cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
GCM Simulations of Unstable Climates in the Habitable Zone
Creators: name: Paradise, Adiv
name: Menou, Kristen
Publisher: name: arXiv
Year: 2017
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: It has recently been proposed that Earth-like planets in the outer regions of the habitable zone experience unstable climates, repeatedly cycling between glaciated and deglaciated climatic states (Menou 2015). While this result has been confirmed and also extended to explain early Mars climate records (Haqq-Misra et al. 2016; Batalha et al. 2016), all existing work relies on highly idealized low-dimensional climate models. Here, we confirm that the phenomenology of climate cycles remains in 3D Earth climate models with considerably more degrees of freedom. To circumvent the computational barrier of integrating climate on Gyr timescales, we design a hybrid 0D-3D integrator which uses a general circulation model (GCM) as a short relaxation step along a long evolutionary climate sequence. We find that GCM climate cycles are qualitatively consistent with reported low-dimensional results. This establishes on a firmer ground the notion that outer habitable zone planets may be preferentially found in transiently glaciated states.
description: 20 pages, 8 figures, accepted to ApJ (in press). Minor corrections in abstract
NLO Perturbativity Bounds on Quartic Couplings in Renormalizable Theories with $ϕ^4$-like Scalar Sectors
Creators: name: Murphy, Christopher W.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The apparent breakdown of unitarity in low order perturbation theory is often is used to place bounds on the parameters of a theory. In this work we give an algorithm for approximately computing the next-to-leading order (NLO) perturbativity bounds on the quartic couplings of a renormalizable theory whose scalar sector is $ϕ^4$-like. By this we mean theories where either there are no cubic scalar interactions, or the cubic couplings are related to the quartic couplings through spontaneous symmetry breaking. The quantity that tests where perturbation theory breaks down itself can be written as a perturbative series, and having the NLO terms allows one to test how well the series converges. We also present a simple example to illustrate the effect of considering these bounds at different orders in perturbation theory. For example, there is a noticeable difference in the viable parameter when the square of the NLO piece is included versus when it is not.
description: v2: 11 pages, 2 figures, version to appear in PRD
Planar Hall Effect in Quasi-Two-Dimensional Materials
Creators: name: Ghorai, Koushik
name: Das, Sunit
name: Varshney, Harsh
name: Agarwal, Amit
Publisher: name: arXiv
Year: 2024
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The planar Hall effect in 3D systems is an effective probe for their Berry curvature, topology, and electronic properties. However, the Berry curvature-induced conventional planar Hall effect is forbidden in 2D systems as the out-of-plane Berry curvature cannot couple to the band velocity of the electrons moving in the 2D plane. Here, we demonstrate a unique 2D planar Hall effect (2DPHE) originating from the hidden planar components of the Berry curvature and orbital magnetic moment in quasi-2D materials. We identify all planar band geometric contributions to 2DPHE and classify their crystalline symmetry restrictions. Using gated bilayer graphene as an example, we show that in addition to capturing the hidden band geometric effects, 2DPHE is also sensitive to the Lifshitz transitions. Our work motivates further exploration of hidden planar band geometry-induced 2DPHE and related transport phenomena for innovative applications.
description: Minor changes, Supplementary file included
The sequence of open and closed prefixes of a Sturmian word
Creators: name: De Luca, Alessandro
name: Fici, Gabriele
name: Zamboni, Luca Q.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Discrete Mathematics (cs.DM)
subject: Formal Languages and Automata Theory (cs.FL)
subject: Combinatorics (math.CO)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: 68R15

description: A finite word is closed if it contains a factor that occurs both as a prefix and as a suffix but does not have internal occurrences, otherwise it is open. We are interested in the {\it oc-sequence} of a word, which is the binary sequence whose $n$-th element is $0$ if the prefix of length $n$ of the word is open, or $1$ if it is closed. We exhibit results showing that this sequence is deeply related to the combinatorial and periodic structure of a word. In the case of Sturmian words, we show that these are uniquely determined (up to renaming letters) by their oc-sequence. Moreover, we prove that the class of finite Sturmian words is a maximal element with this property in the class of binary factorial languages. We then discuss several aspects of Sturmian words that can be expressed through this sequence. Finally, we provide a linear-time algorithm that computes the oc-sequence of a finite word, and a linear-time algorithm that reconstructs a finite Sturmian word from its oc-sequence.
description: Published in Advances in Applied Mathematics. Journal version of arXiv:1306.2254
Geodesic description of Heavy-Light Virasoro blocks
Creators: name: Belavin, V. A.
name: Geiko, R. V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We continue to investigate the dual description of the Virasoro conformal blocks arising in the framework of the classical limit of the AdS$_3$/CFT$_2$ correspondence. To give such an interpretation in previous studies, certain restrictions were necessary. Our goal here is to consider more general situation available through the worldline approximation to the dual AdS gravity. Namely, we are interested in computing the spherical conformal blocks without the previously imposed restrictions on the conformal dimensions of the internal channels. The duality is realised as an equality of the so-called heavy-light limit of the n-point conformal block and the action of n-2 particles propagating in some AdS-like background with either a conical singularity or a BTZ black hole. We describe a procedure that allows relaxing the constraint on the intermediate channels. To obtain an explicit expression for the conformal block on the CFT side, we use a recently proposed recursion procedure and find full agreement between the results of the boundary and bulk computations.
description: 13 pages, v3: refs added, typos removed
Stochastic Kinetic Theory for Collective Behavior of Hydrodynamically Interacting Active Particles
Creators: name: Qian, Yuzhou
name: Kramer, Peter R.
name: Underhill, Patrick T.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Self-propelled particles with hydrodynamic interactions (microswimmers) have previously been shown to produce long-range ordering phenomena. Many theoretical explanations for these collective phenomena are connected to instabilities in the hydrodynamic or kinetic equations. By incorporating stochastic fluxes into the mean field kinetic equation, we quantify the dynamics of a suspension of microswimmers in the parameter regime where the deterministic equation is stable. We can thereby compute nontrivial collective phenomena concerning spatial correlations of orientation and stress as well as the enhanced diffusion of tracer particles. Our analysis here focuses primarily on two-dimensional systems, though we also show how superdiffusion of tracers in three dimensions can occur by our framework.
Relativistic corrections to the form factors of $B_c$ into $S$-wave Charmonium
Creators: name: Zhu, Ruilin
name: Ma, Yan
name: Han, Xin-Ling
name: Xiao, Zhen-Jun
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We investigate the form factors of $B_c$ meson into $S$-wave charmonium within the nonrelativistic QCD effective theory and obtain the next-to-leading order relativistic corrections to the form factors, where both the $B_c$ meson and the charmonium are treated as the nonrelativistic bound states. Treating the charm quark as a light quark in the limit \ $m_c/m_b\to 0$, some form factors are identical at the maximum recoil point, which are consistent with the predictions in the heavy-quark effective theory and the large-energy effective theory. Considering that the branching ratios of $B^+_c \to J/ψD_s^+$ and $B^+_c \to J/ψD_s^{*+}$ have been measured by the LHCb and ATLAS Collaborations recently, we employ the form factors of $B_c$ meson into $S$-wave charmonium at the next-to-leading order accuracy to these two decay channels and obtain more precise predictions of their decay rates. Numerical results indicate that the factorizable diagrams dominate the contribution in these two channels, while the colour-suppressed and the annihilation diagrams contribute less than 10 percent. Our results are consistent with the LHCb and ATLAS data.
description: 10 pages, 2 figures and 2 tables. The typos are corrected and more discussions are added
Lophius budegassa Spinola 1807
Creators: name: Béarez, Philippe
name: Pruvost, Patrice
name: Feunteun, Eric
name: Iglésias, Samuel P.
name: Francour, Patrice
name: Causse, Romain
name: De Mazieres, Jeanne
name: Tercerie, Sandrine
name: Bailly, Nicolas
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Elasmobranchii
Lophiiformes
Lophiidae
Lophius
Lophius budegassa

description: Lophius budegassa Spinola, 1807 – Blackbellied angler –
Baudroie rousse
 Lophius piscatorius Linnaeus, 1758 – Angler – Baudroie commune
 Family Chaunacidae
 Chaunax pictus Lowe, 1846 – Pink frogmouth – Baudroie rose
 Family Oneirodidae
 Lophodolos acanthognathus Regan, 1925 – Whalehead dreamer – Rêveur à front haut
 Oneirodes carlsbergi (Regan & Trewavas, 1932) – Longtail dreamer – Rêveur à grande queue
 Oneirodes eschrichtii Lütken, 1871 – Cosmopolitan dreamer – Rêveur cosmopolite
 Family Ceratiidae
 Ceratias holboelli Krøyer, 1845 – Kroyer’s deep-sea angler fish – Noah
description: Published as part of Béarez, Philippe, Pruvost, Patrice, Feunteun, Eric, Iglésias, Samuel P., Francour, Patrice, Causse, Romain, De Mazieres, Jeanne, Tercerie, Sandrine & Bailly, Nicolas, 2017, Checklist of the marine fishes from metropolitan France, pp. 351-371 in Cybium 41 (4) on page 362, DOI: 10.26028/cybium/2017-414-006, http://zenodo.org/record/13479447
title: The Schwinger model in the canonical formulation
Creators: name: Bühlmann, Patrick
Publisher: name: Universität Bern
Year: 2022
Subjects: subject: 530 Physics

description: We investigate the Schwinger model in the canonical formulation with fixed fermion numbers. For this, Wilson fermions and a formalism which describes the determinant of the Dirac operator in terms of dimensionally reduced canonical determinants are used. These canonical determinants are built from sums over principal minors of canonical transfer matrices.

We consider the 1-flavour Schwinger model in a regime where the sign problem is absent and investigate several structural properties of the canonical determinants and their transfer matrices.

Next, we discuss the 2-flavour Schwinger model in the canonical formulation. The transfer matrices allow the direct examination of arbitrary multi-particle (meson) sectors and the determination of the corresponding ground state energies. We determine the ground state energies and utilize them to perform some basic scattering theory and investigate finite volume effects in the meson mass. From the 2-meson energies the scattering phase shifts as a function of the volume were determined. Using a low-energy scattering theory, we describe the scattering process in terms of a few physical parameters. We use the scattering phase shifts to solve 3-particle quantization conditions which allow us to make predictions for the 3-meson energies at finite volume. These predictions are compared to direct measurements of the 3-meson energies.
Strong dynamics in a classically scale invariant extension of the Standard Model with flatland
Creators: name: Haba, Naoyuki
name: Yamada, Toshifumi
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We investigate the scenario where the Standard Model is extended with classical scale invariance, which is broken by chiral symmetry breaking and confinement in a new strongly-coupled gauge theory that resembles QCD. The Standard Model Higgs field emerges as a result of the mixing of a scalar meson in the new strong dynamics and a massless elementary scalar field. The mass and scalar decay constant of that scalar meson, which are generated dynamically in the new gauge theory, give rise to the Higgs field mass term, automatically possessing the correct negative sign by the bosonic seesaw mechanism. Using analogy with QCD, we evaluate the dynamical scale of the new gauge theory and further make quantitative predictions for light pseudo-Nambu-Goldstone bosons associated with axial symmetry breaking along chiral symmetry breaking in the new gauge theory. A prominent consequence of the scenario is that there should be a Standard Model gauge singlet pseudo-Nambu-Goldstone boson with mass below 220GeV, which couples to two electroweak gauge bosons through the Wess-Zumino-Witten term, whose strength is thus determined by the dynamical scale of the new gauge theory. Other pseudo-Nambu-Goldstone bosons, charged under the electroweak gauge groups, also appear. Concerning the theoretical aspects, it is shown that the scalar quartic coupling can vanish at the Planck scale with the top quark pole mass as large as 172.5GeV, realizing the flatland scenario without being in tension with the current experimental data.
description: 42 pages, 7 figures. Version accepted for publication in Physical Review D
Phase Diagram of Restricted Boltzmann Machines and Generalised Hopfield Networks with Arbitrary Priors
Creators: name: Barra, Adriano
name: Genovese, Giuseppe
name: Sollich, Peter
name: Tantari, Daniele
Publisher: name: arXiv
Year: 2017
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Machine Learning (cs.LG)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Machine Learning (stat.ML)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Restricted Boltzmann Machines are described by the Gibbs measure of a bipartite spin glass, which in turn corresponds to the one of a generalised Hopfield network. This equivalence allows us to characterise the state of these systems in terms of retrieval capabilities, both at low and high load. We study the paramagnetic-spin glass and the spin glass-retrieval phase transitions, as the pattern (i.e. weight) distribution and spin (i.e. unit) priors vary smoothly from Gaussian real variables to Boolean discrete variables. Our analysis shows that the presence of a retrieval phase is robust and not peculiar to the standard Hopfield model with Boolean patterns. The retrieval region is larger when the pattern entries and retrieval units get more peaked and, conversely, when the hidden units acquire a broader prior and therefore have a stronger response to high fields. Moreover, at low load retrieval always exists below some critical temperature, for every pattern distribution ranging from the Boolean to the Gaussian case.
description: 18 pages, 9 figures; typos added
$q$-Generalized representation of the $d$-dimensional Dirac delta and $q$-Fourier transform
Creators: name: Sicuro, Gabriele
name: Tsallis, Constantino
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We discuss a generalized representation of the Dirac delta function in $d$ dimensions in terms of $q$-exponential functions. We apply this new representation to the study of the so-called $q$-Fourier transform, proving its invertibility for any value of $d$. We finally illustrate the effect of the $q$-deformation on the Gibbs phenomenon.
description: 6 pages, 3 figures
Modeling aggregation processes of Lennard-Jones particles via stochastic networks
Creators: name: Forman, Yakir
name: Cameron, Maria
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: FOS: Physical sciences
subject: 82C20, 82C22

description: We model an isothermal aggregation process of particles/atoms interacting according to the Lennard-Jones pair potential by mapping the energy landscapes of each cluster size $N$ onto stochastic networks, computing transition probabilities {from} the network for an $N$-particle cluster to the one for $N+1$, and connecting these networks into a single joint network. The attachment rate is a control parameter. The resulting network representing the aggregation of up to 14 particles contains {6427} vertices. It is not only time-irreversible but also reducible. To analyze its transient dynamics, we introduce the sequence of the expected initial and pre-attachment distributions and compute them for a wide range of attachment rates and three values of temperature. As a result, we find the {configurations most likely to be observed} in the process of aggregation for each cluster size. We examine the attachment process and conduct a structural analysis of the sets of local energy minima for every cluster size. We show that both processes taking place in the network, attachment and relaxation, lead to the dominance of icosahedral packing in small (up to 14 atom) clusters.
description: 28 pages, 13 figures, 6 tables
Exploring Biologically Inspired Mechanisms of Adversarial Robustness
Creators: name: Holzhausen, Konstantin
name: Merlid, Mia
name: Torvik, Håkon Olav
name: Malthe-Sørenssen, Anders
name: Lepperød, Mikkel Elle
Publisher: name: arXiv
Year: 2024
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: Artificial Intelligence (cs.AI)
subject: Neurons and Cognition (q-bio.NC)
subject: FOS: Computer and information sciences
subject: FOS: Biological sciences

description: Backpropagation-optimized artificial neural networks, while precise, lack robustness, leading to unforeseen behaviors that affect their safety. Biological neural systems do solve some of these issues already. Unlike artificial models, biological neurons adjust connectivity based on neighboring cell activity. Understanding the biological mechanisms of robustness can pave the way towards building trust worthy and safe systems. Robustness in neural representations is hypothesized to correlate with the smoothness of the encoding manifold. Recent work suggests power law covariance spectra, which were observed studying the primary visual cortex of mice, to be indicative of a balanced trade-off between accuracy and robustness in representations. Here, we show that unsupervised local learning models with winner takes all dynamics learn such power law representations, providing upcoming studies a mechanistic model with that characteristic. Our research aims to understand the interplay between geometry, spectral properties, robustness, and expressivity in neural representations. Hence, we study the link between representation smoothness and spectrum by using weight, Jacobian and spectral regularization while assessing performance and adversarial robustness. Our work serves as a foundation for future research into the mechanisms underlying power law spectra and optimally smooth encodings in both biological and artificial systems. The insights gained may elucidate the mechanisms that realize robust neural networks in mammalian brains and inform the development of more stable and reliable artificial systems.
Varieties with Ample Tangent Sheaves
Creators: name: Sieder, Philip
Publisher: name: arXiv
Year: 2017
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14N15

description: This paper generalises Mori's famous theorem about "Projective manifolds with ample tangent bundles" to normal projective varieties in the following way: A normal projective variety over $\mathbb{C}$ with ample tangent sheaf is isomorphic to the complex projective space.
description: 6 pages, Result of my master thesis supervised by Prof. Dr. Thomas Peternell, revised with minor text improvements, a remark to Theorem 3.2 and a new reference in the introduction
Exploring anomalous $hb\bar b$ and $h b\bar bγ$ couplings in the context of the LHC and an $e^+e^-$ collider
Creators: name: Dwivedi, Siddharth
name: Mondal, Subhadeep
name: Mukhopadhyaya, Biswarup
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the light of the 125 GeV Higgs ($h$) discovery at the Large Hadron Collider (LHC), one of the primary goals of the LHC and possible future colliders is to understand its interactions more precisely. Here we have studied the $h$-$b$-$\bar b$-$γ$ effective interaction terms arising out of gauge invariant dimension six operators in a model independent setting, as a potential source of new physics. Their role in some detectable final states have been compared with those coming from anomalous $h$-$b$-$\bar b$ interactions. We have considered the bounds coming from the existing collider and other low energy experimental data in order to derive constraints on the potential new physics couplings and predict possible collider signals for the two different new physics scenarios in the context of 14 TeV LHC and and a future $e^+e^-$ machine. We conclude that the anomalous $h$-$b$-$\bar b$-$γ$ coupling can be probed at the LHC at 14 TeV at the 3$σ$ level with an integrated luminosity of $\sim 2000~{\rm fb}^{-1}$, which an $e^+e^-$ collider can probe at the 3$σ$ level with $\sim 12(7)~{\rm fb}^{-1}$ at $\sqrt{s}=250(500)~{\rm GeV}$. It is also found that anomalous $h$-$b$-$\bar b$ interactions, subject to the existing LHC constraints, can not compete with the rates driven by $h$-$b$-$\bar b$-$γ$ effective interactions.
description: 29 pages, 11 figures and 9 tables
Appraisal of public Relations Strategies as A Tool for Resolving Petroleum Products Crisis in Nigeria
Creators: name: Nwanchor, Uchenna
Publisher: name: figshare
Year: 2023
Subjects: Communication studies
Communications and media policy
Communication and media studies not elsewhere classified

description: Nigeria is one of the Oil Producing and Exporting Countries (OPEC) whose crude oil is preferred by many non oil producing countries like Britain and the United States of America. A large chunk of the nation's foreign exchange earnings is generated from proceeds from crude oil, which led to the abysmal abandonment of her first ever known major income earner, Agriculture. while many of the nations who buy petroleum products from Nigeria are comfortable with their energy situation, Nigeria is engulfed in incessant crisis which has taken its toll on almost all sectors of the economy for many years.
All-thermal transistor based on stochastic switching
Creators: name: Sánchez, Rafael
name: Thierschmann, Holger
name: Molenkamp, Laurens W.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Fluctuations are strong in mesoscopic systems and have to be taken into account for the description of transport. We show that they can even be used as a resource for the operation of a system as a device. We use the physics of single-electron tunneling to propose a bipartite device working as a thermal transistor. Charge and heat currents in a two terminal conductor can be gated by thermal fluctuations from a third terminal to which it is capacitively coupled. The gate system can act as a switch that injects neither charge nor energy into the conductor hence achieving huge amplification factors. Non-thermal properties of the tunneling electrons can be exploited to operate the device with no energy consumption.
description: 5 pages, 3 figures. Published version
Search for new resonances decaying to pairs of merged diphotons in proton-proton collisions at $\sqrt{s}$ = 13 TeV
Creators: name: CMS Collaboration
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: A search is presented for an extended Higgs sector with two new particles, X and $ϕ$, in the process X $\to$ $ϕϕ$ $\to$ $(γγ)(γγ)$. Novel neural networks classify events with diphotons that are merged and determine the diphoton masses. The search uses LHC proton-proton collision data at $\sqrt{s}$ = 13 TeV collected with the CMS detector, corresponding to an integrated luminosity of 138 fb$^{-1}$. No evidence of such resonances is seen. Upper limits are set on the production cross section for $m_X$ between 300 and 3000 GeV and $m_ϕ/ m_X$ between 0.5 and 2.5%, representing the most sensitive search in this channel.
description: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables, including additional supplementary figures, can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/EXO-22-022 (CMS Public Pages)
GASP III. JO36: a case of multiple environmental effects at play?
Creators: name: Fritz, Jacopo
name: Moretti, Alessia
name: Gullieuszik, Marco
name: Poggianti, Bianca
name: Bruzual, Gustavo
name: Vulcani, Benedetta
name: Nicastro, Fabrizio
name: Jaffe', Yara
name: Sodi, Bernardo Cervantes
name: Bettoni, Daniela
name: Biviano, Andrea
name: Fasano, Giovanni
name: Charlot, Stephane
name: Bellhouse, Callum
name: Hau, George
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The so-called jellyfish galaxies are objects exhibiting disturbed morphology, mostly in the form of tails of gas stripped from the main body of the galaxy. Several works have strongly suggested ram pressure stripping to be the mechanism driving this phenomenon. Here, we focus on one of these objects, drawn from a sample of optically selected jellyfish galaxies, and use it to validate SINOPSIS, the spectral fitting code that will be used for the analysis of the GASP (GAs Stripping Phenomena in galaxies with MUSE) survey, and study the spatial distribution and physical properties of gas and stellar populations in this galaxy. We compare the model spectra to those obtained with GANDALF, a code with similar features widely used to interpret the kinematic of stars and gas in galaxies from IFU data. We find that SINOPSIS can reproduce the pixel-by-pixel spectra of this galaxy at least as good as GANDALF does, providing reliable estimates of the underlying stellar absorption to properly correct the nebular gas emission. Using these results, we find strong evidences of a double effect of ram pressure exerted by the intracluster medium onto the gas of the galaxy. A moderate burst of star formation, dating between 20 and 500 Myr ago and involving the outer parts of the galaxy more strongly than the inner regions, was likely induced by a first interaction of the galaxy with the intracluster medium. Stripping by ram pressure, plus probable gas depletion due to star formation, contributed to create a truncated ionized gas disk. The presence of an extended stellar tail on only one side of the disk, points instead to another kind of process, likely a gravitational interaction by a fly-by or a close encounter with another galaxy in the cluster.
description: ApJ in press, 26 pages, 18 figures
Forecasting the Impact of Stellar Activity on Transiting Exoplanet Spectra
Creators: name: Zellem, Robert T.
name: Swain, Mark R.
name: Roudier, Gael
name: Shkolnik, Evgenya L.
name: Creech-Eakman, Michelle J.
name: Ciardi, David R.
name: Line, Michael R.
name: Iyer, Aishwarya R.
name: Bryden, Geoffrey
name: Llama, Joe
name: Fahy, Kristen A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Exoplanet host star activity, in the form of unocculted star spots or faculae, alters the observed transmission and emission spectra of the exoplanet. This effect can be exacerbated when combining data from different epochs if the stellar photosphere varies between observations due to activity. redHere we present a method to characterize and correct for relative changes due to stellar activity by exploiting multi-epoch ($\ge$2 visits/transits) observations to place them in a consistent reference frame. Using measurements from portions of the planet's orbit where negligible planet transmission or emission can be assumed, we determine changes to the stellar spectral amplitude. With the analytical methods described here, we predict the impact of stellar variability on transit observations. Supplementing these forecasts with Kepler-measured stellar variabilities for F-, G-, K-, and M-dwarfs, and predicted transit precisions by JWST's NIRISS, NIRCam, and MIRI, we conclude that stellar activity does not impact infrared transiting exoplanet observations of most presently-known or predicted TESS targets by current or near-future platforms, such as JWST.
description: ApJ accepted; updated to address referee's comments; 17 pages including references, 4 figures; comments welcome
Alignment of a Vector Magnetometer to an Optical Prism
Creators: name: Dietrich, M. R.
name: Bailey, K. G.
name: O'Connor, T. P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: A method for alignment of a vector magnetometer to a rigidly attached prism is presented. This enables optical comparison of the magnetometer axes to physical surfaces in an apparatus, and thus an absolute determination of the magnetic field direction in space. This is in contrast with more common techniques, which focus on precise determination of the relative angles between magnetometer axes, and so are more suited to measuring differences in the direction of magnetic fields. Here we demonstrate precision better than 500 $μ$rad on a fluxgate magnetometer, which also gives the coil orthogonality errors to a similar precision. The relative sensitivity of the 3 axes is also determined, with precision of about 5$\times 10^{-4}$.
description: 4 pages, 2 figures
Affine and topological structural entropies in granular statistical mechanics: explicit calculations and equation of state
Creators: name: Amitai, Shahar
name: Blumenfeld, Raphael
Publisher: name: arXiv
Year: 2017
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We identify two orthogonal sources of structural entropy in rattler-free granular systems - affine, involving structural changes that only deform the contact network, and topological, corresponding to different topologies of the contact network. We show that a recently developed connectivity-based granular statistical mechanics separates the two naturally by identifying the structural degrees of freedom with spanning trees on the graph of the contact network. We extend the connectivity-based formalism to include constraints on, and correlations between, degrees of freedom as interactions between branches of the spanning tree. We then use the statistical mechanics formalism to calculate the partition function generally and the different entropies in the high-angoricity limit. We also calculate the degeneracy of the affine entropy and a number of expectation values. From the latter, we derive an equipartition principle and an equation of state relating the macroscopic volume and boundary stress to the analogue of the temperature, the contactivity.
description: 14 pages, 9 figures
Combining electronic structure and many-body theory with large data-bases: a method for predicting the nature of 4f states in Ce compounds
Creators: name: Herper, Heike. C.
name: Ahmed, Towfiq.
name: Wills, John. M.
name: Di Marco, Igor
name: Björkman, T.
name: Iuşan, Diana
name: Balatsky, Alexander. V.
name: Eriksson, Olle
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Here we present the first large scale investigation of electronic properties and correlated magnetism in Ce-based compounds accompanied by a systematic study of the electronic structure and 4f-hybridization function of a large body of Ce compounds. We systematically study the electronic structure and 4f-hybridization function of a large body of Ce compounds with the goal of elucidating the nature of the 4f states and their interrelation with the measured Kondo energy in these compounds. The hybridization function has been analyzed for more than 350 data sets of cubic Ce compounds using electronic structure theory that relies on a full-potential approach. We demonstrate that the strength of the hybridization function, evaluated in this way, allows us to draw precise conclusions about the degree of localization of the 4f states in these compounds. The theoretical results are entirely consistent with all experimental information, relevant to the degree of 4f localization for all investigated materials. Furthermore, a more detailed analysis of the electronic structure and the hybridization function allows us to make precise statements about Kondo correlations in these systems. The calculated hybridization functions, together with the corresponding density of states, reproduce the expected exponential behavior of the observed Kondo temperatures and prove a consistent trend in real materials. This trend allows us to predict which systems may be correctly identified as Kondo systems. A strong anti-correlation between the size of the hybridization function and the volume of the systems has been observed. Our approach demonstrates the predictive power of materials informatics when a large number of materials is used to establish significant trends which can be used to design new materials with desired properties.
description: 28 pages, 6 figures, regular article, plus supplement with 4 figures and a long table
The Minimal Geometric Deformation Approach: a brief introduction
Creators: name: Ovalle, J
name: Casadio, R
name: Sotomayor, A
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 review the basic elements of the Minimal Geometric Deformation approach in details. This method has been successfully used to generate brane-world configurations from general relativistic perfect fluid solutions.
description: Brief review; minor corrections; references added
Measurement Matrix Design for Phase Retrieval Based on Mutual Information
Creators: name: Shlezinger, Nir
name: Dabora, Ron
name: Eldar, Yonina C.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: In phase retrieval problems, a signal of interest (SOI) is reconstructed based on the magnitude of a linear transformation of the SOI observed with additive noise. The linear transform is typically referred to as a measurement matrix. Many works on phase retrieval assume that the measurement matrix is a random Gaussian matrix, which, in the noiseless scenario with sufficiently many measurements, guarantees invertability of the transformation between the SOI and the observations, up to an inherent phase ambiguity. However, in many practical applications, the measurement matrix corresponds to an underlying physical setup, and is therefore deterministic, possibly with structural constraints. In this work we study the design of deterministic measurement matrices, based on maximizing the mutual information between the SOI and the observations. We characterize necessary conditions for the optimality of a measurement matrix, and analytically obtain the optimal matrix in the low signal-to-noise ratio regime. Practical methods for designing general measurement matrices and masked Fourier measurements are proposed. Simulation tests demonstrate the performance gain achieved by the proposed techniques compared to random Gaussian measurements for various phase recovery algorithms.
description: This paper was presented in part at the 2017 International Symposium on Information Theory
Pungitius laevis
Creators: name: Béarez, Philippe
name: Pruvost, Patrice
name: Feunteun, Eric
name: Iglésias, Samuel P.
name: Francour, Patrice
name: Causse, Romain
name: De Mazieres, Jeanne
name: Tercerie, Sandrine
name: Bailly, Nicolas
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Gasterosteiformes
Gasterosteidae
Pungitius
Pungitius laevis

description: Pungitius laevis (Cuvier, 1829) – Smoothtail ninespine  stickleback – Épinochette à peau douce
Some primarily freshwater species are sometimes cited geographically from “marine” environment. However, it is often by accident (fishes washed out by a flood, and found at sea in the plume of freshwater at the surface), or in very restricted areas under the strong influence of a freshwater source. We did not include those in this list.
 9 Most probably extinct in France.
description: Published as part of Béarez, Philippe, Pruvost, Patrice, Feunteun, Eric, Iglésias, Samuel P., Francour, Patrice, Causse, Romain, De Mazieres, Jeanne, Tercerie, Sandrine & Bailly, Nicolas, 2017, Checklist of the marine fishes from metropolitan France, pp. 351-371 in Cybium 41 (4) on page 371, DOI: 10.26028/cybium/2017-414-006, http://zenodo.org/record/13479447
On the projected mass distribution around galaxy clusters : a Lagrangian theory of harmonic power spectra
Creators: name: Codis, Sandrine
name: Gavazzi, Raphael
name: Pichon, Christophe
name: Gouin, Celine
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Gravitational lensing allows to quantify the angular distribution of the convergence field around clusters of galaxies to constrain their connectivity to the cosmic web. We describe in this paper the corresponding theory in Lagrangian space where analytical results can be obtained by identifying clusters to peaks in the initial field. We derive the three-point Gaussian statistics of a two-dimensional field and its first and second derivatives. The formalism allows us to study the statistics of the field in a shell around a central peak, in particular its multipolar decomposition. The peak condition is shown to significantly remove power from the dipolar contribution and to modify the monopole and quadrupole. As expected, higher order multipoles are not significantly modified by the constraint. Analytical predictions are successfully checked against measurements in Gaussian random fields. The effect of substructures and radial weighting is shown to be small and does not change the qualitative picture. The non-linear evolution is shown to induce a non-linear bias of all multipoles proportional to the cluster mass.We predict the Gaussian and weakly non-Gaussian statistics of multipolar moments of a two-dimensional field around a peak as a proxy for the azimuthal distribution of the convergence field around a cluster of galaxies. A quantitative estimate of this multipolar decomposition of the convergence field around clusters in numerical simulations of structure formation and in observations will be presented in two forthcoming papers.
description: 13 pages, matched version accepted for publication in A&A
Using magnetic dynamics to measure the spin gap in a candidate Kitaev material
Creators: name: Jiang, Xinyi
name: Qiu, Qingzheng
name: Peng, Cheng
name: Jang, Hoyoung
name: Chen, Wenjie
name: Jin, Xianghong
name: Yue, Li
name: Lee, Byungjune
name: Park, Sang-Youn
name: Kim, Minseok
name: Kim, Hyeong-Do
name: Cai, Xinqiang
name: Li, Qizhi
name: Dong, Tao
name: Wang, Nanlin
name: Turner, Joshua J.
name: Li, Yuan
name: Wang, Yao
name: Peng, Yingying
Publisher: name: arXiv
Year: 2024
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Materials potentially hosting Kitaev spin-liquid states are considered crucial for realizing topological quantum computing. However, the intricate nature of spin interactions within these materials complicates the precise measurement of low-energy spin excitations indicative of fractionalized excitations. Using Na$_{2}$Co$_2$TeO$_{6}$ as an example, we study these low-energy spin excitations using the time-resolved resonant elastic x-ray scattering (tr-REXS). Our observations unveil remarkably slow spin dynamics at the magnetic peak, whose recovery timescale is several nanoseconds. This timescale aligns with the extrapolated spin gap of $\sim$ 1 $μ$eV, obtained by density matrix renormalization group (DMRG) simulations in the thermodynamic limit. The consistency demonstrates the efficacy of tr-REXS in discerning low-energy spin gaps inaccessible to conventional spectroscopic techniques.
description: 9 pages, 6 figures
Magnetic Field-Constrained Ensemble Image Segmentation of Coronal Holes in Chromospheric Observations
Creators: name: Landeros, Jaime A.
name: Kirk, Michael S.
name: Arge, C. Nick
name: Boucheron, Laura E.
name: Zhang, Jie
name: Uritsky, Vadim M.
name: Grajeda, Jeremy A.
name: Dupertuis, Matthew
Publisher: name: arXiv
Year: 2024
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Coronal Holes (CHs) are large-scale, low-density regions in the solar atmosphere which may expel high-speed solar wind streams that incite hazardous, geomagnetic storms. Coronal and solar wind models can predict these high-speed streams and the performance of the coronal model can be validated against segmented CH boundaries. We present a novel method named Sub-Transition Region Identification of Ensemble Coronal Holes (STRIDE-CH) to address prominent challenges in segmenting CHs with Extreme Ultraviolet (EUV) imagery. Ground-based, chromospheric He I 10830 Å line imagery and underlying Fe I photospheric magnetograms are revisited to disambiguate CHs from filaments and quiet Sun, overcome obscuration by coronal loops, and complement established methods in the community which use space-borne, coronal EUV observations. Classical computer vision techniques are applied to constrain the radiative and magnetic properties of detected CHs, produce an ensemble of boundaries, and compile these boundaries in a confidence map that quantifies the likelihood of CH presence throughout the solar disk. This method is science-enabling towards future studies of CH formation and variability from a mid-atmospheric perspective.
description: 23 pages, 7 figures
Single shot ultrafast all optical magnetization switching of ferromagnetic Co/Pt multilayers
Creators: name: Gorchon, Jon
name: Lambert, Charles-Henri
name: Yang, Yang
name: Pattabi, Akshay
name: Wilson, Richard B.
name: Salahuddin, Sayeef
name: Bokor, Jeffrey
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In a number of recent experiments, it has been shown that femtosecond laser pulses can control magnetization on picosecond timescales, which is at least an order of magnitude faster compared to conventional magnetization dynamics. Among these demonstrations, one material system (GdFeCo ferromagnetic films) is particularly interesting, as deterministic toggle-switching of the magnetic order has been achieved without the need of any symmetry breaking magnetic field. This phenomenon is often referred to as all optical switching (AOS). However, so far, GdFeCo remains the only material system where such deterministic switching has been observed. When extended to ferromagnetic systems, which are of greater interest in many technological applications, only a partial effect can be achieved, which in turn requires repeated laser pulses for full switching. However, such repeated pulsing is not only energy hungry, it also negates the speed advantage of AOS. Motivated by this problem, we have developed a general method for single-shot, picosecond timescale, complete all optical switching of ferromagnetic materials. We demonstrate that in exchange-coupled layers of Co/Pt and GdFeCo, single shot, switching of the ferromagnetic Co/Pt layer is achieved within 7 picoseconds after irradiation by a femtosecond laser pulse. We believe that this approach will greatly expand the range of materials and applications for ultrafast magnetic switching.
description: 11 pages, 3 figures, supplementary materials
An Investigation of the Rotational Properties of Magnetic Chemically Peculiar Stars
Creators: name: Netopil, Martin
name: Paunzen, Ernst
name: Hümmerich, Stefan
name: Bernhard, Klaus
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The magnetic chemically peculiar (mCP) stars of the upper main sequence exhibit strong, globally-organised magnetic fields which are inclined to the rotational axis and facilitate the development of surface abundance inhomogeneities resulting in photometric and spectroscopic variability. Therefore, mCP stars are perfectly suited for a direct measurement of the rotational period without the need for any additional calibrations. We have investigated the rotational properties of mCP stars based on an unprecedentedly large sample consisting of more than 500 objects with known rotational periods. Using precise parallaxes from the Hipparcos and Gaia satellite missions, well-established photometric calibrations and state-of-the-art evolutionary models, we have determined the location of our sample stars in the Hertzsprung-Russell diagram and derived astrophysical parameters such as stellar masses, effective temperature, radii, inclinations and critical rotational velocities. We have confirmed the conservation of angular momentum during the main sequence evolution; no signs of additional magnetic braking were found. The inclination angles of the rotational axes are randomly distributed, although an apparent excess of fast rotators with comparable inclination angles has been observed. We have found a rotation rate of $\upsilon/\upsilon_{\rm crit} \geq 0.5$ for several stars, whose characteristics cannot be explained by current models. For the first time, we have derived the relationship between mass and rotation rate of mCP stars, and provide an analysis that links mass and rotation with magnetic field strength. Our sample is unique and offers crucial input for forthcoming evolutionary models that include the effects of magnetic fields for upper main sequence stars.
description: 13 pages, 9 figures, accepted for publication in MNRAS, updated to match the published version