cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Quantum-inspired protocol for measuring the degree of similarity between spatial shapes
Creators: name: Urrego, Daniel F.
name: Torres, Juan P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We put forward and demonstrate experimentally a {\it quantum-inspired} protocol that allows to quantify the degree of similarity between two spatial shapes embedded in two optical beams without the need to measure the amplitude and phase across each beam. Instead the sought-after information can be retrieved measuring the degree of polarization of the combined optical beam, a measurement that is much easier to implement experimentally. The protocol makes use of non-separable optical beams, whose main trait is that different degrees of freedom (polarization and spatial shape here) can not be described independently.
description: 5 figures, 11 pages
Regular black holes in Verlinde's emergent gravity
Creators: name: Jusufi, Kimet
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper, we construct a class of charged and regular black hole solutions in Verlinde's Emergent Gravity (VEG). In particular, these solutions include, black holes with asymptotically Minkowski core, T-duality, Frolov/Simpson-Visser type solutions, as well as the Bardeen/Hayward type solutions as a special case. Using the relation between the apparent dark matter and the baryonic matter we find the effect of apparent dark matter on the spacetime geometry. We show that in general, the apparent dark matter leads to non-asymptotically flat spacetime geometry and, in the special limit of a point like mass distribution, all the black hole solutions in VEG resembles the global monopole-like solution with a deficit angle. To this end, we extend the solutions by including the cosmological constant (de Sitter space) and we elaborate different energy conditions of black hole solutions. Finally, having in mind that the Einstein's field equation are not modified in this theory while the apparent dark matter is encoded in the energy-momentum tensor, we used the modified Newman--Janis-Azreg-Aïnou algorithm to obtain the corresponding effective rotating metrics.
description: Accepted for publication in Annals of Physics
Anomalous Josephson current through a driven double quantum dot
Creators: name: Ortega-Taberner, Carlos
name: Jauho, Antti-Pekka
name: Paaske, Jens
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Josephson junctions based on quantum dots offer a convenient tunability by means of local gates. Here we analyze a Josephson junction based on a serial double quantum dot in which the two dots are individually gated by phase-shifted microwave tones of equal frequency. We calculate the time-averaged current across the junction and determine how the phase shift between the drives modifies the current-phase relation of the junction. Breaking particle-hole symmetry on the dots is found to give rise to a finite average anomalous Josephson current with phase bias between the superconductors fixed to zero. This microwave gated weak link thus realizes a tunable "Floquet $φ_{0}$-junction" with maximum critical current achieved for driving frequencies slightly off-resonance with the energy cost of exciting a sub-gap state on each dot. We provide numerical results supported by an analytical analysis for infinite superconducting gap and weak inter-dot coupling. We identify an interaction driven $0-π$ transition of anomalous Josephson current as a function of driving phase difference. Finally, we show that this junction can be tuned so as to provide for complete rectification of the time-averaged Josephson current phase relation.
description: 16 pages, 12 figures
Probing the initial state of inflation: analytical structure of cosmological correlators
Creators: name: Ghosh, Diptimoy
name: Singh, Amartya Harsh
name: Ullah, Farman
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the analytic structure of in-in correlation functions in a deSitter background. The aim of this study is to probe the initial conditions for inflation through the features of correlation functions of the field fluctuations, and understand precisely how an in-in correlator responds to particles in the initial state. We emphasize that the choice of vacuua and the corresponding particle interpretation for these fluctuations is flexible, and we clarify the role of this choice at the level of calculations and their diagrammatic interpretation. We consider several possibilities aside from the standard Bunch Davies vacuum prescription for the initial state, and trace the change in pole structure as one begins adding excitations; starting from just a single particle, to highly excited states and special cases such as a coherent state. We illustrate - with the example of coherent states - the subtleties in concluding a Bunch Davies initial state from the absence of physical poles in the bispectrum, which is interesting in light of some recent literature. Initial states with a finite number of excitations are plagued with disconnected diagrams isolated in phase space, and we highlight their implications on the observation of these signals, and how the situation changes as one begins to excite more and more particles. We also comment about the implications of various initial conditions on the squeezed limit of the bispectrum. These new pole structures are a direct consequence of mixing of positive and negative frequency modes which is a characteristic of curved spacetimes; in particular, we see in detail how particles in an initial state replicate mode mixing structures. This study aims to clarify the missing details that link quantum and classical initial conditions, and sharpen our understanding of in-in correlators in inflation.
description: 46 pages, typos corrected, sections have been slightly rearranged, no changes in the main results
Generalized Coupling Parameter Expansion: Application to Square-Well and Lennard Jones Fluids
Creators: name: Ramana, A. Sai Venkata
Publisher: name: arXiv
Year: 2013
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The coupling parameter expansion in thermodynamic perturbation theory of simple fluids is generalized to include the derivatives of bridge function. We applied seventh order version of the theory to Square-Well (SW) and Lennard-Jones (LJ) fluids using Sarkisov Bridge function. In both cases, the theory reproduced the radial distribution functions obtained from integral equation theory (IET) and simulations with good accuracy. Also, the method worked inside the liquid-vapor coexistence region where the IETs are known to fail. In the case of SW fluids, the use of Carnahan-Starling expression for free energy density of Hard-Sphere reference system has improved the liquid-vapor phase diagram (LVPD) over that obtained from IET. We also obtained the surface tension of SW fluids of various ranges. Results of present theory and simulations are in good agreement. In the case of LJ fluids, the equation of state obtained from the present method matched with that obtained from IET with negligible deviation. We also obtained LVPD of LJ fluid from virial and energy routes and found that there is slight inconsistency between the two routes. The applications lead to the following conclusions. In cases where reference system properties are known accurately, the present method gives results which are very much improved over those obtained from the IET with the same bridge function. In cases where reference system data is not available, the method serves as an alternative way of solving the Ornstein-Zernike equation with a given closure relation with the advantage that solution can be obtained throughout the phase diagram with a proper choice of the reference system.
description: 18 pages, 8 figures. Minor revision has been made
Duden. Die deutsche Rechtschreibung
Creators: name: Werner, Jürgen
Publisher: name: Forum Classicum
Year: 2017

description: Rezension zu: Duden. Die deutsche Rechtschreibung. 22., völlig neub. und erw. Aufl. Mannheim usw. (Dudenverlag) 2000. Der Duden in zwölf Bänden 1. 1152 S. ISBN 3-411-04012-2. PC-Bibliothek Version 2.1 mit Plus-Paket: Duden - die deutsche Rechtschreibung. 1 CD-ROM für Windows oder Apple Macintosh. Mannheim usw. (Dudenverlag) 2000. (ISBN 3-411-06706-3).
description: Forum Classicum, Nr. 3 (2000): Forum Classicum
Boundary Effects on Ideal Fluid Forces and Kelvin's Minimum Energy Theorem
Creators: name: McKee, Kyle
Publisher: name: arXiv
Year: 2022
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The electrostatic force on a charge above a neutral conductor is generally attractive. Surprisingly, that force becomes repulsive in certain geometries (Levin & Johnson 2011), a result that follows from an energy theorem in electrostatics. Based on the analogous minimum energy theorem of Kelvin (1849), valid in the theory of ideal fluids, we show corresponding effects on steady and unsteady fluid forces in the presence of boundaries. Two main results are presented regarding the unsteady force. First, the added mass is proven to always increase in the presence of boundaries. Second, in a model of a body approaching a boundary, where the unsteady force is typically repulsive (Lamb 1975, §137), we present a geometry where the force can be attractive. As for the steady force, there is one main result: in a model of a Bernoulli suction gripper, for which the steady force is typically attractive, we show that force becomes repulsive in some geometries. Both the unsteady and steady forces are shown to reverse sign when boundaries approximate flow streamlines, at energy minima predicted by Kelvin's theorem.
Fossil group origins XII. Large-scale environment around fossil systems
Creators: name: Zarattini, S.
name: Aguerri, J. A. L.
name: Calvi, R.
name: Girardi, M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We analyse the large-scale structure out to 100 Mpc around a sample of 16 confirmed fossil systems using spectroscopic information from the Sloan Digital Sky Survey Data Release 16. We compute the distance between our FGs and the centres of filaments and nodes presented in \citet{Chen2016}. We also study the density of bright galaxies, since they are thought to be good mass tracers, and the projected over densities of galaxies. Finally, we apply a FoF algorithm to detect virialised structures around our FGs, in order to have an estimate of the mass available in their surroundings. FGs are mainly found close to filaments, with a mean distance of $3.7 \pm 1.1$ R$_{200}$ and a minimum distance of 0.05 $R_{200}$. On the other hand, none of our FGs is found close to intersections, with a mean and minimum distance of $19.3 \pm 3.6$ and 6.1 $R_{200}$, respectively. There is a correlation for which FGs at higher redshifts are found in denser regions, when we use bright galaxies as tracers of the mass. At the same time, FGs with the largest magnitude gaps ($Δm_{12}$ > 2.5) are found in less dense environments and hosting, on average, smaller central galaxies. Our results suggest that FGs formed in a peculiar position of the cosmic web, close to filaments and far from nodes, in which their interaction with the cosmic web itself can be limited. We deduce that FGs with faint BCGs, large $Δm_{12}$, and low redshifts could be systems at the very last stage of their evolution. Moreover, we confirm theoretical predictions that systems with the largest magnitude gap are not massive.
description: 23 pages, 10 figures, and 2 tables. Accepted for publication on Astronomy and Astrophysics
Obstacles for splitting multidimensional necklaces
Creators: name: Lasoń, Michał
Publisher: name: arXiv
Year: 2013
Subjects: subject: Combinatorics (math.CO)
subject: General Topology (math.GN)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 05D99, 54H99, 12E99, 52C45

description: The well-known "necklace splitting theorem" of Alon asserts that every $k$-colored necklace can be fairly split into $q$ parts using at most $t$ cuts, provided $k(q-1)\leq t$. In a joint paper with Alon et al. we studied a kind of opposite question. Namely, for which values of $k$ and $t$ there is a measurable $k$-coloring of the real line such that no interval has a fair splitting into $2$ parts with at most $t$ cuts? We proved that $k>t+2$ is a sufficient condition (while $k>t$ is necessary). We generalize this result to Euclidean spaces of arbitrary dimension $d$, and to arbitrary number of parts $q$. We prove that if $k(q-1)>t+d+q-1$, then there is a measurable $k$-coloring of $\mathbb{R}^d$ such that no axis-aligned cube has a fair $q$-splitting using at most $t$ axis-aligned hyperplane cuts. Our bound is of the same order as a necessary condition $k(q-1)>t$ implied by a theorem of Alon. Moreover for $d=1,q=2$ we get exactly the result of of Alon et al. Additionally, we prove that if a stronger inequality $k(q-1)>dt+d+q-1$ is satisfied, then there is a measurable $k$-coloring of $\mathbb{R}^d$ with no axis-aligned cube having a fair $q$-splitting using at most $t$ arbitrary hyperplane cuts. The proofs are based on the topological Baire category theorem and use algebraic independence over suitably chosen fields.
description: final version, 14 pages
Gleason and Bishop
Creators: name: (:Unav)
Publisher: name: Columbia University
Year: 2019

description: Lords of Contemporary Society. Mike Rod on saxophone, Buddy Prima on piano, Andrew Muzon on bass guitar and Lenny Seed on drums play jazz live in studio, "Little by Little" Rolling Stones, spoken word song about utilities in the city, Rod, Prima, Muzon, and Seed play more, Fass takes calls for pun names for a woman named Clair, Tell Me Who I'll Marry by Judy Collins, Fass mentions Tarzan movie in theaters, "The Lily of the West" Joan Baez, "Grizzly Bear" the Youngbloods, "Hard Loving Loser" Judy Collins, "She Belongs to Me" Bob Dylan, instrumental music plays, "Monkeyin' Around" Jake Jones and the Gold Front Boys 1929
Reconstruction of Inert Doublet Scalars at the International Linear Collider
Creators: name: Aoki, Mayumi
name: Kanemura, Shinya
name: Yokoya, Hiroshi
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We study collider signatures for extra scalar bosons in the inert doublet model at the international linear collider (ILC). The inert doublet model is a simple extension of the standard model by introducing an additional isospin-doublet scalar field which is odd under an unbroken Z_2 symmetry. The model predicts four kinds of Z_2-odd scalar bosons, and the lightest of them becomes stable and a candidate of the dark matter as long as it is electrically neutral. Taking into account the constraints from various theoretical and phenomenological conditions, we perform a simulation study for the distinctive signatures of the extra scalars over the standard-model background contributions at the ILC with the center-of-mass energy of sqrt{s} = 250 GeV and 500 GeV. We further discuss observables for determination of the mass of the scalars. We find that the parameter regions which cannot be detected at the large hadron collider can be probed at the ILC.
description: 18 pages, 12 figures; comments added, references added, version to be published
Quantum Hall valley Ferromagnets as a platform for topologically protected quantum memory
Creators: name: Agarwal, Kartiek
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Materials hosting topologically protected non-Abelian zero modes offer the exciting possibility of storing and manipulating quantum information in a manner that is protected from decoherence at the hardware level. In this work, we study the possibility of realizing such excitations along line defects in certain fractional quantum Hall states in multi-valley systems. Such line defects have been recently observed experimentally between valley polarized Hall states on the surface of Bi(111), and excitations near these defects appear to be gapped (gapless) depending on the presence (absence) of interaction-induced gapping perturbations constrained by momentum selection rules, while the position of defects is determined by strain. In this work, we use these selection rules to show that a hybrid structure involving a superlattice imposed on such a multi-valley quantum Hall surface realizes non-Abelian anyons which can then be braided by modulating strain locally to move line defects. Specifically, we explore such defects in Abelian fractional quantum Hall states of the form ν = 2/m using a K-matrix approach, and identify relevant gapping perturbations. Charged modes on these line defects remain gapped, while charge netural valley pseudospin modes may be gapped with the aid of two (mutually orthogonal) superlattices which pin non-commuting fields. When these superlattices are alternated along the line defect, non-Abelian zero modes result at points where the gapping perturbation changes. Given that these pseudospin modes carry no net physical charge or spin, the setup eschews utilizing superconducting and magnetic elements to engineer gapping perturbations. We provide a scheme to braid these modes using strain modulation, and confirm that the resulting unitaries satisfy a representation of the braid group.
description: 20 pages, 3 figures; comments welcome
Hose, Martin: Kleine griechische Literaturgeschichte. Von Homer bis zum Ende der Antike
Creators: name: Wölke, Hansjörg
Publisher: name: Forum Classicum
Year: 2017

description: Rezension zu: Hose, Martin: Kleine griechische Literaturgeschichte. Von Homer bis zum Ende der Antike. München: Beck 1999. 261 S. (Becksche Reihe. 1326; ISBN 3-406-42126-1).
description: Forum Classicum, Nr. 3 (2000): Forum Classicum
Plasma lensing near the eclipses of the Black Widow pulsar B1957+20
Creators: name: Lin, Fang Xi
name: Main, Robert
name: Jow, Dylan
name: Li, Dongzi
name: Pen, Ue-Li
name: van Kerkwijk, Marten H.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Recently, several eclipsing millisecond pulsars have been shown to experience strong and apparent weak lensing from the outflow of their ionized companions. Lensing can be a powerful probe of the ionized plasma, with the strongest lenses potentially resolving emission regions of pulsars. Understanding lensing in the `laboratory-like' conditions of an eclipsing pulsar may be analogously applied to fast radio bursts, many of which reside in dense, magnetized environments. We examined variable dispersion measure (DM), absorption, scattering, and flux density in the original Black Widow pulsar PSR B1957+20 through an eclipse at the Arecibo Observatory at 327 MHz. We discovered clear evidence of the two regimes of lensing, strong and apparent weak. We show that the flux density variations in the apparently weak lensing regime can be modeled directly from variations of DM, using geometric optics. The mean effective velocities in the ingress, $954\pm 99$ km/s, and egress $604\pm 47$ km/s cannot be explained by orbital motions alone, but are consistent with significant outflow velocity of material from the companion. We also show that geometric optics can predict when and where the lensing regime-change between weak and strong occurs, and argue that the apparent weak lensing is due to averaging many images. Our framework can be applied in any source with variable electron columns, measuring their relative velocities and distances. In other eclipsing pulsars, this provides a unique opportunity to measure companion outflow velocity, predict regions of weak and strong lensing, and in principle independently constrain orbital inclinations.
description: 15 pages, 9 figures, 1 table, accepted to MNRAS; v3 journal accepted version
Preparing Valence-Bond-Solid states on noisy intermediate-scale quantum computers
Creators: name: Murta, Bruno
name: Cruz, Pedro M. Q.
name: Fernández-Rossier, J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Quantum state preparation is a key step in all digital quantum simulation algorithms. Here we propose methods to initialize on a gate-based quantum computer a general class of quantum spin wave functions, the so-called Valence-Bond-Solid (VBS) states, that are important for two reasons. First, VBS states are the exact ground states of a class of interacting quantum spin models introduced by Affleck, Kennedy, Lieb and Tasaki (AKLT). Second, the two-dimensional VBS states are universal resource states for measurement-based quantum computing. We find that schemes to prepare VBS states based on their tensor-network representations yield quantum circuits that are too deep to be within reach of noisy intermediate-scale quantum (NISQ) computers. We then apply the general non-deterministic method herein proposed to the preparation of the spin-1 and spin-3/2 VBS states, the ground states of the AKLT models defined in one dimension and in the honeycomb lattice, respectively. Shallow quantum circuits of depth independent of the lattice size are explicitly derived for both cases, making use of optimization schemes that outperform standard basis gate decomposition methods. Given the probabilistic nature of the proposed routine, two strategies that achieve a quadratic reduction of the repetition overhead for any VBS state defined on a bipartite lattice are devised. Our approach should permit to use NISQ processors to explore the AKLT model and variants thereof, outperforming conventional numerical methods in the near future.
description: Main text: 17 pages, 7 figures. Appendices: 10 pages, 5 figures. QASM files to be added in next version of preprint
A comprehensive analysis of the compact phase space for Hu-Sawicki $f(R)$ dark energy models including spatial curvature
Creators: name: MacDevette, Kelly
name: Dunsby, Peter
name: Chakraborty, Saikat
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present a comprehensive dynamical systems analysis of homogeneous and isotropic Friedmann-Laîmatre-Robertson-Walker cosmologies in the Hu-Sawicki $f(R)$ dark energy model for the parameter choice $\{n,C_1\}=\{1,1\}$. For a generic $f(R)$ theory, we outline the procedures of compactification of the phase space, which in general is 4-dimensional. We also outline how, given an $f(R)$ model, one can determine the coordinate of the phase space point that corresponds to the present day universe and the equation of a surface in the phase space that represents the $Λ$CDM evolution history. Next, we apply these procedures to the Hu-Sawicki model under consideration. We identify some novel features of the phase space of the model such as the existence of invariant submanifolds and 2-dimensional sheets of fixed points. We determine the physically viable region of the phase space, the fixed point corresponding to possible matter dominated epochs and discuss the possibility of a non-singular bounce, re-collapse and cyclic evolution. We also provide a numerical analysis comparing the $Λ$CDM evolution and the Hu-Sawicki evolution.
description: 23 pages, 9 figures
The Wald entropy formula and loop quantum gravity
Creators: name: Bodendorfer, Norbert
name: Neiman, Yasha
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We outline how the Wald entropy formula naturally arises in loop quantum gravity based on recently introduced dimension-independent connection variables. The key observation is that in a loop quantization of a generalized gravity theory, the analog of the area operator turns out to measure, morally speaking, the Wald entropy rather than the area. We discuss the explicit example of (higher-dimensional) Lanczos-Lovelock gravity and comment on recent work on finding the correct numerical prefactor of the entropy by comparing it to a semiclassical effective action.
description: 23 pages. v2: journal version. Details added, discussion clarified
Weinlich, Barbara; Ovids Amores. Gedichtfolge und Handlungsablauf
Creators: name: Lobe, Michael
Publisher: name: Forum Classicum
Year: 2017

description: Rezension zu: Weinlich, Barbara; Ovids Amores. Gedichtfolge und Handlungsablauf. Stuttgart, Leipzig: Teubner 1999. 295 S. (Beiträge zur Altertumskunde. 128; ISBN 3-598-77677-2).
description: Forum Classicum, Nr. 3 (2000): Forum Classicum
Calibration-Aware Transpilation for Variational Quantum Optimization
Creators: name: Ji, Yanjun
name: Brandhofer, Sebastian
name: Polian, Ilia
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Today's Noisy Intermediate-Scale Quantum (NISQ) computers support only limited sets of available quantum gates and restricted connectivity. Therefore, quantum algorithms must be transpiled in order to become executable on a given NISQ computer; transpilation is a complex and computationally heavy process. Moreover, NISQ computers are affected by noise that changes over time, and periodic calibration provides relevant error rates that should be considered during transpilation. Variational algorithms, which form one main class of computations on NISQ platforms, produce a number of similar yet not identical quantum ``ansatz'' circuits. In this work, we present a transpilation methodology optimized for variational algorithms under potentially changing error rates. We divide transpilation into three steps: (1) noise-unaware and computationally heavy pre-transpilation; (2) fast noise-aware matching; and (3) fast decomposition followed by heuristic optimization. For a complete run of a variational algorithm under constant error rates, only step (3) needs to be executed for each new ansatz circuit. Step (2) is required only if the error rates reported by calibration have changed significantly since the beginning of the computation. The most expensive Step (1) is executed only once for the whole run. This distribution is helpful for incremental, calibration-aware transpilation when the variational algorithm adapts its own execution to changing error rates. Experimental results on IBM's quantum computer show the low latency and robust results obtained by calibration-aware transpilation.
description: Accepted by QCE22 (2022 IEEE International Conference on Quantum Computing & Engineering (QCE))
A Bayesian approach for predicting the popularity of tweets
Creators: name: Zaman, Tauhid
name: Fox, Emily B.
name: Bradlow, Eric T.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Social and Information Networks (cs.SI)
subject: Physics and Society (physics.soc-ph)
subject: Applications (stat.AP)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: We predict the popularity of short messages called tweets created in the micro-blogging site known as Twitter. We measure the popularity of a tweet by the time-series path of its retweets, which is when people forward the tweet to others. We develop a probabilistic model for the evolution of the retweets using a Bayesian approach, and form predictions using only observations on the retweet times and the local network or "graph" structure of the retweeters. We obtain good step ahead forecasts and predictions of the final total number of retweets even when only a small fraction (i.e., less than one tenth) of the retweet path is observed. This translates to good predictions within a few minutes of a tweet being posted, and has potential implications for understanding the spread of broader ideas, memes, or trends in social networks.
description: Published in at http://dx.doi.org/10.1214/14-AOAS741 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org)
New Variables for Classical and Quantum Gravity in all Dimensions V. Isolated Horizon Boundary Degrees of Freedom
Creators: name: Bodendorfer, Norbert
name: Thiemann, Thomas
name: Thurn, Andreas
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In this paper, we generalise the treatment of isolated horizons in loop quantum gravity, resulting in a Chern-Simons theory on the boundary in the four-dimensional case, to non-distorted isolated horizons in 2(n+1)-dimensional spacetimes. The key idea is to generalise the four-dimensional isolated horizon boundary condition by using the Euler topological density of a spatial slice of the black hole horizon as a measure of distortion. The resulting symplectic structure on the horizon coincides with the one of higher-dimensional SO(2(n+1))-Chern-Simons theory in terms of a Peldan-type hybrid connection and resembles closely the usual treatment in 3+1 dimensions. We comment briefly on a possible quantisation of the horizon theory. Here, some subtleties arise since higher-dimensional non-Abelian Chern-Simons theory has local degrees of freedom. However, when replacing the natural generalisation to higher dimensions of the usual boundary condition by an equally natural stronger one, it is conceivable that the problems originating from the local degrees of freedom are avoided, thus possibly resulting in a finite entropy.
description: 49 pages. v2. journal version. Reference added
\textit{Ab initio} study on spin fluctuations of itinerant kagome magnet FeSn
Creators: name: Zhang, Yi-Fan
name: Ni, Xiao-Sheng
name: Datta, Trinanjan
name: Wang, Meng
name: Yao, Dao-Xin
name: Cao, Kun
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Kagome antiferromagnetic metal FeSn has become an attracting platform for the exploration of novel electronic states, such as topological Dirac states and the formation of flat bands by localized electrons. Apart from the electronic properties, Dirac magnons and flat magnon bands have also been proposed by applying simplified Heisenberg models to kagome magnetic systems.Inelastic neutron scattering studies on FeSn found well defined magnon dispersions at low energies,but magnons at high energies are strongly dampled, which can not be explained by localized spin models. In this paper, we utilize both linear spin wave theory and time-dependent density functional perturbation theory to investigate spin fluctuations of FeSn. Through the comparison of calculated spin wave spectra and Stoner continuum, we explicitly show that the damping of magnons at high energies are due to the Landau damping, and the appearance of high energy optical-magnon like branches at the M and K point are resulted by relatively low Stoner excitation intensity at those regions.
Gauge/Gravity Duality in Heterotic String Theory
Creators: name: Chen, Fang
name: Dasgupta, Keshav
name: Lapan, Joshua M.
name: Seo, Jihye
name: Tatar, Radu
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Gravity duals for little string theories --- which give rise to four-dimensional theories that undergo permanent confinement in the infrared --- have not been studied in great detail. We address this question in the framework of heterotic SO(32) and E_8 x E_8 string theory, constructing these backgrounds by wrapping heterotic five-branes on calibrated two-cycles of non-Kahler resolved conifolds. Related to deformations of the underlying little string theories, we find numerous analytic solutions preserving N = 1 supersymmetry in four-dimensions. These theories all have non-abelian global symmetries that generally arise from both the heterotic vector bundle and from certain orbifold states. In the decoupling limit, we argue that the gravity duals are given by non-Kahler manifolds that have both blown-up two-cycles and three-cycles at the origin. We argue this following certain duality sequences that include M-theory torsional manifolds at an intermediate step, which help us to construct new type I' gauge/gravity duality pairs. In the M-theory duality frame, we also elucidate new sequences of flips and flops.
description: 69 pages, 15 eps figures, LaTeX JHEP style; v2: Some sections expanded, tables and typos fixed and references updated; v3: Typos corrected, references and a new appendix added. Final version to appear in Phys. Rev D
Labor Market Demographic Change and White Worker Reactions to Pro-Diversity Language
Creators: name: Hurst, Reuben
Publisher: name: OSF Registries
Year: 2020
Subjects: subject: Social and Behavioral Sciences

description: This project consider the possibility that growing labor market diversity generates aversion among traditionally dominant social groups (i.e. white workers in the United States) towards firms who espouse pro-diversity beliefs. It tests this theory with a survey experiment.
New formalism to define vacuum states for scalar fields in curved space-times
Creators: name: Penna-Lima, Mariana
name: Pinto-Neto, Nelson
name: Vitenti, Sandro D. P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The problem of finding a vacuum definition for a single quantum field in curved space-times is discussed under a new geometrical perspective. The phase space dynamics of the quantum field modes are mapped to curves in a 2-dimensional hyperbolic metric space, in which distances between neighbor points are shown to be proportional to the Bogoliubov coefficients associated with their corresponding mode solutions in phase space. The vacuum state for each mode is then defined as the unique trajectory from which all mapped phase space solutions move within thin annular regions around it. This property implies the stability of the vacuum state: solutions evolved from a point in this trajectory stay close to it as both evolve, and the particle creation is therefore minimized. The new approach is applied to the well-known cases of the time-independent dynamics, where the solutions draw circles around this curve, and when the adiabatic approximation is valid. The analysis is then extended to time-dependent cases in which the adiabatic approximation is not applicable, in the super-Hubble or low-frequency regimes. It is shown that stability trajectories can also be found in these situations, and stable quantum vacua can be obtained. This new formalism is applied to two situations: de Sitter space, where the Bunch-Davies vacuum is obtained in a completely different manner through an analysis in the super-Hubble regime, and in the context of cosmological bouncing models, in which the contracting phase is dominated by a cosmological constant in the asymptotic past. A new vacuum state for cosmological perturbations is proposed in this situation.
description: 31 pages, 6 figures
$H\to γγ$ to all orders in $α_s$ in the large-$β_0$ limit of QCD
Creators: name: Boito, D.
name: Neves, G. das
name: Piclum, J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this note, we present the result for the QCD corrections to the decay of the Higgs boson into two photons in the large-$β_0$ limit of QCD, providing the first two terms in the heavy-top expansion. From our results, one can easily read off the exact leading-$n_f$ QCD contributions in analytic form to all orders in the strong coupling, $α_s$, where $n_f$ is the number of massless quarks, and identify the leading renormalon singularities. We give explicit results for the leading-$n_f$ coefficients at 6 and 7 loops and use the large-$β_0$ result to speculate about the size of yet unknown (but small) higher-order contributions to the QCD series.
description: 15 pages, 3 figures. Extended results to include the first two terms in the heavy-top expansion. Matches published version
Analytical modelling of adaptive optics systems: Role of the influence function
Creators: name: Berdeu, Anthony
name: Tallon, Michel
name: Thiébaut, Éric
name: Langlois, Maud
Publisher: name: arXiv
Year: 2023
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Context. Adaptive optics (AO) is now a tool commonly deployed in astronomy. The real time correction of the atmospheric turbulence that AO enables allows telescopes to perform close to the diffraction limit at the core of their point spread function (PSF). Among other factors, AO-corrected PSFs depend on the ability of the wavefront corrector (WFC), generally a deformable mirror, to fit the incident wavefront corrugations. Aims. In this work, we focus on this error introduced by the WFC, the so-called fitting error. To date, analytical models only depend on the WFC cut-off frequency, and Monte Carlo simulations are the only solution for studying the impact of the WFC influence function shape on the AO-corrected PSF. We aim to develop an analytical model accounting for the influence function shape. Methods. We first obtain a general analytical model of the fitting error structure function. With additional hypotheses, we then derive an analytical model of the AO-corrected power spectral density. These two analytical solutions are compared with Monte Carlo simulations on different ideal profiles (piston, pyramid, Gaussian) as well as with real hardware (DM192 from ALPAO). Results. Our analytical predictions show a very good agreement with the Monte Carlo simulations. We show that in the image plane, the depth of the correction as well as the transition profile between the AO-corrected area and the remaining turbulent halo depend on the influence functions of the WFC. We also show that the generally assumed hypothesis of stationarity of the AO correction is actually not met. Conclusions. As the fitting error is the intrinsic optimal limit of an AO system, our analytical model allows for the assessment of the theoretical limits of extreme AO systems limited by the WFC in high-contrast imaging through a context where other errors become comparable.
Stark-chirped rapid adiabatic passage in the presence of dissipation for quantum computation
Creators: name: Shi, X.
name: Oh, C. H.
name: Wei, L. F.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Stark-chirped rapid adiabatic passage (SCRAP) is an important technique used for coherent quantum controls. In this paper we investigate how the practically-existing dissipation of the system influences on the efficiency of the passage, and thus the fidelities of the SCRAP-based quantum gates. With flux-biased Josephson qubits as a specifical example, our results show clearly that the efficiency of the logic gates implemented by SCRAP are robust against the weak dissipation. The influence due to the non-adiabtic transitions between the adiabatic passages is comparatively significantly small. Therefore, the SCRAP-based logic gates should be feasible for the realistic physical systems with noises.
Well balanced finite volume schemes for shallow water equations on manifolds
Creators: name: Carlino, Michele Giuliano
name: Gaburro, Elena
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: In this paper we propose a novel second-order accurate well balanced scheme for shallow water equations in general covariant coordinates over manifolds. In our approach, once the gravitational field is defined for the specific case, one equipotential surface is detected and parametrized by a frame of general covariant coordinates. This surface is the manifold whose covariant parametrization induces a metric tensor. The model is then re-written in a hyperbolic form with a tuple of conserved variables composed both of the evolving physical quantities and the metric coefficients. This formulation allows the numerical scheme to automatically compute the curvature of the manifold as long as the physical variables are evolved.
Feeding in the first 1000 days among infants with Down syndrome: A scoping review
Creators: name: Clarke, Emily
name: Grigg, Karen
name: Worrell, Courtney
name: Agrawal, Seema
name: Scothorn, Rebecca
name: Wasser, Heather
name: Thompson, Kelsey
name: Willis, Erik
Publisher: name: OSF Registries
Year: 2023
Subjects: subject: Other Rehabilitation and Therapy
subject: Maternal and Child Health
subject: Speech Pathology and Audiology
subject: Public Health
subject: Nutrition
subject: Medicine and Health Sciences
subject: Life Sciences
subject: Communication Sciences and Disorders
subject: Rehabilitation and Therapy
subject: Social and Behavioral Sciences

description: This scoping review aimed to 1) comprehensively describe the extent to which infants with Down Syndrome are fed according to recommended guidelines (AAP/DGA, WHO, ESPGHAN) during the first 1000 days (birth to 36 months), inclusive of what and how infants are fed, and 2) to characterize factors associated with meeting these guidelines.
Bayern und die Antike. 150 Jahre Maximilians-Gymnasium München, herausgegeben von Wolf-Arnim Frhr. V. Reitzenstein
Creators: name: Rabl, Josef
Publisher: name: Forum Classicum
Year: 2017

description: Rezension zu: Bayern und die Antike. 150 Jahre Maximilians-Gymnasium München, herausgegeben von Wolf-Arnim Frhr. V. Reitzenstein, Verlag C.H.Beck, München 1999, 331 Seiten (ISBN 3 406 44995 6).
description: Forum Classicum, Nr. 3 (2000): Forum Classicum
Ekkehard Stärk: Kleine Schriften zur römischen Literatur. Hrsg. v. Ursula Gärtner, Eckard Lefèvre und Kurt Sier
Creators: name: Werner, Jürgen
Publisher: name: Forum Classicum
Year: 2017

description: Rezension zu: Ekkehard Stärk: Kleine Schriften zur römischen Literatur. Hrsg. v. Ursula Gärtner, Eckard Lefèvre und Kurt Sier. Tübingen (Gunter Narr Verlag) 2005 (Leipziger Studien zur Klassischen Philologie 2). 362 S. ISBN3-8233-5982-7.
description: Forum Classicum, Nr. 1 (2009): Forum Classicum
Ultramassive black holes formed by triple quasar mergers at $z\sim 2$
Creators: name: Ni, Yueying
name: DiMatteo, Tiziana
name: Chen, Nianyi
name: Croft, Rupert
name: Bird, Simeon
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The origin of rare and elusive ultramassive black holes (UMBH, with MBH > 1e10 Msun) is an open question. Using the large volume cosmological hydrodynamic simulation ASTRID, we report on the formation of an extremely massive UMBH with MBH ~ 1e11 Msun at z~2. The UMBH is assembled as a result of two successive mergers of massive galaxies each with stellar mass M* > 3e11 Msun that also produces a bright, rare triple quasar system powered by three ~10^9 Msun black holes. The second merger of supermassive black holes (SMBHs) follows the first after 150 Myrs. The merger events lead to sustained Eddington accretion onto the central SMBH, forming an UMBH in the center of a massive compact stellar core with M* > 2e12 Msun. The strong feedback of the UMBH quenches the surrounding star formation to < 10 Msun/yr in the inner 50 kpc/h region. There are two more UMBHs with MBH > 5e10 Msun at z>2 in ASTRID which are also produced by major mergers of galaxies, and their progenitors can be observed as quasar triplets of lower luminosity. The rarely observed quasar multiples can be the cradle of UMBHs at high redshift, and likely end up in the center of the most massive clusters.
description: 7 pages, 4 figures, comments welcome
A $U$-Spin Anomaly in Charm CP Violation
Creators: name: Schacht, Stefan
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Recent LHCb data shows that the direct CP asymmetries of the decay modes $D^0\rightarrow π^+π^-$ and $D^0\rightarrow K^+K^-$ have the same sign, violating an improved $U$-spin limit sum rule in an unexpected way at $2.1σ$. From the new data, we determine for the first time the imaginary part of the CKM-subleading, $U$-spin breaking $ΔU=1$ correction to the $U$-spin limit $ΔU=0$ amplitude. The imaginary part of the $ΔU=0$ amplitude is determined by $Δa_{CP}^{\mathrm{dir}}$. The corresponding strong phases are yet unknown and could be extracted in the future from time-dependent measurements. Assuming $\mathcal{O}(1)$ strong phases due to non-perturbative rescattering, we find the ratio of $U$-spin breaking to $U$-spin limit contributions to the CKM-subleading amplitudes to be $(173^{+85}_{-74})\%$. This highly exceeds the Standard Model (SM) expectation of $\sim 30\%$ $U$-spin breaking, with a significance of $1.95σ$. If this puzzle is confirmed with more data in the future, in the SM it would imply the breakdown of the $U$-spin expansion in CKM-subleading amplitudes of charm decays. The other solution are new physics models that generate an additional $ΔU=1$ operator, leaving the $U$-spin power expansion intact. Examples for the latter option are an extended scalar sector or flavorful $Z'$ models.
description: 20 pages. Matches published version
Optimal time-decay estimates for a diffusive Oldroyd-B model
Creators: name: Wang, Yinghui
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35Q35, 76A10, 74H40

description: In this paper, we study the optimal time decay rates for the higher order spatial derivatives of solutions to a diffusive Oldroyd-B model. As pointed out in the Section 1.2 of Huang-Wang-Wen-Zi (J. Differential Equations 306: 456-491, 2022), how to estiblish the optimal decay estimate for the highest-order spatial derivatives of the solution to this model is still an open problem. Motivated by Wang-Wen (Sci. China Math. 65: 1199-1228, 2022), we give a positive answer to this problem via some delicate analyses on the low and high frequency parts of the solution.
description: A revised version with more details