pinecone/core-2020-05-10-deduplication huggingface dataset:
Characterization of amorphous and crystalline silicon nanoclusters in
  ultra thin silica layers

The nucleation and structure of silicon nanocrystals formed by different
preparation conditions and silicon concentration (28 - 70 area %) have been
studied using Transmission Electron Microscopy (TEM), Energy Filtered TEM
(EFTEM) and Secondary Ion Mass Spectroscopy (SIMS). The nanocrystals were
formed after heat treatment at high temperature of a sputtered 10 nm thick
silicon rich oxide on 3 nm SiO$_2$ layer made by Rapid Thermal Oxidation (RTO)
of silicon. Nanocrystals precipitate when the excess silicon concentration
exceeds 50 area %. Below this percentage amorphous silicon nanoclusters were
found. In-situ heat treatment of the samples in the TEM showed that the
crystallization requires a temperature above 800$^o$C. The nanocrystals
precipitate in a 4 nm band, 5 nm from the Si substrate and 4 nm from the
SiO$_2$ sample surface. The silicon nucleates where the excess Si concentration
is the highest. The top surface has less excess Si due to reaction with oxygen
from the ambient during annealing. The SiO$_2$-RTO layer is more Si rich due to
Si diffusion from the SiO$_2$-Si layer into RTO. Twinning and stacking faults
were found in nanocrystals with 4-10 nm in diameter. These types of defects may
have large effects upon the usability of the material in electronic devices.
Both single and double twin boundaries have been found in the nanocrystals by
high resolution transmission electron microscopy (HRTEM). Image simulations
were carried out in order to obtain more information about the defects and
nanocrystals. The stacking faults are extrinsic and located in the twin
boundaries
Dynamically Induced Spontaneous Symmetry Breaking in 3-3-1 Models

We show that in SU(3)_C X SU(3)_L X U(1)_N (3-3-1) models embedded with a
singlet scalar playing the role of the axion, after imposing scale invariance,
dynamical symmetry breaking of Peccei-Quinn symmetry occurs through the
one-loop effective potential for the singlet field. We, then, analyze the
structure of spontaneous symmetry breaking by studying the new scalar potential
for the model, and verify that electroweak symmetry breaking is tightly
connected to the 3-3-1 breaking by the strong constraints among their vacuum
expectation values. This offers a valuable guide to write down the correct
pattern of symmetry breaking for multi-scalar theories. We also obtained that
the accompanying massive pseudo-scalar, instead of acquiring mass of order of
Peccei-Quinn scale as we would expect, develops a mass at a much lower scale, a
consequence solely of the dynamical breaking.Comment: 12 pages, typos corrected, improved text, conclusions unchange
Modular discretization of the AdS2/CFT1 Holography

We propose a finite discretization for the black hole geometry and dynamics.
We realize our proposal, in the case of extremal black holes, for which the
radial and temporal near horizon geometry is known to be
AdS$_2=SL(2,\mathbb{R})/SO(1,1,\mathbb{R})$. We implement its discretization by
replacing the set of real numbers $\mathbb{R}$ with the set of integers modulo
$N$, with AdS$_2$ going over to the finite geometry
AdS$_2[N]=SL(2,\mathbb{Z}_N)/SO(1,1,\mathbb{Z}_N)$.
  We model the dynamics of the microscopic degrees of freedom by generalized
Arnol'd cat maps, ${\sf A}\in SL(2,\mathbb{Z}_N)$, which are isometries of the
geometry at both the classical and quantum levels.
  These exhibit well studied properties of strong arithmetic chaos, dynamical
entropy, nonlocality and factorization in the cutoff discretization $N$, which
are crucial for fast quantum information processing.
  We construct, finally, a new kind of unitary and holographic correspondence,
for AdS$_2[N]$/CFT$_1[N]$, via coherent states of both the bulk and boundary
geometries.Comment: 33 pages LaTeX2e, 1 JPEG figure. Typos corrected, references added.
  Clarification of several points in the abstract and the tex
The spatiokinematical structure of H_2O and OH masers in the "water
  fountain" source IRAS 18460-0151

Using the Very Long Baseline Array and the European VLBI Network, we have
observed 22.2 GHz H_2O and 1612 MHz OH masers in the "water fountain" source
IRAS 18460-0151. The H_2O maser spectrum has a very wide line-of-sight velocity
range (~310 km/s) and consists of three groups of emission features at the
blue-shifted (-68 km/s <~ V_LSR <~ -17 km/s) and red-shifted (V_LSR ~= 240
km/s) edges as well as around the systemic velocity (112 km/s <~ V_LSR <~ 133
km/s). The first two H_2O spectral components exhibit a highly-collimated
high-velocity bipolar jet on the sky, with an angular separation of ~120
milliarcseconds (mas) (240 AU in linear length) and a three-dimensional flow
velocity of ~160 km/s. The flow dynamical age is estimated to be only ~6 yr (at
the time of the observation epochs of 2006--2007). Interestingly, the systemic
velocity component clearly exhibits a spherically-expanding outflow with a
radius of ~36 AU and a flow velocity of ~9 km/s. On the other hand, the OH
maser spectrum shows double peaks with a velocity separation of ~25 km/s
(V_LSR=$111--116 and 138--141 km/s), as typically seen in circumstellar
envelopes of OH/IR stars. The angular offset between the velocity-integrated
brightness peaks of the two high-velocity H_2O components is ~25 mas (50 AU).
The offset direction and the alignment of the red-shifted maser spots are
roughly perpendicular to the axis of the H_2O maser flow. High-accuracy
astrometry for the H_2O and OH masers demonstrates that the collimated fast jet
and the slowly expanding outflow originate from a single or multiple sources
which are located within 15 mas (30 AU). On the other hand, the estimated
systemic velocity of the collimated jet (V_sys ~87--113 km/s) has a large
uncertainty. This makes it difficult to provide strong constraints on models of
the central stellar system of IRAS 18460-0151.Comment: 25 pages, 5 figures, 8 tables, accepted for publication in Ap
The regularization and determination of the Yang-Mills vacuum wave
  functional in three dimensions at O(e^2)

We complete the computation of the Yang-Mills vacuum wave functional in three
dimensions at weak coupling with O(e^2) precision. We use two different methods
to solve the functional Schroedinger equation. One of them generalizes to
O(e^2) the method followed by Hatfield at O(e). The other uses the weak
coupling version of the gauge invariant formulation of the Schroedinger
equation and the ground state wave functional followed by Karabali, Nair, and
Yelnikov. These methods need to be carefully regularized to yield correct
results. This is done in this paper with full detail.Comment: 37 pages, 1 figure, extended conclusions and added demonstration of
  hermiticity of regularized Hamiltonian, one new reference. Physics unchanged.
  To meet journal versio
Vacuum structure in a chiral R+R^n modification of pure supergravity

We discuss an ${\cal R}+{\cal R}^n$ class of modified ${\cal N}=1$, D=4
supergravity models where the deformation is a monomial ${\cal R}^n\big|_F$ in
the chiral scalar curvature multiplet ${\cal R}$ of the "old minimal" auxiliary
field formulation. The scalaron and goldstino multiplets are dual to each other
in this theory. Since one of them is not dynamical, this theory, as recently
shown, cannot be used as the supersymmetric completion of $R+R^n$ gravity. This
is confirmed by investigating the scalar potential and its critical points in
the dual standard supergravity formulation with a single chiral multiplet with
specific K\"ahler potential and superpotential. We study the vacuum structure
of this dual theory and we find that there is always a supersymmetric Minkowski
critical point which however is pathological for $n\geq 3$ as it corresponds to
a corner ($n=3$) and a cusp ($n>3$) point of the potential. For $n>3$ an
anti-de Sitter regular supersymmetric vacuum emerges. As a result, this class
of models are not appropriate to describe inflation. We also find the mass
spectrum and we provide a general formula for the masses of the scalars of a
chiral multiplet around the anti-de Sitter critical point and their relation to
$osp(1,4)$ unitary representations.Comment: 15 pages, 2 figures, v2: typos corrected, published in Phys. Lett.
Radiation Magnetohydrodynamics In Global Simulations Of Protoplanetary
  Disks

Our aim is to study the thermal and dynamical evolution of protoplanetary
disks in global simulations, including the physics of radiation transfer and
magneto-hydrodynamic (MHD) turbulence caused by the magneto-rotational
instability. We develop a radiative transfer method based on the flux-limited
diffusion approximation that includes frequency dependent irradiation by the
central star. This hybrid scheme is implemented in the PLUTO code. The focus of
our implementation is on the performance of the radiative transfer method.
Using an optimized Jacobi preconditioned BiCGSTAB solver, the radiative module
is three times faster than the MHD step for the disk setup we consider. We
obtain weak scaling efficiencies of 70% up to 1024 cores. We present the first
global 3D radiation MHD simulations of a stratified protoplanetary disk. The
disk model parameters are chosen to approximate those of the system AS 209 in
the star-forming region Ophiuchus. Starting the simulation from a disk in
radiative and hydrostatic equilibrium, the magnetorotational instability
quickly causes MHD turbulence and heating in the disk. For the disk parameters
we use, turbulent dissipation heats the disk midplane and raises the
temperature by about 15% compared to passive disk models. A roughly flat
vertical temperature profile establishes in the disk optically thick region
close to the midplane. We reproduce the vertical temperature profile with a
viscous disk models for which the stress tensor vertical profile is flat in the
bulk of the disk and vanishes in the disk corona. The present paper
demonstrates for the first time that global radiation MHD simulations of
turbulent protoplanetary disks are feasible with current computational
facilities. This opens up the windows to a wide range of studies of the
dynamics of protoplanetary disks inner parts, for which there are significant
observational constraints.Comment: Accepted to A&
Occupation times of exclusion processes with conductances

We obtain the fluctuations for the occupation time of one-dimensional
symmetric exclusion processes with speed change, where the transition rates
(conductances) are driven by a general function W. The approach does not
require sharp bounds on the spectral gap of the system nor the jump rates to be
bounded from above or below. We present some examples and for one of them, we
observe that the fluctuations of the current are trivial, but the fluctuations
of the occupation time are given by a fractional Brownian Motion. This shows
that, in general, the fluctuations of the current and of the occupation time
are not of same order.Comment: 20 page
Final charged-lepton angular distribution and possible anomalous
  top-quark couplings in p p -> t tbar X -> l^+ X'

Possible anomalous (or nonstandard) top-quark interactions with the gluon and
those with the W boson induced by SU(3) x SU(2) x U(1) gauge-invariant
dimension-6 effective operators are studied in p p -> t tbar X -> l^+ X' (l=e
or mu) at the Large Hadron Collider (LHC). The final charged-lepton (l^+)
angular distribution is first computed for nonvanishing nonstandard top-gluon
and top-W couplings with a cut on its transverse momentum. The
optimal-observable procedure is then applied to this distribution in order to
estimate the expected statistical uncertainties in measurements of those
couplings that contribute to this process in the leading order.Comment: latex_2e, 14 pages, 4 eps figure
Can Effective Field Theory of inflation generate large tensor-to-scalar
  ratio within Randall Sundrum single braneworld?

In this paper my prime objective is to explain the generation of large
tensor-to-scalar ratio from the single field sub-Planckian inflationary
paradigm within Randall Sundrum (RS) single braneworld scenario in a model
independent fashion. By explicit computation I have shown that the effective
field theory prescription of brane inflation within RS single brane setup is
consistent with sub- Planckian excursion of the inflaton field, which will
further generate large value of tensor-to-scalar ratio, provided the energy
density for inflaton degrees of freedom is high enough compared to the brane
tension in high energy regime. Finally, I have mentioned the stringent
theoretical constraint on positive brane tension, cut-off of the quantum
gravity scale and bulk cosmological constant to get sub-Planckian field
excursion along with large tensor-to-scalar ratio as recently observed by
BICEP2 or at least generates the tensor-to-scalar ratio consistent with the
upper bound of Planck (2013 and 2015) data and Planck+BICEP2+Keck Array joint
constraint.Comment: 20 pages, Revision accepted by Nuclear Physics
Speed of light in non-trivial vacua

We unify all existing results on the change of the speed of low--energy photons due to modifications of the vacuum, finding that it is given by a universal constant times the quotient of the difference of energy densities between the usual and modified vacua over the mass of the electron to the fourth power. Whether photons move faster or slower than c depends only on the lower or higher energy density of the modified vacuum, respectively. Physically, a higher energy density is characterized by the presence of additional particles (real or virtual) in the vacuum whereas a lower one stems from the absence of some virtual modes. We then carry out a systematic study of the speed of propagation of massless particles for several field theories up to two loops on a thermal vacuum. Only low--energy massless particles corresponding to a massive theory show genuine modifications of their speed while remaining massless. All other modifications are mass-related, or running mass-related. We also develop a formalism for the Casimir vacuum which parallels the thermal one and check that photons travel faster than c between plates
Direct Observation of Longitudinally Polarised $W^{\pm}$ Bosons

The three different helicity states of W bosons, produced in the reaction $e^+e^- \rightarrow W^+W^- \rightarrow \ell \nu q \overline{q}$are studied using leptonic and hadronic W decaysat $\sqrt{s}$ = 183 GeV and 189 GeV. The W polarisation is also measured as a function of the scattering angle between the $W^-$ and the direction of the $e^-$ beam. The analysis demonstrates that W bosons are produced with all three helicities, the longitudinal and the two transverse states.Combining the results from the two center--of--mass energies and with leptonic and hadronic Wdecays, the fraction of longitudinally polarised W bosons ismeasured to be 0.261 $\pm$ 0.051(stat.) $\pm$ 0.016(syst.) in agreement with the expectation from the Standard Model.The three different helicity states of W bosons, produced in the reaction e+e- -> W+W- -> l nu q q~ are studied using leptonic and hadronic W decays at sqrt{s}=183GeV and 189GeV. The W polarisation is also measured as a function of the scattering angle between the W- and the direction of the e- beam. The analysis demonstrates that W bosons are produced with all three helicities, the longitudinal and the two transverse states. Combining the results from the two center-of-mass energies and with leptonic and hadronic W decays, the fraction of longitudinally polarised W bosons is measured to be 0.261 +/- 0.051(stat.) +/- 0.016(syst.) in agreement with the expectation from the Standard Model.The three different helicity states of W ± bosons, produced in the reaction e + e − → W + W − → ℓνq q ̄ are studied using leptonic and hadronic W decays at s =183 GeV and 189 GeV. The W polarisation is also measured as a function of the scattering angle between the W − and the direction of the e − beam. The analysis demonstrates that W bosons are produced with all three helicities, the longitudinal and the two transverse states. Combining the results from the two center-of-mass energies and with leptonic and hadronic W decays, the fraction of longitudinally polarised W ± bosons is measured to be 0.261 ± 0.051(stat.) ± 0.016(syst.) in agreement with the expectation from the Standard Model
Nonlinear Self-Duality and Supersymmetry

We review self-duality of nonlinear electrodynamics and its extension to several Abelian gauge fields coupled to scalars. We then describe self-duality in supersymmetric models, both N = 1 and N = 2. The self-duality equations, which have to be satisfied by the action of any self-dual system, are found and solutions are discussed. One important example is the Born-Infeld action. We explain why the N = 2 supersymmetric actions proposed so far are not the correct world-volume actions for D3 branes in d = 6
A New Noncommutative Product on the Fuzzy Two-Sphere Corresponding to the Unitary Representation of SU(2) and the Seiberg-Witten Map

We obtain a new explicit expression for the noncommutative (star) product on the fuzzy two-sphere which yields a unitary representation. This is done by constructing a star product, $\star_{\lambda}$, for an arbitrary representation of SU(2) which depends on a continuous parameter $\lambda$ and searching for the values of $\lambda$ which give unitary representations. We will find two series of values: $\lambda = \lambda^{(A)}_j=1/(2j)$ and $\lambda=\lambda^{(B)}_j =-1/(2j+2)$, where j is the spin of the representation of SU(2). At $\lambda = \lambda^{(A)}_j$ the new star product $\star_{\lambda}$ has poles. To avoid the singularity the functions on the sphere must be spherical harmonics of order $\ell \leq 2j$ and then $\star_{\lambda}$ reduces to the star product $\star$ obtained by Preusnajder. The star product at $\lambda=\lambda^{(B)}_j$, to be denoted by $\bullet$, is new. In this case the functions on the fuzzy sphere do not need to be spherical harmonics of order $\ell \leq 2j$. Because in this case there is no cutoff on the order of spherical harmonics, the degrees of freedom of the gauge fields on the fuzzy sphere coincide with those on the commutative sphere. Therefore, although the field theory on the fuzzy sphere is a system with finite degrees of freedom, we can expect the existence of the Seiberg-Witten map between the noncommutative and commutative descriptions of the gauge theory on the sphere. We will derive the first few terms of the Seiberg-Witten map for the U(1) gauge theory on the fuzzy sphere by using power expansion around the commutative point $\lambda=0$
Periodic solutions for completely resonant nonlinear wave equations

We consider the nonlinear string equation with Dirichlet boundary conditions
$u_{xx}-u_{tt}=\phi(u)$, with $\phi(u)=\Phi u^{3} + O(u^{5})$ odd and analytic,
$\Phi\neq0$, and we construct small amplitude periodic solutions with frequency
$\o$ for a large Lebesgue measure set of $\o$ close to 1. This extends previous
results where only a zero-measure set of frequencies could be treated (the ones
for which no small divisors appear). The proof is based on combining the
Lyapunov-Schmidt decomposition, which leads to two separate sets of equations
dealing with the resonant and nonresonant Fourier components, respectively the
Q and the P equations, with resummation techniques of divergent powers series,
allowing us to control the small divisors problem. The main difficulty with
respect the nonlinear wave equations $u_{xx}-u_{tt}+ M u = \phi(u)$, $M\neq0$,
is that not only the P equation but also the Q equation is infinite-dimensiona
The Interpretation of Quantum Mechanics: Many Worlds or Many Words?

As cutting-edge experiments display ever more extreme forms of non-classical
behavior, the prevailing view on the interpretation of quantum mechanics
appears to be gradually changing. A (highly unscientific) poll taken at the
1997 UMBC quantum mechanics workshop gave the once all-dominant Copenhagen
interpretation less than half of the votes. The Many Worlds interpretation
(MWI) scored second, comfortably ahead of the Consistent Histories and Bohm
interpretations. It is argued that since all the above-mentioned approaches to
nonrelativistic quantum mechanics give identical cookbook prescriptions for how
to calculate things in practice, practical-minded experimentalists, who have
traditionally adopted the ``shut-up-and-calculate interpretation'', typically
show little interest in whether cozy classical concepts are in fact real in
some untestable metaphysical sense or merely the way we subjectively perceive a
mathematically simpler world where the Schrodinger equation describes
everything - and that they are therefore becoming less bothered by a profusion
of worlds than by a profusion of words.
  Common objections to the MWI are discussed. It is argued that when
environment-induced decoherence is taken into account, the experimental
predictions of the MWI are identical to those of the Copenhagen interpretation
except for an experiment involving a Byzantine form of ``quantum suicide''.
This makes the choice between them purely a matter of taste, roughly equivalent
to whether one believes mathematical language or human language to be more
fundamental.Comment: 6 pages. More details and links at
  http://www.sns.ias.edu/~max/everett.html (faster from the US), from
  http://www.mpa-garching.mpg.de/~max/everett.html (faster from Europe) or from
  max@ias.ed
Quantum State Reduction: An Operational Approach

A rigorous theory of quantum state reduction, the state change of the
measured system caused by a measurement conditional upon the outcome of
measurement, is developed fully within quantum mechanics without leading to the
vicious circle relative to the von Neumann chain. For the basis of the theory,
the local measurement theorem provides the joint probability distribution for
the outcomes of local successive measurements on a noninteracting entangled
system without assuming the projection postulate, and the quantum Bayes
principle enables us to determine operationally the quantum state from a given
information on the outcome of measurement.Comment: 12 pages, LaTeX, no figures, Fundamental problems in quantum theory
  workshop (August 1997, Baltimore), invited lectur
Subarcsecond imaging of the NGC 6334 I(n) protocluster : two dozen compact sources and a massive disk candidate

Using the Submillimeter Array (SMA) and Karl G. Jansky Very Large Array, we have imaged the massive protocluster NGC 6334 I(N) at high angular resolution (0.″5 ∼ 650 AU) from 6 cm to 0.87 mm, detecting 18 new compact continuum sources. Three of the new sources are coincident with previously identified HO masers. Together with the previously known sources, these data bring the number of likely protocluster members to 25 for a protostellar density of ∼700 pc-3. Our preliminary measurement of the Q-parameter of the minimum spanning tree is 0.82 - close to the value for a uniform volume distribution. All of the (nine) sources with detections at multiple frequencies have spectral energy distributions consistent with dust emission, and two (SMA 1b and SMA 4) also have long wavelength emission consistent with a central hypercompact H II region. Thermal spectral line emission, including CH3CN, is detected in six sources: LTE model fitting of CH3CN (J = 12-11) yields temperatures of 72-373 K, confirming the presence of multiple hot cores. The fitted LSR velocities range from -3.3 to -7.0 km s-1, with an unbiased mean square deviation of 2.05 km s-1, implying a protocluster dynamical mass of 410 ± 260 M ☉. From analysis of a wide range of hot core molecules, the kinematics of SMA 1b are consistent with a rotating, infalling Keplerian disk of diameter 800 AU and enclosed mass of 10-30 M ☉ that is perpendicular (within 1°) to the large-scale bipolar outflow axis. A companion to SMA 1b at a projected separation of 0.″45 (590 AU; SMA 1d), which shows no evidence of spectral line emission, is also confirmed. Finally, we detect one 218.4400 GHz and several 229.7588 GHz Class-I CH3OH masers.Publisher PDFPeer reviewe