pinecone/core-2020-05-10-deduplication huggingface dataset:
Properties of the symplectic structure of General Relativity for
  spatially bounded spacetime regions

We continue a previous analysis of the covariant Hamiltonian symplectic
structure of General Relativity for spatially bounded regions of spacetime. To
allow for near complete generality, the Hamiltonian is formulated using any
fixed hypersurface, with a boundary given by a closed spacelike 2-surface. A
main result is that we obtain Hamiltonians associated to Dirichlet and Neumann
boundary conditions on the gravitational field coupled to matter sources, in
particular a Klein-Gordon field, an electromagnetic field, and a set of
Yang-Mills-Higgs fields. The Hamiltonians are given by a covariant form of the
Arnowitt-Deser-Misner Hamiltonian modified by a surface integral term that
depends on the particular boundary conditions. The general form of this surface
integral involves an underlying ``energy-momentum'' vector in the spacetime
tangent space at the spatial boundary 2-surface. We give examples of the
resulting Dirichlet and Neumann vectors for topologically spherical 2-surfaces
in Minkowski spacetime, spherically symmetric spacetimes, and stationary
axisymmetric spacetimes. Moreover, we show the relation between these vectors
and the ADM energy-momentum vector for a 2-surface taken in a limit to be
spatial infinity in asymptotically flat spacetimes. We also discuss the
geometrical properties of the Dirichlet and Neumann vectors and obtain several
striking results relating these vectors to the mean curvature and normal
curvature connection of the 2-surface. Most significantly, the part of the
Dirichlet vector normal to the 2-surface depends only the spacetime metric at
this surface and thereby defines a geometrical normal vector field on the
2-surface. Properties and examples of this normal vector are discussed.Comment: 46 pages; minor errata corrected in Eqs. (3.15), (3.24), (4.37) and
  in discussion of examples in sections IV B,
Observation of the strange sea in the proton via inclusive Phi-meson
  production in neutral current deep inelastic scattering at HERA

Inclusive phi-meson production in neutral current deep inelastic e+p
scattering has been measured with the ZEUS detector at HERA using an integrated
luminosity of 45 pb^{-1}. The phi mesons were studied in the range 10<Q2<100
GeV2, where Q2 is the virtuality of the exchanged photon, and in restricted
kinematic regions in the transverse momentum, p_T, pseudorapidity, eta, and the
scaled momentum in the Breit frame, x_p. Monte Carlo models with the
strangeness-suppression factor as determined by analyses of e+e- annihilation
events overestimate the cross sections. A smaller value of the
strangeness-suppression factor reduces the predicted cross sections, but fails
to reproduce the shapes of the measured differential cross sections.
High-momentum phi mesons in the current region of the Breit frame give the
first direct evidence for the strange sea in the proton at low x.Comment: 20 pages including 5 figures and 2 table
A General Classification of Three-Neutrino Models and U_e3

A classification of models with three light neutrinos is given. This
classification includes virtually all of the three-neutrino models proposed in
the last few years, of which there are approximately one hundred. The essential
ideas, attractive features, and characteristic problems of the different
classes of model are discussed. The classification is based principally on how
the large \nu_{\mu} - \nu_{\tau} mixing is obtained. A general discussion of
the mixing parameter U_{e3} is then given, showing what values are to be
expected for it in each type of model.Comment: 37 pages, LaTex. Several serious typos correcte
Improved Unitarized Heavy Baryon Chiral Perturbation Theory for $\pi N $
  Scattering

We show how the unitarized description of pion nucleon scattering within
Heavy Baryon Chiral Perturbation Theory can be considerably improved, by a
suitable reordering of the expansion over the nucleon mass. Within this
framework, the $\Delta$ resonance and its associated pole can be recovered from
the chiral parameters obtained from low-energy determinations. In addition, we
can obtain a good description of the six $S$ and $P$ wave phase shifts in terms
of chiral parameters with a natural size and compatible with the Resonance
Saturation Hypothesis.Comment: 10 pages, 3 tables, 2 figure
Some aspects of self-duality and generalised BPS theories

If a scalar field theory in (1+1) dimensions possesses soliton solutions
obeying first order BPS equations, then, in general, it is possible to find an
infinite number of related field theories with BPS solitons which obey closely
related BPS equations. We point out that this fact may be understood as a
simple consequence of an appropriately generalised notion of self-duality. We
show that this self-duality framework enables us to generalize to higher
dimensions the construction of new solitons from already known solutions. By
performing simple field transformations our procedure allows us to relate
solitons with different topological properties. We present several interesting
examples of such solitons in two and three dimensions.Comment: 29 pages, Latex fil
Collider signatures of a light NMSSM pseudoscalar in neutralino decays
  in the light of LHC results

We investigate signatures induced by a very light pseudoscalar Higgs in
neutralino decays in the Next-to-Minimal Supersymmetric Standard Model (NMSSM)
and determine their observability at the LHC. We concentrate on scenarios which
feature two light scalar Higgs bosons (one of them is SM-like with a mass of
125 GeV and a singlet-like lighter one) with a very light (singlet-like)
pseudoscalar Higgs in the mass range 2m_tau < m_a1 < 2m_b. We consider
neutralino-chargino pair production and the subsequent decay X_{2,3}-> X_1 a1,
which leads to topologies involving multi-leptons and missing transverse
energy. We determine a set of selection cuts that can effectively isolate the
signal from backgrounds of the Standard Model or the Minimal Supersymmetric
Standard Model. We also exemplify the procedure with a set of benchmark points,
for which we compute the expected number of events and signal strength for LHC
with 8 TeV center of mass energy. We show that this signal can already be
probed for some points in the NMSSM parameter space.Comment: 29 pages, 10 figures. one new table and one new figure added,
  modification in text. References added. Matches with the published version in
  JHE
Ionization in Atmospheres of Brown Dwarfs and Extrasolar Planets V:
  Alfv\'{e}n Ionization

Observations of continuous radio and sporadic X-ray emission from low-mass
objects suggest they harbour localized plasmas in their atmospheric
environments. For low-mass objects, the degree of thermal ionization is
insufficient to qualify the ionized component as a plasma, posing the question:
what ionization processes can efficiently produce the required plasma that is
the source of the radiation? We propose Alfv\'{e}n ionization as a mechanism
for producing localized pockets of ionized gas in the atmosphere, having
sufficient degrees of ionization ($\geq10^{-7}$) that they constitute plasmas.
We outline the criteria required for Alfv\'{e}n ionization and demonstrate it's
applicability in the atmospheres of low-mass objects such as giant gas planets,
brown dwarfs and M-dwarfs for both solar and sub-solar metallicities. We find
that Alfv\'{e}n ionization is most efficient at mid to low atmospheric
pressures where a seed plasma is easier to magnetize and the pressure gradients
needed to drive the required neutral flows are the smallest. For the model
atmospheres considered, our results show that degrees of ionization of
$10^{-6}-1$ can be obtained as a result of Alfv\'{e}n ionization. Observable
consequences include continuum Bremsstrahlung emission, superimposed with
spectral lines from the plasma ion species (e.g. He, Mg, H$_{2}$ or CO lines).
Forbidden lines are also expected from the metastable population. The presence
of an atmospheric plasma opens the door to a multitude of plasma and chemical
processes not yet considered in current atmospheric models. The occurrence of
Alfv\'{e}n ionization may also be applicable to other astrophysical
environments such as protoplanetary disks.Comment: 53 pages, 18 figures, Accepted to Ap
On the stability of multi-scale models of dynamical symmetry breaking
  from holography

We consider two classes of backgrounds of Type IIB supergravity obtained by
wrapping D5-branes on a two-cycle inside the conifold. The field theory dual
exhibits confinement and, in addition, a region in which the dynamics is
walking, at least in the weak sense that the running of the coupling is
anomalously slow. We introduce quenched matter in the fundamental, modelled by
probe D7-branes which wrap an internal three-dimensional manifold and lie at
the equator of the transverse two-sphere. In the space spanned by the remaining
internal angle and the radial coordinate the branes admit two embeddings. The
first one is U-shaped: the branes merge at some finite value of the radius. The
second one is disconnected and extends along the entire radial direction at
fixed angular separation. We interpret these two configurations as
corresponding to chiral-symmetry breaking and preserving phases, respectively.
We present a simple diagnostic tool to examine the classical stability of the
embedding, based on the concavity/convexity conditions for the relevant
thermodynamic potentials. We use this criterion to show that U-shaped probes
that explore the walking region are unstable, hence providing a dynamical
origin for the tachyonic mode found in the literature. Whenever this occurs,
the disconnected solution becomes favored energetically. We find that in one of
the two classes of backgrounds the U-shaped embedding is always unstable, and
thus never realised dynamically. Consequently, these models cannot be used to
describe chiral-symmetry breaking. In the second category of solutions, our
analysis reveals the presence of a first-order phase transition between
chiral-symmetry broken and restored phases. Interestingly, this is in the same
class that contains a parametrically light scalar in the spectrum of glueballs
of the dual field theory.Comment: 17 pages, 8 figures; v2 minor corrections, results and analysis
  unaffected, references amende
HALOGAS observations of NGC 4414: fountains, interaction, and ram
  pressure

We present deep HI imaging of the nearby spiral galaxy NGC 4414, taken as
part of the Westerbork HALOGAS (Hydrogen Accretion in LOcal GAlaxieS) survey.
The observations show that NGC 4414 can be characterized by a regularly
rotating inner HI disk, and a more disturbed outer disk. Modeling of the
kinematics shows that the outer disk is best described by a U-shaped warp. Deep
optical imaging also reveals the presence of a low surface brightness stellar
shell, indicating a minor interaction with a dwarf galaxy at some stage in the
past. Modeling of the inner disk suggests that about 4 percent of the inner HI
is in the form of extra-planar gas. Because of the the disturbed nature of the
outer disk, this number is difficult to constrain for the galaxy as a whole.
These new, deep observations of NGC 4414 presented here show that even
apparently undisturbed galaxies are interacting with their environment.Comment: Accepted for publication in Astronomy and Astrophysic
Strichartz estimates and moment bounds for the relativistic
  Vlasov-Maxwell system II. Continuation criteria in the 3D case

We consider the $3$-dimensional relativistic Vlasov-Maxwell system with data
without compact support in momentum space. We prove two continuation criteria
for solutions to this system. First, we show that a regular solution can be
continued if the integral of the electromagnetic field along any characteristic
is assumed to be bounded. This can be viewed as a generalization of the
classical result of Glassey-Strauss (1986) to data with non-compact momentum
support. Second, we extend the methods in our companion paper (Part I) to show
that a regular solution can be extended as long as $\|\pel_0^{\th} f
\|_{L^q_xL^1_{\pel}}$ remains bounded for $\th>\frac 2q$, $2<q\leq \infty$.
This improves previous results of Pallard (2005).Comment: 37 pages, submitte
Probing the small-$x$ nuclear gluon distributions with isolated photons
  at forward rapidities in p+Pb collisions at the LHC

Inclusive direct photon production in p+Pb collisions at the LHC is studied
within the NLO perturbative QCD. Our aim is to quantify the dominant $x$
regions probed at different rapidities and to identify the best conditions for
testing the nuclear gluon parton distribution functions (nPDFs) at small $x$. A
comparison to the inclusive pion production reveals that from these two
processes the photons carry more sensitivity to the small-$x$ partons and that
this sensitivity can be further increased by imposing an isolation cut for the
photon events. The details of the isolation criteria, however, seem to make
only a small difference to the studied $x$ sensitivity and have practically no
effect on the expected nuclear modifications. We consider also the yield
asymmetry between forward and backward rapidities which can be used to probe
the nPDFs irrespectively of whether an accurate p+p baseline is available.Comment: 15 pages, 17 figure
Non-oscillatory flux correlation functions for efficient nonadiabatic
  rate theory

There is currently much interest in the development of improved
trajectory-based methods for the simulation of nonadiabatic processes in
complex systems. An important goal for such methods is the accurate calculation
of the rate constant over a wide range of electronic coupling strengths and it
is often the nonadiabatic, weak-coupling limit, which being far from the
Born-Oppenheimer regime, provides the greatest challenge to current methods. We
show that in this limit there is an inherent sign problem impeding further
development which originates from the use of the usual quantum flux correlation
functions, which can be very oscillatory at short times. From linear response
theory, we derive a modified flux correlation function for the calculation of
nonadiabatic reaction rates, which still rigorously gives the correct result in
the long-time limit regardless of electronic coupling strength, but unlike the
usual formalism is not oscillatory in the weak-coupling regime. In particular,
a trajectory simulation of the modified correlation function is naturally
initialized in a region localized about the crossing of the potential energy
surfaces. In the weak-coupling limit, a simple link can be found between the
dynamics initialized from this transition-state region and an generalized
quantum golden-rule transition-state theory, which is equivalent to Marcus
theory in the classical harmonic limit. This new correlation function formalism
thus provides a platform on which a wide variety of dynamical simulation
methods can be built aiding the development of accurate nonadiabatic rate
theories applicable to complex systems.Comment: Submitted to the Journal of Chemical Physics. 16 pages with 5 figure
The host galaxies of X-ray selected Active Galactic Nuclei to z=2.5:
  Structure, star-formation and their relationships from CANDELS and
  Herschel/PACS

We study the relationship between the structure and star-formation rate (SFR)
of X-ray selected low and moderate luminosity active galactic nuclei (AGNs) in
the two Chandra Deep Fields, using Hubble Space Telescope imaging from the
Cosmic Assembly Near Infrared Extragalactic Legacy Survey (CANDELS) and deep
far-infrared maps from the PEP+GOODS-Herschel survey. We derive detailed
distributions of structural parameters and FIR luminosities from carefully
constructed control samples of galaxies, which we then compare to those of the
AGNs. At z~1, AGNs show slightly diskier light profiles than massive inactive
(non-AGN) galaxies, as well as modestly higher levels of gross galaxy
disturbance (as measured by visual signatures of interactions and clumpy
structure). In contrast, at z~2, AGNs show similar levels of galaxy disturbance
as inactive galaxies, but display a red central light enhancement, which may
arise due to a more pronounced bulge in AGN hosts or due to extinguished
nuclear light. We undertake a number of tests of these alternatives, but our
results do not strongly favour one interpretation over the other. The mean SFR
and its distribution among AGNs and inactive galaxies are similar at z>1.5. At
z<1, however, clear and significant enhancements are seen in the SFRs of AGNs
with bulge-dominated light profiles. These trends suggest an evolution in the
relation between nuclear activity and host properties with redshift, towards a
minor role for mergers and interactions at z>1.5.Comment: 25 pages (double-column), 17 Figures, under review at A&
Four-Dimensional Einstein Yang-Mills De Sitter Gravity From Eleven
  Dimensions

We obtain D=4 de Sitter gravity coupled to SU(2) Yang-Mills gauge fields from
an explicit and consistent truncation of D=11 supergravity via Kaluza-Klein
dimensional reduction on a non-compact space. The ``internal'' space is a
smooth hyperbolic 7-space (H^7) written as a foliation of two 3-spheres, on
which the SU(2) Yang-Mills fields reside. The positive cosmological constant is
completely fixed by the SU(2) gauge coupling constant. The explicit reduction
ansatz enables us to lift any of the D=4 solutions to D=11. In particular, we
obtain dS_2 in M-theory, where the nine-dimensional transverse space is an H^7
bundle over S^2. We also obtain a new smooth embedding of dS_3 in D=6
supergravity.Comment: Latex, 10 pages, references adde
Gauge invariant vortex vacuum textures and the gluon condensate

In SU(2) lattice gauge theory, a new self-restricted cooling procedure is developed which removes the SU(2)/Z_2 coset fields from the lattice configurations and thus reveals the the Z_2 vortex vacuum texture. The emerging gauge invariant vortex vacuum structure amounts to the full string tension. The action density of the vortex texture extrapolates to the continuum limit, and, hence, gives rise to a mass dimension four condensate which features in the operator product expansion and which is of pure vortex origin
Functional Integral Construction of the Thirring model: axioms
  verification and massless limit

We construct a QFT for the Thirring model for any value of the mass in a
functional integral approach, by proving that a set of Grassmann integrals
converges, as the cutoffs are removed and for a proper choice of the bare
parameters, to a set of Schwinger functions verifying the Osterwalder-Schrader
axioms. The corresponding Ward Identities have anomalies which are not linear
in the coupling and which violate the anomaly non-renormalization property.
Additional anomalies are present in the closed equation for the interacting
propagator, obtained by combining a Schwinger-Dyson equation with Ward
Identities.Comment: 55 pages, 9 figure
A quantitative investigation into the accumulation of rounding errors in
  the numerical solution of ODEs

We examine numerical rounding errors of some deterministic solvers for
systems of ordinary differential equations (ODEs). We show that the
accumulation of rounding errors results in a solution that is inherently random
and we obtain the theoretical distribution of the trajectory as a function of
time, the step size and the numerical precision of the computer. We consider,
in particular, systems which amplify the effect of the rounding errors so that
over long time periods the solutions exhibit divergent behaviour. By performing
multiple repetitions with different values of the time step size, we observe
numerically the random distributions predicted theoretically. We mainly focus
on the explicit Euler and RK4 methods but also briefly consider more complex
algorithms such as the implicit solvers VODE and RADAU5.Comment: 17 pages, 7 figure
Localized Beampipe Heating due to $e^-$ Capture and Nuclear Excitation
  in Heavy Ion Colliders

At heavy ion colliders, two major sources of beam loss are expected to be
$e^+e^-$ production, where the $e^-$ is bound to one of the nuclei, and
photonuclear excitation and decay via neutron emission. Both processes alter
the ions charged to mass ratio by well defined amounts, creating beams of
particles with altered magnetic rigidity. These beams will deposit their energy
in a localized region of the accelerator, causing localized heating, The size
of the target region depends on the collider optics. For medium and heavy ions,
at design luminosity at the Large Hadron Collider, local heating may be more
than an order of magnitude higher than expected. This could cause magnet
quenches if the local cooling is inadequate. The altered-rigidity beams will
also produce localized radiation damage. The beams could also be extracted and
used for fixed target experiments.Comment: Numerical Error fixed; to appear in NIM. 15 pages, no figure
Children's Understanding Of The Relationship Between Addition and Subtraction

In learning mathematics, children must master fundamental logical relationships, including the inverse relationship between addition and subtraction. At the start of elementary school, children lack generalized understanding of this relationship in the context of exact arithmetic problems: they fail to judge, for example, that 12 + 9 − 9 yields 12. Here, we investigate whether preschool children’s approximate number knowledge nevertheless supports understanding of this relationship. Five-year-old children were more accurate on approximate large-number arithmetic problems that involved an inverse transformation than those that did not, when problems were presented in either non-symbolic or symbolic form. In contrast they showed no advantage for problems involving an inverse transformation when exact arithmetic was involved. Prior to formal schooling, children therefore show generalized understanding of at least one logical principle of arithmetic. The teaching of mathematics may be enhanced by building on this understanding.Psycholog
People management and emerging market multinationals

There is a very extensive body of literature on how multinationals manage their people in different national contexts. However, the bulk of this literature focuses on the case of multinationals from the advanced industrial economies, and to a considerable extent, the United States. Very much less has been written on multinationals with their country of origin being an emerging market, and what there has focuses on a very limited number of preferred cases. The growing importance of emerging economies has lead to an upsurge of strategy research on the topic (Wright, Filatotchev, Hoskisson and Peng, 2005); however, research on HRM has not paid enough attention to Emerging Market Multinational Enterprises (EMNEs). Many EMNEs tend to be smaller in size with considerably lesser resources and international experience than their counterparts from developed markets limiting their ability to transfer management practice across their subsidiaries (Thite, Wilkinson, & Shah, 2012), although there are important exceptions to this rule. This introductory article seeks to contribute to the emerging body of literature in this area, through seeking to encourage fresh insights particularly on the varieties of people management encountered in different national contexts