title:
Arbitrary power-conserving field transformations with passive lossless
  omega-type bianisotropic metasurfaces

abstract:
  We present a general theory for designing realistic omega-type bianisotropic
metasurfaces (O-BMSs), unlocking their full potential for molding
electromagnetic fields. These metasurfaces, characterized by electric surface
impedance, magnetic surface admittance, and magnetoelectric coupling
coefficient, were previously considered for wavefront manipulation. However,
previous reports mainly considered plane-wave excitations, and implementations
included cumbersome metallic features. In this work, we prove that any field
transformation which locally conserves real power can be implemented via
passive and lossless meta-atoms characterized by closed-form expressions; this
allows rigorous incorporation of arbitrary source and scattering
configurations. Subsequently, we show that O-BMS meta-atoms can be implemented
using an asymmetric stack of three impedance sheets, an appealing structure for
printed circuit board fabrication. Our formulation reveals that, as opposed to
Huygens' metasurfaces (HMSs), which exhibit negligible magnetoelectric
coupling, O-BMSs are not limited to controlling the phase of transmitted
fields, but can rather achieve high level of control over the amplitude and
phase of reflected fields. This is demonstrated by designing O-BMSs for
reflectionless wide-angle refraction, independent surface-wave guiding, and a
highly-directive low-profile antenna, verified with full-wave simulations. This
straightforward methodology facilitates development of O-BMS-based devices for
controlling the near and far fields of arbitrary sources in complex scattering
configurations.


title: Symmetric Complete Intersections

abstract:
  We consider complete intersection ideals in a polynomial ring over a field of
characteristic zero that are stable under the action of the symmetric group
permuting the variables. We determine the possible representation types for
these ideals, and describe formulas for the graded characters of the
corresponding quotient rings.


title:
Lab-based limits on the Carroll-Field-Jackiw Lorentz-violating
  electrodynamics

abstract:
  The CPT-odd and Lorentz-violating Carroll-Field-Jackiw modification of
electrodynamics is discussed and we study its effects on the energy spectrum of
hydrogen, as well as in the generation of a momentum-dependent electric dipole
moment for charged leptons. We also briefly comment on the possibility of the
detection of Lorentz violation in measurements of vacuum birefringence in
resonant cavities. The bounds found are based on local laboratory experimental
limits and are not competitive with the ones coming from astrophysical
considerations.


title:
PM J03338+3320: Long-Period Superhumps in Growing Phase Following a
  Separate Precursor Outburst

abstract:
  We observed the first-ever recorded outburst of PM J03338+3320, the
cataclysmic variable selected by proper-motion survey. The outburst was
composed of a precursor and the main superoutburst. The precursor outburst
occurred at least 5 d before the maximum of the main superoutburst. Despite
this separation, long-period superhumps were continuously seen between the
precursor and main superoutburst. The period of these superhumps is longer than
the orbital period by 6.0(1)% and can be interpreted to reflect the dynamical
precession rate at the 3:1 resonance for a mass ratio of 0.172(4). These
superhumps smoothly evolved into those in the main superoutburst. These
observations provide the clearest evidence that the 3:1 resonance is triggered
by the precursor outburst, even if it is well separated, and the resonance
eventually causes the main superoutburst as predicted by the thermal-tidal
instability model. The presence of superhumps well before the superoutburst
cannot be explained by alternative models (the enhanced mass-transfer model and
the pure thermal instability model) and the present observations give a clear
support to the thermal-tidal instability model.


title: A Limit Theorem for Stochastically Decaying Partitions at the Edge

abstract:
  In this paper, we study the asymptotic behavior of the first, second, and so
on rows of stochastically decaying partitions. We establish that, with
appropriate scaling in time and length, the sequence of rows converges to the
Airy$_2$ line ensemble.
  This result was first established, in a more general setting, by Borodin and
Olshanski, who relied on the determinantal structure of the Poissonized
correlation functions. Our argument is based on a different, combinatorial
approach, developed by Okounkov. This approach may be useful in other problems
in which no determinantal structure is available, and also highlights the
similarity between random partitions and random matrices.


title:
Distinguishing between Personal Preferences and Social Influence in
  Online Activity Feeds

abstract:
  Many online social networks thrive on automatic sharing of friends'
activities to a user through activity feeds, which may influence the user's
next actions. However, identifying such social influence is tricky because
these activities are simultaneously impacted by influence and homophily. We
propose a statistical procedure that uses commonly available network and
observational data about people's actions to estimate the extent of
copy-influence---mimicking others' actions that appear in a feed. We assume
that non-friends don't influence users; thus, comparing how a user's activity
correlates with friends versus non-friends who have similar preferences can
help tease out the effect of copy-influence.
  Experiments on datasets from multiple social networks show that estimates
that don't account for homophily overestimate copy-influence by varying, often
large amounts. Further, copy-influence estimates fall below 1% of total actions
in all networks: most people, and almost all actions, are not affected by the
feed. Our results question common perceptions around the extent of
copy-influence in online social networks and suggest improvements to diffusion
and recommendation models.


title: Crouching AGM, Hidden Modularity

abstract:
  Special arithmetic series $f(x)=\sum_{n=0}^{\infty}c_nx^n$, whose
coefficients $c_n$ are normally given as certain binomial sums, satisfy
"self-replicating" functional identities. For example, the equation
$$\frac1{(1+4z)^2}f\biggl(\frac{z}{(1+4z)^3}\biggr)=\frac1{(1+2z)^2}f\biggl(\frac{z^2}{(1+2z)^3}\biggr)$$
generates a modular form $f(x)$ of weight 2 and level 7, when a related modular
parametrization $x=x(\tau)$ is properly chosen. In this note we investigate the
potential of describing modular forms by such self-replicating equations as
well as applications of the equations that do not make use of the modularity.
In particular, we outline a new recipe of generating AGM-type algorithms for
computing $\pi$ and other related constants. Finally, we indicate some
possibilities to extend the functional equations to a two-variable setting.


title:
Finiteness of polygonal relative equilibria for generalised
  quasi-homogeneous $n$-body problems and $n$-body problems in spaces of
  constant curvature

abstract:
  We prove for generalisations of quasi-homogeneous $n$-body problems with
center of mass zero and $n$-body problems in spaces of negative constant
Gaussian curvature that if the masses and rotation are fixed, there exists, for
every order of the masses, at most one equivalence class of relative equilibria
for which the point masses lie on a circle, as well as that there exists, for
every order of the masses, at most one equivalence class of relative equilibria
for which all but one of the point masses lie on a circle and rotate around the
remaining point mass. The method of proof is a generalised version of a proof
by J.M. Cors, G.R. Hall and G.E. Roberts on the uniqueness of co-circular
central configurations for power-law potentials.


title: Effective diffusion coefficient including the Marangoni effect

abstract:
  Surface-active molecules supplied from a particle fixed at the water surface
create a spatial gradient of the molecule concentration, resulting in Marangoni
convection. Convective flow transports the molecules far from the particle,
enhancing diffusion. We analytically derive the effective diffusion coefficient
associated with the Marangoni convection rolls. The resulting estimated
effective diffusion coefficient is consistent with our numerical results and
the apparent diffusion coefficient measured in experiments.


title: Counting Grid Aggregation for Event Retrieval and Recognition

abstract:
  Event retrieval and recognition in a large corpus of videos necessitates a
holistic fixed-size visual representation at the video clip level that is
comprehensive, compact, and yet discriminative. It shall comprehensively
aggregate information across relevant video frames, while suppress redundant
information, leading to a compact representation that can effectively
differentiate among different visual events. In search for such a
representation, we propose to build a spatially consistent counting grid model
to aggregate together deep features extracted from different video frames. The
spatial consistency of the counting grid model is achieved by introducing a
prior model estimated from a large corpus of video data. The counting grid
model produces an intermediate tensor representation for each video, which
automatically identifies and removes the feature redundancy across the
different frames. The tensor representation is subsequently reduced to a
fixed-size vector representation by averaging over the counting grid. When
compared to existing methods on both event retrieval and event classification
benchmarks, we achieve significantly better accuracy with much more compact
representation.


title:
Fluctuations of particle systems determined by Schur generating
  functions

abstract:
  We develop a new toolbox for the analysis of the global behavior of
stochastic discrete particle systems. We introduce and study the notion of the
Schur generating function of a random discrete configuration. Our main result
provides a Central Limit Theorem (CLT) for such a configuration given certain
conditions on the Schur generating function. As applications of this approach,
we prove CLT's for several probabilistic models coming from asymptotic
representation theory and statistical physics, including random lozenge and
domino tilings, non-intersecting random walks, decompositions of tensor
products of representations of unitary groups.


title:
Phase diagram and quantum-criticality of the two dimensional dissipative
  quantum XY model

abstract:
  The two-dimensional dissipative quantum XY model is applicable to the
quantum-critical properties of diverse experimental systems, ranging from the
superconductor to insulator transitions, ferromagnetic and antiferromagnetic
transitions in metals, to the loop-current order transition in the cuprates. We
solve the re-expression of this model in terms of topological excitations:
vortices and a variety of instantons, by renormalization group methods. The
calculations explain the extraordinary properties of the model discovered in
Monte-Carlo calculations: the separability of the quantum critical fluctuations
(QCF) in space and time, the spatial correlation length proportional to
logarithm of the temporal correlation length near the transition from
disordered to the fully ordered state, and the occurrence of a phase with
spatial order without temporal order. They are intimately related to the flow
of the metric of time in relation to the metric of space, i.e. of the dynamical
critical exponent $z$. These properties appear to be essential in understanding
the strange metallic phase found in a variety of quantum-critical transitions
as well as the accompanying high temperature superconductivity.


title:
Multiparty quantum key agreement protocol secure against collusion
  attacks

abstract:
  The fairness of a secure multi-party quantum key agreement (MQKA) protocol
requires that all involved parties are entirely peer entities and can equally
influence the outcome of the protocol to establish a shared key wherein no one
can decide the shared key alone. However, it is found that parts of the
existing MQKA protocols are sensitive to collusion attacks, i.e., some of the
dishonest participants can collaborate to predetermine the final key without
being detected. In this paper, a multi-party QKA protocol resisting collusion
attacks is proposed. Different from previous QKA protocol resisting $N-1$
coconspirators or resisting $1$ coconspirators, we investigate the general
circle-type MQKA protocol which can be secure against $t$ dishonest
participants' cooperation. Here, $t < N$. We hope the results of the presented
paper will be helpful for further research on fair MQKA protocols.


title: Layered Uplink Transmission in Clustered Cellular Networks

abstract:
  The demand for higher data rates and the scarce spectrum resources drive the
adoption of collaborative communication techniques. In this work we shown that
the existing cluster based collaborative schemes can be greatly improved in
terms of both the achievable performance, and complexity, by allowing
overlapping across clusters. Further improvement is achieved by incorporating
scheduling to the decoding process. Different variants of the improved schemes
are considered and are shown to achieve near optimum performance for practical
signal-to-noise ratios for the one- and two-dimensional (hexagonal) Wyner-type
models.


title:
Composition induced metal-insulator quantum phase transition in the
  Heusler type Fe2VAl

abstract:
  We report the magnetism and transport properties of the Heusler compound
Fe2+xV1-xAl at -0.10 < x < 0.10 under pressure and a magnetic field. A
metal-insulator quantum phase transition occurred at x = -0.05. Application of
pressure or a magnetic field facilitated the emergence of finite
zero-temperature conductivity around the critical point, which scaled
approximately according to the power law. At x < -0.05, a localized
paramagnetic spin appeared, whereas above the ferromagnetic quantum critical
point at x = 0.05, itinerant ferromagnetism was established. At the quantum
critical points at x = -0.05 and 0.05, the resistivity and specific heat
exhibited singularities characteristic of a Griffiths phase appearing as an
inhomogeneous electronic state.


title: Minimum Energy Problem on the Hypersphere

abstract:
  We consider the minimum energy problem on the unit sphere $\mathbb S^{d-1}$
in the Euclidean space $\mathbb R^d$, $d\geq 3$, in the presence of an external
field $Q$, where the charges are assumed to interact according to Newtonian
potential $1/r^{d-2}$, with $r$ denoting the Euclidean distance. We solve the
problem by finding the support of the extremal measure, and obtaining an
explicit expression for the density of the extremal measure. We then apply our
results to an external field generated by a point charge of positive magnitude,
placed at the North Pole of the sphere, and to a quadratic external field.


title:
Maximizing the Weighted Number of Spanning Trees: Near-$t$-Optimal
  Graphs

abstract:
  Designing well-connected graphs is a fundamental problem that frequently
arises in various contexts across science and engineering. The weighted number
of spanning trees, as a connectivity measure, emerges in numerous problems and
plays a key role in, e.g., network reliability under random edge failure,
estimation over networks and D-optimal experimental designs. This paper tackles
the open problem of designing graphs with the maximum weighted number of
spanning trees under various constraints. We reveal several new structures,
such as the log-submodularity of the weighted number of spanning trees in
connected graphs. We then exploit these structures and design a pair of
efficient approximation algorithms with performance guarantees and
near-optimality certificates. Our results can be readily applied to a wide
verity of applications involving graph synthesis and graph sparsification
scenarios.


title:
Jet-like Correlations with Direct-Photon and Neutral-Pion Triggers at
  $\sqrt{s_{_{NN}}} = 200$ GeV

abstract:
  Azimuthal correlations of charged hadrons with direct-photon ($\gamma_{dir}$)
and neutral-pion ($\pi^{0}$) trigger particles are analyzed in central Au+Au
and minimum-bias $p+p$ collisions at $\sqrt{s_{_{NN}}} = 200$ GeV in the STAR
experiment. The charged-hadron per-trigger yields at mid-rapidity from central
Au+Au collisions are compared with $p+p$ collisions to quantify the suppression
in Au+Au collisions. The suppression of the away-side associated-particle
yields per $\gamma_{dir}$ trigger is independent of the transverse momentum of
the trigger particle ($p_{T}^{\mathrm{trig}}$), whereas the suppression is
smaller at low transverse momentum of the associated charged hadrons
($p_{T}^{\mathrm{assoc}}$). Within uncertainty, similar levels of suppression
are observed for $\gamma_{dir}$ and $\pi^{0}$ triggers as a function of $z_{T}$
($\equiv p_T^{\mathrm{assoc}}/p_T^{\mathrm{trig}}$). The results are compared
with energy-loss-inspired theoretical model predictions. Our studies support
previous conclusions that the lost energy reappears predominantly at low
transverse momentum, regardless of the trigger energy.


title: Deformations of Fell bundles and twisted graph algebras

abstract:
  We consider Fell bundles over discrete groups, and the C*-algebra which is
universal for representations of the bundle. We define deformations of Fell
bundles, which are new Fell bundles with the same underlying Banach bundle but
with the multiplication deformed by a two-cocycle on the group. Every graph
algebra can be viewed as the C*-algebra of a Fell bundle, and there are are
many cocycles of interest with which to deform them. We thus obtain many of the
twisted graph algebras of Kumjian, Pask and Sims. We demonstate the utility of
our approach to these twisted graph algebras by proving that the deformations
associated to different cocycles can be assembled as the fibres of a C*-bundle.


title: Group Structures on Families of Subsets of a Group

abstract:
  A binary operation on any set induces a binary operation on its subsets. We
explore families of subsets of a group that become a group under the induced
operation and refer to such families as power groups of the given group. Our
results serve to characterize some types of groups in terms of their power
groups. In particular, we consider when the only power groups of a group are
the factor groups of its subgroups and when that is the case up to isomorphism.
We prove that the former are precisely those groups for which every element has
finite order and provide examples to illustrate that the latter is not always
the case. In the process we consider several natural questions such as whether
the identity element of the group must belong to the identity element of a
power group or the inverse of an element in a power group must consist of the
inverses of its elements.


title:
Unbiased Monte Carlo estimation for the expected value of partial
  perfect information

abstract:
  The expected value of partial perfect information (EVPPI) denotes the value
of eliminating uncertainty on a subset of unknown parameters involved in a
decision model. The EVPPI can be regarded as a decision-theoretic sensitivity
index, and has been widely used for identifying relatively important unknown
parameters. It follows from Jensen's inequality, however, that the standard
nested Monte Carlo computation of the EVPPI results in biased estimates. In
this paper we introduce two unbiased Monte Carlo estimators for the EVPPI based
on multilevel Monte Carlo method, introduced by Heinrich (1998) and Giles
(2008), and its extension by Rhee and Glynn (2012, 2015). Our unbiased
estimators are simple and straightforward to implement, and thus are of highly
practical use. Numerical experiments show that even the convergence behaviors
of our unbiased estimators are superior to that of the standard nested Monte
Carlo estimator.


title: An apparent paradox concerning the field of an ideal dipole

abstract:
  The electric or magnetic field of an ideal dipole is known to have a Dirac
delta function at the origin. The usual textbook derivation of this delta
function is rather ad hoc and cannot be used to calculate the delta-function
structure for higher multipole moments. Moreover, a naive application of
Gauss's law to the ideal dipole field appears to give an incorrect expression
for the dipole's effective charge density. We derive a general result for the
delta-function structure at the origin of an arbitrary ideal multipole field
without using any advanced techniques from distribution theory. We find that
the divergence of a singular vector field can contain a $\textit{derivative}$
of a Dirac delta function even if the field itself does not contain a delta
function. We also argue that a physical interpretation of the delta function in
the dipole field previously given in the literature is incorrect.


title:
Shocked POststarburst Galaxy Survey II: The Molecular Gas Content and
  Properties of a Subset of SPOGs

abstract:
  We present CO(1-0) observations of objects within the Shocked POststarburst
Galaxy Survey taken with the Institut de Radioastronomie Millimetrique (IRAM)
30m single dish and the Combined Array for Research for Millimeter Astronomy
(CARMA) interferometer. Shocked Poststarburst Galaxies (SPOGs) represent a
transitioning population of galaxies, with deep Balmer absorption (Hdelta>5A),
consistent with an intermediate-age (A-star) stellar population, and ionized
gas line ratios inconsistent with pure star formation. The CO(1-0) subsample
was selected from SPOGs detected by the Wide-field Infrared Survey Explorer
with 22um flux detected at a signal-to-noise (S/N)>3. Of the 52 objects
observed in CO(1-0), 47 are detected with S/N>3. A large fraction (37-46%) of
our CO-SPOG sample were visually classified as morphologically disrupted. The
H2 masses detected were between 10^(8.7-10.8) Msuns, consistent with the gas
masses found in normal galaxies, though approximately an order of magnitude
larger than the range seen in poststarburst galaxies. When comparing the 22um
and CO(1-0) fluxes, SPOGs diverge from the normal star-forming relation, having
22um fluxes in excess by a factor of <EMIR,SPOG>=4.91+0.42-0.39. The Na I D
characteristics of CO-SPOGs show that it is likely that many of these objects
host interstellar winds. Objects with the large Na I D enhancements also tend
to emit in the radio, suggesting possible AGN-driving of neutral winds.


title:
Experimental verification of the rotational sense and type of chiral
  spin spiral structure by spin-polarized scanning tunneling microscopy

abstract:
  We report on experimental verification of the rotational sense and type of
homogeneous chiral spin spiral order in a Mn monolayer on a W(110) substrate
using spin-polarized scanning tunneling microscopy. We found that the magnetic
contrast due to the spin spiral order almost vanishes with a magnetic tip
magnetized normal to the (001) plane, indicating that the spin spiral rotates
in the plane. From a shift in the most-contrasted sites by changing the tip
magnetization direction within the rotating plane, we reveal that the
rotational sense is left-handed, consistent with the previous results predicted
by first-principle calculations. By comparing the current system with a chiral
magnetic domain wall in Fe double layers on the same substrate, we found that
the polarity of the Dzyaloshinskii--Moriya interaction, the driving force of
those chiral magnets, is dominantly determined by the choice of the substrate
rather than the overlayer.


title: Derivations of quantizations in characteristic p

abstract:
  Let k be an algebraically closed field of odd characteristic. We describe
derivations of a large class of quantizations of affine normal Poisson
varieties over k.


title: Measuring burstiness for finite event sequences

abstract:
  Characterizing inhomogeneous temporal patterns in natural and social
phenomena is important to understand underlying mechanisms behind such complex
systems, hence even to predict and control them. Temporal inhomogeneities in
event sequences have been described in terms of bursts that are rapidly
occurring events in short time periods alternating with long inactive periods.
The bursts can be quantified by a simple measure, called burstiness parameter,
which was introduced by Goh and Barab\'asi [EPL \textbf{81}, 48002 (2008)]. The
burstiness parameter has been widely used due to its simplicity, which however
turns out to be strongly affected by the finite number of events in the time
series. As the finite-size effects on burstiness parameter have been largely
ignored, we analytically investigate the finite-size effects of the burstiness
parameter. Then we suggest an alternative definition of burstiness that is free
from finite-size effects and yet simple. Using our alternative burstiness
measure, one can distinguish the finite-size effects from the intrinsic bursty
properties in the time series. We also demonstrate the advantages of our
burstiness measure by analyzing empirical datasets.


title: Fe K$\alpha$ Profiles from Simulations of Accreting Black Holes

abstract:
  We present first results from a new technique for the prediction of Fe
K$\alpha$ profiles directly from general relativistic magnetohydrodynamic
(GRMHD) simulations. Data from a GRMHD simulation are processed by a Monte
Carlo global radiation transport code, which determines the X-ray flux
irradiating the disk surface and the coronal electron temperature
self-consistently. With that irradiating flux and the disk's density structure
drawn from the simulation, we determine the reprocessed Fe K$\alpha$ emission
from photoionization equilibrium and solution of the radiation transfer
equation. We produce maps of the surface brightness of Fe K$\alpha$ emission
over the disk surface, which---for our example of a $10 M_\odot$, Schwarzschild
black hole accreting at $1\%$ the Eddington value---rises steeply one
gravitational radius outside the radius of the innermost stable circular orbit
and then falls $\propto r^{-2}$ at larger radii. We explain these features of
the Fe K$\alpha$ radial surface brightness profile as consequences of the
disk's ionization structure and an extended coronal geometry, respectively. We
also present the corresponding Fe K$\alpha$ line profiles as would be seen by
distant observers at several inclinations. Both the shapes of the line profiles
and the equivalent widths of our predicted K$\alpha$ lines are qualitatively
similar to those typically observed from accreting black holes. Most
importantly, this work represents a direct link between theory and observation:
in a fully self-consistent way, we produce observable results---iron
fluorescence line profiles---from the theory of black hole accretion with
almost no phenomenological assumptions.


title: A Visible QCD Axion from an Enlarged Color Group

abstract:
  We consider the possibility of an enlarged QCD color group, SU(3+$N^\prime$)
spontaneously broken to SU(3)$_c\times$SU($N^\prime$) with extra vector-like
quarks transforming in the fundamental representation. When the heavy quarks
are integrated out below the PQ-breaking scale, they generate an axion coupling
which simultaneously solves the strong CP problem for both gauge groups.
However, the axion mass now receives a new nonperturbative contribution from
the SU($N^\prime$) confinement scale, which can be substantially larger than
the QCD scale. This can increase the axion mass to be at or above the
electroweak scale. This visible axion can then decay into gluons and photons
giving rise to observable signals at Run-II of the LHC. In particular, if the
mass is identified with the 750 GeV diphoton resonance then the new confinement
scale is $\sim$ TeV and the PQ-breaking scale is $\sim$ 10 TeV. This predicts
vector-like quarks and a PQ scalar resonance in the multi-TeV range, with the
possibility that dark matter is an SU($N^\prime$) baryon.


title:
Asymptotic stability of a Korteweg-de Vries equation with a
  two-dimensional center manifold

abstract:
  Local asymptotic stability analysis is conducted for an
initial-boundary-value problem of a Korteweg-de Vries equation posed on a
finite interval $\left[0, 2\pi \sqrt{7/3}\right]$. The equation comes with a
Dirichlet boundary condition at the left end-point and both of the Dirichlet
and Neumann homogeneous boundary conditions at the right end-point. It is known
that the associated linearized equation around the origin is not asymptotically
stable. In this paper, the nonlinear Korteweg-de Vries equation is proved to be
locally asymptotically stable around the origin through the center manifold
method. In particular, the existence of a two-dimensional local center manifold
is presented, which is locally exponentially attractive. By analyzing the
Korteweg-de Vries equation restricted on the local center manifold, a
polynomial decay rate of the solution is obtained.


title: Quantum noise theory for phonon transport through nanostructures

abstract:
  We have developed a quantum noise approach to study the phonon transport
through nanostructures. The nanostructures acting as phonon channels are
attached to two phonon reservoirs. And the temperature drop between the two
reservoirs drives the phonon transport through the channels. We have derived a
quantum Langevin equation(QLE) to describe the phonon transport with the
quantum noise originated from the thermal fluctuation of the reservoirs. Within
the Markov approximation, the QLE is used to get the thermal conductivity
$\kappa$ of the nanostructures and the finite size effect of the $\kappa$ then
is studied. In this study, the advantage of the quantum noise approach lays on
the fact that no any local temperature needs to be defined for the
nanostructures in its non-equilibrium state.


title:
A Particle-Filtering Based Approach for Distributed Fault Diagnosis of
  Large-Scale Interconnected Nonlinear Systems

abstract:
  This paper deals with the problem of designing a distributed fault detection
and isolation algorithm for nonlinear large-scale systems that are subjected to
multiple fault modes. To solve this problem, a network of communicating
detection nodes is deployed to monitor the monolithic process. Each node
consists of an estimator with partial observation of the system's state. The
local estimator executes a distributed variation of the particle filtering
algorithm using the partial sensor measurements and the fault progression model
of the process. During the implementation of the algorithm, each node
communicates with its neighbors by sharing pre-processed information. The
communication topology is defined using graph theoretic tools. The information
fusion between the neighboring nodes is performed by means of a distributed
average consensus algorithm to ensure the agreement over the value of the local
likelihood functions. The proposed method enables online hypothesis testing
without the need of a bank of estimators. Numerical simulations demonstrate the
efficiency of the proposed approach.


title: Discovering items with potential popularity on social media

abstract:
  Predicting the future popularity of online content is highly important in
many applications. Preferential attachment phenomena is encountered in scale
free networks.Under it's influece popular items get more popular thereby
resulting in long tailed distribution problem. Consequently, new items which
can be popular (potential ones), are suppressed by the already popular items.
This paper proposes a novel model which is able to identify potential items. It
identifies the potentially popular items by considering the number of links or
ratings it has recieved in recent past along with it's popularity decay. For
obtaining an effecient model we consider only temporal features of the content,
avoiding the cost of extracting other features. We have found that people
follow recent behaviours of their peers. In presence of fit or quality items
already popular items lose it's popularity. Prediction accuracy is measured on
three industrial datasets namely Movielens, Netflix and Facebook wall post.
Experimental results show that compare to state-of-the-art model our model have
better prediction accuracy.


title: Stability of gravitating charged-scalar solitons in a cavity

abstract:
  We present new regular solutions of Einstein-charged scalar field theory in a
cavity. The system is enclosed inside a reflecting mirror-like boundary, on
which the scalar field vanishes. The mirror is placed at the zero of the scalar
field closest to the origin, and inside this boundary our solutions are
regular. We study the stability of these solitons under linear, spherically
symmetric perturbations of the metric, scalar and electromagnetic fields. If
the radius of the mirror is sufficiently large, we present numerical evidence
for the stability of the solitons. For small mirror radius, some of the
solitons are unstable. We discuss the physical interpretation of this
instability.


title:
Classical deformations of noncompact surfaces and their moduli of
  instantons

abstract:
  We describe semiuniversal deformation spaces for the noncompact surfaces $Z_k
:= \operatorname{Tot} (\mathcal O_{\mathbb P^1} (-k))$ and prove that any
nontrivial deformation $Z_k (\tau)$ of $Z_k$ is affine.
  It is known that the moduli spaces of instantons of charge $j$ on $Z_k$ are
quasi-projective varieties of dimension $2j-k-2$. In contrast, our results
imply that the moduli spaces of instantons on any nontrivial deformation $Z_k
(\tau)$ are empty.


title: Top-quark pole mass in the tadpole-free MS-bar scheme

abstract:
  The complex pole mass of the top quark is presented at full two-loop order in
the Standard Model, augmenting the known four-loop QCD contributions. The input
parameters are the MS-bar Yukawa and gauge couplings, the Higgs self-coupling,
and the Higgs vacuum expectation value (VEV). Here, the VEV is defined as the
minimum of the full effective potential in Landau gauge, so that tadpoles
vanish. This is an alternative to earlier results that instead minimize the
tree-level potential, resulting in a VEV that is gauge-fixing independent but
accompanied by negative powers of the Higgs self-coupling in perturbative
expansions. The effects of non-zero Goldstone boson mass are eliminated by
resummation. I also study the renormalization scale dependence of the
calculated pole mass.


title: Local property of maximal plurifinely plurisubharmonic functions

abstract:
  In this paper, we prove that a continuous $\mathcal F$-plurisubharmonic
functions defined in an $\mathcal F$-open set in $\mathbb C^n$ is $\mathcal
F$-maximal if and only if it is $\mathcal F$-locally $\mathcal F$-maximal.


title: Online VNF Scaling in Datacenters

abstract:
  Network Function Virtualization (NFV) is a promising technology that promises
to significantly reduce the operational costs of network services by deploying
virtualized network functions (VNFs) to commodity servers in place of dedicated
hardware middleboxes. The VNFs are typically running on virtual machine
instances in a cloud infrastructure, where the virtualization technology
enables dynamic provisioning of VNF instances, to process the fluctuating
traffic that needs to go through the network functions in a network service. In
this paper, we target dynamic provisioning of enterprise network services -
expressed as one or multiple service chains - in cloud datacenters, and design
efficient online algorithms without requiring any information on future traffic
rates. The key is to decide the number of instances of each VNF type to
provision at each time, taking into consideration the server resource
capacities and traffic rates between adjacent VNFs in a service chain. In the
case of a single service chain, we discover an elegant structure of the problem
and design an efficient randomized algorithm achieving a e/(e-1) competitive
ratio. For multiple concurrent service chains, an online heuristic algorithm is
proposed, which is O(1)-competitive. We demonstrate the effectiveness of our
algorithms using solid theoretical analysis and trace-driven simulations.


title:
Instability of sphaleron black holes in asymptotically anti-de Sitter
  space-time

abstract:
  We prove that sphaleron black holes in ${\mathfrak {su}}(2)$
Einstein-Yang-Mills-Higgs theory with a Higgs doublet in four-dimensional,
asymptotically anti-de Sitter space-time are unstable.


title:
Split-Step Method for Generalized Non-Linear Equations: A Three Operator
  Story

abstract:
  This paper describes an updated exponential Fourier based split-step method
that can be applied to a greater class of partial differential equations than
previous methods would allow. These equations arise in physics and engineering,
a notable example being the generalized derivative non-linear Schr\"odinger
equation that arises in non-linear optics with self-steepening terms. These
differential equations feature terms that were previously inaccessible to model
accurately with low computational resources. The new method maintains a 3rd
order error even with these additional terms and models the equation in all
three spatial dimensions and time. The class of non-linear differential
equations that this method applies to is shown. The method is fully derived and
implementation of the method in the split-step architecture is shown. This
paper lays the mathematical ground work for an upcoming paper employing this
method in white-light generation simulations in bulk material.


title: On the existence of harmonic mappings between doubly connected domains

abstract:
  While the existence of conformal mappings between doubly connected domains is
characterized by their conformal moduli, no such characterization is available
for harmonic diffeomorphisms. Intuitively, one expects their existence if the
domain is not too thick compared to the codomain. We make this intuition
precise by showing that for a Dini-smooth doubly connected domain $\Omega^*$
there exists $\epsilon>0$ such that for every doubly connected domain $\Omega$
with $\operatorname{Mod} \Omega^*<\operatorname{Mod}\Omega<\operatorname{Mod}
\Omega^*+\epsilon$ there exists a harmonic diffeomorphism from $\Omega$ onto
$\Omega^*$.


title:
Simulation of White Light Generation and Near Light Bullets Using a
  Novel Numerical Technique

abstract:
  An accurate and efficient simulation has been devised, employing a new
numerical technique to simulate the derivative generalised non-linear
Schr\"odinger equation in all three spatial dimensions and time. The simulation
models all pertinent effects such as self-steepening and plasma for the
non-linear propagation of ultrafast optical radiation in bulk material.
Simulation results are compared to published experimental spectral data of an
example ytterbium aluminum garnet system at 3.1um radiation and fits to within
a factor of 5. The simulation shows that there is a stability point near the
end of the 2 mm crystal where a quasi-light bullet (spatial temporal soliton)
is present. Within this region, the pulse is collimated at a reduced diameter
(factor of ~2) and there exists a near temporal soliton at the spatial center.
The temporal intensity within this stable region is compressed by a factor of
~4 compared to the input. This study shows that the simulation highlights new
physical phenomena based on the interplay of various linear, non-linear and
plasma effects that go beyond the experiment and is thus integral to achieving
accurate designs of white light generation systems for optical applications. An
adaptive error reduction algorithm tailor made for this simulation will also be
presented in appendix.


title: Small-Scale Conformity of the Virgo Cluster Galaxies

abstract:
  We investigate the small-scale conformity in color between bright galaxies
and their faint companions in the Virgo cluster. Cluster member galaxies are
spectroscopically determined using the Extended Virgo Cluster Catalog (EVCC)
and the Sloan Digital Sky Survey Data Release 12 (SDSS DR12). We find that the
luminosity-weighted mean color of faint galaxies depends on the color of
adjacent bright galaxy as well as on the cluster-scale environment
(gravitational potential index). From this result for the entire area of the
Virgo cluster, it is not distinguishable whether the small-scale conformity is
genuine or is artificially produced due to cluster-scale variation of galaxy
color. To disentangle this degeneracy, we divide the Virgo cluster area into
three sub-areas so that the cluster-scale environmental dependence is
minimized: A1 (central), A2 (intermediate) and A3 (outermost). We find
conformity in color between bright galaxies and their faint companions
(color-color slope significance S ~ 2.73 sigma and correlation coefficient cc ~
0.50) in A2, where the cluster-scale environmental dependence is almost
negligible. On the other hand, the conformity is not significant or very
marginal (S ~ 1.75 sigma and cc ~ 0.27) in A1. The conformity is not
significant either in A3 (S ~ 1.59 sigma and cc ~ 0.44), but the sample size is
too small in this area. These results are consistent with a scenario in which
the small-scale conformity in a cluster is a vestige of infallen groups and
these groups lose conformity as they come closer to the cluster center.


title: Nonzero-sum risk-sensitive stochastic differential games

abstract:
  We study two person nonzero-sum stochastic differential games with
risk-sensitive discounted and ergodic cost criteria. Under certain conditions
we establish a Nash equilibrium in Markov strategies for the discounted cost
criterion and a Nash equilibrium in stationary strategies for the ergodic cost
criterion. We achieve our results by studying the relevant systems of coupled
HJB equations.


title:
Consistent systems of correlators in non-semisimple conformal field
  theory

abstract:
  Based on the modular functor associated with a -- not necessarily semisimple
-- finite non-degenerate ribbon category $\mathcal D$, we present a definition
of a consistent system of bulk field correlators for a conformal field theory
which comprises invariance under mapping class group actions and compatibility
with the sewing of surfaces. We show that when restricting to surfaces of genus
zero such systems are in bijection with commutative symmetric Frobenius
algebras in $\mathcal D$, while for surfaces of any genus they are in bijection
with modular Frobenius algebras in $\mathcal D$. This provides additional
insight into structures familiar from rational conformal field theories and
extends them to rigid logarithmic conformal field theories.


title:
Stress-induced nematicity in EuFe2As2 studied by phononic Raman
  spectroscopy

abstract:
  We use polarized Raman scattering to study the structural phase transition in
EuFe2As2, the parent compound of the 122-ferropnictide superconductors. The
in-plane lattice anisotropy is characterized by measurements of the side
surface with different strains induced using different preparation methods. We
show that while a fine surface polishing leaves the samples free of residual
internal strain, in which case the onset of the C4 symmetry breaking is
observed at the nominal structural phase transition temperature Ts, cutting the
side surface induces a permanent four-fold rotational symmetry C4 breaking
spanning tens of degrees above Ts.


title:
Effects of low-lying excitations on ground-state energy and energy gap
  of Sherrington-Kirkpatrick model in transverse field

abstract:
  We present an extensive numerical study of the Sherrington-Kirkpatrick model
in transverse field. Recent numerical studies of quantum spin-glasses have
focused on exact diagonalization of the full Hamiltonian for small systems
($\approx$ 20 spins). However, such exact numerical treatments are difficult to
apply on larger systems. We propose making an approximation by using only a
subspace of the full Hilbert space spanned by low-lying excitations consisting
of one-spin flipped and two-spin flipped states. The approximation procedure is
carried out within the theoretical framework of Hartree-Fock approximation and
Configuration Interaction. Although not exact, our approach allows us to study
larger system sizes comparable to that achievable by state of the art Quantum
Monte Carlo simulations. We calculate two quantities of interest due to recent
advances in quantum annealing, the ground-state energy and the energy gap
between the ground and first excited state. For the energy gap, we derive a
novel formula that enables it to be calculated using just the ground-state
wavefunction, thereby circumventing the need to diagonalize the Hamiltonian. We
calculate the scalings of the energy gap and the leading correction to the
extensive part of the ground-state energy with system size, which are difficult
to obtain with current methods.


title:
Less is more: zero-shot learning from online textual documents with
  noise suppression

abstract:
  Classifying a visual concept merely from its associated online textual
source, such as a Wikipedia article, is an attractive research topic in
zero-shot learning because it alleviates the burden of manually collecting
semantic attributes. Several recent works have pursued this approach by
exploring various ways of connecting the visual and text domains. This paper
revisits this idea by stepping further to consider one important factor: the
textual representation is usually too noisy for the zero-shot learning
application. This consideration motivates us to design a simple-but-effective
zero-shot learning method capable of suppressing noise in the text.
  More specifically, we propose an $l_{2,1}$-norm based objective function
which can simultaneously suppress the noisy signal in the text and learn a
function to match the text document and visual features. We also develop an
optimization algorithm to efficiently solve the resulting problem. By
conducting experiments on two large datasets, we demonstrate that the proposed
method significantly outperforms the competing methods which rely on online
information sources but without explicit noise suppression. We further make an
in-depth analysis of the proposed method and provide insight as to what kind of
information in documents is useful for zero-shot learning.


title:
Extending Expected Improvement for High-dimensional Stochastic
  Optimization of Expensive Black-Box Functions

abstract:
  Design optimization under uncertainty is notoriously difficult when the
objective function is expensive to evaluate. State-of-the-art techniques, e.g,
stochastic optimization or sampling average approximation, fail to learn
exploitable patterns from collected data and require an excessive number of
objective function evaluations. There is a need for techniques that alleviate
the high cost of information acquisition and select sequential simulations
optimally. In the field of deterministic single-objective unconstrained global
optimization, the Bayesian global optimization (BGO) approach has been
relatively successful in addressing the information acquisition problem. BGO
builds a probabilistic surrogate of the expensive objective function and uses
it to define an information acquisition function (IAF) whose role is to
quantify the merit of making new objective evaluations. Specifically, BGO
iterates between making the observations with the largest expected IAF and
rebuilding the probabilistic surrogate, until a convergence criterion is met.
In this work, we extend the expected improvement (EI) IAF to the case of design
optimization under uncertainty wherein the EI policy is reformulated to filter
out parametric and measurement uncertainties. To increase the robustness of our
approach in the low sample regime, we employ a fully Bayesian interpretation of
Gaussian processes by constructing a particle approximation of the posterior of
its hyperparameters using adaptive Markov chain Monte Carlo. We verify and
validate our approach by solving two synthetic optimization problems under
uncertainty and demonstrate it by solving the oil-well-placement problem with
uncertainties in the permeability field and the oil price time series.


title: Gauge $U(1)$ Dark Symmetry and Radiative Light Fermion Masses

abstract:
  A gauge $U(1)$ family symmetry is proposed, spanning the quarks and leptons
as well as particles of the dark sector. The breaking of $U(1)$ to $Z_2$
divides the two sectors and generates one-loop radiative masses for the first
two families of quarks and leptons, as well as all three neutrinos. We study
the phenomenological implications of this new connection between family
symmetry and dark matter. In particular, a scalar or pseudoscalar particle
associated with this $U(1)$ breaking may be identified with the 750 GeV
diphoton resonance recently observed at the Large Hadron Collider (LHC).


title:
Incommensurate Magnetic Structure in the Cubic Noncentrosymmetric
  Ternary Compound Pr5Ru3Al2

abstract:
  We performed magnetic susceptibility and neutron powder diffraction
experiments on the ternary compound Pr5Ru3Al2. It belongs to the
noncentrosymmetric and nonmirrorsymmetric cubic I213 space group. The
previously reported ferromagnetic transition at 24 K was not detected in our
improved quality samples. Instead, magnetic ordering was observed in the DC
magnetic susceptibility at 3.8 K. Neutron powder diffraction further indicates
that an incommensurate magnetic structure is established below 3.8 K, with the
magnetic modulation vector (0.066, 0.066, 0.066) (r.l.u.). Using the magnetic
representation analysis, we propose the block helical structure as a candidate
for the incommensurate magnetic structure.


title: Anomalous Top and Bottom Yukawa Couplings and LHC Run 1 Data

abstract:
  In some extensions of the Standard Model, Yukawa couplings of the physical
Higgs boson can be deviated from those in the Standard Model. We study a
possibility whether or not such anomalous Yukawa couplings are consistent with
the LHC Run 1 data. It is found that sizable deviations of top and bottom (and
tau) Yukawa couplings from the Standard Model predictions can nicely fit the
data. New physics beyond the Standard Model can be revealed through more
precise measurements of such anomalous Yukawa couplings at the LHC Run 2 in the
near future. We also discuss a simple setup which can leads to anomalous Yukawa
couplings.


title: Use of Non-Orthogonal Multiple Access in Dual-hop relaying

abstract:
  To improve the sum-rate (SR) of the dual-hop relay system, a novel two-stage
power allocation scheme with non-orthogonal multiple access (NOMA) is proposed.
In this scheme, after the reception of the superposition coded symbol with a
power allocation from the source, the relay node forwards a new superposition
coded symbol with another power allocation to the destination. By employing the
maximum ratio combination (MRC), the destination jointly decodes the
information symbols from the source and the relay. Assuming Rayleigh fading
channels, closed-form solution of the ergodic SR at high signal-to-noise ratio
(SNR) is derived and a practical power allocation is also designed for the
proposed NOMA scheme. Through numerical results, it is shown that the
performance of the proposed scheme is significantly improved compared with the
existing work.


title: The trace of modular forms and its application to number theory

abstract:
  We provide a generalization of an algebraic linear combination for the trace
of certain elliptic modular forms, and through specializing the expression at a
suitable pair consisting of an elliptic curve over algebraic number fields and
its a certain cyclic subgroup with finite order, show a formula between
distinct algebraic number fields, the one related to modular forms and the
other related to elliptic curves.


title:
Growth of torsion of elliptic curves with odd-order torsion over
  quadratic cyclotomic fields

abstract:
  Let $K = \mathbb{Q}(\sqrt{-3})$ or $\mathbb{Q}(\sqrt{-1})$ and let $C_n$
denote the cyclic group of order $n$. We study how the torsion part of an
elliptic curve over $K$ grows in a quadratic extension of $K$. In the case
$E(K)[2] \approx C_1$ we investigate how a given torsion structure can grow in
a quadratic extension and the maximum number of extensions in which it grows.
We also study the torsion structures which occur as the quadratic twist of a
given torsion structure. In order to achieve this we examine $N$-isogenies
defined over $K$ for $N=15,20,21,24,27,30,35$.


title: On the complexity of computing prime tables on a Turing machine

abstract:
  We prove that the complexity of computing the table of primes between $1$ and
$n$ on a multitape Turing machine is $O(n \log n)$.


title:
Quasi-compactness of N\'eron models, and an application to torsion
  points

abstract:
  We prove that N\'eron models of jacobians of generically-smooth nodal curves
over bases of arbitrary dimension are quasi-compact (hence of finite type)
whenever they exist. We give a simple application to the orders of torsion
subgroups of jacobians over number fields.


title: High-Mass Star Formation

abstract:
  A review on current theories and observations of high-mass star formation is
given. Particularly the influence of magnetic fields and feedback mechanisms,
and of varying initial conditions on theories are discussed. The, in my biased
view, most important observations to put strong constraints on models of
high-mass star formation are pres ented, in particular bearing on the existence
and properties of high-mass starless cores, the role of filaments in the mass
transport to high-mass cores, and the propertie s of disks around high-mass
stars.


title: Notes on Cosmic Censorship Conjecture revisited: Covariantly

abstract:
  In this paper we study the dynamics of the trapped region using a frame
independent semi-tetrad covariant formalism for general Locally Rotationally
Symmetric (LRS) class II spacetimes. We covariantly prove some important
geometrical results for the apparent horizon, and state the necessary and
sufficient conditions for a singularity to be locally naked. These conditions
bring out, for the first time in a quantitative and transparent manner, the
importance of the Weyl curvature in deforming and delaying the trapped region
during continual gravitational collapse, making the central singularity locally
visible.


title: Instanton-torus knot duality in 5d SQED and $SU(2)$ SQCD

abstract:
  We briefly review the instanton-torus knot duality found in 5d SUSY gauge
theories with one compact dimension. The fermion condensate turn out to be the
generating function for the torus knot polynomials colored by the fundamental
representation.

categories: hep-th cond-mat.str-el hep-ph math-ph math.MP


title: On the Gauss-Chern-Bonnet theorem for the noncommutative 4-sphere

abstract:
  We construct a differential calculus over the noncommutative 4-sphere in the
framework of pseudo-Riemannian calculi, and show that for every metric in a
conformal class of perturbations of the round metric, there exists a unique
metric and torsion-free connection. Furthermore, we find a localization of the
projective module corresponding to the space of vector fields, which allows us
to formulate a Gauss-Chern-Bonnet type theorem for the noncommutative 4-sphere.


title:
Design and Analysis of Transmit Beamforming for Millimetre Wave Base
  Station Discovery

abstract:
  In this paper, we develop an analytical framework for the initial access
(a.k.a. Base Station (BS) discovery) in a millimeter-wave (mm-wave)
communication system and propose an effective strategy for transmitting the
Reference Signals (RSs) used for BS discovery. Specifically, by formulating the
problem of BS discovery at User Equipments (UEs) as hypothesis tests, we derive
a detector based on the Generalised Likelihood Ratio Test (GLRT) and
characterise the statistical behaviour of the detector. The theoretical results
obtained allow analysis of the impact of key system parameters on the
performance of BS discovery, and show that RS transmission with narrow beams
may not be helpful in improving the overall BS discovery performance due to the
cost of spatial scanning. Using the method of large deviations, we identify the
desirable beam pattern that minimises the average miss-discovery probability of
UEs within a targeted detectable region. We then propose to transmit the RS
with sequential scanning, using a pre-designed codebook with narrow and/or wide
beams to approximate the desirable patterns. The proposed design allows
flexible choices of the codebook sizes and the associated beam widths to better
approximate the desirable patterns. Numerical results demonstrate the
effectiveness of the proposed method.


title: Interplay of flux guiding and Hall effect in Nb films with nanogrooves

abstract:
  The interplay between vortex guiding and the Hall effect in superconducting
Nb films with periodically arranged nanogrooves is studied via four-probe
measurements in standard and Hall configurations and accompanying theoretical
modeling. The nanogrooves are milled by focused ion beam and induce a symmetric
pinning potential of the washboard type. The resistivity tensor of the films is
determined in the limit of small current densities at temperatures close to the
critical temperature for the fundamental matching configuration of the vortex
lattice with respect to the pinning nanolandscape. The angle between the
current direction with respect to the grooves is set at seven fixed values
between $0^\circ$ and $90^\circ$. A sign change is observed in the temperature
dependence of the Hall resistivity $\rho_\perp^-$ of as-grown films in a narrow
temperature range near $T_c$. By contrast, for all nanopatterned films
$\rho_\perp^-$ is nonzero in a broader temperature range below $T_c$, allowing
us to discriminate between two contributions in $\rho_\perp^-$, namely one
contribution originating from the guided vortex motion and the other one caused
by the Hall anomaly just as in as-grown Nb films. All four measured resistivity
components are successfully fitted to analytical expressions derived within the
framework of a stochastic model of competing isotropic and anisotropic pinning.
This provides evidence of the model validity for the description of the
resistive response of superconductor thin films with washboard pinning
nanolandscapes.


title: Control System Design for Tricopter using Filters and PID controller

abstract:
  The purpose of this paper is to present the control system design of
Tricopter. We have presented the implementation of control system in software
in this paper. Tricopter's control system mainly consists of two parts
Complimentary filter and PID block. The angles along X, Y and Z axis are taken
from the complementary filter which acts as a feedback block. We have used the
combination of gyroscope and accelerometer for finding the angle. We have also
shown the role of the complimentary filter in finding out the angle along X, Y,
and Z axis instead of using gyroscope and accelerometer directly. The second
main part is the PID Controller which calculates the error in angle along X, Y
and Z axis and produces an output signal which reduces error. We have shown the
importance of the constant parameters of PID Controller. The results of this
paper are tested on an actual Tricopter and also plotted in the form of graph
using Matlab and Processing software.


title: Strongly Spinor Ferromagnetic Bose Gases

abstract:
  By studying the zero-temperature and nonzero-temperature phase diagrams of
the ferromagnetic spin-1 Bose-Hubbard model under an external magnetic field,
we find that the competition between ferromagnetism and the quadratic Zeeman
energy yields two superfluid phases, which feature discontinuous first-order
phase transitions between them for a strongly spinor Bose gas such as ${}^7$Li,
contrary to the corresponding continuum system.


title: Polytopality of Maniplexes

abstract:
  Given an abstract polytope $\cal P$, its flag graph is the edge-coloured
graph whose vertices are the flags of $\cal P$ and the $i$-edges correspond to
$i$-adjacent flags. Flag graphs of polytopes are maniplexes. On the other hand,
given a maniplex $\cal M$, on can define a poset $\cal P_M$ by means of the non
empty intersection of its faces. In this paper we give necessary and sufficient
conditions (in terms of graphs) on a maniplex $\cal M$ in order for $\cal P_M$
to be an abstract polytope. Moreover, in such case, we show that $\cal M$ is
isomorphic to the flag graph of $\cal P_M$. This in turn gives necessary and
sufficient conditions for a maniplex to be (isomorphic to) the flag graph of a
polytope.


title: Quasi-classical generalized CRF structures

abstract:
  In an earlier paper, we studied manifolds $M$ endowed with a generalized F
structure $\Phi\in End(TM\oplus T^*M)$, skew-symmetric with respect to the
pairing metric, such that $\Phi^3+\Phi=0$. Furthermore, if $\Phi$ is integrable
(in some well-defined sense), $\Phi$ is a generalized CRF structure. In the
present paper we study quasi-classical generalized F and CRF structures, which
may be seen as a generalization of the holomorphic Poisson structures (it is
well known that the latter may also be defined via generalized geometry). The
structures that we study are equivalent to a pair of tensor fields $(A\in
End(TM),\pi\in\wedge^2TM)$ where $A^3+A=0$ and some relations between $A$ and
$\pi$ hold. We establish the integrability conditions in terms of $(A,\pi)$.
They include the facts that $A$ is a classical CRF structure, $\pi$ is a
Poisson bivector field and $im\,A$ is a (non)holonomic Poisson submanifold of
$(M,\pi)$. We discuss the case where either $ker\,A$ or $im\,A$ is tangent to a
foliation and, in particular, the case of almost contact manifolds. Finally, we
show that the dual bundle of $im\,A$ inherits a Lie algebroid structure and we
briefly discuss the Poisson cohomology of $\pi$, including an associated
spectral sequence and a Dolbeault type grading.


title:
An Efficient Algorithm for Mining Frequent Sequence with Constraint
  Programming

abstract:
  The main advantage of Constraint Programming (CP) approaches for sequential
pattern mining (SPM) is their modularity, which includes the ability to add new
constraints (regular expressions, length restrictions, etc). The current best
CP approach for SPM uses a global constraint (module) that computes the
projected database and enforces the minimum frequency; it does this with a
filtering algorithm similar to the PrefixSpan method. However, the resulting
system is not as scalable as some of the most advanced mining systems like
Zaki's cSPADE. We show how, using techniques from both data mining and CP, one
can use a generic constraint solver and yet outperform existing specialized
systems. This is mainly due to two improvements in the module that computes the
projected frequencies: first, computing the projected database can be sped up
by pre-computing the positions at which an symbol can become unsupported by a
sequence, thereby avoiding to scan the full sequence each time; and second by
taking inspiration from the trailing used in CP solvers to devise a
backtracking-aware data structure that allows fast incremental storing and
restoring of the projected database. Detailed experiments show how this
approach outperforms existing CP as well as specialized systems for SPM, and
that the gain in efficiency translates directly into increased efficiency for
other settings such as mining with regular expressions.


title:
Realistic description of the rotational bands in rare earth nuclei by
  angular-momentum-projected multi-cranked configuration-mixing method

abstract:
  Recently we have proposed a reliable method to describe the rotational band
in a fully microscopic manner. The method has recourse to the
configuration-mixing of several cranked mean-field wave functions after the
angular-momentum-projection. By applying the method with the Gogny D1S force as
an effective interaction, we investigate the moments of inertia of the ground
state rotational bands in a number of selected nuclei in the rare earth region.
As another application we try to describe, for the first time, the two-neutron
aligned band in $^{164}$Er, which crosses the ground state band and becomes the
yrast states at higher spins. Fairly good overall agreements with the
experimental data are achieved; for nuclei, where the pairing correlations are
properly described, the agreements are excellent. This confirms that the
previously proposed method is really useful for study of the nuclear rotational
motion.


title: An Estimation of the Size of Non-Compact Suffix Trees

abstract:
  A suffix tree is a data structure used mainly for pattern matching. It is
known that the space complexity of simple suffix trees is quadratic in the
length of the string. By a slight modification of the simple suffix trees one
gets the compact suffix trees, which have linear space complexity. The
motivation of this paper is the question whether the space complexity of simple
suffix trees is quadratic not only in the worst case, but also in expectation.


title: A Fast Incremental BSP Tree Archive for Non-dominated Points

abstract:
  Maintaining an archive of all non-dominated points is a standard task in
multi-objective optimization. Sometimes it is sufficient to store all evaluated
points and to obtain the non-dominated subset in a post-processing step.
Alternatively the non-dominated set can be updated on the fly. While keeping
track of many non-dominated points efficiently is easy for two objectives, we
propose an efficient algorithm based on a binary space partitioning (BSP) tree
for the general case of three or more objectives. Our analysis and our
empirical results demonstrate the superiority of the method over the
brute-force baseline method, as well as graceful scaling to large numbers of
objectives.


title:
Accurate and scalable social recommendation using mixed-membership
  stochastic block models

abstract:
  With ever-increasing amounts of online information available, modeling and
predicting individual preferences-for books or articles, for example-is
becoming more and more important. Good predictions enable us to improve advice
to users, and obtain a better understanding of the socio-psychological
processes that determine those preferences. We have developed a collaborative
filtering model, with an associated scalable algorithm, that makes accurate
predictions of individuals' preferences. Our approach is based on the explicit
assumption that there are groups of individuals and of items, and that the
preferences of an individual for an item are determined only by their group
memberships. Importantly, we allow each individual and each item to belong
simultaneously to mixtures of different groups and, unlike many popular
approaches, such as matrix factorization, we do not assume implicitly or
explicitly that individuals in each group prefer items in a single group of
items. The resulting overlapping groups and the predicted preferences can be
inferred with a expectation-maximization algorithm whose running time scales
linearly (per iteration). Our approach enables us to predict individual
preferences in large datasets, and is considerably more accurate than the
current algorithms for such large datasets.


title: Sparse Recovery from Extreme Eigenvalues Deviation Inequalities

abstract:
  This article provides a new toolbox to derive sparse recovery guarantees from
small deviations on extreme singular values or extreme eigenvalues obtained in
Random Matrix Theory. This work is based on Restricted Isometry Constants
(RICs) which are a pivotal notion in Compressed Sensing and High-Dimensional
Statistics as these constants finely assess how a linear operator is
conditioned on the set of sparse vectors and hence how it performs in SRSR.
While it is an open problem to construct deterministic matrices with apposite
RICs, one can prove that such matrices exist using random matrices models. In
this paper, we show upper bounds on RICs for Gaussian and Rademacher matrices
using state-of-the-art small deviation estimates on their extreme eigenvalues.
This allows us to derive a lower bound on the probability of getting SRSR. One
benefit of this paper is a direct and explicit derivation of upper bounds on
RICs and lower bounds on SRSR from small deviations on the extreme eigenvalues
given by Random Matrix theory.

categories: math.ST cs.IT math.IT math.PR stat.ML stat.TH


title:
On the excursions of drifted Brownian motion and the successive passage
  times of Brownian motion

abstract:
  By using the law of the excursions of Brownian motion with drift, we find the
distribution of the $n-$th passage time of Brownian motion through a straight
line $S(t)= a + bt.$ In the special case when $b = 0,$ we extend the result to
a space-time transformation of Brownian motion.


title: Strong modularity of reducible Galois representations

abstract:
  In this paper, we call strongly modular those reducible semi-simple odd mod
$l$ Galois representations for which the conclusion of the strongest form of
Serre's original modularity conjecture holds. Under the assumption that the
Serre weight $k$ satisfies $l\textgreater{}k+1$, we give a precise
characterization of strongly modular representations, hence generalizing a
classical theorem of Ribet pertaining to the case of conductor $1$.When the
representation $\rho$ is not strongly modular, we give a necessary and
sufficient condition on the primes $p$ not dividing $Nl$ for which it arises in
level $Np$, where $N$ denotes the conductor of $\rho$. This generalizes a
result of Mazur on the case $(N,k)=(1,2)$.


title:
Strong convergence for the Euler-Maruyama approximation of stochastic
  differential equations with discontinuous coefficients

abstract:
  In this paper we study the strong convergence for the Euler-Maruyama
approximation of a class of stochastic differential equations whose both drift
and diffusion coefficients are possibly discontinuous.


title: On the Combinatorial Complexity of Approximating Polytopes

abstract:
  Approximating convex bodies succinctly by convex polytopes is a fundamental
problem in discrete geometry. A convex body $K$ of diameter $\mathrm{diam}(K)$
is given in Euclidean $d$-dimensional space, where $d$ is a constant. Given an
error parameter $\varepsilon > 0$, the objective is to determine a polytope of
minimum combinatorial complexity whose Hausdorff distance from $K$ is at most
$\varepsilon \cdot \mathrm{diam}(K)$. By combinatorial complexity we mean the
total number of faces of all dimensions of the polytope. A well-known result by
Dudley implies that $O(1/\varepsilon^{(d-1)/2})$ facets suffice, and a dual
result by Bronshteyn and Ivanov similarly bounds the number of vertices, but
neither result bounds the total combinatorial complexity. We show that there
exists an approximating polytope whose total combinatorial complexity is
$\tilde{O}(1/\varepsilon^{(d-1)/2})$, where $\tilde{O}$ conceals a
polylogarithmic factor in $1/\varepsilon$. This is a significant improvement
upon the best known bound, which is roughly $O(1/\varepsilon^{d-2})$.
  Our result is based on a novel combination of both old and new ideas. First,
we employ Macbeath regions, a classical structure from the theory of convexity.
The construction of our approximating polytope employs a new stratified
placement of these regions. Second, in order to analyze the combinatorial
complexity of the approximating polytope, we present a tight analysis of a
width-based variant of B\'{a}r\'{a}ny and Larman's economical cap covering.
Finally, we use a deterministic adaptation of the witness-collector technique
(developed recently by Devillers et al.) in the context of our stratified
construction.


title: Unitary stable ranks and norm-one ranks

abstract:
  In the context of commutative $C^*$-algebras we solve a problem related to a
question of M. Rieffel by showing that the all-units rank and the norm-one rank
coincide with the topological stable rank. We also introduce the notion of
unitary $M$-stable rank for an arbitrary commutative unital ring and compare it
with the Bass stable rank. In case of uniform algebras, a sufficient condition
for norm-one reducibility is given.


title:
Observational detection of drift velocity between ionized and neutral
  species in solar prominences

abstract:
  We report a detection of differences in ion and neutral velocities in
prominences using high resolution spectral data obtained in September 2012 at
the German Vacuum Tower Telescope (Observatorio del Teide, Tenerife). A time
series of scans of a small portion of a solar prominence was obtained
simultaneously with a high cadence using the lines of two elements with
different ionization states, namely the CaII 8542 A and the HeI 10830 A.
Displacements, widths and amplitudes of both lines were carefully compared to
extract dynamical information about the plasma. Many dynamical features are
detected, such as counterstreaming flows, jets and propagating waves. In all
the cases we find very strong correlation between the parameters extracted from
the lines of both elements, confirming that both trace the same plasma.
Nevertheless, we also find short-lived transients where this correlation is
lost. These transients are associated with the ion-neutral drift velocities of
the order of several hundred m/s. The patches of non-zero drift velocity show
coherence on time-distance diagrams.


title:
Modeling Relational Information in Question-Answer Pairs with
  Convolutional Neural Networks

abstract:
  In this paper, we propose convolutional neural networks for learning an
optimal representation of question and answer sentences. Their main aspect is
the use of relational information given by the matches between words from the
two members of the pair. The matches are encoded as embeddings with additional
parameters (dimensions), which are tuned by the network. These allows for
better capturing interactions between questions and answers, resulting in a
significant boost in accuracy. We test our models on two widely used answer
sentence selection benchmarks. The results clearly show the effectiveness of
our relational information, which allows our relatively simple network to
approach the state of the art.


title:
Practical splitting methods for the adaptive integration of nonlinear
  evolution equations. Part I: Construction of optimized schemes and pairs of
  schemes

abstract:
  We present a number of new contributions to the topic of constructing
efficient higher-order splitting methods for the numerical integration of
evolution equations. Particular schemes are constructed via setup and solution
of polynomial systems for the splitting coefficients. To this end we use and
modify a recent approach for generating these systems for a large class of
splittings. In particular, various types of pairs of schemes intended for use
in adaptive integrators are constructed.


title:
Micromagnetic simulation of exchange coupled ferri-/ferromagnetic
  composite in bit patterned media

abstract:
  Ferri-/ferromagnetic exchange coupled composites are promising candidates for
bit patterned media because of the ability to control the magnetic properties
of the ferrimagnet by its composition. A micromagnetic model for the bilayer
system is presented where we also incorporate the microstructural features of
both layers. Micromagnetic finite element simulations are performed to
investigate the magnetization reversal behaviour of such media. By adding the
exchange coupled ferrimagnet to the ferromagnet, the switching field could be
reduced by up to $40\,\%$ and also the switching field distribution is
narrowed. To reach these significant improvements, an interface exchange
coupling strength of $2\,\mathrm{mJ/m^2}$ is required.


title: Horizon Shells: Classical Structure at the Horizon of a Black Hole

abstract:
  We address the question of the uniqueness of the Schwarzschild black hole by
considering the following question: How many meaningful solutions of the
Einstein equations exist that agree with the Schwarzschild solution (with a
fixed mass m) everywhere except maybe on a codimension one hypersurface? The
perhaps surprising answer is that the solution is unique (and uniquely the
Schwarzschild solution everywhere in spacetime) *unless* the hypersurface is
the event horizon of the Schwarzschild black hole, in which case there are
actually an infinite number of distinct solutions. We explain this result and
comment on some of the possible implications for black hole physics.


title:
Solution of the initial value problem for the focusing Davey-Stewartson
  II system

abstract:
  We consider a focusing Davey-Stewartson system and construct the solution of
the Cauchy problem in the possible presence of exceptional points (and/or
curves).


title: Approximate Polytope Membership Queries

abstract:
  In the polytope membership problem, a convex polytope $K$ in $\mathbb{R}^d$
is given, and the objective is to preprocess $K$ into a data structure so that,
given any query point $q \in \mathbb{R}^d$, it is possible to determine
efficiently whether $q \in K$. We consider this problem in an approximate
setting. Given an approximation parameter $\varepsilon$, the query can be
answered either way if the distance from $q$ to $K$'s boundary is at most
$\varepsilon$ times $K$'s diameter. We assume that the dimension $d$ is fixed,
and $K$ is presented as the intersection of $n$ halfspaces. Previous solutions
to approximate polytope membership were based on straightforward applications
of classic polytope approximation techniques by Dudley (1974) and Bentley et
al. (1982). The former is optimal in the worst-case with respect to space, and
the latter is optimal with respect to query time.
  We present four main results. First, we show how to combine the two above
techniques to obtain a simple space-time trade-off. Second, we present an
algorithm that dramatically improves this trade-off. In particular, for any
constant $\alpha \ge 4$, this data structure achieves query time
$O(1/\varepsilon^{(d-1)/\alpha})$ and space roughly $O(1/\varepsilon^{(d-1)(1 -
O(\log \alpha)/\alpha)})$. We do not know whether this space bound is tight,
but our third result shows that there is a convex body such that our algorithm
achieves a space of at least $\Omega(
1/\varepsilon^{(d-1)(1-O(\sqrt{\alpha})/\alpha} )$. Our fourth result shows
that it is possible to reduce approximate Euclidean nearest neighbor searching
to approximate polytope membership queries. Combined with the above results,
this provides significant improvements to the best known space-time trade-offs
for approximate nearest neighbor searching in $\mathbb{R}^d$.


title: Eilenberg--Moore Monoids and Backtracking Monad Transformers

abstract:
  We develop an algebraic underpinning of backtracking monad transformers in
the general setting of monoidal categories. As our main technical device, we
introduce Eilenberg--Moore monoids, which combine monoids with algebras for
strong monads. We show that Eilenberg--Moore monoids coincide with algebras for
the list monad transformer ('done right') known from Haskell libraries.
  From this, we obtain a number of results, including the facts that the list
monad transformer is indeed a monad, a transformer, and an instance of the
MonadPlus class. Finally, we construct an Eilenberg--Moore monoid of
endomorphisms, which, via the codensity monad construction, yields a
continuation-based implementation a la Hinze.


title: SMT Solving for Functional Programming over Infinite Structures

abstract:
  We develop a simple functional programming language aimed at manipulating
infinite, but first-order definable structures, such as the countably infinite
clique graph or the set of all intervals with rational endpoints. Internally,
such sets are represented by logical formulas that define them, and an external
satisfiability modulo theories (SMT) solver is regularly run by the interpreter
to check their basic properties.
  The language is implemented as a Haskell module.


title: Variations on Noetherianness

abstract:
  In constructive mathematics, several nonequivalent notions of finiteness
exist. In this paper, we continue the study of Noetherian sets in the
dependently typed setting of the Agda programming language. We want to say that
a set is Noetherian, if, when we are shown elements from it one after another,
we will sooner or later have seen some element twice. This idea can be made
precise in a number of ways. We explore the properties and connections of some
of the possible encodings. In particular, we show that certain implementations
imply decidable equality while others do not, and we construct counterexamples
in the latter case. Additionally, we explore the relation between
Noetherianness and other notions of finiteness.


title: Directed Containers as Categories

abstract:
  Directed containers make explicit the additional structure of those
containers whose set functor interpretation carries a comonad structure. The
data and laws of a directed container resemble those of a monoid, while the
data and laws of a directed container morphism those of a monoid morphism in
the reverse direction. With some reorganization, a directed container is the
same as a small category, but a directed container morphism is opcleavage-like.
We draw some conclusions for comonads from this observation, considering in
particular basic constructions and concepts like the opposite category and a
groupoid.


title: Ab Initio Theory of Coherent Laser-Induced Magnetization in Metals

abstract:
  We present the first materials specific ab initio theory of the magnetization
induced by circularly polarized laser light in metals. Our calculations are
based on non-linear density matrix theory and include the effect of absorption.
We show that the induced magnetization, commonly referred to as inverse Faraday
effect, is strongly materials and frequency dependent, and demonstrate the
existence of both spin and orbital induced magnetizations which exhibit a
surprisingly different behavior. We show that for nonmagnetic metals (as Cu,
Au, Pd, Pt) and antiferromagnetic metals the induced magnetization is
antisymmetric in the light's helicity, whereas for ferromagnetic metals (Fe,
Co, Ni, FePt) the imparted magnetization is only asymmetric in the helicity. We
compute effective optomagnetic fields that correspond to the induced
magnetizations and provide guidelines for achieving all-optical
helicity-dependent switching.


title: Multiparticle production: an old-fashioned view

abstract:
  We consider the dynamics of high energy multiparticle production and discuss
how the space-time picture of inelastic interaction may reveal itself in
identical particles Bose-Einstein correlations.


title: The BCH-Formula and Order Conditions for Splitting Methods

abstract:
  As an application of the BCH-formula, order conditions for splitting schemes
are derived. The same conditions can be obtained by using non-commutative power
series techniques and inspecting the coefficients of Lyndon-Shirshov words.


title:
Functional mixed effects wavelet estimation for spectra of replicated
  time series

abstract:
  Motivated by spectral analysis of replicated brain signal time series, we
propose a functional mixed effects approach to model replicate-specific
spectral densities as random curves varying about a deterministic
population-mean spectrum. In contrast to existing work, we do not assume the
replicate-specific spectral curves to be independent, i.e. there may exist
explicit correlation between different replicates in the population. By
projecting the replicate-specific curves onto an orthonormal wavelet basis,
estimation and prediction is carried out under an equivalent linear mixed
effects model in the wavelet coefficient domain. To cope with potentially very
localized features of the spectral curves, we develop estimators and predictors
based on a combination of generalized least squares estimation and nonlinear
wavelet thresholding, including asymptotic confidence sets for the
population-mean curve. We derive risk bounds for the nonlinear wavelet
estimator of the population-mean curve, a result that reflects the influence of
correlation between different curves in the replicate-population, and we derive
consistency of the estimators of the inter- and intra-curve correlation
structure in an appropriate sparseness class of functions. To illustrate the
proposed functional mixed effects model and our estimation and prediction
procedures, we present several simulated time series data examples and we
analyze a motivating brain signal dataset recorded during an associative
learning experiment.


title:
Spectral lags of flaring events in $LSI +61^{o} $ 303 from RXTE
  Observations

abstract:
  This work reports the first discovery of (negative) spectral lags in the
X-ray emission below 10 keV from the gamma ray binary $LSI +61^{o} $ 303 during
large flaring episodes using the Rossi X-ray Timing Explorer (RXTE)
observations. It is found from the RXTE data that during the flares, low energy
(3-5 KeV) variations lead the higher energy (8-10 keV) variations by few tens
of seconds whereas no significant time lag is observed during the non-flaring
states. The observed spectral lag features for flaring events suggest that
inverse Compton scattering may be operative, at least in some part of the
system. Another possibility is that the sites of particle acceleration may be
different for flaring and non-flaring events such as in the microquasar model
the flaring radiation may come from hot spots sitting above the black hole
while steady state emissions are due to the jets.


title:
$D^\ast_{s0}(2317)$ and $DK$ scattering in $B$ decays from BaBar and
  LHCb data

abstract:
  We study the experimental $DK$ invariant mass spectra of the reactions $B^+
\to \bar{D}^0 D^0 K^+$, $B^0 \to D^- D^0 K^+$ (measured by the BaBar
Collaboration) and $B_s \to \pi^+ \bar{D}^0 K^-$ (measured by the LHCb
Collaboration), where an enhancement right above the threshold is seen. We show
that this enhancement is due to the presence of $D^\ast_{s0}(2317)$, which is a
$DK$ bound state in the $I(J^P) = 0(0^+)$ sector. We employ a unitarized
amplitude with an interaction potential fixed by heavy meson chiral
perturbation theory. We obtain a mass $M_{D^\ast_{s0}} = 2315^{+12}_{-17}\
^{+10}_{-5}\ \text{MeV}$, and we also show, by means of the Weinberg
compositeness condition, that the $DK$ component in the wave function of this
state is $P_{DK} = 70^{+4}_{-6}\ ^{+4}_{-8} \%$, where the first (second) error
is statistical (systematic).


title:
Effective spin dephasing mechanism in confined two-dimensional
  topological insulators

abstract:
  A Kramers pair of helical edge states in quantum spin Hall effect (QSHE) is
robust against normal dephasing but not robust to spin dephasing. In our work,
we provide an effective spin dephasing mechanism in the puddles of
two-dimensional (2D) QSHE, which is simulated as quantum dots modeled by 2D
massive Dirac Hamiltonian. We demonstrate that the spin dephasing effect can
originate from the combination of the Rashba spin-orbit coupling and
electron-phonon interaction, which gives rise to inelastic backscattering in
edge states within the topological insulator quantum dots, although the
time-reversal symmetry is preserved throughout. Finally, we discuss the
tunneling between extended helical edge states and local edge states in the QSH
quantum dots, which leads to backscattering in the extended edge states. These
results can explain the more robust edge transport in InAs/GaSb QSH systems.


title: Applications conformes {\`a} grande {\'e}chelle

abstract:
  Roughly speaking, let us say that a map between metric spaces is large scale
conformal if it maps packings by large balls to large quasi-balls with limited
overlaps. This quasi-isometry invariant notion makes sense for finitely
generated groups. Inspired by work by Benjamini and Schramm, we show that under
such maps, some kind of dimension increases: exponent of volume growth for
nilpotent groups, conformal dimension of the ideal boundary for hyperbolic
groups. A purely metric space notion of {\ell} p-cohomology plays a key role.


title:
Phenomenological theory of optical broadening in zero-dimensional
  systems applied to silicon nanocrystals

abstract:
  We develop a phenomenological theory of inhomogeneous broadening in
zero-dimensional systems and apply it to study photoluminescence (PL) spectra
of silicon nanocrystals measured at helium and room temperatures. The proposed
approach allowed us to explain experimentally observed PL peak asymmetry,
linear dependence of the peak width on its maximum and anomalous alteration of
spectral characteristics with temperature increase.


title:
Enhanced Approximation of Labeled Multi-object Density based on
  Correlation Analysis

abstract:
  Multi-object density is a fundamental descriptor of a point process and has
ability to describe the randomness of number and values of objects, as well as
the statistical correlation between objects. Due to its comprehensive nature,
it usually has a complicate mathematical structure making the set integral
suffering from the curse of dimension and the combinatorial nature of the
problem. Hence, the approximation of multi-object density is a key research
theme in point process theory or finite set statistics (FISST). Conventional
approaches usually discard part or all of statistical correlation mechanically
in return for computational efficiency, without considering the real situation
of correlation between objects. In this paper, we propose an enhanced
approximation of labeled multi-object (LMO) density which evaluates the
correlation between objects adaptively and factorizes the LMO density into
densities of several independent subsets according to the correlation analysis.
Besides, to get a tractable factorization of LMO density, we derive the set
marginal density of any subset of the universal labeled RFS, the generalized
labeled multi-Bernoulli (GLMB) RFS family and its subclasses. The proposed
method takes into account the simplification of the complicate structure of LMO
density and the reservation of necessary correlation at the same time.


title: Towards Realistic Time-Resolved Simulations of Quantum Devices

abstract:
  We report on our recent efforts to perform realistic simulations of large
quantum devices in the time domain. In contrast to d.c. transport where the
calculations are explicitly performed at the Fermi level, the presence of
time-dependent terms in the Hamiltonian makes the system inelastic so that it
is necessary to explicitly enforce the Pauli principle in the simulations. We
illustrate our approach with calculations for a flying qubit interferometer, a
nanoelectronic device that is currently under experimental investigation. Our
calculations illustrate the fact that many degrees of freedom (16,700
tight-binding sites in the scattering region) and long simulation times (80,000
times the inverse Bandwidth of the tight-binding model) can be easily achieved
on a local computer.


title: The Closure Operator of es-Splitting Matroids

abstract:
  The es-splitting operation for binary matroids is a natural generalization of
Slater's n-line splitting operation on graphs. In this paper, we characterize
the closure operator of the es-splitting binary matroid $M^e_X$ in terms of the
closure operator of the original binary matroid $M$. We also characterize the
flats of the es-splitting binary matroid $M^e_X$ in terms of the flats of the
original binary matroid $M$.


title:
On Equivalence of Likelihood Maximization of Stochastic Block Model and
  Constrained Nonnegative Matrix Factorization

abstract:
  Community structures detection in complex network is important for
understanding not only the topological structures of the network, but also the
functions of it. Stochastic block model and nonnegative matrix factorization
are two widely used methods for community detection, which are proposed from
different perspectives. In this paper, the relations between them are studied.
The logarithm of likelihood function for stochastic block model can be
reformulated under the framework of nonnegative matrix factorization. Besides
the model equivalence, the algorithms employed by the two methods are
different. Preliminary numerical experiments are carried out to compare the
behaviors of the algorithms.


title:
Adaptive high-order splitting methods for systems of nonlinear evolution
  equations with periodic boundary conditions

abstract:
  We assess the applicability and efficiency of time-adaptive high-order
splitting methods applied for the numerical solution of (systems of) nonlinear
parabolic problems under periodic boundary conditions. We discuss in particular
several applications generating intricate patterns and displaying nonsmooth
solution dynamics. First we give a general error analysis for splitting methods
for parabolic problems under periodic boundary conditions and derive the
necessary smoothness requirements on the exact solution in particular for the
Gray-Scott equation and the Van der Pol equation. Numerical examples
demonstrate the convergence of the methods and serve to compare the efficiency
of different time-adaptive splitting schemes and of splitting into either two
or three operators, based on appropriately constructed a posteriori local error
estimators.


title:
Multi-object Tracking for Generic Observation Model Using Labeled Random
  Finite Sets

abstract:
  This paper presents an exact Bayesian filtering solution for the multi-object
tracking problem with the generic observation model. The proposed solution is
designed in the labeled random finite set framework, using the product styled
representation of labeled multi-object densities, with the standard
multi-object transition kernel and no particular simplifying assumptions on the
multi-object likelihood. Computationally tractable solutions are also devised
by applying a principled approximation involving the replacement of the full
multi-object density with a labeled multi-Bernoulli density that minimizes the
Kullback-Leibler divergence and preserves the first-order moment. To achieve
the fast performance, a dynamic grouping procedure based implementation is
presented with a step-by-step algorithm. The performance of the proposed filter
and its tractable implementations are verified and compared with the
state-of-the-art in numerical experiments.


title: Correlation lengths in hydrodynamic models of active nematics

abstract:
  We examine the scaling with activity of the emergent length scales that
control the nonequilibrium dynamics of an active nematic liquid crystal, using
two popular hydrodynamic models that have been employed in previous studies. In
both models we find that the chaotic spatio-temporal dynamics in the regime of
fully developed active turbulence is controlled by a single active scale
determined by the balance of active and elastic stresses, regardless of whether
the active stress is extensile or contractile in nature. The observed scaling
of the kinetic energy and enstropy with activity is consistent with our
single-length scale argument and simple dimensional analysis. Our results
provide a unified understanding of apparent discrepancies in the previous
literature and demonstrate that the essential physics is robust to the choice
of model.


title: Updated study of the quintuple system V994 Herculis

abstract:
  Aims: We present a new updated study of the unique quintuple system of two
eclipsing binaries, V994 Her. Methods: Based on new obtained photometric
observations, we analysed the period variations of the two eclipsing pairs of
V994 Her. Results: We found that the orbital period of the two eclipsing
binaries around a common barycenter is about 2.9 yrs instead of the original
period, which was reported as 6.3 yrs. Moreover, the system now seems to be
close to coplanar (i ~ 84deg), and we also revised the individual masses of all
four eclipsing components. The two eclipsing pairs show slow apsidal motion
with periods of about 116 and 111 yrs, respectively. Pairs A and B are distant
by about 17 mas on the sky, which is encouraging for observers because an
interferometric detection may be possible in the next years. Conclusions: All
of these results are based on the photometric observations of V994 Her and its
detailed analysis of the period changes of the two eclipsing binaries.


title:
The probability distribution functions of emission line flux
  measurements and their ratios

abstract:
  Many physical parameters in astrophysics are derived using the ratios of two
observed quantities. If the relative uncertainties on measurements are small
enough, uncertainties can be propagated analytically using simplifying
assumptions, but for large normally distributed uncertainties, the probability
distribution of the ratio become skewed, with a modal value offset from that
expected in Gaussian uncertainty propagation. Furthermore, the most likely
value of a ratio A/B is not equal to the reciprocal of the most likely value of
B/A. The effect is most pronounced when the uncertainty on the denominator is
larger than that on the numerator.
  We show that this effect is seen in an analysis of 12,126 spectra from the
Sloan Digital Sky Survey. The intrinsically fixed ratio of the [O III] lines at
4959 and 5007 ${\AA}$ is conventionally expressed as the ratio of the stronger
line to the weaker line. Thus, the uncertainty on the denominator is larger,
and non-Gaussian probability distributions result. By taking this effect into
account, we derive an improved estimate of the intrinsic 5007/4959 ratio. We
obtain a value of 3.012 $\pm$ 0.008, which is slightly but statistically
significantly higher than the theoretical value of 2.98.
  We further investigate the suggestion that fluxes measured from emission
lines at low signal to noise are strongly biased upwards. We were unable to
detect this effect in the SDSS line flux measurements, and we could not
reproduce the results of Rola and Pelat who first described this bias. We
suggest that the magnitude of this effect may depend strongly on the specific
fitting algorithm used.


title: Complex Scaling in Neutrino Mass Matrix

abstract:
  Using the residual symmetry approach, we propose a complex extension of the
scaling ansatz on $M_\nu$ which allows a nonzero mass for each of the three
light neutrinos as well as a nonvanishing $\theta_{13}$. Leptonic Dirac CP
violation must be maximal while atmospheric neutrino mixing need not to be
exactly maximal. Each of the two Majorana phases, to be probed by the search
for $0\nu \beta\beta$ decay, has to be zero or $\pi$ and a normal neutrino mass
hierarchy is allowed.