nils-herrmann/clean_scirepeval huggingface dataset:
Extracting spatial information from networks with low-order eigenvectors

We consider the problem of inferring meaningful spatial information in networks from incomplete information on the connection intensity between the nodes of the network. We consider two spatially distributed networks: a population migration flow network within the US, and a network of mobile phone calls between cities in Belgium. For both networks we use the eigenvectors of the Laplacian matrix constructed from the link intensities to obtain informative visualizations and capture natural geographical subdivisions. We observe that some low order eigenvectors localize very well and seem to reveal small geographically cohesive regions that match remarkably well with political and administrative boundaries. We discuss possible explanations for this observation by describing diffusion maps and localized eigenfunctions. In addition, we discuss a possible connection with the weighted graph cut problem, and provide numerical evidence supporting the idea that lower order eigenvectors point out local cuts in the network. However, we do not provide a formal and rigorous justification for our observations.
A COMPACT DEGENERATE PRIMARY-STAR PROGENITOR OF SN 2011fe

While a white dwarf (WD) is, from a theoretical perspective, the most plausible primary star of a Type Ia supernova (SN Ia), many other candidates have not been formally ruled out. Shock energy deposited in the envelope of any exploding primary contributes to the early SN brightness and, since this radiation energy is degraded by expansion after the explosion, the diffusive luminosity depends on the initial primary radius. We present a new non-detection limit of the nearby SN Ia 2011fe, obtained at a time that appears to be just 4 hr after explosion, allowing us to directly constrain the initial primary radius (Rp). Coupled with the non-detection of a quiescent X-ray counterpart and the inferred synthesized 56Ni mass, we show that Rp ≲ 0.02 R☉ (a factor of five smaller than previously inferred), that the average density of the primary must be ρp > 104 g cm−3, and that the effective temperature must be less than a few × 105 K. This rules out hydrogen-burning main-sequence stars and giants. Constructing the helium-burning and carbon-burning main sequences, we find that such objects are also excluded. By process of elimination, we find that only degeneracy-supported compact objects—WDs and neutron stars—are viable as the primary star of SN 2011fe. With few caveats, we also restrict the companion (secondary) star radius to Rc ≲ 0.1 R☉, excluding Roche-lobe overflowing red giant and main-sequence companions to high significance.
Electronic structure of nickelates: From two-dimensional heterostructures to three-dimensional bulk materials

Reduced dimensionality and strong electronic correlations, which are among the most important ingredients for cupratelike high-Tc superconductivity, characterize also the physics of nickelate-based heterostructures. Starting from the local-density approximation we arrive at a simple two-band model for quasi-two-dimensional 2D LaNiO3 /LaAlO3 heterostructures and extend it by introducing an appropriate hopping in the z direction to describe the dimensional crossover to three dimensions 3D. Using dynamical mean-field theory, we study the effects of electronic correlations with increasing interaction strength along the crossover from 2D to 3D. Qualitatively, the effects of electronic correlations are surprisingly similar, albeit quantitatively larger interaction strengths are required in three dimensions for getting a Mott-Hubbard insulating state. The exchange parameters of an effective Kugel-Khomskii-type spin-orbital model are also derived and reveal strong antiferromagnetic tendencies.
A new simple class of superpotentials in SUSY quantum mechanics

In this work, we introduce the class of quantum mechanics superpotentials W(x) = gε(x)x2n and study in detail the cases n = 0 and 1. The n = 0 superpotential is shown to lead to the known problem of two supersymmetrically related Dirac delta potentials (well and barrier). The n = 1 case results in the potentials V±(x) = g2x4 ± 2g|x|. For V−, we present the exact ground-state solution and study the excited states by a variational technique. Starting from the ground state of V− and using logarithmic perturbation theory, we study the ground states of V+ and also of V(x) = g2x4 and compare the result obtained in this new way with other results for this last potential in the literature.
More Voices Than Ever? Quantifying Media Bias in Networks

Social media, such as blogs, are often seen as democratic entities that allow more voices to be heard than the conventional mass or elite media. Some also feel that social media exhibits a balancing force against the arguably slanted elite media. A systematic comparison between social and mainstream media is necessary but challenging due to the scale and dynamic nature of modern communication. Here we propose empirical measures to quantify the extent and dynamics of social (blog) and mainstream (news) media bias. We focus on a particular form of bias---coverage quantity---as applied to stories about the 111th US Congress. We compare observed coverage of Members of Congress against a null model of unbiased coverage, testing for biases with respect to political party, popular front runners, regions of the country, and more. Our measures suggest distinct characteristics in news and blog media. A simple generative model, in agreement with data, reveals differences in the process of coverage selection between the two media.
HOW DO STAR-FORMING GALAXIES AT z > 3 ASSEMBLE THEIR MASSES?

We investigate how star-forming galaxies typically assemble their masses at high redshift. Taking advantage of the deep multi-wavelength coverage of the GOODS data set, we select two of the largest samples of high-redshift star-forming galaxies based on their UV colors and measure stellar mass of individual galaxies. We use template-fitting photometry to obtain optimal estimates of the fluxes in lower-resolution ground-based and Spitzer images using prior information about galaxy positions, shapes, and orientations. By combining the data and realistic simulations to understand measurement errors and biases, we make a statistically robust determination of stellar mass function (SMF) of the UV-selected star-forming galaxies at z ∼ 4 and 5. We report a broad correlation between stellar mass and UV luminosity, such that more UV-luminous galaxies are, on average, also more massive. However, we show that the correlation has a substantial intrinsic scatter, particularly for UV-faint galaxies, evidenced by the fact there is a non-negligible number of UV faint but massive galaxies. Furthermore, we find that the low-mass end of the SMF does not rise as steeply as the UV luminosity function (αUVLF  ≈  − (1.7–1.8) while αSMF  ≈  − (1.3–1.4)) of the same galaxies. In a smooth and continuous formation scenario where star formation rates (SFRs) are sustained at the observed rates for a long time, these galaxies would have accumulated more stellar mass (by a factor of ≈3) than observed and therefore the SMF would mirror more closely that of the UV luminosity function. The relatively shallow slope of the SMF is due to the fact that many of the UV-selected galaxies are not massive enough, and therefore are too faint in their rest-frame optical bands, to be detected in the current observations. Our results favor a more episodic formation history in which SFRs of low-mass galaxies vary significantly over cosmic time, a scenario currently favored by galaxy clustering. Our findings for the UV-faint galaxies at high redshift are in contrast with previous studies on more UV-luminous galaxies, which exhibit a tighter SFR–Mstar correlation. The discrepancy may suggest that galaxies at different luminosities may have different evolutionary paths. Such a scenario presents a nontrivial test to theoretical models of galaxy formation.
THE FIRST INFRARED STUDY OF THE CLOSE ENVIRONMENT OF A LONG GAMMA-RAY BURST*

We present a characterization of the close environment of GRB 980425 based on 5-160 μm spectro-imaging obtained with Spitzer. The gamma-ray burst GRB 980425 occurred in a nearby (z = 0.0085) SBc-type dwarf galaxy at a projected distance of 900 pc from an H II region with strong signatures of Wolf-Rayet (WR) stars. While this "WR region" produces less than 5% of the B-band emission of the host, we find that it is responsible for 45% ± 10% of the total infrared luminosity, with a maximum contribution reaching 75% at 25-30 μm. This atypical property is rarely observed among morphologically relaxed dwarfs, suggesting a strong causal link with the gamma-ray burst (GRB) event. The luminosity of the WR region (L_(8-1000 μm) = 4.6 × 10^8 L_☉), the peak of its spectral energy distribution at ≾100 μm, and the presence of highly ionized emission lines (e.g., [Ne III]) also reveal extremely young (<5 Myr) star-forming activity, with a typical timescale of only 47 Myr to double the stellar mass already built. Finally, the mid-IR over B-band luminosity ratio in this region is substantially higher than in star-forming galaxies with similar L_(IR), but it is lower than in young dust-enshrouded stellar clusters. Considering the modest obscuration measured from the silicate features (τ_(9.7 μm) ~ 0.015), this suggests that the WR region is dominated by one or several star clusters that have either partly escaped or cleared out their parent molecular cloud. Combined with the properties characterizing the whole population of GRB hosts, our results reinforce the idea that long GRBs mostly happen within or in the vicinity of relatively unobscured galactic regions harboring very recent star formation.
Smoothed Particle Hydrodynamics: Things I wish my mother taught me

I discuss the key features of Smoothed Particle Hydrodynamics (SPH) as a numerical method - in particular the key differences between SPH and more standard grid based approaches - that are important to the practitioner. These include the exact treatment of advection, the absence of intrinsic dissipation, exact conservation and more subtle properties that arise from its Hamiltonian formulation such as the existence of a minimum energy state for the particles. The implications of each of these are discussed, showing how they can be both advantages and disadvantages.
Protection of existing and potential observatory sites: Triennial report 2009-2012 of IAU Commission 50

(abridged) The activities of the Commission have continued to focus on controlling unwanted light and radio emissions at observatory sites, monitoring of conditions at observatory sites, and education and outreach. Commission members have been active in securing new legislation in several locations to further the protection of observatory sites as well as in the international regulation of the use of the radio spectrum and the protection of radio astronomical observations. 
In 2009, at its XXVII General Assembly in Rio de Janeiro, the IAU passed Resolution B5 in Defence of the Night Sky and the Right to Starlight. The Resolution encourages IAU members to assist in raising public awareness about the contents and objectives of the International Conference in Defence of the Quality of the Night Sky and the Right to Observe Stars [this http URL], in particular the importance of preserving access to an unpolluted night sky for all mankind.
Dark-matter admixed neutron stars

We study the hydrostatic equilibrium configuration of an admixture of degenerate dark matter and normal nuclear matter by using a general relativistic two-fluid formalism. We consider non- self-annihilating dark matter particles of mass ~ 1 GeV. The mass-radius relations and moments of inertia of these dark-matter admixed neutron stars are investigated and the stability of these stars is demonstrated by performing a radial perturbation analysis. We find a new class of compact stars which consists of a small normal matter core with radius of a few km embedded in a ten-kilometer- sized dark matter halo. These stellar objects may be observed as extraordinarily small neutron stars that are incompatible with realistic nuclear matter models.
Dynamical classes of collective attention in twitter

Micro-blogging systems such as Twitter expose digital traces of social discourse with an unprecedented degree of resolution of individual behaviors. They offer an opportunity to investigate how a large-scale social system responds to exogenous or endogenous stimuli, and to disentangle the temporal, spatial and topical aspects of users' activity. Here we focus on spikes of collective attention in Twitter, and specifically on peaks in the popularity of hashtags. Users employ hashtags as a form of social annotation, to define a shared context for a specific event, topic, or meme. We analyze a large-scale record of Twitter activity and find that the evolution of hashtag popularity over time defines discrete classes of hashtags. We link these dynamical classes to the events the hashtags represent and use text mining techniques to provide a semantic characterization of the hashtag classes. Moreover, we track the propagation of hashtags in the Twitter social network and find that epidemic spreading plays a minor role in hashtag popularity, which is mostly driven by exogenous factors.
Measurement of b hadron production fractions in 7 TeV pp collisions

Measurements of $b$ hadron production ratios in proton-proton collisions at a centre-of-mass energy of 7 TeV with an integrated luminosity of 3 pb$^{-1}$ are presented. We study the ratios of strange $B$ meson to light $B$ meson production $f_s/(f_u+f_d)$ and $Lambda_b^0$ baryon to light $B$ meson production $f_{Lambda_b}/(f_u+f_d)$ as a function of the charmed hadron-muon pair transverse momentum $p_T$ and the $b$ hadron pseudorapidity $eta$, for $p_T$ between 0 and 14 GeV and $eta$ between 2 and 5. We find that $f_s/(f_u+f_d)$ is consistent with being independent of $p_{rm T}$ and $eta$, and we determine $f_s/(f_u+f_d)$ = 0.134$pm$ 0.004 $^{+0.011}_{-0.010}$, where the first error is statistical and the second systematic. The corresponding ratio $f_{Lambda_b}/(f_u+f_d)$ is found to be dependent upon the transverse momentum of the charmed hadron-muon pair, $f_{Lambda_b}/(f_u+f_d)=(0.404pm 0.017 (stat) pm 0.027 (syst) pm 0.105 (Br))times[1 -(0.031 pm 0.004 (stat) pm 0.003 (syst))times p_T(GeV)]$, where Br reflects an absolute scale uncertainty due to the poorly known branching fraction Br(Lambda_c^+ to pK^-pi^+)$. We extract the ratio of strange $B$ meson to light neutral $B$ meson production $f_s/f_d$ by averaging the result reported here with two previous measurements derived from the relative abundances of $bar{B}_s to D_S^+ pi ^-$ to $bar{B}^0 to D^+K^-$ and $bar{B}^0 to D^+pi^-$. We obtain $f_s/f_d=0.267^{+0.021}_{-0.020}$.
Constraints on the pMSSM from LAT observations of dwarf spheroidal galaxies

We examine the ability for the Large Area Telescope (LAT) to constrain Minimal Supersymmetric Standard Model (MSSM) dark matter through a combined analysis of Milky Way dwarf spheroidal galaxies. We examine the Lightest Supersymmetric Particles (LSPs) for a set of {approx}71k experimentally valid supersymmetric models derived from the phenomenological-MSSM (pMSSM). We find that none of these models can be excluded at 95% confidence by the current analysis; nevertheless, many lie within the predicted reach of future LAT analyses. With two years of data, we find that the LAT is currently most sensitive to light LSPs (mLSP < 50 GeV) annihilating into {tau}-pairs and heavier LSPs annihilating into b{bar b}. Additionally, we find that future LAT analyses will be able to probe some LSPs that form a sub-dominant component of dark matter. We directly compare the LAT results to direct detection experiments and show the complementarity of these search methods.
The influence of the network topology on epidemic spreading

The influence of the network's structure on the dynamics of spreading processes has been extensively studied in the last decade. Important results that partially answer this question show a weak connection between the macroscopic behavior of these processes and specific structural properties in the network, such as the largest eigenvalue of a topology related matrix. However, little is known about the direct influence of the network topology on the microscopic level, such as the influence of the (neighboring) network on the probability of a particular node's infection. To answer this question, we derive both an upper and a lower bound for the probability that a particular node is infective in a susceptible-infective-susceptible model for two cases of spreading processes: reactive and contact processes. The bounds are derived by considering the n-hop neighborhood of the node; the bounds are tighter as one uses a larger n-hop neighborhood to calculate them. Consequently, using local information for different neighborhood sizes, we assess the extent to which the topology influences the spreading process, thus providing also a strong macroscopic connection between the former and the latter. Our findings are complemented by numerical results for a real-world email network. A very good estimate for the infection density ρ is obtained using only two-hop neighborhoods, which account for 0.4% of the entire network topology on average.
From Caesar to Twitter: An Axiomatic Approach to Elites of Social Networks

In many societies there is an elite, a relatively small group of powerful individuals that is well-connected and highly influential. Since the ancient days of Julius Caesar's senate of Rome to the recent days of celebrities on Twitter, the size of the elite is a result of conflicting social forces competing to increase or decrease it. 
The main contribution of this paper is the answer to the question how large the elite is at equilibrium. We take an axiomatic approach to solve this: assuming that an elite exists and it is influential, stable and either minimal or dense, we prove that its size must be $\Theta(\sqrt{m})$ (where $m$ is the number of edges in the network). 
As an approximation for the elite, we then present an empirical study on nine large real-world networks of the subgraph formed by the highest degree nodes, also known as the rich-club. Our findings indicate that elite properties such as disproportionate influence, stability and density of $\Theta(\sqrt{m})$-rich-clubs are universal properties and should join a growing list of common phenomena shared by social networks and complex systems such as "small world," power law degree distributions, high clustering, etc.
Linking to Data - Effect on Citation Rates in Astronomy

Is there a difference in citation rates between articles that were published with links to data and articles that were not? Besides being interesting from a purely academic point of view, this question is also highly relevant for the process of furthering science. Data sharing not only helps the process of verification of claims, but also the discovery of new findings in archival data. However, linking to data still is a far cry away from being a "practice", especially where it comes to authors providing these links during the writing and submission process. You need to have both a willingness and a publication mechanism in order to create such a practice. Showing that articles with links to data get higher citation rates might increase the willingness of scientists to take the extra steps of linking data sources to their publications. In this presentation we will show this is indeed the case: articles with links to data result in higher citation rates than articles without such links. The ADS is funded by NASA Grant
Living in Living Cities

This article presents an overview of current and potential applications of living technology to some urban problems. Living technology can be described as technology that exhibits the core features of living systems. These features can be useful to solve dynamic problems. In particular, urban problems concerning mobility, logistics, telecommunications, governance, safety, sustainability, and society and culture are presented, and solutions involving living technology are reviewed. A methodology for developing living technology is mentioned, and supraoptimal public transportation systems are used as a case study to illustrate the benefits of urban living technology. Finally, the usefulness of describing cities as living systems is discussed.
Is de Sitter space a fermion

Following up on a recent model yielding fermionic geometries, I turn to more familiar territory to address the question of statistics in purely geometric theories. Working in the gauge formulation of gravity, where geometry is characterized by a symmetry broken Cartan connection, I give strong evidence to suggest that de Sitter space itself, and a class of de Sitter-like geometries, can be consistently quantized fermionically. By this I mean that de Sitter space can be quantized such that the wavefunctional picks up an overall minus sign under a $2\pi$ rotational diffeomorphism. Surprisingly, the underlying mathematics is the same as that of the Skyrme model for strongly interacting baryons. This promotes the question {\it "Is geometry bosonic or fermionic?"} beyond the realm of the rhetorical and places it on uncomfortably familiar ground.
Recipe recommendation using ingredient networks

The recording and sharing of cooking recipes, a human activity dating back thousands of years, naturally became an early and prominent social use of the web. The resulting online recipe collections are repositories of ingredient combinations and cooking methods whose large-scale and variety yield interesting insights about both the fundamentals of cooking and user preferences. At the level of an individual ingredient we measure whether it tends to be essential or can be dropped or added, and whether its quantity can be modified. We also construct two types of networks to capture the relationships between ingredients. The complement network captures which ingredients tend to co-occur frequently, and is composed of two large communities: one savory, the other sweet. The substitute network, derived from user-generated suggestions for modifications, can be decomposed into many communities of functionally equivalent ingredients, and captures users' preference for healthier variants of a recipe. Our experiments reveal that recipe ratings can be well predicted with features derived from combinations of ingredient networks and nutrition information.
The ADS All-Sky Survey

The ADS All-Sky Survey (ADSASS) is an ongoing effort aimed at turning the NASA Astrophysics Data System (ADS), widely known for its unrivaled value as a literature resource for astronomers, into a data resource. The ADS is not a data repository per se, but it implicitly contains valuable holdings of astronomical data, in the form of images, tables and object references contained within articles. The objective of the ADSASS effort is to extract these data and make them discoverable and available through existing data viewers. The resulting ADSASS data layer promises to greatly enhance workflows and enable new research by tying astronomical literature and data assets into one resource.