pinecone/core-2020-05-10-deduplication huggingface dataset:
Sequences of elliptical distributions and mixtures of normal distributions.

Two conditions are shown under which elliptical distributions are scale mixtures of normal distributions with respect to probability distributions. The issue of finding the mixing distribution function is also considered. As a unified theoretical framework, it is also shown that any scale mixture of normal distributions is always a term of a sequence of elliptical distributions, increasing in dimension, and that all the terms of this sequence are also scale mixtures of normal distributions sharing the same mixing distribution function. Some examples are shown as applications of these concepts, showing the way of finding the mixing distribution function
MAGIC observations and multiwavelength properties of the quasar 3C 279 in 2007 and 2009\ud

Context. 3C 279, the first quasar discovered to emit VHE gamma-rays by the MAGIC telescope in 2006, was reobserved by MAGIC in January 2007 during a major optical flare and from December 2008 to April 2009 following an alert from the Fermi space telescope on an exceptionally high gamma-ray state. Aims. The January 2007 observations resulted in a detection on January 16 with significance 5.4 sigma, corresponding to a F (>150 GeV) (3.8 +/- 0.8) x 10(-11) ph cm(-2) s(-1) while the overall data sample does not show significant signal. The December 2008-April 2009 observations did not detect the source. We study the multiwavelength behaviour of the source at the epochs of MAGIC observations, collecting quasi-simultaneous data at optical and X-ray frequencies and for 2009 also gamma-ray data from Fermi. Methods. We study the light curves and spectral energy distribution of the source. The spectral energy distributions of three observing epochs (including the February 2006, which has been previously published) are modelled with one-zone inverse Compton models and the emission on January 16, 2007 also with two zone model and with a lepto-hadronic model. Results. We find that the VHE gamma-ray emission detected in 2006 and 2007 challenges standard one-zone model, based on relativistic electrons in a jet scattering broad line region photons, while the other studied models fit the observed spectral energy distribution more satisfactorily.\u
Massive protostars as gamma-ray sources

Massive protostars have associated bipolar outflows with velocities of
hundreds of km s$^{-1}$. Such outflows can produce strong shocks when interact
with the ambient medium leading to regions of non-thermal radio emission. We
aim at exploring under which conditions relativistic particles are accelerated
at the terminal shocks of the protostellar jets and can produce significant
gamma-ray emission. We estimate the conditions necessary for particle
acceleration up to very high energies and gamma-ray production in the
non-thermal hot spots of jets associated with massive protostars embedded in
dense molecular clouds. We show that relativistic Bremsstrahlung and
proton-proton collisions can make molecular clouds with massive young stellar
objects detectable by the {\it Fermi}{} satellite at MeV-GeV energies and by
Cherenkov telescope arrays in the GeV-TeV range. Gamma-ray astronomy can be
used to probe the physical conditions in star forming regions and particle
acceleration processes in the complex environment of massive molecular clouds.Comment: 10 pages, 5 figures, 2 tables, accepted for publication in Astronomy
  and Astrophysic
Spin-dependent part of $p\bar{p}$ interaction cross section and Nijmegen
  potential

Low energy $p\bar{p}$ interaction is considered taking into account the
polarization of both particles. The corresponding cross sections are calculated
using the Nijmegen nucleon-antinucleon optical potential. Then they are applied
to the analysis of the polarization buildup which is due to the interaction of
stored antiprotons with polarized protons of a hydrogen target. It is shown
that, at realistic parameters of a storage ring and a target, the filtering
mechanism may provide a noticeable polarization in a time comparable with the
beam lifetime.Comment: 10 pages, 3 figure
Note on a reformulation of the strong cosmic censor conjceture based on
  computability

In this letter we provide a reformulation of the strong cosmic censor
conjecture taking into account recent results on Malament--Hogarth space-times.
We claim that the strong version of the cosmic censor conjecture can be
formulated by postulating that a physically relevant space-time is either
globally hyperbolic or possesses the Malament--Hogarth property. But it is
known that a Malament--Hogarth space-time in principle is capable for
performing non-Turing computations such as checking consistency of ZFC set
theory. In this way we get an intimate conjectured link between the cosmic
censorship scenario and computability theory.Comment: LaTeX, 9 pages, 1 eps-figure; minor typos corrected and journal
  reference adde
WASP-54b, WASP-56b and WASP-57b: Three new sub-Jupiter mass planets from
  SuperWASP

We present three newly discovered sub-Jupiter mass planets from the SuperWASP
survey: WASP-54b is a heavily bloated planet of mass 0.636$^{+0.025}_{-0.024}$
\mj and radius 1.653$^{+0.090}_{-0.083}$ \rj. It orbits a F9 star, evolving off
the main sequence, every 3.69 days. Our MCMC fit of the system yields a
slightly eccentric orbit ($e=0.067^{+0.033}_{-0.025}$) for WASP-54b. We
investigated further the veracity of our detection of the eccentric orbit for
WASP-54b, and we find that it could be real. However, given the brightness of
WASP-54 V=10.42 magnitudes, we encourage observations of a secondary eclipse to
draw robust conclusions on both the orbital eccentricity and the thermal
structure of the planet. WASP-56b and WASP-57b have masses of
0.571$^{+0.034}_{-0.035}$ \mj and $0.672^{+0.049}_{-0.046}$ \mj, respectively;
and radii of $1.092^{+0.035}_{-0.033}$ \rj for WASP-56b and
$0.916^{+0.017}_{-0.014}$ \rj for WASP-57b. They orbit main sequence stars of
spectral type G6 every 4.67 and 2.84 days, respectively. WASP-56b and WASP-57b
show no radius anomaly and a high density possibly implying a large core of
heavy elements; possibly as high as $\sim$50 M$_{\oplus}$ in the case of
WASP-57b. However, the composition of the deep interior of exoplanets remain
still undetermined. Thus, more exoplanet discoveries such as the ones presented
in this paper, are needed to understand and constrain giant planets' physical
properties.Comment: 15pages, 19 figures, Submitted to A&A 8-10-2012 Accepted for
  publication 23-12-201
Universality of the Collins-Soper-Sterman nonperturbative function in
  gauge boson production

We revise the $b_*$ model for the Collins-Soper-Sterman resummed form factor
to improve description of the leading-power contribution at nearly
nonperturbative impact parameters. This revision leads to excellent agreement
of the transverse momentum resummation with the data in a global analysis of
Drell-Yan lepton pair and Z boson production. The nonperturbative contributions
are found to follow universal quasi-linear dependence on the logarithm of the
heavy boson invariant mass, which closely agrees with an estimate from the
infrared renormalon analysis.Comment: published version; 14 pages, 4 figures, additional discussio
Resolving the optical emission lines of Lya blob 'B1' at z=2.38: another
  hidden quasar

We have used the SINFONI near-infrared integral field unit on the VLT to
resolve the optical emission line structure of one of the brightest (L~1e44
erg/s) and nearest (z=2.38) of all Lya blobs (LABs). The target, known in the
literature as object 'B1' (Francis et al. 1996), lies at a redshift where the
main optical emission lines are accessible in the observed near-infrared. We
detect luminous [OIII]4959,5007A and Ha emission with a spatial extent of at
least 32x40 kpc (4"x5"). The dominant optical emission line component shows
relatively broad lines (600-800 km/s, FWHM) and line ratios consistent with
AGN-photoionization. The new evidence for AGN photoionization, combined with
previously detected CIV and luminous, warm infrared emission, suggest that B1
is the site of a hidden quasar. This is confirmed by the fact that [OII] is
relatively weak compared to [OIII] (extinction-corrected [OIII]/[OII] of about
3.8), which is indicative of a high, Seyfert-like ionization parameter. From
the [OIII] luminosity we infer a bolometric AGN luminosity of ~3e46 erg/s, and
further conclude that the obscured AGN may be Compton-thick given existing
X-ray limits. The large line widths observed are consistent with clouds moving
within the narrow line region of a luminous QSO. The AGN scenario is capable of
producing sufficient ionizing photons to power the Lya, even in the presence of
dust. By performing a census of similar objects in the literature, we find that
virtually all luminous LABs harbor obscured quasars. Based on simple duty-cycle
arguments, we conclude that AGN are the main drivers of the Lya in LABs rather
than the gravitational heating and subsequent cooling suggested by cold stream
models. We also conclude that the empirical relation between LABs and overdense
environments at high redshift must be due to a more fundamental correlation
between AGN (or massive galaxies) and environment.Comment: ApJ, Accepted (12 pages, 6 figures, 2 tables
Numerical simulations of granular dynamics. I. Hard-sphere discrete
  element method and tests

We present a new particle-based (discrete element) numerical method for the
simulation of granular dynamics, with application to motions of particles on
small solar system body and planetary surfaces. The method employs the parallel
N-body tree code pkdgrav to search for collisions and compute particle
trajectories. Collisions are treated as instantaneous point-contact events
between rigid spheres. Particle confinement is achieved by combining arbitrary
combinations of four provided wall primitives, namely infinite plane, finite
disk, infinite cylinder, and finite cylinder, and degenerate cases of these.
Various wall movements, including translation, oscillation, and rotation, are
supported. We provide full derivations of collision prediction and resolution
equations for all geometries and motions. Several tests of the method are
described, including a model granular "atmosphere" that achieves correct energy
equipartition, and a series of tumbler simulations that show the expected
transition from tumbling to centrifuging as a function of rotation rate.Comment: 54 manuscript pages, 8 figures including 4 in colour (online version
  only
Systemic Losses Due to Counter Party Risk in a Stylized Banking System

We report a study of a stylized banking cascade model investigating systemic
risk caused by counter party failure using liabilities and assets to define
banks' balance sheet. In our stylized system, banks can be in two states:
normally operating or distressed and the state of a bank changes from normally
operating to distressed whenever its liabilities are larger than the banks'
assets. The banks are connected through an interbank lending network and,
whenever a bank is distressed, its creditor cannot expect the loan from the
distressed bank to be repaid, potentially becoming distressed themselves. We
solve the problem analytically for a homogeneous system and test the robustness
and generality of the results with simulations of more complex systems. We
investigate the parameter space and the corresponding distribution of operating
banks mapping the conditions under which the whole system is stable or
unstable. This allows us to determine how financial stability of a banking
system is influenced by regulatory decisions, such as leverage; we discuss the
effect of central bank actions, such as quantitative easing and we determine
the cost of rescuing a distressed banking system using re-capitalisation.
Finally, we estimate the stability of the UK and US banking systems in the
years 2007 and 2012 showing that both banking systems were more unstable in
2007 and connectedness on the interbank market partly caused the banking
crisis.Comment: 31 pages 13 figure
SUSY properties of warped AdS$_3$

We examine supersymmetric properties of null-warped AdS$_3$, or alternatively
Schrodinger geometries, dual to putative warped CFTs in two dimensions. We
classify super Schrodinger subalgebras of the superalgebra psu(1, 1$|$2)
$\oplus$ psu(1, 1$|$2), corresponding to the superconformal algebra of the
AdS$_3 \times$ S$^3$ geometry. We comment on geometric realisations and provide
a string theory description with enhanced supersymmetry in terms of
intersecting D3-branes. For type IIB supergravity solutions based on T$^{1,1}$,
we consider the relationship between five-dimensional Schrodinger solutions and
their three-dimensional null-warped counterparts, corresponding to R symmetry
twists. Finally, we study a family of null-warped AdS$_3$ solutions in a
setting where there is an ambiguity over the R symmetry and confirm that, for
examples admitting a Kaluza-Klein (KK) reduction to three dimensions, the
minimisation of a real superpotential of the three-dimensional gauged
supergravity captures the central charge and R symmetry.Comment: 44 pages, v2 reference added, typos corrected, acknowledgements adde
Axial Dark Matter: the case for an invisible Z'

We consider the possibility that fermionic dark matter (DM) interacts with
the Standard Model fermions through an axial Z' boson. As long as Z' decays
predominantly into dark matter, the relevant LHC bounds are rather loose.
Direct dark matter detection does not significantly constrain this scenario
either, since dark matter scattering on nuclei is spin--dependent. As a result,
for a range of the Z' mass and couplings, the DM annihilation cross section is
large enough to be consistent with thermal history of the Universe. In this
framework, the thermal WIMP paradigm, which currently finds itself under
pressure, is perfectly viable.Comment: 10 pages, 2 figure
Point defects and p-type conductivity in Zn/1-x/Mn/x/GeAs/2/

Positron annihilation spectroscopy is used to study point defects in
Zn/1-x/Mn/x/GeAs/2/ crystals with low Mn content 0 < x < 0.042 with disordered
zincblende and chalcopyrite structure. The role of negatively charged vacancies
and non-open-volume defects is discussed with respect to the high p-type
conductivity with carrier concentration 1E19 < n < 1E21 cm^-3 in our samples.
Neutral As vacancies, together with negatively charged Zn vacancies and
non-open-volume defects with concentrations around 1E16-1E18 cm^-3, increasing
with the amount of Mn in the alloy, are observed. The observed concentrations
of defects are not sufficient to be responsible for the strong p-type
conductivity of our crystals. Therefore, we suggest that other types of
defects, such as extended defects, have a strong influence on the conductivity
of Zn1-xMnxGeAs2 crystals.Comment: 8 pages, 3 figure
Localization in Supergravity and Quantum $AdS_4/CFT_3$ Holography

We compute the quantum gravity partition function of M-theory on $AdS_4
\times X_7 $ by using localization techniques in four-dimensional gauged
supergravity obtained by a consistent truncation on the Sasaki-Einstein
manifold $X_{7}$. The supergravity path integral reduces to a finite
dimensional integral over two collective coordinates that parametrize the
localizing instanton solutions. The renormalized action of the off-shell
instanton solutions depends linearly and holomorphically on the "square root"
prepotential evaluated at the center of $AdS_{4}$. The partition function
resembles the Laplace transform of the wave function of a topological string
and with an assumption about the measure for the localization integral yields
an Airy function in precise agreement with the computation from the boundary
ABJM theory on a 3-sphere. Our bulk quantum gravity computation is
nonperturbatively exact in four-dimensional Planck length but ignores
corrections due to brane-instantons.Comment: 32 pages; v2: minor changes, JHEP versio
Holographic Entropy and Calabi's Diastasis

The entanglement entropy for interfaces and junctions of two-dimensional CFTs
is evaluated on holographically dual half-BPS solutions to six-dimensional Type
4b supergravity with m anti-symmetric tensor supermultiplets. It is shown that
the moduli space for an N-junction solution projects to N points in the Kaehler
manifold SO(2,m)/( SO(2) x SO(m)). For N=2 the interface entropy is expressed
in terms of the central charge and Calabi's diastasis function on
SO(2,m)/(SO(2) x SO(m)), thereby lending support from holography to a proposal
of Bachas, Brunner, Douglas, and Rastelli. For N=3, the entanglement entropy
for a 3-junction decomposes into a sum of diastasis functions between pairs,
weighed by combinations of the three central charges, provided the flux charges
are all parallel to one another or, more generally, provided the space of flux
charges is orthogonal to the space of unattracted scalars. Under similar
assumptions for N>3, the entanglement entropy for the N-junction solves a
variational problem whose data consist of the N central charges, and the
diastasis function evaluated between pairs of N asymptotic AdS_3 x S^3 regions.Comment: 34 pages, 3 figure
Clustering and Signalling of Cooperative Receptors: a Unified Model

We present a model of cooperativity between transmembrane receptors. Two responses to ligand binding, receptor signalling and the enhancement of clustering, or oligomerization, are unified in the same framework. The model is based on a conformation-dependent interaction between neighboring receptors. In order to decrease the total energy of the system, neighboring receptors tend to have a same conformational state, while receptors with the same conformational state tend to cluster together. In the presence of noise, there is a probability distribution of various configurations of the system. This situation is treated using analytical and numerical methods of statistical mechanics. Signalling sensitivity is enhanced by an appropriate choice of coupling-noise-ratio. There is a range of the threshold value of receptor conformational change for which clustering is enhanced by ligand binding
A study of strange particle production in $\nu_\mu$ charged current interactions in the NOMAD experiment

A study of strange particle production in $\nu_\mu$ charged current interactions has been performed using the data from the NOMAD experiment. Yields of neutral strange particles ($K^0_s, \Lambda, \bar{\Lambda}$) have been measured. Mean multiplicities are reported as a function of the event kinematic variables $E_\nu$, $W^2$ and $Q^2$ as well as of the variables describing particle behaviour within a hadronic jet: $x_F$, $z$ and $p_T^2$. Decays of resonances and heavy hyperons with identified $K^0_s$ and $\Lambda$ in the final state have been analyzed. Clear signals corresponding to $\rm {K^\star}^\pm$ $\rm {\Sigma^\star}^\pm$, $\rm \Xi^-$ and $\rm \Sigma^0$ have been observed.A study of strange particle production in muon neutrino charged current interactions has been performed using the data from the NOMAD experiment. Yields of neutral strange particles K0s, Lambda, AntiLambda have been measured. Mean multiplicities are reported as a function of the event kinematic variables Enu, W2 and Q2 as well as of the variables describing particle behaviour within a hadronic jet: xF, z and pT2. Decays of resonances and heavy hyperons with identified K0s and Lambda in the final state have been analyzed. Clear signals corresponding to K*+-, Sigma*+-, Xi- and Sigma0 have been observed.A study of strange particle production in ν μ charged current interactions has been performed using the data from the NOMAD experiment. Yields of neutral strange particles ( K 0 s ,Λ, Λ ̄ ) have been measured. Mean multiplicities are reported as a function of the event kinematic variables E ν , W 2 and Q 2 as well as of the variables describing particle behaviour within a hadronic jet: x F , z and p T 2 . Decays of resonances and heavy hyperons with identified K 0 s and Λ in the final state have been analyzed. Clear signals corresponding to K ★± , Σ ★± , Ξ − and Σ 0 have been observed
On f-vectors of Minkowski additions of convex polytopes

The objective of this paper is to present two types of results on Minkowski
sums of convex polytopes. The first is about a special class of polytopes we
call perfectly centered and the combinatorial properties of the Minkowski sum
with their own dual. In particular, we have a characterization of face lattice
of the sum in terms of the face lattice of a given perfectly centered polytope.
Exact face counting formulas are then obtained for perfectly centered simplices
and hypercubes. The second type of results concerns tight upper bounds for the
f-vectors of Minkowski sums of several polytopes.Comment: 13 pages, submitted to Discrete & Computational Geometr
Anisotropic fluctuations in turbulent sheared flows

An experimental analysis of small-scales anisotropic turbulent fluctuations
has been performed in two different flows. We analyzed anisotropic properties
of an homogeneous shear flows and of a turbulent boundary layer by means of two
cross-wire probes to obtain multi-point multi-component measurements. Data are
analyzed at changing inter-probe separation without the use of Taylor
hypothesis. The results are consistent with the ``exponent-only'' scenario for
universality, i.e. all experimental data can be fit by fixing the same set of
anisotropic scaling exponents at changing only prefactors, for different shear
intensities and boundary conditions.Comment: 11 pages, 8 figure
The mass function of dark matter haloes.

We combine data from a number of N-body simulations to predict the abundance of dark haloes in cold dark matter (CDM) universes over more than four orders of magnitude in mass. A comparison of different simulations suggests that the dominant uncertainty in our results is systematic and is smaller than 10–30 per cent at all masses, depending on the halo definition used. In particular, our 'Hubble volume' simulations of τCDM and ΛCDM cosmologies allow the abundance of massive clusters to be predicted with uncertainties well below those expected in all currently planned observational surveys. We show that for a range of CDM cosmologies and for a suitable halo definition, the simulated mass function is almost independent of epoch, of cosmological parameters and of the initial power spectrum when expressed in appropriate variables. This universality is of exactly the kind predicted by the familiar Press–Schechter model, although this model predicts a mass function shape that differs from our numerical results, overestimating the abundance of 'typical' haloes and underestimating that of massive systems
A simulated tauCDM cosmology cluster catalogue: the NFW profile and the temperature-mass scaling relations

We have extracted over 400 clusters, covering more than two decades in mass, from three simulations of the tauCDM cosmology. This represents the largest uniform catalogue of simulated clusters ever produced. The clusters exhibit a wide variety of density profiles. Only a minority are well-fitted in their outer regions by the widely used density profile of Navarro, Frenk & White (NFW), which is applicable to relaxed haloes. Others have steeper outer density profiles, show sharp breaks in their density profiles, or have significant substructure. If we force a fit to the NFW profile, then the best-fitting concentrations decline with increasing mass, but this is driven primarily by an increase in substructure as one moves to higher masses. The temperature-mass relations for properties measured within a sphere enclosing a fixed overdensity all follow the self-similar form, T~M2/3 however, the normalization is lower than the value inferred for observed clusters. The temperature-mass relations for properties measured within a fixed physical radius are significantly steeper then this. Both can be accurately predicted using the NFW model