cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Transitivity and the existence of horseshoes on the 2-torus
Creators: name: Nunes, Pollyanna Vicente
name: Tal, Fabio Armando
Publisher: name: arXiv
Year: 2022
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 37E30, 37E45, 37B40

description: We study the relationship between transitivity and topological chaos for homeomorphisms of the two torus. We show that if a transitive homeomorphism of $\mathbb{T}^2$ is homotopic to the identity and has both a fixed point and a periodic point which is not fixed, then it has a topological horseshoe. We also show that if a transitive homeomorphims of $\mathbb{T}^2$ is homotopic to a Dehn twist, then either it is aperiodic or it has a topological horseshoe.
description: To appear in Nonlinearity
Dal bue al bronzo? L’“evoluzione” degli strumenti monetali nella Roma arcaica e il caso dei sistemi di ammende pecuniarie fino alla fine del V secolo a.C.
Creators: name: Viglietti, Cristiano
Publisher: name: HISTORIKA Studi di storia greca e romana
Year: 2022

description: Il saggio affronta il tema dell'evoluzione degli strumenti “monetali” a Roma in età arcaica, con un’attenzione particolare alle forme di pagamento di ammende nel V secolo a.C. Mettendo in prospettiva i dati letterari con quelli giuridici, archeologici e storico-linguistici, il contributo intende mettere in discussione l'idea, introdotta da Theodor Mommsen nel 1860 e spesso seguita fino ad oggi, secondo cui tra il c. 450 e il 430 a.C. si sarebbe realizzato il completo superamento delle “primitive” forme di pagamento in bestiame a favore – a seguito di una breve fase di sovrapposizione – del solo uso del bronzo monetale. I sistemi di fonti discussi nel saggio mostrerebbero, innanzitutto, come le multe calcolate in capi di bestiame – che esistevano verosimilmente sin dall’età regia – avrebbero continuato ad essere comminate ben oltre il V secolo a.C. Inoltre, in età arcaica tali multe facevano parte di un quadro complesso, stratificato e in fieri in cui, per reati di natura e gravità differente erano previste forme di pagamento anch’esse differenziate, che vennero stabilite e ripensate sulla base delle diverse circostanze storiche e politico-istituzionali. In particolare, specialmente quando le multe previste erano di grande entità, il sistema giuridico romano arcaico dovette prevedere la possibilità di convertire la cifra, di norma stimata in assi, in alcuni beni (terra, case, schiavi), coerentemente con quanto avveniva, nella stessa fase storica, anche per il pagamento dei debiti privati dove, ad esempio, la cifra in assi dovuta al creditore poteva essere ripagata in lavoro (operae). La documentazione disponibile esclude, dunque, ogni forma di evoluzione lineare “dal bue al bronzo” in età arcaica ma suggerisce l’esistenza di un sistema complesso, integrato, ma instabile, di differenti forme di pagamento, in cui, peraltro, l’uso concreto del bronzo a peso appare obbligatorio solo in un numero piuttosto limitato di circostanze.
description: HISTORIKA Studi di storia greca e romana, V. 11 (2021)
Classification of Pulsar Glitch Amplitudes using Extreme Deconvolution
Creators: name: Arumugam, Swetha
name: Desai, Shantanu
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: We carry out a classification of the glitch amplitudes of radio pulsars using Extreme Deconvolution technique based on the Gaussian Mixture Model, where the observed uncertainties in the glitch amplitudes $Δν/ν$ are taken into account. Our dataset consists of 699 glitches from 238 pulsars. We then use information theory criteria such as AIC and BIC to determine the optimum number of glitch classes. We find that both AIC and BIC show that the pulsar glitch amplitudes can be optimally described using a bimodal distribution. The mean values of $Δν/ν$ for the two components are equal to $4.79 \times 10^{-9}$ and $1.28 \times 10^{-6}$, respectively with standard deviation given by 1.01 and 0.55 dex. We also applied this method to classify the pulsar inter-glitch time intervals, and we find that AIC prefers two components, whereas BIC prefers a single component. The unified data set and analyses codes used in this work have been made publicly available.
description: 8 pages, 5 figures. Accepted for publication in JHEAP
Da Roma alle Alpi. Competizione nobiliare, consenso popolare e strategia militare nella politica espansionistica romana in Cisalpina tra la fine del III e l’inizio del II secolo a.C.
Creators: name: Bellomo, Michele
Publisher: name: HISTORIKA Studi di storia greca e romana
Year: 2022

description: Le numerose tappe con cui Roma giunse a estendere la sua egemonia sull’area cisalpina in età tardo-repubblicana e alto-imperiale sono state diffusamente analizzate dalla critica moderna. Soprattutto negli ultimi anni, un marcato interesse per lo sviluppo delle comunità locali e per le diverse modalità con cui fu accolta e assimilata la penetrazione romana ha portato alla realizzazione di pregevoli studi che, analizzando il fenomeno da molteplici prospettive, sono stati in grado di superare trattazioni per lungo tempo troppo focalizzate sugli aspetti più squisitamente militari di quest’ampio processo. Il presente contributo si propone di fornire un'ulteriore chiave di lettura dell'intero fenomeno analizzando le dinamiche politiche che nel periodo immediatamente precedente (III e II secolo a.C.) crearono le premesse militari e ideologiche fondamentali per tale conquista. Muovendo dalla premessa che lo sviluppo della politica estera a Roma in età repubblicana rispondeva, più che a una generale "Grande Strategia", ai rapporti di potere che si venivano a stabilire anno dopo anno tra i tre principali elementi della cosiddetta costituzione romana – il senato, i magistrati e le assemblee popolari –, esso mira a calarsi nel cuore delle dinamiche politiche che caratterizzarono quei determinati momenti in cui da Roma fu presa la decisione di impegnare le forze militari in questo particolare settore strategico. Una tale indagine permetterà di cogliere in che modo e seguendo quali pulsioni la classe dirigente romana arrivò a mutare la propria prospettiva strategica nei confronti dell'area cisalpina, che da territorio esterno ed estremo arrivò, nell'arco di poco meno di un secolo, a essere pienamente inclusa - almeno sotto il piano ideologico - nel dominio romano.
description: HISTORIKA Studi di storia greca e romana, V. 11 (2021)
Compressive Sensing with Wigner $D$-functions on Subsets of the Sphere
Creators: name: Valdez, Marc Andrew
name: Yuffa, Alex J.
name: Wakin, Michael B.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Signal Processing (eess.SP)
subject: Information Theory (cs.IT)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: In this paper, we prove a compressive sensing guarantee for restricted measurement domains on the rotation group, $\mathrm{SO}(3)$. We do so by first defining Slepian functions on a measurement sub-domain $R$ of the rotation group $\mathrm{SO}(3)$. Then, we transform the inverse problem from the measurement basis, the bounded orthonormal system of band-limited Wigner $D$-functions on $\mathrm{SO}(3)$, to the Slepian functions in a way that limits increases to signal sparsity. Contrasting methods using Wigner $D$-functions that require measurements on all of $\mathrm{SO}(3)$, we show that the orthogonality structure of the Slepian functions only requires measurements on the sub-domain $R$, which is select-able. Due to the particulars of this approach and the inherent presence of Slepian functions with low concentrations on $R$, our approach gives the highest accuracy when the signal under study is well concentrated on $R$. We provide numerical examples of our method in comparison with other classical and compressive sensing approaches. In terms of reconstruction quality, we find that our method outperforms the other compressive sensing approaches we test and is at least as good as classical approaches but with a significant reduction in the number of measurements.
On groups of Hölder diffeomorphisms and their regularity
Creators: name: Nenning, David Nicolas
name: Rainer, Armin
Publisher: name: arXiv
Year: 2016
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Differential Geometry (math.DG)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 37C10, 58B10, 58B25, 58C07, 58D05

description: We study the set $\mathcal D^{n,β}(\mathbb R^d)$ of orientation preserving diffeomorphisms of $\mathbb R^d$ which differ from the identity by a Hölder $C^{n,β}_0$-mapping, where $n \in \mathbb N_{\ge 1}$ and $β\in (0,1]$. We show that $\mathcal D^{n,β}(\mathbb R^d)$ forms a group, but left translations in $\mathcal D^{n,β}(\mathbb R^d)$ are in general discontinuous. The groups $\mathcal D^{n,β-}(\mathbb R^d) := \bigcap_{α< β} \mathcal D^{n,α}(\mathbb R^d)$ (with its natural Fréchet topology) and $\mathcal D^{n,β+}(\mathbb R^d) := \bigcup_{α> β} \mathcal D^{n,α}(\mathbb R^d)$ (with its natural inductive locally convex topology) however are $C^{0,ω}$ Lie groups for any slowly vanishing modulus of continuity $ω$. In particular, $\mathcal D^{n,β-}(\mathbb R^d)$ is a topological group and a so-called half-Lie group (with smooth right translations). We prove that the Hölder spaces $C^{n,β}_0$ are ODE closed, in the sense that pointwise time-dependent $C^{n,β}_0$-vector fields $u$ have unique flows $Φ$ in $\mathcal D^{n,β}(\mathbb R^d)$. This includes, in particular, all Bochner integrable functions $u \in L^1([0,1],C^{n,β}_0(\mathbb R^d,\mathbb R^d))$. For the latter and $n\ge 2$, we show that the flow map $L^1([0,1],C^{n,β}_0(\mathbb R^d,\mathbb R^d)) \to C([0,1],\mathcal D^{n,α}(\mathbb R^d))$, $u \mapsto Φ$, is continuous (even $C^{0,β-α}$), for every $α< β$. As an application we prove that the corresponding Trouvé group $\mathcal G_{n,β}(\mathbb R^d)$ from image analysis coincides with the connected component of the identity of $\mathcal D^{n,β}(\mathbb R^d)$.
description: 33 pages; typos corrected, accepted for publication in Trans. Amer. Math. Soc
Noise induced swarming of active particles
Creators: name: Zheng, Chunming
name: Tönjes, Ralf
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We report on the effect of spatially correlated noise on the velocities of self propelled particles. Correlations in the random forces acting on self propelled particles can induce directed collective motion, i.e. swarming. Even with repulsive coupling in the velocity directions, which favors a disordered state, strong correlations in the fluctuations can align the velocities locally leading to a macroscopic, turbulent velocity field. On the other hand, while spatially correlated noise is aligning the velocities locally, the swarming transition to globally directed motion is inhibited when the correlation length of the noise is nonzero, but smaller than the system size. We analyze the swarming transition in $d$ dimensional space in a mean field model of globally coupled velocity vectors.
description: 8 pages, 2 figures (9 panels), to appear in APS Physical Review E
Reproducible Knowledge Graph workflows for embedding chemical entities and associated biology of diseases: A use case in Mpox
Creators: name: Karki, Reagon
name: Gadiya, Yojana
name: Zaliani, Andrea
name: Gribbon, Philip
Publisher: name: Zenodo
Year: 2023
Subjects: mpox, poster, knowledge graph, workflow, eoscfuture, bycovid

description: This poster is a summary of scientific work done in https://doi.org/10.1093/bioadv/vbad045. It was presented in a workshop titled "Infectious Diseases Beyond COVID-19", organized by Leopoldina Institute (https://www.leopoldina.org/en/events/event/event/3054/).
Galaxies at a Cosmic-Ray Eddington Limit
Creators: name: Heintz, Evan
name: Zweibel, Ellen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Cosmic rays have been shown to be extremely important in the dynamics of diffuse gas in galaxies, helping to maintain hydrostatic equilibrium, and serving as a regulating force in star formation. In this paper, we address the influence of cosmic rays on galaxies by re-examining the theory of a cosmic ray Eddington limit, first proposed by Socrates et al. (2008) and elaborated upon by Crocker et al. (2021a) and Huang & Davis (2022). A cosmic ray Eddington limit represents a maximum cosmic ray energy density above which the interstellar gas cannot be in hydrostatic equilibrium, resulting in a wind. In this paper, we continue to explore the idea of a cosmic ray Eddington limit by introducing a general framework that accounts for the circumgalactic environment and applying it to five galaxies that we believe to be a good representative sample of the star forming galaxy population, using different cosmic ray transport models to determine what gives each galaxy the best chance to reach this limit. We show that while an Eddington limit for cosmic rays does exist, for our five galaxies, the limit either falls at star formation rates that are much larger or gas densities that are much lower than each galaxy's measured values. This suggests that cosmic ray pressure is not the main factor limiting the luminosity of starburst galaxies.
description: 20 pages, 4 figures, 6 tables, accepted to ApJ
Interpreting the time variable RM observed in the core region of the TeV blazar Mrk 421
Creators: name: Lico, R.
name: Gómez, J. L.
name: Asada, K.
name: Fuentes, A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In this work we interpret and discuss the time variable rotation measure (RM) found, for the first time over a 1-yr period, in the core region of a blazar. These results are based on a one-year, multi-frequency (15, 24, and 43 GHz) Very Long Baseline Array (VLBA) monitoring of the TeV blazar Markarian 421 (Mrk 421). We investigate the Faraday screen properties and its location with respect to the jet emitting region. Given that the 43 GHz radio core flux density and the RM time evolution suggest a similar trend, we explore the possible connection between the RM and the accretion rate. Among the various scenarios that we explore, the jet sheath is the most promising candidate for being the main source of Faraday rotation. During the one-year observing period the RM trend shows two sign reversals, which may be qualitatively interpreted within the context of the magnetic tower models. We invoke the presence of two nested helical magnetic fields in the relativistic jet with opposite helicities, whose relative contribution produce the observed RM values. The inner helical field has the poloidal component ($B_{\rm p}$) oriented in the observer's direction and produces a positive RM, while the outer helical field, with $B_{\rm p}$ in the opposite direction, produces a negative RM. We assume that the external helical field dominates the contribution to the observed RM, while the internal helical field dominates when a jet perturbation arises during the second observing epoch. Being the intrinsic polarization angle parallel to the jet axis, a pitch angle of the helical magnetic field $ϕ\gtrsim 70^\circ$ is required. Additional scenarios are also considered to explain the observed RM sign reversals.
description: 6 pages, 2 figures. Published on MNRAS
Weakening of the diamagnetic shielding in FeSe$_{1-x}$S$_x$ at high pressures
Creators: name: Yip, K. Y.
name: Chan, Y. C.
name: Niu, Q.
name: Matsuura, K.
name: Mizukami, Y.
name: Kasahara, S.
name: Matsuda, Y.
name: Shibauchi, T.
name: Goh, Swee K.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The superconducting transition of FeSe$_{1-x}$S$_x$ with three distinct sulphur concentrations $x$ was studied under hydrostatic pressure up to $\sim$70 kbar via bulk AC susceptibility. The pressure dependence of the superconducting transition temperature ($T_c$) features a small dome-shaped variation at low pressures for $x=0.04$ and $x=0.12$, followed by a more substantial $T_c$ enhancement to a value of around 30 K at moderate pressures. In $x=0.21$, a similar overall pressure dependence of $T_c$ is observed, except that the small dome at low pressures is flattened. For all three concentrations, a significant weakening of the diamagnetic shielding is observed beyond the pressure around which the maximum $T_c$ of 30 K is reached near the verge of pressure-induced magnetic phase. This observation points to a strong competition between the magnetic and high-$T_c$ superconducting states at high pressure in this system.
description: 5 pages, 4 figures + Supplemental Material (2 pages, 3 figures). Accepted for publication in Phys. Rev. B (Rapid Comm.)
On the Klein-Gordon scalar field oscillators in a spacetime with spiral-like dislocations in external magnetic fields
Creators: name: Mustafa, O.
name: Guvendi, A.
Publisher: name: arXiv
Year: 2025
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the effects of two types of spiral dislocation (the distortion of the radial line, labeled as spiral dislocation I, and the distortion of a circle, labeled as spiral dislocation II) on the relativistic dynamics of the Klein-Gordon (KG) oscillator fields, both in the presence and absence of external magnetic fields. In this context, our investigations show that while spiral dislocation I affects the energies of the KG oscillators (with or without the magnetic field), spiral dislocation II has, interestingly, no effect on the KG oscillator's energies unless a magnetic field is applied. However, for both types of spiral dislocations, we observe that the corresponding wave functions incorporate the effects of the dislocation parameter. Our findings are based on the exact solvability and conditional exact solvability (associated with the biconfluent Heun polynomials) of the KG oscillators (with or without the magnetic field, respectively) for spiral dislocation I, and the exact solvability of the KG oscillators (with or without the magnetic field) for spiral dislocation II. The exact solvability of the latter suggests that the oscillator's frequency is solely determined by the magnetic field strength.
description: 11 pages, 3 figures, EJPC to appear
Exploring Predictive States via Cantor Embeddings and Wasserstein Distance
Creators: name: Loomis, Samuel P.
name: Crutchfield, James P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Machine Learning (cs.LG)
subject: Dynamical Systems (math.DS)
subject: Machine Learning (stat.ML)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Predictive states for stochastic processes are a nonparametric and interpretable construct with relevance across a multitude of modeling paradigms. Recent progress on the self-supervised reconstruction of predictive states from time-series data focused on the use of reproducing kernel Hilbert spaces. Here, we examine how Wasserstein distances may be used to detect predictive equivalences in symbolic data. We compute Wasserstein distances between distributions over sequences ("predictions"), using a finite-dimensional embedding of sequences based on the Cantor for the underlying geometry. We show that exploratory data analysis using the resulting geometry via hierarchical clustering and dimension reduction provides insight into the temporal structure of processes ranging from the relatively simple (e.g., finite-state hidden Markov models) to the very complex (e.g., infinite-state indexed grammars).
description: 9 pages, 4 figures; http://csc.ucdavis.edu/~cmg/compmech/pubs/PredStateCantorWass.htm
Constraints on leptophilic dark matter from the AMS-02 experiment
Creators: name: Cavasonza, Leila Ali
name: Gast, Henning
name: Krämer, Michael
name: Pellen, Mathieu
name: Schael, Stefan
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The annihilation of dark matter particles in the galactic halo of the Milky Way may lead to cosmic ray signatures that can be probed by the AMS-02 experiment, which has measured the composition and fluxes of charged cosmic rays with unprecedented precision. Given the absence of characteristic spectral features in the electron and positron fluxes measured by AMS-02, we derive upper limits on the dark matter annihilation cross section for leptophilic dark matter models. Our limits are based on a new background model that describes all recent measurements of the energy spectra of cosmic ray positrons and electrons. For thermal dark matter relics, we can exclude dark matter masses below about 100 GeV. We include the radiation of electroweak gauge bosons in the dark matter annihilation process and compute the antiproton signal that can be expected within leptophilic dark matter models.
description: 7 pages, 3 figures, 1 table. Matches the published version apart from typo corrected in Eq.2
Topological Antiferromagnetic Semimetal for Spintronics: A Case Study of a Layered Square Net System EuZnSb$_2$
Creators: name: Aryal, Niraj
name: Li, Qiang
name: Tsvelik, A. M.
name: Yin, Weiguo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We use the first principles and effective Hamiltonian methods to study the electronic structure and magnetic properties of a recently synthesized layered antiferromagnetic square net topological semimetal EuZnSb$_2$ [1]. The main message of the paper is that effects of small changes in the band structure produced by the magnetic ordering and changes in the orientation of the \Neel vector are amplified in such transport properties as the spin Hall conductivity. We predict that the effects of the broken symmetry introduced by the ordering of the \Neel vector, being very weak in the bulk, are pronounced in the surface electronic dispersion, suggesting that surface probes may be more suited to measure them. The coexistence of the magnetism with many other competing phases make this material interesting and possibly useful for quantum spintronics applications.
description: 16 pages
Eruzioni vulcaniche e svolte storiche. A proposito dei recenti sviluppi negli studi paleoclimatici e delle loro implicazioni
Creators: name: Marcone, Arnaldo
Publisher: name: HISTORIKA Studi di storia greca e romana
Year: 2022

description: L'assassinio di Giulio Cesare nel 44 a.C. scatenò una lotta per il potere che alla fine provocò il tracollo della Repubblica Romana e, quindi, del Regno Tolemaico, aprendo la strada alla nascita dell'Impero Romano. Simulazioni climatiche e documenti scritti indicano che questa lotta è avvenuta durante un periodo di tempo insolitamente inclemente, con carestie e malattie nella regione mediterranea. Taluni storici avevano già in passato ipotizzato che una grande eruzione vulcanica di origine sconosciuta ne fosse la causa più probabile. Una delle più grandi eruzioni vulcaniche degli ultimi 2.500 si è effettivamente verificata all'inizio del 43 a.C. Alcune speculazioni sono quindi ammissibili.
description: HISTORIKA Studi di storia greca e romana, V. 11 (2021)
NUT-like and near-horizon limits of Kerr-NUT-(A)dS spacetimes
Creators: name: Kolar, Ivan
name: Krtous, Pavel
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study a class of limits of the higher-dimensional Kerr-NUT-(A)dS spacetimes where particular roots of metric functions degenerate. Namely, we obtain the Taub-NUT-(A)dS and the extreme near-horizon geometries as two examples of our limiting procedure. The symmetries of the resulting spacetimes are enhanced which is manifested by the presence of supplementary Killing vectors and decomposition of Killing tensors into Killing vectors.
description: 22 pages, 8 figures
A simple quantum model linked to a theory of decisions
Creators: name: Helland, Inge S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: This article may be seen as a summary and a final discussion of the work that the author has done in recent years on the foundation of quantum theory. It is shown that quantum mechanics as a model follows under certain specific conditions from a quite different, much simpler model. This model is connected to the mind of an observer, or to the joint minds of a group of communicating observers. The model is based upon conceptual variables, and an important aspect is that an observer (a group of observers) must decide on which variable to measure. The model is then linked more generally to a theory of decisions. The results are discussed from several angles. In particular, macroscopic consequences are treated briefly.
description: 17 pages. arXiv admin note: text overlap with arXiv:2108.12168
Vacuum polarization throughout general subtracted black hole spacetimes
Creators: name: Satz, Alejandro
name: Cvetic, Mirjam
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We compute the vacuum polarization of a massless minimally co pled scalar field in a background given by a black hole with subtracted geometry. Extending previous results for the horizon of rotating black holes with no charge, we obtain an analytical expression for the vacuum polarization that is valid throughout the spacetime and for arbitrary rotation and charge parameters. The vacuum polarization diverges at the inner horizon and the quantum state cannot be extended to the inside of it.
description: 22 pages, 4 figures. Minor changes, one reference added. Final published version
An Approach to Quantum 2D Gravity
Creators: name: Belokurov, Vladimir V.
name: Shavgulidze, Evgeniy T.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider a model of 2D gravity with the action quadratic in curvature and represent path integrals as integrals over the SL(2, R) invariant Gaussian functional measure. We reduce these path integrals to the products of Wiener path integrals and calculate the correlation function of the metric in the first perturbative order.
description: 10 pages
Un servo del municipio e i Publicii in iscrizioni inedite di Taranto
Creators: name: Gallo, Annarosa
Publisher: name: HISTORIKA Studi di storia greca e romana
Year: 2022

description: Il contributo analizza sette iscrizioni inedite provenienti dal municipium di Taranto, una delle quali appartenente a un servo pubblico. Le altre iscrizioni riguardano l’attestazione del gentilizio Publicius.
description: HISTORIKA Studi di storia greca e romana, V. 11 (2021)
Fitting covariance matrix models to simulations
Creators: name: Fumagalli, Alessandra
name: Biagetti, Matteo
name: Saro, Alexandro
name: Sefusatti, Emiliano
name: Slosar, Anže
name: Monaco, Pierluigi
name: Veropalumbo, Alfonso
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: 85A40

description: Data analysis in cosmology requires reliable covariance matrices. Covariance matrices derived from numerical simulations often require a very large number of realizations to be accurate. When a theoretical model for the covariance matrix exists, the parameters of the model can often be fit with many fewer simulations. We write a likelihood-based method for performing such a fit. We demonstrate how a model covariance matrix can be tested by examining the appropriate $χ^2$ distributions from simulations. We show that if model covariance has amplitude freedom, the expectation value of second moment of $χ^2$ distribution with a wrong covariance matrix will always be larger than one using the true covariance matrix. By combining these steps together, we provide a way of producing reliable covariances without ever requiring running a large number of simulations. We demonstrate our method on two examples. First, we measure the two-point correlation function of halos from a large set of $10000$ mock halo catalogs. We build a model covariance with $2$ free parameters, which we fit using our procedure. The resulting best-fit model covariance obtained from just $100$ simulation realizations proves to be as reliable as the numerical covariance matrix built from the full $10000$ set. We also test our method on a setup where the covariance matrix is large by measuring the halo bispectrum for thousands of triangles for the same set of mocks. We build a block diagonal model covariance with $2$ free parameters as an improvement over the diagonal Gaussian covariance. Our model covariance passes the $χ^2$ test only partially in this case, signaling that the model is insufficient even using free parameters, but significantly improves over the Gaussian one.
description: Accepted for publication in JCAP. 24 pages, 8 figures
Observing Power-Law Dynamics of Position-Velocity Correlation in Anomalous Diffusion
Creators: name: Afek, Gadi
name: Coslovsky, Jonathan
name: Courvoisier, Arnaud
name: Livneh, Oz
name: Davidson, Nir
Publisher: name: arXiv
Year: 2017
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: In this letter we present a measurement of the phase-space density distribution (PSDD) of ultra-cold \Rb atoms performing 1D anomalous diffusion. The PSDD is imaged using a direct tomographic method based on Raman velocity selection. It reveals that the position-velocity correlation function $C_{xv}(t)$ builds up on a timescale related to the initial conditions of the ensemble and then decays asymptotically as a power-law. We show that the decay follows a simple scaling theory involving the power-law asymptotic dynamics of position and velocity. The generality of this scaling theory is confirmed using Monte-Carlo simulations of two distinct models of anomalous diffusion.
description: 5 pages, 4 figures in main text. 13 pages, 8 figures in supplementary Accepted for publication in PRL
Quantum dynamics of a $4π$-kink in Josephson junctions parallel arrays with large kinetic inductances
Creators: name: Seidov, S. S.
name: Fistul, M. V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We present a theoretical study of the quantum dynamics of \textit{two} magnetic fluxons (MFs) trapped in Josephson junction parallel arrays (JJPAs) with large kinetic inductances. The Josephson phase distribution of two trapped MFs satisfies a topological constraint, i.e., a total variation of Josephson phases along a JJPA is $4π$. In such JJPAs the characteristic length of Josephson phase distribution ("the size" of MF) is drastically reduced to be less than a single cell size. Two extreme dynamic patterns will be distinguished: two weakly interacting MFs and two merged MFs, i.e., a $4π$-kink. Taking into account the repulsive interaction between two MFs located in the same or adjacent cells we obtain the energy band spectrum $E_{4π}(p)$ for a quantum $4π$-kink. The coherent quantum dynamics of a $4π$-kink demonstrates the quantum beats with the frequency and amplitude strongly deviating from ones observed for two independent MFs. In the presence of applied dc and ac bias current of frequency $f$ a weakly incoherent quantum dynamics of a $4π$-kink results in the Bloch oscillations and the seminal current steps with values $I^{(n)}_{4π}=enf$ which are two times less than ones for two independent MFs.
La fatica degli animali: bestie da soma nella Cappadocia ellenistico-romana
Creators: name: Cassia, Margherita
Publisher: name: HISTORIKA Studi di storia greca e romana
Year: 2022

description: La fama della Cappadocia come regione d’origine di cavalli da corsa di razza pregiata – destinati a scopi militari, al servizio postale imperiale e ai ludi circenses – è ben conosciuta; anzi, secondo un’ipotesi suggestiva, la regione avrebbe tratto il suo nome dai due termini ittiti hvaçpa-dakhin, “terra dei bei cavalli”. Il presente studio affronta un aspetto meno noto, ossia la presenza nella regione di bestie da soma, documentate dall’età ellenistica alla Tarda Antichità e adoperate nei trasporti di persone e cose su lunghe, medie e brevi distanze, ma adibite anche ad alleviare la fatica dell’uomo durante le attività agricole, e destinate alla produzione di latte, carne e tessuti, al trasporto di passeggeri e di ammalati, al servizio di posta imperiale.
description: HISTORIKA Studi di storia greca e romana, V. 11 (2021)
Einstein relation and hydrodynamics of nonequilibrium mass transport processes
Creators: name: Das, Arghya
name: Kundu, Anupam
name: Pradhan, Punyabrata
Publisher: name: arXiv
Year: 2017
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We obtain hydrodynamic descriptions of a broad class of conserved-mass transport processes on a ring. These processes are governed by chipping, diffusion and coalescence of masses, where microscopic probability weights in their nonequilibrium steady states, having nontrivial correlations, are not known. In these processes, we analytically calculate two transport coefficients, the bulk-diffusion coefficient and the conductivity. We, remarkably, find that the two transport coefficients obey an equilibriumlike Einstein relation, although the microscopic dynamics does not satisfy detailed balance condition. Using macroscopic fluctuation theory, we also show that probability of density fluctuations obtained from the hydrodynamic description is in complete agreement with the same derived earlier in [Phys. Rev. E 93, 062135 (2016)] using an additivity property.
description: 11 pages
Role of magnetic fields in fueling Seyfert nuclei
Creators: name: Hu, Yue
name: Lazarian, Alex
name: Beck, Rainer
name: Xu, Siyao
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Molecular gas is believed to be the fuel for star formation and nuclear activity in Seyfert galaxies. To explore the role of magnetic fields in funneling molecular gas into the nuclear region, measurements of the magnetic fields embedded in molecular gas are needed. By applying the new velocity gradient technique (VGT) to ALMA and PAWS's CO isotopolog data, we obtain the first detection of CO-associated magnetic fields in several nearby Seyfert galaxies and their unprecedented high-resolution magnetic field maps. The VGT-measured magnetic fields in molecular gas globally agree with those inferred from existing HAWC+ dust polarization and VLA synchrotron polarization. An overall good alignment between the magnetic fields traced by VGT-CO and by synchrotron polarization may support the correlation between star formation and cosmic ray generation. We find that the magnetic fields traced by VGT-CO have a significant radial component in the central regions of most Seyferts in our sample, where efficient molecular gas inflows or outflows may happen. In particular, we find local misalignment between the magnetic fields traced by CO and dust polarization within the nuclear ring of NGC 1097, and the former aligns with the central bar's orientation. This misalignment reveals different magnetic field configurations in different gas phases and may provide an observational diagnostic for the ongoing multi-phase fueling of Seyfert activity.
description: 24 pages, 14 figures
Jets in radio galaxies and quasars: an observational perspective
Creators: name: Saikia, D. J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: This article gives a brief historical introduction and reviews our current understanding of jets in radio galaxies and quasars from an observational perspective, with an emphasis on observations at radio wavelengths. Recent results on the Fanaroff-Riley classification scheme, and the nature of radio structures and jets in the FR classes as well as in high-excitation and low-excitation radio galaxies are summarized. The collimation and propagation of jets from nuclear sub-pc to hundreds of kpc scales from both observatinoal and theoretical work have been discussed. The jets exhibit evidence of interaction with a clumpy interstellar medium, especially in young radio sources, and could trigger both star formation as well as suppress star formation depending on the physical conditions. Observational evidence for such interactions and jet feedback which have profound implications in our understanding of galaxy evolution have been presented. Recurrent jet activity which has been seen over a wide range of projected linear size and time scales has been discussed. This review article concludes with a brief discussion of unresolved questions on jets which new telescopes should help address.
description: 30 pages, 14 figures, accepted for publication in the Journal of Astrophysics and Astronomy, Proceedings of the ARIES, Nainital, India conference on jets titled Astrophysical jets and observational facilities: National perspective; guest editors Shashi Pandey, Alok Gupta and Sachindra Naik
La memoria del tiranno: Anassilao di Reggio tra protagonismo personale e oblio letterario
Creators: name: Bianchi, Edoardo
Publisher: name: HISTORIKA Studi di storia greca e romana
Year: 2022

description: Questo articolo si propone un duplice obiettivo. Innanzitutto, vuole analizzare come Anassilao sfruttò i contesti performativi e i canali comunicativi che, nei primi decenni del V secolo a.C., erano a disposizione dei tiranni di Magna Grecia e Sicilia desiderosi di garantire fama alle loro imprese, nonché legittimazione al proprio ruolo e operato politico. Secondariamente, intende ricostruire le tappe che portarono alla sostanziale cancellazione della memoria di Anassilao sul piano storiografico. A questo proposito, una responsabilità decisiva sembra da attribuire a Eforo, il quale, nelle sue Storie, mise in secondo piano quel ruolo antagonistico rispetto ai Dinomenidi che, a tutti gli effetti, Anassilao aveva svolto in Sicilia fino alla battaglia di Himera.
description: HISTORIKA Studi di storia greca e romana, V. 11 (2021)
Effective non-linear dynamics of binary condensates and open problems
Creators: name: Olgiati, Alessandro
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 46N50, 35Q40, 35Q55, 81Q05, 81V70, 82C10

description: We report on a recent result concerning the effective dynamics for a mixture of Bose-Einstein condensates, a class of systems much studied in physics and receiving a large amount of attention in the recent literature in mathematical physics; for such models, the effective dynamics is described by a coupled system of non-linear Schödinger equations. After reviewing and commenting our proof in the mean field regime from a previous paper, we collect the main details needed to obtain the rigorous derivation of the effective dynamics in the Gross-Pitaevskii scaling limit.
description: Corrected typos, updated references
Increasing the impact of your research by using rich, integrated and open-access communications
Creators: name: Vittorio, Iacovella
Publisher: name: Zenodo
Year: 2020
Subjects: altmetrics
open access
openscience
twitter
tweetdeck
nuzzel
iris

description: Communication of research outputs evolves, following both technological advancements and scientific demands. Once formal and static physical objects, research publications are currently combinations of text, code, data and several other digital products. Here I first introduce alternative ways to track the impact of your products ("alt-metrics") in an open-access environment; then I show how to collect and integrate online different pieces of relevant information using twitter and twitter-related tools.
Decimations for One- and Two-dimensional Ising and Rotator Models II: Continuous versus Discrete Symmetries
Creators: name: D'Achille, Matteo
name: Ny, Arnaud Le
name: van Enter, Aernout C. D.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mathematical Physics (math-ph)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 60K35 (Primary), 82B20 (Secondary)

description: We show how decimated Gibbs measures which have an unbroken continuous symmetry due to the Mermin-Wagner theorem, although their discrete equivalents have a phase transition, still can become non-Gibbsian. The mechanism rests on the occurrence of a spin-flop transition with a broken discrete symmetry, once the model is constrained by the decimated spins in a suitably chosen "bad" configuration.
description: 16 pages, 1 figure (updated)
Metamaterial analog of a black hole shadow: An exact ray-tracing simulation based on the spacetime index of refraction
Creators: name: Nouri-Zonoz, M.
name: Parvizi, A.
name: Forghani, H.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: In this letter first we show that the equation of null geodesics in spherically symmetric spacetimes in isotropic coordinates is identical to the equation of light ray trajectories in isotropic media in flat spacetime. Based on this analogy we introduce an exact simulation of the light ray trajectories both in these spacetimes and in their metamaterial analogs in terms of the spacetime index of refraction. As unstable light trajectories, the photon spheres form in these metamaterial analogs at {\it exactly} the same radial distances as expected from the corresponding black hole geometries. Using the same ray-tracing simulation we find the analog of a simple black hole shadow formed by the metamaterial analog of a Schwarzschild black hole, eclipsing a line of light sources near its analog horizon.
description: 14 pages, 7 figures, typos corrected and the resolution of last figure is enhanced
The ASAS-SN Bright Supernova Catalog -- III. 2016
Creators: name: Holoien, T. W. -S.
name: Brown, J. S.
name: Stanek, K. Z.
name: Kochanek, C. S.
name: Shappee, B. J.
name: Prieto, J. L.
name: Dong, Subo
name: Brimacombe, J.
name: Bishop, D. W.
name: Bose, S.
name: Beacom, J. F.
name: Bersier, D.
name: Chen, Ping
name: Chomiuk, L.
name: Falco, E.
name: Godoy-Rivera, D.
name: Morrell, N.
name: Pojmanski, G.
name: Shields, J. V.
name: Strader, J.
name: Stritzinger, M. D.
name: Thompson, Todd A.
name: Woźniak, P. R.
name: Bock, G.
name: Cacella, P.
name: Conseil, E.
name: Cruz, I.
name: Fernandez, J. M.
name: Kiyota, S.
name: Koff, R. A.
name: Krannich, G.
name: Marples, P.
name: Masi, G.
name: Monard, L. A. G.
name: Nicholls, B.
name: Nicolas, J.
name: Post, R. S.
name: Stone, G.
name: Wiethoff, W. S.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: This catalog summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright ($m_{peak}\leq17$), spectroscopically confirmed supernovae discovered in 2016. We then gather the near-IR through UV magnitudes of all host galaxies and the offsets of the supernovae from the centers of their hosts from public databases. We illustrate the results using a sample that now totals 668 supernovae discovered since 2014 May 1, including the supernovae from our previous catalogs, with type distributions closely matching those of the ideal magnitude limited sample from Li et al. (2011). This is the third of a series of yearly papers on bright supernovae and their hosts from the ASAS-SN team.
description: 15 pages, 6 figures, 4 tables. Manuscript updated to reflect changes made in the published version. Tables containing the catalog data presented in this submission are included in machine-readable format as ancillary files. For a brief video explaining this paper, see https://youtu.be/LGm3NVO9yz0
Cittadinanza e archivi nel Mediterraneo Antico: qualche postilla esegetica
Creators: name: Saba, Sara
Publisher: name: HISTORIKA Studi di storia greca e romana
Year: 2022

description: Il contributo discute alcune testimonianze epigrafiche su pratiche archivistiche riferibili alla registrazione di neocittadini in particolari situazioni, quali costituzioni di nuove poleis o definizione di trattati interstatali con potenziale impatto sul corpo civico. Oltre ad osservare, come è stato già fatto in precedenza in dottrina, quanto le comunità greche avessero archivi funzionali e funzionanti, questo articolo cerca di offrire da un lato un contributo esegetico alla lista Tit.Cal. 88, dall’altro prova a riflettere su come momenti di ‘rottura istituzionale’, come ad esempio atti di sympoliteia o accordi di isopoliteia, potessero influenzare da un lato le registrazioni d’archivio e, dall’altro, su quale fosse il loro uso.
description: HISTORIKA Studi di storia greca e romana, V. 11 (2021)
Membrane flutter in three-dimensional inviscid flow
Creators: name: Mavroyiakoumou, Christiana
name: Alben, Silas
Publisher: name: arXiv
Year: 2022
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We develop a model and numerical method to study the large-amplitude flutter of rectangular membranes (of zero bending rigidity) that shed a trailing vortex-sheet wake in a three-dimensional (3D) inviscid fluid flow. We apply small initial perturbations and track their decay or growth to large-amplitude steady state motions. For 12 combinations of boundary conditions at the membrane edges we compute the stability thresholds and the subsequent large-amplitude dynamics across the three-parameter space of membrane mass density, pretension, and stretching rigidity. With free side edges we find good agreement with previous 2D results that used different discretization methods. We find that the 3D dynamics in the 12 cases naturally form four groups based on the conditions at the leading and trailing edges. The deflection amplitudes and oscillation frequencies have scalings similar to those in the 2D case. The conditions at the side edges, though generally less important, may have small or large qualitative effects on the membrane dynamics -- e.g. steady versus unsteady, periodic versus chaotic, or the variety of spanwise curvature distributions -- depending on the group and the physical parameter values.
description: 40 pages, 16 figures