title: 3D Simulation for Robot Arm Control with Deep Q-Learning

abstract:
  Recent trends in robot arm control have seen a shift towards end-to-end
solutions, using deep reinforcement learning to learn a controller directly
from raw sensor data, rather than relying on a hand-crafted, modular pipeline.
However, the high dimensionality of the state space often means that it is
impractical to generate sufficient training data with real-world experiments.
As an alternative solution, we propose to learn a robot controller in
simulation, with the potential of then transferring this to a real robot.
Building upon the recent success of deep Q-networks, we present an approach
which uses 3D simulations to train a 7-DOF robotic arm in a control task
without any prior knowledge. The controller accepts images of the environment
as its only input, and outputs motor actions for the task of locating and
grasping a cube, over a range of initial configurations. To encourage efficient
learning, a structured reward function is designed with intermediate rewards.
We also present preliminary results in direct transfer of policies over to a
real robot, without any further training.


title:
The anisotropic Harper-Hofstadter-Mott model: competition between
  condensation and magnetic fields

abstract:
  We derive the reciprocal cluster mean-field method to study the
strongly-interacting bosonic Harper-Hofstadter-Mott model. The system exhibits
a rich phase diagram featuring band insulating, striped superfluid, and
supersolid phases. Furthermore, for finite hopping anisotropy we observe
gapless uncondensed liquid phases at integer fillings, which are analyzed by
exact diagonalization. The liquid phases at fillings 1 and 3 exhibit the same
band fillings as the fermionic integer quantum Hall effect, while the phase at
filling 2 is CT-symmetric with zero charge response. We discuss how these
phases become gapped on a quasi-one-dimensional cylinder, leading to a
quantized Hall response, which we characterize by introducing a suitable
measure for non-trivial many-body topological properties. Incompressible
metastable states at fractional filling are also observed, indicating competing
fractional quantum Hall phases. The combination of reciprocal cluster
mean-field and exact diagonalization yields a promising method to analyze the
properties of bosonic lattice systems with non-trivial unit cells in the
thermodynamic limit.


title:
Phonon-particle coupling effects in single-particle energies of
  semi-magic nuclei

abstract:
  A method is presented to evaluate the particle-phonon coupling (PC)
corrections to the single-particle energies (SPEs) in semi-magic nuclei. In
such nuclei always there is a collective low-lying $2^+$ phonon, and a strong
mixture of single-particle and particle-phonon states often occurs. As in magic
nuclei, the so-called $g^2_L$ approximation, where $g_L$ is the vertex of the
$L$-phonon creation, can be used for finding the PC correction $\delta
\Sigma^{\rm PC}(\varepsilon)$ to the initial mass operator $\Sigma_0$. In
addition to the usual pole diagram, the phonon "tadpole" diagram is also taken
into account. In semi-magic nuclei, the perturbation theory in $\delta
\Sigma^{\rm PC}(\varepsilon)$ with respect to $\Sigma_0$ is often invalid for
finding the PC corrected SPEs. Instead, the Dyson equation with the mass
operator $\Sigma(\varepsilon){=}\Sigma_0{+}\delta \Sigma^{\rm PC}(\varepsilon)$
is solved directly, without any use of the perturbation theory. Results for a
chain of semi-magic Pb isotopes are presented.


title:
Estimating the Distance Between Macro Base Station and Users in
  Heterogeneous Networks

abstract:
  In underlay heterogeneous networks (HetNets), the distance between a macro
base station (MBS) and a macro user (MU) is crucial for a small-cell based
station (SBS) to control the interference to the MU and achieve the
coexistence. To obtain the distance between the MBS and the MU, the SBS needs a
backhaul link from the macro system, such that the macro system is able to
transmit the information of the distance to the SBS through the backhaul link.
However, there may not exist any backhaul link from the macro system to the SBS
in practical situations. Thus, it is challenging for the SBS to obtain the
distance. To deal with this issue, we propose a median based (MB) estimator for
the SBS to obtain the distance between the MBS and the MU without any backhaul
link. Numerical results show that the estimation error of the MB estimator can
be as small as $4\%$.


title:
Pointwise estimates for bipolar compressible Navier-Stokes-Poisson
  system in dimension three

abstract:
  The Cauchy problem of the bipolar Navier-Stokes-Poisson system (1.1) in
dimension three is considered. We obtain the pointwise estimates of the
time-asymptotic shape of the solution, which exhibit generalized Huygens'
principle as the Navier-Stokes system. This phenomenon is the the most
important difference from the unipolar Navier-Stokes-Poisson system. Due to
non-conservative structure of the system (1.1) and interplay of two carriers
which counteracts the influence of electric field (a nonlocal term), some new
observations are essential for the proof. We make full use of the conservative
structure of the system for the total density and total momentum, and the
mechanism of the linearized unipolar Navier-Stokes-Poisson system together with
the special form of the nonlinear terms in the system for the difference of
densities and the difference of momentums. Lastly, as a byproduct, we extend
the usual $L^2(\mathbb{R}^3)$-decay rate to $L^p(\mathbb{R}^3)$-decay rate with
$p>1$ and also improve former decay rates in part.


title: Intertwinings for general $\beta$-Laguerre and $\beta$-Jacobi processes

abstract:
  We show that for $\beta \ge 1$ the semigroups of $\beta$-Laguerre and
$\beta$-Jacobi processes of different dimensions are intertwined in analogy to
a similar result for $\beta$-Dyson Brownian motion recently obtained by Ramanan
and Shkolnikov. These intertwining relations generalize to arbitrary $\beta \ge
1$ the ones obtained for $\beta=2$ by the author, O'Connell and Warren between
$h$-transformed Karlin-McGregor semigroups. Moreover they form the key step
towards constructing a multilevel process in a Gelfand-Tsetlin pattern leaving
certain Gibbs measures invariant. Finally as a by product we obtain a relation
between general $\beta$-Jacobi ensembles of different dimensions.


title: Graph Aggregation

abstract:
  Graph aggregation is the process of computing a single output graph that
constitutes a good compromise between several input graphs, each provided by a
different source. One needs to perform graph aggregation in a wide variety of
situations, e.g., when applying a voting rule (graphs as preference orders),
when consolidating conflicting views regarding the relationships between
arguments in a debate (graphs as abstract argumentation frameworks), or when
computing a consensus between several alternative clusterings of a given
dataset (graphs as equivalence relations). In this paper, we introduce a formal
framework for graph aggregation grounded in social choice theory. Our focus is
on understanding which properties shared by the individual input graphs will
transfer to the output graph returned by a given aggregation rule. We consider
both common properties of graphs, such as transitivity and reflexivity, and
arbitrary properties expressible in certain fragments of modal logic. Our
results establish several connections between the types of properties preserved
under aggregation and the choice-theoretic axioms satisfied by the rules used.
The most important of these results is a powerful impossibility theorem that
generalises Arrow's seminal result for the aggregation of preference orders to
a large collection of different types of graphs.


title: Dirac physical measures for generic diffeomorphisms

abstract:
  We prove that, for a $C^1$ generic diffeomorphism, the only Dirac physical
measures with dense statistical basin are those supported on sinks.


title: From simple-minded collections to silting objects via Koszul duality

abstract:
  Given an elementary simple-minded collection in the derived category of a
non-positive dg algebra with finite-dimensional total cohomology, we construct
a silting object via Koszul duality.


title: Some Open Problems related to Creative Telescoping

abstract:
  Creative telescoping is the method of choice for obtaining information about
definite sums or integrals. It has been intensively studied since the early
1990s, and can now be considered as a classical technique in computer algebra.
At the same time, it is still subject of ongoing research. In this paper, we
present a selection of open problems in this context. We would be curious to
hear about any substantial progress on any of these problems.


title:
Analysis of Kelner and Levin graph sparsification algorithm for a
  streaming setting

abstract:
  We derive a new proof to show that the incremental resparsification algorithm
proposed by Kelner and Levin (2013) produces a spectral sparsifier in high
probability. We rigorously take into account the dependencies across subsequent
resparsifications using martingale inequalities, fixing a flaw in the original
analysis.


title:
NMR shieldings from density functional perturbation theory: GIPAW versus
  all-electron calculations

abstract:
  We present a benchmark of the density functional linear response calculation
of NMR shieldings within the Gauge-Including Projector-Augmented-Wave method
against all-electron Augmented-Plane-Wave$+$local-orbital and uncontracted
Gaussian basis set results for NMR shieldings in molecular and solid state
systems. In general, excellent agreement between the aforementioned methods is
obtained. Scalar relativistic effects are shown to be quite large for nuclei in
molecules in the deshielded limit. The small component makes up a substantial
part of the relativistic corrections.


title:
LIC and LID considerations in the design and implementation of the MEMS
  laser pointing mechanism for the EUSO UV laser altimeter

abstract:
  The EUSO (Extreme Universe Space Observatory) project is developing a new
mission concept for the scientific research of Ultra High Energy Cosmic Rays
(UHECRs) from space. The EUSO wide-field telescope will look down from space
onto the Earth night sky to detect UV photons emitted from air showers
generated by UHECRs in our atmosphere. In this article we concentrate on the
mitigation strategies agreed so far, and in particular on the implementation of
a careful early selection and testing of subsystem materials (including
optics), design and interfaces of the subsystem and an optimization of the
instrument operational concept.


title:
Learning conditional independence structure for high-dimensional
  uncorrelated vector processes

abstract:
  We formulate and analyze a graphical model selection method for inferring the
conditional independence graph of a high-dimensional nonstationary Gaussian
random process (time series) from a finite-length observation. The observed
process samples are assumed uncorrelated over time and having a time-varying
marginal distribution. The selection method is based on testing conditional
variances obtained for small subsets of process components. This allows to cope
with the high-dimensional regime, where the sample size can be (drastically)
smaller than the process dimension. We characterize the required sample size
such that the proposed selection method is successful with high probability.


title:
Lie-X: Depth Image Based Articulated Object Pose Estimation, Tracking,
  and Action Recognition on Lie Groups

abstract:
  Pose estimation, tracking, and action recognition of articulated objects from
depth images are important and challenging problems, which are normally
considered separately. In this paper, a unified paradigm based on Lie group
theory is proposed, which enables us to collectively address these related
problems. Our approach is also applicable to a wide range of articulated
objects. Empirically it is evaluated on lab animals including mouse and fish,
as well as on human hand. On these applications, it is shown to deliver
competitive results compared to the state-of-the-arts, and non-trivial
baselines including convolutional neural networks and regression forest
methods.


title: Derivation of Cameron-Liebler line classes

abstract:
  We construct a new infinite family of Cameron-Liebler line classes in
$PG(3,q)$ with parameter $x=\frac{q^2+1}{2}$ for all odd $q$.


title: HI in Group Interactions: HCG 44

abstract:
  Extending deep observations of the neutral atomic hydrogen (HI) to the
environment around galaxy groups can reveal a complex history of group
interactions which is invisible to studies that focus on the stellar component.
Hickson Compact Group 44 (HCG 44) is a nearby example and we have combined HI
data from the Karoo Array Telescope, Westerbork Synthesis Radio Telescope, and
Arecibo Legacy Fast ALFA survey, in order to achieve high column density
sensitivity (N_HI < 2x10^18 cm^-2) to the neutral gas over a large
field-of-view beyond the compact group itself. We find the giant HI tail north
of HCG 44 contains 1.1x10^9 M_Sun of gas and extends 450 kpc from the compact
group: twice as much mass and 33% further than previously detected. However,
the additional gas is still unable to account for the known HI deficiency of
HCG 44. The tail likely formed through a strong tidal interaction and HI clouds
in the tail have survived for 1 Gyr or more after being stripped. This has
important implications for understanding the survival of neutral clouds in the
intragroup and circumgroup medium, and we discuss their survival in the context
of simulations of cold gas in hot halos. HCG 44 is one of a growing number of
galaxy groups found to have more extended HI in the intragroup and circumgroup
medium than previously measured. Our results provide constraints for
simulations on the properties of galaxy group halos, and reveal a glimpse of
what will be seen by future powerful HI telescopes and surveys.


title:
The Filter Wheel and Filters development for the X-IFU instrument
  on-board Athena

abstract:
  Athena is the large mission selected by ESA in 2013 to investigate the
science theme "Hot and Energetic Universe" and presently scheduled for launch
in 2028. One of the two instruments located at the focus of the 12 m-long
Athena telescope is the X-ray Integral Field Unit (X-IFU). This is an array of
TES micro-calorimeters that will be operated at temperatures of 50 mK in order
to perform high resolution spectroscopy with an energy resolution down to 2.5
eV at energies < 7 keV. In order to cope with the large dynamical range of
X-ray fluxes spanned by the celestial objects Athena will be observing, the
X-IFU will be equipped with a filter wheel. This will allow the user to fine
tune the instrument set-up based on the nature of the target, thus optimizing
the scientific outcomes of the observation. A few positions of the filter wheel
will also be used to host a calibration source and to allow the measurement of
the instrument intrinsic background.


title:
Character-Level Language Modeling with Hierarchical Recurrent Neural
  Networks

abstract:
  Recurrent neural network (RNN) based character-level language models (CLMs)
are extremely useful for modeling out-of-vocabulary words by nature. However,
their performance is generally much worse than the word-level language models
(WLMs), since CLMs need to consider longer history of tokens to properly
predict the next one. We address this problem by proposing hierarchical RNN
architectures, which consist of multiple modules with different timescales.
Despite the multi-timescale structures, the input and output layers operate
with the character-level clock, which allows the existing RNN CLM training
approaches to be directly applicable without any modifications. Our CLM models
show better perplexity than Kneser-Ney (KN) 5-gram WLMs on the One Billion Word
Benchmark with only 2% of parameters. Also, we present real-time
character-level end-to-end speech recognition examples on the Wall Street
Journal (WSJ) corpus, where replacing traditional mono-clock RNN CLMs with the
proposed models results in better recognition accuracies even though the number
of parameters are reduced to 30%.


title:
On the zero-viscosity limit of the Navier-Stokes equations in the
  half-space

abstract:
  We consider the zero viscosity limit of the incompressible Navier-Stokes
equations with non-slip boundary condition in the half-space for the initial
vorticity located away from the boundary. By using the vorticity formulation
and Cauchy-Kowaleskaya theorem, Maekawa proved the local in time convergence of
the Navier-Stokes equations in the half- plane to the Euler equations outside a
boundary layer and to the Prandtl equations in the boundary layer. In this
paper, we develop the direct energy method to generalize Maekawa's result to
the half-space.


title: Non-asymptotic upper bounds for the reconstruction error of PCA

abstract:
  We analyse the reconstruction error of principal component analysis (PCA) and
prove non-asymptotic upper bounds for the corresponding excess risk. These
bounds unify and improve existing upper bounds from the literature. In
particular, they give oracle inequalities under mild eigenvalue conditions. The
bounds reveal that the excess risk differs significantly from usually
considered subspace distances based on canonical angles. Our approach relies on
the analysis of empirical spectral projectors combined with concentration
inequalities for weighted empirical covariance operators and empirical
eigenvalues.


title:
Concrete Security Against Adversaries with Quantum Superposition Access
  to Encryption and Decryption Oracles

abstract:
  In 2013, Boneh and Zhandry introduced the notion of indistinguishability
(IND) in chosen plaintext (CPA) and chosen ciphertext (CCA) attacks by a
quantum adversary which is given superposition access to an oracle for
encryption and decryption queries but is restricted to classical queries in the
challenge phase. In this paper we define IND-CPA and IND-CCA notions for
symmetric encryption schemes where the adversary has full quantum superposition
access to the oracle, and give constructions that achieve these security
notions. Our results are formulated in the concrete security framework.


title: A prime geodesic theorem for higher rank buildings

abstract:
  We prove a prime geodesic theorem for compact quotients of affine buildings
and apply it to get class number asymptotics for global fields of positive
characteristic.


title: Finding faint HI structure in and around galaxies: scraping the barrel

abstract:
  Soon to be operational HI survey instruments such as APERTIF and ASKAP will
produce large datasets. These surveys will provide information about the HI in
and around hundreds of galaxies with a typical signal-to-noise ratio of $\sim$
10 in the inner regions and $\sim$ 1 in the outer regions. In addition, such
surveys will make it possible to probe faint HI structures, typically located
in the vicinity of galaxies, such as extra-planar-gas, tails and filaments.
These structures are crucial for understanding galaxy evolution, particularly
when they are studied in relation to the local environment. Our aim is to find
optimized kernels for the discovery of faint and morphologically complex HI
structures. Therefore, using HI data from a variety of galaxies, we explore
state-of-the-art filtering algorithms. We show that the intensity-driven
gradient filter, due to its adaptive characteristics, is the optimal choice. In
fact, this filter requires only minimal tuning of the input parameters to
enhance the signal-to-noise ratio of faint components. In addition, it does not
degrade the resolution of the high signal-to-noise component of a source. The
filtering process must be fast and be embedded in an interactive visualization
tool in order to support fast inspection of a large number of sources. To
achieve such interactive exploration, we implemented a multi-core CPU (OpenMP)
and a GPU (OpenGL) version of this filter in a 3D visualization environment
($\tt{SlicerAstro}$).


title:
Commissioning of the COBRA demonstrator and investigation of surface
  events as its main background

abstract:
  The COBRA collaboration investigates 0{\nu}\beta\beta-decays (neutrinoless
double beta-decays). Therefore, a demonstrator setup using coplanar-grid CdZnTe
detectors is operated at the LNGS underground laboratory. In this work, the
demonstrator was commissioned and completed, which is discussed extensively.
The demonstrator works reliably and collects low-background physics data. One
result of the analysis of the data is that surface events are the dominating
background component. To better understand and possibly discriminate this
background, surface events were studied in detail. This was done mainly using
laboratory measurements. For a better interpretation of these measurements,
simulations of particle trajectories and ranges were done. The surface
sensitivity tests showed large differences between the individual detectors.
Often, a dead-layer was determined, especially at the surfaces where the
non-collecting anode (NCA) is the outermost anode rail. Due to this, the
sensitivity of the surfaces where the collecting anode (CA) is adjacent was
typically about a factor of three larger than the NCA sensitivity. A comparison
of the pulse shape analysis methods LSE and A/E was done. Laboratory
measurements indicate, that the latter performs better. Alpha scanning
measurements were done to spatially investigate the surface sensitivity.
Plausible variations were measured. However, no hints were found how to improve
the surface event recognition. The instrumentation of the guard ring, which
surrounds the anode structure, was tested and improved the surface event
discrimination significantly. The fraction of surviving alpha events was at a
per-mill level. Important steps for a future large-scale COBRA experiment are
discussed briefly, mainly the use of an integrated read-out system. Overall,
the results indicate a large potential in background reduction for the COBRA
experiment.


title:
A Fast Proximal Gradient Algorithm for Decentralized Composite
  Optimization over Directed Networks

abstract:
  This paper proposes a fast decentralized algorithm for solving a consensus
optimization problem defined in a directed networked multi-agent system, where
the local objective functions have the smooth+nonsmooth composite form, and are
possibly nonconvex. Examples of such problems include decentralized compressed
sensing and constrained quadratic programming problems, as well as many
decentralized regularization problems. We extend the existing algorithms
PG-EXTRA and ExtraPush to a new algorithm PG-ExtraPush for composite consensus
optimization over a directed network. This algorithm takes advantage of the
proximity operator like in PG-EXTRA to deal with the nonsmooth term, and
employs the push-sum protocol like in ExtraPush to tackle the bias introduced
by the directed network. With a proper step size, we show that PG-ExtraPush
converges to an optimal solution at a linear rate under some regular
assumptions. We conduct a series of numerical experiments to show the
effectiveness of the proposed algorithm. Specifically, with a proper step size,
PG-ExtraPush performs linear rates in most of cases, even in some nonconvex
cases, and is significantly faster than Subgradient-Push, even if the latter
uses a hand-optimized step size. The established theoretical results are also
verified by the numerical results.


title:
Exponential Enhancement of the Efficiency of Quantum Annealing by
  Non-Stochastic Hamiltonians

abstract:
  Non-stoquastic Hamiltonians have both positive and negative signs in
off-diagonal elements in their matrix representation in the standard
computational basis and thus cannot be simulated efficiently by the standard
quantum Monte Carlo method due to the sign problem. We describe our analytical
studies of this type of Hamiltonians with infinite-range non-random as well as
random interactions from the perspective of possible enhancement of the
efficiency of quantum annealing or adiabatic quantum computing. It is shown
that multi-body transverse interactions like $XX$ and $XXXXX$ with positive
coefficients appended to a stoquastic transverse-field Ising model render the
Hamiltonian non-stoquastic and reduce a first-order quantum phase transition in
the simple transverse-field case to a second-order transition. This implies
that the efficiency of quantum annealing is exponentially enhanced, because a
first-order transition has an exponentially small energy gap (and therefore
exponentially long computation time) whereas a second-order transition has a
polynomially decaying gap (polynomial computation time). The examples presented
here represent rare instances where strong quantum effects, in the sense that
they cannot be efficiently simulated in the standard quantum Monte Carlo, have
analytically been shown to exponentially enhance the efficiency of quantum
annealing for combinatorial optimization problems.


title: Biasing the ferronematic - a new way to detect weak magnetic field

abstract:
  Magnetic properties of a ferronematic, i.e., nematic liquid crystal doped
with magnetic nanoparticles in low volume concentration are studied, with the
focus on the ac magnetic susceptibility. A weak dc bias magnetic field (units
of Oe) applied to the ferronematic in its isotropic phase increases the ac
magnetic susceptibility considerably. Passage of the isotropic-to-nematic phase
transition resets this enhancement irreversibly (unless the dc bias field is
applied again in the isotropic phase). These experimental findings pave a way
to application possibilities, such as low magnetic field sensors, or basic
logical elements for information storage.


title:
Bayesian electron density inference from JET lithium beam emission
  spectra using Gaussian processes

abstract:
  A Bayesian model to infer edge electron density profiles is developed for the
JET lithium beam emission spectroscopy system, measuring Li I line radiation
using 26 channels with ~1 cm spatial resolution and 10~20 ms temporal
resolution. The density profile is modelled using a Gaussian process prior, and
the uncertainty of the density profile is calculated by a Markov Chain Monte
Carlo (MCMC) scheme. From the spectra measured by the transmission grating
spectrometer, the Li line intensities are extracted, and modelled as a function
of the plasma density by a multi-state model which describes the relevant
processes between neutral lithium beam atoms and plasma particles. The spectral
model fully takes into account interference filter and instrument effects, that
are separately estimated, again using Gaussian processes. The line intensities
are inferred based on a spectral model consistent with the measured spectra
within their uncertainties, which includes photon statistics and electronic
noise. Our newly developed method to infer JET edge electron density profiles
has the following advantages in comparison to the conventional method: i)
providing full posterior distributions of edge density profiles, including
their associated uncertainties, ii) the available radial range for density
profiles is increased to the full observation range (~26 cm), iii) an
assumption of monotonic electron density profile is not necessary, iv) the
absolute calibration factor of the diagnostic system is automatically estimated
overcoming the limitation of the conventional technique and allowing us to
infer the electron density profiles for all pulses without preprocessing the
data or an additional boundary condition, and v) since the full spectrum is
modelled, the procedure of modulating the beam to measure the background signal
is only necessary for the case of overlapping of the Li line with impurity
lines.


title:
Dynamic Stark effect, light emission, and entanglement generation in a
  laser-driven quantum optical system

abstract:
  We calculate the emission spectra, the Glauber $g^{(2)}$ function, and the
entanglement of formation for a few two-level emitters coupled to a single
cavity mode and subject to an external laser-excitation. To evaluate these
quantities we couple the system to environmental degrees of freedom which leads
to dissipative dynamics. Because of the periodic time-dependence of the system
Hamiltonian, the coefficients of the (Markovian) master equation are constant
if Floquet states are used as the computational basis. Studying the emission
spectra we show that the dynamic Stark effect, i.e., the shift of spectral
lines, first appears in the second order of the laser intensity. For the
Glauber function, we find clearly distinguished parameter regimes of super- and
sub-Poissonian light emission and explain the additional features appearing for
finite laser intensity in terms of the quasienergy spectrum of the driven
emitter-cavity system. Finally, we analyze the temperature and emitter-cavity
coupling regimes where entanglement among the emitters is generated, and show
that the laser-excitation leads to a decrease of entanglement.


title:
Characterizations of core and dual core inverses in rings with
  involution

abstract:
  Let R be a unital ring with involution, we give the characterizations and
representations of the core and dual core inverses of an element in R by
Hermitian elements (or projections) and units. For example, let a in R and n is
an integer greater than or equal to 1, then a is core invertible if and only if
there exists a Hermitian element (or a projection) p such that pa=0, a^n+p is
invertible. As a consequence, a is an EP element if and only if there exists a
Hermitian element (or a projection) p such that pa=ap=0, a^n+p is invertible.
We also get a new characterization for both core invertible and dual core
invertible of a regular element by units, and their expressions are shown. In
particular, we prove that for n is an integer greater than or equal to 2, a is
both Moore-Penrose invertible and group invertible if and only if (a*)^n is
invertible along a.


title: A Tannakian approach to dimensional reduction of principal bundles

abstract:
  Let $P$ be a parabolic subgroup of a connected simply connected complex
semisimple Lie group $G$. Given a compact K\"ahler manifold $X$, the
dimensional reduction of $G$-equivariant holomorphic vector bundles over
$X\times G/P$ was carried out by the first and third authors. This raises the
question of dimensional reduction of holomorphic principal bundles over
$X\times G/P$. The method used for equivariant vector bundles does not
generalize to principal bundles. In this paper, we adapt to equivariant
principal bundles the Tannakian approach of Nori, to describe the dimensional
reduction of $G$-equivariant principal bundles over $X\times G/P$, and to
establish a Hitchin--Kobayashi type correspondence. In order to be able to
apply the Tannakian theory, we need to assume that $X$ is a complex projective
manifold.


title: The molecular gas mass of M33

abstract:
  [Abridged] Do some environments favor efficient conversion of molecular gas
into stars? To answer this, we need to be able to estimate the H2 mass.
Traditionally, this is done using CO and a few assumptions but the Herschel
observations in the FIR make it possible to estimate the molecular gas mass
independently of CO. Previous attempts to derive gas masses from dust emission
suffered from biases. Generally, dust surface densities, HI column densities,
and CO intensities are used to derive a gas-to-dust ratio (GDR) and the local
CO intensity to H2 column density ratio (XCO), sometimes allowing for an
additional CO-dark gas component (Kdark). We tested earlier methods, revealing
degeneracies among the parameters, and then used a Bayesian formalism to derive
the most likely values for each of the parameters mentioned above as a function
of position in the nearby low metallicity spiral galaxy M33. The data are from
the IRAM 30m CO(2-1) line, high-resolution HI and Herschel dust continuum
observations. Solving for GDR, XCO, and Kdark in macro pixels 500 pc in size,
we find that (i) allowing for CO-dark gas significantly improves fits; (ii)
Kdark decreases with galactocentric distance; (iii) GDR is slightly higher than
initially expected and increases with galactocentric distance; (iv) the total
amount of dark gas closely follows the radially decreasing CO emission, as
might be expected if the dark gas is H2 where CO is photodissociated. The total
amount of H2, including dark gas, yields an average XCO of twice the galactic
value of 2e20 cm^-2/(K km/s), 55% of this traced directly through CO. The
rather constant fraction of dark gas suggests that there is no large population
of diffuse H2 clouds (unrelated to GMCs) without CO emission. Unlike in large
spirals, we detect no systematic radial trend in XCO, possibly linked to the
absence of a radial decrease in CO line ratios.


title: Searching for the Time Variation in Supernova Remnant RX J1713.7-3946

abstract:
  Supernova Remnant RX J1713.7-3946 emits synchrotron X-rays and very high
energy $\gamma$-rays. Recently, thermal X-ray line emission is detected from
ejecta plasma. CO and HI observations indicate that a highly inhomogeneous
medium surrounding the SNR. It is interacting with dense molecular clouds in
the northwest and the southwest of the remnant. The origin of the $\gamma$-ray
emission from RX J1713.7-3946 is still uncertain. Detection of rapid
variability in X-ray emission from RX J1713.7-3946 indicates the magnetic field
$B$ $\sim$ mG. In this work, we investigate the time variation in X-ray flux,
luminosity and photon index of RX J1713.7-3946. For this investigation, we
study the northwest part of the remnant using Suzaku data in 2006 and 2010. We
present preliminary results based on our analysis and interpretations about
these X-ray time variability.


title: On a class of mixed Choquard-Schr\"odinger-Poisson system

abstract:
  We study the system $$ \left\{ -\Delta u+u+K(x) \phi
|u|^{q-2}u&=(I_\alpha*|u|^p)|u|^{p-2}u &&\mbox{ in }{\mathbb R}^N, -\Delta
\phi&=K(x)|u|^q&&\mbox{ in }{\mathbb R}^N, \right. $$ where $N\geq 3$,
$\alpha\in (0,N)$, $p,q>1$ and $K\geq 0$. Using a Pohozaev type identity we
first derive conditions in terms of $p,q,N,\alpha$ and $K$ for which no
solutions exist. Next, we discuss the existence of a ground state solution by
using a variational approach.


title: Quantization of compact Riemannian symmetric spaces

abstract:
  The phase space of a compact, irreducible, simply connected, Riemannian
symmetric space admits a natural family of K\"ahler polarizations parametrized
by the upper half plane $S$. Using this family, geometric quantization,
including the half-form correction, produces the field $H^{corr}\rightarrow S$
of quantum Hilbert spaces. We show that projective flatness of $H^{corr}$
implies, that the symmetric space must be isometric to a compact Lie group
equipped with a biinvariant metric. In the latter case the flatness of
$H^{corr}$ was previously established.


title: Towards Deep Compositional Networks

abstract:
  Hierarchical feature learning based on convolutional neural networks (CNN)
has recently shown significant potential in various computer vision tasks.
While allowing high-quality discriminative feature learning, the downside of
CNNs is the lack of explicit structure in features, which often leads to
overfitting, absence of reconstruction from partial observations and limited
generative abilities. Explicit structure is inherent in hierarchical
compositional models, however, these lack the ability to optimize a
well-defined cost function. We propose a novel analytic model of a basic unit
in a layered hierarchical model with both explicit compositional structure and
a well-defined discriminative cost function. Our experiments on two datasets
show that the proposed compositional model performs on a par with standard CNNs
on discriminative tasks, while, due to explicit modeling of the structure in
the feature units, affording a straight-forward visualization of parts and
faster inference due to separability of the units. Actions


title: Thermal solitons as revealed by static structure factor

abstract:
  We study, within a framework of the classical fields approximation, the
static structure factor of a weakly interacting Bose gas at thermal
equilibrium. As in a recent experiment (R. Schley et al., Phys. Rev. Lett. 111,
055301 (2013)), we find that the thermal distribution of phonons in a
three-dimensional Bose gas follows the Planck distribution. On the other hand
we find a disagreement between the Planck and phonon (calculated just like for
the bulk gas) distributions in the case of elongated quasi-one-dimensional
systems. We attribute this discrepancy to the existence of spontaneous dark
solitons (i.e., thermal solitons as reported in T. Karpiuk et al., Phys. Rev.
Lett. 109, 205302 (2012)) in an elongated Bose gas at thermal equilibrium.


title:
Total energy and potential enstrophy conserving schemes for the shallow
  water equations using Hamiltonian methods: Derivation and Properties (Part 1)

abstract:
  The shallow water equations provide a useful analogue of the fully
compressible Euler equations since they have similar characteristics:
conservation laws, inertia-gravity and Rossby waves and a (quasi-) balanced
state. In order to obtain realistic simulation results, it is desirable that
numerical models have discrete analogues of these properties. Two prototypical
examples of such schemes are the 1981 Arakawa and Lamb (AL81) C-grid total
energy and potential enstrophy conserving scheme, and the 2007 Salmon (S07)
Z-grid total energy and potential enstrophy conserving scheme. Unfortunately,
the AL81 scheme is restricted to logically square, orthogonal grids; and the
S07 scheme is restricted to uniform square grids. The current work extends the
AL81 scheme to arbitrary non-orthogonal polygonal grids and the S07 scheme to
arbitrary orthogonal spherical polygonal grids in a manner that allows both
total energy and potential enstrophy conservation, by combining Hamiltonian
methods (work done by Salmon, Gassmann, Dubos and others) and Discrete Exterior
Calculus (Thuburn, Cotter, Dubos, Ringler, Skamarock, Klemp and others).
Detailed results of the schemes applied to standard test cases are deferred to
Part 2 of this series of papers.


title:
Mode and Edgeworth expansion for the Ewens distribution and the Stirling
  numbers

abstract:
  We provide asymptotic expansions for the Stirling numbers of the first kind
and, more generally, the Ewens (or Karamata-Stirling) distribution. Based on
these expansions, we obtain some new results on the asymptotic properties of
the mode and the maximum of the Stirling numbers and the Ewens distribution.
For arbitrary $\theta>0$ and for all sufficiently large $n\in\mathbb N$, the
unique maximum of the Ewens probability mass function $$ \mathbb L_n(k) =
\frac{\theta^k}{\theta(\theta+1)\ldots(\theta+n-1)}
\genfrac{[}{]}{0pt}{}{n}{k}, \quad k=1,\ldots,n, $$ is attained at $k=
\left\lfloor \theta \log n + \frac{\theta \Gamma'(\theta)}{\Gamma(\theta)} -
\frac 12\right\rfloor$ or $k=\left\lceil \theta \log n + \frac{\theta
\Gamma'(\theta)}{\Gamma(\theta)} + \frac 12\right\rceil$. We prove that the
mode is $$ k=\left\lfloor \theta\log n - \frac{\theta
\Gamma'(\theta)}{\Gamma(\theta)}\right\rfloor $$ for a set of $n$'s of
asymptotic density $1$, yet this formula is not true for infinitely many $n$'s.


title:
Convection in axially symmetric accretion discs with microscopic
  transport coefficients

abstract:
  The vertical structure of stationary thin accretion discs is calculated from
the energy balance equation with heat generation due to microscopic ion
viscosity {\eta} and electron heat conductivity {\kappa}, both depending on
temperature. In the optically thin discs it is found that for the heat
conductivity increasing with temperature, the vertical temperature gradient
exceeds the adiabatic value at some height, suggesting convective instability
in the upper disc layer. There is a critical Prandtl number, Pr = 4/9, above
which a Keplerian disc become fully convective. The vertical density
distribution of optically thin laminar accretion discs as found from the
hydrostatic equilibrium equation cannot be generally described by a polytrope
but in the case of constant viscosity and heat conductivity. In the optically
thick discs with radiation heat transfer, the vertical disc structure is found
to be convectively stable for both absorption dominated and scattering
dominated opacities, unless a very steep dependence of the viscosity
coefficient on temperature is assumed. A polytropic-like structure in this case
is found for Thomson scattering dominated opacity.


title: Long time behavior for a nonlocal convection diffusion equation

abstract:
  In this paper we consider a nonlocal viscous Burgers equation and study the
well-posedness and asymptotic behaviour of its solutions. We prove that under
the smallness assumption on the initial data the solutions behave as the self
similar profiles of the Burgers equation with Dirac mass as the initial datum.
The first term in the asymptotic expansion of the solutions is obtained by
rescaling the solutions and proving the compactness of their trajectories.


title: One-Dimensional Super Calabi-Yau Manifolds and their Mirrors

abstract:
  We apply a definition of generalised super Calabi-Yau variety (SCY) to
supermanifolds of complex dimension one. One of our results is that there are
two SCY's having reduced manifold equal to $\mathbb{P}^1$, namely the
projective super space $\mathbb{P}^{1|2} $ and the weighted projective super
space $\mathbb{WP}^{1|1}_{(2)}$. Then we compute the corresponding sheaf
cohomology of superforms, showing that the cohomology with picture number one
is infinite dimensional, while the de Rham cohomology, which is what matters
from a physical point of view, remains finite dimensional. Moreover, we provide
the complete real and holomorphic de Rham cohomology for generic projective
super spaces $\mathbb P^{n|m}$. We also determine the automorphism groups:
these always match the dimension of the projective super group with the only
exception of $\mathbb{P}^{1|2} $, whose automorphism group turns out to be
larger than the projective general linear supergroup. By considering the
cohomology of the super tangent sheaf, we compute the deformations of
$\mathbb{P}^{1|m}$, discovering that the presence of a fermionic structure
allows for deformations even if the reduced manifold is rigid. Finally, we show
that $\mathbb{P}^{1|2} $ is self-mirror, whereas $\mathbb{WP} ^{1|1}_{(2)}$ has
a zero dimensional mirror. Also, the mirror map for $\mathbb{P}^{1|2}$
naturally endows it with a structure of $N=2$ super Riemann surface.


title:
Transient superconductivity from electronic squeezing of optically
  pumped phonons

abstract:
  Advances in light sources and time resolved spectroscopy have made it
possible to excite specific atomic vibrations in solids and to observe the
resulting changes in electronic properties but the mechanism by which phonon
excitation causes qualitative changes in electronic properties, has remained
unclear. Here we show that the dominant symmetry-allowed coupling between
electron density and dipole active modes implies an electron density-dependent
squeezing of the phonon state which provides an attractive contribution to the
electron-electron interaction, independent of the sign of the bare
electron-phonon coupling and with a magnitude proportional to the degree of
laser-induced phonon excitation. Reasonable excitation amplitudes lead to
non-negligible attractive interactions that may cause significant transient
changes in electronic properties including superconductivity. The mechanism is
generically applicable to a wide range of systems, offering a promising route
to manipulating and controlling electronic phase behavior in novel materials.


title: Questioning the recent observation of quantum Hawking radiation

abstract:
  A recent article [J. Steinhauer, Nat. Phys. 12, 959 (2016)] has reported the
observation of quantum Hawking radiation and its entanglement in an analogue
black hole. This paper analyses the published evidence, its consistency with
theoretical bounds and the statistical significance of the results. The
analysis raises severe doubts on the observation of Hawking radiation.


title:
Light-Front spin-dependent Spectral Function and Nucleon Momentum
  Distributions for a Three-Body System

abstract:
  Poincare' covariant definitions for the spin-dependent spectral function and
for the momentum distributions within the light-front Hamiltonian dynamics are
proposed for a three-fermion bound system, starting from the light-front wave
function of the system. The adopted approach is based on the Bakamjian-Thomas
construction of the Poincare' generators, that allows one to easily import the
familiar and wide knowledge on the nuclear interaction into a light-front
framework. The proposed formalism can find useful applications in refined
nuclear calculations, like the ones needed for evaluating the EMC effect or the
semi-inclusive deep inelastic cross sections with polarized nuclear targets,
since remarkably the light-front unpolarized momentum distribution by
definition fulfills both normalization and momentum sum rules. It is also shown
a straightforward generalization of the definition of the light-front spectral
function to an A-nucleon system.


title: Localization of Cofibration Categories and Groupoid $C^*$-algebras

abstract:
  We prove that relative functors out of a cofibration category are essentially
the same as relative functors which are only defined on the subcategory of
cofibrations. As an application we give a new construction of the functor that
assigns to a groupoid its groupoid $C^*$-algebra and thereby its topological
$K$-theory spectrum.


title:
Quantitative identification of technological discontinuities using
  simulation modeling

abstract:
  The aim of this paper is to develop and test metrics to quantitatively
identify technological discontinuities in a knowledge network. We developed
five metrics based on innovation theories and tested the metrics by a
simulation model-based knowledge network and hypothetically designed
discontinuity. The designed discontinuity is modeled as a node which combines
two different knowledge streams and whose knowledge is dominantly persistent in
the knowledge network. The performances of the proposed metrics were evaluated
by how well the metrics can distinguish the designed discontinuity from other
nodes on the knowledge network. The simulation results show that the
persistence times # of converging main paths provides the best performance in
identifying the designed discontinuity: the designed discontinuity was
identified as one of the top 3 patents with 96~99% probability by Metric 5 and
it is, according to the size of a domain, 12~34% better than the performance of
the second best metric. Beyond the simulation analysis, we tested the metrics
using a patent set representative of the Magnetic information storage domain.
The three representative patents associated with a well-known breakthrough
technology in the domain, the giant magneto-resistance (GMR) spin valve sensor,
were selected based on the qualitative studies, and the metrics were tested by
how well the metrics identify the selected patents as top-ranked patents. The
empirical results fully support the simulation results and therefore the
persistence times # of converging main paths is recommended for identifying
technological discontinuities for any technology.


title:
Forecasting performance of CMB experiments in the presence of complex
  foreground contaminations

abstract:
  We present a new, semi-analytic framework for estimating the level of
residuals present in CMB maps derived from multi-frequency Cosmic Microwave
Background (CMB) data and forecasting their impact on cosmological parameters.
The data are assumed to contain non-negligible signals of astrophysical and/or
Galactic origin, which we clean using parametric component separation
technique. We account for discrepancies between the foreground model assumed
during the separation procedure and the true one, allowing for differences in
scaling laws and/or their spatial variations. Our estimates and their
uncertainties include both systematic and statistical effects and are averaged
over the instrumental noise and CMB signal realizations. The framework can be
further extended to account self-consistently for existing uncertainties in the
foreground models. We demonstrate and validate the framework on simple study
cases which aim at estimating the tensor-to-scalar ratio, r. The proposed
approach is computationally efficient permitting an investigation of hundreds
of set-ups and foreground models on a single CPU.


title: Chains in shard lattices and BHZ posets

abstract:
  For every finite Coxeter group W , we prove that the number of chains in the
shard intersection lattice introduced by Reading on the one hand and in the BHZ
poset introduced by Bergeron, Zabrocki and the third author on the other hand,
are the same. We also show that these two partial orders are related by an
equality between generating series for their M{\"o}bius numbers, and provide a
dimension-preserving bijection between the order complex on the BHZ poset and
the pulling triangulation of the permutahedron arising from the right weak
order, analogous to the bijection defined by Reading between the order complex
of the shard poset and the same triangulation of the permutahedron.


title: Critical slowing down in purely elastic `snap-through' instabilities

abstract:
  Many elastic structures have two possible equilibrium states: from umbrellas
that become inverted in a sudden gust of wind, to nano-electromechanical
switches, origami patterns and the hopper popper, which jumps after being
turned inside-out. These systems typically transition from one state to the
other via a rapid `snap-through'. Snap-through allows plants to gradually store
elastic energy, before releasing it suddenly to generate rapid motions, as in
the Venus flytrap. Similarly, the beak of the hummingbird snaps through to
catch insects mid-flight, while technological applications are increasingly
exploiting snap-through instabilities. In all of these scenarios, it is the
ability to repeatedly generate fast motions that gives snap-through its
utility. However, estimates of the speed of snap-through suggest that it should
occur more quickly than is usually observed. Here, we study the dynamics of
snap-through in detail, showing that, even without dissipation, the dynamics
slow down close to the snap-through transition. This is reminiscent of the
slowing down observed in critical phenomena, and provides a handheld
demonstration of such phenomena, as well as a new tool for tuning dynamic
responses in applications of elastic bistability.


title:
Moderate deviations for bipower variation of general function and
  Hayashi-Yoshida estimators

abstract:
  We consider the moderate deviations behaviors for two (co-) volatility
estima-tors: generalised bipower variation, Hayashi-Yoshida estimator. The
results are obtained by using a new result about the moderate deviations
principle for m-dependent random variables based on the Chen-Ledoux type
condition. In the last decade there has been a considerable development of the
asymptotic theory for processes observed at a high frequency. This was mainly
motivated by financial applications , where the data, such as stock prices or
currencies, are observed very frequently. As under the no-arbitrage assumptions
price processes must follow a semimartingale, there was a need for
probabilistic tools for functionals of semimartingales based on high frequency
observations. Inspired by potential applications, probabilists started to
develop limit theorems for semimartingales. Statisticians applied the
asymptotic theory to analyze the path properties of discretely observed
semimartingales: for the estimation of certain volatility functionals and
realised jumps, or for performing various test procedures. We consider X t = (X
1,t , X 2,t) t$\in$[0,T ] a 2-dimensional semimartingale, defined on the
filtred probability space ($\Omega$, F , (F t) [0,T ] , P), of the form


title: Cutting self-similar space-filling sphere packings

abstract:
  Any space-filling packing of spheres can be cut by a plane to obtain a
space-filling packing of disks. Here, we deal with space-filling packings
generated using inversive geometry leading to exactly self-similar fractal
packings. First, we prove that cutting along a random hyperplane leads in
general to a packing with a fractal dimension of the one of the uncut packing
minus one. Second, we find special cuts which can be constructed themselves by
inversive geometry. Such special cuts have specific fractal dimensions, which
we demonstrate by cutting a three- and a four-dimensional packing. The increase
in the number of found special cuts with respect to a cutoff parameter suggests
the existence of infinitely many topologies with distinct fractal dimensions.


title:
Identification of a Griffiths singularity in a geometrically frustrated
  antiferromagnet

abstract:
  We report the observation of a Griffiths Phase in the geometrically
frustrated antiferromagnet DyBaCo${_4}$O${_{7+\delta}}$. Its onset is
determined using measurements of the thermoremanent magnetization, which is
shown to be superior to conventional in-field measurement protocols for the
identification of the Griffiths Phase. Within this phase, the temporal
relaxation of magnetization exhibits a functional form which is expected for
Heisenberg systems, reflecting the nature of spin interactions in this class of
materials. Interestingly, the effective Co${^{2+}}$/Co${^{3+}}$ ratio tailored
by varying the oxygen non-stoichiometry $\delta$ is only seen to influence the
antiferromagnetic ordering temperature ($T{_N}$), leaving the Griffiths
Temperature ($T{_G}$) invariant.


title: On the distance to the North Polar Spur and the local CO-H2 factor

abstract:
  Most models identify the X-ray bright North Polar Spur (NPS) with a hot
interstellar (IS) bubble in the Sco-Cen star-forming region at $\simeq$130 pc.
An opposite view considers the NPS as a distant structure associated with
Galactic nuclear outflows. Constraints on the NPS distance can be obtained by
comparing the foreground IS gas column inferred from X-ray absorption to the
distribution of gas and dust along the line of sight. Absorbing columns towards
shadowing molecular clouds simultaneously constrain the CO-H$_{2}$ conversion
factor. We derived the columns of X-ray absorbing matter NH(abs) from spectral
fitting of dedicated XMM-Newton observations towards the NPS southern terminus
(l=29{\deg}, b=+5 to +11{\deg}). The IS matter distribution was obtained from
absorption lines in stellar spectra, 3D dust maps and emission data, including
high spatial resolution CO measurements recorded for this purpose. NH(abs)
varies from $\simeq$ 4.3 to $\simeq$ 1.3 x 10$^{21}$ cm$^{-2}$ along the 19
fields. Relationships between X-ray brightness, absorbing column and hardness
ratio demonstrate a brightness decrease with latitude governed by increasing
absorption. The comparison with absorption data, local and large-scale dust
maps rules out a NPS near side closer than 300 pc. The correlation between
NH(abs) and the reddening increases with the sightline length from 300 pc to 4
kpc and is the tightest with Planck $\tau_{353}$-based reddening, suggesting a
much larger distance. N(H)/E(B-V) $\simeq$ 4.1 x 10$^{21}$ cm$^{-2}$
mag$^{-1}$. NH(abs) absolute values are compatible with HI-CO clouds at -5
$\leq$ V(LSR) $\leq$ +25 to +45 km s$^{-1}$ and a NPS potentially far beyond
the Local Arm. A molecular cloud shadow at b=+9deg constrains X$_{CO}$ to
$\leq$ 1.0 x 10$^{20}$ cm$^{-2}$ K$^{-1}$ km$^{-1}$ s. The average X$_{CO}$ is
$\leq$ 0.75 x 10$^{20}$ cm$^{-2}$ K$^{-1}$ km$^{-1}$ s.


title:
Nonequilibrium steady states in a closed inhomogeneous asymmetric
  exclusion process with particle nonconservation

abstract:
  We study asymmetric exclusion processes (TASEP) on a nonuniform
one-dimensional ring consisting of two segments having unequal hopping rates,
or {\em defects}. We allow weak particle nonconservation via Langmuir kinetics
(LK), that are parameterised by generic unequal attachment and detachment
rates. For an extended defect, in the thermodynamic limit the system
generically displays inhomogeneous density profiles in the steady state - the
faster segment is either in a phase with spatially varying density having no
density discontinuity, or a phase with a discontinuous density changes.
Nonequilibrium phase transitions between them are controlled by the
inhomogeneity and LK. The slower segment displays only macroscopically uniform
bulk density profiles in the steady states, reminiscent of the maximal current
phase of TASEP but with a bulk density generally different from half. With a
point defect, there are low and high density spatially uniform phases as well,
in addition to the inhomogeneous density profiles observed for an extended
defect. In all the cases, it is argued that the the mean particle density in
the steady state is controlled only by the ratio of the LK attachment and
detachment rates.


title: A Unified Gender-Aware Age Estimation

abstract:
  Human age estimation has attracted increasing researches due to its wide
applicability in such as security monitoring and advertisement recommendation.
Although a variety of methods have been proposed, most of them focus only on
the age-specific facial appearance. However, biological researches have shown
that not only gender but also the aging difference between the male and the
female inevitably affect the age estimation. To our knowledge, so far there
have been two methods that have concerned the gender factor. The first is a
sequential method which first classifies the gender and then performs age
estimation respectively for classified male and female. Although it promotes
age estimation performance because of its consideration on the gender semantic
difference, an accumulation risk of estimation errors is unavoidable. To
overcome drawbacks of the sequential strategy, the second is to regress the age
appended with the gender by concatenating their labels as two dimensional
output using Partial Least Squares (PLS). Although leading to promotion of age
estimation performance, such a concatenation not only likely confuses the
semantics between the gender and age, but also ignores the aging discrepancy
between the male and the female. In order to overcome their shortcomings, in
this paper we propose a unified framework to perform gender-aware age
estimation. The proposed method considers and utilizes not only the semantic
relationship between the gender and the age, but also the aging discrepancy
between the male and the female. Finally, experimental results demonstrate not
only the superiority of our method in performance, but also its good
interpretability in revealing the aging discrepancy.


title: D-class of dark energy against $\Lambda$CDM in Brans-Dicke cosmology

abstract:
  Three general models of dynamical interacting dark energy (D-class) are
investigated in the context of Brans-Dicke cosmology. All cosmological
quantities such as equation of state parameters, deceleration parameters,
Hubble function, and the density ratio are calculated as a function of redshift
parameter. The most important part of this paper is fitting of models to the
observational data (SNIa+BAO$_A$+$Omh^{2}$). We obtain a table of best fit
value of parameters and report $\chi_{tot}^2/dof$ and Akaike Information
Criterion (AIC) for each model. By these diagnostic tools, we find that some
models have no chance against $\Lambda$CDM and some (e.g. $\mathcal{BD-D}C2$
and $\mathcal{BD-D}A^*$) render the best fit quality. Specially, the value of
AIC analysis and figures show that the interacting $\mathcal{BD-D}C2$ model fit
perfectly with overall data and reveals a strong evidence in favor of this
model, against $\Lambda$CDM.


title: Photospheric response to EB-like event

abstract:
  Ellerman Bombs are signatures of magnetic reconnection, which is an important
physical process in the solar atmosphere. How and where they occur is a subject
of debate. In this paper we analyse Sunrise/IMaX data together with 3D MHD
simulations that aim to reproduce the exact scenario proposed for the formation
of these features. Although the observed event seems to be more dynamic and
violent than the simulated one, simulations clearly confirm the basic scenario
for the production of EBs. The simulations also reveal the full complexity of
the underlying process. The simulated observations show that the Fe I 525.02 nm
line gives no information on the height where reconnection takes place. It can
only give clues about the heating in the aftermath of the reconnection. The
information on the magnetic field vector and velocity at this spatial
resolution is, however, extremely valuable because it shows what numerical
models miss and how they can be improved.


title: Rigidity of the Laughlin liquid

abstract:
  We consider general N-particle wave functions that have the form of a product
of the Laughlin state with filling factor $1/\ell$ and an analytic function of
the N variables. This is the most general form of a wave function that can
arise through a perturbation of the Laughlin state by external potentials or
impurities, while staying in the lowest Landau level and maintaining the strong
correlations of the original state. We show that the perturbation can only
shift or lower the 1-particle density but nowhere increase it above a maximum
value. Consequences of this bound for the response of the Laughlin state to
external fields are discussed.

categories: math-ph cond-mat.mes-hall cond-mat.quant-gas math.MP


title:
Stability estimates for Navier-Stokes equations and application to
  inverse problems

abstract:
  In this work, we present some new Carleman inequalities for Stokes and Oseen
equations with non-homogeneous boundary conditions. These estimates lead to log
type stability inequalities for the problem of recovering the solution of the
Stokes and Navier-Stokes equations from both boundary and distributed
observations. These inequalities fit the well-known unique continuation result
of Fabre and Lebeau [18]: the distributed observation only depends on interior
measurement of the velocity, and the boundary observation only depends on the
trace of the velocity and of the Cauchy stress tensor measurements. Finally, we
present two applications for such inequalities. First, we apply these estimates
to obtain stability inequalities for the inverse problem of recovering Navier
or Robin boundary coefficients from boundary measurements. Next, we use these
estimates to deduce the rate of convergence of two reconstruction methods of
the Stokes solution from the measurement of Cauchy data: a quasi-reversibility
method and a penalized Kohn-Vogelius method.


title:
Detecting fully irreducible automorphisms: a polynomial time algorithm.
  With an appendix by Mark C. Bell

abstract:
  In \cite{Ka14} we produced an algorithm for deciding whether or not an
element $\phi\in Out(F_N)$ is an iwip ("fully irreducible") automorphism. At
several points that algorithm was rather inefficient as it involved some
general enumeration procedures as well as running several abstract processes in
parallel. In this paper we refine the algorithm from \cite{Ka14} by eliminating
these inefficient features, and also by eliminating any use of mapping class
groups algorithms.
  Our main result is to produce, for any fixed $N\ge 3$, an algorithm which,
given a topological representative $f$ of an element $\phi$ of $Out(F_N)$,
decides in polynomial time in terms of the "size" of $f$, whether or not $\phi$
is fully irreducible.
  In addition, we provide a train track criterion of being fully irreducible
which covers all fully irreducible elements of $Out(F_N)$, including both
atoroidal and non-atoroidal ones.
  We also give an algorithm, alternative to that of Turner, for finding all the
indivisible Nielsen paths in an expanding train track map, and estimate the
complexity of this algorithm.
  An appendix by Mark Bell provides a polynomial upper bound, in terms of the
size of the topological representative, on the complexity of the
Bestvina-Handel algorithm \cite{BH92} for finding either an irreducible train
track representative or a topological reduction.


title: The conical complex Monge-Amp\`ere equations on K\"ahler manifolds

abstract:
  In this paper, by providing the uniform gradient estimates for a sequence of
the approximating equations, we prove the existence, uniqueness and regularity
of the conical parabolic complex Monge-Amp\`ere equation with weak initial
data. As an application, we prove a regularity estimates, that is, any
$L^{\infty}$-solution of the conical complex Monge-Amp\`ere equation admits the
$C^{2,\alpha,\beta}$-regularity.


title:
Search reliability and search efficiency of combined L\'evy-Brownian
  motion: long relocations mingled with thorough local exploration

abstract:
  A combined dynamics consisting of Brownian motion and L\'evy flights is
exhibited by a variety of biological systems performing search processes.
Assessing the search reliability of ever locating the target and the search
efficiency of doing so economically of such dynamics thus poses an important
problem. Here we model this dynamics by a one-dimensional fractional
Fokker-Planck equation combining unbiased Brownian motion and L\'evy flights.
By solving this equation both analytically and numerically we show that the
superposition of recurrent Brownian motion and L\'evy flights with stable
exponent $\alpha<1$, by itself implying zero probability of hitting a point on
a line, lead to transient motion with finite probability of hitting any point
on the line. We present results for the exact dependence of the values of both
the search reliability and the search efficiency on the distance between the
starting and target positions as well as the choice of the scaling exponent
$\alpha$ of the L\'evy flight component.


title: All passive photonic power divider with arbitrary split ratio

abstract:
  Integrated optical power splitter is one of the fundamental building blocks
in photonic integrated circuits (PIC). Conventional multimode interferometer
based power splitter is widely used as it has reasonable footprint and is easy
to fabricate. However, it is challenging to realize arbitrary split ratio
especially for multi-outputs. In this work, an ultra-compact power splitter
with a QR code-like nanostructure is designed by a nonlinear fast search method
(FSM). The highly functional structure is composed of a number of freely
designed square pixels with the size of 120nm x 120nm which could be either
dielectric or air. The lightwaves are scattered by a number of etched squares
with optimized locations and the scattered waves superimpose at the outputs
with the desired power ratio. We demonstrate 1x2 splitters with 1:1, 1:2, 1:3
split ratios and a 1x3 splitter with the ratio of 1:2:1. The footprint for all
the devices is only 3.6umx3.6 um. Well-controlled split ratios are measured for
all the cases. The measured transmission efficiencies of all the splitters are
close to 80% over 30 nm wavelength range.


title: Ising and Gross-Neveu model in next-to-leading order

abstract:
  We study scalar and chiral fermionic models in next-to-leading order with the
help of the functional renormalisation group. Their critical behaviour is of
special interest in condensed matter systems, in particular graphene. To derive
the beta functions, we make extensive use of computer algebra. The resulting
flow equations were solved with pseudo-spectral methods to guarantee high
accuracy. New estimates on critical quantities for both the Ising and the
Gross-Neveu model are provided. For the Ising model, the estimates agree with
earlier renormalisation group studies of the same level of approximation. By
contrast, the approximation for the Gross-Neveu model retains many more
operators than all earlier studies. For two Dirac fermions, the results agree
with both lattice and large-$N_f$ calculations, but for a single flavour,
different methods disagree quantitatively, and further studies are necessary.


title: Measurement of the photon and jet production with the ATLAS detector

abstract:
  Production of prompt isolated photons at hadron colliders provides a probe of
perturbative QCD and can be used to study the gluon density function of the
proton. The ATLAS collaboration has performed precise measurements of the
inclusive production of isolated prompt photons in 20.2 fb${}^{-1}$ of data
collected at $\sqrt{s}=8$ TeV and in 6.4 pb${}^{-1}$ of data collected at
$\sqrt{s}=13$ TeV. The measurements are compared with state-of-the-art theory
predictions at NLO in QCD and with predictions of several MC generators.
Production of inclusive jets at hadron colliders also provides a probe of
perturbative QCD. The inclusive jet production cross-section was measured in 78
pb${}^{-1}$ of data collected at $\sqrt{s}=13$ TeV. Results have been compared
with (state-of-the-art) theory predictions at NLO in QCD, interfaced with
different parton distribution functions.


title:
RAVE stars in K2 - I. Improving RAVE red giants spectroscopy using
  asteroseismology from K2 Campaign 1

abstract:
  We present a set of 87 RAVE stars with detected solar like oscillations,
observed during Campaign 1 of the K2 mission (RAVE K2-C1 sample). This dataset
provides a useful benchmark for testing the gravities provided in RAVE Data
Release 4 (DR4), and is key for the calibration of the RAVE Data Release 5
(DR5). In the present work, we use two different pipelines, GAUFRE (Valentini
et al. 2013) and Sp_Ace (Boeche & Grebel 2016), to determine atmospheric
parameters and abundances by fixing log(g) to the seismic one. Our strategy
ensures highly consistent values among all stellar parameters, leading to more
accurate chemical abundances. A comparison of the chemical abundances obtained
here with and without the use of seismic log(g) information has shown that an
underestimated (overestimated) gravity leads to an underestimated
(overestimated) elemental abundance (e.g. [Mg/H] is underestimated by ~0.25 dex
when the gravity is underestimated by 0.5 dex). We then perform a comparison
between the seismic gravities and the spectroscopic gravities presented in the
RAVE DR4 catalogue, extracting a calibration for log(g) of RAVE giants in the
colour interval 0.50<(J - Ks)<0.85. Finally, we show a comparison of the
distances, temperatures, extinctions (and ages) derived here for our RAVE K2-C1
sample with those derived in RAVE DR4 and DR5.DR5 performs better than DR4
thanks to the seismic calibration, although discrepancies can still be
important for objects for which the difference between DR4/DR5 and seismic
gravities differ by more than ~0.5 dex. The method illustrated in this work
will be used for analysing RAVE targets present in the other K2 campaigns, in
the framework of Galactic Archaeology investigations.


title:
Length dependence of the thermal conductance of alkane-based
  single-molecule junctions: An ab-initio study

abstract:
  Motivated by recent experiments, we present here a systematic ab-initio study
of the length dependence of the thermal conductance of single-molecule
junctions. We make use of a combination of density functional theory with
non-equilibrium Green's function techniques to investigate the length
dependence of the phonon transport in single alkane chains, contacted with gold
electrodes via both thiol and amine anchoring groups. Additionally, we study
the effect of the substitution of the hydrogen atoms in the alkane chains by
heavier fluorine atoms to form polytetrafluoroethylenes. Our results
demonstrate that (i) the room-temperature thermal conductance is fairly
length-independent for chains with more than 5 methylene units and (ii) the
efficiency of the thermal transport is strongly influenced by the strength of
the phononic metal-molecule coupling. Our study sheds new light onto the phonon
transport in molecular junctions, and it provides clear guidelines for the
design of molecular junctions for thermal management.


title:
Observation of enhanced chiral asymmetries in the inner-shell
  photoionization of uniaxially oriented methyloxirane enantiomers

abstract:
  Most large molecules are chiral in their structure: they exist as two
enantiomers, which are mirror images of each other. Whereas the rovibronic
sublevels of two enantiomers are almost identical, it turns out that the
photoelectric effect is sensitive to the absolute configuration of the ionized
enantiomer - an effect termed Photoelectron Circular Dichroism (PECD). Our
comprehensive study demonstrates that the origin of PECD can be found in the
molecular frame electron emission pattern connecting PECD to other fundamental
photophysical effects as the circular dichroism in angular distributions
(CDAD). Accordingly, orienting a chiral molecule in space enhances the PECD by
a factor of about 10.


title: Visualizing septins in early Drosophila embryos

abstract:
  Functional studies in Drosophila have been key for establishing a role for
the septin family of proteins in animal cell division and thus extending for
the first time observations from the budding yeast to animal cells. Visualizing
the distribution of specific septins in different Drosophila tissues and, in
particular, in the Drosophila embryo, together with biochemical and mutant
phenotype data, has contributed important advances to our understanding of
animal septin biology, suggesting roles in processes other than in cytokinesis.
Septin localization using immunofluorescence assays has been possible due to
the generation of antibodies against different Drosophila septins. The recent
availability of lines expressing fluorescent protein fusions of specific
septins further promises to facilitate studies on septin dynamics. Here, we
provide protocols for preparing early Drosophila embryos to visualize septins
using immunofluorescence assays and live fluorescence microscopy. The genetic
tractability of the Drosophila embryo together with its amenability to
high-resolution fluorescence microscopy promises to provide novel insights into
animal septin structure and function.


title:
Exclusive photoproduction of a $\gamma\,\rho$ pair with a large
  invariant mass

abstract:
  Exclusive photoproduction of a $\gamma\,\rho$ pair in the kinematics where
the pair has a large invariant mass and the final nucleon has a small
transverse momentum is described in the collinear factorization framework. The
scattering amplitude is calculated at leading order in $\alpha_s$ and the
differential cross sections for the process where the $\rho-$meson is either
longitudinally or transversely polarized are estimated in the kinematics of the
JLab 12-GeV experiments.


title:
Stable Green ring of the Drinfeld doubles of the generalised Taft
  algebras (corrections and new results)

abstract:
  We return to the fusion rules for the Drinfeld double of the duals of the
generalised Taft algebras that we studied in [9]. We first correct some proofs
and statements in [9] that were incorrect, using stable homomorphisms. We then
complete this with new results on fusion rules for the modules we had not
studied in [9] and a classification of endotrivial and algebraic modules.


title:
An efficient Cellular Potts Model algorithm that forbids cell
  fragmentation

abstract:
  The Cellular Potts Model (CPM) is a lattice based modeling technique which is
widely used for simulating cellular patterns such as foams or biological
tissues. Despite its realism and generality, the standard Monte Carlo algorithm
used in the scientific literature to evolve this model preserves connectivity
of cells on a limited range of simulation temperature only. We present a new
algorithm in which cell fragmentation is forbidden for all simulation
temperatures. This allows to significantly enhance realism of the simulated
patterns. It also increases the computational efficiency compared with the
standard CPM algorithm even at same simulation temperature, thanks to the time
spared in not doing unrealistic moves. Moreover, our algorithm restores the
detailed balance equation, ensuring that the long-term stage is independent of
the chosen acceptance rate and chosen path in the temperature space.


title:
A new galactic chemical evolution model with dust: results for dwarf
  irregular galaxies and DLA systems

abstract:
  We present a galactic chemical evolution model which adopts updated
prescriptions for all the main processes governing the dust cycle. We follow in
detail the evolution of the abundances of several chemical species (C, O, S,
Si, Fe and Zn) in the gas and dust of a typical dwarf irregular galaxy. The
dwarf irregular galaxy is assumed to evolve with a low but continuous level of
star formation and experience galactic winds triggered by supernova explosions.
We predict the evolution of the gas to dust ratio in such a galaxy and discuss
critically the main processes involving dust, such as dust production by AGB
stars and Type II SNe, destruction and accretion (gas condensation in clouds).
We then apply our model to Damped Lyman-Alpha systems which are believed to be
dwarf irregulars, as witnessed by their abundance patterns. Our main
conclusions are: i) we can reproduce the observed gas to dust ratio in dwarf
galaxies. ii) We find that the process of dust accretion plays a fundamental
role in the evolution of dust and in certain cases it becomes the dominant
process in the dust cycle. On the other hand, dust destruction seems to be a
negligible process in irregulars. iii) Concerning Damped Lyman-Alpha systems,
we show that the observed gas-phase abundances of silicon, normalized to
volatile elements (zinc and sulfur), are in agreement with our model. iv) The
abundances of iron and silicon in DLA systems suggest that the two elements
undergo a different history of dust formation and evolution. Our work casts
light on the nature of iron-rich dust: the observed depletion pattern of iron
is well reproduced only when an additional source of iron dust is considered.
Here we explore the possibility of a contribution from Type Ia SNe as well as
an efficient accretion of iron nano-particles.


title: Stochastic Analysis with Modelled Distributions

abstract:
  Using a Besov topology on spaces of modelled distributions in the framework
of Hairer's regularity structures, we prove the reconstruction theorem on these
Besov spaces with negative regularity. The Besov spaces of modelled
distributions are shown to be UMD Banach spaces and of martingale type $2$. As
a consequence, this gives access to a rich stochastic integration theory and to
existence and uniqueness results for mild solutions of semilinear stochastic
partial differential equations in these spaces of modelled distributions and
for distribution-valued SDEs. Furthermore, we provide a Fubini type theorem
allowing to interchange the order of stochastic integration and reconstruction.


title: Three-players conflicting interest games and nonlocality

abstract:
  We outline the general construction of three-players games with incomplete
information which fulfil the following conditions: (i) symmetry with respect to
the exchange of the players; (ii) the existence of the upper bound for total
payoff resulting from Bell inequalities; (iii) the existence of both fair and
unfair Nash equilibria saturating this bound. Conditions (i)$\div$(iii) imply
that we are dealing with conflicting interest games. An explicit example of
such a game is given. A quantum counterpart of this game is considered which is
obtained by keeping the same utilities but replacing classical advisor by a
quantum one. It is shown that the quantum game possesses only fair equilibria
with strictly higher payoffs than in the classical case. This implies that
quantum nonlocality can be used to resolve a conflict between players.


title:
Robust Resource Allocation for MIMO Wireless Powered Communication
  Networks Based on a Non-linear EH Model

abstract:
  In this paper, we consider a multiple-input multiple-output wireless powered
communication network (MIMO-WPCN), where multiple users harvest energy from a
dedicated power station in order to be able to transmit their information
signals to an information receiving station. Employing a practical non-linear
energy harvesting (EH) model, we propose a joint time allocation and power
control scheme, which takes into account the uncertainty regarding the channel
state information (CSI) and provides robustness against imperfect CSI
knowledge. In particular, we formulate two non-convex optimization problems for
different objectives, namely system sum throughput maximization and
maximization of the minimum individual throughput across all wireless powered
users. To overcome the non-convexity, we apply several transformations along
with a one-dimensional search to obtain an efficient resource allocation
algorithm. Numerical results reveal that a significant performance gain can be
achieved when the resource allocation is designed based on the adopted
non-linear EH model instead of the conventional linear EH model. Besides,
unlike a non-robust baseline scheme designed for perfect CSI, the proposed
resource allocation schemes are shown to be robust against imperfect CSI
knowledge.


title: Nonlinear amplitude dynamics in flagellar beating

abstract:
  The physical basis of flagellar and ciliary beating is a major problem in
biology which is still far from completely understood. The fundamental
cytoskeleton structure of cilia and flagella is the axoneme, a cylindrical
array of microtubule doublets connected by passive crosslinkers and dynein
motor proteins. The complex interplay of these elements leads to the generation
of self-organized bending waves. Although many mathematical models have been
proposed to understand this process, few attempts have been made to assess the
role of dyneins on the nonlinear nature of the axoneme. Here, we investigate
the nonlinear dynamics of flagella by considering an axonemal sliding control
mechanism for dynein activity. This approach unveils the nonlinear selection of
the oscillation amplitudes, which are typically either missed or prescribed in
mathematical models. The explicit set of nonlinear equations are derived and
solved numerically. Our analysis reveals the spatiotemporal dynamics of dynein
populations and flagellum shape for different regimes of motor activity, medium
viscosity and flagellum elasticity. Unstable modes saturate via the coupling of
dynein kinetics and flagellum shape without the need of invoking a nonlinear
axonemal response. Hence, our work reveals a novel mechanism for the saturation
of unstable modes in axonemal beating.


title: Tropical Ideals

abstract:
  We introduce and study a special class of ideals, called tropical ideals, in
the semiring of tropical polynomials, with the goal of developing a useful and
solid algebraic foundation for tropical geometry. The class of tropical ideals
strictly includes the tropicalizations of classical ideals, and allows us to
define subschemes of tropical toric varieties, generalizing
[Giansiracusa-Giansiracusa]. We investigate some of the basic structure of
tropical ideals, and show that they satisfy many desirable properties that
mimic the classical setup. In particular, every tropical ideal has an
associated variety, which we prove is always a finite polyhedral complex. In
addition we show that tropical ideals satisfy the ascending chain condition,
even though they are typically not finitely generated, and also the weak
Nullstellensatz.


title: New results related to QGP-like effects in small systems with ALICE

abstract:
  Results on the production of $\pi^{\pm}$, $\textrm{K}^{\pm}$,
$\textrm{p}(\bar{\textrm{p}})$, $\Lambda(\bar{\Lambda})$, $\Xi^{-}
\left(\bar{\Xi}^{+}\right)$ and $\Omega^{-} \left(\bar{\Omega}^{+}\right)$ at
midrapidity (${|y|<0.5}$) as a function of multiplicity in
$\sqrt{s}~=~7~\textrm{TeV}$ pp collisions are reported. Transverse momentum
distributions and integrated yields are compared to expectations from
statistical hadronization models along with results from different colliding
systems and center-of-mass energies. The evolution of spectral shapes with
multiplicity show similar patterns to those seen in p-Pb and Pb-Pb collisions.
The $p_{\textrm{T}}$-integrated baryon yields relative to pions exhibit a
significant strangeness-related enhancement in both pp and p-Pb collisions.


title: Did the Train Reach its Destination: The Complexity of Finding a Witness

abstract:
  Recently, Dohrau et al. studied a zero-player game on switch graphs and
proved that deciding the termination of the game is in NP $\cap$ coNP. In this
short paper, we show that the search version of this game on switch graphs,
i.e., the task of finding a witness of termination (or of non-termination) is
in PLS.


title:
A two-way model for nonlinear acoustic waves in a non-uniform lattice of
  Helmholtz resonators

abstract:
  Propagation of high amplitude acoustic pulses is studied in a 1D waveguide
connected to a lattice of Helmholtz resonators. An homogenized model has been
proposed by Sugimoto (J. Fluid. Mech., \textbf{244} (1992)), taking into
account both the nonlinear wave propagation and various mechanisms of
dissipation. This model is extended here to take into account two important
features: resonators of different strengths and back-scattering effects. An
energy balance is obtained, and a numerical method is developed. A closer
agreement is reached between numerical and experimental results. Numerical
experiments are also proposed to highlight the effect of defects and of
disorder.


title:
Search for a Metallic Dangling-Bond Wire on $n$-doped H-passivated
  Semiconductor Surfaces

abstract:
  We have theoretically investigated the electronic properties of neutral and
$n$-doped dangling bond (DB) quasi-one-dimensional structures (lines) in the
Si(001):H and Ge(001):H substrates with the aim of identifying atomic-scale
interconnects exhibiting metallic conduction for use in on-surface circuitry.
Whether neutral or doped, DB lines are prone to suffer geometrical distortions
or have magnetic ground-states that render them semiconducting. However, from
our study we have identified one exception -- a dimer row fully stripped of
hydrogen passivation. Such a DB-dimer line shows an electronic band structure
which is remarkably insensitive to the doping level and, thus, it is possible
to manipulate the position of the Fermi level, moving it away from the gap.
Transport calculations demonstrate that the metallic conduction in the DB-dimer
line can survive thermally induced disorder, but is more sensitive to imperfect
patterning. In conclusion, the DB-dimer line shows remarkable stability to
doping and could serve as a one-dimensional metallic conductor on $n$-doped
samples.


title: A study of the circum-galactic medium at z ~ 0.6 using DLA-galaxies

abstract:
  We present the study of a sample of nine QSO fields, with damped-Ly-alpha
(DLA) or sub-DLA systems at z~0.6, observed with the X-Shooter spectrograph at
the Very Large Telescope. By suitably positioning the X-Shooter slit based on
high spatial resolution images of HST/ACS we are able to detect absorbing
galaxies in 7 out of 9 fields (~ 78\% success rate) at impact parameters from
10 to 30 kpc. In 5 out of 7 fields the absorbing galaxies are confirmed via
detection of multiple emission lines at the redshift of DLAs where only 1 out
of 5 also emits a faint continuum. In 2 out of these 5 fields we detect a
second galaxy at the DLA redshift. Extinction corrected star formation rates
(SFR) of these DLA-galaxies, estimated using their H-alpha fluxes, are in the
range 0.3-6.7 M_sun yr^-1. The emission metallicities of these five
DLA-galaxies are estimated to be from 0.2 to 0.9 Z_sun. Based on the Voigt
profile fits to absorption lines we find the metallicity of the absorbing
neutral gas to be in a range of 0.05--0.6 Z_sun. The two remaining DLA-galaxies
are quiescent galaxies with SFR < 0.4 M_sun yr^-1 (3-sigma) presenting
continuum emission but weak or no emission lines. Using X-Shooter spectrum we
estimate i-band absolute magnitude of -19.5+/-0.2 for both these DLA-galaxies
that indicates they are sub-L* galaxies. Comparing our results with that of
other surveys in the literature we find a possible redshift evolution of the
SFR of DLA-galaxies.


title: Blow ups and base changes of symmetric powers and Chow groups

abstract:
  Let $\Sym^m X$ denote the $m$-th symmetric power of a smooth projective curve
$X$. Let $\wt{\Sym^m X}$ be the blow up of $\Sym^m X$ along some non-singular
subvariety. In this note we are going to discuss when the pushforward
homomorphism induced by the natural morphism from $\wt{\Sym^m X}$ to $\Sym^n X$
is injective at the level of Chow groups for $m\leq n$. Also we are going to
prove that base changes of embeddings of one symmetric power into another, with
respect to closed embeddings induces an injection at the level of Chow groups.


title:
Purification of recombinant human and Drosophila septin hexamers for
  TIRF assays of actin-septin filament assembly

abstract:
  Septins are guanine nucleotide-binding proteins that are conserved from fungi
to humans. Septins assemble into heterooligomeric complexes and higher-order
structures with key roles in various cellular functions including cell
migration and division. The mechanisms by which septins assemble and interact
with other cytoskeletal elements like actin remain elusive. A powerful approach
to address this question is by cell-free reconstitution of pu- rified
cytoskeletal proteins combined with fluorescence microscopy. Here, we describe
procedures for the purification of recombinant Drosophila and human septin
hexamers from Escherichia coli and reconstitution of actin-septin coassembly.
These procedures can be used to compare assembly of Drosophila and human
septins and their coassembly with the actin cytoskeleton by total internal
reflection fluorescence microscopy.


title:
Cyclic asymptotic behaviour of a population reproducing by fission into
  two equal parts

abstract:
  We study the asymptotic behaviour of the following linear
growth-fragmentation equation$$\dfrac{\partial}{\partial t} u(t,x) +
\dfrac{\partial}{\partial x} \big(x u(t,x)\big) + B(x) u(t,x) =4
B(2x)u(t,2x),$$ and prove that under fairly general assumptions on the division
rate $B(x),$ its solution converges towards an oscillatory function,explicitely
given by the projection of the initial state on the space generated by the
countable set of the dominant eigenvectors of the operator. Despite the lack of
hypo-coercivity of the operator, the proof relies on a general relative entropy
argument in a convenient weighted $L^2$ space, where well-posedness is obtained
via semigroup analysis. We also propose a non-dissipative numerical scheme,
able to capture the oscillations.


title:
Instrumenting an SMT Solver to Solve Hybrid Network Reachability
  Problems

abstract:
  PDDL+ planning has its semantics rooted in hybrid automata (HA) and recent
work has shown that it can be modeled as a network of HAs. Addressing the
complexity of nonlinear PDDL+ planning as HAs requires both space and time
efficient reasoning. Unfortunately, existing solvers either do not address
nonlinear dynamics or do not natively support networks of automata.
  We present a new algorithm, called HNSolve, which guides the variable
selection of the dReal Satisfiability Modulo Theories (SMT) solver while
reasoning about network encodings of nonlinear PDDL+ planning as HAs. HNSolve
tightly integrates with dReal by solving a discrete abstraction of the HA
network. HNSolve finds composite runs on the HA network that ignore continuous
variables, but respect mode jumps and synchronization labels. HNSolve
admissibly detects dead-ends in the discrete abstraction, and posts conflict
clauses that prune the SMT solver's search. We evaluate the benefits of our
HNSolve algorithm on PDDL+ benchmark problems and demonstrate its performance
with respect to prior work.


title:
Modified scattering and beating effect for coupled Schr\"odinger systems
  on product spaces with small initial data

abstract:
  In this paper, we study a coupled nonlinear Schr\"odinger system with small
initial data in a product space. We establish a modified scattering of the
solutions of this system and we construct a modified wave operator. The study
of the resonant system, which provides the asymptotic dynamics, allows us to
highlight a control of the Sobolev norms and interesting dynamics with the
beating effect. The proof uses a recent work of Hani, Pausader, Tzvetkov and
Visciglia for the modified scattering, and a recent work of Gr\'ebert, Paturel
and Thomann for the study of the resonant system.


title: Equidistribution of jellium energy for Coulomb and Riesz Interactions

abstract:
  For general dimension $d$ we prove the equidistribution of energy at the
micro-scale in $\mathbb R^d$, for the optimal point configurations appearing in
Coulomb gases at zero temperature. At the microscopic scale, i.e. after blow-up
at the scale corresponding to the interparticle distance, in the case of
Coulomb gases we show that the energy concentration is precisely determined by
the macroscopic density of points, independently of the scale. This uses the
"jellium energy" which was previously shown to control the next-order term in
the large particle number asymptotics of the minimum energy. As a corollary, we
obtain sharp error bounds on the discrepancy between the number of points and
its expected average of optimal point configurations for Coulomb gases,
extending previous results valid only for $2$-dimensional log-gases. For Riesz
gases with interaction potentials $g(x)=|x|^{-s}, s\in]\min\{0,d-2\},d[$ and
one-dimensional log-gases, we prove the same equidistribution result under an
extra hypothesis on the decay of the localized energy, which we conjecture to
hold for minimizing configurations. In this case we use the
Caffarelli-Silvestre description of the non-local fractional Laplacians in
$\mathbb R^d$ to localize the problem.


title: A Frequency Space for the Heisenberg Group

abstract:
  We here revisit Fourier analysis on the Heisenberg group H^d. Whereas,
according to the standard definition, the Fourier transform of an integrable
function f on H^d is a one parameter family of bounded operators on L 2 (R^d),
we define (by taking advantage of basic properties of Hermite functions) the
Fourier transform f\_H of f to be a uniformly continuous mapping on the set N^d
x N^d xR \ {0} endowed with a suitable distance. This enables us to extend f\_H
to the completion of that space, and to get an explicit asymptotic description
of the Fourier transform when the 'vertical' frequency tends to 0. We expect
our approach to be relevant for adapting to the Heisenberg framework a number
of classical results for the Euclidean case that are based on Fourier analysis.
As an example, we here establish an explicit extension of the Fourier transform
for smooth functions on H^d that are independent of the vertical variable.


title:
Immersed Boundary Smooth Extension (IBSE): A high-order method for
  solving incompressible flows in arbitrary smooth domains

abstract:
  The Immersed Boundary method is a simple, efficient, and robust numerical
scheme for solving PDE in general domains, yet for fluid problems it only
achieves first-order spatial accuracy near embedded boundaries for the velocity
field and fails to converge pointwise for elements of the stress tensor. In a
previous work we introduced the Immersed Boundary Smooth Extension (IBSE)
method, a variation of the IB method that achieves high-order accuracy for
elliptic PDE by smoothly extending the unknown solution of the PDE from a given
smooth domain to a larger computational domain, enabling the use of simple
Cartesian-grid discretizations. In this work, we extend the IBSE method to
allow for the imposition of a divergence constraint, and demonstrate high-order
convergence for the Stokes and incompressible Navier-Stokes equations: up to
third-order pointwise convergence for the velocity field, and second-order
pointwise convergence for all elements of the stress tensor. The method is
flexible to the underlying discretization: we demonstrate solutions produced
using both a Fourier spectral discretization and a standard second-order
finite-difference discretization.


title: Turbulent chimeras in large semiconductor laser arrays

abstract:
  Semiconductor laser arrays have been investigated experimentally and
theoretically from the viewpoint of temporal and spatial coherence for the past
forty years. In this work, we are focusing on a rather novel complex collective
behavior, namely chimera states, where synchronized clusters of emitters
coexist with unsynchronized ones. For the first time, we find such states exist
in large diode arrays based on quantum well gain media with nearest-neighbor
interactions. The crucial parameters are the evanescent coupling strength and
the relative optical frequency detuning between the emitters of the array. By
employing a recently proposed figure of merit for classifying chimera states,
we provide quantitative and qualitative evidence for the observed dynamics. The
corresponding chimeras are identified as turbulent according to the irregular
temporal behavior of the classification measure.


title:
Simultaneous high-speed internal and external flow measurements for a
  high-pressure diesel nozzle

abstract:
  We present an extensive experimental study focused on understanding the
impact of cavitation in a high-pressure diesel nozzle on the macroscopic
properties of fuel spray. Several high-speed videos of the liquid flow through
a transparent, asymmetric cylindrical nozzle with a single orifice (phi = 0.35
mm) are recorded along with the videos of the resulting spray in the
near-nozzle region, issued with an injection pressure of 300 bar at a
frame-rate of 75 kHz. The high-repetition images of the internal flow are then
used to estimate the onset of cavitation inside the transparent nozzle and the
probability of development of cavitation in different regions of the nozzle
with an average estimate of the amount of cavitation with time. On the other
hand, recorded spray images are used to study spray penetration, cone-angles
and velocity from the start of fuel injection. A novel approach is proposed for
the measurement of perturbations that occur in form of big liquid structures
along the spray boundary.