cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Mapping $n$ grid points onto a square forces an arbitrarily large Lipschitz constant
Creators: name: Dymond, Michael
name: Kaluža, Vojtěch
name: Kopecká, Eva
Publisher: name: arXiv
Year: 2017
Subjects: subject: Metric Geometry (math.MG)
subject: Discrete Mathematics (cs.DM)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 51F99, 51M05, 52C99, 26B35, 26B10

description: We prove that the regular $n\times n$ square grid of points in the integer lattice $\mathbb{Z}^{2}$ cannot be recovered from an arbitrary $n^{2}$-element subset of $\mathbb{Z}^{2}$ via a mapping with prescribed Lipschitz constant (independent of $n$). This answers negatively a question of Feige from 2002. Our resolution of Feige's question takes place largely in a continuous setting and is based on some new results for Lipschitz mappings falling into two broad areas of interest, which we study independently. Firstly the present work contains a detailed investigation of Lipschitz regular mappings on Euclidean spaces, with emphasis on their bilipschitz decomposability in a sense comparable to that of the well known result of Jones. Secondly, we build on work of Burago and Kleiner and McMullen on non-realisable densities. We verify the existence, and further prevalence, of strongly non-realisable densities inside spaces of continuous functions.
description: 60 pages (43 pages of the main part, 13 pages of appendices), 10 figures. This is a revised version according to referees' comments. Our version of the proof of the theorem about bilipschitz decomposition of Lipschitz regular mappings was greatly simplified. To appear in GAFA
Die Marsilius-Studien und der kritisch-lebendige Geist der Universität
Creators: name: Riemer, Alexander
Publisher: name: Forum Marsilius-Kolleg
Year: 2022

description: Alexander Riemer (Studierender der Bildungswissenschaft) spricht über seine Erfahrungen als Kommissionsmitglied der Marsilius-Studien.
description: Forum Marsilius-Kolleg, Bd. 22 Nr. 2 (2022): Jahresbericht 2021/22
Disruption of sheetlike structures in Alfvénic turbulence by magnetic reconnection
Creators: name: Mallet, A.
name: Schekochihin, A. A.
name: Chandran, B. D. G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: We propose a mechanism whereby the intense, sheet-like structures naturally formed by dynamically aligning Alfvénic turbulence are destroyed by magnetic reconnection at a scale $\hatλ_{\rm D}$, larger than the dissipation scale predicted by models of intermittent, dynamically aligning turbulence. The reconnection process proceeds in several stages: first, a linear tearing mode with $N$ magnetic islands grows and saturates, and then the $X$-points between these islands collapse into secondary current sheets, which then reconnect until the original structure is destroyed. This effectively imposes an upper limit on the anisotropy of the structures within the perpendicular plane, which means that at scale $\hatλ_{\rm D}$ the turbulent dynamics change: at scales larger than $\hatλ_{\rm D}$, the turbulence exhibits scale-dependent dynamic alignment and a spectral index approximately equal to $-3/2$, while at scales smaller than $\hatλ_{\rm D}$, the turbulent structures undergo a succession of disruptions due to reconnection, limiting dynamic alignment, steepening the effective spectral index and changing the final dissipation scale. The scaling of $\hatλ_{\rm D}$ with the Lundquist (magnetic Reynolds) number $S_{L_\perp}$ depends on the order of the statistics being considered, and on the specific model of intermittency; the transition between the two regimes in the energy spectrum is predicted at approximately $\hatλ_{\rm D} \sim S_{L_\perp}^{-0.6}$. The spectral index below $\hatλ_{\rm D}$ is bounded between $-5/3$ and $-2.3$. The final dissipation scale is at $\hatλ_{η,\infty}\sim S_{L_\perp}^{-3/4}$, the same as the Kolmogorov scale arising in theories of turbulence that do not involve scale-dependent dynamic alignment.
description: 10 pages, 4 figures, published in MNRAS 468 p.4862, replaced with published version
Holography in Lovelock Chern-Simons AdS Gravity
Creators: name: Cvetković, Branislav
name: Miskovic, Olivera
name: Simić, Dejan
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We analyse holographic field theory dual to Lovelock Chern-Simons AdS Gravity in higher dimensions using first order formalism. We first find asymptotic symmetries in the AdS sector showing that they consist of local translations, local Lorentz rotations, dilatations and non-Abelian gauge transformations. Then, we compute $1$-point functions of energy-momentum and spin currents in a dual conformal field theory and write Ward identities. We find that the holographic theory possesses Weyl anomaly and also breaks non-Abelian gauge symmetry at the quantum level.
description: LATEX, 22 pages, no figures; v3 redaction improved, references added; v4 minor revisions
Charge collection properties in an irradiated pixel sensor built in a thick-film HV-SOI process
Creators: name: Hiti, B.
name: Cindro, V.
name: Gorišek, A.
name: Hemperek, T.
name: Kishishita, T.
name: Kramberger, G.
name: Krüger, H.
name: Mandić, I.
name: Mikuž, M.
name: Wermes, N.
name: Zavrtanik, M.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Investigation of HV-CMOS sensors for use as a tracking detector in the ATLAS experiment at the upgraded LHC (HL-LHC) has recently been an active field of research. A potential candidate for a pixel detector built in Silicon-On-Insulator (SOI) technology has already been characterized in terms of radiation hardness to TID (Total Ionizing Dose) and charge collection after a moderate neutron irradiation. In this article we present results of an extensive irradiation hardness study with neutrons up to a fluence of 1x10e16 neq/cm2. Charge collection in a passive pixelated structure was measured by Edge Transient Current Technique (E-TCT). The evolution of the effective space charge concentration was found to be compliant with the acceptor removal model, with the minimum of the space charge concentration being reached after 5x10e14 neq/cm2. An investigation of the in-pixel uniformity of the detector response revealed parasitic charge collection by the epitaxial silicon layer characteristic for the SOI design. The results were backed by a numerical simulation of charge collection in an equivalent detector layout.
description: 14 pages, 10 figures
Fieberkrankheiten von Malaria bis Covid-19
Creators: name: Frischknecht, Friedrich
name: Gänger, Stefanie
name: Schwarz, Ulrich
Publisher: name: Forum Marsilius-Kolleg
Year: 2022

description: Prof. Dr. Friedrich Frischknecht (Infektiologie), Prof. Dr. Stefanie Gänger (Neuere Geschichte) und Prof. Dr. Ulrich Schwarz (Theoretische Biophysik) reflektieren die Ergebnisse ihrer Fellowships innerhalb der Zeitspanne vom 1. Oktober 2021 bis 30. September 2022. Im Rahmen des Projekts „System Fieber: Zur Wirkung von Malaria, Covid-19 und anderen Fieberkrankheiten“ haben sich die drei Fellows mit historischen wie gegenwärtigen Erklärungsansätzen, Präventions- und Heilmethoden für „Fieber“ sowie mit gesellschaftlichen Reaktionen, insbesondere auf epidemisch auftretende „Fieberkrankheiten“ befasst.
description: Forum Marsilius-Kolleg, Bd. 22 Nr. 2 (2022): Jahresbericht 2021/22
The Chronology of Danish Dolmens. Results from 14C Dates on Human Bones
Creators: name: Sjögren, Karl-Göran
name: Fischer, Anders
Publisher: name: Journal of Neolithic Archaeology
Year: 2023

description: The thousands of dolmens and long barrows spread across the Danish landscape are the earliest long-lasting expressions of architectural monumentality in Scandinavia. A series of new AMS dates on human skeletal material from several of them leads to a clarification of the generations-long debate on the relative chronology and typological evolution of this group of monuments. Earthen long barrows were raised from ca. 3700 cal BC. That is at least two centuries later than the arrival of such elements of the Neolithic world as funnel beaker pottery and domestic cattle to the region. The practice of using large stones (megaliths) for burial chambers was present by 3600 BC. Classical Urdolmen were built alongside various types of more complex dolmen chambers during the period ca. 3600–3400 BC, after which passage grave were erected.
description: Journal of Neolithic Archaeology, 25 (2023)
Searching for Gamma-Ray Emission from Reticulum II by Fermi-LAT
Creators: name: Zhao, Yi
name: Bi, Xiao-Jun
name: Yin, Peng-Fei
name: Zhang, Xin-Min
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Recently, many new dwarf spheroidal satellites (dSphs) have been discovered by the Dark Energy Survey (DES). These dSphs are ideal candidates for probing for gamma-ray emissions from dark matter (DM) annihilation. However, no significant signature has been found by the Fermi-LAT dSph observations. In this work, we reanalyze the Fermi-LAT Pass 8 data from the direction of Reticulum II, where a slight excess has been reported by some previous studies. We treat Reticulum II (DES J0335.6-5403) as a spatially extended source, and and that no significant gamma-ray signature is observed. Based on this result, we set upper-limits on the DM annihilation cross section.
description: 7 pages, 5 figures
Frischer Wind für neue Aufgaben
Creators: name: Nüssel, Friederike
name: Boutros, Michael
Publisher: name: Forum Marsilius-Kolleg
Year: 2022

description: Das Direktorium, bestehend aus Prof. Dr. Friederike Nüssel (Systematische Theologie) und Prof. Dr. Michael Boutros (Genomforschung), legt Rechenschaft ab über die Tätigkeit des Marsilius-Kollegs im Zeitraum 1. Oktober 2021 bis 30. September 2022.
description: Forum Marsilius-Kolleg, Bd. 22 Nr. 2 (2022): Jahresbericht 2021/22
Anharmonicity and the isotope effect in superconducting lithium at high pressures: a first-principles approach
Creators: name: Borinaga, Miguel
name: Aseginolaza, Unai
name: Errea, Ion
name: Calandra, Matteo
name: Mauri, Francesco
name: Bergara, Aitor
Publisher: name: arXiv
Year: 2017
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Recent experiments [Schaeffer 2015] have shown that lithium presents an extremely anomalous isotope effect in the 15-25 GPa pressure range. In this article we have calculated the anharmonic phonon dispersion of $\mathrm{^7Li}$ and $\mathrm{^6Li}$ under pressure, their superconducting transition temperatures, and the associated isotope effect. We have found a huge anharmonic renormalization of a transverse acoustic soft mode along $Γ$K in the fcc phase, the expected structure at the pressure range of interest. In fact, the anharmonic correction dynamically stabilizes the fcc phase above 25 GPa. However, we have not found any anomalous scaling of the superconducting temperature with the isotopic mass. Additionally, we have also analyzed whether the two lithium isotopes adopting different structures could explain the observed anomalous behavior. According to our enthalpy calculations including zero-point motion and anharmonicity it would not be possible in a stable regime.
Stellungnahme zur Etablierung der sekundären Forschungsnutzung von Behandlungsdaten in Deutschland
Creators: name: Jungkunz, Martin
name: Köngeter, Anja
name: Spitz, Markus
name: Mehlis, Katja
name: Cornelius, Kai
name: Schickhardt, Christoph
name: Winkler, Eva C.
Publisher: name: Forum Marsilius-Kolleg
Year: 2022

description: Die sekundäre Forschungsnutzung von Behandlungsdaten hat großes Potenzial, biomedizinisches Wissen zu erweitern und die Patientenversorgung zu verbessern. Gleichzeitig sind für eine bessere Ausschöpfung dieses Potenzials diverse Herausforderungen zu bewältigen. Dies gilt insbesondere in Deutschland, wo im Vergleich zu anderen Ländern, wie z.B. Dänemark oder Finnland, die sekundäre Forschungsnutzung von Behandlungsdaten unterentwickelt ist. Die Intensivierung der Nutzung der Daten aus Diagnose und Therapie von Patienten und die Entwicklung der dafür notwendigen Strukturen in Deutschland ist ethisch und politisch geboten: für die Verbesserung der Gesundheitsversorgung durch neue Erkenntnisse, Therapien und Qualitätssicherung. Aus diesem Grund fordern die Autor:innen alle Akteure des Gesundheitssystems, von der Bundes- und den Landesregierungen über die Krankenkassen, Kliniken, Ärzt:innen und Patient:innen dazu auf, einen Beitrag dazu leisten, eine Kultur der sekundären Forschungsnutzung von Behandlungsdaten zu etablieren. Basierend auf den Ergebnissen eines dreijährigen Verbundprojekts beantworten die Autor:innen aus den Bereichen Medizin, Rechtswissenschaften, Ethik und Sozialwissenschaften die Frage was notwendig ist, damit in Deutschland die Daten von Patient:innen systematisch für medizinische Forschung und die Analyse der klinischen Versorgungsqualität verwendet werden können und wirklich auch verwendet werden. Sie nennen zehn zentrale Forderungen und legen eine Liste von 23 Empfehlungen mit konkreten Maßnahmen vor, welche von den genannten Akteuren umgesetzt werden sollten.
description: Forum Marsilius-Kolleg, Bd. 21 (2022): Stellungnahme zur Etablierung der sekundären Forschungsnutzung von Behandlungsdaten in Deutschland
Fractional Virasoro Algebras
Creators: name: La Nave, Gabriele
name: Phillips, Philip
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We show that it is possible to construct a Virasoro algebra as a central extension of the fractional Witt algebra generated by non-local operators of the form, $L_n^a\equiv\left(\frac{\partial f}{\partial z}\right)^a$ where $a\in {\mathbb R}$. The Virasoro algebra is explicitly of the form, \beq [L^a_m,L_n^a]=A_{m,n}L^a_{m+n}+δ_{m,n}h(n)cZ^a \eeq where $c$ is the central charge (not necessarily a constant), $Z^a$ is in the center of the algebra and $h(n)$ obeys a recursion relation related to the coefficients $A_{m,n}$. In fact, we show that all central extensions which respect the special structure developed here which we term a multimodule Lie-Algebra, are of this form. This result provides a mathematical foundation for non-local conformal field theories, in particular recent proposals in condensed matter in which the current has an anomalous dimension.
The lognormal-like statistics of a stochastic squeeze process
Creators: name: Shapira, Dekel
name: Cohen, Doron
Publisher: name: arXiv
Year: 2017
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We analyze the full statistics of a stochastic squeeze process. The model's two parameters are the bare stretching rate~$w$, and the angular diffusion coefficient~$D$. We carry out an exact analysis to determine the drift and the diffusion coefficient of $\log(r)$, where $r$ is the radial coordinate. The results go beyond the heuristic lognormal description that is implied by the central limit theorem. Contrary to the common "Quantum Zeno" approximation, the radial diffusion is not simply $D_r = (1/8)w^2/D$, but has a non-monotonic dependence on $w/D$. Furthermore, the calculation of the radial moments is dominated by the far non-Gaussian tails of the $\log(r)$ distribution.
description: 12 pages, 8 figures, final version
Evolution of protoplanetary disks from their taxonomy in scattered light: Group I vs. Group II
Creators: name: Garufi, Antonio
name: Meeus, Gwendolyn
name: Benisty, Myriam
name: Quanz, Sascha
name: Banzatti, Andrea
name: Kama, Mihkel
name: Canovas, Hector
name: Eiroa, Carlos
name: Schmid, Hans Martin
name: Stolker, Tomas
name: Pohl, Adriana
name: Rigliaco, Elisabetta
name: Menard, Francois
name: Meyer, Micheal
name: van Boekel, Roy
name: Dominik, Carsten
Publisher: name: arXiv
Year: 2017
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: High-resolution imaging reveals a large morphological variety of protoplanetary disks. To date, no constraints on their global evolution have been found from this census. An evolutionary classification of disks was proposed based on their IR spectral energy distribution, with the Group I sources showing a prominent cold component ascribed to an earlier stage of evolution than Group II. Disk evolution can be constrained from the comparison of disks with different properties. A first attempt of disk taxonomy is now possible thanks to the increasing number of high-resolution images of Herbig Ae/Be stars becoming available. Near-IR images of six Group II disks in scattered light were obtained with VLT/NACO in Polarimetric Differential Imaging, which is the most efficient technique to image the light scattered by the disk material close to the stars. We compare the stellar/disk properties of this sample with those of well-studied Group I sources available from the literature. Three Group II disks are detected. The brightness distribution in the disk of HD163296 indicates the presence of a persistent ring-like structure with a possible connection with the CO snowline. A rather compact (less than 100 AU) disk is detected around HD142666 and AK Sco. A taxonomic analysis of 17 Herbig Ae/Be sources reveals that the difference between Group I and Group II is due to the presence or absence of a large disk cavity (larger than 5 AU). There is no evidence supporting the evolution from Group I to Group II. Group II are not evolved version of the Group I. Within the Group II disks, very different geometries (both self-shadowed and compact) exist. HD163296 could be the primordial version of a typical Group I. Other Group II, like AK Sco and HD142666, could be smaller counterpart of Group I unable to open cavities as large as those of Group I.
description: 16 pages, 7 figures, published by A&A
Generic dynamical features of quenched interacting quantum systems: Survival probability, density imbalance and out-of-time-ordered correlator
Creators: name: Torres-Herrera, E. J.
name: García-García, Antonio M.
name: Santos, Lea F.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study numerically and analytically the quench dynamics of isolated many-body quantum systems. Using full random matrices from the Gaussian orthogonal ensemble, we obtain analytical expressions for the evolution of the survival probability, density imbalance, and out-of-time-ordered correlator. They are compared with numerical results for a one-dimensional disordered model with two-body interactions and shown to bound the decay rate of this realistic system. Power-law decays are seen at intermediate times and dips below the infinite time averages (correlation holes) occur at long times for all three quantities when the system exhibits level repulsion. The fact that these features are shared by both the random matrix and the realistic disordered model indicates that they are generic to nonintegrable interacting quantum systems out of equilibrium. Assisted by the random matrix analytical results, we propose expressions that describe extremely well the dynamics of the realistic chaotic system at different time scales.
description: 5 pages, 3 figures
Self-Correcting Models for Model-Based Reinforcement Learning
Creators: name: Talvitie, Erik
Publisher: name: arXiv
Year: 2016
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences
subject: I.2.6; I.2.8

description: When an agent cannot represent a perfectly accurate model of its environment's dynamics, model-based reinforcement learning (MBRL) can fail catastrophically. Planning involves composing the predictions of the model; when flawed predictions are composed, even minor errors can compound and render the model useless for planning. Hallucinated Replay (Talvitie 2014) trains the model to "correct" itself when it produces errors, substantially improving MBRL with flawed models. This paper theoretically analyzes this approach, illuminates settings in which it is likely to be effective or ineffective, and presents a novel error bound, showing that a model's ability to self-correct is more tightly related to MBRL performance than one-step prediction error. These results inspire an MBRL algorithm for deterministic MDPs with performance guarantees that are robust to model class limitations.
description: Original paper appeared in Proceedings of the 31st AAAI Conference on Artificial Intelligence, 2017. This version incorporates the appendix into document (rather than as supplementary material), corrects a minor error in Lemma 1, and fixes some type-os
Fate of in-medium heavy quarks via a Lindblad equation
Creators: name: De Boni, Davide
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: What is the dynamics of heavy quarks and antiquarks in a quark gluon plasma? Can heavy-quark bound states dissociate? Can they (re)combine? These questions are addressed by investigating a Lindblad equation that describes the quantum dynamics of the heavy quarks in a medium. The Lindblad equations for a heavy quark and a heavy quark-antiquark pair are derived from the gauge theory, following a chain of well-defined approximations. In this work the case of an abelian plasma has been considered, but the extension to the non-abelian case is feasible. A one-dimensional simulation of the Lindblad equation is performed to extract information about bound-state dissociation, recombination and quantum decoherence for a heavy quark-antiquark pair. All these phenomena are found to depend strongly on the imaginary part of the inter-quark potential.
description: 50 pages, 10 figures - added references - corrected typos and added a few comments - added appendix D
Numerical Simulations of a Jet-Cloud Collision and Starburst: Application to Minkowski's Object
Creators: name: Fragile, P. Chris
name: Anninos, Peter
name: Croft, Steve
name: Lacy, Mark
name: Witry, Jason W. L.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present results of three-dimensional, multi-physics simulations of an AGN jet colliding with an intergalactic cloud. The purpose of these simulations is to assess the degree of "positive feedback," i.e. jet-induced star formation, that results. We have specifically tailored our simulation parameters to facilitate comparison with recent observations of Minkowski's Object (M.O.), a stellar nursery located at the termination point of a radio jet coming from galaxy NGC 541. As shown in our simulations, such a collision triggers shocks which propagate around and through the cloud. These shocks condense the gas and under the right circumstances may trigger cooling instabilities, creating runaway increases in density, to the point that individual clumps can become Jeans unstable. Our simulations provide information about the expected star formation rate, total mass converted to \ion{H}{1}, H$_2$, and stars, and the relative velocity of the stars and gas. Our results confirm the possibility of jet-induced star formation, and agree well with the observations of M.O.
description: 11 pages, 6 figures, ApJ accepted version
Ionization potential depression and dynamical structure factor in dense plasmas
Creators: name: Lin, Chengliang
name: Röpke, Gerd
name: Kraeft, Wolf-Dietrich
name: Reinholz, Heidi
Publisher: name: arXiv
Year: 2017
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The properties of a bound electron system immersed in a plasma environment are strongly modified by the surrounding plasma. The modification of a basic quantity, the ionization energy, is described by the electronic self-energy and by dynamical screening within the framework of the quantum statistical theory. Introducing the ionic dynamical structure factor as the indicator for the ionic micro-field, we demonstrate that ionic correlations and fluctuations play a critical role in determining the ionization potential depression. This is in particular true for mixtures of different ions with large mass and charge asymmetry. The ionization potential depression is calculated for dense aluminum plasmas as well as for a CH plasma and compared to the experimental data and more phenomenological approaches used so far.
Impact of Rare Decays $t \to \ell' νb \ell\ell$ and $t \to q q' b \ell\ell$ on Searches for Top-Associated Physics
Creators: name: Onyisi, Peter
name: Webb, Aaron
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Searches for top quark-associated physics such as $t\bar t W$ or $t\bar t H$ in final states with multiple leptons require a careful accounting of expected backgrounds due to the lack of reconstructible resonances. We demonstrate that the rare top quark decays $t \to \ell' νb \ell\ell$ and $t \to q q' b \ell\ell$, when a soft lepton is not detected, can contribute a non-negligible background to such searches. Simulations in the LHC experiments typically do not account for such decays and as such backgrounds to such searches may be underestimated.
description: 13 pages, 6 figures
Difference between two species of emu hides a test for lepton flavour violation
Creators: name: Lester, Christopher Gorham
name: Brunt, Benjamin Hylton
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We argue that an LHC measurement of some simple quantities related to the ratio of rates of e+mu- to e-mu+ events is surprisingly sensitive to as-yet unexcluded R-parity violating supersymmetric models with non-zero lambda-prime 231 couplings. The search relies upon the approximate lepton universality in the Standard Model, the sign of the charge of the proton, and a collection of favourable detector biases. The proposed search is unusual because: it does not require any of the displaced vertices, hadronic neutralino decay products, or squark/gluino production relied upon by existing LHC RPV searches; it could work in cases in which the only light sparticles were smuons and neutralinos; and it could make a discovery (though not necessarily with optimal significance) without requiring the computation of a leading-order Monte Carlo estimate of any background rate. The LHC has shown no strong hints of post-Higgs physics and so precision Standard Model measurements are becoming ever more important. We argue that in this environment growing profits are to be made from searches that place detector biases and symmetries of the Standard Model at their core - searches based around `controls' rather than around signals.
description: 17 page, 7 figs; v2: reference added; v3: clarified statement about W+jet bias; v4: changes from referee comments, inc addition of quantitative bias estimate. Replaced ptmiss with mt(mu); v5: fixes error introduced in v4 (ptmiss should have been replaced by mT(e)+mT(mu) not by mT(mu)). An erratum is also submitted to JHEP. Error is not present in arXiv v1, v2, v3 or v5
Complex Quasi-Two-Dimensional Crystalline Order Embedded in VO$_2$ and Other Crystals
Creators: name: Lovorn, Timothy
name: Sarker, Sanjoy K.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Metal oxides such as VO$_2$ undergo structural transitions to low-symmetry phases characterized by intricate crystalline order, accompanied by rich electronic behavior. We derive a minimal ionic Hamiltonian based on symmetry and local energetics which describes structural transitions involving all four observed phases, in the correct order. An exact analysis shows that complexity results from the symmetry-induced constraints of the parent phase which forces ionic displacements to form multiple interpenetrating groups using low-dimensional pathways and distant neighbors. Displacements within each group exhibit independent, quasi two-dimensional order, which is frustrated and fragile. This selective ordering mechanism is not restricted to VO$_2$: it applies to other oxides which show similar complex order.
description: 5 pages, 3 figures
Enhancing quantum control by bootstrapping a quantum processor of 12 qubits
Creators: name: Lu, Dawei
name: Li, Keren
name: Li, Jun
name: Katiyar, Hemant
name: Park, Annie Jihyun
name: Feng, Guanru
name: Xin, Tao
name: Li, Hang
name: Long, GuiLu
name: Brodutch, Aharon
name: Baugh, Jonathan
name: Zeng, Bei
name: Laflamme, Raymond
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Accurate and efficient control of quantum systems is one of the central challenges for quantum information processing. Current state-of-the-art experiments rarely go beyond 10 qubits and in most cases demonstrate only limited control. Here we demonstrate control of a 12-qubit system, and show that the system can be employed as a quantum processor to optimize its own control sequence by using measurement-based feedback control (MQFC). The final product is a control sequence for a complex 12-qubit task: preparation of a 12-coherent state. The control sequence is about 10% more accurate than the one generated by the standard (classical) technique, showing that MQFC can correct for unknown imperfections. Apart from demonstrating a high level of control over a relatively large system, our results show that even at the 12-qubit level, a quantum processor can be a useful lab instrument. As an extension of our work, we propose a method for combining the MQFC technique with a twirling protocol, to optimize the control sequence that produces a desired Clifford gate.
description: The published version in npj Quantum Information
Universal scaling of strange particle $p_{\rm T}$ spectra in pp collisions
Creators: name: Yang, Liwen
name: Wang, Yanyun
name: Hao, Wenhui
name: Liu, Na
name: Du, Xiaoling
name: Zhang, Wenchao
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: As a complementary study to that performed on the transverse momentum ($p_{\rm T}$) spectra of charged pions, kaons and protons in proton-proton (pp) collisions at LHC energies 0.9, 2.76 and 7 TeV, we present a scaling behaviour in the $p_{\rm T}$ spectra of strange particles ($K_{S}^{0}$, $\rm Λ$, $\rm Ξ$ and $ϕ$) at these three energies. This scaling behaviour is exhibited when the spectra are expressed in a suitable scaling variable $z=p_{\rm T}/K$, where the scaling parameter $K$ is determined by the quality factor method and increases with the center of mass energy ($\sqrt{s}$). The rates at which $K$ increases with $\mathrm{ln}\sqrt{s}$ for these strange particles are found to be identical within errors. In the framework of the colour string percolation model, we argue that these strange particles are produced through the decay of clusters that are formed by the colour strings overlapping. We observe that the strange mesons and baryons are produced from clusters with different size distributions, while the strange mesons (baryons) $K_{S}^{0}$ and $ϕ$ ($\rm Λ$ and $\rm Ξ$) originate from clusters with the same size distributions. The cluster's size distributions for strange mesons are more dispersed than those for strange baryons. The scaling behaviour of the $p_{\rm T}$ spectra for these strange particles can be explained by the colour string percolation model in a quantitative way.
description: 8 pages, 10 figures, accepted by EPJA
Charge and energy fractionalization mechanism in one-dimensional channels
Creators: name: Acciai, Matteo
name: Calzona, Alessio
name: Dolcetto, Giacomo
name: Schmidt, Thomas L.
name: Sassetti, Maura
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the problem of injecting single electrons into interacting one-dimensional quantum systems, a fundamental building block for electron quantum optics. It is well known that such injection leads to charge and energy fractionalization. We elucidate this concept by calculating the nonequilibrium electron distribution function in the momentum and energy domains after the injection of an energy-resolved electron. Our results shed light on how fractionalization occurs via the creation of particle-hole pairs by the injected electron. In particular, we focus on systems with a pair of counterpropagating channels, and we fully analyze the properties of each chiral fractional excitation which is created by the injection. We suggest possible routes to access their energy and momentum distribution functions in topological quantum Hall or quantum spin-Hall edge states.
description: 13 pages, 6 figures
The role of correlations in the collective behaviour of microswimmer suspensions
Creators: name: Stenhammar, Joakim
name: Nardini, Cesare
name: Nash, Rupert W.
name: Marenduzzo, Davide
name: Morozov, Alexander
Publisher: name: arXiv
Year: 2017
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Biological Physics (physics.bio-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: In this Letter, we study the collective behaviour of a large number of self-propelled microswimmers immersed in a fluid. Using unprecedently large-scale lattice Boltzmann simulations, we reproduce the transition to bacterial turbulence. We show that, even well below the transition, swimmers move in a correlated fashion that cannot be described by a mean-field approach. We develop a novel kinetic theory that captures these correlations and is non-perturbative in the swimmer density. To provide an experimentally accessible measure of correlations, we calculate the diffusivity of passive tracers and reveal its non-trivial density dependence. The theory is in quantitative agreement with the lattice Boltzmann simulations and captures the asymmetry between pusher and puller swimmers below the transition to turbulence.
description: Accepted for publication in Phys. Rev. Lett
Sub-picosecond acoustic pulses at buried GaP/Si interfaces
Creators: name: Ishioka, Kunie
name: Rustagi, Avinash
name: Beyer, Andreas
name: Stolz, Wolfgang
name: Volz, Kerstin
name: Hoefer, Ulrich
name: Petek, Hrvoje
name: Stanton, Christopher J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report on the optical generation and detection of ultrashort acoustic pulses that propagate in three-dimensional semiconductor crystals. Photoexcitaiton of lattice-matched GaP layers grown on Si(001) gives rise to a sharp spike in transient reflectivity due to the acoustic pulse generated at the GaP/Si interface and detected at the GaP surface and vice versa. The extremely short width of the reflectivity spike, 0.5 ps, would translate to a spatial extent of 3 nm or 10 atomic bilayers, which is comparable with the width of the intermixing layer at the GaP/Si interface. The reflectivity signals are also modified by quasi-periodic Brillouin oscillations of GaP and Si arising from the acoustic pulses during the propagation in the crystals. The present results demonstrate the potential application of the simple optical pump-probe scheme in the nondestructive evaluation of the buried semiconductor interface quality.
description: 5 pages, 4 figures
Phonon-assisted oscillatory exciton dynamics in monolayer MoSe2
Creators: name: Chow, Colin M.
name: Yu, Hongyi
name: Jones, Aaron M.
name: Schaibley, John R.
name: Koehler, Michael
name: Mandrus, David G.
name: Merlin, R.
name: Yao, Wang
name: Xu, Xiaodong
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In monolayer semiconductor transition metal dichalcogenides, the exciton-phonon interaction is expected to strongly affect the photocarrier dynamics. Here, we report on an unusual oscillatory enhancement of the neutral exciton photoluminescence with the excitation laser frequency in monolayer MoSe2. The frequency of oscillation matches that of the M-point longitudinal acoustic phonon, LA(M). Oscillatory behavior is also observed in the steady-state emission linewidth and in timeresolved photoluminescence excitation data, which reveals variation with excitation energy in the exciton lifetime. These results clearly expose the key role played by phonons in the exciton formation and relaxation dynamics of two-dimensional van der Waals semiconductors.
description: Published in npj 2D Materials and Applications. https://www.nature.com/articles/s41699-017-0035-1
What are indirect treatment comparisons and why do we need them?
Creators: name: Harvey, Elizabeth
Publisher: name: figshare
Year: 2022
Subjects: subject: 111504 Pharmaceutical Sciences
subject: FOS: Clinical medicine

description: There is a need for consistent use of plain language communications to support patient involvement in health economics and outcomes research (HEOR). This summary provides a plain language explanation of the methods and purpose of indirect treatment comparisons to assess new medical products, and what this means for healthcare funding
“Steeped in Oil”: The Socio-Psychological Factors and Processes That Influence Community Members’ Attitudes toward Economic Diversification in an Oil and Gas-Producing Community
Creators: name: Murphy, Kathleen
name: Stone, Kathryn
name: Cameron, Emma Stirling
name: Strand, Lola
name: Combs, Chaise
name: Khan, Anam
name: Ungar, Michael
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Ecology
subject: FOS: Biological sciences
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: Science Policy

description: Oil and gas-producing communities are threatened by a precarious oil market and global commitments to transition to a greener economy. Economic diversification has been proposed as a potential strategy for supporting the resilience of these communities amidst such challenges. We sought to explore community members’ attitudes toward the future of their small oil and gas-producing Canadian community to understand the socio-psychological factors and processes that influence their support for economic diversification and those which reinforce path dependency. This qualitative study involved interviews with 37 adults in the community, and a subset of 16 of those participants engaged in transect walks to further explore emerging themes. While the recent prolonged economic downturn prompted some participants’ willingness to diversify, the deeply ingrained culture and identity as an oil and gas town, the ‘golden handcuffs’ of the industry, and optimism for another boom, acted to reinforce path dependency.
Magnetic hexadecapole order and magnetopiezoelectric metal in Ba$_{1-x}$K$_x$Mn$_2$As$_2$
Creators: name: Watanabe, Hikaru
name: Yanase, Youichi
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We study an odd-parity magnetic multipole order in Ba$_{1-x}$K$_x$Mn$_2$As$_2$ and related materials. Although BaMn$_2$As$_2$ is a seemingly conventional Mott insulator with G-type antiferromagnetic order, we identify the ground state as a magnetic hexadecapole ordered state accompanied by simultaneous time-reversal and space-inversion symmetry breaking. A symmetry argument and microscopic calculations reveal the ferroic ordering of leading magnetic hexadecapole moment and admixed magnetic quadrupole moment. Furthermore, we clarify electromagnetic responses characterizing the magnetic hexadecapole state of semiconducting BaMn$_2$As$_2$ and doped metallic systems. A magnetoelectric effect and antiferromagnetic Edelstein effect are shown. Interestingly, a counter-intuitive currentinduced nematic order occurs in the metallic state. The electric current along the \textit{z}-axis induces the \textit{xy}-plane nematicity in sharp contrast to the spontaneous nematic order in superconducting Febased 122-compounds. Thus, the magnetic hexadecapole state of doped BaMn$_2$As$_2$ is regarded as a magnetopiezoelectric metal. The anomalous responses stem from the peculiar symmetry of the parity-violating magnetic order. Other candidate materials for magnetic hexadecapole order are proposed.
description: 19 pages, 13 figures, 4 tables
Non-Fermi-liquid at (2+1)d ferromagnetic quantum critical point
Creators: name: Xu, Xiao Yan
name: Sun, Kai
name: Schattner, Yoni
name: Berg, Erez
name: Meng, Zi Yang
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We construct a two-dimensional lattice model of fermions coupled to Ising ferromagnetic critical fluctuations. Using extensive sign-problem-free quantum Monte Carlo simulations, we show that the model realizes a continuous itinerant quantum phase transition. In comparison with other similar itinerant quantum critical points (QCPs), our QCP shows much weaker superconductivity tendency with no superconducting state down to the lowest temperature investigated, hence making the system a good platform for the exploration of quantum critical fluctuations. Remarkably, clear signatures of non-Fermi-liquid behavior in the fermion propagators are observed at the QCP. The critical fluctuations at the QCP partially resemble Hertz-Millis-Moriya behavior. However, careful scaling analysis reveals that the QCP belongs to a different universality class, deviating from both (2+1)d Ising and Hertz-Millis-Moriya predictions.
description: 12 pages, 14 figures
Supplementary Data Figure Legend
Creators: name: Ma, Ying
name: Han, Chuting
name: Xie, Cheng
name: Dang, Qingya
name: Yang, LiJu
name: Li, Yuan
name: Zhang, Min
name: Cheng, Jun
name: Yang, Yan
name: Xu, Qingbo
name: Li, Pengyun
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 310105
subject: Cellular interactions (incl. adhesion, matrix, cell wall)
classificationCode: 310110
subject: Receptors and membrane biology
classificationCode: 310111
subject: Signal transduction

description: Supplementday data Figure Legend： Supplementary Figure S1. ATP, UTP and UDP enhanced CD34+VW-SCs migration. Supplementary Figure S2. Effect of P2Y2 and P2Y6 inhibitor on CD34+VW-SCs viability examined by CCK-8 assay. Supplementary Figure S3. ATP induced STIM1 translocation into plasma membrane in STIM1-EYFP overexpressed T-REx HEK293 cells. Supplementary Figure S4. ATP induced STIM1 Phosphorylation determined by COIP in STIM1-EYFP overexpressed T-REx HEK293 cells.
Performance of Dynamic and Static TDD in Self-backhauled mmWave Cellular Networks
Creators: name: Kulkarni, Mandar N.
name: Andrews, Jeffrey G.
name: Ghosh, Amitava
Publisher: name: arXiv
Year: 2017
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Initial deployments of millimeter wave (mmWave) cellular networks are likely to be enabled with self-backhauling. In this work, we propose a random spatial model to analyze uplink (UL) and downlink (DL) SINR distribution and mean rates corresponding to different access-backhaul and UL-DL resource allocation schemes in a self-backhauled mmWave cellular network with Poisson point process (PPP) deployment of users and base stations. In particular, we focus on heuristic implementations of static and dynamic time division duplexing (TDD) for access links with synchronized or unsynchronized access-backhaul (SAB or UAB) time splits. We propose PPP approximations to characterize the distribution of the new types of interference encountered with dynamic TDD and UAB. These schemes offer better resource utilization than static TDD and SAB, however potentially higher interference makes their choice non-trivial and the offered gains sensitive to different network parameters, including UL/DL traffic asymmetry, user load per BS or number of slave BSs per master BS. One can harness notable gains from UAB and/or dynamic TDD only if backhaul links are designed to have much larger throughput than the access links.
description: appeared in IEEE Transactions on Wireless Communications. Corrected some typos compared to previous ArXiv version
Projective measurement onto arbitrary superposition of coherent state bases
Creators: name: Izumi, Shuro
name: Takeoka, Masahiro
name: Wakui, Kentaro
name: Fujiwara, Mikio
name: Ema, Kazuhiro
name: Sasaki, Masahide
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: One of the peculiar features in quantum mechanics is that a superposition of macroscopically distinct states can exits. In optical system, this is highlighted by a superposition of coherent states (SCS), i.e. a superposition of classical states. Recently this highly nontrivial quantum state and its variant have been demonstrated experimentally. Here we demonstrate the superposition of coherent states in quantum measurement which is also a key concept in quantum mechanics. More precisely, we propose and implement a projection measurement onto the arbitrary superposition of the SCS bases in optical system. The measurement operators are reconstructed experimentally by a novel quantum detector tomography protocol. Our device is realized by combining the displacement operation and photon counting, well established technologies, and thus has implications in various optical quantum information processing applications.
Supplementary Data_Chronic mitochondria antioxidant treatment in older adults alters the circulating milieu to improve endothelial cell function and mitochondrial oxidative stress_AJPHeart_2023_Murray
Creators: name: Murray, Kevin
name: Murray, Kevin
Publisher: name: figshare
Year: 2023
Subjects: Biochemistry and cell biology not elsewhere classified
Other biomedical and clinical sciences not elsewhere classified

description: Supplemental figures and detailed methods for American Journal of Physiology - Heart and Circulatory Physiology (May 2023). This data supports our findings that changes with the circulating milieu (lower oxLDL) with chronic MitoQ supplementation in older adults (older men and postmenopausal women) contributes to improvements in endothelial function in vivo in the same subjects providing novel insight to the mechanisms by which mitochondrial targeted antioxidant treatment improves endothelial function in older adults. Briefly, plasma collected from older adult subjects after chronic supplementation with a mitochondrial targeted antioxidant (MitoQ) improves endothelial cell function and reduces mitochondrial reactive oxygen species compared to plasma collected from the same older adult subjects after placebo supplementation.