an experimental tool to investigate the consequences of NMDAR hypofunction. Therefore, I set out to test whether the effect of a low dose of ketamine on behavioral and electrophysiological aspects of visual perception in nonhuman primates (m. mulatta) matches findings in people with schizophrenia. The visual system of nonhuman primates is very close to that of humans which makes them uniquely suited to test predictions of the NMDAR hypofunction hypothesis on visual perception. I showed that after an injection of ketamine, visual contextual integration is reduced, in line with findings in schizophrenia. Furthermore, I showed that ketamine reduces steady state visual evoked responses, similar to what has been found in people with schizophrenia. Additionally, I developed a method to quantify gain, a ubiquitous feature of cortical processing, and show that ketamine reduces gain and gain control – processes that are impaired in schizophrenia. Finally, I discovered that full-screen flicker increases gain in nonhuman primates and replicated those findings in humans with EEG recordings. Together, my findings confirm that NMDAR hypofunction is a likely cause for altered visual perception in schizophrenia and show that ketamine is a useful tool to study NMDAR hypofunction in nonhuman primates. Moreover, my work suggests that full-screen flicker could remedy visual perception in schizophrenia and potentially other disorders that suffer from reduced gain control.
Extracting Lyapunov exponents from the echo dynamics of Bose-Einstein condensates on a lattice
Creators: name: Tarkhov, Andrei E.
name: Wimberger, Sandro
name: Fine, Boris V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Chaotic Dynamics (nlin.CD)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose theoretically an experimentally realizable method to demonstrate the Lyapunov instability and to extract the value of the largest Lyapunov exponent for a chaotic many-particle interacting system. The proposal focuses specifically on a lattice of coupled Bose-Einstein condensates in the classical regime describable by the discrete Gross-Pitaevskii equation. We suggest to use imperfect time-reversal of system's dynamics known as Loschmidt echo, which can be realized experimentally by reversing the sign of the Hamiltonian of the system. The routine involves tracking and then subtracting the noise of virtually any observable quantity before and after the time-reversal. We support the theoretical analysis by direct numerical simulations demonstrating that the largest Lyapunov exponent can indeed be extracted from the Loschmidt echo routine. We also discuss possible values of experimental parameters required for implementing this proposal.
Expansions of the solutions of the general Heun equation in terms of the incomplete Beta functions
Creators: name: Shahverdyan, T. A.
name: Red'kov, V. M.
name: Ishkhanyan, A. M.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Applying the approach based on the equation for the derivative, we construct several expansions of the solutions of the general Heun equation in terms of the incomplete Beta functions. Several expansions in terms of the Appell generalized hypergeometric functions of two variables of the fist kind are also presented. The constructed expansions are applicable for arbitrary sets of the involved parameters. The coefficients of the expansions obey four-, five- or six-term recurrence relations. However, there exist several sets of the parameters for which the recurrence relations involve fewer terms, not necessarily successive. The conditions for deriving finite-sum solutions via termination of the series are discussed.
description: arXiv admin note: text overlap with arXiv:1505.02178
Optical and near-infrared linear polarization of low and intermediate-gravity ultra-cool dwarfs
Creators: name: Miles-Páez, P. A.
name: Osorio, M. R. Zapatero
name: Pallé, E.
name: Ramírez, K. Peña
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We aim to study the optical and near-infrared linear polarimetric properties of a sample of young M7-L7 dwarfs ($\approx$1-500 Myr) with spectroscopic signatures of low- and intermediate-gravity atmospheres. We collected optical ($RIZ$) and near-infrared ($YJHK_{\rm s}$) linear polarimetry images on various time scales from $\sim$0.2 h to months. Linear polarization degrees in the interval 0-1.5\% ($I$- and $J$-bands) were measured with accuracies ranging from $\pm$0.1 $\%$ to $\pm$0.9 $\%$ depending on the observing filter and the target brightness. We found that the young field dwarfs in our sample show similar polarimetric degrees at both $I$- and $J$-bands, and that there is no obvious trend with the spectral type. The two Taurus sources in our sample show intense levels of $J$-band linear polarization probably due to surrounding disks. By compiling data from the literature for high-gravity M7-L7 dwarfs with likely ages $\ge$500 Myr, we did not observe any apparent difference in the linear polarimetry intensity between the young and old samples that could be ascribed to differing atmospheric gravities. Polarimetric variability with peak to peak amplitudes up to 1.5 $\%$ is detected on scales of about a rotation in two out of four targets that were monitored over several hours. Long-term polarimetric variability is also detected in nearly all dwarfs of the sample with data spanning months to years.
description: 16 pages, 9 figures, accepted in MNRAS
Brief an Gottfried Kirch
Creators: name: Ihle, Johann Abraham
Publisher: name: [s.n.]
Year: 1700

description: von Johann Abraham Ihle
description: Mit Oblate
description: Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Verzeichnung=Description=Inventaire Dez. 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Brief an Gottfried Kirch
Creators: name: Ihle, Johann Abraham
Publisher: name: [s.n.]
Year: 1698

description: von Johann Abraham Ihle
description: Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Verzeichnung=Description=Inventaire Dez. 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Brief an Gottfried Kirch
Creators: name: Ihle, Johann Abraham
Publisher: name: [s.n.]
Year: 1701

description: von Johann Abraham Ihle
description: Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Verzeichnung=Description=Inventaire Dez. 2014 HAN-Katalogisierungsregeln Vollständige Rekatalogisierung nach Standortverzeichnis und Briefkatalog
Resonances in a Chaotic Attractor Crisis of the Lorenz Flow
Creators: name: Tantet, Alexis
name: Lucarini, Valerio
name: Dijkstra, Henk A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Mathematical Physics (math-ph)
subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Local bifurcations of stationary points and limit cycles have successfully been characterized in terms of the critical exponents of these solutions. Lyapunov exponents and their associated covariant Lyapunov vectors have been proposed as tools for supporting the understanding of critical transitions in chaotic dynamical systems. However, it is in general not clear how the statistical properties of dynamical systems change across a boundary crisis during which a chaotic attractor collides with a saddle. This behavior is investigated here for a boundary crisis in the Lorenz flow, for which neither the Lyapunov exponents nor the covariant Lyapunov vectors provide a criterion for the crisis. Instead, the convergence of the time evolution of probability densities to the invariant measure, governed by the semigroup of transfer operators, is expected to slow down at the approach of the crisis. Such convergence is described by the eigenvalues of the generator of this semigroup, which can be divided into two families, referred to as the stable and unstable Ruelle-Pollicott resonances, respectively. The former describes the convergence of densities to the attractor (or escape from a repeller) and is estimated from many short time series sampling the phase space. The latter is responsible for the decay of correlations, or mixing, and can be estimated from a long times series, invoking ergodicity. It is found numerically for the Lorenz flow that the stable resonances do approach the imaginary axis during the crisis, as is indicative of the loss of global stability of the attractor. On the other hand, the unstable resonances, and a fortiori the decay of correlations, do not ag the proximity of the crisis, thus questioning the usual design of early warning indicators of boundary crises of chaotic attractors and the applicability of response theory close to such crises.
On the estimation of the current density in space plasmas: multi versus single-point techniques
Creators: name: Perri, Silvia
name: Valentini, Francesco
name: Sorriso-Valvo, Luca
name: Reda, Antonio
name: Malara, Francesco
Publisher: name: arXiv
Year: 2017
Subjects: subject: Space Physics (physics.space-ph)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Thanks to multi-spacecraft mission, it has recently been possible to directly estimate the current density in space plasmas, by using magnetic field time series from four satellites flying in a quasi perfect tetrahedron configuration. The technique developed, commonly called 'curlometer' permits a good estimation of the current density when the magnetic field time series vary linearly in space. This approximation is generally valid for small spacecraft separation. The recent space missions Cluster and Magnetospheric Multiscale (MMS) have provided high resolution measurements with inter-spacecraft separation up to 100 km and 10 km, respectively. The former scale corresponds to the proton gyroradius/ion skin depth in 'typical' solar wind conditions, while the latter to sub-proton scale. However, some works have highlighted an underestimation of the current density via the curlometer technique with respect to the current computed directly from the velocity distribution functions, measured at sub-proton scales resolution with MMS. In this paper we explore the limit of the curlometer technique studying synthetic data sets associated to a cluster of four artificial satellites allowed to fly in a static turbulent field, spanning a wide range of relative separation. This study tries to address the relative importance of measuring plasma moments at very high resolution from a single spacecraft with respect to the multi-spacecraft missions in the current density evaluation.