cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A sufficient integral condition for local regularity of solutions to the surface growth model
Creators: name: Ożański, Wojciech S.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: The surface growth model, $u_t + u_{xxxx} + \partial_{xx} u_x^2 =0$, is a one-dimensional fourth order equation, which shares a number of striking similarities with the three-dimensional incompressible Navier--Stokes equations, including the results regarding existence and uniqueness of solutions and the partial regularity theory. Here we show that a weak solution of this equation is smooth on a space-time cylinder $Q$ if the Serrin condition $u_x\in L^{q'}L^q (Q)$ is satisfied, where $q,q'\in [1,\infty ]$ are such that either $1/q+4/q'<1$ or $1/q+4/q'=1$, $q'<\infty$.
description: 18 pages
An Experiment in Ethiopia:
Creators: name: Bruno, Karl
Publisher: name: Leipziger Universitätsverlag
Year: 2017

description: Der Beitrag untersucht ein von Schweden geleitetes Projekt im Bereich der integrierten ländlichen Entwicklung, das Chilalo Agricultural Development Unit (CADU) in der Provinz Arussi in Äthopien. Entworfen von einer Gruppe von Experten des Agricultural College of Sweden bildete CADU den ersten größeren schwedischen Versuch, agronomisches Wissen im Kontext von Entwicklungszusammenarbeit in den globalen Süden zu transferieren. Mit Hilfe eines Maßnahmenbündels sollte sozio-ökonomische Entwicklung ermöglicht und beschleunigt werden. Im Mittelpunkt standen landwirtschaftliche Experimente, um die Produktivität von Kleinbauern zu steigern. Entwicklungsstrategien und die entsprechenden Technologien waren stark von der wissenschaftlich-technischen Tradition des Agricultural College geprägt. Einerseits berücksichtigten sie in erheblichem Maße die Speziika der jeweiligen lokalen Landwirtschaft. Andererseits blendeten sie soziale Faktoren weitgehend aus. Die Berücksichtigung lokaler Gegebenheiten machte das Projekt zu einem der wenigen Projekte im Rahmen der Grünen Revolution in Afrika, die erfolgreich waren. Die Vernachlässigung sozialer Faktoren trug jedoch dazu bei, dass Bauern das Projekt nicht uneingeschränkt begrüßten, und dass insgesamt die soziale Ungleichheit im Projektgebiet wuchs. Als Folge des Fokus auf arme Bauern entwickelte sich CADU zu einem politisch stark umstrittenen Projekt. Im Kontext der zunehmenden Spannungen im spät-imperialen Äthiopien wurde es zu einem aktiven Akteur in den ländlichen Konlikten, die der Revolution von 974 vorausgingen.
description: Comparativ, Vol 27 No 2 (2017): Rural Development in the Twentieth Century: International Perspectives
Topological pumping of photons in nonlinear resonator arrays
Creators: name: Tangpanitanon, Jirawat
name: Bastidas, Victor M.
name: Al-Assam, Sarah
name: Roushan, Pedram
name: Jaksch, Dieter
name: Angelakis, Dimitris G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show how to implement topological or Thouless pumping of interacting photons in one dimensional nonlinear resonator arrays, by simply modulating the frequency of the resonators periodically in space and time. The interplay between interactions and the adiabatic modulations enables robust transport of Fock states with few photons per site. We analyze the transport mechanism via an effective analytic model and study its topological properties and its protection to noise. We conclude by a detailed study of an implementation with existing circuit QED architectures.
description: 5 pages, 4 figures, and Supplemental Material. Comments are welcome
Rural Development and Changing Labour Relations in Italy and Spain in the 1950s and 1960s
Creators: name: Sciacchitano, Grazia
Publisher: name: Leipziger Universitätsverlag
Year: 2017

description: Der Aufsatz beschäftigt sich mit der Politik gegenüber ländlichen Räumen im Italien und Spanien der 950er und 960er Jahre. Er untersucht die sozio-ökonomischen Folgen dieser Politik am Beispiel Siziliens und Andalusiens. Der Vergleich der beiden ländlichen Räume verweist auf ein gemeinsames Entwicklungsmodell im südlichen Europa, in dem die Steigerung landwirtschaftlicher Produktion und die Verringerung der in der Landwirtschaft tätigen Arbeitskräfte im Mittelpunkt standen. Siedlungsprojekte spielten demgegenüber nur eine vergleichsweise geringe Rolle. Der Beitrag rekurriert auf Datenmaterial, das den Grad der Beschäftigungen in der Landwirtschaft zwischen 950 und 970 widerspiegelt. Er zeigt, dass zwar immer weniger Menschen insgesamt in der Landwirtschaft beschäftigt waren, die Zahl von Landarbeitern, die nicht über Grundbesitz verfügten, aber zunahm.
description: Comparativ, Vol 27 No 2 (2017): Rural Development in the Twentieth Century: International Perspectives
Antiferroelectric instability in kagome francisites Cu$_3$Bi(SeO$_3$)$_2$O$_2$X (X = Cl, Br)
Creators: name: Prishchenko, Danil A.
name: Tsirlin, Alexander A.
name: Tsurkan, Vladimir
name: Loidl, Alois
name: Jesche, Anton
name: Mazurenko, Vladimir G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Density-functional calculations of lattice dynamics and high-resolution synchrotron powder diffraction uncover antiferroelectric distortion in the kagome francisite Cu$_3$Bi(SeO$_3$)$_2$O$_2$Cl below 115K. Its Br-containing analogue is stable in the room-temperature crystal structure down to at least 10K, although the Br compound is on the verge of a similar antiferroelectric instability and reveals local displacements of Cu and Br atoms. The I-containing compound is stable in its room-temperature structure according to density-functional calculations. We show that the distortion involves cooperative displacements of Cu and Cl atoms, and originates from the optimization of interatomic distances for weakly bonded halogen atoms. The distortion introduces a tangible deformation of the kagome spin lattice and may be responsible for the reduced net magnetization of the Cl compound compared to the Br one. The polar structure of Cu$_3$Bi(SeO$_3$)$_2$O$_2$Cl is only slightly higher in energy than the non-polar antiferroelectric structure, but no convincing evidence of its formation could be obtained.
description: 11 pages, 7 figures
Emergent metallicity at the grain boundaries of higher-order topological insulators
Creators: name: Salib, Daniel J.
name: Juričić, Vladimir
name: Roy, Bitan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Topological lattice defects, such as dislocations and grain boundaries (GBs), are ubiquitously present in the bulk of quantum materials and externally tunable in metamaterials. In terms of robust modes, localized near the defect cores, they are instrumental in identifying topological crystals, featuring the hallmark band inversion at a finite momentum (translationally active type). Here we show that GB superlattices in both two-dimensional and three-dimensional translationally active higher-order topological insulators harbor a myriad of dispersive modes that are typically placed at finite energies, but always well-separated from the bulk states. However, when the Burgers vector of the constituting edge dislocations points toward the gapless corners or hinges, both second-order and third-order topological insulators accommodate self-organized emergent topological metals near the zero energy (half-filling) in the GB mini Brillouin zone. We discuss possible material platforms where our proposed scenarios can be realized through the band-structure and defect engineering.
description: Published version: 7 Pages, 4 Figures (Supplementary Information as Ancillary file)
Doctrines and Practices of Agrarian Development:
Creators: name: Frey, Marc
Publisher: name: Leipziger Universitätsverlag
Year: 2017

description: Der Beitrag handelt von einem großen Bewässerungsprojekt im Binnendelta des Niger, dem Oice du Niger. Geplant nach dem Ersten Weltkrieg und gegründet 92 ist es eines der ältesten Entwicklungsprojekte im ländlichen Raum, die es gibt. Vom kolonialen Paradigma der Produktion über die Vision einer sozialistischen ländlichen Wirtschaft bis hin zu den liberalen Ansätzen der Zeit nach 980 haben exogene Entwicklungsdoktrinen seine Geschichte maßgeblich geprägt. Der Aufsatz argumentiert, dass das Oice du Niger zwar grundlegendem institutionellem und sozialem Wandel unterlag. Über seine lange Geschichte hinweg sind jedoch auch Kontinuitäten sichtbar, wie etwa das Phänomen der strukturellen Gewalt, die Betonung von Produktivität und hierarchische Entscheidungsprozesse, die die Möglichkeiten der Siedler einschränken.
description: Comparativ, Vol 27 No 2 (2017): Rural Development in the Twentieth Century: International Perspectives
Weak solutions to the Navier-Stokes inequality with arbitrary energy profiles
Creators: name: Ożański, Wojciech S.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In a recent paper, Buckmaster & Vicol (arXiv:1709.10033) used the method of convex integration to construct weak solutions $u$ to the 3D incompressible Navier-Stokes equations such that $\| u(t) \|_{L^2} =e(t)$ for a given non-negative and smooth energy profile $e: [0,T]\to \mathbb{R}$. However, it is not known whether it is possible to extend this method to construct nonunique suitable weak solutions (that is weak solutions satisfying the strong energy inequality (SEI) and the local energy inequality (LEI)), Leray-Hopf weak solutions (that is weak solutions satisfying the SEI), or at least to exclude energy profiles that are not nonincreasing. In this paper we are concerned with weak solutions to the Navier-Stokes inequality on $\mathbb{R}^3$, that is vector fields that satisfy both the SEI and the LEI (but not necessarily solve the Navier-Stokes equations). Given $T>0$ and a nonincreasing energy profile $e\colon [0,T] \to [0,\infty )$ we construct weak solution to the Navier-Stokes inequality that are localised in space and whose energy profile $\| u(t)\|_{L^2 (\mathbb{R}^3 )}$ stays arbitrarily close to $e(t)$ for all $t\in [0,T]$. Our method applies only to nonincreasing energy profiles. The relevance of such solutions is that, despite not satisfying the Navier-Stokes equations, they satisfy the partial regularity theory of Caffarelli, Kohn & Nirenberg (Comm. Pure Appl. Math., 1982). In fact, Scheffer's constructions of weak solutions to the Navier-Stokes inequality with blow-ups (Comm. Math. Phys., 1985 & 1987) show that the Caffarelli, Kohn & Nirenberg's theory is sharp for such solutions. Our approach gives an indication of a number of ideas used by Scheffer. Moreover, it can be used to obtain a stronger result than Scheffer's. Namely, we obtain weak solutions to the Navier-Stokes inequality with both blow-up and a prescribed energy profile.
description: 26 pages, 4 figures. arXiv admin note: text overlap with arXiv:1709.00602
Filling-enforced Kondo semimetals in two-dimensional non-symmorphic crystals
Creators: name: Pixley, J. H.
name: Lee, SungBin
name: Brandom, B.
name: Parameswaran, S. A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the competition between Kondo screening and frustrated magnetism on the non-symmorphic Shastry-Sutherland Kondo lattice at a filling of two conduction electrons per unit cell. A previous analysis of this model identified a set of gapless partially Kondo screened phases intermediate between the Kondo-destroyed paramagnet and the heavy Fermi liquid. Based on crystal symmetries, we argue that (i)~both the paramagnet and the heavy Fermi liquid are {\it semimetals} protected by a glide symmetry; and (ii)~partial Kondo screening breaks the symmetry, removing this protection and allowing the partially-Kondo-screened phase to be deformed into a Kondo insulator via a Lifshitz transition. We confirm these results using large-$N$ mean field theory and then use non-perturbative arguments to derive a generalized Luttinger sum rule constraining the phase structure of 2D non-symmorphic Kondo lattices beyond the mean-field limit.
description: 5 pages, 3 figures + Supplemental Material 2 pages
Calculating course units according to the Bologna system
Creators: name: I.Al-Mosawi, Ali
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 399999
subject: Other education not elsewhere classified

description: Each educational system in a particular country or entity has a specificity that distinguishes it from others, and this specificity qualifies it to be an experience to be emulated in other countries that aspire to improve their educational system or replace it completely. An example of such successful educational systems is the European educational system, or as it is referred to as the Bologna process, whose goal was to raise the quality of education in the countries of the European Union and bring it almost to a similar level. This system or track has been approved for implementation in Iraqi universities now, and to facilitate the process of understanding and realizing this system, I will present in this report a simplified explanation for calculating the units in it.
An Anti-Colonial Empire?
Creators: name: Wagner, Florian
Publisher: name: Leipziger Universitätsverlag
Year: 2017

description: Der Erste Weltkrieg beseitigte nicht nur Deutschlands Status als Kolonialmacht. Er bewegte auch die deutsche Regierung dazu, mit antikolonialen Bewegungen in der ganzen Welt zu kooperieren, um die Imperien ihrer Kriegsgegner zu destabilisieren. Es nimmt darum nicht Wunder, dass antikoloniale Intellektuelle nach dem Krieg ihre Hoffnungen auf das scheinbar dekolonisierte und potenziell antikoloniale Deutschland setzten. Diese Erwartung gab der Weimarer Republik die Gelegenheit, sich als antikoloniale Macht zu etablieren und gleichzeitig ihren indirekten Einfluss auf die nicht-europäische Welt auszudehnen. Dieser Artikel fragt, warum das Deutschland der Zwischenkriegszeit das Angebot ablehnte, sich als „antikoloniales Imperium“ bei den Siegern von 1919 zu revanchieren. Entgegen gängigen Interpretationen wird dabei gezeigt, dass selbst Revanchisten darauf vertrauten, weiterhin eine europäische Kolonialmacht zu bleiben. Zudem verhinderten rassistische Einbürgerungsgesetze einen praktischen Wandel Deutschlands zur „antikolonialen Metropole“.
description: Comparativ, Vol 26 No 6 (2016): Ideas of Empire after the First World War: Redefining Identity and Citizenship in Colonial Empires
Two-instanton approximation to the Coulomb blockade problem
Creators: name: Burmistrov, I. S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We develop the two-instanton approximation to the current-voltage characteristic of a single electron transistor within the Ambegaokar-Eckern-Schön model. We determine the temperature and gate voltage dependence of the Coulomb blockade oscillations of the conductance and the effective charge. We find that a small (in comparison with the charging energy) bias voltage leads to significant suppression of the Coulomb blockade oscillations and to appearance of the bias-dependent phase shift.
Reionization and the ISM/Stellar Origins with JWST and ALMA (RIOJA): The core of the highest redshift galaxy overdensity at $z = 7.88$ confirmed by NIRSpec/JWST
Creators: name: Hashimoto, Takuya
name: Álvarez-Márquez, Javier
name: Fudamoto, Yoshinobu
name: Colina, Luis
name: Inoue, Akio K.
name: Nakazato, Yurina
name: Ceverino, Daniel
name: Yoshida, Naoki
name: Costantin, Luca
name: Sugahara, Yuma
name: Gómez, Alejandro Crespo
name: Blanco-Prieto, Carmen
name: Mawatari, Ken
name: Arribas, Santiago
name: Marques-Chaves, Rui
name: Pereira-Santaella, Miguel
name: Bakx, Tom J. L. C.
name: Hagimoto, Masato
name: Hashigaya, Takeshi
name: Matsuo, Hiroshi
name: Tamura, Yoichi
name: Usui, Mitsutaka
name: Ren, Yi W.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The protoclusters in the epoch of reionization, traced by galaxies overdensity regions, are ideal laboratories for studying the process of stellar assembly and cosmic reionization. We present the spectroscopic confirmation of the core of the most distant protocluster at $z = 7.88$, A2744-z7p9OD, with the James Webb Space Telescope NIRSpec integral field unit spectroscopy. The core region includes as many as 4 galaxies detected in [OIII] 4960 Å and 5008 Å in a small area of $\sim 3\arcsec \times 3\arcsec$, corresponding to $\sim$ 11 kpc $\times$ 11 kpc, after the lensing magnification correction. Three member galaxies are also tentatively detected in dust continuum in Atacama Large Millimeter/submillimeter Array Band 6, which is consistent with their red ultraviolet continuum slopes, $β\sim -1.3$. The member galaxies have stellar masses in the range of log($M_{*}/M_{\rm \odot}$) $\sim 7.6-9.2$ and star formation rates of $\sim 3-50$ $M_{\rm \odot}$ yr$^{-1}$, showing a diversity in their properties. FirstLight cosmological simulations reproduce the physical properties of the member galaxies including the stellar mass, [OIII] luminosity, and dust-to-stellar mass ratio, and predict that the member galaxies are on the verge of merging in a few to several tens Myr to become a large galaxy with $M_{\rm *}\sim 6\times10^{9} M_{\rm \odot}$. The presence of a multiple merger and evolved galaxies in the core region of A2744-z7p9OD indicates that environmental effects are already at work 650 Myr after the Big Bang.
description: 12 pages, 4 figures, 1 table, published in The Astrophysical Journal Letters
Role of direct exchange and Dzyaloshinskii-Moriya interactions in magnetic properties of graphene derivatives: C$_2$F and C$_2$H
Creators: name: Mazurenko, V. V.
name: Rudenko, A. N.
name: Nikolaev, S. A.
name: Medvedeva, D. S.
name: Lichtenstein, A. I.
name: Katsnelson, M. I.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: According to the Lieb's theorem the ferromagnetic interaction in graphene-based materials with bipartite lattice is a result of disbalance between the number of sites available for $p_z$ electrons in different sublattices. Here, we report on another mechanism of the ferromagnetism in functionalized graphene that is the direct exchange interaction between spin orbitals. By the example of the single-side semihydrogenated (C$_2$H) and semifluorinated (C$_2$F) graphene we show that such a coupling can partially or even fully compensate antiferromagnetic character of indirect exchange interactions reported earlier [Phys. Rev. B {\bf 88}, 081405(R) (2013)]. As a result, C$_2$H is found to be a two-dimensional material with the isotropic ferromagnetic interaction and negligibly small magnetic anisotropy, which prevents the formation of the long-range magnetic order at finite temperature in accordance with the Mermin-Wagner theorem. This gives a rare example of a system where direct exchange interactions play a crucial role in determining a magnetic structure. In turn, C$_2$F is found to be at the threshold of the antiferromagnetic-ferromagnetic instability, which in combination with the Dzyaloshinskii-Moriya interaction can lead to a skyrmion state.
description: 10 pages
Proposal that interpretation of field emission current-voltage characteristics should be treated as a specialized form of electrical engineering
Creators: name: Forbes, Richard G.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: This article proposes that we should think differently about predicting and interpreting measured field electron emission (FE) current-voltage [I(V)] characteristics. It is commonly assumed that I(V) data interpretation is a problem in emission physics and related electrostatics. Many experimentalists then apply Fowler-Nordheim plot methodology, developed in 1929. However, with modern emitting materials this 90-year-old interpretation methodology often fails (maybe in nearly 50% of cases), and yields spurious values for characterization parameters, particularly field enhancement factors. This has generated an unreliable literature, and validity checks on experimental I(V) data are nearly always needed before use. A new check, supplementing existing checks, is described. Twelve different "system complications" that, acting singly or in combinations, can cause validity-check failure are identified. A top-level path forwards from this unsatisfactory situation is proposed. The term "field electron emission system (FE system)" is defined to include all aspects of an experimental system that affect the measured I(V) characteristics. The analysis of FE systems should now be regarded as a specialized form of electronic/electrical engineering, provisionally called "FE Systems Engineering". In this approach, the I(V) relationship is split: (a) the current is expressed as a function I(F_C) of the local surface-field magnitude F_C at some defined emitter surface location "C"; and (b) the relationship between F_C and measured voltage V is expressed and determined separately. Determining I(F_C) is mostly a problem in emission physics; determining the relationship (F_C)(V) depends on system electrostatics and (for systems failing a validity check) on other aspects of FE Systems Engineering. The scope of FE Systems Engineering, and some related research implications and problems, are outlined.
description: 21 pages, 0 figures. Full write-up of conference presentation. Submitted to Journal of Vacuum Science and Technology. Currently under revision after review
Fractured Empire:
Creators: name: Gorman, Dan
Publisher: name: Leipziger Universitätsverlag
Year: 2017

description: Der Erste Weltkrieg brachte Bürger aus Großbritannien, und Untertanen aus den britischen Dominions und dem Kolonialreich zusammen, sowohl auf dem Schlachtfeld als auch hinter der Kampffont. Er hat sie auch unter einem historischen Rahmen vereinigt, was in den Nachkriegsjahren zu einer intensiven Beschäftigung mit den rassischen und legalen Widersprüchen der Staatsbürgerschaft des Britischen Empire führte. Der Krieg verursachte eine engere Zusammenarbeit zwischen Großbritannien und den Dominions an Fragen von gemeinsamem Interesse, vertieft durch eine gemeinsame Loyalität zum britischen Empire, eine Verbundenheit der weißen Rassen, und eine gemeinsame Kriegserfahrung. Immerhin verlangten die Politiker aus den Dominions größere Autonomie auf Grund derer Kriegsleistungen und Nationalisten in den Kolonien setzten sich für mehr Bürgerechte für ihre Wählerschaft ein. Dieser Artikel untersucht die rhetorischen, rechtlichen, moralischen, und materiellen Aspekte der Staatsbürgerschaft des Britischen Empire während des Ersten Weltkriegs und in den Jahren danach. Die verschiedenen Formen der Loyalität zum Britischen Empire und der koloniale Nationalismus, die die Untertanen des Empire zur Teilnahme an Großbritanniens globalen Krieg motivierten, werden erläutert. Auch untersucht wird wie der Krieg größere Zusammenarbeit sowie mehr Konflikte innerhalb des Britischen Empire verursachte, und die Entstehung in der Zwischenkriegszeit von antikolonialen Loyalitäten sowie weißen Loyalitäten zum Britischen Empire.
description: Comparativ, Vol 26 No 6 (2016): Ideas of Empire after the First World War: Redefining Identity and Citizenship in Colonial Empires
Detecting the Stimulated Decay of Axions at Radio Frequencies
Creators: name: Caputo, A.
name: Regis, M.
name: Taoso, M.
name: Witte, S. J.
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Assuming axion-like particles account for the entirety of the dark matter in the Universe, we study the possibility of detecting their decay into photons at radio frequencies. We discuss different astrophysical targets, such as dwarf spheroidal galaxies, the Galactic Center and halo, and galaxy clusters. The presence of an ambient radiation field leads to a stimulated enhancement of the decay rate; depending on the environment and the mass of the axion, the effect of stimulated emission may amplify the photon flux by serval orders of magnitude. For axion-photon couplings allowed by astrophysical and laboratory constraints(and possibly favored by stellar cooling), we find the signal to be within the reach of next-generation radio telescopes such as the Square Kilometer Array.
description: Minor changes, references added, matches published version
Tricritical Dicke model with and without dissipation
Creators: name: Padilla, Diego Fallas
name: Pu, Han
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Light-matter interacting systems involving multi-level atoms are appealing platforms for testing equilibrium and dynamical phenomena. Here, we explore a tricritical Dicke model, where an ensemble of three-level systems interacts with a single light mode, through two different approaches: a generalized Holstein-Primakoff map, and a treatment using the Gell-Mann matrices. Both methods are found to be equivalent in the thermodynamic limit of an infinite number of atoms. In equilibrium, the system exhibits a rich phase diagram where both continuous and discrete symmetries can be spontaneously broken. We characterize all the different types of symmetries according to their scaling behaviors. Far from the thermodynamic limit, considering just a few tens of atoms, the system already exhibits features that could help characterize both second and first-order transitions in a potential experiment. Importantly, we show that the tricritical behavior is preserved when dissipation is taken into account, moreover, the system develops a steady-state phase diagram with various regions of bistability, all of them converging at the tricritical point. Having multiple stable normal and superradiant phases opens prospective avenues for engineering interesting steady states by a clever choice of initial states and/or parameter quenching.
description: 13 pages, 8 figures
Probing the gamma-ray variability in 3C279 using broadband observations
Creators: name: Rani, B.
name: Krichbaum, T. P.
name: Lee, S. -S.
name: Sokolovsky, K.
name: Kang, S.
name: Byun, D. -Y.
name: Mosunova, D.
name: Zensus, J. A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present the results of a broadband radio-to-GeV observing campaign organized to get a better understanding of the radiation processes responsible for the $γ$-ray flares observed in 3C 279. The total intensity and polarization observations of the source were carried out between December 28, 2013 and January 03, 2014 using the Fermi-LAT, Swift-XRT, Swift-UVOT, and KVN telescopes. A prominent flare observed in the optical/near-UV passbands was found to be correlated with a concurrent $γ$-ray flare at a confidence level $>$95$\%$, which suggests a co-spatial origin of the two. Moreover, the flaring activity in the two regimes was accompanied by no significant spectral variations. A peak in the X-ray light curve coincides with the peaks of the fractional polarization curves at 43 and 86 GHz radio bands. No prominent variation was noticed for the total intensity and the electric vector position angle (EVPA) observations at radio bands during this period. We noticed a possible hint of steepening of the radio spectrum with an increase in percentage polarization, which suggests that the radio polarization variations could be simply due to a spectral change. In a simple scenario, the correlated optical/$γ$-ray flares could be caused by the same population of emitting particles. The coincidence of the increase in radio polarization with the X-ray flux supports the picture that X-rays are produced via inverse-Compton scattering of radio photons. The observed fractional variability for the $γ$-ray flare $\sim$0.23 does not exceed that in the optical regime, which is inconsistent with what we usually observe for 3C 279; it could be due to different dependencies of the magnetic field and the external radiation field energy density profiles along the jet.
description: 10 pages, 8 figures, accepted for publication in MNRAS
Introduction.
Creators: name: Lorenzini, Sara
Publisher: name: Leipziger Universitätsverlag
Year: 2017

description: Die Einleitung bietet einen Überblick über die Entwicklung der Kolonialreiche nach dem Ersten Weltkrieg. Sie legt dar, wie in den 1920er Jahren das koloniale Ideal neu formuliert wurde. Durch die Schilderung der Folgen des Weltkriege in Afrika und im Nahen Osten deckt sie auf, wie der Friede von Paris 1919 und der daraus entstehende Völkerbund neue koloniale Machtstrukturen formalisierten. Anhand von britischen, französischen, deutschen und italienischen Fallbeispielen wird deutlich gemacht, dass die Politik der Nachkriegszeit, anstatt Emanzipation zu fördern, Konzepte von Rasse, Geschlecht und Staatsangehörigkeit verwendete, um neue konservative Strategien für den Erhalt imperialer Einheit zu artikulieren und institutionalisieren.
description: Comparativ, Vol 26 No 6 (2016): Ideas of Empire after the First World War: Redefining Identity and Citizenship in Colonial Empires
A novel unbinned model-independent method to measure the CKM angle $γ$ in $B^{\pm} \to DK^{\pm}$ decays with optimised precision
Creators: name: Lane, Jake
name: Gersabeck, Evelina
name: Rademacker, Jonas
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We present a novel unbinned method to combine $B^{\pm} \to DK^{\pm}$ and charm threshold data for the amplitude-model unbiased measurement of the CKM angle gamma in cases where the D meson decays to a three-body final state. The new unbinned approach avoids any kind of integration over the D Dalitz plot, to make optimal use the available information. We verify the method with simulated signal data where the D decays to $K_S π^+ π^-$. Using realistic sample sizes, we find that the new method reaches the statistical precision on gamma of an unbinned model-dependent fit, i.e. as good as possible and better than the widely used model-independent binned approach, without suffering from biases induced by a mis-modeled D decay amplitude.
Do Circumnuclear Dense Gas Disks Drive Mass Accretion onto Supermassive Black Holes?
Creators: name: Izumi, Takuma
name: Kawakatu, Nozomu
name: Kohno, Kotaro
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a positive correlation between the mass of dense molecular gas ($M_{\rm dense}$) of $\sim 100$ pc scale circumnuclear disks (CNDs) and the black hole mass accretion rate ($\dot{M}_{\rm BH}$) in total 10 Seyfert galaxies, based on data compiled from the literature and an archive (median aperture $θ_{\rm med}$ = 220 pc). A typical $M_{\rm dense}$ of CNDs is 10$^{7-8}$ $M_\odot$, estimated from the luminosity of the dense gas tracer, the HCN($1-0$) emission line. Because dense molecular gas is the site of star formation, this correlation is virtually equivalent to the one between nuclear star formation rate and $\dot{M}_{\rm BH}$ revealed previously. Moreover, the $M_{\rm dense}-\dot{M}_{\rm BH}$ correlation was tighter for CND-scale gas than for the gas on kpc or larger scales. This indicates that CNDs likely play an important role in fueling black holes, whereas $>$kpc scale gas does not. To demonstrate a possible approach for studying the CND-scale accretion process with the Atacama Large Millimeter/submillimeter Array (ALMA), we used a mass accretion model where angular momentum loss due to supernova explosions is vital. Based on the model prediction, we suggest that only the partial fraction of the mass accreted from the CND ($\dot{M}_{\rm acc}$) is consumed as $\dot{M}_{\rm BH}$. However, $\dot{M}_{\rm acc}$ agrees well with the total nuclear mass flow rate (i.e., $\dot{M}_{\rm BH}$ + outflow rate). Although these results are still tentative with large uncertainties, they support the view that star formation in CNDs can drive mass accretion onto supermassive black holes in Seyfert galaxies.
description: Accepted for publication in ApJ; 17 pages (including 1 page appendix), 8 figures, 4 tables; Comments welcome!
Deep observations of the Super-CLASS super-cluster at 325 MHz with the GMRT: the low-frequency source catalogue
Creators: name: Riseley, C. J.
name: Scaife, A. M. M.
name: Hales, C. A.
name: Harrison, I.
name: Birkinshaw, M.
name: Battye, R. A.
name: Beswick, R. J.
name: Brown, M. L.
name: Casey, C. M.
name: Chapman, S. C.
name: Demetroullas, C.
name: Hung, C. -L.
name: Jackson, N. J.
name: Muxlow, T.
name: Watson, B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present the results of 325 MHz GMRT observations of a super-cluster field, known to contain five Abell clusters at redshift $z \sim 0.2$. We achieve a nominal sensitivity of $34\,μ$Jy beam$^{-1}$ toward the phase centre. We compile a catalogue of 3257 sources with flux densities in the range $183\,μ\rm{Jy}\,-\,1.5\,\rm{Jy}$ within the entire $\sim 6.5$ square degree field of view. Subsequently, we use available survey data at other frequencies to derive the spectral index distribution for a sub-sample of these sources, recovering two distinct populations -- a dominant population which exhibit spectral index trends typical of steep-spectrum synchrotron emission, and a smaller population of sources with typically flat or rising spectra. We identify a number of sources with ultra-steep spectra or rising spectra for further analysis, finding two candidate high-redshift radio galaxies and three gigahertz-peaked-spectrum radio sources. Finally, we derive the Euclidean-normalised differential source counts using the catalogue compiled in this work, for sources with flux densities in excess of $223 \, μ$Jy. Our differential source counts are consistent with both previous observations at this frequency and models of the low-frequency source population. These represent the deepest source counts yet derived at 325 MHz. Our source counts exhibit the well-known flattening at mJy flux densities, consistent with an emerging population of star-forming galaxies; we also find marginal evidence of a downturn at flux densities below $308 \, μ$Jy, a feature so far only seen at 1.4 GHz.
description: 25 pages, 18 figures, 10 tables. Accepted for publication in MNRAS
Novemberpogrom 1938 – Vertreibung, Attentat, Terror.
Creators: name: Gross, Raphael
Publisher: name: Leipziger Universitätsverlag
Year: 2016

description: On November 7, 1938 Herschel Grynszpan, a young Jewish refugee, shot and killed Ernst vom Rath, a German diplomat in Paris. The Nazi regime took this assassination as a pretext for unleashing extreme violence against hundreds of thousands of German Jews, their dwellings, shops, and synagogues, a process that culminated in the so-called ‘Reichskristallnacht’ of November 9, 1938. Grynszpan belonged to a Jewish family from Hanover that had been deported to Poland by the Nazi authorities days before - together with some 15,000 to 17,000 other German Jews. The article offers a detailed account of the situation stateless Jews faced at the end of the 1930s, in the context of a growing refugee crisis caused by Nazi racial policies. The article also describes Herschel Grynszpan’s ordeal in French and German custody and the postwar European aftermath of his case.
description: Comparativ, Vol 26 No 1 (2016): Zwangsmigration im Europa der Moderne. Nationale Ursachen und transnationale Wirkungen
Higher-order recoil corrections for triplet states of the helium atom
Creators: name: Patkos, V.
name: Yerokhin, V. A.
name: Pachucki, K.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: FOS: Physical sciences

description: Nuclear recoil corrections of order $α^6\,m^2/M$ are calculated for the lowest-lying triplet states of the helium atom. It improves the theoretical prediction for the isotope shift of the $2^3S-2^3P$ transition energy and influences the determination of the ${}^3\textrm{He}-{}^4\textrm{He}$ nuclear charge radii difference. This calculation is a step forward on the way towards the direct determination of the charge radius of the helium nucleus from spectroscopic measurements.
description: 45 pages
An embedded-hybridized discontinuous Galerkin method for the coupled Stokes-Darcy system
Creators: name: Cesmelioglu, Aycil
name: Rhebergen, Sander
name: Wells, Garth N.
Publisher: name: arXiv
Year: 2019
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65N12, 65N15, 65N30, 76D07, 76S99

description: We introduce an embedded-hybridized discontinuous Galerkin (EDG-HDG) method for the coupled Stokes-Darcy system. This EDG-HDG method is a pointwise mass-conserving discretization resulting in a divergence-conforming velocity field on the whole domain. In the proposed scheme, coupling between the Stokes and Darcy domains is achieved naturally through the EDG-HDG facet variables. \emph{A priori} error analysis shows optimal convergence rates, and that the velocity error does not depend on the pressure. The error analysis is verified through numerical examples on unstructured grids for different orders of polynomial approximation.
Three-$α$ configurations of the second $J^π=2^+$ state in $^{12}$C
Creators: name: Moriya, H.
name: Horiuchi, W.
name: Casal, J.
name: Fortunato, L.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We investigate geometric configurations of $α$ ($^4$He nucleus) clusters in the second $J^π=2^+$ state of $^{12}$C, which has been discussed as a rotational band member of the second $0^+$ state, the Hoyle state. The ground and excited $0^+$ and $2^+$ states are described by a three-$α$ cluster model. The three-body Schrödinger equation with orthogonality conditions is accurately solved by the stochastic variational method with correlated Gaussian basis functions. To analyse the structure of these resonant states in a convenient form, we introduce a confining potential. The two-body density distributions together with the spectroscopic information clarify the structure of these states. We find that main configurations of both the second $0^+$ and $2^+$ states are acute-angled triangle shapes originating from the $^8$Be($0^+$)$+α$ configuration. However, the $^8$Be$+α$ components in the second $2^+$ state become approximately 2/3 because the 8Be subsystem is hard to excite, indicating that the state is not an ideal rigid rotational band member of the Hoyle state.
description: 7 pages, 3 figures
Higgsed Chromo-Natural Inflation
Creators: name: Adshead, Peter
name: Martinec, Emil
name: Sfakianakis, Evangelos I.
name: Wyman, Mark
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We demonstrate that Chromo-Natural Inflation can be made consistent with observational data if the SU(2) gauge symmetry is spontaneously broken. Working in the Stueckelberg limit, we show that isocurvature is negligible, and the resulting adiabatic fluctuations can match current observational constraints. Observable levels of chirally-polarized gravitational radiation ($r\sim 10^{-3}$) can be produced while the evolution of all background fields is sub-Planckian. The gravitational wave spectrum is amplified via linear mixing with the gauge field fluctuations, and its amplitude is not simply set by the Hubble rate during inflation. This allows observable gravitational waves to be produced for an inflationary energy scale below the GUT scale. The tilt of the resulting gravitational wave spectrum can be either blue or red.
description: 34 +12 pages, 9 figures
„Völkische Flurbereinigung“ –
Creators: name: Wildt, Michael
Publisher: name: Leipziger Universitätsverlag
Year: 2016

description: This essay focuses on the Nazi ethnic and racist policy in Eastern and Western Europe. From the beginning on the Nazi plans for the war against Poland intended to transform huge parts of Polish territory into areas of German settlement – the realization of the Nazi project of Lebensraum in Eastern Europe. Germanization of these areas meant racist differentiation of the local people and different practices of inclusion and exclusion, whether they were classified as German or of German origin, as friendly or hostile Poles or as Jewish. These racist measures had been practiced in Western Europe, too. The context of Nazi ethnic politics was a conceptual shift from nation to Volk, from demos to ethnos since the end of nineteenth century. The coincidence of the definition of people not only an ensemble of citizens but as a cultural, ethnic unit and the rise of biology as a dominant pattern of interpreting human nature made ‘biopolicy’ (Foucault) a common political practice not only in Nazi Germany but all over Europe. What made Nazi ethnic politics unique was the unalterable, exclusionary Anti-Semitism which lead to systematic mass murder and the violent eagerness of the Nazi regime to realize its vision of an ethnically structured ‘New Europe’ in which Germans should rule as a superior race.
description: Comparativ, Vol 26 No 1 (2016): Zwangsmigration im Europa der Moderne. Nationale Ursachen und transnationale Wirkungen
Exploring energy landscapes of charge multipoles using constrained density functional theory
Creators: name: Schaufelberger, Luca
name: Merkel, Maximilian E.
name: Tehrani, Aria Mansouri
name: Spaldin, Nicola A.
name: Ederer, Claude
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We present a method to constrain local charge multipoles within density-functional theory. Such multipoles quantify the anisotropy of the local charge distribution around atomic sites and can indicate potential hidden orders. Our method allows selective control of specific multipoles, facilitating a quantitative exploration of the energetic landscape outside of local minima. Thus, it enables a clear distinction between electronically and structurally driven instabilities. We demonstrate the effectiveness of this method by applying it to charge quadrupoles in the prototypical orbitally ordered material KCuF$_3$. We quantify intersite multipole-multipole interactions as well as the energy-lowering related to the formation of an isolated local quadrupole. We also map out the energy as a function of the size of the local quadrupole moment around its local minimum, enabling quantification of multipole fluctuations around their equilibrium value. Finally, we study charge quadrupoles in the solid solution KCu$_{1-x}$Zn$_x$F$_3$ to characterize the behavior across the tetragonal-to-cubic transition. Our method provides a powerful tool for studying symmetry breaking in materials with coupled electronic and structural instabilities and potentially hidden orders.
Relating ordinary and fully simple maps via monotone Hurwitz numbers
Creators: name: Borot, Gaëtan
name: Charbonnier, Séverin
name: Do, Norman
name: Garcia-Failde, Elba
Publisher: name: arXiv
Year: 2019
Subjects: subject: Combinatorics (math.CO)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 05A15, 05A19, 20C30

description: A direct relation between the enumeration of ordinary maps and that of fully simple maps first appeared in the work of the first and last authors. The relation is via monotone Hurwitz numbers and was originally proved using Weingarten calculus for matrix integrals. The goal of this paper is to present two independent proofs that are purely combinatorial and generalise in various directions, such as to the setting of stuffed maps and hypermaps. The main motivation to understand the relation between ordinary and fully simple maps is the fact that it could shed light on fundamental, yet still not well-understood, problems in free probability and topological recursion.
description: 19 pages, 7 figures
Electrocardiogram signal denoising using non-local wavelet transform domain filtering
Creators: name: Yadav, Santosh Kumar
name: Sinha, Rohit
name: Bora, Prabin Kumar
Publisher: name: arXiv
Year: 2016
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: ECG signals are usually corrupted by baseline wander, power-line interference, muscle noise, etc. and numerous methods have been proposed to remove these noises. However, in case of wireless recording of the ECG signal it gets corrupted by the additive white Gaussian noise (AWGN). For the correct diagnosis, removal of AWGN from ECG signals becomes necessary as it affects the all the diagnostic features. The natural signals exhibit correlation among their samples and this property has been exploited in various signal restoration tasks. Motivated by that, in this work we propose a nonlocal wavelet transform domain ECG signal denoising method which exploits the correlations among both local and nonlocal samples of the signal. In the proposed method, the similar blocks of the samples are grouped in a matrix and then denoising is achieved by the shrinkage of its two-dimensional discrete wavelet transform coefficients. The experiments performed on a number of ECG signals show significant quantitative and qualitative improvement in denoising performance over the existing ECG signal denoising methods.