nils-herrmann/clean_scirepeval huggingface dataset:
Coarse-Grained Modeling of a Deformable Nematic Vesicle

We develop a coarse-grained particle-based model to simulate membranes with nematic liquid-crystal order. The coarse-grained particles form vesicles which, at low temperature, have orientational order in the local tangent plane. As the strength of coupling between the nematic director and the vesicle curvature increases, the vesicles show a morphology transition from spherical to prolate and finally to a tube. We also observe the shape and defect arrangement around the tips of the prolate vesicle.
The Fine-Tuning of the Universe for Intelligent Life

The fine-tuning of the universe for intelligent life has received a great deal of attention in recent years, both in the philosophical and scientific literature. The claim is that in the space of possible physical laws, parameters and initial conditions, the set that permits the evolution of intelligent life is very small. I present here a review of the scientific literature, outlining cases of fine-tuning in the classic works of Carter, Carr and Rees, and Barrow and Tipler, as well as more recent work. To sharpen the discussion, the role of the antagonist will be played by Victor Stenger's recent book The Fallacy of Fine-Tuning: Why the Universe is Not Designed for Us. Stenger claims that all known fine-tuning cases can be explained without the need for a multiverse. Many of Stenger's claims will be found to be highly problematic. We will touch on such issues as the logical necessity of the laws of nature; objectivity, invariance and symmetry; theoretical physics and possible universes; entropy in cosmology; cosmic inflation and initial conditions; galaxy formation; the cosmological constant; stars and their formation; the properties of elementary particles and their effect on chemistry and the macroscopic world; the origin of mass; grand unified theories; and the dimensionality of space and time. I also provide an assessment of the multiverse, noting the significant challenges that it must face. I do not attempt to defend any conclusion based on the fine-tuning of the universe for intelligent life. This paper can be viewed as a critique of Stenger's book, or read independently.
Buckling of Carbon Nanotubes: A State of the Art Review

The nonlinear mechanical response of carbon nanotubes, referred to as their “buckling" behavior, is a major topic in the nanotube research community. Buckling means a deformation process in which a large strain beyond a threshold causes an abrupt change in the strain energy vs. deformation profile. Thus far, much effort has been devoted to analysis of the buckling of nanotubes under various loading conditions: compression, bending, torsion, and their certain combinations. Such extensive studies have been motivated by (i) the structural resilience of nanotubes against buckling and (ii) the substantial influence of buckling on their physical properties. In this contribution, I review the dramatic progress in nanotube buckling research during the past few years.
Recollimation boundary layers in relativistic jets

We study the collimation of relativistic hydrodynamic jets by the pressure of an ambient medium in the limit where the jet interior has lost causal contact with its surroundings. For a jet with an ultrarelativistic equation of state and external pressure that decreases as a power of spherical radius, p / r � , the jet interior will lose causal contact when η > 2. However, the outer layers of the jet gradually collimate toward the jet axis as long as η < 4, leading to the formation of a shocked boundary layer. Assuming that pressure-matching across the shock front determines the shape of the shock, we study the resulting structure of the jet in two ways: first by assuming that the pressure remains constant across the shocked boundary layer and looking for solutions to the shock jump equations, and then by constructing self-similar boundary-layer solutions that allow for a pressure gradient across the shocked layer. We demonstrate that the constant-pressure solutions can be characterized by four initial parameters that determine the jet shape and whether the shock closes to the axis. We show that self-similar solutions for the boundary layer can be constructed that exhibit a monotonic decrease in pressure across the boundary layer from the contact discontinuity to the shock front, and that the addition of this pressure gradient in our initial model generally causes the shock front to move outwards, creating a thinner boundary layer and decreasing the tendency of the shock to close. We discuss trends based on the value of the pressure power-law index η.
Entanglement Entropy of Systems with Spontaneously Broken Continuous Symmetry

We study entanglement properties of systems with spontaneously broken continuous symmetry. We find that in addition to the expected area law behavior, the entanglement entropy contains a subleading contribution which diverges logarithmically with the subsystem size in agreement with the Monte Carlo simulations of A. Kallin et. al. ( (2011)). The coefficient of the logarithm is a universal number given simply by $N_G (d-1)/2$, where $N_G$ is the number of Goldstone modes and $d$ is the spatial dimension. This term is present even when the subsystem boundary is straight and contains no corners, and its origin lies in the interplay of Goldstone modes and restoration of symmetry in a finite volume. We also compute the "low-energy" part of the entanglement spectrum and show that it has the same characteristic "tower of states" form as the physical low-energy spectrum obtained when a system with spontaneously broken continuous symmetry is placed in a finite volume.
Instantons, Twistors, and Emergent Gravity

Motivated by potential applications to holography on space-times of positive curvature, and by the successful twistor description of scattering amplitudes, we propose a new dual matrix formulation of N = 4 gauge theory on S 4 . The matrix model is defined by taking the low energy limit of a holomorphic Chern-Simons theory on CP 3|4 , in the presence of a large instanton flux. The theory comes with a choice of S 4 radius l and a parameter N controlling the overall size of the matrices. The flat space variant of the 4D effective theory arises by taking the large N scaling limit of the matrix model, with l 2 ∼ l 2 /N held fixed. Its massless spectrum contains both spin one and spin two excitations, which we identify with gluons and gravitons. As shown in the companion paper , the matrix model correlation functions of both these excitations correctly reproduce the corresponding MHV scattering amplitudes. We present evidence that the scaling limit defines a gravitational theory with a finite Planck length. In particular we find that in the lpl → 0 limit, the matrix model makes contact with the CSW rules for amplitudes of pure gauge theory, which are uncontaminated by conformal supergravity. We also propose a UV completion for the system by embedding the matrix model in the physical superstring.
Dynamics of competing ideas in complex social systems

Individuals accepting an idea may intentionally or unintentionally impose influences in a certain neighborhood area, making it less likely or even impossible for other individuals within the area to accept competing ideas. Depending on whether such influences strictly prohibit neighborhood individuals from accepting other ideas or not, we classify them into exclusive and non-exclusive influences, respectively. Our study reveals, for the first time, the rich and complex dynamics of two competing ideas with neighborhood influences in scale-free social networks: depending on whether they have exclusive or non-exclusive influences, the final state varies from multiple co-existence to founder control to exclusion, with different sizes of population accepting each of the ideas, respectively. Such results provide helpful insights for better understanding of the spread (and the control of the spread) of ideas in human society.
Multi-GeV neutrino emission from magnetized gamma-ray bursts

We investigate the expected neutrino emissivity from nuclear collisions in magnetically dominated collisional models of gamma-ray bursts, motivated by recent observational and theoretical developments. The results indicate that significant multi-GeV neutrino fluxes are expected for model parameter values which are typical of electromagnetically detected bursts. We show that for detecting at least one muon event in Icecube and its Deep Core sub-array, a single burst must be near the high end of the luminosity function and at a redshift $z\lesssim 0.2$. We also calculate the luminosity and distance ranges that can generate $0.01-1$ muon events per GRB in the same detectors, which may be of interest if simultaneously detected electromagnetically, or if measured with future extensions of Icecube or other neutrino detectors with larger effective volume and better sensitivity.
Arithmetic of Potts model hypersurfaces

We consider Potts model hypersurfaces defined by the multivariate Tutte polynomial of graphs (Potts model partition function). We focus on the behavior of the number of points over finite fields for these hypersurfaces, in comparison with the graph hypersurfaces of perturbative quantum field theory defined by the Kirchhoff graph polynomial. We give a very simple example of the failure of the "fibration condition" in the dependence of the Grothendieck class on the number of spin states and of the polynomial countability condition for these Potts model hypersurfaces. We then show that a period computation, formally similar to the parametric Feynman integrals of quantum field theory, arises by considering certain thermodynamic averages. One can show that these evaluate to combinations of multiple zeta values for Potts models on polygon polymer chains, while silicate tetrahedral chains provide a candidate for a possible occurrence of non-mixed Tate periods.
Strong contraction of the representations of the three-dimensional Lie algebras

For any İnönü–Wigner contraction of a three-dimensional Lie algebra we construct the corresponding contractions of representations. Our method is quite canonical in the sense that in all cases we deal with realizations of the representations on some spaces of functions; we contract the differential operators on those spaces along with the representation spaces themselves by taking certain pointwise limit of functions. We call such contractions strong contractions. We show that this pointwise limit gives rise to a direct limit space. Many of these contractions are new and in other examples we give a different proof.
Strange-particle production via the weak interaction

The differential cross sections for the neutrino-induced weak charged current production of strange particles in the threshold energy region are presented. The general representation of the weak hadronic current is newly developed in terms of eighteen unknown invariant amplitudes to parametrize the hadron vertex. The Born-term approximation is used for the numerical calculations in the framework of the Cabibbo theory and SU(3) symmetry. For unpolarized octet baryons four processes are investigated, whereas in the case of polarized baryons only one process is chosen to study the sensitivity of the differential cross section to the various polarizations of the initial-state nucleon and the final-state hyperon.
Indication for the disappearance of reactor electron antineutrinos in the Double Chooz experiment

The Double Chooz Experiment presents an indication of reactor electron antineutrino disappearance consistent with neutrino oscillations. A ratio of 0.944 $\pm$ 0.016 (stat) $\pm$ 0.040 (syst) observed to predicted events was obtained in 101 days of running at the Chooz Nuclear Power Plant in France, with two 4.25 GW$_{th}$ reactors. The results were obtained from a single 10 m$^3$ fiducial volume detector located 1050 m from the two reactor cores. The reactor antineutrino flux prediction used the Bugey4 measurement as an anchor point. The deficit can be interpreted as an indication of a non-zero value of the still unmeasured neutrino mixing parameter \sang. Analyzing both the rate of the prompt positrons and their energy spectrum we find \sang = 0.086 $\pm$ 0.041 (stat) $\pm$ 0.030 (syst), or, at 90% CL, 0.015 $<$ \sang $\ <$ 0.16.
Influence of frame-dragging on magnetic null points near rotating black holes

Understanding the mechanisms of particle acceleration from the vicinity of black holes poses a challenge. Electromagnetic effects are thought to be a prime suspect, but details still need an explanation. To this end, we study a three-dimensional structure of oblique magnetic fields near a rotating black hole in vacuum. It has been proposed that such a setup can lead to efficient acceleration when plasma is injected near a magnetic null point. We focus our attention especially on the magnetic field in the immediate neighborhood of the magnetic null point, which was previously shown to occur in the equatorial plane. By employing the line integral convolution method, we visualize the magnetic field lines and explore the electric lines rising out of the equatorial plane. We show the magnetic field structure near the boundary of ergosphere, depending on the spin of the black hole. Electric field develops a non-vanishing component passing through the magnetic null point and ensuring efficient acceleration of charged particles from this particular location near the horizon. We also examine the effect of translatory boost on the field lines. Similarly to the frame-dragging by rotation, the linear motion carries field lines along with the black hole. The position of the magnetic null point recedes from the black hole horizon as the spin parameter increases. For the extreme value of a = 1, the null point can occur outside the ergosphere.
Who is the Lord of the Rings: Majorana, Dirac or Lifshitz? The Spin-Orbit-Zeeman Saga in Ultra-cold Fermions

We discuss the emergence of rings of zero-energy excitations in momentum space for superfluid phases of ultra-cold fermions when spin-orbit, Zeeman fields and interactions are varied. We show that phases containing rings of nodes possess non-trivial topological invariants, and that phase transitions between distinct topological phases belong to the Lifshitz class. Upon crossing phase boundaries, existing massless Dirac fermions in the gapless phase anihilate to produce bulk zeromode Majorana fermions at phase boundaries and then become massive Dirac fermions in the gapped phase. We characterize these tunable topological phase transitions via several spectroscopic properties, including excitation spectrum, spectral function and momentum distribution. Since the emergence or disappearance of rings leads to topological transitions in momentum space, we conclude that Lifshitz is the lord of the rings.
Gossip on Weighted Networks

We investigate how suitable a weighted network is for gossip spreading. The proposed model is based on the gossip spreading model introduced by Lind et.al. on unweighted networks. Weight represents "friendship." Potential spreader prefers not to spread if the victim of gossip is a "close friend". Gossip spreading is related to the triangles and cascades of triangles. It gives more insight about the structure of a network. 
We analyze gossip spreading on real weighted networks of human interactions. 6 co-occurrence and 7 social pattern networks are investigated. Gossip propagation is found to be a good parameter to distinguish co-occurrence and social pattern networks. As a comparison some miscellaneous networks and computer generated networks based on ER, BA, WS models are also investigated. They are found to be quite different than the human interaction networks.
The First Year IceCube-DeepCore Results

The IceCube Neutrino Observatory includes a tightly spaced inner array in the deepest ice, called DeepCore, which gives access to low-energy neutrinos with a sizable surrounding cosmic ray muon veto. Designed to be sensitive to neutrinos at energies as low as 10 GeV, DeepCore will be used to study diverse physics topics with neutrino signatures, such as dark matter annihilations and atmospheric neutrino oscillations. The first year of DeepCore physics data-taking has been completed, and the first observation of atmospheric neutrino-induced cascades with IceCube and DeepCore are presented.
Black holes, quantum information, and unitary evolution

The unitary crisis for black holes indicates an apparent need to modify local quantum field theory. This paper explores the idea that quantum mechanics and in particular unitarity are fundamental principles, but at the price of familiar locality. Thus, one should seek to parameterize unitary evolution, extending the field theory description of black holes, such that their quantum information is transferred to the external state. This discussion is set in a broader framework of unitary evolution acting on Hilbert spaces comprising subsystems. Here, various constraints can be placed on the dynamics, based on quantum information-theoretic and other general physical considerations, and one can seek to describe dynamics with "minimal" departure from field theory. While usual spacetime locality may not be a precise concept in quantum gravity, approximate locality seems an important ingredient in physics. In such a Hilbert space approach an apparently "coarser" form of localization can be described in terms of tensor decompositions of the Hilbert space of the complete system. This suggests a general framework in which to seek a consistent description of quantum gravity, and approximate emergence of spacetime. Other possible aspects of such a framework -- in particular symmetries -- are briefly discussed.
Ontologies and tag-statistics

Due to the increasing popularity of collaborative tagging systems, the research on tagged networks, hypergraphs, ontologies, folksonomies and other related concepts is becoming an important interdisciplinary area with great potential and relevance for practical applications. In most collaborative tagging systems the tagging by the users is completely ‘flat’, while in some cases they are allowed to define a shallow hierarchy for their own tags. However, usually no overall hierarchical organization of the tags is given, and one of the interesting challenges of this area is to provide an algorithm generating the ontology of the tags from the available data. In contrast, there are also other types of tagged networks available for research, where the tags are already organized into a directed acyclic graph (DAG), encapsulating the ‘is a sub-category of’ type of hierarchy between each other. In this paper, we study how this DAG affects the statistical distribution of tags on the nodes marked by the tags in various real networks. The motivation for this research was the fact that understanding the tagging based on a known hierarchy can help in revealing the hidden hierarchy of tags in collaborative tagging systems. We analyse the relation between the tag-frequency and the position of the tag in the DAG in two large sub-networks of the English Wikipedia and a protein–protein interaction network. We also study the tag co-occurrence statistics by introducing a two-dimensional (2D) tag-distance distribution preserving both the difference in the levels and the absolute distance in the DAG for the co-occurring pairs of tags. Our most interesting finding is that the local relevance of tags in the DAG (i.e. their rank or significance as characterized by, e.g., the length of the branches starting from them) is much more important than their global distance from the root. Furthermore, we also introduce a simple tagging model based on random walks on the DAG, capable of reproducing the main statistical features of tag co-occurrence. This model has high potential for further practical applications, e.g., it can provide the starting point for a benchmark system in ontology retrieval or it may help pinpoint unusual correlations in the co-occurrence of tags.
WorldWide Telescope in Research and Education

The WorldWide Telescope computer program, released to researchers and the public as a free resource in 2008 by Microsoft Research, has changed the way the ever-growing Universe of online astronomical data is viewed and understood. The WWT program can be thought of as a scriptable, interactive, richly visual browser of the multi-wavelength Sky as we see it from Earth, and of the Universe as we would travel within it. In its web API format, WWT is being used as a service to display professional research data. In its desktop format, WWT works in concert (thanks to SAMP and other IVOA standards) with more traditional research applications such as ds9, Aladin and TOPCAT. The WWT Ambassadors Program (founded in 2009) recruits and trains astrophysically-literate volunteers (including retirees) who use WWT as a teaching tool in online, classroom, and informal educational settings. Early quantitative studies of WWTA indicate that student experiences with WWT enhance science learning dramatically. Thanks to the wealth of data it can access, and the growing number of services to which it connects, WWT is now a key linking technology in the Seamless Astronomy environment we seek to offer researchers, teachers, and students alike.
Sampling properties of directed networks

For many real-world networks only a small "sampled" version of the original network may be investigated; those results are then used to draw conclusions about the actual system. Variants of breadth-first search (BFS) sampling, which are based on epidemic processes, are widely used. Although it is well established that BFS sampling fails, in most cases, to capture the IN component(s) of directed networks, a description of the effects of BFS sampling on other topological properties is all but absent from the literature. To systematically study the effects of sampling biases on directed networks, we compare BFS sampling to random sampling on complete large-scale directed networks. We present new results and a thorough analysis of the topological properties of seven complete directed networks (prior to sampling), including three versions of Wikipedia, three different sources of sampled World Wide Web data, and an Internet-based social network. We detail the differences that sampling method and coverage can make to the structural properties of sampled versions of these seven networks. Most notably, we find that sampling method and coverage affect both the bow-tie structure and the number and structure of strongly connected components in sampled networks. In addition, at a low sampling coverage (i.e., less than 40%), the values of average degree, variance of out-degree, degree autocorrelation, and link reciprocity are overestimated by 30% or more in BFS-sampled networks and only attain values within 10% of the corresponding values in the complete networks when sampling coverage is in excess of 65%. These results may cause us to rethink what we know about the structure, function, and evolution of real-world directed networks.
Primordial power spectrum versus extension parameters beyond the standard model

We reconstruct the shape of the primordial power spectrum of curvature perturbations in extended cosmological models, including addition of massive neutrinos, extra relativistic species, or varying primordial helium abundance, from the latest cosmic microwave background data from the Wilkinson Microwave Anisotropy Probe, the Atacama Cosmology Telescope, and the South Pole Telescope. We find that a scale-invariant primordial spectrum is disfavored by the data at 95% confidence level even in the presence of massive neutrinos, however it can lie within the 95% confidence region if the effective number of relativistic species or the primordial helium abundance is allowed to vary freely. The constraints on the extension parameters from WMAP7 + ACT + H-0 + BAO are the total mass of neutrinos Sigma m(p) < 0.48 eV (95% C.L.), the effective number of relativistic species N-eff 4.50 +/- 0.81, and the primordial helium abundance Y-p 0.303 +/- 0.075. The constraints from WMAP7 + SPT + H-0 + BAO are Sigma m(p) < 0.45 eV (95% C.L.), N-eff 3.86 +/- 0.63, and Y-p 0.277 +/- 0.050.