cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Invariant Eigen-Structure in Complex-Valued Quantum Mechanics
Creators: name: Yang, C. D.
name: Han, S. Y.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The complex-valued quantum mechanics considers quantum motion on the complex plane instead of on the real axis, and studies the variations of a particle complex position, momentum and energy along a complex trajectory. On the basis of quantum Hamilton-Jacobi formalism in the complex space, we point out that having complex-valued motion is a universal property of quantum systems, because every quantum system is actually accompanied with an intrinsic complex Hamiltonian originating from the equation. It is revealed that the conventional real-valued quantum mechanics is a special case of the complex-valued quantum mechanics in that the eigen-structures of real and complex quantum systems, such as their eigenvalues, eigenfunctions and eigen-trajectories, are invariant under linear complex mapping. In other words, there is indeed no distinction between Hermitian systems, PT-symmetric systems, and non PT-symmetric systems when viewed from a complex domain. Their eigen-structures can be made coincident through linear transformation of complex coordinates.
Can We Trust the Dust? Evidence of Dust Segregation in Molecular Clouds
Creators: name: Padoan, Paolo
name: Cambresy, Laurent
name: Juvela, Mika
name: Kritsuk, Alexei
name: Langer, William D.
name: Norman, Michael L.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Maps of estimated dust column density in molecular clouds are usually assumed to reliably trace the total gas column density structure. In this work we present results showing a clear discrepancy between the dust and the gas distribution in the Taurus molecular cloud complex. We compute the power spectrum of a 2MASS extinction map of the Taurus region and find it is much shallower than the power spectrum of a 13CO map of the same region previously analyzed. This discrepancy may be explained as the effect of grain growth on the grain extinction efficiency. However, this would require a wide range of maximum grain sizes, which is ruled out based on constraints from the extinction curve and the available grain models. We show that major effects due to CO formation and depletion are also ruled out. Our result may therefore suggest the existence of intrinsic spatial fluctuations of the dust to gas ratio, with amplitude increasing toward smaller scales. Preliminary results of numerical simulations of trajectories of inertial particles in turbulent flows illustrate how the process of clustering of dust grains by the cloud turbulence may lead to observable effects. However, these results cannot be directly applied to large scale supersonic and magnetized turbulence at present.
description: 10 pages, 8 figures included, ApJ, in press
Natascha Sojc – Aloys Winterling – Ulrike Wulf-Rheidt (Hgg.), Palast und Stadt im severischen Rom
Creators: name: Lorenz, Jürgen
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Rezension zu: Natascha Sojc – Aloys Winterling – Ulrike Wulf-Rheidt (Hgg.), Palast und Stadt im severischen Rom. Stuttgart: Franz Steiner Verlag 2013, 306 S., 98 s/w-Abb., 16 Farbtaf.
description: Göttinger Forum für Altertumswissenschaft, Bd. 17 (2014): Göttinger Forum für Altertumswissenschaft
HOW ARE HOSTILE IDENTITIES FORMED: A CASE STUDY OF KENYA & CAMEROON
Creators: name: Tebid, Norah-Frida
Publisher: name: American University
Year: 2023
Subjects: classificationCode: 4408
subject: Political science
subject: FOS: Political science

description: This paper sets out to examine exclusion and state predation, mistrust in state institutions, and negative attitudes about democracy as potential drivers of negative/hostile attitudes by members of particular ethnic groups towards the state. It addresses three questions. First, can the exclusion and predation by a state on a particular ethnic group cause members of that ethnic group to form negative attitudes towards said state? Second, can mistrust in state institutions and negative attitudes about democracy also move members of a particular ethnic group to form negative attitudes towards the state? And, finally, can those negative attitudes be mobilized in such a way that it leads to the formation of a hostile identity group? I will be using Afrobarometer data on Kenya and Cameroon to argue that marginalized ethnic groups, which refers to ethnic groups that have been shut out of the neo patrimonial systems that exist in Kenya and Cameroon will be more likely compared to ethnic groups that have historically been included in the patronage system in their respective states to form negative attitudes towards those states.
Exact electromagnetic duality with nonminimal couplings
Creators: name: Cano, Pablo A.
name: Murcia, Ángel
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study nonminimal extensions of Einstein-Maxwell theory with exact electromagnetic duality invariance. Any such theory involves an infinite tower of higher-derivative terms whose computation and summation usually represents a challenging problem. Despite that, we manage to obtain a closed form of the action for all the theories with a quadratic dependence on the vector field strength. In these theories we find that the Maxwell field couples to gravity through a curvature-dependent susceptibility tensor that takes a peculiar form, reminiscent of that of Born-Infeld Lagrangians. We study the static and spherically symmetric black hole solutions of the simplest of these models, showing that the corresponding equations of motion are invariant under rotations of the electric and magnetic charges. We compute the perturbative corrections to the Reissner-Nordström solution in this theory, and in the case of extremal black holes we determine exactly the near-horizon geometry as well as the entropy. Remarkably, the entropy only possesses a constant correction despite the action containing an infinite number of terms. In addition, we find there is a lower bound for the charge and the mass of extremal black holes. When the sign of the coupling is such that the weak gravity conjecture is satisfied, the area and the entropy of extremal black holes vanish at the minimal charge.
description: 7 pages, no figures. It matches version accepted for publication as a Letter in PRD. In this new version, we have included the explicit form of the action of all theories quadratic in the Maxwell field strength, as well as its derivation. Further adjustments associated to this inclusion and other minor fixes have also been performed
Anna Anguissola (Hg.), Privata Luxuria. Towards an Archaeology of Intimacy: Pompeii and Beyond
Creators: name: Trümper, Monika
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Rezension zu: Anna Anguissola (Hg.), Privata Luxuria. Towards an Archaeology of Intimacy: Pompeii and Beyond. International Workshop Center for Advanced Studies, Ludwig-Maximilians-Universität München (24-25 March 2011). Münchener Studien zur Alten Welt 8. München: Herbert Utz Verlag 2013, 244 S.
description: Göttinger Forum für Altertumswissenschaft, Bd. 17 (2014): Göttinger Forum für Altertumswissenschaft
Manipulating atom-number distributions and detecting spatial distributions in lattice-confined spinor gases
Creators: name: Austin, J. O.
name: Shaw, Z. N.
name: Chen, Z.
name: Mahmud, K. W.
name: Liu, Y.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We present an experimental study demonstrating the manipulation of atom-number distributions of spinor gases after nonequilibrium quantum quenches across superfluid to Mott-insulator phase transitions in cubic optical lattices. Our data indicate that atom distributions in individual Mott lobes can be tuned by properly designing quantum quench sequences, which suggests methods of maximizing the fraction of atoms in Mott lobes of even occupation numbers and has applications in attaining different quantum magnetic phases including massively entangled states. Spatial distributions of gases in three-dimensional lattices are derived from the observed number distributions, which reveal complex spatial dynamics during the quantum quenches. Qualitative agreements are also found between our experimental data and numerical simulations based on time-dependent Gutzwiller approximations in two-dimensional systems.
Wolfgang Ehrhardt, Dekorations- und Wohnkontext. Beseitigung, Restaurierung, Verschmelzung und Konservierung von Wandbemalungen in den kampanischen Antikenstätten
Creators: name: Matthaei, Albrecht
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Rezension zu: Wolfgang Ehrhardt, Dekorations- und Wohnkontext. Beseitigung, Restaurierung, Verschmelzung und Konservierung von Wandbemalungen in den kampanischen Antikenstätten. Palilia 26. Wiesbaden: Reichert Verlag 2012, 336 S., 355 Farbabb.
description: Göttinger Forum für Altertumswissenschaft, Bd. 17 (2014): Göttinger Forum für Altertumswissenschaft
The water ice rich surface of (145453) 2005 RR43: a case for a carbon-depleted population of TNOs?
Creators: name: Pinilla-Alonso, N.
name: Licandro, J.
name: Gil-Hutton, R.
name: Brunetto, R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Recent results suggest that there is a group of TNOs (2003 EL61 being the biggest member), with surfaces composed of almost pure water ice and with very similar orbital elements. We study the surface composition of another TNO that moves in a similar orbit, 2005 RR43, and compare it with the surface composition of the other members of this group. We report visible and near-infrared spectra, obtained with the 4.2m William Herschel Telescope and the 3.58m Telescopio Nazionale Galileo at the "Roque de los Muchachos" Observatory (La Palma, Spain). The spectrum of 2005 RR43 is neutral in color in the visible and dominated by very deep water ice absorption bands in the near infrared (D= 70.3 +/- 2.1 % and 82.8 +/- 4.9 % at 1.5 μand 2.0 μrespectively). It is very similar to the spectrum of the group of TNOs already mentioned. All of them present much deeper water ice absorption bands (D>40 %) than any other TNO except Charon. Scattering models show that its surface is covered by water ice, a significant fraction in crytalline state with no trace (5 % upper limit) of complex organics. Possible scenarios to explain the existence of this population of TNOs are discussed: a giant collision, an originally carbon depleted composition, or a common process of continuous resurfacing. We conclude that TNO 2005 RR43 is member of a group, may be a population, of TNOs clustered in the space of orbital parameters that show abundant water ice and no signs of complex organics. The lack of complex organics in their surfaces suggests a significant smaller fraction of carbonaceous volatiles like CH4 in this population than in "normal" TNOs. A carbon depleted population of TNOs could be the origin of the population of carbon depleted Jupiter family comets already noticed by A'Hearn et al. (1995).
description: Final Version (Paper Accepted) 4 pages, 2 figures. Changed title, abstract, discussion
Geometric quantization of Hamiltonian actions of Lie algebroids and Lie groupoids
Creators: name: Bos, Rogier
Publisher: name: arXiv
Year: 2006
Subjects: subject: Symplectic Geometry (math.SG)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 22A22; 58H05; 53D50

description: We construct Hermitian representations of Lie algebroids and associated unitary representations of Lie groupoids by a geometric quantization procedure. For this purpose we introduce a new notion of Hamiltonian Lie algebroid actions. The first step of our procedure consists of the construction of a prequantization line bundle. Next, we discuss a version of Kähler quantization suitable for this setting. We proceed by defining a Marsden-Weinstein quotient for our setting and prove a ``quantization commutes with reduction'' theorem. We explain how our geometric quantization procedure relates to a possible orbit method for Lie groupoids. Our theory encompasses the geometric quantization of symplectic manifolds, Hamiltonian Lie algebra actions, actions of families of Lie groups, foliations, as well as some general constructions from differential geometry.
description: 40 pages, corrected version 11-01-2006
A Graphical Interpretation of Circumgalactic Precipitation
Creators: name: Voit, G. M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Both observations and recent numerical simulations of the circumgalactic medium (CGM) support the hypothesis that a self-regulating feedback loop suspends the gas density of the ambient CGM close to the galaxy in a state with a ratio of cooling time to freefall time >10. This limiting ratio is thought to arise because circumgalactic gas becomes increasingly susceptible to multiphase condensation as the ratio declines. If the timescale ratio gets too small, then cold clouds precipitate out of the CGM, rain into the galaxy, and fuel energetic feedback that raises the ambient cooling time. The astrophysical origin of this so-called precipitation limit is not simple but is critical to understanding the CGM and its role in galaxy evolution. This paper therefore attempts to interpret its origin as simply as possible, relying mainly on conceptual reasoning and schematic diagrams. It illustrates how the precipitation limit can depend on both the global configuration of a galactic atmosphere and the degree to which dynamical disturbances drive CGM perturbations. It also frames some tests of the precipitation hypothesis that can be applied to both CGM observations and numerical simulations of galaxy evolution.
description: 10 pages, 3 figures, accepted to ApJ Letters
Generators and relations for the etale fundamental group
Creators: name: Lieblich, Max
name: Olsson, Martin
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Geometry (math.AG)
subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 14H30

description: If $C$ is a smooth curve over an algebraically closed field $k$ of characteristic $p$, then the structure of the maximal prime to $p$ quotient of the étale fundamental group is known by analytic methods. In this paper, we discuss the properties of the fundamental group that can be deduced by purely algebraic techniques. We describe a general reduction from an arbitrary curve to the projective line minus three points, and show what can be proven unconditionally about the maximal pro-nilpotent and pro-solvable quotients of the prime-to-$p$ fundamental group. Included is an appendix which treats the tame fundamental group from a stack-theoretic perspective.
description: 26 pages. Significant revision; errors corrected, various points clarified
A continuous-time Ehrenfest model with catastrophes and its jump-diffusion approximation
Creators: name: Dharmaraja, Selvamuthu
name: Di Crescenzo, Antonio
name: Giorno, Virginia
name: Nobile, Amelia G.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60J80, 60J27, 60J60

description: We consider a continuous-time Ehrenfest model defined over the integers from -N to N, and subject to catastrophes occurring at constant rate. The effect of each catastrophe instantaneously resets the process to state 0. We investigate both the transient and steady-state probabilities of the above model. Further, the first passage time through state 0 is discussed. We perform a jump-diffusion approximation of the above model, which leads to the Ornstein-Uhlenbeck process with catastrophes. The underlying jump-diffusion process is finally studied, with special attention to the symmetric case arising when the Ehrenfest model has equal upward and downward transition rates.
description: 21 pages, 10 figures
A more direct representation for complex relativity
Creators: name: Delphenich, David
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: An alternative to the representation of complex relativity by self-dual complex 2-forms on the spacetime manifold is presented by assuming that that the bundle of real 2-forms is given an almost-complex structure. From this, one can define a complex orthogonal structure on the bundle of 2-forms, which results in a more direct representation of the complex orthogonal group in three complex dimensions. The geometrical foundations of general relativity are then presented in terms of the bundle of oriented complex orthogonal 3-frames on the bundle of 2-forms in a manner that essentially parallels their construction in terms of self-dual complex 2-forms. It is shown that one can still discuss the Debever-Penrose classification of the Riemannian curvature tensor in terms of the representation presented here.
description: 33 pages
High-Fidelity Bell-State Preparation with $^{40}$Ca$^+$ Optical Qubits
Creators: name: Clark, Craig R.
name: Tinkey, Holly N.
name: Sawyer, Brian C.
name: Meier, Adam M.
name: Burkhardt, Karl A.
name: Seck, Christopher M.
name: Shappert, Christopher M.
name: Guise, Nicholas D.
name: Volin, Curtis E.
name: Fallek, Spencer D.
name: Hayden, Harley T.
name: Rellergert, Wade G.
name: Brown, Kenton R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Entanglement generation in trapped-ion systems has relied thus far on two distinct but related geometric phase gate techniques: Molmer-Sorensen and light-shift gates. We recently proposed a variant of the light-shift scheme where the qubit levels are separated by an optical frequency [B. C. Sawyer and K. R. Brown, Phys. Rev. A 103, 022427 (2021)]. Here we report an experimental demonstration of this entangling gate using a pair of $^{40}$Ca$^+$ ions in a cryogenic surface-electrode ion trap and a commercial, high-power, 532 nm Nd:YAG laser. Generating a Bell state in 35 $μ$s, we directly measure an infidelity of $6(3) \times 10^{-4}$ without subtraction of experimental errors. The 532 nm gate laser wavelength suppresses intrinsic photon scattering error to $\sim 1 \times 10^{-5}$.
description: 7 pages, 6 figures, should match published version
Strong spin-orbit coupling effects on the Fermi surface of Sr2RuO4 and Sr2RhO4
Creators: name: Haverkort, M. W.
name: Elfimov, I. S.
name: Tjeng, L. H.
name: Sawatzky, G. A.
name: Damascelli, A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We present a first-principle study of spin-orbit coupling effects on the Fermi surface of Sr2RuO4 and Sr2RhO4. For nearly degenerate bands, spin-orbit coupling leads to a dramatic change of the Fermi surface with respect to non-relativistic calculations; as evidenced by the comparison with experiments on Sr2RhO4, it cannot be disregarded. For Sr2RuO4, the Fermi surface modifications are more subtle but equally dramatic in the detail: spin-orbit coupling induces a strong momentum dependence, normal to the RuO2 planes, for both orbital and spin character of the low-energy electronic states. These findings have profound implications for the understanding of unconventional superconductivity in Sr2RuO4.
description: A high-resolution version can be found at http://www.physics.ubc.ca/~quantmat/ARPES/PUBLICATIONS/Articles/SO_Sr2RuO4.pdf
Holger Sonnabend, Katastrophen in der Antike
Creators: name: Ehmig, Ulrike
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Rezension zu: Holger Sonnabend, Katastrophen in der Antike. Darmstadt/Mainz: Verlag Philipp von Zabern 2013, 160 S., 19 s/w- und Farb-Abb.
description: Göttinger Forum für Altertumswissenschaft, Bd. 17 (2014): Göttinger Forum für Altertumswissenschaft
A qualitative investigation of factors influencing successful reward-based crowdfunding campaigns in the UK and China
Creators: name: Phillips, Robert
Publisher: name: figshare
Year: 2021
Subjects: subject: 150304 Entrepreneurship
subject: FOS: Economics and business

description: Crowdfunding is a means of accessing funding for a new project in exchange for equity, interest payments, or nonmonetary rewards that can be physical or digital. It is different from traditional funding in the sense that it relies on large numbers of people investing small sums of money, making it less risky for individual investors, rather than a large sum from a venture capitalist. We interviewed project founders in the United Kingdom and China and the similarities and differences between successful reward-model campaigns were analyzed. It was found that, while there are several similarities, there were some interesting differences. For example, Chinese founders hired click farmers to push their project up the rankings on the crowdfunding site, used certain colors that had cultural significance in their pitch, and a heavily discounted preorder was suggested as the best way of enticing a relatively risk-averse crowd. This article should help those project founders who are considering a crowdfunding campaign in either country to maximize their chances of success.
Peter I. Schneider – Ulrike Wulf-Rheidt (Hgg.), Licht – Konzepte in der vormodernen Architektur
Creators: name: Schulz-Brize, Thekla
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Rezension zu: Peter I. Schneider – Ulrike Wulf-Rheidt (Hgg.), Licht – Konzepte in der vormodernen Architektur. Diskussionen zur Archäologischen Bauforschung 10, Internationales Kolloquium in Berlin vom 26.02.-01.03.2009 veranstaltet vom Architekturreferat des DAI. Regensburg: Verlag Schnell und Steiner 2011, 394 S., 397 Abb., 1 Übersichtskarte
description: Göttinger Forum für Altertumswissenschaft, Bd. 17 (2014): Göttinger Forum für Altertumswissenschaft
Reconstructing 1/2 BPS Space-Time Metrics from Matrix Models and Spin Chains
Creators: name: Vazquez, Samuel E.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Using the AdS/CFT correspondence, we address the question of how to measure complicated space-time metrics using gauge theory probes. In particular, we consider the case of the 1/2 BPS geometries of type IIB supergravity. These geometries are classified by certain "droplets" in a two dimensional space-like hypersurface. We show how to reconstruct the full metric inside these droplets using the one-loop ${\cal N} = 4$ SYM theory dilatation operator. This is done by considering long operators in the SU(2) sector, which are dual to fast rotating strings on the droplets. We develop new powerful techniques for large $N$ complex matrix models that allow us to construct the Hamiltonian for these strings. We find that the Hamiltonian can be mapped to a "dynamical" spin chain. That is, the length of the chain is not fixed. Moreover, all of these spin chains can be explicitly constructed using an interesting algebra which is derived from the matrix model. Our techniques work for general droplet configurations. As an example, we study a single elliptical droplet and the "Hypotrochoid".
description: 14 pages, 3 figures, revtex4 format
Christian Ellinghaus, Die Parthenonskulpturen. Der Bauschmuck eines öffentlichen Monumentes der demokratischen Gesellschaft Athens zur Zeit des Perikles – Techniken in der bildenden Kunst zur Tradierung von Aussagen
Creators: name: Queyrel, François
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Rezension zu: Christian Ellinghaus, Die Parthenonskulpturen. Der Bauschmuck eines öffentlichen Monumentes der demokratischen Gesellschaft Athens zur Zeit des Perikles – Techniken in der bildenden Kunst zur Tradierung von Aussagen. Antiquitates, Archäologogische Forschungsergebnisse 52. Hamburg: Verlag Dr. Kovač 2011, 504 S.
description: Göttinger Forum für Altertumswissenschaft, Bd. 17 (2014): Göttinger Forum für Altertumswissenschaft
Dieter Hertel, Die Bildnisse des Tiberius
Creators: name: Hildebrandt, Frank
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Rezension zu: Dieter Hertel, Die Bildnisse des Tiberius. Das Römische Herrscherbild Abt. I Bd. 3, herausgegeben von Klaus Fittschen, Tonio Hölscher, Paul Zanker. Wiesbaden: Reichert Verlag 2013, XXII + 249 S., 11 Beil. mit 98 Strich-Abb., 142 Taf. mit 544 s/w-Abb.
description: Göttinger Forum für Altertumswissenschaft, Bd. 17 (2014): Göttinger Forum für Altertumswissenschaft
Nonlinear response theories and effective pair potentials
Creators: name: Gravel, Simon
name: Ashcroft, N. W.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a general method based on nonlinear response theory to obtain effective interactions between ions in an electron gas which can also be applied to other systems where an adiabatic separation of time-scales is possible. Nonlinear contributions to the interatomic potential are expressed in terms of physically meaningful quantities, giving insight in the physical properties of the system. The method is applied to various test cases and is found to improve the standard linear and quadratic response approaches. It also reduces the discrepancies previously observed between perturbation theory and density-functional theory results for the proton-proton pair potentials in metallic environments.
description: 16 pages, 8 figures. v2: some added references, and a few minor modifications. To appear in Phys. Rev. B
Forschungen über die rechtlichen Grundlagen der römischen Außenbeziehungen während der Republik bis zum Beginn des Prinzipats
Creators: name: Zack, Andreas
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Göttinger Forum für Altertumswissenschaft, Bd. 17 (2014): Göttinger Forum für Altertumswissenschaft
Neues im ‚Alexanderland‘: Ein frühhellenistisches Bildnis Alexanders des Großen
Creators: name: Hoff, Ralf Von Den
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Göttinger Forum für Altertumswissenschaft, Bd. 17 (2014): Göttinger Forum für Altertumswissenschaft
Die Allegorie vom 'funus Romae' in Lucans 'Bellum Civile'
Creators: name: Blaschka, Karen
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Göttinger Forum für Altertumswissenschaft, Bd. 17 (2014): Göttinger Forum für Altertumswissenschaft
'notiora, clariora, maiora tu facies' – Plinius und seine denkwürdige Heldentat (epist. 7,33)
Creators: name: Beck, Jan-Wilhelm
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Göttinger Forum für Altertumswissenschaft, Bd. 17 (2014): Göttinger Forum für Altertumswissenschaft
Localization of Dirac modes in finite-temperature $\mathbb{Z}_2$ gauge theory on the lattice
Creators: name: Baranka, György
name: Giordano, Matteo
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We study the localization properties of the eigenmodes of the staggered Dirac operator in finite-temperature $\mathbb{Z}_2$ pure gauge theory on the lattice in 2+1 dimensions. We find that the low modes turn from delocalized to localized as the system crosses over from the confined to the deconfined phase in the "physical" sector (positive average Polyakov loop) selected by external fermionic probes, while they remain delocalized in the "unphysical" sector (negative average Polyakov loop). This confirms that the close connection between deconfinement and localization of the low Dirac modes in the physical sector, already observed in other models, holds also in the simplest gauge theory displaying a deconfinement transition. We also observe a clear correlation of localized modes with fluctuations of the Polyakov loop away from the ordered value, as expected according to the "sea/islands" picture of localization, and with clusters of negative plaquettes. A novel finding is the presence of localized modes at the high end of the Dirac spectrum in all phases/sectors of the theory.
description: Revised version: 43 pages, 25 figures
FlingBot: The Unreasonable Effectiveness of Dynamic Manipulation for Cloth Unfolding
Creators: name: Ha, Huy
name: Song, Shuran
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences
subject: I.2.9

description: High-velocity dynamic actions (e.g., fling or throw) play a crucial role in our everyday interaction with deformable objects by improving our efficiency and effectively expanding our physical reach range. Yet, most prior works have tackled cloth manipulation using exclusively single-arm quasi-static actions, which requires a large number of interactions for challenging initial cloth configurations and strictly limits the maximum cloth size by the robot's reach range. In this work, we demonstrate the effectiveness of dynamic flinging actions for cloth unfolding with our proposed self-supervised learning framework, FlingBot. Our approach learns how to unfold a piece of fabric from arbitrary initial configurations using a pick, stretch, and fling primitive for a dual-arm setup from visual observations. The final system achieves over 80% coverage within 3 actions on novel cloths, can unfold cloths larger than the system's reach range, and generalizes to T-shirts despite being trained on only rectangular cloths. We also finetuned FlingBot on a real-world dual-arm robot platform, where it increased the cloth coverage over 4 times more than the quasi-static baseline did. The simplicity of FlingBot combined with its superior performance over quasi-static baselines demonstrates the effectiveness of dynamic actions for deformable object manipulation.
description: 11 pages, 6 figures. Code, data, and simulation environment publicly available at https://flingbot.cs.columbia.edu
Square summability with geometric weight for classical orthogonal expansions
Creators: name: Karp, D.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 30B40, 46E22

description: Let $f_k$ be the $k$-th Fourier coefficient of a function $f$ in terms of the orthonormal Hermite, Laguerre or Jacobi polynomials. We give necessary and sufficient conditions on $f$ for the inequality $\sum_{k}|f_k|^2θ^k1$. As a by-product new orthogonality relations for the Hermite and Laguerre polynomials are found. The basic machinery for the proofs is provided by the theory of reproducing kernel Hilbert spaces.
description: 11 pages
Ein vorsokratischer Vorläufer der 'materia prima': Das mittlere Element in den antiken Kommentaren zu Aristoteles
Creators: name: Marcinkowska-Rosół, Maria
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Göttinger Forum für Altertumswissenschaft, Bd. 17 (2014): Göttinger Forum für Altertumswissenschaft
Observation of B-meson decays to b_1 pi and b_1 K
Creators: name: The BABAR Collaboration
name: Aubert, B.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We present the results of searches for decays of B mesons to final states with a b_1 meson and a charged pion or kaon. The data, collected with the BaBar detector at the Stanford Linear Accelerator Center, represent 382 million B-Bbar pairs produced in e+e- annihilation. The results for the branching fractions are, in units of 10^{-6}, B(B+ -> b1^0 pi+) = 6.7 +/- 1.7 +/- 1.0 (4.0 sigma), B(B+ -> b1^0 K+ = 9.1+/- 1.7+/- 1.0 (5.3 sigma), B(B0 -> b1^-/+ pi^+/-) = 10.9 +/- 1.2 +/- 0.9 (8.9 sigma), and B(B0 -> b1^-K+) = 7.4 +/- 1.0 +/- 1.0 (6.1 sigma), with the assumption that B(b_1 -> omega pi)=1. We also measure charge and flavor asymmetries Ach(B+ -> b1^0 pi+) = 0.05 +/- 0.16 +/- 0.02, Ach(B+ -> b1^0 K+ = -0.46 +/- 0.20 +/- 0.02, Ach(B0 -> b1^-/+ pi^+/-) = -0.05 +/- 0.10 +/- 0.02, C(B0 -> b1^-/+ pi^+/-) = -0.22 +/- 0.23 +/- 0.05, deltaC(B0 -> b1^-/+ pi^+/-) = -1.04 +/- 0.23 +/- 0.08, and Ach(B0 -> b1^-K+) = -0.07 +/- 0.12 +/- 0.02, The first error quoted is statistical, the second systematic, and for the branching fractions, the significance is given in parentheses.
description: 7 pages, 1 postscript figure, as published in Physical Review Letters
Aspect-Ratio Scaling of Domain Wall Entropy for the 2D $\pm J$ Ising Spin Glass
Creators: name: Fisch, Ronald
Publisher: name: arXiv
Year: 2007
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The ground state entropy of the 2D Ising spin glass with +1 and -1 bonds is studied for $L \times M$ square lattices with $L \le M$ and $p$ = 0.5, where $p$ is the fraction of negative bonds, using periodic and/or antiperiodic boundary conditions. From this we obtain the domain wall entropy as a function of $L$ and $M$. It is found that for domain walls which run in the short, $L$ direction, there are finite-size scaling functions which depend on the ratio $M / L^{d_S}$, where $d_S = 1.22 \pm 0.01$. When $M$ is larger than $L$, very different scaling forms are found for odd $L$ and even $L$. For the zero-energy domain walls, which occur when $L$ is even, the probability distribution of domain wall entropy becomes highly singular, and apparently multifractal, as $M / L^{d_S}$ becomes large.
description: 13 pages, 7 figures; final version, to appear in J. Stat. Phys
REBCO HTS Wire Manufacturing and Continuous Development at SuperPower
Creators: name: Zhang, Yifei
name: Yamano, Satoshi
name: Hazelton, Drew
name: Fukushima, Toru
Publisher: name: Zenodo
Year: 2018

description: REBCO HTS Wire Manufacturing and Continuous Development at SuperPower. Review of recent development of HTS wires at SuperPower Inc.
Investigating a (3+1)D Topological $θ$-Term in the Hamiltonian Formulation of Lattice Gauge Theories for Quantum and Classical Simulations
Creators: name: Kan, Angus
name: Funcke, Lena
name: Kühn, Stefan
name: Dellantonio, Luca
name: Zhang, Jinglei
name: Haase, Jan F.
name: Muschik, Christine A.
name: Jansen, Karl
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum technologies offer the prospect to efficiently simulate sign-problem afflicted regimes in lattice field theory, such as the presence of topological terms, chemical potentials, and out-of-equilibrium dynamics. In this work, we derive the (3+1)D topological $θ$-term for Abelian and non-Abelian lattice gauge theories in the Hamiltonian formulation, paving the way towards Hamiltonian-based simulations of such terms on quantum and classical computers. We further study numerically the zero-temperature phase structure of a (3+1)D U(1) lattice gauge theory with the $θ$-term via exact diagonalization for a single periodic cube. In the strong coupling regime, our results suggest the occurrence of a phase transition at constant values of $θ$, as indicated by an avoided level-crossing and abrupt changes in the plaquette expectation value, the electric energy density, and the topological charge density. These results could in principle be cross-checked by the recently developed (3+1)D tensor network methods and quantum simulations, once sufficient resources become available.
description: 13 pages, 3 figures; close to journal version
Impact of plasma irradiation on Tribolium castaneum
Creators: name: Sayed, Waheed A. A.
name: Hassan, Reda S.
name: Sileem, Thanaa M.
name: Rumpold, Birgit A.
Publisher: name: Technische Universität Berlin
Year: 2021
Subjects: subject: 333.7 Natürliche Ressourcen, Energie und Umwelt
subject: He
subject: Ar
subject: gases
subject: mortality
subject: non-thermal plasma
subject: red flour beetle
subject: reproduction rate
subject: stored product pest

description: Radio frequency plasma (RFP) could provide reliable, compact, cost-effective irradiation applications against insect pests of stored food and feed products. Sensitivity of red flour beetle Tribolium castaneum to RFP has been investigated using an irradiation applicator system with the two types of inert gases, argon (Ar) and helium (He), at 100 W for five exposure time levels of 0, 20, 40, 60 and 90 s, respectively. We demonstrated that He RFP was more efficient against T. castaneum than Ar RFP. In addition, a positive correlation was observed between mortality percentages of treated insect stages and exposure times for both He and Ar RFP. The adult stage showed the highest tolerance to RFP irradiation followed by larvae and pupae; however, it was more susceptible than larvae within 24 h after He RFP treatments. The optimum exposure time was 90 s with He RFP, where a full mortality at all tested stages was accomplished, while mortalities of 71.4, 65.3 and 36.7% were recorded for pupae, larvae and adult stage, respectively, after an Ar RFP treatment of 90 s. In case of treated adults, the reproduction rate was higher than treated larvae and pupae. Our findings indicated that He RFP was an effective method for inhibiting T. castaneum development and impacting the insect life cycle and could be considered a promising tool for pest control of stored food.
Causality Constrains Higher Curvature Corrections to Gravity
Creators: name: Gruzinov, A.
name: Kleban, M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We show that causality constrains the sign of quartic Riemann corrections to the Einstein-Hilbert action. Our constraint constitutes a restriction on candidate theories of quantum gravity.
description: 5 pages
Simulating Calibration and Beam Systematics for a Future CMB Space Mission with the TOAST Package
Creators: name: Puglisi, Giuseppe
name: Keskitalo, Reijo
name: Kisner, Ted
name: Borrill, Julian D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: We address in this work the instrumental systematic errors that can potentially affect the forthcoming and future Cosmic Microwave Background experiments aimed at observing its polarized emission. In particular, we focus on the systematics induced by the beam and calibration, which are considered the major sources of leakage from total intensity measurements to polarization. We simulated synthetic data sets with Time-Ordered Astrophysics Scalable Tools, a publicly available simulation and data analysis package. We also propose a mitigation technique aiming at reducing the leakage by means of a template fitting approach. This technique has shown promising results reducing the leakage by 2 orders of magnitude at the power spectrum level when applied to a realistic simulated data set of the LiteBIRD satellite mission.
Cox rings of degree one del Pezzo surfaces
Creators: name: Testa, Damiano
name: Várilly-Alvarado, Anthony
name: Velasco, Mauricio
Publisher: name: arXiv
Year: 2008
Subjects: subject: Algebraic Geometry (math.AG)
subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics
subject: 14J26

description: Let X be a del Pezzo surface of degree one over an algebraically closed field (of any characteristic), and let Cox(X) be its total coordinate ring. We prove the missing case of a conjecture of Batyrev and Popov, which states that Cox(X) is a quadratic algebra. We use a complex of vector spaces whose homology determines part of the structure of the minimal free Pic(X)-graded resolution of Cox(X) over a polynomial ring. We show that sufficiently many Betti numbers of this minimal free resolution vanish to establish the conjecture.
description: Significant revision. Proposition 4.4 fixes gap in previous version. To appear in Algebra and Number Theory
PIERNIK MHD code: modelling propagation of cosmic ray electron population with energy spectrum in galactic disc
Creators: name: Ogrodnik, Mateusz
name: Hanasz, Michał
name: Wóltański, Dominik
Publisher: name: Zenodo
Year: 2019
Subjects: Cosmic rays, magnetic fields, galaxies, magnetohydrodynamics, numerical simulations

description: Poster presented at the conference "New Perspectives on Galactic Magnetism", that took place in Newcastle upon Tyne, 10-14 June 2019.
Discovering new forces with gravitational waves from supermassive black holes
Creators: name: Dror, Jeff A.
name: Lehmann, Benjamin V.
name: Patel, Hiren H.
name: Profumo, Stefano
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Supermassive black hole binary mergers generate a stochastic gravitational wave background detectable by pulsar timing arrays. While the amplitude of this background is subject to significant uncertainties, the frequency dependence is a robust prediction of general relativity. We show that the effects of new forces beyond the Standard Model can modify this prediction and introduce unique features into the spectral shape. In particular, we consider the possibility that black holes in binaries are charged under a new long-range force, and we find that pulsar timing arrays are capable of robustly detecting such forces. Supermassive black holes and their environments can acquire charge due to high-energy particle production or dark sector interactions, making the measurement of the spectral shape a powerful test of fundamental physics.
description: 10 pages, 3 figures. Matched published version
Hans Krämer, Gesammelte Aufsätze zu Platon
Creators: name: Jung, Christian
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Rezension zu: Hans Krämer, Gesammelte Aufsätze zu Platon. Herausgegeben von Dagmar Mirbach. Beiträge zur Altertumskunde Bd. 321. Berlin/Boston: de Gruyter 2014, XIII + 592 S.
description: Göttinger Forum für Altertumswissenschaft, Bd. 18 (2015): Göttinger Forum für Altertumswissenschaft
Modifications to the signal from a gravitational wave event due to a surrounding shell of matter
Creators: name: Naidoo, Monos
name: Bishop, Nigel T
name: van der Walt, Petrus J
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In previous work, we established theoretical results concerning the effect of matter shells surrounding a gravitational wave (GW) source, and we now apply these results to astrophysical scenarios. Firstly, it is shown that GW echoes that are claimed to be present in LIGO data of certain events, could not have been caused by a matter shell. However, it is also shown that there are scenarios in which matter shells could make modifications of order a few percent to a GW signal; these scenarios include binary black hole mergers, binary neutron star mergers, and core collapse supernovae.
description: 13 pages, 4 figures
Felix Pirson, Ansichten des Krieges. Kampfreliefs klassischer und hellenistischer Zeit im Kulturvergleich
Creators: name: Dietrich, Nikolaus
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2021

description: Rezension zu: Felix Pirson, Ansichten des Krieges. Kampfreliefs klassischer und hellenistischer Zeit im Kulturvergleich. DAI – Archäologische Forschungen Bd. 31. Wiesbaden: Reichert Verlag 2014, 408 S., 560 s/w-Abb., 60 Taf.
description: Göttinger Forum für Altertumswissenschaft, Bd. 18 (2015): Göttinger Forum für Altertumswissenschaft
First Observation of the Greisen-Zatsepin-Kuzmin Suppression
Creators: name: HiRes Collaboration
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The High Resolution Fly's Eye (HiRes) experiment has observed the Greisen-Zatsepin-Kuzmin suppression (called the GZK cutoff) with a statistical significance of five standard deviations. HiRes' measurement of the flux of ultrahigh energy (UHE) cosmic rays shows a sharp suppression at an energy of $6 \times 10^{19}$ eV, consistent with the expected cutoff energy. We observe the ``ankle'' of the cosmic-ray energy spectrum as well, at an energy of $4 \times 10^{18}$ eV. We describe the experiment, data collection, analysis, and estimate the systematic uncertainties. The results are presented and the calculation of the statistical significance of our observation is described.
description: 4 pages, 3 figures, accepted by and to appear in PRL
Quantum geometry and flat band Bose-Einstein condensation
Creators: name: Julku, Aleksi
name: Bruun, Georg M.
name: Törmä, Päivi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We study the properties of a weakly interacting Bose-Einstein condensate (BEC) in a flat band lattice system by using multiband Bogoliubov theory, and discover fundamental connections to the underlying quantum geometry. In a flat band, the speed of sound and the quantum depletion of the condensate are dictated by the quantum geometry, and a finite quantum distance between the condensed and other states guarantees stability of the BEC. Our results reveal that a suitable quantum geometry allows one to reach the strong quantum correlation regime even with weak interactions.
description: This document includes a letter "Quantum geometry and flat band Bose-Einstein condensation" and a longer article "Excitations of a Bose-Einstein condensate and the quantum geometry of a flat band". The former presents the main, and the latter the details of the calculations, considers physical quantities not studied in the letter, and provides a substantially extended discussion of the subject
Blind Motion Deblurring Super-Resolution: When Dynamic Spatio-Temporal Learning Meets Static Image Understanding
Creators: name: Niu, Wenjia
name: Zhang, Kaihao
name: Luo, Wenhan
name: Zhong, Yiran
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Single-image super-resolution (SR) and multi-frame SR are two ways to super resolve low-resolution images. Single-Image SR generally handles each image independently, but ignores the temporal information implied in continuing frames. Multi-frame SR is able to model the temporal dependency via capturing motion information. However, it relies on neighbouring frames which are not always available in the real world. Meanwhile, slight camera shake easily causes heavy motion blur on long-distance-shot low-resolution images. To address these problems, a Blind Motion Deblurring Super-Reslution Networks, BMDSRNet, is proposed to learn dynamic spatio-temporal information from single static motion-blurred images. Motion-blurred images are the accumulation over time during the exposure of cameras, while the proposed BMDSRNet learns the reverse process and uses three-streams to learn Bidirectional spatio-temporal information based on well designed reconstruction loss functions to recover clean high-resolution images. Extensive experiments demonstrate that the proposed BMDSRNet outperforms recent state-of-the-art methods, and has the ability to simultaneously deal with image deblurring and SR.
description: To appear in IEEE Transactions on Image Processing (TIP)