title:
A two-scale approach for efficient on-the-fly operator assembly in
  massively parallel high performance multigrid codes

abstract:
  Matrix-free finite element implementations of massively parallel geometric
multigrid save memory and are often significantly faster than implementations
using classical sparse matrix techniques. They are especially well suited for
hierarchical hybrid grids on polyhedral domains. In the case of constant
coefficients all fine grid node stencils in the interior of a coarse macro
element are equal. However, for non-polyhedral domains the situation changes.
Then even for the Laplace operator, the non-linear element mapping leads to
fine grid stencils that can vary from grid point to grid point. This
observation motivates a new two-scale approach that exploits a piecewise
polynomial approximation of the fine grid operator with respect to the coarse
mesh size. The low-cost evaluation of these surrogate polynomials results in an
efficient stencil assembly on-the-fly for non-polyhedral domains that can be
significantly more efficient than matrix-free techniques that are based on an
element-wise assembly. The performance analysis and additional hardware-aware
code optimizations are based on the Execution-Cache-Memory model. Several
aspects such as two-scale a priori error bounds and double discretization
techniques are presented. Weak and strong scaling results illustrate the
benefits of the new technique when used within large scale PDE solvers.


title: Hamiltonian circle actions with fixed point set almost minimal

abstract:
  Motivated by recent works on Hamiltonian circle actions satisfying certain
minimal conditions, in this paper, we consider Hamiltonian circle actions
satisfying an almost minimal condition. More precisely, we consider a compact
symplectic manifold $(M, \omega)$ admitting a Hamiltonian circle action with
fixed point set consisting of two connected components $X$ and $Y$ satisfying
$\dim(X)+\dim(Y)=\dim(M)$. Under certain cohomology conditions, we determine
the circle action, the integral cohomology rings of $M$, $X$ and $Y$, and the
total Chern classes of $M$, $X$, $Y$, and of the normal bundles of $X$ and $Y$.
The results show that these data are unique --- they are exactly the same as
those in the standard example $\Gt_2(\R^{2n+2})$, the Grassmannian of oriented
$2$-planes in $\R^{2n+2}$, which is of dimension $4n$ with (any) $n\in\N$,
equipped with a standard circle action. Moreover, if $M$ is K\"ahler and the
action is holomorphic, we can use a few different criteria to claim that $M$ is
$S^1$-equivariantly biholomorphic and $S^1$-equivariantly symplectomorphic to
$\Gt_2(\R^{2n+2})$.


title: Stabilization Control for Linear Continuous-time Mean-field Systems

abstract:
  This paper investigates the stabilization and control problems for linear
continuous-time mean-field systems (MFS). Under standard assumptions, necessary
and sufficient conditions to stabilize the mean-field systems in the mean
square sense are explored for the first time. It is shown that, under the
assumption of exact detectability (exact observability), the mean-field system
is stabilizable if and only if a coupled algebraic Riccati equation (ARE)
admits a unique positive semi-definite solution (positive definite solution),
which coincides with the classical stabilization results for standard
deterministic systems and stochastic systems.
  One of the key techniques in the paper is the obtained solution to the
forward and backward stochastic differential equation (FBSDE) associated with
the maximum principle for an optimal control problem. Actually, with the
analytical FBSDE solution, a necessary and sufficient solvability condition of
the optimal control, under mild conditions, is derived. Accordingly, the
stabilization condition is presented by defining an Lyaponuv functional via the
solution to the FBSDE and the optimal cost function.
  It is worth of pointing out that the presented results are different from the
previous works for stabilization and also different from the works on optimal
control.


title:
Identifying stochastic oscillations in single-cell live imaging time
  series using Gaussian processes

abstract:
  Multiple biological processes are driven by oscillatory gene expression at
different time scales. Pulsatile dynamics are thought to be widespread, and
single-cell live imaging of gene expression has lead to a surge of dynamic,
possibly oscillatory, data for different gene networks. However, the regulation
of gene expression at the level of an individual cell involves reactions
between finite numbers of molecules, and this can result in inherent randomness
in expression dynamics, which blurs the boundaries between aperiodic
fluctuations and noisy oscillators. Thus, there is an acute need for an
objective statistical method for classifying whether an experimentally derived
noisy time series is periodic. Here we present a new data analysis method that
combines mechanistic stochastic modelling with the powerful methods of
non-parametric regression with Gaussian processes. Our method can distinguish
oscillatory gene expression from random fluctuations of non-oscillatory
expression in single-cell time series, despite peak-to-peak variability in
period and amplitude of single-cell oscillations. We show that our method
outperforms the Lomb-Scargle periodogram in successfully classifying cells as
oscillatory or non-oscillatory in data simulated from a simple genetic
oscillator model and in experimental data. Analysis of bioluminescent live cell
imaging shows a significantly greater number of oscillatory cells when
luciferase is driven by a {\it Hes1} promoter (10/19), which has previously
been reported to oscillate, than the constitutive MoMuLV 5' LTR (MMLV) promoter
(0/25). The method can be applied to data from any gene network to both
quantify the proportion of oscillating cells within a population and to measure
the period and quality of oscillations. It is publicly available as a MATLAB
package.


title: Radiation from structured-ring resonators

abstract:
  We investigate the scalar-wave resonances of systems composed of identical
Neumann-type inclusions arranged periodically around a circular ring. Drawing
on natural similarities with the undamped Rayleigh-Bloch waves supported by
infinite linear arrays, we deduce asymptotically the exponentially small
radiative damping in the limit where the ring radius is large relative to the
periodicity. In our asymptotic approach, locally linear Rayleigh-Bloch waves
that attenuate exponentially away from the ring are matched to a ring-scale
WKB-type wave field. The latter provides a descriptive physical picture of how
the mode energy is transferred via tunnelling to a circular
evanescent-to-propagating transition region a finite distance away from the
ring, from where radiative grazing rays emanate to the far field. Excluding the
zeroth-order standing-wave modes, the position of the transition circle
bifurcates with respect to clockwise and anti-clockwise contributions,
resulting in striking spiral wavefronts.


title:
The expansion of polynomial invariants for $2$-decompositions of
  generalized graphs

abstract:
  The $2$-decomposition for ribbon graphs was introduced in [Annals of
Combinatorics 15 (2011), pp 675-706]. We extend this result to half-edged
ribbon graphs and to rank $D$-weakly colored graphs [SIGMA 12 (2016), 030],
generalizing therefore the $2$-sums and tensor products of these graphs. Using
this extension for the $2$-decompositions, we provide new expansion formulas
for the Bollob\'as Riordan polynomial for half-edged ribbon graphs and also for
the polynomial invariant for weakly colored stranded graphs.


title: Quantum Mechanics of a Photon

abstract:
  A first quantized free photon is a complex massless vector field $A=(A^\mu)$
whose field strength satisfies Maxwell's equations in vacuum. We construct the
Hilbert space $\mathscr{H}$ of the photon by endowing the vector space of the
fields $A$ in the temporal-Coulomb gauge with a positive-definite and
relativistically invariant inner product. We give an explicit expression for
this inner product, identify the Hamiltonian for the photon with the generator
of time translations in $\mathscr{H}$, determine the operators representing the
momentum and the helicity of the photon, and introduce a chirality operator
whose eigenfunctions correspond to fields having a definite sign of energy. We
also construct a position operator for the photon whose components commute with
each other and with the chirality and helicity operators. This allows for the
construction of the localized states of the photon with a definite sign of
energy and helicity. We derive an explicit formula for the latter and compute
the corresponding electric and magnetic fields. These turn out to diverge not
just at the point where the photon is localized but on a plane containing this
point. We identify the axis normal to this plane with an associated symmetry
axis, and show that each choice of this axis specifies a particular position
operator, a corresponding position basis, and a position representation of the
quantum mechanics of photon. In particular, we examine the position wave
functions determined by such a position basis, elucidate their relationship
with the Riemann-Silberstein and Landau-Peierls wave functions, and give an
explicit formula for the probability density of the spatial localization of the
photon.


title:
Isotopic ratios at z=0.68 from molecular absorption lines toward B
  0218+357

abstract:
  Isotopic ratios of heavy elements are a key signature of the nucleosynthesis
processes in stellar interiors. The contribution of successive generations of
stars to the metal enrichment of the Universe is imprinted on the evolution of
isotopic ratios over time. We investigate the isotopic ratios of carbon,
nitrogen, oxygen, and sulfur through millimeter molecular absorption lines
arising in the z=0.68 absorber toward the blazar B 0218+357. We find that these
ratios differ from those observed in the Galactic interstellar medium, but are
remarkably close to those in the only other source at intermediate redshift for
which isotopic ratios have been measured to date, the z=0.89 absorber in front
of PKS1830-211. The isotopic ratios in these two absorbers should reflect
enrichment mostly from massive stars, and they are indeed close to the values
observed toward local starburst galaxies. Our measurements set constraints on
nucleosynthesis and chemical evolution models.


title: Superintegrability of Geodesic Motion on the Sausage Model

abstract:
  Reduction of the $\eta$-deformed sigma model on ${\rm AdS}_5 \times {\rm
S}^5$ to the two-dimensional squashed sphere $({\rm S}^2)_{\eta}$ can be viewed
as a special case of the Fateev sausage model where the coupling constant $\nu$
is imaginary. We show that geodesic motion in this model is described by a
certain superintegrable mechanical system with four-dimensional phase space.
This is done by means of explicitly constructing three integrals of motion
which satisfy the $\mathfrak{sl}(2)$ Poisson algebra relations, albeit being
non-polynomial in momenta. Further, we find a canonical transformation which
transforms the Hamiltonian of this mechanical system to the one describing the
geodesic motion on the usual two-sphere. By inverting this transformation we
map geodesics on this auxiliary two-sphere back to the sausage model. This
paper is a tribute to the memory of Prof. Petr Kulish.


title: Coherent manipulation of single electron spins with Landau-Zener sweeps

abstract:
  We propose a novel method to manipulate the state of a single electron spin
in a semiconductor quantum dot (QD). The manipulation is achieved by tunnel
coupling a QD, labeled $L$, and occupied with an electron to an adjacent QD,
labeled $R$, which is not occupied by an electron but having an energy linearly
varying in time. We identify a parameter regime in which a complete population
transfer between the spin eigenstates $|L\uparrow\rangle$ and
$|L\downarrow\rangle$ is achieved without occupying the adjacent QD. This
method is convenient due to the fact that manipulation can be done
electrically, without the precise knowledge of the spin resonance condition,
and is robust against Zeeman level broadening caused by nuclear spins.


title: The Sloan Digital Sky Survey Quasar Catalog: twelfth data release

abstract:
  We present the Data Release 12 Quasar catalog (DR12Q) from the Baryon
Oscillation Spectroscopic Survey (BOSS) of the SDSS-III. This catalog includes
all SDSS-III/BOSS objects that were spectroscopically targeted as quasar
candidates during the full survey and that are confirmed as quasars via visual
inspection of the spectra, have luminosities Mi[z=2]<-20.5 (in a LCDM cosmology
with H_0 = 70 km/s/Mpc, Omega_M = 0.3, and Omega _L=0.7), and either display at
least one emission line with a full width at half maximum (FWHM)larger than 500
km/s or, if not, have interesting/complex absorption features. The catalog also
includes previously known quasars (mostly from SDSS-I and II) that were
reobserved by BOSS. The catalog contains 297,301 quasars detected over 9,376
square degrees with robust identification and redshift measured by a
combination of principal component eigenspectra. The number of quasars with
z>2.15 is about an order of magnitude greater than the number of z>2.15 quasars
known prior to BOSS. Redshifts and FWHMs are provided for the strongest
emission lines (CIV, CIII], MgII). The catalog identifies 29,580 broad
absorption line quasars and lists their characteristics. For each object, the
catalog presents five-band (u, g, r, i, z) CCD-based photometry together with
some information on the optical morphology and the selection criteria. When
available, the catalog also provides information on the optical variability of
quasars using SDSS and PTF multi-epoch photometry. The catalog also contains
X-ray, ultraviolet, near-infrared, and radio emission properties of the
quasars, when available, from other large-area surveys. The calibrated digital
spectra, covering the wavelength region 3,600-10,500A at a spectral resolution
in the range 1,300<R<2,500, can be retrieved from the SDSS Catalog Archive
Server.


title:
Measurements of the absolute branching fractions for
  $D_{s}^{+}\rightarrow\eta e^{+}\nu_{e}$ and
  $D_{s}^{+}\rightarrow\eta^{\prime} e^{+}\nu_{e}$

abstract:
  By analyzing 482 pb$^{-1}$ of $e^+e^-$ collision data collected at $\sqrt
s=4.009$ GeV with the BESIII detector at the BEPCII collider, we measure the
absolute branching fractions for the semileptonic decays $D_{s}^{+}\to\eta
e^{+}\nu_{e}$ and $D_{s}^{+}\to \eta'e^{+}\nu_{e}$ to be
${B}(D_{s}^{+}\rightarrow\eta e^{+}\nu_{e})=(2.30\pm0.31\pm0.08)$\% and
${B}(D_{s}^{+}\rightarrow\eta'e^{+} \nu_{e}) = (0.93\pm0.30\pm0.05)$\%,
respectively, and their ratio
$\frac{{B}(D_{s}^{+}\rightarrow\eta'e^{+}\nu_{e})}
{{B}(D_{s}^{+}\rightarrow\eta e^{+}\nu_{e})}=0.40\pm0.14\pm0.02$, where the
first uncertainties are statistical and the second ones are systematic. The
results are in good agreement with previous measurements within uncertainties;
they can be used to determine the $\eta-\eta'$ mixing angle and improve upon
the $D_s^+$ semileptonic branching ratio precision.


title: Fundamental properties of resonances

abstract:
  All resonances, from hydrogen nuclei excited by the high-energy gamma rays in
deep space to newly discovered particles produced in Large Hadron Collider,
should be described by the same fundamental physical quantities. However, two
distinct sets of properties are used to describe resonances: the pole
parameters (complex pole position and residue) and the Breit-Wigner parameters
(mass, width, and branching fractions). There is an ongoing decades-old debate
on which of them should be abandoned. In this study of nucleon resonances
emerging in the elastic pion-nucleon scattering we discover an intricate
interplay of the parameters from both sets, and realize that neither set is
completely independent or fundamental on its own.


title:
Search for a narrow baryonic state decaying to $pK^S_0$ and
  $\bar{p}K^S_0$ in deep inelastic scattering with the HERA II data

abstract:
  This paper presents the result of a search for a narrow strange baryonic
state in the invariant-mass distribution of $pK^0_S(\overline{p}K^0_S)$ in HERA
II data (2003-2007). The search was performed in the deep inelastic scattering
(DIS) data with photon virtuality, $Q^2$, between 20 and 100 GeV. The analysis
in HERA II period has improvements over the previous ZEUS analysis in HERA I
period (1996-2000). These consist of large statistics and improved particle
identification performance by using both of the CTD $dE/dx$ and the MVD $dE/dx$
in this search. Contrary to evidence for such an exotic state around 1.52 GeV
in the HERA I data, no such state is found in this analysis. The upper limits
on the production cross section are set at 95% confidence level.


title: Upsilon production in U+U collisions at 193 GeV with the STAR experiment

abstract:
  We present a measurement of the inclusive production of Upsilon mesons in U+U
collisions at 193 GeV at mid-rapidity (|y| < 1). Previous studies in central
Au+Au collisions at 200 GeV show a suppression of Upsilon(1S+2S+3S) production
relative to expectations from the Upsilon yield in p+p collisions scaled by the
number of binary nucleon-nucleon collisions (Ncoll), with an indication that
the Upsilon(1S) state is also suppressed. The present measurement extends the
number of participant nucleons in the collision (Npart) by 20% compared to
Au+Au collisions, and allows us to study a system with higher energy density.
We observe a suppression in both the Upsilon(1S+2S+3S) and Upsilon(1S) yields
in central U+U data, which consolidates and extends the previously observed
suppression trend in Au+Au collisions.


title:
A Photometric Study of Four Recently Discovered Contact Binaries: 1SWASP
  J064501.21+342154.9, 1SWASP J155822.10-025604.8, 1SWASP J212808.86+151622.0
  and UCAC4 436-062932

abstract:
  We present new, high-quality multicolor observations of four recently
discovered contact binaries: 1SWASP J064501.21+342154.9, 1SWASP
J155822.10-025604.8, 1SWASP J212808.86+151622.0, and UCAC4 436-062932, and
analyze their light curves to determine orbital and physical parameters using
the modeling program of G. Djura\v{s}evi\'c. In the absence of spectroscopic
observations, the effective temperatures of the brighter components are
estimated from the color indices, and the mass ratios are determined with the
q-search method. The analysis shows that all four systems are W UMa type
binaries in shallow contact configurations, consisting of late-type
main-sequence primaries and evolved secondaries with active surface regions
(dark or bright spots) resulting from magnetic activity or ongoing transfer of
thermal energy between the components. We compare the derived orbital and
stellar parameters for these four variables with a large sample of previously
analyzed W UMa stars and find that our results fit it well.


title:
Towards an automatic system for monitoring of CN2 and wind speed
  profiles with GeMS

abstract:
  Wide Field Adaptive Optics (WFAO) systems represent the more sophisticated AO
systems available today at large telescopes. A critical aspect for these WFAO
systems in order to deliver an optimised performance is the knowledge of the
vertical spatiotemporal distribution of the CN2 and the wind speed. Previous
studies (Cortes et al., 2012) already proved the ability of GeMS (the Gemini
Multi-Conjugated AO system) in retrieving CN2 and wind vertical stratification
using the telemetry data. To assess the reliability of the GeMS wind speed
estimates a preliminary study (Neichel et al., 2014) compared wind speed
retrieved from GeMS with that obtained with the atmospherical model Meso-Nh on
a small sample of nights providing promising results. The latter technique is
very reliable for the wind speed vertical stratification. The model outputs
gave, indeed, an excellent agreement with a large sample of radiosoundings (~
50) both in statistical terms and on individual flights (Masciadri et al.,
2013). Such a tool can therefore be used as a valuable reference in this
exercise of cross calibrating GeMS on-sky wind estimates with model
predictions. In this contribution we achieved a two-fold results: (1) we
extended analysis on a much richer statistical sample (~ 43 nights), we
confirmed the preliminary results and we found an even better correlation
between GeMS observations and the atmospherical model with basically no cases
of not-negligible uncertainties; (2) we evaluate the possibility to use, as an
input for GeMS, the Meso-Nh estimates of the wind speed stratification in an
operational configuration. Under this configuration these estimates can be
provided many hours in advanced with respect to the observations and with a
very high temporal frequency (order of 2 minutes or less).


title:
SANS Study of Vortex Lattice Structural Transition in Optimally Doped
  (Ba$_{1-x}$K$_{x}$)Fe$_{2}$As$_{2}$

abstract:
  Small-angle neutron scattering on high quality single crystalline
Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$ reveals the transition from a low--field
vortex solid phase with orientational order to a vortex polycrystal at high
magnetic field. The vortex order-disorder transition is correlated with the
second-peak feature in isothermal hysteresis loops, and is interpreted in terms
of the generation of supplementary vortex solid dislocations. The sharp drop of
the structure factor above the second peak field is explained by the dynamics
of freezing of the vortex ensemble in the high field phase.


title: Delay Evaluation of OpenFlow Network Based on Queueing Model

abstract:
  As one of the most popular south-bound protocol of software-defined
networking(SDN), OpenFlow decouples the network control from forwarding
devices. It offers flexible and scalable functionality for networks. These
advantages may cause performance issues since there are performance penalties
in terms of packet processing speed. It is important to understand the
performance of OpenFlow switches and controllers for its deployments. In this
paper we model the packet processing time of OpenFlow switches and controllers.
We mainly analyze how the probability of packet-in messages impacts the
performance of switches and controllers. Our results show that there is a
performance penalty in OpenFlow networks. However, the penalty is not much when
probability of packet-in messages is low. This model can be used for a network
designer to approximate the performance of her deployments.


title: Multiple Infection Sources Identification with Provable Guarantees

abstract:
  Given an aftermath of a cascade in the network, i.e. a set $V_I$ of
"infected" nodes after an epidemic outbreak or a propagation of
rumors/worms/viruses, how can we infer the sources of the cascade? Answering
this challenging question is critical for computer forensic, vulnerability
analysis, and risk management. Despite recent interest towards this problem,
most of existing works focus only on single source detection or simple network
topologies, e.g. trees or grids.
  In this paper, we propose a new approach to identify infection sources by
searching for a seed set $S$ that minimizes the \emph{symmetric difference}
between the cascade from $S$ and $V_I$, the given set of infected nodes. Our
major result is an approximation algorithm, called SISI, to identify infection
sources \emph{without the prior knowledge on the number of source nodes}. SISI,
to our best knowledge, is the first algorithm with \emph{provable guarantee}
for the problem in general graphs. It returns a
$\frac{2}{(1-\epsilon)^2}\Delta$-approximate solution with high probability,
where $\Delta$ denotes the maximum number of nodes in $V_I$ that may infect a
single node in the network. Our experiments on real-world networks show the
superiority of our approach and SISI in detecting true source(s), boosting the
F1-measure from few percents, for the state-of-the-art NETSLEUTH, to
approximately 50\%.


title: Cosmology with moving bimetric fluids

abstract:
  We study cosmological implications of bigravity and massive gravity solutions
with non-simultaneously diagonal metrics by considering the generalized Gordon
and Kerr-Schild ansatzes. The scenario that we obtain is equivalent to that of
General Relativity with additional non-comoving perfect fluids. We show that
the most general ghost-free bimetric theory generates three kinds of effective
fluids whose equations of state are fixed by a function of the ansatz.
Different choices of such function allow to reproduce the behaviour of
different dark fluids. In particular, the Gordon ansatz is suitable for the
description of various kinds of slowly-moving fluids, whereas the Kerr-Schild
one is shown to describe a null dark energy component. The motion of those dark
fluids with respect to the CMB is shown to generate, in turn, a relative motion
of baryonic matter with respect to radition which contributes to the CMB
anisotropies. CMB dipole observations are able to set stringent limits on the
dark sector described by the effective bimetric fluid.


title:
Evolution and Statistics of Non-Sphericity of Dark Matter Halos from
  Cosmological N-Body Simulation

abstract:
  We revisit the non-sphericity of cluster-mass scale halos from cosmological
N-body simulation on the basis of triaxial modelling. In order to understand
the difference between the simulation results and the conventional ellipsoidal
collapse model (EC), we first consider the evolution of individual simulated
halos. The major difference between EC and the simulation becomes appreciable
after the turn-around epoch. Moreover, it is sensitive to the individual
evolution history of each halo. Despite such strong dependence on individual
halos, the resulting nonsphericity of halos exhibits weak but robust mass
dependence in a statistical fashion; massive halos are more spherical up to the
turn-around, but gradually become less spherical by z = 0. This is clearly
inconsistent with the EC prediction; massive halos are usually more spherical.
In addition, at z=0, inner regions of the halos are less spherical than outer
regions, i.e., the density distribution inside the halos is highly
inhomogeneous and therefore not self-similar. Since most of previous fitting
formulae for the PDF of axis ratio of triaxial ellipsoids have been constructed
under the self-similarity assumption, they are not accurate. Indeed, we compute
the PDF of projected axis ratio a1/a2 directly from the simulation data without
the self-similarity assumption, and find that it is very sensitive to the
assumption. The latter needs to be carefully taken into account in direct
comparison with observations, and therefore we provide an empirical fitting
formula for the PDF of a1/a2. Our preliminary analysis suggests that the
derived PDF of a1/a2 roughly agrees with the current weak-lensing observations.
More importantly, the present results will be useful in future exploration of
the non-sphericity of clusters in X-ray and optical observations.


title:
Searching Action Proposals via Spatial Actionness Estimation and
  Temporal Path Inference and Tracking

abstract:
  In this paper, we address the problem of searching action proposals in
unconstrained video clips. Our approach starts from actionness estimation on
frame-level bounding boxes, and then aggregates the bounding boxes belonging to
the same actor across frames via linking, associating, tracking to generate
spatial-temporal continuous action paths. To achieve the target, a novel
actionness estimation method is firstly proposed by utilizing both human
appearance and motion cues. Then, the association of the action paths is
formulated as a maximum set coverage problem with the results of actionness
estimation as a priori. To further promote the performance, we design an
improved optimization objective for the problem and provide a greedy search
algorithm to solve it. Finally, a tracking-by-detection scheme is designed to
further refine the searched action paths. Extensive experiments on two
challenging datasets, UCF-Sports and UCF-101, show that the proposed approach
advances state-of-the-art proposal generation performance in terms of both
accuracy and proposal quantity.


title: Optical frequency combs generated mechanically

abstract:
  It is shown that a highly equidistant optical frequency comb can be generated
by the parametric excitation of an optical bottle microresonator with nanoscale
effective radius variation by its natural mechanical vibrations.


title: On Tate duality and a projective scalar property for symmetric algebras

abstract:
  We identify a class of symmetric algebras over a complete discrete valuation
ring $\mathcal O$ of characteristic zero to which the characterisation of
Kn\"orr lattices in terms of stable endomorphism rings in the case of finite
group algebras, can be extended. This class includes finite group algebras,
their blocks and source algebras and Hopf orders. We also show that certain
arithmetic properties of finite group representations extend to this class of
algebras. Our results are based on an explicit description of Tate duality for
lattices over symmetric $\mathcal O$-algebras whose extension to the quotient
field of $\mathcal O$ is separable.


title: Fast binary embeddings with Gaussian circulant matrices: improved bounds

abstract:
  We consider the problem of encoding a finite set of vectors into a small
number of bits while approximately retaining information on the angular
distances between the vectors. By deriving improved variance bounds related to
binary Gaussian circulant embeddings, we largely fix a gap in the proof of the
best known fast binary embedding method. Our bounds also show that
well-spreadness assumptions on the data vectors, which were needed in earlier
work on variance bounds, are unnecessary. In addition, we propose a new binary
embedding with a faster running time on sparse data.


title: Dijkstra Monads for Free

abstract:
  Dijkstra monads enable a dependent type theory to be enhanced with support
for specifying and verifying effectful code via weakest preconditions. Together
with their closely related counterparts, Hoare monads, they provide the basis
on which verification tools like F*, Hoare Type Theory (HTT), and Ynot are
built.
  We show that Dijkstra monads can be derived "for free" by applying a
continuation-passing style (CPS) translation to the standard monadic
definitions of the underlying computational effects. Automatically deriving
Dijkstra monads in this way provides a correct-by-construction and efficient
way of reasoning about user-defined effects in dependent type theories.
  We demonstrate these ideas in EMF*, a new dependently typed calculus,
validating it via both formal proof and a prototype implementation within F*.
Besides equipping F* with a more uniform and extensible effect system, EMF*
enables a novel mixture of intrinsic and extrinsic proofs within F*.


title:
Accurate Measurements of Free Flight Drag Coefficients with Amateur
  Doppler Radar

abstract:
  In earlier papers, techniques have been described using optical chronographs
to determine free flight drag coefficients with an accuracy of 1-2%,
accomplished by measuring near and far velocities of projectiles in flight over
a known distance. Until recently, Doppler radar has been prohibitively
expensive for many users. This paper reports results of exploring potential
applications and accuracy using a recently available, inexpensive (< $600 US)
amateur Doppler radar system to determine drag coefficients for projectiles of
various sizes (4.4 mm to 9 mm diameter) and speeds (M0.3 to M3.0). In many
cases, drag coefficients can be determined with an accuracy of 1% or better if
signal-to-noise ratio is sufficient and projectiles vary little between trials.
It is also straightforward to design experiments for determining drag over a
wide range of velocities. Experimental approaches and limitations are
described. Overall, the amateur radar system shows greater accuracy, ease of
use, and simplicity compared with optical chronographs. Doppler radar has
advantages of working well with less accurate projectiles without putting
equipment at risk of projectile impact downrange. The system can also detect
phenomena that optical chronographs cannot, such as projectile instability
resulting in tumbling in flight. This technology may be useful in introductory
physics labs, aerodynamics labs, and for accurately determining drag and
ballistic coefficients of projectiles used in military, law enforcement, and
sporting applications. The most significant limitations are reduced
signal-to-noise with smaller projectiles (< 5 mm diameter) and inability to
detect projectiles more than 100 m down range.


title:
Screening limited switching performance of multilayer 2D semiconductor
  FETs: the case for SnS

abstract:
  Gate tunable p-type multilayer tin mono-sulfide (SnS) field-effect transistor
(FET) devices with SnS thickness between 50 and 100 nm were fabricated and
studied to understand their performances. The devices showed anisotropic
inplane conductance and room temperature field effect mobilities ~5 - 10
cm$^2$/Vs. However, the devices showed appreciable OFF state conductance and an
ON-OFF ratio ~10 at room temperature. The weak gate tuning behavior in the
depletion regime of SnS devices is explained by the finite carrier screening
length effect which causes the existence of a conductive surface layer from
intrinsic defects induced holes in SnS. Through etching and n-type surface
doping by Cs2CO3 to reduce/compensate the not-gatable holes near SnS flake's
top surface, the devices gained an order of magnitude improvement in the ON-OFF
ratio and hole Hall mobility ~ 100 cm$^2$/Vs at room temperature is observed.
This work suggests that in order to obtain effective switching and low OFF
state power consumption, two-dimensional (2D) semiconductor based depletion
mode FETs should limit their thickness to within the Debye screening length of
carriers in the semiconductor.


title: Coherent Cerenkov radiation and laser oscillation in a photonic crystal

abstract:
  We demonstrate that photonic crystals can be used to generate powerful and
highly coherent laser radiation when injecting a beam of free electrons. Using
theoretical investigations we present the startup dynamics and coherence
properties of such laser, in which gain is provided by matching the optical
phase velocity in the photonic crystal to the velocity of the electron beam.


title: Hadronic Lorentz Violation in Chiral Perturbation Theory

abstract:
  Any possible Lorentz violation in the hadron sector must be tied to Lorentz
violation at the underlying quark level. The relationships between the theories
at these two levels are studied using chiral perturbation theory. Starting from
a two-flavor quark theory that includes dimension-four Lorentz-violation
operators, the effective Lagrangians are derived for both pions and nucleons,
with novel terms appearing in both sectors. Since the Lorentz violation
coefficients for nucleons and pions are all related to a single set of
underlying quark coefficients, it is possible to place approximate bounds on
pion Lorentz violation using only proton and neutron observations. The
resulting bounds on four pion parameters are at the $10^{-23}$ level,
representing improvements of ten orders of magnitude.


title: Fast analytic solver of rational Bethe equations

abstract:
  In this note we propose an approach for a fast analytic determination of all
possible eigenstates of rational GL(N|M) integrable spin chains of given not
too large length, in terms of Baxter Q-functions. We observe that all
exceptional solutions, if any, are automatically correctly accounted.
  The key intuition behind the approach is that the equations on the
Q-functions are determined solely by the Young diagram, and not by the choice
of the rank of the GL symmetry. Hence we can choose arbitrary N and M that
accommodate the desired representation. Then we consider all distinguished
Q-functions at once, not only those following a certain Kac-Dynkin path.


title: On The Relationship Between Magnetic Cancellation and UV Burst Formation

abstract:
  Burst-like events with signatures in the UV are often observed co-spatial to
strong line-of-sight photospheric magnetic fields. Several authors, for
example, have noted the spatial relationship between Ellerman bombs (EBs) and
Moving Magnetic Features (MMFs), regions of flux which disconnect from a
sunspot or pore before propagating away in the moat flow and often displaying
evidence of cancellation. In this article, data collected by the Solar Dynamics
Observatory's Helioseismic and Magnetic Imager and Atmospheric Imaging Assembly
are analysed in an attempt to understand the potential links between such
cancellation and UV burst formation. Two MMFs from AR 11579, three bi-poles
from AR 11765, and six bi-poles (four of which were co-spatial to IRIS bursts)
in AR 11850 were identified for analysis. All of these cancellation features
were found to have lifetimes of the order hours and cancellation rates of the
order 10^14-10^15 Mx s^-1. H-alpha line wing data from the Dunn Solar
Telescope's Interferometric BIdimensional Spectrometer were also available for
AR 11579 facilitating a discussion of links between MMFs and EBs. Using an
algebraic model of photospheric magnetic reconnection, the measured
cancellation rates are then used to ascertain estimates of certain quantities
(such as up-flow speeds, jet extents, and potential energy releases) which
compared reasonably to the properties of EBs reported within the literature.
Our results suggest that cancellation rates of the order measured here are
capable of supplying enough energy to drive certain UV bursts (including EBs),
however, they are not a guaranteeing condition for burst formation.


title:
Operational optical turbulence forecast for the Service Mode of
  top-class ground based telescopes

abstract:
  In this contribution we present the most relevant results obtained in the
context of a feasibility study (MOSE) undertaken for ESO. The principal aim of
the project was to quantify the performances of a mesoscale model
(Astro-Meso-NH code) in forecasting all the main atmospherical parameters
relevant for the ground-based astronomical observations and the optical
turbulence (CN2 and associated integrated astroclimatic parameters) above Cerro
Paranal (site of the VLT) and Cerro Armazones (site of the E-ELT). A detailed
analysis on the score of success of the predictive capacities of the system
have been carried out for all the astroclimatic as well as for the
atmospherical parameters. Considering the excellent results that we obtained,
this study proved the opportunity to implement on these two sites an automatic
system to be run nightly in an operational configuration to support the
scheduling of scientific programs as well as of astronomical facilities
(particularly those supported by AO systems) of the VLT and the E-ELT. At the
end of 2016 a new project for the implementation of a demonstrator of an
operational system to be run on the two ESO's sites will start. Our team is
also responsible for the implementation of a similar automatic system at
Mt.Graham, site of the LBT (ALTA Project). Our system/method will permit
therefore to make a step ahead in the framework of the Service Mode for new
generation telescopes. Among the most exciting achieved results we cite the
fact that we proved to be able to forecast CN2 profiles with a vertical
resolution as high as 150 m. Such a feature is particularly crucial for all
WFAO systems that require such detailed information on the OT vertical
stratification on the whole 20 km above the ground. This important achievement
tells us that all the WFAO systems can rely on automatic systems that are able
to support their optimized use.


title: Representation stability for filtrations of Torelli groups

abstract:
  We show, finitely generated rational $\mathsf{VIC}_{\mathbb Q}$-modules and
$\mathsf{SI}_{\mathbb Q}$-modules are uniformly representation stable and all
their submodules are finitely generated. We use this to prove two conjectures
of Church and Farb, which state that the quotients of the lower central series
of the Torelli subgroups of $\mathrm{Aut}(F_n)$ and
$\mathrm{Mod}(\Sigma_{g,1})$ are uniformly representation stable as sequences
of representations of the general linear groups and the symplectic groups,
respectively. Furthermore we prove an analogous statement for their Johnson
filtrations.


title: Chirality oscillation of primordial gravitational waves during inflation

abstract:
  We show that if the gravitational Chern-Simons term couples to a massive
scalar field ($m>H$), the primordial gravitational waves (GWs) will show itself
the chirality oscillation, i.e., the amplitudes of the left- and right-handed
GWs modes will convert into each other and oscillate in their propagations.
This oscillation will eventually develop a permanent difference of the
amplitudes of both modes, which leads to nearly opposite oscillating shapes in
the power spectra of the left- and right-handed primordial GWs. We discuss its
implication to the CMB B-mode polarization.


title:
Does the particle creation mechanism favour the formation of a black
  hole or a naked singularity?

abstract:
  The paper deals with collapse dynamics of a spherically symmetric massive
star in the framework of non-equilibrium themodynamic prescription through
particle creation mechanism. The matter content in the star is in the form of
perfect uid with barotropic equation of state and the dissipative phenomena due
to non-equilibrium thermodynamics is in the form of bulk viscosity. For
simplicity, the thermodynamic system is chosen to be adiabatic (i.e.,
isentropic) so that the effective bulk viscous pressure is linearly related to
the particle creation rate. As a result, the evolution of the collapsing star
also depends on the particle creation rate. By proper choice of creation rate
as a function of the Hubble parameter, it is found that the end state of the
collapse may be either a black hole or a naked singularity.


title:
Adaptive Data Collection Mechanisms for Smart Monitoring of Distribution
  Grids

abstract:
  Smart Grid systems not only transport electric energy but also information
which will be active part of the electricity supply system. This has led to the
introduction of intelligent components on all layers of the electrical grid in
power generation, transmission, distribution and consumption units. For
electric distribution systems, Information from Smart Meters can be utilized to
monitor and control the state of the grid. Hence, it is indeed inherent that
data from Smart Meters should be collected in a resilient, reliable, secure and
timely manner fulfilling all the communication requirements and standards. This
paper presents a proposal for smart data collection mechanisms to monitor
electrical grids with adaptive smart metering infrastructures. A general
overview of a platform is given for testing, evaluating and implementing
mechanisms to adapt Smart Meter data aggregation. Three main aspects of
adaptiveness of the system are studied, adaptiveness to smart metering
application needs, adaptiveness to changing communication network dynamics and
adaptiveness to security attacks. Execution of tests will be conducted in real
field experimental set-up and in an advanced hardware in the loop test-bed with
power and communication co-simulation for validation purposes.


title: Wireless Sensor Networks: Local Multicast Study

abstract:
  Wireless sensor networks and Ad-hoc network in the region Multicast
(Geocasting) means to deliver the message to all nodes in a given geographical
area from the source point. Regional Multicast practical application of the
specified area and other regions may be formed to broadcast transmission and
location-related business information, extensive advertising, or to send an
urgent message. Regional multicast protocol design goal is to ensure messaging
and low transport costs. Most have been proposed agreement does not guarantee
message delivery, although some other guaranteed messaging protocol has
triggered high transmission costs. The goal now is to ensure that research
messaging and low-cost local transmission protocol and its algorithm, to
promote the development of domain communication. This paper introduces the
research background and research results, and proposed to solve the problems
and ideas.


title:
On the physical limitations for radio frequency absorption in gold
  nanoparticle suspensions

abstract:
  This paper presents a study on the physical limitations for radio frequency
absorption in gold nanoparticle suspensions. A canonical spherical geometry is
considered consisting of a spherical suspension of colloidal gold nanoparticles
characterized as an arbitrary passive dielectric material which is immersed in
an arbitrary lossy medium. A relative heating coefficient and a corresponding
optimal near field excitation are defined taking the skin effect of the
surrounding medium into account. For small particle suspensions the optimal
excitation is an electric dipole field for which explicit asymptotic
expressions are readily obtained. It is then proven that the optimal
permittivity function yielding a maximal absorption inside the spherical
suspension is a conjugate match with respect to the surrounding lossy material.
For a surrounding medium consisting of a weak electrolyte solution the optimal
conjugate match can then readily be realized at a single frequency, e.g., by
tuning the parameters of a Drude model corresponding to the electrophoretic
particle acceleration mechanism. As such, the conjugate match can also be
regarded to yield an optimal plasmonic resonance. Finally, a convex
optimization approach is used to investigate the realizability of a passive
material to approximate the desired conjugate match over a finite bandwidth.
The relation of the proposed approach to general Mie theory as well as to the
approximation of metamaterials are discussed. Numerical examples are included
to illustrate the ultimate potential of heating in a realistic scenario in the
microwave regime.


title: The nuclear and extended mid-infrared emission of Seyfert galaxies

abstract:
  We present subarcsecond resolution mid-infrared (MIR) images obtained with
8-10 m-class ground-based telescopes of a complete volume-limited (DL<40 Mpc)
sample of 24 Seyfert galaxies selected from the Swift/BAT nine month catalog.
We use those MIR images to study the nuclear and circumnuclear emission of the
galaxies. Using different methods to classify the MIR morphologies on scales of
~400 pc, we find that the majority of the galaxies (75-83%) are extended or
possibly extended and 17-25% are point-like. This extended emission is compact
and it has low surface brightness compared with the nuclear emission, and it
represents, on average, ~30% of the total MIR emission of the galaxies in the
sample. We find that the galaxies whose circumnuclear MIR emission is dominated
by star formation show more extended emission (650+-700 pc) than AGN-dominated
systems (300+-100 pc). In general, the galaxies with point-like MIR
morphologies are face-on or moderately inclined (b/a~0.4-1.0), and we do not
find significant differences between the morphologies of Sy1 and Sy2. We used
the nuclear and circumnuclear fluxes to investigate their correlation with
different AGN and SF activity indicators. We find that the nuclear MIR emission
(the inner ~70 pc) is strongly correlated with the X-ray emission (the harder
the X-rays the better the correlation) and with the [O IV] lambda 25.89 micron
emission line, indicating that it is AGN-dominated. We find the same results,
although with more scatter, for the circumnuclear emission, which indicates
that the AGN dominates the MIR emission in the inner ~400 pc of the galaxies,
with some contribution from star formation.


title:
Dynamic Multi-Objectives Optimization with a Changing Number of
  Objectives

abstract:
  Existing studies on dynamic multi-objective optimization focus on problems
with time-dependent objective functions, while the ones with a changing number
of objectives have rarely been considered in the literature. Instead of
changing the shape or position of the Pareto-optimal front/set when having
time-dependent objective functions, increasing or decreasing the number of
objectives usually leads to the expansion or contraction of the dimension of
the Pareto-optimal front/set manifold. Unfortunately, most existing dynamic
handling techniques can hardly be adapted to this type of dynamics. In this
paper, we report our attempt toward tackling the dynamic multi-objective
optimization problems with a changing number of objectives. We implement a new
two-archive evolutionary algorithm which maintains two co-evolving populations
simultaneously. In particular, these two populations are complementary to each
other: one concerns more about the convergence while the other concerns more
about the diversity. The compositions of these two populations are adaptively
reconstructed once the environment changes. In addition, these two populations
interact with each other via a mating selection mechanism. Comprehensive
experiments are conducted on various benchmark problems with a time-dependent
number of objectives. Empirical results fully demonstrate the effectiveness of
our proposed algorithm.


title:
Asymmetric structure in Sgr A* at 3mm from closure phase measurements
  with VLBA, GBT and LMT

abstract:
  We present the results of a closure phase analysis of 3 mm very long baseline
interferometry (VLBI) measurements performed on Sagittarius A* (Sgr A*). We
have analyzed observations made in May 2015 using the Very Long Baseline Array,
the Robert C. Byrd Green Bank Telescope and the Large Millimeter Telescope
Alfonso Serrano and obtained non-zero closure phase measurements on several
station triangles - indicative of a non-point-symmetric source structure. The
data are fitted with an asymmetric source structure model in Sgr A*,
represented by a simple two-component model, which favours a fainter component
due East of the main source. This result is discussed in light of a scattering
screen with substructure or an intrinsically asymmetric source.


title:
Predicting epidemic evolution on contact networks from partial
  observations

abstract:
  The massive employment of computational models in network epidemiology calls
for the development of improved inference methods for epidemic forecast. For
simple compartment models, such as the Susceptible-Infected-Recovered model,
Belief Propagation was proved to be a reliable and efficient method to identify
the origin of an observed epidemics. Here we show that the same method can be
applied to predict the future evolution of an epidemic outbreak from partial
observations at the early stage of the dynamics. The results obtained using
Belief Propagation are compared with Monte Carlo direct sampling in the case of
SIR model on random (regular and power-law) graphs for different observation
methods and on an example of real-world contact network. Belief Propagation
gives in general a better prediction that direct sampling, although the quality
of the prediction depends on the quantity under study (e.g. marginals of
individual states, epidemic size, extinction-time distribution) and on the
actual number of observed nodes that are infected before the observation time.


title:
Efficient implementation of RKN-type Fourier collocation methods for
  second-order differential equations

abstract:
  In this paper we discuss the efficient implementation of RKN-type Fourier
collocation methods, which are used when solving second-order differential
equations. The proposed implementation relies on an alternative formulation of
the methods and the blended formulation. The features and effectiveness of the
implementation are confirmed by the performance of the methods on two numerical
tests.


title: Radio follow-up of gravitational wave triggers during Advanced LIGO O1

abstract:
  We present radio follow-up observations carried out with the Karl G. Jansky
Very Large Array during the first observing run (O1) of the Advanced Laser
Interferometer Gravitational-wave Observatory (LIGO). A total of three
gravitational wave triggers were followed up during the ~4 months of O1, from
September 2015 to January 2016. Two of these triggers, GW150914 and GW151226,
are binary black hole merger events of high significance. A third trigger,
G194575, was subsequently declared as an event of no interest (i.e., a false
alarm). Our observations targeted selected optical transients identified by the
intermediate Palomar Transient Factory (iPTF) in the Advanced LIGO error
regions of the three triggers, and a limited region of the gravitational wave
localization area of G194575 not accessible to optical telescopes due to Sun
constraints, where a possible high-energy transient was identified. No
plausible radio counterparts to GW150914 and GW151226 were found, in agreement
with expectations for binary black hole mergers. We show that combining optical
and radio observations is key to identifying contaminating radio sources that
may be found in the follow-up of gravitational wave triggers, such as emission
associated to star formation and AGN. We discuss our results in the context of
the theoretical predictions for radio counterparts to gravitational wave
transients, and describe our future plans for the radio follow-up of Advanced
LIGO (and Virgo) triggers.


title:
A new ab initio approach to the development of high temperature super
  conducting materials

abstract:
  We review recent theoretical developments, which suggest that a set of shared
principles underpin macroscopic quantum phenomena observed in high temperature
super conducting materials, room temperature coherence in photosynthetic
processes and the emergence of long range order in biological structures. These
systems are driven by dissipative systems, which lead to fractal assembly and a
fractal network of charges (with associated quantum potentials) at the
molecular scale. At critical levels of charge density and fractal dimension,
individual quantum potentials merge to form a charged induced macroscopic
quantum potential, which act as a structuring force dictating long range order.
Whilst the system is only partially coherent (i.e. only the bosonic fields are
coherent), within these processes many of the phenomena associated with
standard quantum theory are recovered, with macroscopic quantum potentials and
associated forces having their equivalence in standard quantum mechanics. We
establish a testable hypothesis that the development of structures analogous to
those found in biological systems, which exhibit macroscopic quantum
properties, should lead to increased critical temperatures in high temperature
superconducting materials. If the theory is confirmed it opens up a new,
systematic, ab initio approach to the structural development of these types of
materials.


title: Robust Flows over Time: Models and Complexity Results

abstract:
  We study dynamic network flows with uncertain input data under a robust
optimization perspective. In the dynamic maximum flow problem, the goal is to
maximize the flow reaching the sink within a given time horizon $T$, while flow
requires a certain travel time to traverse an edge.
  In our setting, we account for uncertain travel times of flow. We investigate
maximum flows over time under the assumption that at most $\Gamma$ travel times
may be prolonged simultaneously due to delay. We develop and study a
mathematical model for this problem. As the dynamic robust flow problem
generalizes the static version, it is NP-hard to compute an optimal flow.
However, our dynamic version is considerably more complex than the static
version. We show that it is NP-hard to verify feasibility of a given candidate
solution. Furthermore, we investigate temporally repeated flows and show that
in contrast to the non-robust case (that is, without uncertainties) they no
longer provide optimal solutions for the robust problem, but rather yield a
worst case optimality gap of at least $T$. We finally show that the optimality
gap is at most $O(\eta k \log T)$, where $\eta$ and $k$ are newly introduced
instance characteristics and provide a matching lower bound instance with
optimality gap $\Omega(\log T)$ and $\eta = k = 1$. The results obtained in
this paper yield a first step towards understanding robust dynamic flow
problems with uncertain travel times.


title: Does V-NIR based Image Enhancement Come with Better Features?

abstract:
  Image enhancement using the visible (V) and near-infrared (NIR) usually
enhances useful image details. The enhanced images are evaluated by observers
perception, instead of quantitative feature evaluation. Thus, can we say that
these enhanced images using NIR information has better features in comparison
to the computed features in the Red, Green, and Blue color channels directly?
In this work, we present a new method to enhance the visible images using NIR
information via edge-preserving filters, and also investigate which method
performs best from a image features standpoint. We then show that our proposed
enhancement method produces more stable features than the existing
state-of-the-art methods.


title:
LO Peg: surface differential rotation, flares, and spot-topographic
  evolution

abstract:
  Using the wealth of ~24 yr multiband data, we present an in-depth study of
the star-spot cycles, surface differential rotations (SDR), optical flares,
evolution of star-spot distributions, and coronal activities on the surface of
young, single, main-sequence, ultrafast rotator (UFR) LO Peg. From the
long-term V -band photometry, we derive rotational period of LO Peg to be
0.4231 +/- 0.0001 d. Using the seasonal variations on the rotational period,
the SDR pattern is investigated, and shows a solar-like pattern of SDR. A
cyclic pattern with period of ~2.7 yr appears to be present in rotational
period variation. During the observations, 20 optical flares are detected with
a flare frequency of 1 flare per two days and with flare energy of 10^{31-34}
erg. The surface coverage of cool spots is found to be in the range of 9-26 per
cent. It appears that the high- and low-latitude spots are interchanging their
positions. Quasi-simultaneous observations in X-ray, UV, and optical
photometric bands show a signature of an excess of X-ray and UV activities in
spotted regions.


title: Towards Holographic Quantum Energy Teleportation

abstract:
  We propose a simplified protocol of quantum energy teleportation (QET) for
holographic conformal field theory (CFT) in 3-dimensional anti-de Sitter space
with or without black hole. As a tentative proposal, we simplify the standard
QET by replacing Alice's local measurement with the local projection, which
excites the system from ground state into a particular state dual to a Banados
geometry. We then mimic Bob's local operation of the usual QET for extracting
energy by deforming the UV surface with a local bump. Adopting the
surface/state duality this deformation corresponds to local unitary. We
evaluate the extraction of energy from the holographic stress tensor, and find
that Bob always gains energy extraction in our protocol. This could be related
to the positive energy theorem of the dual gravity. Moreover, the ratio of
extraction energy to injection one is a universal function of the UV surface
deformation profile.


title:
Exponential Fourier collocation methods for solving first-order
  differential equations

abstract:
  In this paper, a novel class of exponential Fourier collocation methods
(EFCMs) is presented for solving systems of first-order ordinary differential
equations. These so-called exponential Fourier collocation methods are based on
the variation-of-constants formula, incorporating a local Fourier expansion of
the underlying problem with collocation methods. We discuss in detail the
connections of EFCMs with trigonometric Fourier collocation methods (TFCMs),
the well-known Hamiltonian Boundary Value Methods (HBVMs), Gauss methods and
Radau IIA methods. It turns out that the novel EFCMs are an essential extension
of these existing methods. We also analyse the accuracy in preserving the
quadratic invariants and the Hamiltonian energy when the underlying system is a
Hamiltonian system. Other properties of EFCMs including the order of
approximations and the convergence of fixed-point iterations are investigated
as well. The analysis given in this paper proves further that EFCMs can achieve
arbitrarily high order in a routine manner which allows us to construct
higher-order methods for solving systems of first-order ordinary differential
equations conveniently. We also derive a practical fourth-order EFCM denoted by
EFCM(2,2) as an illustrative example. The numerical experiments using EFCM(2,2)
are implemented in comparison with an existing fourth-order HBVM, an
energy-preserving collocation method and a fourth-order exponential integrator
in the literature. The numerical results demonstrate the remarkable efficiency
and robustness of the novel EFCM(2,2).


title: Ground state energy density of the quantum harmonic oscillator

abstract:
  The total energy of the ground state of the quantum harmonic oscillator is
obtained with minimal assumptions. The vacuum energy density of the universe is
derived and a cutoff frequency is obtained for the upper bound of the quantum
harmonic oscillator.


title: Triggering filamentation using turbulence

abstract:
  We study the triggering of single filaments due to turbulence in the beam
path for a laser of power below the filamenting threshold. Turbulence can act
as a switch between the beam not filamenting and producing single filaments.
This 'positive' effect of turbulence on the filament probability, combined with
our observation of off-axis filaments suggests the underlying mechanism is
modulation instability caused by transverse perturbations. We hereby
experimentally explore the interaction of modulation instability and
turbulence, commonly associated with multiple-filaments, in the single-filament
regime.


title:
Fierz relations for Volkov spinors and the simplification of Furry
  picture traces

abstract:
  Transition probability calculations of strong field particle processes in the
Furry picture, typically use fermion Volkov solutions. These solutions have a
relatively complicated spinor due to the interaction of the electron spin with
a strong external field, which in turn leads to unwieldy trace calculations.
The simplification of these calculations would aid theoretical studies of
strong field phenomena such as the predicted resonance behaviour of higher
order Furry picture processes. Here, Fierz transformations of Volkov spinors
are developed and applied to a 1st order and a 2nd order Furry picture process.
Combined with symmetry properties, the techniques presented here are generally
applicable and lead to considerable simplification of Furry picture analytic
calculations.


title:
Bridge between Hadrodynamics & HEP: Regional CP Violation in Beauty &
  Charm Decays

abstract:
  There is a long way from `accuracy' to `precision' about {\bf CP} asymmetries
in the decays of beauty \& charm hadrons. (a) We have to apply consistent
parametrization of the CKM matrix. (b) Probing many-body final states (FS) is
{\em not} a back-up for understanding the underlying forces; to be realistic we
can hardly go beyond four-body FS. (c) Broken U-spin symmetry is a good tools
to describe spectroscopy of hadrons.However the landscape is very different for
weak transitions; the connection of U- \& V-spin symmetries are important. We
have to understand the differences between Penguin {\em operators} vs. Penguin
{\em diagrams}. (d) Collaborations of experimenters \& theorists are crucial
with {\em judgment}. There is a `hot' news from the conference ICHEP2016: LHCb
data show evidence of {\bf CP} asymmetries in the {\bf T}-odd moment from
$\Lambda_b^0 \to p \pi^-\pi^+\pi^-$. LHCb will follow this `road' with
$\Lambda_b^0 \to p \pi^-K^+K^-$, $\Lambda_b^0 \to p K^- \pi^+\pi^-$ \&
$\Lambda_b^0 \to p K^-K^+K^-$ in run-1. With much more data it is crucial to
probe its features in {\em regional} asymmetries. \\ A quote from Marinus, who
was a $\sim$ 468 AD student of Proklos, a well-known Neoplatonic philosopher:
"Only {\em being} good is one thing -- but good {\em doing} it is the other
one!"


title: Concepts of polymer statistical topology

abstract:
  I review few conceptual steps in analytic description of topological
interactions, which constitute the basis of a new interdisciplinary branch in
mathematical physics, "Statistical Topology", emerged at the edge of topology
and statistical physics of fluctuating non-phantom rope-like objects. This new
branch is called statistical (or probabilistic) topology.


title: X-ray Pulsars

abstract:
  X-ray pulsars shine thanks to the conversion of the gravitational energy of
accreted material to X-ray radiation. The accretion rate is modulated by
geometrical and hydrodynamical effects in the stellar wind of the pulsar
companions and/or by instabilities in accretion discs. Wind driven flows are
highly unstable close to neutron stars and responsible for X-ray variability by
factors $10^3$ on time scale of hours. Disk driven flows feature slower state
transitions and quasi periodic oscillations related to orbital motion and
precession or resonance. On shorter time scales, and closer to the surface of
the neutron star, X-ray variability is dominated by the interactions of the
accreting flow with the spinning magnetosphere. When the pulsar magnetic field
is large, the flow is confined in a relatively narrow accretion column, whose
geometrical properties drive the observed X-ray emission. In low magnetized
systems, an increasing accretion rate allows the ignition of powerful explosive
thermonuclear burning at the neutron star surface. Transitions from rotation-
to accretion-powered activity has been observed in rare cases and proved the
link between these classes of pulsars.


title:
Trigonometric collocation methods based on Lagrange basis polynomials
  for multi-frequency oscillatory second-order differential equations

abstract:
  In the present work, a kind of trigonometric collocation methods based on
Lagrange basis polynomials is developed for effectively solving multi-frequency
oscillatory second-order differential equations
$q^{\prime\prime}(t)+Mq(t)=f\big(q(t)\big)$. The properties of the obtained
methods are investigated. It is shown that the convergent condition of these
methods is independent of $\norm{M}$, which is very crucial for solving
oscillatory systems. A fourth-order scheme of the methods is presented.
Numerical experiments are implemented to show the remarkable efficiency of the
methods proposed in this paper.


title:
Perturbative instability of inflationary cosmology from quantum
  potentials

abstract:
  It was argued that the Raychaudhuri equation with a quantum correction term
seems to avoid the Big Bang singularity and to characterize an everlasting
Universe [PLB741,276(2015)]. Critical comments on both conclusions and on the
correctness of the key expressions of this work were discussed in literature
[MPLA31(2016)1650044]. In the present work, we have analyzed the perturbative
(in)stability conditions in the inflationary era of the early Universe. We
conclude that both unstable and stable modes are incompatible with the
corresponding ones obtained in the standard FLRW Universe. We have shown that
unstable modes do exist at small (an)isotropic perturbation and for different
equations of state. Inequalities for both unstable and stable solutions with
the standard FLRW space were derived. They reveal that in the FLRW flat
Universe both perturbative instability and stability are likely. While negative
stability modes have been obtained for radiation- and matter-dominated eras,
merely, instability modes exist in case of a finite cosmological constant and
also if the vacuum energy dominates the cosmic background geometry.


title: Size-Ramsey numbers of cycles versus a path

abstract:
  The size-Ramsey number $\hat{R}(\mathcal{F},H)$ of a family of graphs
$\mathcal{F}$ and a graph $H$ is the smallest integer $m$ such that there
exists a graph $G$ on $m$ edges with the property that any colouring of the
edges of $G$ with two colours, say, red and blue, yields a red copy of a graph
from $\mathcal{F}$ or a blue copy of $H$. In this paper we first focus on
$\mathcal{F} = \mathcal{C}_{\le cn}$, where $\mathcal{C}_{\le cn}$ is the
family of cycles of length at most $cn$, and $H = P_n$. In particular, we show
that $2.00365 n \le \hat{R}(\mathcal{C}_{\le n},P_n) \le 31n$. Using similar
techniques, we also managed to analyze $\hat{R}(C_n,P_n)$, which was
investigated before but only using the regularity method.


title:
The Conversion of CESR to Operate as the Test Accelerator, CesrTA, Part
  4: Superconducting Wiggler Diagnostics

abstract:
  Cornell's electron/positron storage ring (CESR) was modified over a series of
accelerator shutdowns beginning in May 2008, which substantially improves its
capability for research and development for particle accelerators. CESR's
energy span from 1.8 to 5.6 GeV with both electrons and positrons makes it
appropriate for the study of a wide spectrum of accelerator physics issues and
instrumentation related to present light sources and future lepton damping
rings. Additionally a number of these are also relevant for the beam physics of
proton accelerators. This paper, the last in a series of four, describes the
vacuum system modifications of the superconducting wigglers to accommodate the
diagnostic instrumentation for the study of electron cloud (EC) behavior within
wigglers. Earlier papers provided an overview of the accelerator physics
program, the general modifications of CESR, the modifications of the vacuum
system necessary for the conversion of CESR to the test accelerator, CesrTA,
enhanced to study such subjects as low emittance tuning methods, EC effects,
intra-beam scattering, fast ion instabilities as well as general improvements
to beam instrumentation. While the initial studies of CesrTA focussed on
questions related to the International Linear Collider damping ring design,
CESR is a very versatile storage ring, capable of studying a wide range of
accelerator physics and instrumentation questions.


title: Heavy Exotic Molecules with Charm and Bottom

abstract:
  We revisit the formation of pion-mediated heavy-light exotic molecules with
both charm and bottom and their chiral partners under the general strictures of
both heavy-quark and chiral symmetry. The chiral exotic partners with good
parity formed using the $(0^+, 1^+)$ multiplet are about twice more bound than
their primary exotic partners formed using the $(0^-,1^-)$ multiplet. The
chiral couplings across the multiplets $(0^\pm, 1^\pm)$ cause the chiral exotic
partners to unbind, and the primary exotic molecules to be about twice more
bound, for $J\leq 1$. Our multi-channel coupling results show that only the
charm isosinglet exotic molecules with $J^{PC}=1^{++}$ binds, which we identify
as the reported neutral $X(3872)$. Also, the bottom isotriplet exotic with
$J^{PC}=1^{+-}$ binds, which we identify as a mixture of the reported charged
exotics $Z^+_b(10610)$ and $Z^+_b(10650)$. The bound isosinglet with
$J^{PC}=1^{++}$ is suggested as a possible neutral $X_b(10532)$ not yet
reported.


title:
Tails assumptions and posterior concentration rates for mixtures of
  Gaussians

abstract:
  Nowadays in density estimation, posterior rates of convergence for location
and location-scale mixtures of Gaussians are only known under light-tail
assumptions; with better rates achieved by location mixtures. It is
conjectured, but not proved, that the situation should be reversed under heavy
tails assumptions. The conjecture is based on the feeling that there is no need
to achieve a good order of approximation in regions with few data (say, in the
tails), favoring location-scale mixtures which allow for spatially varying
order of approximation. Here we test the previous argument on the Gaussian
errors mean regression model with random design, for which the light tail
assumption is not required for proofs. Although we cannot invalidate the
conjecture due to the lack of lower bound, we find that even with heavy tails
assumptions, location-scale mixtures apparently perform always worst than
location mixtures. However, the proofs suggest to introduce hybrid
location-scale mixtures that are find to outperform both location and
location-scale mixtures, whatever the nature of the tails. Finally, we show
that all tails assumptions can be released at the price of making the prior
distribution covariate dependent.


title: Hadro-quarkonium from Lattice QCD

abstract:
  The hadro-quarkonium picture [S. Dubinskiy and M.B. Voloshin, Phys. Lett. B
666, 344 (2008)] provides one possible interpretation for the pentaquark
candidates with hidden charm, recently reported by the LHCb Collaboration, as
well as for some of the charmonium-like "X,Y,Z" states. In this picture, a
heavy quarkonium core resides within a light hadron giving rise to four- or
five-quark/antiquark bound states. We test this scenario in the heavy quark
limit by investigating the modification of the potential between a static
quark-antiquark pair induced by the presence of a hadron. Our lattice QCD
simulations are performed on a Coordinated Lattice Simulations (CLS) ensemble
with $N_f = 2+1$ flavours of non-perturbatively improved Wilson quarks at a
pion mass of about 223 MeV and a lattice spacing of about 0.0854 fm. We study
the static potential in the presence of a variety of light mesons as well as of
octet and decuplet baryons. In all these cases, the resulting configurations
are favoured energetically. The associated binding energies between the
quarkonium in the heavy quark limit and the light hadron are found to be
smaller than a few MeV, similar in strength to deuterium binding. It needs to
be seen if the small attraction survives in the infinite volume limit and
supports bound states or resonances.


title:
Dressed photon-orbital states in a quantum dot: Inter-valley spin
  resonance

abstract:
  The valley degree of freedom is intrinsic to spin qubits in Si/SiGe quantum
dots. It has been viewed alternately as a hazard, especially when the lowest
valley-orbit splitting is small compared to the thermal energy, or as an asset,
most prominently in proposals to use the valley degree of freedom itself as a
qubit. Here we present experiments in which microwave electric field driving
induces transitions between both valley-orbit and spin states. We show that
this system is highly nonlinear and can be understood through the use of
dressed photon-orbital states, enabling a unified understanding of the six
microwave resonance lines we observe. Some of these resonances are inter-valley
spin transitions that arise from a non-adiabatic process in which both the
valley and the spin degree of freedom are excited simultaneously. For these
transitions, involving a change in valley-orbit state, we find a tenfold
increase in sensitivity to electric fields and electrical noise compared to
pure spin transitions, strongly reducing the phase coherence when changes in
valley-orbit index are incurred. In contrast to this non-adiabatic transition,
the pure spin transitions, whether arising from harmonic or subharmonic
generation, are shown to be adiabatic in the orbital sector. The non-linearity
of the system is most strikingly manifest in the observation of a dynamical
anti-crossing between a spin-flip, inter-valley transition and a three-photon
transition enabled by the strong nonlinearity we find in this seemly simple
system.


title: Classification of Affine Symmetry Groups of Orbit Polytopes

abstract:
  Let $G$ be a finite group acting linearly on a vector space $V$. We consider
the linear symmetry groups $\operatorname{GL}(Gv)$ of orbits $Gv\subseteq V$,
where the \emph{linear symmetry group} $\operatorname{GL}(S)$ of a subset
$S\subseteq V$ is defined as the set of all linear maps of the linear span of
$S$ which permute $S$. We assume that $V$ is the linear span of at least one
orbit $Gv$. We define a set of \emph{generic points} in $V$, which is
Zariski-open in $V$, and show that the groups $\operatorname{GL}(Gv)$ for $v$
generic are all isomorphic, and isomorphic to a subgroup of every symmetry
group $\operatorname{GL}(Gw)$ such that $V$ is the linear span of $Gw$. If the
underlying characteristic is zero, "isomorphic" can be replaced by "conjugate
in $\operatorname{GL}(V)$". Moreover, in the characteristic zero case, we show
how the character of $G$ on $V$ determines this generic symmetry group. We
apply our theory to classify all affine symmetry groups of vertex-transitive
polytopes, thereby answering a question of Babai (1977).


title:
An equation of state for purely kinetic k-essence inspired by cosmic
  topological defects

abstract:
  We investigate the physical properties of a purely kinetic k-essence model
with an equation of state motivated in superconducting membranes. We compute
the equation of state parameter $w$ and discuss its physical evolution via a
nonlinear equation of state. Using the adiabatic speed of sound and energy
density, we restrict the range of parameters of the model in order to have an
acceptable physical behavior. Furthermore, we analyze the evolution of the
luminosity distance $d_{L}$ with redshift $z$ by comparing (normalizing) it
with the $\Lambda$CDM model. Since the equation of state parameter is
$z$-dependent the evolution of the luminosity distance is also analyzed using
the Alcock-Paczy\'{n}ski test.


title: Estimation of a discrete probability under constraint of k-monotony

abstract:
  We propose two least-squares estimators of a discrete probability under the
constraint of k-monotony and study their statistical properties. We give a
characterization of these estimators based on the decomposition on a spline
basis of k-monotone sequences. We develop an algorithm derived from the Support
Reduction Algorithm and we finally present a simulation study to illustrate
their properties.


title:
Science Requirements and Trade-offs for the MOSAIC Instrument for the
  European ELT

abstract:
  Building on the comprehensive White Paper on the scientific case for
multi-object spectroscopy on the European ELT, we present the top-level
instrument requirements that are being used in the Phase A design study of the
MOSAIC concept. The assembled cases span the full range of E-ELT science and
generally require either 'high multiplex' or 'high definition' observations to
best exploit the excellent sensitivity and spatial performance of the
telescope. We highlight some of the science studies that are now being used in
trade-off studies to inform the capabilities of MOSAIC and its technical
design.


title: Generalized Brans-Dicke inflation with a quartic potential

abstract:
  Within the framework of Brans-Dicke gravity, we investigate inflation with
the quartic potential, $\lambda\varphi^4/4$, in the presence of generalized
Brans-Dicke parameter $\omega_{\rm GBD}(\varphi)$. We obtain the inflationary
observables containing the scalar spectral index, the tensor-to-scalar ratio,
the running of the scalar spectral index and the equilateral non-Gaussianity
parameter in terms of general form of the potential $U(\varphi)$ and
$\omega_{\rm GBD}(\varphi)$. For the quartic potential, our results show that
the predictions of the model are in well agreement with the Planck 2015 data
for the generalized Brans-Dicke parameters $\omega_{\rm
GBD}(\varphi)=\omega_0\varphi^{n}$ and $\omega_0e^{b\varphi}$. This is in
contrast with both the Einstein and standard Brans-Dicke gravity, in which the
result of quartic potential is disfavored by the Planck data.


title:
Studying Criticality and Excitations of One Dimensional Systems by Time
  Matrix Product States

abstract:
  (Please refer to arXiv:1810.08050, which has completely different aims but
contains all the main contents of this paper) In this work, we propose to
access the information of criticality and excitations of one-dimensional
quantum systems by a matrix product state (MPS) defined in the (imaginary) time
direction. This state, dubbed as time MPS (tMPS), is a boundary state of tensor
network (TN) that represents the ground-state simulation after Trotter-Suzuki
decomposition. We show that the tMPS exhibits the structure of the continuous
MPS originally proposed for the field theories. The information of excitations,
e.g., dynamic correlation length and energy gap, can be accurately calculated
from the tMPS. The non-universal renormalization of velocity of the excitations
is given by a ratio between the correlations of the ground state and the tMPS.
When the system is at the quantum critical point, the tMPS is found to show the
logarithmic scaling law, where the scaling coefficient gives the central charge
that characterizes the criticality of the theory. Our work also implies that
the spectra of the transfer matrices defined by the ground state and tMPS
provide information of the low-lying masses of the theory in the continuous
limit. This could help to understand the role of the finiteness of the bond
dimension as an infra red regulator. Furthermore, we show from the perspective
of methodology that, the tMPS emerges from a generalized TN ab-initio
optimization principle scheme, which unifies the infinite density matrix
renormalization group and the infinite time-evolving block decimation
algorithms.


title:
Network coding in undirected graphs is either very helpful or not
  helpful at all

abstract:
  While it is known that using network coding can significantly improve the
throughput of directed networks, it is a notorious open problem whether coding
yields any advantage over the multicommodity flow (MCF) rate in undirected
networks. It was conjectured by Li and Li (2004) that the answer is "no". In
this paper we show that even a small advantage over MCF can be amplified to
yield a near-maximum possible gap.
  We prove that any undirected network with $k$ source-sink pairs that exhibits
a $(1+\varepsilon)$ gap between its MCF rate and its network coding rate can be
used to construct a family of graphs $G'$ whose gap is $\log(|G'|)^c$ for some
constant $c < 1$. The resulting gap is close to the best currently known upper
bound, $\log(|G'|)$, which follows from the connection between MCF and sparsest
cuts.
  Our construction relies on a gap-amplifying graph tensor product that, given
two graphs $G_1,G_2$ with small gaps, creates another graph $G$ with a gap that
is equal to the product of the previous two, at the cost of increasing the size
of the graph. We iterate this process to obtain a gap of $\log(|G'|)^c$ from
any initial gap.


title: Interpretable Nonlinear Dynamic Modeling of Neural Trajectories

abstract:
  A central challenge in neuroscience is understanding how neural system
implements computation through its dynamics. We propose a nonlinear time series
model aimed at characterizing interpretable dynamics from neural trajectories.
Our model assumes low-dimensional continuous dynamics in a finite volume. It
incorporates a prior assumption about globally contractional dynamics to avoid
overly enthusiastic extrapolation outside of the support of observed
trajectories. We show that our model can recover qualitative features of the
phase portrait such as attractors, slow points, and bifurcations, while also
producing reliable long-term future predictions in a variety of dynamical
models and in real neural data.


title: Exploring extra dimensions with scalar waves

abstract:
  This paper provides a pedagogical introduction to the physics of extra
dimensions focussing on the ADD, Randall-Sundrum and DGP models. In each of
these models, the familiar particles and fields of the standard model are
assumed to be confined to a four dimensional space-time called the brane; the
brane is a slice through a higher dimensional space-time called the bulk. The
geometry of the ADD, Randall-Sundrum and DGP space-times is described and the
relation between Randall-Sundrum and Anti-de-Sitter space-time is explained.
The necessary differential geometry background is introduced in an appendix
that presumes no greater mathematical preparation than multivariable calculus.
The ordinary wave equation and the Klein-Gordon equation are briefly reviewed
followed by an analysis of the propagation of scalar waves in the bulk in all
three extra-dimensional models. We also calculate the scalar field produced by
a static point source located on the brane for all three models. For the ADD
and Randall-Sundrum models at large distances the field looks like that of a
point source in four space-time dimensions but at short distances it crosses
over to a form appropriate to the higher dimensional space-time. For the DGP
model the field has the higher dimensional form at long distances rather than
short. The scalar field results provide qualitative insights into the
corresponding behavior of gravitational fields. In particular the explanation
within the ADD and Randall-Sundrum model of the weakness of gravity compared to
other forces is discussed as are the implications of the two models for
colliders and other experiments.


title: Grand Challenges for Global Brain Sciences

abstract:
  The next grand challenges for society and science are in the brain sciences.
A collection of 60+ scientists from around the world, together with 10+
observers from national, private, and foundations, spent two days together
discussing the top challenges that we could solve as a global community in the
next decade. We eventually settled on three challenges, spanning anatomy,
physiology, and medicine. Addressing all three challenges requires novel
computational infrastructure. The group proposed the advent of The
International Brain Station (TIBS), to address these challenges, and launch
brain sciences to the next level of understanding.


title:
Using Semantic Similarity for Input Topic Identification in
  Crawling-based Web Application Testing

abstract:
  To automatically test web applications, crawling-based techniques are usually
adopted to mine the behavior models, explore the state spaces or detect the
violated invariants of the applications. However, in existing crawlers, rules
for identifying the topics of input text fields, such as login ids, passwords,
emails, dates and phone numbers, have to be manually configured. Moreover, the
rules for one application are very often not suitable for another. In addition,
when several rules conflict and match an input text field to more than one
topics, it can be difficult to determine which rule suggests a better match.
This paper presents a natural-language approach to automatically identify the
topics of encountered input fields during crawling by semantically comparing
their similarities with the input fields in labeled corpus. In our evaluation
with 100 real-world forms, the proposed approach demonstrated comparable
performance to the rule-based one. Our experiments also show that the accuracy
of the rule-based approach can be improved by up to 19% when integrated with
our approach.


title: Representing convex geometries by almost-circles

abstract:
  Finite convex geometries are combinatorial structures. It follows from a
recent result of M.\ Richter and L.G.\ Rogers that there is an infinite set
$T_{rr}$ of planar convex polygons such that $T_{rr}$ with respect to geometric
convex hulls is a locally convex geometry and every finite convex geometry can
be represented by restricting the structure of $T_{rr}$ to a finite subset in a
natural way. An \emph{almost-circle of accuracy} $1-\epsilon$ is a
differentiable convex simple closed curve $S$ in the plane having an inscribed
circle of radius $r_1>0$ and a circumscribed circle of radius $r_2$ such that
the ratio $r_1/r_2$ is at least $1-\epsilon$. % Motivated by Richter and
Rogers' result, we construct a set $T_{new}$ such that (1) $T_{new}$ contains
all points of the plane as degenerate singleton circles and all of its
non-singleton members are differentiable convex simple closed planar curves;
(2) $T_{new}$ with respect to the geometric convex hull operator is a locally
convex geometry; (3) as opposed to $T_{rr}$, $T_{new}$ is closed with respect
to non-degenerate affine transformations; and (4) for every (small) positive
$\epsilon\in\real $ and for every finite convex geometry, there are continuum
many pairwise affine-disjoint finite subsets $E$ of $T_{new}$ such that each
$E$ consists of almost-circles of accuracy $1-\epsilon$ and the convex geometry
in question is represented by restricting the convex hull operator to $E$. The
affine-disjointness of $E_1$ and $E_2$ means that, in addition to $E_1\cap
E_2=\emptyset$, even $\psi(E_1)$ is disjoint from $E_2$ for every
non-degenerate affine transformation $\psi$.


title:
Elastic scattering of vortex electrons provides direct access to the
  Coulomb phase

abstract:
  Vortex electron beams are freely propagating electron waves carrying
adjustable orbital angular momentum with respect to the propagation direction.
Such beams were experimentally realized just a few years ago and are now used
to probe various electromagnetic processes. So far, these experiments used the
single vortex electron beams, either propagating in external fields or
impacting a target. Here, we investigate the elastic scattering of two such
aligned vortex electron beams and demonstrate that this process allows one to
experimentally measure features which are impossible to detect in the usual
plane-wave scattering. The scattering amplitude of this process is well
approximated by two plane-wave scattering amplitudes with different momentum
transfers, which interfere and give direct experimental access to the Coulomb
phase. This phase (shift) affects the scattering of all charged particles and
has thus received significant theoretical attention but was never probed
experimentally. We show that a properly defined azimuthal asymmetry, which has
no counterpart in plane-wave scattering, allows one to directly measure the
Coulomb phase as function of the scattering angle.


title: What did the 2016 Brexit referendum data really say?

abstract:
  The Brexit referendum took place in the UK in June, 2016. The unweighted
percentage of leavers over the whole population was 51.9%. In this paper,
first, we demonstrate that a 52%-48% split represents only a difference that is
not sufficiently different from a 50-50 split to claim a majority for either
side. Second, and most important, on this basis of the unweighted percentage,
statement like: The country voted to leave the EU, were made. When a statement
about a population is made based on a subset of it (the turnout rate for Brexit
was only 72% and therefore 37% of the eligible population voted Leave), it
comes with an element of uncertainty that should not be ignored. The unweighted
average disregards, not only between-region heterogeneity but also
within-region variability. Our analysis, controlling for both, finds that the
split of the Brexit is of negligible material significance and do not indicate
majority for either side.


title:
Dynamics of expansion of the Universe in the models with non-minimally
  coupled dark energy

abstract:
  We consider the dark energy model with barotropic equation of state, which
interacts with dark matter through gravitation and another force, causing the
energy-momentum exchange between them. Both components are described in
approximation of ideal fluids, which are parametrized by density and equation
of state parameters. Three types of interactions between dark components are
considered: the interaction independent from their densities, the one
proportional to density of dark energy and the one proportional to density of
dark matter. The equations which describe the expansion dynamics of homogeneous
and isotropic Universe and evolution of densities of both components for
different values of interaction parameter are obtained on the bases of the
general covariant conservation equations and Einstein's ones. For three kinds
of interactions we show the existence of the range of values of parameters of
dark energy for which the densities of dark components and their sum are
negative. We find the conditions of positivity of density of dark energy and
dark matter. The constraints on the value of parameter of interaction are
derived. The dynamics of expansion of the Universe with these interactions of
dark energy and dark matter is analysed.


title:
Parabolic Kazhdan-Lusztig basis, Schubert classes, and equivariant
  oriented cohomology

abstract:
  We study the equivariant oriented cohomology ring $h_T(G/P)$ of partial flag
varieties using the moment map approach. We define the right Hecke action on
this cohomology ring, and then prove that the respective Bott-Samelson classes
in $h_{T}(G/P)$ can be obtained by applying this action to the fundamental
class of the identity point, hence generalizing previously known results by
Brion, Knutson, Peterson, Tymoczko and others.
  We then focus on the equivariant oriented cohomology theory corresponding to
the 2-parameter Todd genus. We give a new interpretation of Deodhar's
construction of the parabolic Kazhdan-Lusztig basis. Based on it, we define the
parabolic Kazhdan-Lusztig (KL) Schubert classes independently of a reduced
word. We make a positivity conjecture, and a conjecture about the relationship
of such classes with smoothness of Schubert varieties. We then prove several
special cases.


title:
Globally hyperbolic moment model of arbitrary order for one-dimensional
  special relativistic Boltzmann equation

abstract:
  This paper extends the model reduction method by the operator projection to
the one-dimensional special relativistic Boltzmann equation. The derivation of
arbitrary order globally hyperbolic moment system is built on our careful study
of two families of the complicate Grad type orthogonal polynomials depending on
a parameter. We derive their recurrence relations, calculate their derivatives
with respect to the independent variable and parameter respectively, and study
their zeros and coefficient matrices in the recurrence formulas. Some
properties of the moment system are also proved. They include the eigenvalues
and their bound as well as eigenvectors,hyperbolicity, characteristic fields,
linear stability, and Lorentz covariance. A semi-implicit numerical scheme is
presented to solve a Cauchy problem of our hyperbolic moment system in order to
verify the convergence behavior of the moment method. The results show that the
solutions of our hyperbolic moment system can converge to the solution of the
special relativistic Boltzmann equation as the order of the hyperbolic moment
system increases.


title:
Glauber dynamics of 2D Kac-Blume-Capel model and their stochastic PDE
  limits

abstract:
  We study the Glauber dynamics of a two dimensional Blume-Capel model (or
dilute Ising model) with Kac potential parametrized by $(\beta,\theta)$ - the
"inverse temperature" and the "chemical potential". We prove that the locally
averaged spin field rescales to the solution of the dynamical $\Phi^4$ equation
near a curve in the $(\beta,\theta)$ plane and to the solution of the dynamical
$\Phi^6$ equation near one point on this curve. Our proof relies on a discrete
implementation of Da Prato-Debussche method as in a result by Mourrat-Weber but
an additional coupling argument is needed to show convergence of the linearized
dynamics.


title: Neural Networks with Smooth Adaptive Activation Functions for Regression

abstract:
  In Neural Networks (NN), Adaptive Activation Functions (AAF) have parameters
that control the shapes of activation functions. These parameters are trained
along with other parameters in the NN. AAFs have improved performance of Neural
Networks (NN) in multiple classification tasks. In this paper, we propose and
apply AAFs on feedforward NNs for regression tasks. We argue that applying AAFs
in the regression (second-to-last) layer of a NN can significantly decrease the
bias of the regression NN. However, using existing AAFs may lead to
overfitting. To address this problem, we propose a Smooth Adaptive Activation
Function (SAAF) with piecewise polynomial form which can approximate any
continuous function to arbitrary degree of error. NNs with SAAFs can avoid
overfitting by simply regularizing the parameters. In particular, an NN with
SAAFs is Lipschitz continuous given a bounded magnitude of the NN parameters.
We prove an upper-bound for model complexity in terms of fat-shattering
dimension for any Lipschitz continuous regression model. Thus, regularizing the
parameters in NNs with SAAFs avoids overfitting. We empirically evaluated NNs
with SAAFs and achieved state-of-the-art results on multiple regression
datasets.


title: A Non-Local Conventional Approach for Noise Removal in 3D MRI

abstract:
  In this paper, a filtering approach for the 3D magnetic resonance imaging
(MRI) assuming a Rician model for noise is addressed. Our denoising method is
based on the Conventional Approach (CA) proposed to deal with the noise issue
in the squared domain of the acquired magnitude MRI, where the noise
distribution follows a Chi-square model rather than the Rician one. In the CA
filtering method, the local samples around each voxel is used to estimate the
unknown signal value. Intrinsically, such a method fails to achieve the best
results where the underlying signal values have different statistical
properties. On the contrary, our proposal takes advantage of the data
redundancy and self-similarity properties of real MR images to improve the
noise removal performance. In other words, in our approach, the statistical
momentums of the given 3D MR volume are first calculated to explore the similar
patches inside a defined search volume. Then, these patches are put together to
obtain the noise-free value for each voxel under processing. The experimental
results on the synthetic as well as the clinical MR data show our proposed
method outperforms the other compared denoising filters.