title: Antimatter interferometry for gravity measurements

abstract:
  We describe a light-pulse atom interferometer that is suitable for any
species of atom and even for electrons and protons as well as their
antiparticles, in particular for testing the Einstein equivalence principle
with antihydrogen. The design obviates the need for resonant lasers through
far-off resonant Bragg beam splitters and makes efficient use of scarce atoms
by magnetic confinement and atom recycling. We expect to reach an initial
accuracy of better than 1% for the acceleration of free fall of antihydrogen,
which can be improved to the part-per million level.

categories: physics.atom-ph gr-qc hep-ph physics.plasm-ph


title:
Bipolar magnetic structures driven by stratified turbulence with a
  coronal envelope

abstract:
  We report the spontaneous formation of bipolar magnetic structures in direct
numerical simulations of stratified forced turbulence with an outer coronal
envelope. The turbulence is forced with transverse random waves only in the
lower (turbulent) part of the domain. Our initial magnetic field is either
uniform in the entire domain or confined to the turbulent layer. After about
1--2 turbulent diffusion times, a bipolar magnetic region of vertical field
develops with two coherent circular structures that live during one turbulent
diffusion time, and then decay during 0.5 turbulent diffusion times. The
resulting magnetic field strengths inside the bipolar region are comparable to
the equipartition value with respect to the turbulent kinetic energy. The
bipolar magnetic region forms a loop-like structure in the upper coronal layer.
We associate the magnetic structure formation with the negative effective
magnetic pressure instability in the two-layer model.


title:
Operator theory and function theory in Drury-Arveson space and its
  quotients

abstract:
  The Drury-Arveson space $H^2_d$, also known as symmetric Fock space or the
$d$-shift space, is a Hilbert function space that has a natural $d$-tuple of
operators acting on it, which gives it the structure of a Hilbert module. This
survey aims to introduce the Drury-Arveson space, to give a panoramic view of
the main operator theoretic and function theoretic aspects of this space, and
to describe the universal role that it plays in multivariable operator theory
and in Pick interpolation theory.


title: Truncated convolution of character sheaves

abstract:
  Let G be a reductive connected group over an algebraic closure of a finite
field. I define a tensor structure on the category of perverse sheaves on G
which are direct sums of unipotent character sheaves in a fixed two-sided cell,
in accordance with a conjecture I have made in 2004. I also show that that the
resulting monoidal category is equivalent to the centre of a monoidal category
which I defined in 1997 (a categorical version of the J-ring attached to the
same two-sided cell), thus verifying a conjecture of Bezrukavnikov, Finkelberg,
Ostrik. A possible interpretation of unipotent characters associated to a
finite noncrystallographic Coxeter group is given.


title: A universal feature of CFT Renyi entropy

abstract:
  We show that for a d-dimensional CFT in flat space, the Renyi entropy S_q
across a spherical entangling surface has the following property: in an
expansion around q=1, the first correction to the entanglement entropy is
proportional to C_T, the coefficient of the stress tensor vacuum two-point
function, with a fixed d-dependent coefficient. This is equivalent to a similar
statement about the free energy of CFTs living on S^1 x H^{d-1} with inverse
temperature \beta=2\pi q. In addition to furnishing a direct argument
applicable to all CFTs, we exhibit this result using a handful of gravity and
field theory computations. Knowledge of C_T thus doubles as knowledge of Renyi
entropies in the neighborhood of q=1, which we use to establish new results in
3d vector models at large N.


title: On Sharp Thresholds in Random Geometric Graphs

abstract:
  We give a characterization of vertex-monotone properties with sharp
thresholds in a Poisson random geometric graph or hypergraph. As an application
we show that a geometric model of random k-SAT exhibits a sharp threshold for
satisfiability.


title: Imaging the Kondo Insulating Gap on SmB6

abstract:
  Topological insulators host spin-polarized surface states which robustly span
the band gap and hold promise for novel applications. Recent theoretical
predictions have suggested that topologically protected surface states may
similarly span the hybridization gap in some strongly correlated heavy fermion
materials, particularly SmB6. However, the process by which the Sm 4f electrons
hybridize with the 5d electrons on the surface of SmB6, and the expected
Fermi-level gap in the density of states out of which the predicted topological
surface states must arise, have not been directly measured. We use scanning
tunneling microscopy to conduct the first atomic resolution spectroscopic study
of the cleaved surface of SmB6, and to reveal a robust hybridization gap which
universally spans the Fermi level on four distinct surface morphologies despite
shifts in the f band energy. Using a cotunneling model, we separate the density
of states of the hybridized bands from which the predicted topological surface
states must be disentangled. On all surfaces we observe residual spectral
weight spanning the hybridization gap down to the lowest T, which is consistent
with a topological surface state.


title:
Effect of Spin Accumulation at Co/Pt Interfaces on Anomalous Hall Effect
  in Pt/Co/Pt Trilayers

abstract:
  As current flows through a Pt/Co/Pt trilayer, spin Hall effect induced by
charge current in the Pt layer leads to spin accumulation at the Co/Pt
interfaces. Our experiment and calculation show an indication of the effect of
spin accumulation at the Co/Pt interfaces on anomalous Hall coefficient in the
Pt/Co/Pt sandwich, which depends on the Pt layer thickness and spin diffusion
length in Pt layer. The ratio of the longitudinal current in the Pt cap layer
due to anomalous Hall effect to the injected transverse current in the Co layer
increases with the Pt cap layer thickness.


title: Designing the statistically optimal drug for cancer therapy

abstract:
  Cancer and healthy cells have distinct distributions of molecular properties
and thus respond differently to drugs. Cancer drugs ideally kill cancer cells
while limiting harm to healthy cells. However, the inherent variance among
cells in both cancer and healthy cell populations increases the difficulty of
selective drug action. Here we propose a classification framework based on the
idea that an ideal cancer drug should maximally discriminate between cancer and
healthy cells. We first explore how molecular markers can be used to
discriminate cancer cells from healthy cells on a single cell basis, and then
how the effects of drugs are statistically predicted by these molecular
markers. We then combine these two ideas to show how to optimally match drugs
to tumor cells. We find that expression levels of a handful of genes suffice to
discriminate well between individual cells in cancer and healthy tissue. We
also find that gene expression predicts the efficacy of cancer drugs,
suggesting that the cancer drugs act as classifiers using gene profiles. In
agreement with our first finding, a small number of genes predict drug efficacy
well. Finally, we formulate a framework that defines an optimal drug, and
predicts drug cocktails that may target cancer more accurately than the
individual drugs alone. Conceptualizing cancer drugs as solving a
discrimination problem in the high-dimensional space of molecular markers
promises to inform the design of new cancer drugs and drug cocktails.


title:
MaGICC-WDM: the effects of warm dark matter in hydrodynamical
  simulations of disc galaxy formation

abstract:
  We study the effect of warm dark matter (WDM) on hydrodynamic simulations of
galaxy formation as part of the Making Galaxies in a Cosmological Context
(MaGICC) project. We simulate three different galaxies using three WDM
candidates of 1, 2 and 5 keV and compare results with pure cold dark matter
simulations. WDM slightly reduces star formation and produces less centrally
concentrated stellar profiles. These effects are most evident for the 1 keV
candidate but almost disappear for $m_{\mathrm{WDM}}>2$ keV. All simulations
form similar stellar discs independent of WDM particle mass. In particular, the
disc scale length does not change when WDM is considered. The reduced amount of
star formation in the case of 1 keV particles is due to the effects of WDM on
merging satellites which are on average less concentrated and less gas rich.
The altered satellites cause a reduced starburst during mergers because they
trigger weaker disc instabilities in the main galaxy. Nevertheless we show that
disc galaxy evolution is much more sensitive to stellar feedback than it is to
WDM candidate mass. Overall we find that WDM, especially when restricted to
current observational constraints ($m_{\mathrm{WDM}}>2$ keV), has a minor
impact on disc galaxy formation.


title:
Significant Enhancement of Neutralino Dark Matter Annihilation from
  Electroweak Bremsstrahlung

abstract:
  Indirect searches for the cosmological dark matter have become ever more
competitive during the past years. Here, we report the first full calculation
of leading electroweak corrections to the annihilation rate of supersymmetric
neutralino dark matter. We find that these corrections can be huge, partially
due to contributions that have been overlooked so far. Our results imply a
significantly enhanced discovery potential of this well motivated dark matter
candidate with current and upcoming cosmic ray experiments, in particular for
gamma rays and models with somewhat small annihilation rates at tree level.


title: Linking Natural Supersymmetry to Flavour Physics

abstract:
  With the aim of linking natural supersymmetry to flavour physics, a model is
proposed based on a family symmetry G \times U(1), where G is a discrete
nonabelian subgroup of SU(2), with both F-term and (abelian) D-term
supersymmetry breaking. A good fit to the fermion masses and mixing is obtained
with the same U(1) charges for the left- and right- handed quarks of the first
two families and the right-handed bottom quark, and with zero charge for the
left-handed top-bottom doublet and the the right handed top. The model shows an
interesting indirect correlation between the correct prediction for the
V_{ub}/V_{cb} ratio and large right-handed rotations in the (s,b) sector,
required to diagonalise the Yukawa matrix. For the squarks, one obtains almost
degenerate first two generations. The main source of the FCNC and CP violation
effects is the splitting between the first two families and the right-handed
sbottom determined by the relative size of F-term and D-term supersymmetry
breaking. The presence of the large right-handed rotation implies that the
bounds on the masses of the first two families of squarks and the right handed
sbottom are in a few to a few tens TeV range. The picture that emerges is light
stops and left handed sbottom and much heavier other squarks.


title: Ferromagnetic response of a "high-temperature" quantum antiferromagnet

abstract:
  We study the finite temperature antiferromagnetic phase of the ionic Hubbard
model in the strongly interacting limit using quantum Monte Carlo based
dynamical mean field theory. We find that the ionic potential plays a dual role
in determining the antiferromagnetic order. A small ionic potential (compared
to Hubbard repulsion) increases the super-exchange coupling in the projected
sector of the model, leading to an increase in the Neel temperature of the
system. A large ionic potential leads to resonance between projected
antiferromagnetically ordered configurations and density ordered configurations
with double occupancies, thereby killing antiferromagnetism in the system. This
novel way of degrading antiferromagnetism leads to spin polarization of the low
energy single particle density of states. The dynamic response of the system
thus mimics ferromagnetic behaviour, although the system is still an
antiferromagnet in terms of the static spin order.


title: Unifying Geometrical Representations of Gauge Theory

abstract:
  We unify three approaches within the vast body of gauge-theory research that
have independently developed distinct representations of a geometrical
surface-like structure underlying the vector-potential. The three approaches
that we unify are: those who use the compactified dimensions of Kaluza-Klein
theory, those who use Grassmannian models (also called gauge theory embedding
or $CP^{N-1}$ models) to represent gauge fields, and those who use a hidden
spatial metric to replace the gauge fields. In this paper we identify a
correspondence between the geometrical representations of the three
schools.Each school was mostly independently developed, does not compete with
other schools, and attempts to isolate the gauge-invariant geometrical
surface-like structures that are responsible for the resulting physics. By
providing a mapping between geometrical representations, we hope physicists can
now isolate representation-dependent physics from gauge-invariant physical
results and share results between each school. We provide visual examples of
the geometrical relationships between each school for $U(1)$ electric and
magnetic fields. We highlight a first new result: in all three representations
a static electric field (electric field from a fixed ring of charge or a sphere
of charge) has a hidden gauge-invariant time dependent surface that is
underlying the vector potential.


title: Wide Angle Effects in Future Galaxy Surveys

abstract:
  Current and future galaxy surveys cover a large fraction of the entire sky
with a significant redshift range, and the recent theoretical development shows
that general relativistic effects are present in galaxy clustering on very
large scales. This trend has renewed interest in the wide angle effect in
galaxy clustering measurements, in which the distant-observer approximation is
often adopted. Using the full wide-angle formula for computing the
redshift-space correlation function, we show that compared to the sample
variance, the deviation in the redshift-space correlation function from the
simple Kaiser formula with the distant-observer approximation is negligible in
galaxy surveys such as the SDSS, Euclid and the BigBOSS, if the theoretical
prediction from the Kaiser formula is properly averaged over the survey volume.
We also find corrections to the wide-angle formula and clarify the confusion in
literature between the wide angle effect and the velocity contribution in
galaxy clustering. However, when the FKP method is applied, substantial
deviations can be present in the power spectrum analysis in future surveys, due
to the non-uniform distribution of galaxy pairs.


title: Measuring CP Violation in $h \to \tau^+ \tau^-$ at Colliders

abstract:
  We investigate the LHC and Higgs Factory prospects for measuring the CP phase
in the Higgs-tau-tau coupling. Currently this phase can be anywhere between 0
degrees (CP even) and 90 degrees (CP odd). A new, ideal observable is
identified from an analytic calculation for the $\tau^\pm \to \rho^\pm\nu \to
\pi^\pm \pi^0 \nu$ channel. It is demonstrated to have promising sensitivity at
the LHC and superior sensitivity at the ILC compared to previous proposals. Our
observable requires the reconstruction of the internal substructure of decaying
taus but does not rely on measuring the impact parameter of tau decays. It is
the first proposal for such a measurement at the LHC. For the 14 TeV LHC, we
estimate that about 1 ab$^{-1}$ data can discriminate CP-even versus CP-odd at
the $5\sigma$ level. With 3 ab$^{-1}$, the CP phase should be measurable to an
accuracy of $\sim 11$ degrees. At an $e^+e^-$ Higgs Factory, we project that a
250 GeV run with 1 ab$^{-1}$ luminosity can measure the phase to $\sim 4.4$
degrees accuracy.


title:
FRW cosmologies and hyperscaling-violating geometries: higher curvature
  corrections, ultrametricity, Q-space/QFT duality, and a little string theory

abstract:
  We analyze flat FRW cosmologies and hyperscaling-violating geometries by
emphasizing the analytic continuation between them and their scale covariance.
We exhibit two main calculations where this point of view is useful. First,
based on the scale covariance, we show that the structure of higher curvature
corrections to Einstein's equation is very simple. Second, in the context of
accelerated FRW cosmologies, also known as Q-space, we begin by calculating the
Bunch-Davies wavefunctional for a massless scalar field and considering its
interpretation as a generating functional of correlation functions of a
holographic dual. We use this to conjecture a Q-space/QFT duality, a natural
extension of dS/CFT, and argue that the Euclidean dual theory violates
hyperscaling. This proposal, when extended to epochs in our own cosmological
history like matter or radiation domination, suggests a holographically dual
description via RG phases which violate hyperscaling. We further use the
wavefunctional to compute Anninos-Denef overlaps and show that the ultrametric
structure discovered for de Sitter becomes sharper in accelerated FRW
cosmologies as the acceleration slows. The substitution $d -->
d_{eff}=d-\theta$ permeates and illuminates the discussion of wavefunctionals
and overlaps in FRW cosmologies, allowing one to predict the sharpened
structure. We try to find an alternate manifestation of this ultrametric
structure by studying the connection of the $\theta --> -\infty$ background to
little string theory.


title: Consequences of Weyl Consistency Conditions

abstract:
  The running of quantum field theories can be studied in detail with the use
of a local renormalization group equation. The usual beta-function effects are
easy to include, but by introducing spacetime-dependence of the various
parameters of the theory one can efficiently incorporate renormalization
effects of composite operators as well. An illustration of the power of these
methods was presented by Osborn in the early 90s, who used consistency
conditions following from the Abelian nature of the Weyl group to rederive
Zamolodchikov's c-theorem in d=2 spacetime dimensions, and also to obtain a
perturbative a-theorem in d=4. In this work we present an extension of Osborn's
work to d=6 and to general even d. We compute the full set of Weyl consistency
conditions, and we discover among them a candidate for an a-theorem in d=6,
similar to the d=2,4 cases studied by Osborn. Additionally, we show that in any
even spacetime dimension one finds a consistency condition that may serve as a
generalization of the c-theorem, and that the associated candidate c-function
involves the coefficient of the Euler term in the trace anomaly. Such a
generalization hinges on proving the positivity of a certain "metric" in the
space of couplings.


title: Gamma-Ray bursts: Energetics and Prompt Correlations

abstract:
  A model is presented here that is capable of simultaneously describing the
luminosity function and the underlying joint population distribution of the
prompt spectral and temporal parameters of Gamma-Ray Bursts (GRBs), subject to
the detection threshold of gamma-ray instruments--in particular, BATSE and
Fermi. Based on 2130 GRB prompt emission data in the BATSE catalog, I show that
the population properties of the two classes of GRBs -- Long and Short
durations -- bear striking similarities in the 4-dimensional space of prompt
parameters: peak luminosity (Liso), total isotropic emission (Eiso),
time-integrated spectral peak energy (Ep,z) and the prompt duration (T90,z).
The two well-known Amati (Eiso-Ep,z) and Yonetoku (Liso-Ep,z) relations are
shown to be highly affected by selection effects, undermining the legitimacy of
their frequent uses in the studies of Dark Energy's equation of state and
different cosmological models. In particular, I show that the slope of the
Amati relation is likely in the range 0.2-0.3, corresponding to a Pearson's
correlation strength of rho=0.58\pm0.04. This predicted slope is significantly
(>16sigma) less than the value currently perceived by the GRB community
(~0.56). I argue that similar Eiso-Ep,z and Liso-Ep,z relations with
approximately same strength and significance should exist in the population of
Short GRBs. Also predicted by the model is the strong positive correlation of
the prompt emission duration (e.g., T90,z) with Eiso and Liso in both classes
of Short and Long GRBs.


title:
Clustering in the Phase Space of Dark Matter Haloes. I. Results from the
  Aquarius simulations

abstract:
  We present a novel perspective on the clustering of dark matter in phase
space by defining the particle phase space average density ($P^2SAD$) as a
two-dimensional extension of the two-point correlation function averaged within
a certain volume in phase space. This statistics is a sensitive measure of
small scale (sub-)structure of dark matter haloes. By analysing the structure
of $P^2SAD$ in Milky-Way-size haloes using the Aquarius simulations, we find it
to be nearly universal at small scales, i.e. small separations in phase space,
where substructures dominate. This remarkable universality occurs across time
and in regions of substantially different ambient densities (by nearly four
orders of magnitude), with typical variations in $P^2SAD$ of a factor of a few.
The maximum variations occur in regions where substructures have been strongly
disrupted. The universality is also preserved across haloes of similar mass but
diverse mass accretion histories and subhalo distributions. The universality is
also broken at large scales, where the smooth dark matter distribution in the
halo dominates. Although at small scales the structure of $P^2SAD$ is roughly
described by a subhalo model, we argue that the simulation data is better
fitted by a family of superellipse contours. This functional shape is inspired
by a model that extends the stable clustering hypothesis into phase space. In a
companion paper, we refine this model and show its advantages as a method to
obtain predictions for non-gravitational signatures of dark matter.


title:
The Dust Attenuation Law in Distant Galaxies: Evidence for Variation
  with Spectral Type

abstract:
  This letter utilizes composite spectral energy distributions (SEDs)
constructed from NEWFIRM Medium-Band Survey photometry to constrain the dust
attenuation curve in 0.5<z<2.0 galaxies. Based on similarities between the full
SED shapes (0.3-8 micron), we have divided galaxies in 32 different spectral
classes and stacked their photometry. As each class contains galaxies over a
range in redshift, the resulting rest-frame SEDs are well-sampled in wavelength
and show various spectral features including Halpha and the UV dust bump at
2175 Angstrom. We fit all composite SEDs with flexible stellar population
synthesis models, while exploring attenuation curves with varying slopes and UV
bump strengths. The Milky Way and Calzetti law provide poor fits at UV
wavelengths for nearly all SEDs. Consistent with previous studies, we find that
the best-fit attenuation law varies with spectral type. There is a strong
correlation between the best-fit dust slope and UV bump strength, with steeper
laws having stronger bumps. Moreover, the attenuation curve correlates with
specific star formation rate (SFR), with more active galaxies having shallower
dust curves and weaker bumps. There is also a weak correlation with
inclination. The observed trends can be explained by differences in the
dust-to-star geometry, a varying grain size distribution, or a combination of
both. Our results have several implications for galaxy evolution studies.
First, the assumption of a universal dust model leads to biases in derived
galaxy properties. Second, the presence of a dust bump may result in
underestimated values for the UV slope, used to correct SFRs of distant
galaxies.


title:
Numerical evidence for strong randomness scaling at a
  superfluid-insulator transition of one-dimensional bosons

abstract:
  We present numerical evidence from Monte Carlo simulations that the
superfluid-insulator quantum phase transition of interacting bosons subject to
strong disorder in one dimension is controlled by the strong-randomness
critical point. At this critical point the distribution of superfluid stiffness
over disorder realizations develops a power-law tail reflecting a universal
distribution of weak links. The Luttinger parameter on the other hand does not
take on a universal value at this critical point, in marked contrast to the
known Berezinskii-Kosterlitz-Thouless-like superfluid-insulator transition in
weakly disordered systems. We develop a finite-size scaling procedure which
allows us to directly compare the numerical results from systems of linear size
up to 1024 sites with theoretical predictions obtained by Altman et al. [ Phys.
Rev. Lett. 93 150402 (2004)] using a strong disorder renormalization group
approach. The data shows good agreement with the scaling expected at the
strong-randomness critical point.


title:
Dissecting the properties of optically-thick hydrogen at the peak of
  cosmic star formation history

abstract:
  We present results of a blind survey of Lyman limit systems (LLSs) detected
in absorption against 105 quasars at z~3 using the blue sensitive MagE
spectrograph at the Magellan Clay telescope. By searching for Lyman limit
absorption in the wavelength range ~3000-4000A, we measure the number of LLSs
per unit redshift l(z)=1.21+/-0.28 at z~2.8. Using a stacking analysis, we
further estimate the mean free path of ionizing photons in the z~3 Universe
lambda^912 = 100+/-29 Mpc/h_70.4. Combined with our LLS survey, we conclude
that systems with log N_HI >= 17.5 cm^-2 contribute only ~40% to the observed
mean free path at these redshifts. Further, with the aid of photo-ionization
modeling, we infer that a population of ionized and metal poor systems is
likely required to reproduce the metal line strengths observed in a composite
spectrum of 20 LLSs with N_HI = 17.5-19 cm^-2 at z~2.6-3.0. Finally, with a
simple toy model, we deduce that gas in the halos of galaxies can alone account
for the totality of LLSs at z<~3, but a progressively higher contribution from
the intergalactic medium is required beyond z~3.5. We also show how the weakly
evolving number of LLSs per unit redshift at z<~3 can be modeled either by
requiring that the spatial extent of the circumgalactic medium is redshift
invariant in the last ~10 Gyr of cosmic evolution or by postulating that LLSs
arise in halos that are rare fluctuations in the density field at each
redshift.


title: Extended Supersymmetry on Curved Spaces

abstract:
  We study N=2 superconformal theories on Euclidean and Lorentzian
four-manifolds with a view toward applications to holography and localization.
The conditions for supersymmetry are equivalent to a set of differential
constraints including a "generalised" conformal Killing spinor equation
depending on various background fields. We solve these equations in the general
case and give very explicit expressions for the auxiliary fields that we need
to turn on to preserve some supersymmetry. As opposed to what has been observed
for the N=1 case, the conditions for unbroken supersymmetry turn out to be
almost independent of the signature of spacetime, with the exception of few
degenerate cases including the topological twist. Generically, the only
geometrical constraint coming from supersymmetry is the existence of a
conformal Killing vector on the manifold, all other constraints determine the
background auxiliary fields.


title: From Resonant to Broadband Searches for WISPy Cold Dark Matter

abstract:
  Dark matter may consist of light, very weakly interacting bosons, produced
non-thermally in the early Universe. Prominent examples of such very weakly
interacting slim particles (WISPs) are axions and hidden photons. Direct
detection experiments for such particles are based on the conversion of these
particles into photons. This can be done in resonant cavities, featuring a
resonant enhancement, or by using suitably shaped reflecting surfaces that
allow for broadband searches. In this note we want to elucidate the relation
between the two setups and study the transition from resonant to broadband
searches. This then allows to determine the sensitivity of off-resonance cavity
searches for cavities much larger than the wavelength of the generated photons.


title:
Constructing analytical solutions of linear perturbations of inflation
  with modified dispersion relations

abstract:
  We develop a technique to construct analytical solutions of the linear
perturbations of inflation with a nonlinear dispersion relation, due to quantum
effects of the early universe. Error bounds are given and studied in detail.
The analytical solutions describe the exact evolution of the perturbations
extremely well even when only the first-order approximations is used.


title: Are IceCube neutrinos unveiling PeV-scale decaying dark matter?

abstract:
  Recent observations by IceCube, notably two PeV cascades accompanied by
events at energies ~ (30-400) TeV, are clearly in excess over atmospheric
background fluxes and beg for an astroparticle physics explanation. Although
some models of astrophysical accelerators can account for the observations
within current statistics, intriguing features in the energy and possibly
angular distributions of the events make worth exploring alternatives. Here, we
entertain the possibility of interpreting the data with a few PeV mass scale
decaying Dark Matter, with lifetime of the order of 10^27 s. We discuss generic
signatures of this scenario, including its unique energy spectrum distortion
with respect to the benchmark $E_\nu^{-2}$ expectation for astrophysical
sources, as well as peculiar anisotropies. A direct comparison with the data
show a good match with the above-mentioned features. We further discuss
possible future checks of this scenario.


title:
Transient adhesion and conductance phenomena in initial nanoscale
  mechanical contacts between dissimilar metals

abstract:
  We report on transient adhesion and conductance phenomena associated with tip
wetting in mechanical contacts produced by the indentation of a clean W(111)
tip into a Au(111) surface. A combination of atomic force microscopy and
scanning tunneling microscopy was used to carry out indentation and to image
residual impressions in ultra-high vacuum. The ~7 nm radii tips used in these
experiments were prepared and characterized by field ion microscopy in the same
instrument. The very first indentations of the tungsten tips show larger
conductance and pull-off adhesive forces than subsequent indentations. After
~30 indentations to a depth of ~1.7 nm, the maximum conductance and adhesion
forces reach steady-state values approximately 12x and 6x smaller than their
initial value. Indentation of W(111) tips into Cu(100) was also performed to
investigate the universality of tip wetting phenomena with a different
substrate. We propose a model from contact mechanics considerations which
quantitatively reproduces the observed decay rate of the conductance and
adhesion drops with a 1/e decay constant of 9-14 indentation cycles. The
results show that the surface composition of an indenting tip plays an
important role in defining the mechanical and electrical properties of
indentation contacts.


title:
SO(10)-inspired solution to the problem of the initial conditions in
  leptogenesis

abstract:
  We show that, within SO(10)-inspired leptogenesis, there exists a solution,
with definite constraints on low energy neutrino parameters, able
simultaneously to reproduce the observed baryon asymmetry and to satisfy the
conditions for the independence of the final asymmetry of the initial
conditions (strong thermal leptogenesis). We find that the wash-out of a
pre-existing asymmetry as large as O(0.1) requires: i) reactor mixing angle in
the range \theta_13 = (2 - 20) degrees, in agreement with the experimental
result \theta_13 = (8 - 10) degrees; ii) atmospheric mixing angle in the range
\theta_23 = (16 - 41) degrees, compatible only with current lowest
experimentally allowed values; iii) Dirac phase in the range \delta \simeq
-\pi/2 - \pi/5, with the bulk of the solutions around \delta \simeq -\pi/5 and
such that sign(J_CP)= - sign(\eta_B); iv) neutrino masses m_i normally ordered;
v) lightest neutrino mass in the range m_1 \simeq (15 - 25) meV, corresponding
to \sum_i m_i \simeq (85 - 105) meV; vi) neutrinoless double beta decay
(0\nu\beta\beta) effective neutrino mass m_ee \simeq 0.8 m_1. All together this
set of predictive constraints characterises the solution quite distinctively,
representing a difficultly forgeable, fully testable, signature. In particular,
the condition m_ee \simeq 0.8 m_1 \simeq 15 meV can be tested by cosmological
observations and (ultimately) by 0\nu\beta\beta experiments. We also discuss
different aspects such as theoretical uncertainties, stability under variation
of the involved parameters, form of the orthogonal and RH neutrino mixing
matrices.


title:
Resurgence theory, ghost-instantons, and analytic continuation of path
  integrals

abstract:
  A general quantum mechanical or quantum field theoretical system in the path
integral formulation has both real and complex saddles (instantons and
ghost-instantons). Resurgent asymptotic analysis implies that both types of
saddles contribute to physical observables, even if the complex saddles are not
on the integration path i.e., the associated Stokes multipliers are zero. We
show explicitly that instanton-anti-instanton and ghost--anti-ghost saddles
both affect the expansion around the perturbative vacuum. We study a self-dual
model in which the analytic continuation of the partition function to negative
values of coupling constant gives a pathological exponential growth, but a
homotopically independent combination of integration cycles (Lefschetz
thimbles) results in a sensible theory. These two choices of the integration
cycles are tied with a quantum phase transition. The general set of ideas in
our construction may provide new insights into non-perturbative QFT, string
theory, quantum gravity, and the theory of quantum phase transitions.


title:
Warm dark matter primordial spectra and the onset of structure formation
  at redshift z

abstract:
  Analytic formulas reproducing the warm dark matter (WDM) primordial spectra
are obtained for WDM particles decoupling in and out of thermal equilibrium
which provide the initial data for WDM non-linear structure formation. We
compute and analyze the corresponding WDM overdensities and compare them to the
CDM case. We consider the ratio of the WDM to CDM primordial spectrum and the
WDM to CDM overdensities: they turn to be self-similar functions of k/k_{1/2}
and R/R_{1/2} respectively, k_{1/2} and R_{1/2} being the wavenumber and length
where the WDM spectrum and overdensity are 1/2 of the respective CDM
magnitudes. Both k_{1/2} and R_{1/2} show scaling as powers of the WDM particle
mass m while the self-similar functions are independent of m. The WDM
primordial spectrum sharply decreases around k_{1/2} with respect to the CDM
spectrum, while the WDM overdensity slowly decreases around R_{1/2}. The
nonlinear regions where WDM structure formation takes place are shown and
compared to those in CDM: the WDM non-linear structures start to form later
than in CDM, and as a general trend, decreasing the DM particle mass delays the
onset of the non-linear regime. The non-linear regime starts earlier for
smaller objects than for larger ones; smaller objects can form earlier both in
WDM and CDM. We compute and analyze the differential mass function dN/dM for
WDM at redshift z in the Press-Schechter approach. The WDM suppression effect
of small scale structure increases with the redshift z. Our results for dN/dM
are useful to be contrasted with observations, in particular for 4 < z < 12. We
perfom all these studies for the most popular WDM particle physics models.
Contrasting them to observations should point out the precise value of the WDM
particle mass in the keV scale, and help to single out the best WDM particle
physics model (Abridged).


title:
Enhancing Curiosity Using Interactive Simulations Combined with
  Real-Time Formative Assessment Facilitated by Open-Format Questions on Tablet
  Computers

abstract:
  Students' curiosity often seems nearly nonexistent in a lecture setting; we
discuss a variety of possible reasons for this, but it is the instructor who
typically poses questions while only a few students, usually the better ones,
respond.
  As we have developed and implemented the use of InkSurvey to collect
real-time formative assessment, we have discovered that it can serve in an
unanticipated role: to promote curiosity in engineering physics undergraduates.
Curiosity often motivates creative, innovative people. To encourage such
curiosity, we solicit questions submitted real-time via InkSurvey and
pen-enabled mobile devices (Tablet PCs) in response to interactive simulations
(applets) run either before or in class. This provides students with practice
in asking questions, increases metacognition, and serves as a rich springboard
from which to introduce content and/or address misconceptions.
  We describe the procedure for measuring curiosity and results from applying
this method in a junior level electromagnetics engineering physics course. We
conclude that students are indeed more curious than they appear in class, and
students participate even without extrinsic motivation. This method of
enhancing curiosity using interactive simulations coupled with real-time
formative assessment in response to open-format questions could be implemented
in a wide variety of science and engineering courses as well as elsewhere.


title: On the Spectrum of Lattice Massive SU(2) Yang-Mills

abstract:
  On the basis of extended simulations we provide some results concerning the
spectrum of Massive SU(2) Yang-Mills on the lattice. We study the "time"
correlator of local gauge invariant operators integrated over the remaining
three dimensions. The energy gaps are measured in the isospin I=0,1 and
internal spin J=0,1 channels. No correlation is found in the I=1,J=0 channel.
In the I=1, J=1 channel and far from the critical mass value $m_c$ the energy
gap roughly follows the bare value $m$ (vector mesons). In approaching the
critical value $m_c$ at $\beta$ fixed, there is a bifurcation of the energy
gap: one branch follows the value $m$, while the new is much larger and it
shows a more and more dominant weight. This phenomenon might be the sign of two
important features: the long range correlation near the fixed point at $\beta
\to \infty$ implied by the low energy gap and the screening (or confining)
mechanisms across the $m=m_c$ associated to the larger gap. The I=0, J=0,1 gaps
are of the same order of magnitude, typically larger than the I=1, J=1 gap (for
$m>>m_c$). For $m\sim m_c$ both I=0 gaps have a dramatic drop with minima near
the value $m$. This behavior might correspond to the formation of I=0 bound
states both in the J=0 and J=1 channels.


title: Dispersive Light Propagation at Cosmological Distances: Matter Effects

abstract:
  Searches for dispersive effects in the propagation of light at cosmological
distances have been touted as sensitive probes of Lorentz invariance violation
(LIV) and of theories of quantum gravity. Frequency-dependent time lags between
simultaneously emitted pulses of light can signal a modification in the photon
dispersion relation; however, matter engenders the cosmos with a dispersive
index of refraction to similar effect. We construct a theoretical framework for
the analysis of such effects, contrasting these dispersive terms with those
from LIV models. We consider all matter, both luminous and dark. Though the
only known mode of interaction for dark matter (DM) is gravitational, most
models of dark matter also allow for electromagnetic interactions, if only at
the one-loop level in perturbation theory. Generically, the leading order
dispersive effects due to matter scale with photon energy as \omega^{-2} for a
charged DM candidate and \omega^2 for a neutral DM candidate. Terms linear in
\omega can arise in the index of refraction if parity and charge-parity
asymmetries are present at the Lagrangian or system level. Herein, we compute
the index of refraction for a millicharged dark matter candidate at the
one-loop level, a neutral scalar DM candidate introduced by Boehm and Fayet,
and the MSSM's neutralino. For a neutral DM candidate, we determine that matter
effects can compete with LIV effects that depend quadratically on energy
whenever the photon energy is beyond 10^{29} GeV, well beyond the GZK cutoff.
The dispersive matter effects that scale linearly with \omega are model
dependent, and their existence results in circular birefringence.


title: Descent for n-Bundles

abstract:
  Given a Lie group G, one constructs a principal G-bundle on a manifold X by
taking a cover U of X, specifying a transition cocycle on the cover, and
descending the trivialized bundle along the cover. We demonstrate the existence
of an analogous construction for local n-bundles for general n. We establish
analogues for simplicial Lie groups of Moore's results on simplicial groups;
these imply that bundles for strict Lie n-groups arise from local n-bundles.
Our construction leads to simple finite dimensional models of Lie 2-groups such
as String(n).


title: Deriving Proper Uniform Priors for Regression Coefficients, Part II

abstract:
  It is a relatively well-known fact that in problems of Bayesian model
selection improper priors should, in general, be avoided. In this paper we
derive a proper and parsimonious uniform prior for regression coefficients. We
then use this prior to derive the corresponding evidence values of the
regression models under consideration. By way of these evidence values one may
proceed to compute the posterior probabilities of the competing regression
models.


title: Nonperturbative Ambiguities and the Reality of Resurgent Transseries

abstract:
  In a wide range of quantum theoretical settings -- from quantum mechanics to
quantum field theory, from gauge theory to string theory -- singularities in
the complex Borel plane, usually associated to instantons or renormalons,
render perturbation theory ill-defined as they give rise to nonperturbative
ambiguities. These ambiguities are associated to choices of an integration
contour in the resummation of perturbation theory, along (singular) Stokes
directions in the complex Borel plane (rendering perturbative expansions
non-Borel summable along any Stokes line). More recently, it has been shown
that the proper framework to address these issues is that of resurgent analysis
and transseries. In this context, the cancelation of all nonperturbative
ambiguities is shown to be a consequence of choosing the transseries median
resummation as the appropriate family of unambiguous real solutions along the
coupling-constant real axis. While the median resummation is easily implemented
for one-parameter transseries, once one considers more general multi-parameter
transseries the procedure becomes highly dependent upon properly understanding
Stokes transitions in the complex Borel plane. In particular, all Stokes
coefficients must now be known in order to explicitly implement multi-parameter
median resummations. In the cases where quantum-theoretical physical
observables are described by resurgent functions and transseries, the methods
described herein show how one may cancel nonperturbative ambiguities, and
define these observables nonperturbatively starting out from perturbation
theory. Along the way, structural results concerning resurgent transseries are
also obtained.


title:
Study of Center of Mass Energy by Particles Collision in Some Black
  Holes

abstract:
  This paper is devoted to the study of particles collision for two well-known
black holes. We consider particles moving in equatorial plane and calculate
their center of mass energy. Firstly, we explore center of mass energy of a
regular black hole. In this case, acceleration and collision of particles lead
to high center of mass energy which is independent of event horizon and naked
singularity. Secondly, we investigate the center of mass energy of Plebanski
and Demianski black hole (non-extremal) with zero NUT parameter. Here the
center of mass energy depends upon the rotation parameter. We conclude that the
center of mass energy becomes infinitely large for both black holes.


title: Matrix elements of Fourier Integral Operators

abstract:
  This article is concerned with the semi-classical limits of matrix elements
$<F \phi_j, \phi_j>$ of eigenfunctions of the Laplacian $\Delta_g$ of a compact
Riemannian manifold $(M, g)$ with respect to a Fourier integral operator $F$ on
$L^2(M)$. Many results exist for the case where $F$ is a pseudo-differential
operator, but matrix elements of Fourier integral operators involve new
considerations. The limits reflect the extent to which the canonical relation
of $F$ is invariant under the geodesic flow of $(M, g)$. When the canonical
relation is almost nowhere invariant, a density one subsequence of the matrix
elements tends to zero (related results arose first in the study of quantum
ergodic restriction theorems). The limit states are invariant measures on the
canonical relation of $F$ and their invariance properties are explained. The
invariance properties in the case of Hecke operators answers an old question
raised by the author.


title:
Latent Networks Fusion based Model for Event Recommendation in Offline
  Ephemeral Social Networks

abstract:
  With the growing amount of mobile social media, offline ephemeral social
networks (OffESNs) are receiving more and more attentions. Offline ephemeral
social networks (OffESNs) are the networks created ad-hoc at a specific
location for a specific purpose and lasting for short period of time, relying
on mobile social media such as Radio Frequency Identification (RFID) and
Bluetooth devices. The primary purpose of people in the OffESNs is to acquire
and share information via attending prescheduled events. Event Recommendation
over this kind of networks can facilitate attendees on selecting the
prescheduled events and organizers on making resource planning. However,
because of lack of users preference and rating information, as well as explicit
social relations, both rating based traditional recommendation methods and
social-trust based recommendation methods can no longer work well to recommend
events in the OffESNs. To address the challenges such as how to derive users
latent preferences and social relations and how to fuse the latent information
in a unified model, we first construct two heterogeneous interaction social
networks, an event participation network and a physical proximity network.
Then, we use them to derive users latent preferences and latent networks on
social relations, including like-minded peers, co-attendees and friends.
Finally, we propose an LNF (Latent Networks Fusion) model under a pairwise
factor graph to infer event attendance probabilities for recommendation.
Experiments on an RFID-based real conference dataset have demonstrated the
effectiveness of the proposed model compared with typical solutions.


title:
A submillimetre-bright z~3 overdensity behind a z~1 supercluster
  revealed by SCUBA-2 and Herschel

abstract:
  We present a wide-field (30' diameter) 850um SCUBA-2 map of the spectacular
three-component merging supercluster, RCS 231953+00, at z=0.9. The brightest
submillimetre galaxy (SMG) in the field (S_850=12mJy) is within 30" of one of
the cluster cores (RCS 2319-C), and is likely to be a more distant, lensed
galaxy. Interestingly, the wider field around RCS 2319-C reveals a local
overdensity of SMGs, exceeding the average source density by a factor of 4.5,
with a <1 per cent chance of being found in a random field. Utilizing
Herschel-SPIRE observations, we find three of these SMGs have similar
submillimetre colours. We fit their observed 250-850um spectral energy
distributions to estimate their redshift, yielding 2.5<z<3.5, and calculate
prodigious star formation rates (SFRs) ranging from 500-2500 solar masses per
year. We speculate that these galaxies are either lensed SMGs, or signpost a
physical structure at z~3: a 'protocluster' inhabited by young galaxies in a
rapid phase of growth, destined to form the core of a massive galaxy cluster by
z=0.


title:
Measurement of the leptonic asymmetry in ttbar events produced in ppbar
  collisions at sqrt(s)=1.96 TeV

abstract:
  We measure the asymmetry in the charge-weighted rapidity of the lepton in
semileptonic ttbar decays recorded with the CDF II detector using the full
Tevatron Run II sample, corresponding to an integrated luminosity of 9.4/fb. A
parametrization of the asymmetry as a function of the charge-weighted rapidity
is used to correct for the finite acceptance of the detector and recover the
production-level asymmetry. The result of afb(lep) = 0.094 +0.032 -0.029 is to
be compared to the standard model next-to-leading-order prediction of afb(lep)
= 0.038 +-0.003.


title: Highlights from BESIII

abstract:
  We present a selection of recent results from the BESIII collaboration,
including both charmonium and $D$ meson physics. We first discuss the
observation of a charged, charmonium-like state, the $Z_c(3900)$. Conventional
charmonium topics include a search for lepton flavor violation, studies of
$\chi_{cJ} \to \gamma\gamma$ decays, and mass and width determinations for the
$h_c$, $\eta_c(1S)$, and $\eta_c(2S)$. We finish with results on the decay
constant $f_D$ from $D^+ \to \mu^+ \nu$ and on form-factors in $D^0 \to K^- e^+
\nu, \pi^- e^+ \nu$.


title:
The minimization of matrix logarithms - on a fundamental property of the
  unitary polar factor

abstract:
  We show that the unitary factor U in the polar decomposition of a nonsingular
matrix Z = U H is the minimizer for both ||Log(Q^* Z)|| and ||sym (Log(Q^*Z))||
over unitary Q, for any given invertible complex n-times-n matrix Z, for any
unitarily invariant norm and any n. We prove that U is the unique matrix with
this property. As important tools we use a generalized Bernstein trace
inequality and the theory of majorization.


title: Interlacing of zeros of weakly holomorphic modular forms

abstract:
  We prove that the zeros of a family of extremal modular forms interlace,
settling a question of Nozaki. Additionally, we show that the zeros of almost
all forms in a basis for the space of weakly holomorphic modular forms of
weight $k$ for $\SL_2(\mathbb{Z})$ interlace on most of the lower boundary of
the fundamental domain.


title:
Smooth densities of stochastic differential equations forced by
  degenerate stable type noises

abstract:
  Using the Bismut's approach to Malliavin calculus, we introduce a simplified
Malliavin matrix ([11]) for stochastic differential equations (SDEs) force by
degenerate stable like noises. For the degenerate SDEs driven by Wiener noises,
one can derive a Norris type lemma and use it \emph{iteratively} to prove the
smoothness of density functions. Unfortunately, Norris type lemma is very hard
to be iteratively applied to SDEs with stable like noises. In this paper, we
derive a simple inequality as a replacement and use it to show that two
families of degenerate SDEs with stable like noises admit smooth density
functions. One family is the linear SDEs studied by Priola and Zabczyk ([13]),
under some additional assumption we can iteratively use the inequality to get
the smoothness of the density. The other family is the general SDEs with stable
like noises, we can apply this inequality only \emph{one} time and thus derive
that the SDEs admit smooth density if the \emph{first} order Lie brackets span
$\R^d$. The crucial step in this paper is estimating the smallest eigenvalue of
the simplified Malliavin matrix, which only uses some elementary facts of
Poisson processes and undergraduate level ordinary differential equations.


title:
Creation of the inverse population in the $^{229}$Th ground-state
  doublet

abstract:
  A new method for obtaining of inverse population between quadrupole sublevels
of the ground state $5/2^+(0.0)$ and the isomeric state $3/2^+(7.6$ eV) of the
$^{229}$Th nucleus in a dielectric crystal with a large band gap by means of
external source of the VUV radiation is proposed. The method is based on an
efficient depopulation of the upper sublevels of the ground state of $^{229}$Th
by resonant photons from narrowband laser or broader tunable free electron
laser. Sublevels of the isomeric state play the role of intermediate states. In
addition, we have considered a case of excitation of the isomeric state
(without creation of inverse population) by broadband source of light with the
anti-Stokes scattering. The proposed scheme of optical pumping results in (1)
inverse population of nuclear sublevels without using extremely low
temperatures, and (2) shows a new way for the creation of the gamma-ray laser
of optical range at the nuclear transition in $^{229}$Th (a) in crystals with
isovalent substitution of host ions (eg Si$^{4+}$ ions in the SiO$_2$ crystal
replaced by the $^{229}$Th$^{4+}$ ions) and (b) in crystals such as
Na$_2$ThF$_6$, where the substitution is not necessary.


title: Image interpolation using Shearlet based iterative refinement

abstract:
  This paper proposes an image interpolation algorithm exploiting sparse
representation for natural images. It involves three main steps: (a) obtaining
an initial estimate of the high resolution image using linear methods like FIR
filtering, (b) promoting sparsity in a selected dictionary through iterative
thresholding, and (c) extracting high frequency information from the
approximation to refine the initial estimate. For the sparse modeling, a
shearlet dictionary is chosen to yield a multiscale directional representation.
The proposed algorithm is compared to several state-of-the-art methods to
assess its objective as well as subjective performance. Compared to the cubic
spline interpolation method, an average PSNR gain of around 0.8 dB is observed
over a dataset of 200 images.


title:
Momentum dependence in K-edge resonant inelastic x-ray scattering and
  its application to screening dynamics in CE-phase La$_{0.5}$Sr$_{1.5}$MnO$_4$

abstract:
  We present a formula for the calculation of K-edge resonant inelastic x-ray
scattering on transition metal compounds, based on a local interaction between
the valence shell electrons and the $1s$ core hole. Extending a previous
result, we include explicit momentum dependence and a basis with multiple
core-hole sites. We apply this formula to a single-layered charge, orbital and
spin ordered manganite, La$_{0.5}$Sr$_{1.5}$MnO$_4$, and obtain good agreement
with experimental data, in particular with regards to the large variation of
the intensity with momentum. We find that the screening in
La$_{0.5}$Sr$_{1.5}$MnO$_4$ is highly localized around the core-hole site and
demonstrate the potential of K-edge resonant inelastic x-ray scattering as a
probe of screening dynamics in materials.


title:
Embedding a carbon nanotube across the diameter of a solid state
  nanopore

abstract:
  A fabrication method for positioning and embedding a single-walled carbon
nanotube (SWNT) across the diameter of a solid state nanopore is presented.
Chemical vapor deposition (CVD) is used to grow SWNTs over arrays of focused
ion beam (FIB) milled pores in a thin silicon nitride membrane. This typically
yields at least one pore whose diameter is centrally crossed by a SWNT. The
final diameter of the FIB pore is adjusted to create a nanopore of any desired
diameter by atomic layer deposition (ALD), simultaneously embedding and
insulating the SWNT everywhere but in the region that crosses the diameter of
the final nanopore, where it remains pristine and bare. This
nanotube-articulated nanopore is an important step towards the realization of a
new type of detector for biomolecule sensing and electronic characterization,
including DNA sequencing.

categories: physics.bio-ph cond-mat.mes-hall cond-mat.mtrl-sci cond-mat.soft physics.ins-det


title: Method of Running Sines: Modeling Variability in Long-Period Variables

abstract:
  We review one of complementary methods for time series analysis - the method
of "Running Sines". "Crash tests" of the method include signals with a large
period variation and with a large trend. The method is most effective for
"nearly periodic" signals, which exhibit "wavy shape" with a "cycle length"
varying within few dozen per cent (i.e. oscillations of low coherence). This is
a typical case for brightness variations of long-period pulsating variables and
resembles QPO (Quasi-Periodic Oscillations) and TPO (Transient Periodic
Oscillations) in interacting binary stars - cataclysmic variables, symbiotic
variables, low-mass X-Ray binaries etc. General theory of "running
approximations" was described by Andronov (1997A &AS..125..207A), one of
realizations of which is the method of "running sines". The method is related
to Morlet-type wavelet analysis improved for irregularly spaced data (Andronov,
1998KFNT...14..490A, 1999sss..conf...57A), as well as to a classical "running
mean" (="moving average"). The method is illustrated by an application to a
model signal with strongly variable period, as well as to a semi-regular
variable AF Cyg. Some other stars studied with this method are discussed, e.g.
RU And (switching between "Mira-type" large amplitude oscillations and time
intervals of "constancy"), intermediate polars MU Cam (1RXS J062518.2+733433)
and BG CMi, magnetic dwarf nova DO Dra, symbiotic stars UV Aur and V1329 Cyg.


title: Nevanlinna-Pick spaces with hyponormal multiplication operators

abstract:
  We show that the Hardy space on the unit disk is the only non-trivial
irreducible reproducing kernel Hilbert space which satisfies the complete
Nevanlinna-Pick property and hyponormality of all multiplication operators.


title:
Olivine or Impact Melt: Nature of the "Orange" Material on Vesta from
  Dawn

abstract:
  NASA's Dawn mission observed a great variety of colored terrains on asteroid
(4) Vesta during its survey with the Framing Camera (FC). Here we present a
detailed study of the orange material on Vesta, which was first observed in
color ratio images obtained by the FC and presents a red spectral slope. The
orange material deposits can be classified into three types, a) diffuse ejecta
deposited by recent medium-size impact craters (such as Oppia), b) lobate
patches with well-defined edges, and c) ejecta rays from fresh-looking impact
craters. The location of the orange diffuse ejecta from Oppia corresponds to
the olivine spot nicknamed "Leslie feature" first identified by Gaffey (1997)
from ground-based spectral observations. The distribution of the orange
material in the FC mosaic is concentrated on the equatorial region and almost
exclusively outside the Rheasilvia basin. Our in-depth analysis of the
composition of this material uses complementary observations from FC, the
visible and infrared spectrometer (VIR), and the Gamma Ray and Neutron Detector
(GRaND). Combining the interpretations from the topography, geomorphology,
color and spectral parameters, and elemental abundances, the most probable
analog for the orange material on Vesta is impact melt.

categories: astro-ph.EP astro-ph.IM physics.geo-ph physics.space-ph


title: Mixtures of functionalized colloids on substrates

abstract:
  Patchy particles are a class of colloids with functionalized surfaces.
Through surface functionalization, the strength and directionality of the
colloidal interactions are tunable allowing control over coordination of the
particle. Exquisite equilibrium phase diagrams of mixtures of coordination two
and three have been reported. However, the kinetics of self-organization and
the feasibility of the predicted structures are still largely unexplored. Here,
we study the irreversible aggregation of these mixtures on a substrate, for
different fractions of two-patch particles. Two mechanisms of mass transport
are compared: diffusion and advection. In the diffusive case, an optimal
fraction is found that maximizes the density of the aggregate. By contrast, for
advective transport, the density decreases monotonically with the fraction of
two-patch colloids, in line with the behavior of the liquid density on the
spinodal of the equilibrium phase diagram.


title:
Cooperation in changing environments: Irreversibility in the transition
  to cooperation in networks

abstract:
  In the framework of the evolutionary dynamics of the Prisoner's Dilemma game
on complex networks, we investigate the possibility that the average level of
cooperation shows hysteresis under quasi-static variations of a model parameter
(the "temptation to defect"). Under the "discrete replicator" strategy updating
rule, for both Erdos-Renyi and Barabasi-Albert graphs we observe cooperation
hysteresis cycles provided one reaches tipping point values of the parameter;
otherwise, perfect reversibility is obtained. The selective fixation of
cooperation at certain nodes and its organization in cooperator clusters, that
are surrounded by fluctuating strategists, allows the rationalization of the
"lagging behind" behavior observed.


title: Weighted Local Estimates for Singular Integral Operators

abstract:
  A local median decomposition is used to prove that a weighted local mean of a
function is controlled by a weighted local mean of its local sharp maximal
function. Together with (a local version of) the estimate
$M^{\sharp}_{0,s}(Tf)(x) \le c\,Mf(x)$ for Calder\'{o}n-Zygmund singular
integral operators, this allows us to express the local weighted integral
control of $Tf$ by $Mf$. Similar estimates hold for $T$ replaced by singular
integrals with kernels satisfying H\"{o}rmander-type conditions or integral
operators with homogeneous kernels, and $M$ replaced by an appropriate maximal
function $M_T$. Using sharper bounds in the local median decomposition we prove
two-weight, $L^p_v$-$L^q_w$ estimates for singular integral operators for
$1<p\le q<\infty$. In all cases, the results include weights that are not
necessarily $A_{\infty}$. The local nature of these estimates leads to results
involving weighted generalized Orlicz-Campanato and Orlicz-Morrey spaces.


title: Normal form for Ritt's Second Theorem

abstract:
  Ritt's Second Theorem deals with composition collisions g o h = g* o h* of
univariate polynomials over a field, where deg g = deg h*. Joseph Fels Ritt
(1922) presented two types of such decompositions. His main result here is that
these comprise all possibilities, up to some linear transformations. Because of
these transformations, the result has been called "difficult to use". We
present a normal form for Ritt's Second Theorem, which is hopefully "easy to
use", and clarify the relation between the two types of examples. This yields
an exact count of the number of such collisions in the "tame case", where the
characteristic of the (finite) ground field does not divide the degree of the
composed polynomial.


title: Bayesian inference for Mat\'ern repulsive processes

abstract:
  In many applications involving point pattern data, the Poisson process
assumption is unrealistic, with the data exhibiting a more regular spread. Such
a repulsion between events is exhibited by trees for example, because of
competition for light and nutrients. Other examples include the locations of
biological cells and cities, and the times of neuronal spikes. Given the many
applications of repulsive point processes, there is a surprisingly limited
literature developing flexible, realistic and interpretable models, as well as
efficient inferential methods. We address this gap by developing a modelling
framework around the Mat\'ern type-III repulsive process. We consider a number
of extensions of the original Mat\'ern type-III process for both the
homogeneous and inhomogeneous cases. We also derive the probability density of
this generalized Mat\'ern process. This allows us to characterize the posterior
distribution of the various latent variables, and leads to a novel and
efficient Markov chain Monte Carlo algorithm. We apply our ideas to datasets
involving the spatial locations of trees, nerve fiber cells and Greyhound bus
stations.


title:
Products of 2X2 matrices related to non autonomous Fibonacci difference
  equations

abstract:
  A technique to compute arbitrary products of a class of Fibonacci $2\times2$
square matrices is proved in this work. General explicit solutions for non
autonomous Fibonacci difference equations are obtained from these products. In
the periodic non autonomous Fibonacci difference equations the monodromy
matrix, the Floquet multipliers and the Binet's formulas are obtained. In the
periodic case explicit solutions are obtained and the solutions are analyzed.


title: The Vectorial $\lambda$-Calculus

abstract:
  We describe a type system for the linear-algebraic $\lambda$-calculus. The
type system accounts for the linear-algebraic aspects of this extension of
$\lambda$-calculus: it is able to statically describe the linear combinations
of terms that will be obtained when reducing the programs. This gives rise to
an original type theory where types, in the same way as terms, can be
superposed into linear combinations. We prove that the resulting typed
$\lambda$-calculus is strongly normalising and features weak subject reduction.
Finally, we show how to naturally encode matrices and vectors in this typed
calculus.


title:
Numerical simulations of multiple scattering of the $f-$mode by flux
  tubes

abstract:
  We use numerial simulations to study the absorption and phase shift of
surface-gravity waves caused by groups of magnetic flux tubes. The dependence
of the scattering coefficients with the distance between the tubes and their
positions is analyzed for several cases with two or three flux tubes embedded
in a quiet Sun atmosphere. The results are compared with those obtained
neglecting completely or partially multiple scattering effects. We show that
multiple scattering has a significant impact on the absorption measurements and
tends to reduce the phase shift. We also consider more general cases of
ensembles of randomly distributed flux tubes, and we have evaluated the effects
on the scattering measurements of changing the number of tubes included in the
bundle and the average distance between flux tubes. We find that for the
longest wavelength incoming waves multiple scattering enhances the absorption,
and its efficiency increases with the number of flux tubes and the reduction of
the distance between them.


title: Residual symmetries and B\"acklund transformations

abstract:
  It is proved that for a given truncated Painlev\'e expansion of an arbitrary
nonlinear Painlev\'e integrable system, the residue with respect to the
singularity manifold is a nonlocal symmetry. The residual symmetries can be
localized to Lie point symmetries after introducing suitable prolonged systems.
The finite transformations of the residual symmetries are equivalent to the
second type of Darboux-B\"acklund transformations. The once B\"acklund
transformations related to the residual symmetries are same for many integrable
systems including the Korteweg-de Vries, Kadomtsev-Petviashvili, Boussinesq,
Sawada-Kortera and Kaup-Kupershmidt equations. For the Korteweg-de Vries
equation, the $n^{th}$ Darboux transformations can also be obtained from the
Lie point symmetry approach via the localization of the residual symmetries.


title: A=U for Locally Acyclic Cluster Algebras

abstract:
  This note presents a self-contained proof that acyclic and locally acyclic
cluster algebras coincide with their upper cluster algebras.


title:
Conformal-Frame (In)dependence of Cosmological Observations in
  Scalar-Tensor Theory

abstract:
  We provide the correspondence between the variables in the Jordan frame and
those in the Einstein frame in scalar-tensor gravity and consider the
frame-(in)dependence of the cosmological observables. In particular, we show
that the cosmological observables/relations (redshift, luminosity distance,
temperature anisotropies) are frame-independent. We also study the
frame-dependence of curvature perturbations and find that the curvature
perturbations are conformal invariant if the perturbation is adiabatic and the
entropy perturbation between matter and the Brans-Dicke scalar is vanishing.
The relation among various definitions of curvature perturbations in the both
frames is also discussed, and the condition for the equivalence is clarified.


title:
Pseudospin symmetry in supersymmetric quantum mechanics: II. Spin-orbit
  effects

abstract:
  Following a previous paper [Haozhao Liang \textit{et al.}, Phys. Rev. C
\textbf{87}, 014334 (2013)], we discuss the spin-orbit effects on the
pseudospin symmetry (PSS) within the framework of supersymmetric quantum
mechanics. By using the perturbation theory, we demonstrate that the
perturbative nature of PSS maintains when a substantial spin-orbit potential is
included. With the explicit PSS-breaking potential, the spin-orbit effects on
the pseudospin-orbit splittings are investigated in a quantitative way.


title:
Performance Limits and Practical Decoding of Interleaved Reed-Solomon
  Polar Concatenated Codes

abstract:
  A scheme for concatenating the recently invented polar codes with non-binary
MDS codes, as Reed-Solomon codes, is considered. By concatenating binary polar
codes with interleaved Reed-Solomon codes, we prove that the proposed
concatenation scheme captures the capacity-achieving property of polar codes,
while having a significantly better error-decay rate. We show that for any
$\epsilon > 0$, and total frame length $N$, the parameters of the scheme can be
set such that the frame error probability is less than $2^{-N^{1-\epsilon}}$,
while the scheme is still capacity achieving. This improves upon
$2^{-N^{0.5-\epsilon}}$, the frame error probability of Arikan's polar codes.
The proposed concatenated polar codes and Arikan's polar codes are also
compared for transmission over channels with erasure bursts. We provide a
sufficient condition on the length of erasure burst which guarantees failure of
the polar decoder. On the other hand, it is shown that the parameters of the
concatenated polar code can be set in such a way that the capacity-achieving
properties of polar codes are preserved. We also propose decoding algorithms
for concatenated polar codes, which significantly improve the error-rate
performance at finite block lengths while preserving the low decoding
complexity.


title:
A Beam Driven Plasma-Wakefield Linear Collider: From Higgs Factory to
  Multi-TeV

abstract:
  Plasma wakefield acceleration (PWFA) holds much promise for advancing the
energy frontier because it can potentially provide a 1000-fold or more increase
in acceleration gradient with excellent power efficiency in respect with
standard technologies. Most of the advances in beam-driven plasma wakefield
acceleration were obtained by a UCLA/USC/SLAC collaboration working at the SLAC
FFTB[ ]. These experiments have shown that plasmas can accelerate and focus
both electron and positron high energy beams, and an accelerating gradient in
excess of 50 GeV/m can be sustained in an 85 cm-long plasma. The FFTB
experiments were essentially proof-of-principle experiments that showed the
great potential of plasma accelerators.
  The FACET[ ] test facility at SLAC will in the period 2012-2016 further study
several issues that are directly related to the applicability of PWFA to a
high-energy collider, in particular two-beam acceleration where the witness
beam experiences high beam loading (required for high efficiency), small energy
spread and small emittance dilution (required to achieve luminosity).
  The PWFA-LC concept presented in this document is an attempt to find the best
design that takes advantage of the PWFA, identify the critical parameters to be
achieved and eventually the necessary R&D to address their feasibility. It best
benefits from the extensive R&D that has been performed for conventional rf
linear colliders during the last twenty years, especially ILC[ ] and CLIC[ ],
with a potential for a comparably lower power consumption and cost.


title:
Frequency agile microwave photonic notch filter with anomalously-high
  stopband rejection

abstract:
  We report a novel class microwave photonic (MWP) notch filter with a very
narrow isolation bandwidth (10 MHz), an ultrahigh stopband rejection (> 60 dB),
a wide frequency tuning (1-30 GHz), and flexible bandwidth reconfigurability
(10-65 MHz). This record performance is enabled by a new concept of sidebands
amplitude and phase controls using an electro-optic modulator and an optical
filter. This new concept enables energy efficient operation in active MWP notch
filters, and opens up the pathway to enable low-power nanophotonic devices as
high performance RF filters.


title: Empirical entropy, minimax regret and minimax risk

abstract:
  We consider the random design regression model with square loss. We propose a
method that aggregates empirical minimizers (ERM) over appropriately chosen
random subsets and reduces to ERM in the extreme case, and we establish sharp
oracle inequalities for its risk. We show that, under the $\varepsilon^{-p}$
growth of the empirical $\varepsilon$-entropy, the excess risk of the proposed
method attains the rate $n^{-2/(2+p)}$ for $p\in(0,2)$ and $n^{-1/p}$ for $p>2$
where $n$ is the sample size. Furthermore, for $p\in(0,2)$, the excess risk
rate matches the behavior of the minimax risk of function estimation in
regression problems under the well-specified model. This yields a conclusion
that the rates of statistical estimation in well-specified models (minimax
risk) and in misspecified models (minimax regret) are equivalent in the regime
$p\in(0,2)$. In other words, for $p\in(0,2)$ the problem of statistical
learning enjoys the same minimax rate as the problem of statistical estimation.
On the contrary, for $p>2$ we show that the rates of the minimax regret are, in
general, slower than for the minimax risk. Our oracle inequalities also imply
the $v\log(n/v)/n$ rates for Vapnik-Chervonenkis type classes of dimension $v$
without the usual convexity assumption on the class; we show that these rates
are optimal. Finally, for a slightly modified method, we derive a bound on the
excess risk of $s$-sparse convex aggregation improving that of Lounici [Math.
Methods Statist. 16 (2007) 246-259] and providing the optimal rate.


title:
Log minimal model program for the moduli space of stable curves: The
  second flip

abstract:
  We prove an existence theorem for good moduli spaces, and use it to construct
the second flip in the log minimal model program for the moduli space of stable
curves. In fact, our methods give a uniform, self-contained construction of the
first three steps of the log minimal model program for the moduli spaces of
stable pointed curves.


title: Atom-molecule conversion system subject to phase noises

abstract:
  The dynamics of atom-molecule conversion system subject to dephasing noises
is studied in this paper. With the dephasing master equation and the mean-field
theory, we drive a Bloch equation for the system, this equation is compared
with the Bloch equation derived by the Bogoliubov-Born-Green-Kirkwood-Yvon
(BBGKY) hierarchy truncation approach. Fixed points of the system are
calculated by solving both the Bloch equations and the master equation,
comparison between these two calculations suggests that while in a short time
the mean-field theory is a good approximation for the atom-molecule conversion
system, a high order hierarchy truncation approach is necessary for the system
in a long time scale. Although the MFT can not predict correctly the fixed
points, its prediction on the stability of the fixed points are consistent with
the BBGKY theory for a wide range of parameters.


title: Multimodal Approach for Video Surveillance Indexing and Retrieval

abstract:
  In this paper, we present an overview of a multimodal system to indexing and
searching video sequence by the content that has been developed within the
REGIMVid project. A large part of our system has been developed as part of
TRECVideo evaluation. The MAVSIR platform provides High-level feature
extraction from audio-visual content and concept/event-based video retrieval.
We illustrate the architecture of the system as well as provide an overview of
the descriptors supported to date. Then we demonstrate the usefulness of the
toolbox in the context of feature extraction, concepts/events learning and
retrieval in large collections of video surveillance dataset. The results are
encouraging as we are able to get good results on several event categories,
while for all events we have gained valuable insights and experience.


title: Measurement of the Mass of the D0 Meson

abstract:
  We report a measurement of the D0 meson mass using the decay chain D*(2010)+
-> D0 pi+ with D0 -> K- K- K+ pi+. The data were recorded with the BaBar
detector at center-of-mass energies at and near the Y(4S) resonance, and
correspond to an integrated luminosity of approximately 477 1/fb. We obtain
m(D0) = (1864.841 +- 0.048 +- 0.063) MeV, where the quoted errors are
statistical and systematic, respectively. The uncertainty of this measurement
is half that of the best previous measurement.


title: Two neutron decay from the $2_1^+$ state of $^6$He

abstract:
  Decay mode of the $2_1^+$ resonant state of $^6$He populated by the $^6$He
breakup reaction by $^{12}$C at 240 MeV/nucleon is investigated. The
continuum-discretized coupled-channels method is adopted to describe the
formation of the $2_1^+$ state, whereas its decay is described by the
complex-scaled solutions of the Lippmann-Schwinger equation. From analysis of
invariant mass spectra with respect to the $\alpha$-$n$ and $n$-$n$ subsystems,
coexistence of two decay modes is found. One is the simultaneous decay of two
neutrons correlating with each other and the other is the emission of two
neutrons to the opposite directions. The latter is found to be free from the
final state interaction and suggests existence of a di-neutron in the $2_1^+$
state of $^6$He.


title:
Terahertz dielectric response and coupled dynamics of ferroelectrics and
  multiferroics from effective Hamiltonian simulations

abstract:
  Ferroelectric and multiferroic materials form an important class of
functional materials. Over the last twenty years, first-principles-based
effective Hamiltonian approaches have been successfully developed to simulate
these materials. In recent years, effective Hamiltonian approaches were further
combined with molecular dynamics methods to investigate terahertz dynamical
properties of various perovskites. With this combination, a variety of
ferroelectric and multiferroic materials, including BaTiO_{3}, Ba(Sr,Ti)O_{3},
Pb(Zr,Ti)O_{3}, BiFeO_{3}, and SrTiO_{3} bulks and films have been simulated,
which led to the understanding of complex phenomena and discovery of novel
effects. In this review, we first provide technical details about effective
Hamiltonians and molecular dynamics simulation. Then, we present applications
of the combination of these two techniques to different perovskites. Finally,
we also briefly discuss possible future directions of this approach.


title: Dynamic evolution of cross-correlations in the Chinese stock market

abstract:
  We study the dynamic evolution of cross-correlations in the Chinese stock
market mainly based on the random matrix theory (RMT). The correlation matrices
constructed from the return series of 367 A-share stocks traded on the Shanghai
Stock Exchange from January 4, 1999 to December 30, 2011 are calculated over a
moving window with a size of 400 days. The evolutions of the statistical
properties of the correlation coefficients, eigenvalues, and eigenvectors of
the correlation matrices are carefully analyzed. We find that the stock
correlations are significantly increased in the periods of two market crashes
in 2001 and 2008, during which only five eigenvalues significantly deviate from
the random correlation matrix, and the systemic risk is higher in these
volatile periods than calm periods. By investigating the significant
contributors of the deviating eigenvectors in different moving windows, we
observe a dynamic evolution behavior in business sectors such as IT,
electronics, and real estate, which lead the rise (drop) before (after) the
crashes.


title:
The Slightly Supercritical Euler Equations: Smooth Solutions and Vortex
  Patches

abstract:
  We investiage the (slightly) super-critical 2-D Euler equations. The paper
consists of two parts. In the first part we prove well-posedness in $C^s$
spaces for all $s>0.$ We also give growth estimates for the $C^s$ norms of the
vorticity for $0< s \leq 1.$ In the second part we prove global regularity for
the vortex patch problem in the super-critical regime.This paper extends the
results of Chae, Constantin, and Wu where they prove well-posedness for the
so-called LogLog-Euler equation. We also extend the classical results of Chemin
and Bertozzi-Constantin on the vortex patch problem to the slightly
supercritical case. The supercritical vortex patch problem introduces several
extra difficulties which are overcome via delicate estimates which take
advantage of the extra tangential regularity of the vortex patches. Both
problems we study are done in the setting of the whole space.


title:
Modeling the Migration of Neptune and the Corresponding Resonant
  Captures

abstract:
  Due to the angular momentum exchange with planetesimals, Neptune might have
migrated outward to the current position, and captured many Kuiper belt objects
(KBOs) into resonances. We set up a semi-analytic model to simulate the outward
migration of Neptune, and the processes of resonant captures. Our model can
naturally explain Neptune's currently observed semi-major axis and
eccentricity. The results show that the current population ratio between 3:2
and 2:1 is mainly due to the original density distribution of KBOs, which might
be related to drag-induced inward migrations of proto-KBOs.


title:
Proceedings of the 13th Workshop on Algorithms in Bioinformatics
  (WABI2013)

abstract:
  These are the proceedings of the 13th Workshop on Algorithms in
Bioinformatics, WABI2013, which was held September 2-4 2013 in Sophia
Antipolis, France. All manuscripts were peer reviewed by the WABI2013 program
committee and external reviewers.


title: COINs change leaders - Lessons Learned from a Distributed Course

abstract:
  In this paper we analyze the communication network of 50 students from five
universities in three countries participating in a joint course on
Collaborative Innovation Networks (COINs). Students formed ten teams.
Interaction variables calculated from the e-mail archive of individual team
members predict the level of creativity of the team. Oscillating leadership,
where members switch between central and peripheral roles is the best predictor
of creativity, it is complemented by the variance in the amount of sending or
receiving information, and by answering quickly, and positive language. We
verify our automatically generated creativity metrics with interviews.


title:
Azimuthal asymmetries in semi-inclusive DIS with polarized beam and/or
  target and their nuclear dependences

abstract:
  Using the formalism obtained from collinear expansion, we calculate the
differential cross section and azimuthal asymmetries in semi-inclusive deeply
inelastic lepton-nucleon (nucleus) scattering process $e^-+N (A) \to e^-+q+X$
with both polarized beam and polarized target up to twist-3. We derive the
azimuthal asymmetries in terms of twist-3 parton correlation functions. We
simplify the results by using the QCD equation of motion that leads to a set of
relationships between different twist-3 functions. We further study the nuclear
dependence of azimuthal asymmetries and show that they have similar suppression
factors as those in the unpolarized reactions.


title: Coolhunting for the World's Thought Leaders

abstract:
  Which thinkers are we guided by? A novel "Thought Leader Map" shows the
select group of people with real influence who are setting the trends in the
market for ideas. The influencers in philosophy, sociology, economics, and the
"hard sciences" have been identified by a Delphi process, asking 50 thought
leaders to name their peers. The importance of the influencers is calculated by
constructing a co-occurrence network in the Blogosphere. Our main insight is
that the era of the great authorities seems to be over. Major thought leaders
are rare - the picture is composed of many specialists.


title:
Inequivalence of skew Hadamard difference sets and triple intersection
  numbers modulo a prime

abstract:
  Recently, Feng and Xiang \cite{FX113} found a new construction of skew
Hadamard difference sets in elementary abelian groups. In this paper, we
introduce a new invariant for equivalence of skew Hadamard difference sets,
namely triple intersection numbers modulo a prime, and discuss inequivalence
between Feng-Xiang skew Hadamard difference sets and the Paley difference sets.
As a consequence, we show that their construction produces infinitely many skew
Hadamard difference sets inequivalent to the Paley difference sets.


title:
Increasing Knowledge Worker Efficiency through a "Virtual Mirror" of the
  Social Network

abstract:
  In this paper we introduce a case study describing the combination of manual
survey-based and e-mail-based social network analysis. The goal of the project
was to increase collaboration efficiency in a team of consultants of a major
high tech manufacturer. By analyzing the social network of a team of 42
consultants and comparing it with their utilization as the dependent variable,
their efficiency in working together was improved in various way by bridging
structure holes and eliminating bottlenecks, reducing stress for overburdened
individuals, connecting isolated individuals and identifying the best network
structures for high utilization and increased job satisfaction.


title:
New Approach to Cosmological Fluctuation using the Background Field
  Method and CMB Power Spectrum

abstract:
  A new field theory formulation is presented for the analysis of the CMB power
spectrum distribution in the cosmology. The background-field formalism is fully
used. Stimulated by the recent idea of the {\it emergent} gravity, the
gravitational (metric) field $g_\mn$ is not taken as the quantum-field, but as
the background field. The statistical fluctuation effect of the metric field is
taken into account by the path (hyper-surface)-integral over the space-time.
Using a simple scalar model on the curved (dS$_4$) space-time, we explain the
above things with the following additional points: 1) Clear separate treatment
of the classical effect, the statistical effect and the quantum effect; 2) The
cosmological fluctuation comes not from the 'quantum' gravity but from the
unkown 'microscopic' movement; 3) IR parameter ($\ell$) is introduced for the
time axis as the periodicity. Time reversal(Z$_2$)-symmetry is introduced in
order to treat the problem separately with respect to the Z$_2$ parity. This
procedure much helps both UV and IR regularization to work well.


title:
Predicting Client Satisfaction through (E-Mail) Network Analysis: The
  Communication Score Card

abstract:
  This study seeks to better understand the network characteristics of client
support teams by analyzing the teams' e-mail communication networks and
comparing it to client organization's satisfaction. In collaboration with a
large service provider we studied the impact of network properties on the
satisfaction of client organizations. In particular, we found that social
network metrics correlate with client satisfaction as measured by Net Promoter
Score (NPS). A Communication Score Card is suggested as a dashboard to
continuously measure client satisfaction, illustrating that data-driven
analysis might help improving service providers' service quality management.


title:
Nonautonomous control of stable and unstable manifolds in
  two-dimensional flows

abstract:
  We outline a method for controlling the location of stable and unstable
manifolds in the following sense. From a known location of the stable and
unstable manifolds in a steady two-dimensional flow, the primary segments of
the manifolds are to be moved to a user-specified time-varying location which
is near the steady location. We determine the nonautonomous perturbation to the
vector field required to achieve this control, and give a theoretical bound for
the error in the manifolds resulting from applying this control. The efficacy
of the control strategy is illustrated via a numerical example.


title: WikiPulse - A News-Portal Based on Wikipedia

abstract:
  More and more user-generated content is complementing conventional
journalism. While we don't think that CNN or New York Times and its
professional journalists will disappear anytime soon, formidable competition is
emerging through humble Wikipedia editors. In earlier work (Becker 2012), we
found that entertainment and sports news appeared on average about two hours
earlier on Wikipedia than on CNN and Reuters online. In this project we build a
news-reader that automatically identifies late-breaking news among the most
recent Wikipedia articles and then displays it on a dedicated Web site.


title:
Reentrant topological transitions with Majorana end states in 1D
  superconductors by lattice modulation

abstract:
  The possibility to observe and manipulate Majorana fermions as end states of
one-dimensional topological superconductors has been actively discussed
recently. In a quantum wire with strong spin-orbit coupling placed in proximity
to a bulk superconductor, a topological superconductor has been expected to be
realized when the band energy is split by the application of a magnetic field.
When a periodic lattice modulation is applied multiple topological
superconductor phases appear in the phase diagram. Some of them occur for
higher filling factors compared to the case without the modulation. We study
the effects of phase jumps and argue that the topologically nontrivial state of
the whole system is retained even if they are present. We also study the effect
of the spatial modulation in the hopping parameter.


title:
Role and Discipline Relationships in a Transdisciplinary Biomedical
  Team: Structuration, Values Override and Context Scaffolding

abstract:
  Though accepted that "team science" is needed to tackle and conquer the
health problems that are plaguing our society significant empirical evidence of
team mechanisms and functional dynamics is still lacking in abundance. Through
grounded methods the relationship between scientific disciplines and team roles
was observed in a United States National Institutes of Health-funded (NIH)
research consortium. Interviews and the Organizational Culture Assessment
Instrument (OCAI) were employed.. Findings show strong role and discipline
idiosyncrasies that when viewed separately provide different insights into team
functioning and change receptivity. When considered simultaneously,
value-latent characteristics emerged showing self-perceived contributions to
the team. This micro/meso analysis suggests that individual participation in
team level interactions can inform the structuration of roles and disciplines
in an attempt to tackle macro level problems.


title:
Almost sure well-posedness for the periodic 3D quintic nonlinear
  Schr\"odinger equation below the energy space

abstract:
  In this paper we prove an almost sure local well-posedness result for the
periodic 3D quintic nonlinear Schr\"odinger equation in the supercritical
regime, that is below the critical space $H^1(\mathbb T^3)$.


title: Dependence of spin torque diode voltage on applied field direction

abstract:
  The optimum condition of an applied field direction to maximize spin torque
diode voltage was theoretically derived for a magnetic tunnel junction with a
perpendicularly magnetized free layer and an in-plane magnetized pinned layer.
We found that the diode voltage for a relatively small applied field is
maximized when the projection of the applied field to the film-plane is
parallel or anti-parallel to the magnetization of the pinned layer. However, by
increasing the applied field magnitude, the optimum applied field direction
shifts from the parallel or anti-parallel direction. These analytical
predictions were confirmed by numerical simulations.


title: Status of Matter-Gravity Couplings in the SME

abstract:
  Constraints on Lorentz violation in matter-gravity couplings are summarized
along with existing proposals to obtain sensitivities that exceed current
limits by up to 11 orders of magnitude.


title: Differentiable mappings between spaces of sections

abstract:
  In this work, various versions of the so-called Omega-Lemma are provided,
which ensure differentiability properties of pushforwrds between spaces of
C^r-sections (or compactly supported C^r-sections) in vector bundles over
finite-dimensional base manifolds whose fibres are (possibly
infinite-dimensional) locally convex spaces.
  Applications are given, including the proof of continuity for some natural
module multiplications on spaces of sections and the construction of certain
infinite-dimensional Lie groups of Lie group-valued maps.


title:
Electron temperature dependence of the electron-phonon coupling strength
  in double-wall carbon nanotubes

abstract:
  We applied Time-Resolved Two-Photon Photoemission spectroscopy to probe the
electron- phonon (e-ph) coupling strength in double-wall carbon nanotubes. The
e-ph energy transfer rate G(Te,Tl) from the electronic system to the lattice
depends linearly on the electron (Te) and lattice (Tl) temperatures for
Te>{\Theta}Debye. Moreover, we numerically solved the Two-Temperature Model. We
found: (i) a Te decay with a 3.5 ps time constant and no significant change in
Tl; (ii) an e-ph coupling factor of 2x10^16 W/m3; (iii) a mass-enhancement
parameter, {\lambda}, of (5.4=+/- 0.9)x10e-4; and (iv) a decay time of the
electron energy density to the lattice of 1.34+/-0.85 ps.


title: Anytime computation algorithms for approach-evasion differential games

abstract:
  This paper studies a class of approach-evasion differential games, in which
one player aims to steer the state of a dynamic system to the given target set
in minimum time, while avoiding some set of disallowed states, and the other
player desires to achieve the opposite. We propose a class of novel anytime
computation algorithms, analyze their convergence properties and verify their
performance via a number of numerical simulations. Our algorithms significantly
outperform the multi-grid method for the approach-evasion differential games
both theoretically and numerically. Our technical approach leverages
incremental sampling in robotic motion planning and viability theory.


title: Designing a Pattern Language For Surviving Earthquakes

abstract:
  In this paper, we proposed the Survival Language, a pattern language to
support survival when a catastrophic earthquake occurs. This proposal comes
from the problem that the tragedies of earthquakes are repeated, because
knowledge and wisdom on how to prepare for an earthquake and what to do during
an earthquake have not been passed down sufficiently. This paper presented the
four patterns of the Survival Language: "Daily Use of Reserves," "Life over
Furniture," "Evacuation Initiator," and "Kick Signal." In addition, we
described that the Survival Language is created and used by collaborations
because a pattern language has been a tool for collaboration since it was
presented by Christopher Alexander.


title:
The Emergence of Political Discourse on Digital Networks: The Case of
  the Occupy Movement

abstract:
  How does political discourse spread in digital networks? Can we empirically
test if certain conceptual frames of social movements have a correlate on their
online discussion networks? Through an analysis of the Twitter data from the
Occupy movement, this paper describes the formation of political discourse over
time. Building on a previous set of concepts - derived from theoretical
discussions about the movement and its roots - we analyse the data to observe
when those concepts start to appear within the networks, who are those Twitter
users responsible for them, and what are the patterns through which those
concepts spread. Preliminary evidence shows that, although there are some signs
of opportunistic behaviour among activists, most of them are central nodes from
the onset of the network, and shape the discussions across time. These central
activists do not only start the conversations around given frames, but also
sustain over time and become key members of the network. From here, we aim to
provide a thorough account of the "travel" of political discourse, and the
correlate of online conversational networks with theoretical accounts of the
movement.


title: Linear Stability Analysis of a Hot Plasma in a Solid Torus

abstract:
  This paper is a first step toward understanding the effect of toroidal
geometry on the rigorous stability theory of plasmas. We consider a
collisionless plasma inside a torus, modeled by the relativistic Vlasov-Maxwell
system. The surface of the torus is perfectly conducting and it reflects the
particles specularly. We provide sharp criteria for the stability of equilibria
under the assumption that the particle distributions and the electromagnetic
fields depend only on the cross-sectional variables of the torus.


title: Pattern Languages as Media for the Creative Society

abstract:
  This paper proposes new languages for basic skills in the Creative Society,
where people create their own goods, tools, concepts, knowledge, and mechanisms
with their own hands: the skills of learning, presentation, and collaboration.
These languages are written as a pattern language, which is a way of describing
the tacit practical knowledge. In this paper, a new type of pattern languages
are proposed as "Pattern Languages 3.0" and three examples are introduced:
Learning Patterns, Collaboration Patterns, and Presentation Patterns. By
analyzing the functions with the social systems theory and the creative systems
theory, pattern languages are considered as communication media and discovery
media.