title:
HST and Spitzer point source detection and optical extinction in
  powerful narrow-line radio galaxies

abstract:
  We present the analysis of infrared HST and Spitzer data for a sample of 13
FRII radio galaxies at 0.03<z<0.11 that are classified as narrow-line radio
galaxies (NLRG). In the context of the unified schemes for active galactic
nuclei (AGN), our direct view of the AGN in NLRG is impeded by a parsec-scale
dusty torus structure. Our high resolution infrared observations provide new
information about the degree of extinction induced by the torus, and the
incidence of obscured AGN in NLRG.
  We find that the point-like nucleus detection rate increases from 25 per cent
at 1.025$\mu$m, to 80 per cent at 2.05$\mu$m, and to 100 per cent at 8.0$\mu$m.
This supports the idea that most NLRG host an obscured AGN in their centre. We
estimate the extinction from the obscuring structures using X-ray, near-IR and
mid-IR data. We find that the optical extinction derived from the 9.7$\mu$m
silicate absorption feature is consistently lower than the extinction derived
using other techniques. This discrepancy challenges the assumption that all the
mid-infrared emission of NLRG is extinguished by a simple screen of dust at
larger radii. This disagreement can be explained in terms of either weakening
of the silicate absorption feature by (i) thermal mid-IR emission from the
narrow-line region, (ii) non-thermal emission from the base of the radio jets,
or (iii) by direct warm dust emission that leaks through a clumpy torus without
suffering major attenuation.


title:
Photoelectron spin-polarization-control in the topological insulator
  Bi2Se3

abstract:
  We study the manipulation of the photoelectron spin-polarization in
Bi$_2$Se$_3$ by spin- and angle-resolved photoemission spectroscopy. General
rules are established that enable controlling the spin-polarization of
photoemitted electrons via light polarization, sample orientation, and photon
energy. We demonstrate the $\pm$100% reversal of a single component of the
measured spin-polarization vector upon the rotation of light polarization, as
well as a full three-dimensional manipulation by varying experimental
configuration and photon energy. While a material-specific density-functional
theory analysis is needed for the quantitative description, a minimal
two-atomic-layer model qualitatively accounts for the spin response based on
the interplay of optical selection rules, photoelectron interference, and
topological surface-state complex structure. It follows that photoelectron
spin-polarization control is generically achievable in systems with a
layer-dependent, entangled spin-orbital texture.


title: On the Duality of Semiantichains and Unichain Coverings

abstract:
  We study a min-max relation conjectured by Saks and West: For any two posets
$P$ and $Q$ the size of a maximum semiantichain and the size of a minimum
unichain covering in the product $P\times Q$ are equal. For positive we state
conditions on $P$ and $Q$ that imply the min-max relation. Based on these
conditions we identify some new families of posets where the conjecture holds
and get easy proofs for several instances where the conjecture had been
verified before. However, we also have examples showing that in general the
min-max relation is false, i.e., we disprove the Saks-West conjecture.


title: A note on the periodic decomposition problem for semigroups

abstract:
  Given $T_1,\dots, T_n$ commuting power-bounded operators on a Banach space we
study under which conditions the equality $\ker (T_1-\mathrm{I})\cdots
(T_n-\mathrm{I})=\ker(T_1-\mathrm{I})+\cdots +\ker (T_n-\mathrm{I})$ holds
true. This problem, known as the periodic decomposition problem, goes back to
I. Z. Ruzsa. In this short note we consider the case when $T_j=T(t_j)$,
$t_j>0$, $j=1,\dots, n$ for some one-parameter semigroup $(T(t))_{t\geq 0}$. We
also look at a generalization of the periodic decomposition problem when
instead of the cyclic semigroups $\{T_j^n:n \in \mathbb{N}\}$ more general
semigroups of bounded linear operators are considered.


title: Novel Properties of Twisted-Light Absorption

abstract:
  We discuss novel features of twisted-light absorption both by hydrogen-like
atoms and by micro-particles. First, we extend the treatment of atomic
photoexcitation by twisted photons to include atomic recoil, derive generalized
quantum selection rules and consider phenomena of forbidden atomic transitions.
Second, using the same electromagnetic potential for the twisted light beams,
we analyze the radiation pressure from these beams on micro-sized particles,
and verify that while the Poynting vector can in some circumstances point back
toward the source, a complete analysis nonetheless gives a repulsive radiation
pressure.


title: Two-temperature continuum thermomechanics of deforming amorphous solids

abstract:
  There is an ever-growing need for predictive models for the
elasto-viscoplastic deformation of solids. Our goal in this paper is to
incorporate recently developed out-of-equilibrium statistical concepts into a
thermodynamically consistent, finite-deformation, continuum framework for
deforming amorphous solids. The basic premise is that the configurational
degrees of freedom of the material --- the part of the internal energy/entropy
that corresponds to mechanically stable microscopic configurations --- are
characterized by a configurational temperature that might differ from that of
the vibrational degrees of freedom, which equilibrate rapidly with an external
heat bath. This results in an approximate internal energy decomposition into
weakly interacting configurational and vibrational subsystems, which exchange
energy following a Fourier-like law, leading to a thermomechanical framework
permitting two well-defined temperatures. In this framework, internal variables
that carry information about the state of the material equilibrate with the
configurational subsystem, are explicitly associated with energy and entropy of
their own, and couple to a viscoplastic flow rule. The coefficients that
determine the rate of flow of entropy and heat between different internal
systems are proposed to explicitly depend on the rate of irreversible
deformation. As an application of this framework, we discuss two constitutive
models for the response of glassy materials, a simple phenomenological model
and a model related to the concept of Shear-Transformation-Zones as the basis
for internal variables. The models account for several salient features of
glassy deformation phenomenology. Directions for future investigation are
briefly discussed.


title:
Measurements of Stellar Inclinations for Kepler Planet Candidates II:
  Candidate Spin-Orbit Misalignments in Single and Multiple-Transiting Systems

abstract:
  We present a test for spin-orbit alignment for the host stars of 25 candidate
planetary systems detected by the {\it Kepler} spacecraft. The inclination
angle of each star's rotation axis was estimated from its rotation period,
rotational line broadening, and radius. The rotation periods were determined
using the {\it Kepler} photometric time series. The rotational line broadening
was determined from high-resolution optical spectra with Subaru/HDS. Those same
spectra were used to determine the star's photospheric parameters (effective
temperature, surface gravity, metallicity) which were then interpreted with
stellar-evolutionary models to determine stellar radii. We combine the new
sample with the 7 stars from our previous work on this subject, finding that
the stars show a statistical tendency to have inclinations near 90$^\circ$, in
alignment with the planetary orbits. Possible spin-orbit misalignments are seen
in several systems, including three multiple-planet systems (KOI-304, 988,
2261). Ideally these systems should be scrutinized with complementary
techniques---such as the Rossiter-McLaughlin effect, starspot-crossing
anomalies or asteroseismology---but the measurements will be difficult owing to
the relatively faint apparent magnitudes and small transit signals in these
systems.


title: Lower Bound for the Multi-Field Bounce Action

abstract:
  We present a lower bound for the multi-field bounce action with a quartic
potential in the absence of gravity. We find that for a large number of fields
the lower bound decreases with the number of fields as N^{-3}. This work
clarifies previous statements made in numerical studies which found that the
bounce action scales as N^{-2.66} and discusses some subtleties of studying
field space trajectories.


title: The C*-algebras of compact transformation groups

abstract:
  We investigate the representation theory of the crossed-product C*-algebra
associated to a compact group G acting on a locally compact space X when the
stability subgroups vary discontinuously. Our main result applies when G has a
principal stability subgroup or X is locally of finite G-orbit type. Then the
upper multiplicity of the representation of the crossed product induced from an
irreducible representation V of a stability subgroup is obtained by restricting
V to a certain closed subgroup of the stability subgroup and taking the maximum
of the multiplicities of the irreducible summands occurring in the restriction
of V. As a corollary we obtain that when the trivial subgroup is a principal
stability subgroup, the crossed product is a Fell algebra if and only if every
stability subgroup is abelian. A second corollary is that the C*-algebra of the
classical motion group R^n\rtimes \SO(n) is a Fell algebra. This uses the
branching theorem for the special orthogonal group \SO(n) with respect to
\SO(n-1).


title: A Cryptographic Scheme Of Mellin Transform

abstract:
  In this paper it has been developed an algorithm for cryptography, using the
Mellin's transform. Cryptography is very important to protect data to ensure
that two people, using an insecure channel, may communicate in a secure way. In
the present age, ensure the communications will essential to shared data that
have to be protected. The original message is a plain text, and the encrypted
form as cipher text. The cipher text message contains all the information of
the plain text, but is cannot be read from a human without a key and a method
to decrypt it.


title: Correlations in double parton distributions: effects of evolution

abstract:
  We numerically investigate the impact of scale evolution on double parton
distributions, which are needed to compute multiple hard scattering processes.
Assuming correlations between longitudinal and transverse variables or between
the parton spins to be present at a low scale, we study how they are affected
by evolution to higher scales, i.e. by repeated parton emission. We find that
generically evolution tends to wash out correlations, but with a speed that may
be slow or fast depending on kinematics and on the type of correlation.
Nontrivial parton correlations may hence persist in double parton distributions
at the high scales relevant for hard scattering processes.


title:
Global Well-posedness of Strong Solutions to the 3D Primitive Equations
  with Horizontal Eddy Diffusivity

abstract:
  In this paper, we consider the initial-boundary value problem of the 3D
primitive equations for oceanic and atmospheric dynamics with only horizontal
diffusion in the temperature equation. Global well-posedness of strong
solutions are established with $H^2$ initial data.

categories: math.AP physics.ao-ph physics.flu-dyn physics.geo-ph


title: Hunting Quasi-Degenerate Higgsinos

abstract:
  We present a new strategy to uncover light, quasi-degenerate Higgsinos, a
likely ingredient in a natural supersymmetric model. Our strategy focuses on
Higgsinos with inter-state splittings of O(5-50) GeV that are produced in
association with a hard, initial state jet and decay via off-shell gauge bosons
to two or more leptons and missing energy, $pp \to j + \text{MET}\, + 2^+\,
\ell$. The additional jet is used for triggering, allowing us to significantly
loosen the lepton requirements and gain sensitivity to small inter-Higgsino
splittings. Focusing on the two-lepton signal, we find the seemingly large
backgrounds from diboson plus jet, $\bar tt$ and $Z/\gamma^* + j$ can be
reduced with careful cuts, and that fake backgrounds appear minor. For Higgsino
masses $m_{\chi}$ just above the current LEP II bound ($\mu \simeq 110\,$) GeV
we find the significance can be as high as 3 sigma at the LHC using the
existing 20 fb$^{-1}$ of 8 TeV data. Extrapolating to LHC at 14 TeV with 100
fb$^{-1}$ data, and as one example $M_1 = M_2 = 500$ GeV, we find 5 sigma
evidence for $m_{\chi} \lesssim\, 140\,$ GeV and 2 sigma evidence for $m_{\chi}
\lesssim\, 200\,$ GeV . We also present a reinterpretation of ATLAS/CMS monojet
bounds in terms of degenerate Higgsino ($\delta m_{\chi} \ll 5\,$) GeV plus jet
production. We find the current monojet bounds on $m_{\chi}$ are no better than
the chargino bounds from LEP II.


title: Structural patterns in complex systems using multidendrograms

abstract:
  Complex systems are usually represented as an intricate set of relations
between their components forming a complex graph or network. The understanding
of their functioning and emergent properties are strongly related to their
structural properties. The finding of structural patterns is of utmost
importance to reduce the problem of understanding the structure-function
relationships. Here we propose the analysis of similarity measures between
nodes using hierarchical clustering methods. The discrete nature of the
networks usually leads to a small set of different similarity values, making
standard hierarchical clustering algorithms ambiguous. We propose the use of
"multidendrograms", an algorithm that computes agglomerative hierarchical
clusterings implementing a variable-group technique that solves the
non-uniqueness problem found in the standard pair-group algorithm. This problem
arises when there are more than two clusters separated by the same maximum
similarity (or minimum distance) during the agglomerative process. Forcing
binary trees in this case means breaking ties in some way, thus giving rise to
different output clusterings depending on the criterion used. Multidendrograms
solves this problem grouping more than two clusters at the same time when ties
occur.

categories: physics.data-an cs.IR cs.SI physics.comp-ph physics.soc-ph


title: Discrete Charging in Polysilicon Gates of Single Electron Transistors

abstract:
  Low temperature electron transport measurements of single electron
transistors fabricated in advanced CMOS technology with polysilicon gates not
only exhibit clear Coulomb blockade behavior but also show a large number of
additional conductance fluctuations in the nonlinear regime. By comparison with
simulations these features are quantitatively attributed to the effects of
discretely charged islands in the polysilicon gates.


title: Where-When-What: the general relativity of space-time-property

abstract:
  We develop the general relativity of extended spacetime-property for
describing events including their properties. The anticommuting nature of
property coordinates, augmenting space-time $({\bf x},t)$, allows for the
natural emergence of generations and for the simple incorporation of gauge
fields in the spacetime-property sector. With one electric property this
results in a geometrical unification of gravity and electromagnetism, leading
to a Maxwell-Einstein Lagrangian plus a cosmological term. Addition of one
neutrinic and three chromic properties should lead to unification of gravity
with electroweak and strong interactions.


title:
The Capacity of Three-Receiver AWGN Broadcast Channels with Receiver
  Message Side Information

abstract:
  This paper investigates the capacity region of three-receiver AWGN broadcast
channels where the receivers (i) have private-message requests and (ii) know
the messages requested by some other receivers as side information. We classify
these channels based on their side information into eight groups, and construct
different transmission schemes for the groups. For six groups, we characterize
the capacity region, and show that it improves both the best known inner and
outer bounds. For the remaining two groups, we improve the best known inner
bound by using side information during channel decoding at the receivers.


title:
Contamination in the Kepler Field. Identification of 685 KOIs as False
  Positives Via Ephemeris Matching Based On Q1-Q12 Data

abstract:
  The Kepler mission has to date found almost 6,000 planetary transit-like
signals, utilizing three years of data for over 170,000 stars at extremely high
photometric precision. Due to its design, contamination from eclipsing
binaries, variable stars, and other transiting planets results in a significant
number of these signals being false positives. This directly affects the
determination of the occurrence rate of Earth-like planets in our Galaxy, as
well as other planet population statistics. In order to detect as many of these
false positives as possible, we perform ephemeris matching among all transiting
planet, eclipsing binary, and variable star sources. We find that 685 Kepler
Objects of Interest - 12% of all those analyzed - are false positives as a
result of contamination, due to 409 unique parent sources. Of these, 118 have
not previously been identified by other methods. We estimate that ~35% of KOIs
are false positives due to contamination, when performing a first-order
correction for observational bias. Comparing single-planet candidate KOIs to
multi-planet candidate KOIs, we find an observed false positive fraction due to
contamination of 16% and 2.4% respectively, bolstering the existing evidence
that multi-planet KOIs are significantly less likely to be false positives. We
also analyze the parameter distributions of the ephemeris matches and derive a
simple model for the most common type of contamination in the Kepler field. We
find that the ephemeris matching technique is able to identify low
signal-to-noise false positives that are difficult to identify with other
vetting techniques. We expect false positive KOIs to become more frequent when
analyzing more quarters of Kepler data, and note that many of them will not be
able to be identified based on Kepler data alone.


title:
Coherent control of optical injection of spin and currents in
  topological insulators

abstract:
  Topological insulators have surface states with a remarkable helical spin
structure, with promising prospects for applications in spintronics. Strategies
for generating spin polarized currents, such as the use of magnetic contacts
and photoinjection, have been the focus of extensive research. While several
optical methods for injecting currents have been explored, they have all
focused on one-photon absorption.
  Here we consider the use of both a fundamental optical field and its second
harmonic, which allows the injection of spin polarized carriers and current by
a nonlinear process involving quantum interference between one- and two-photon
absorption. General expressions are derived for the injection rates in a
generic two-band system, including those for one- and two-photon absorption
processes as well as their interference. Results are given for carrier, spin
density and current injection rates on the surface of topological insulators,
for both linearly and circularly polarized light. We identify the conditions
that would be necessary for experimentally verifying these predictions.


title:
Dynamics of the resistive state of a narrow superconducting channel in
  the ac voltage driven regime

abstract:
  Within the framework of the time-dependent Ginzburg-Landau equations, the
dynamics of the order parameter in narrow superconducting channels of different
lengths is investigated in the ac voltage-driven regime. The resistive state of
the system at low frequencies of the applied voltage is characterized by the
formation of time-periodic groups of oscillating phase-slip centers PSCs.
Increasing the frequency reduces the lifetime of these periodic groups.
Depending on the length of the channel, the ac voltage either tends to restore
the state with a single central PSC in periodic groups or minimizes the number
of forming PSCs and induces their ordering in the system. For relatively short
channels, a further increase in frequency leads to the suppression of the order
parameter without PCS formation. For the systems with the channel length
exceeding the specified limit, the formation of PSC starts after a certain time
delay which increases rapidly with frequency. The current-voltage
characteristics of a relatively short channel at different applied voltage
frequencies are calculated. It is found that the current-voltage
characteristics exhibit a step-like structure, where the height of the first
step is determined by the quadruple value of the Josephson frequency.


title: A Note on Distribution Free Symmetrization Inequalities

abstract:
  Let $X, Y$ be two independent identically distributed (i.i.d.) random
variables taking values from a separable Banach space $(\mathcal{X},
\|\cdot\|)$. Given two measurable subsets $F, K\subseteq\cal{X}$, we
established distribution free comparison inequalities between $\mathbb{P}(X\pm
Y \in F)$ and $\mathbb{P}(X-Y\in K)$. These estimates are optimal for real
random variables as well as when $\mathcal{X}=\mathbb{R}^d$ is equipped with
the $\|\cdot\|_\infty$ norm. Our approach for both problems extends techniques
developed by Schultze and Weizs\"acher (2007).


title:
Synchronized molecular dynamics simulation via macroscopic heat and
  momentum transfer: an application to polymer lubrication

abstract:
  The synchronized molecular dynamics simulation via macroscopic heat and
momentum transfer is proposed for the non-isothermal flow behaviors of complex
fluids. In this method, the molecular dynamics simulations are assigned to
small fluid elements to calculate the local stresses and temperatures and are
synchronized at certain time intervals to satisfy the macroscopic heat- and
momentum- transport equations. This method is applied to the lubrication of a
polymeric liquid composed of short chains with ten beads between parallel
plates. The rheological properties and conformation of polymer chains coupled
with the local viscous heating are investigated with a non-dimensional
parameter, i.e., the Nahme-Griffith number, which is defined by the ratio of
the viscous heating to the thermal conduction at the characteristic temperature
required to sufficiently change the viscosity. The present simulation
demonstrates that strong shear thinning and transitional behavior of the
conformation of the polymer chains occur with a rapid temperature rise when the
Nahme-Griffith number exceeds unity. The results also clarify that the
reentrant transition of the linear stress-optical relation occurs for large
shear stresses due to the coupling of the conformation of polymer chains and
heat generation under shear flows.


title:
$\alpha-\gamma$ transition in cerium: magnetic form factor and dynamic
  magnetic susceptibility in dynamical mean-field theory

abstract:
  The nature of the elemental cerium phases, undergoing an isostructural volume
collapse transition, cannot be understood using conventional solid state
concepts. Using the combination of density functional theory and dynamical
mean-field theory, we study the magnetic properties of both the $\alpha$ and
the $\gamma$ phases. We compute the magnetic form factor, and show that it is
very close to free ion behavior in both the local moment $\gamma$ phase as well
as the more itinerant $\alpha$ phase, in agreement with neutron scattering
experiments. In sharp contrast, the dynamic local magnetic susceptibility of
the two phases is strikingly different. In the $\gamma$ phase, the sharp low
energy peak due to local moment formation and consequently low Kondo
temperature dominates the spectra. In the $\alpha$ phase two broad peaks can be
identified, the first is due to Kondo screening, and the second is due to
Hund's coupling. This shows that hybridization plays a central role in the
$\alpha-\gamma$ transition in cerium, and that from the point of view of
magnetic properties, the $4f$ electrons are strongly correlated in both phases.


title:
Constraining Halo Occupation Distribution and Cosmic Growth Rate using
  Multipole Power Spectrum

abstract:
  We propose a new method of measuring halo occupation distribution (HOD)
together with cosmic growth rate using multipole components of galaxy power
spectrum P_l(k). The nonlinear redshift-space distortion due to the random
motion of satellite galaxies, i.e., Fingers-of-God, generates high-l multipole
anisotropy in galaxy clustering such as the hexadecapole (l=4) and
tetra-hexadecapole (l=6), which are sensitive to the fraction and the velocity
dispersion of satellite galaxies. Using simulated samples following the HOD of
Luminous Red Galaxies (LRGs), we find that the input HOD parameters are
successfully reproduced from P_l(k) and that high-l multipole information help
to break the degeneracy among HOD parameters. We also show that the
measurements of the cosmic growth rate as well as the satellite fraction and
velocity dispersions are significantly improved by adding the small-scale
information of high-l multipoles.


title:
Tractability through Exchangeability: A New Perspective on Efficient
  Probabilistic Inference

abstract:
  Exchangeability is a central notion in statistics and probability theory. The
assumption that an infinite sequence of data points is exchangeable is at the
core of Bayesian statistics. However, finite exchangeability as a statistical
property that renders probabilistic inference tractable is less
well-understood. We develop a theory of finite exchangeability and its relation
to tractable probabilistic inference. The theory is complementary to that of
independence and conditional independence. We show that tractable inference in
probabilistic models with high treewidth and millions of variables can be
understood using the notion of finite (partial) exchangeability. We also show
that existing lifted inference algorithms implicitly utilize a combination of
conditional independence and partial exchangeability.


title: A search for eclipsing binaries that host discs

abstract:
  We search for systems hosting eclipsing discs using a complete sample of
eclipsing binaries (EBs); those previously identified in the third phase of the
Optical Gravitational Lensing Experiment (OGLE-III). Within a subsample of
2,823 high-cadence, high-photometric precision and large eclipsing depth
detached EBs previously identified in the Large Magellanic Cloud (LMC), we find
that the skewness and kurtosis of the light curves magnitude distribution
within the primary eclipse can distinguish EBs hosting a disc from those
without. Two systems with previously identified eclipsing discs
(OGLE-LMC-ECL-11893 and OGLE-LMC-ECL-17782) are identified with near zero
skewness ($|S|<0.5$) and positive kurtosis. No additional eclipsing disc
systems were found in the OGLE-III LMC, Small Magellanic Cloud (SMC) or
Galactic Disc (GD) EB light curves. We estimate that the fraction of detached
near main-sequence LMC EBs (which have a primary with an $I$-band magnitude
brighter than $\simeq 19\,\rm{mag}$) that host a disc is approximately 1/1000.
As circumstellar disc lifetimes are short, we expected to primarily find
eclipsing discs around young stars. In addition, as there is more room for a
disc in a widely separated binary and because a disk close to a luminous star
would be above the dust sublimation temperature, we expected to primarily find
eclipsing discs in long period binaries. However, OGLE-LMC-ECL-17782 is a 13.3
day period B star system with a transient and hot ($\sim 6000\,\rm{K}$, $\sim
0.1\,\rm{AU}$ radius) disc and Scott et al. (in prep.) estimate an age of
$150\,\rm{Myr}$ for OGLE-LMC-ECL-11893. Both discs are unexpected in the EB
sample and impel explanation.


title:
The polluted atmospheres of cool white dwarfs and the magnetic field
  connection

abstract:
  We present an analysis of X-Shooter spectra of the polluted hydrogen-rich
white dwarfs (DAZ) NLTT 888 and NLTT 53908. The spectra of NLTT 53908 show
strong, Zeeman-split calcium lines (CaII H&K and Ca I $\lambda 4226$) and the
star appears to be a close relative of the polluted magnetic white dwarf (DAZH)
NLTT 10480, while the spectra of NLTT 888 show narrow lines of calcium and
iron. A comparison of the DAZ NLTT 888 and the DAZH NLTT 53908 with other class
members illustrates the diversity of environment and formation circumstances
surrounding these objects. In particular, we find that the incidence of
magnetism in old, polluted white dwarfs significantly exceeds that found in the
general white dwarf population which suggests an hypothetical link between a
crowded planetary system and magnetic field generation.


title:
Production of charged pions, kaons and protons at large transverse
  momenta in pp and Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV

abstract:
  Transverse momentum spectra of $\pi^{\pm}$, $\rm K^{\pm}$ and p($\bar{\rm
p}$) up to $p_{\rm T}$ = 20 GeV/$c$ at mid-rapidity in pp and Pb-Pb collisions
at $\sqrt{s_{\rm NN}}=$ 2.76 TeV have been measured using the ALICE detector at
the Large Hadron Collider. The proton-to-pion and the kaon-to-pion ratios both
show a distinct peak at $p_{\rm T} \approx 3 GeV/c$ in central Pb-Pb
collisions. Below the peak, $p_{\rm T}$ < 3 GeV/$c$, both ratios are in good
agreement with hydrodynamical calculations, suggesting that the peak itself is
dominantly the result of radial flow rather than anomalous hadronization
processes. For $p_{\rm T}$ > 10 GeV/$c$ particle ratios in pp and Pb-Pb
collisions are in agreement and the nuclear modification factors for
$\pi^{\pm}$, $\rm K^{\pm}$ and $\rm p$($\bar{\rm p}$) indicate that, within the
systematic and statistical uncertainties, the suppression is the same. This
suggests that the chemical composition of leading particles from jets in the
medium is similar to that of vacuum jets.


title:
Existence of non-topological solutions for a skew-symmetric Chern-Simons
  system

abstract:
  We investigate the existence of non-topological solutions $(u_1,u_2)$
satisfying
  $$u_{i}(x)=-2\beta_i\ln|x|+O(1),\quad\text{as }|x|\rightarrow +\infty,$$ such
that $\beta_i>1$ and
  $$(\beta_1-1)(\beta_2-1)>(N_1+1)(N_2+1),$$
  for a skew-symmetric Chern-Simons system. By the bubbling analysis and the
Leray-Schauder degree theory, we get the existence results except for a finite
set of curves:
$$\frac{N_1}{\beta_1+N_1}+\frac{N_2}{\beta_2+N_2}=\frac{k-1}{k},k=2,\cdots,\max(N_1,N_2).$$
This generalizes a previous work by Choe-Kim-Lin \cite{ChoeKimLin2011}.


title: Two dimensional water waves in holomorphic coordinates

abstract:
  This article is concerned with the infinite depth water wave equation in two
space dimensions. We consider this problem expressed in position-velocity
potential holomorphic coordinates. Viewing this problem as a quasilinear
dispersive equation, we establish two results: (i) local well-posedness in
Sobolev spaces, and (ii) almost global solutions for small localized data.
Neither of these results are new; they have been recently obtained by
Alazard-Burq-Zuily \cite{abz}, respectively by Wu \cite{wu} using different
coordinates and methods. Instead our goal is improve the understanding of this
problem by providing a single setting for both problems, by proving sharper
versions of the above results, as well as presenting new, simpler proofs. This
article is self contained.


title:
The Baker-Akhiezer function and factorization of the Chebotarev-Khrapkov
  matrix

abstract:
  A new technique is proposed for the solution of the Riemann-Hilbert problem
with the Chebotarev-Khrapkov matrix coefficient
$G(t)=\alpha_1(t)I+\alpha_2(t)Q(t)$, $\alpha_1(t), \alpha_2(t)\in H(L)$, $Q(t)$
is a $2\times 2$ zero-trace polynomial matrix, and $I$ is the unit matrix. This
problem has numerous applications in elasticity and diffraction theory. The
main feature of the method is the removal of the essential singularities of the
solution to the associated homogeneous scalar Riemann-Hilbert problem on the
hyperelliptic surface of an algebraic function by means of the Baker-Akhiezer
function. The consequent application of this function for the derivation of the
general solution to the vector Riemann-Hilbert problem requires finding of the
$\rho$ zeros of the Baker-Akhiezer function ($\rho$ is the genus of the
surface). These zeros are recovered through the solution to the associated
Jacobi problem of inversion of abelian integrals or, equivalently, the
determination of the zeros of the associated degree-$\rho$ polynomial and
solution of a certain linear algebraic system of $\rho$ equations.


title:
Bunch evolution study in optimization of MeV ultrafast electron
  diffraction

abstract:
  Megaelectronvolt ultrafast electron diffraction (UED) is a promising
detection tool for ultrafast processes. The quality of diffraction image is
determined by the transverse evolution of the probe bunch. In this paper, we
study the contributing terms of the emittance and space charge effects to the
bunch evolution in MeV UED scheme, employing a mean-field model with an
ellipsoidal distribution as well as particle tracking simulation. Small
transverse dimension of the drive laser is found critical to improve the
reciprocal resolution, exploiting both smaller emittance and larger transverse
bunch size before the solenoid. The degradation of reciprocal spatial
resolution caused by the space charge effects should be carefully controlled.


title: Interiors of completely positive cones

abstract:
  A symmetric matrix $A$ is completely positive (CP) if there exists an
entrywise nonnegative matrix $B$ such that $A = BB^T$. We characterize the
interior of the CP cone. A semidefinite algorithm is proposed for checking
interiors of the CP cone, and its properties are studied. A CP-decomposition of
a matrix in Dickinson's form can be obtained if it is an interior of the CP
cone. Some computational experiments are also presented.


title: Inflationary Baryogenesis in a Model with Gauged Baryon Number

abstract:
  We argue that inflationary dynamics may support a scenario where significant
matter-antimatter asymmetry is generated from initially small-scale quantum
fluctuations that are subsequently stretched out over large scales. This
scenario can be realised in extensions of the Standard Model with an extra
gauge symmetry having mixed anomalies with the electroweak gauge symmetry.
Inflationary baryogenesis in a model with gauged baryon number is considered in
detail.


title: Optimal network modularity for information diffusion

abstract:
  We investigate the impact of community structure on information diffusion
with the linear threshold model. Our results demonstrate that modular structure
may have counter-intuitive effects on information diffusion when social
reinforcement is present. We show that strong communities can facilitate global
diffusion by enhancing local, intra-community spreading. Using both analytic
approaches and numerical simulations, we demonstrate the existence of an
optimal network modularity, where global diffusion require the minimal number
of early adopters.


title: OSCAR: A Collaborative Bandwidth Aggregation System

abstract:
  The exponential increase in mobile data demand, coupled with growing user
expectation to be connected in all places at all times, have introduced novel
challenges for researchers to address. Fortunately, the wide spread deployment
of various network technologies and the increased adoption of multi-interface
enabled devices have enabled researchers to develop solutions for those
challenges. Such solutions aim to exploit available interfaces on such devices
in both solitary and collaborative forms. These solutions, however, have faced
a steep deployment barrier.
  In this paper, we present OSCAR, a multi-objective, incentive-based,
collaborative, and deployable bandwidth aggregation system. We present the
OSCAR architecture that does not introduce any intermediate hardware nor
require changes to current applications or legacy servers. The OSCAR
architecture is designed to automatically estimate the system's context,
dynamically schedule various connections and/or packets to different
interfaces, be backwards compatible with the current Internet architecture, and
provide the user with incentives for collaboration. We also formulate the OSCAR
scheduler as a multi-objective, multi-modal scheduler that maximizes system
throughput while minimizing energy consumption or financial cost. We evaluate
OSCAR via implementation on Linux, as well as via simulation, and compare our
results to the current optimal achievable throughput, cost, and energy
consumption. Our evaluation shows that, in the throughput maximization mode, we
provide up to 150% enhancement in throughput compared to current operating
systems, without any changes to legacy servers. Moreover, this performance gain
further increases with the availability of connection resume-supporting, or
OSCAR-enabled servers, reaching the maximum achievable upper-bound throughput.


title: Social dilemma alleviated by sharing the gains with immediate neighbors

abstract:
  We study the evolution of cooperation in the evolutionary spatial prisoner's
dilemma game (PDG) and snowdrift game (SG), within which a fraction $\alpha$ of
the payoffs of each player gained from direct game interactions is shared
equally by the immediate neighbors. The magnitude of the parameter $\alpha$
therefore characterizes the degree of the relatedness among the neighboring
players. By means of extensive Monte Carlo simulations as well as an extended
mean-field approximation method, we trace the frequency of cooperation in the
stationary state. We find that plugging into relatedness can significantly
promote the evolution of cooperation in the context of both studied games.
Unexpectedly, cooperation can be more readily established in the spatial PDG
than that in the spatial SG, given that the degree of relatedness and the
cost-to-benefit ratio of mutual cooperation are properly formulated. The
relevance of our model with the stakeholder theory is also briefly discussed.


title: Loop contribution to inflationary magnetic field

abstract:
  Within the framework of the standard quantum electrodynamics, we compute
contribution of vacuum polarization at one-loop order to the power spectrum of
the magnetic field on inflationary (de Sitter) background. It is found that the
one-loop term exhibits the infrared secular growth that is proportional to the
number of $e$-folds. The use of the dynamical renormalization group method,
which amounts to partial resummation of higher loop diagrams, shows that the
resummed power spectrum is free from the secular growth and the loop effect
only changes the power from $(k/a)^4$ at the tree level to ${(k/a)}^{4-\nu}$,
where $\nu$ represents the contribution from vacuum polarization. The parameter
$\nu$, being proportional to the square of the gauge coupling constant as well
as the number of fermion species, is a simple function of a ratio of fermion
mass to the Hubble parameter and is positive irrespective of the fermion mass.
Thus, the loop effect always enhances the infrared magnetic field strength. We
find that $\nu \simeq 5 \times 10^{-3}$ is the possible maximum contribution to
$\nu$ from a single fermion. This estimate suggests that either large number of
fermion species or large coupling constant is a necessary condition for the
loop effect to be responsible for the seed of the cosmic magnetic fields.


title: Good reduction criterion for K3 surfaces

abstract:
  We prove a Neron--Ogg--Shafarevich type criterion for good reduction of K3
surfaces, which states that a K3 surface over a complete discrete valuation
field has potential good reduction if its $l$-adic cohomology group is
unramified. We also prove a $p$-adic version of the criterion. (These are
analogues of the criteria for good reduction of abelian varieties.) The model
of the surface will be in general not a scheme but an algebraic space. As a
corollary of the criterion we obtain the surjectivity of the period map of K3
surfaces in positive characteristic.


title: Basin of Attraction Determines Hysteresis in Explosive Synchronization

abstract:
  Spontaneous explosive emergent behavior takes place in heterogeneous networks
when the frequencies of the nodes are positively correlated to the node degree.
A central feature of such explosive transitions is a hysteretic behavior at the
transition to synchronization. We unravel the underlying mechanisms and show
that the dynamical origin of the hysteresis is a change of basin of attraction
of the synchronization state. Our findings hold for heterogeneous networks with
star graph motifs such as scale free networks, and hence reveal how microscopic
network parameters such as node degree and frequency affect the global network
properties and can be used for network design and control.


title: More on the normalized Laplacian Estrada index

abstract:
  Let $G$ be a simple graph of order $N$. The normalized Laplacian Estrada
index of $G$ is defined as $NEE(G)=\sum_{i=1}^Ne^{\lambda_i}$, where
$\lambda_1,\lambda_2,\cdots,\lambda_N$ are the normalized Laplacian eigenvalues
of $G$. In this paper, we give a tight lower bound for $NEE$ of general graphs.
We also calculate $NEE$ for a class of treelike fractals, which contain some
classical chemical trees as special cases. It is shown that $NEE$ scales
linearly with the order of the fractal, in line with a best possible lower
bound for connected bipartite graphs.


title:
Identifiability of Subgroup Causal Effects in Randomized Experiments
  with Nonignorable Missing Covariates

abstract:
  Although randomized experiments are widely regarded as the gold standard for
estimating causal effects, missing data of the pretreatment covariates makes it
challenging to estimate the subgroup causal effects. When the missing data
mechanism of the covariates is nonignorable, the parameters of interest are
generally not pointly identifiable, and we can only get bounds for the
parameters of interest, which may be too wide for practical use. In some real
cases, we have prior knowledge that some restrictions may be plausible. We show
the identifiability of the causal effects and joint distributions for four
interpretable missing data mechanisms, and evaluate the performance of the
statistical inference via simulation studies. One application of our methods to
a real data set from a randomized clinical trial shows that one of the
nonignorable missing data mechanisms fits better than the ignorable missing
data mechanism, and the results conform to the study's original expert
opinions. We also illustrate the potential applications of our methods to
observational studies using a data set from a job-training program.


title:
Chemical compositions of six metal-poor stars in the ultra-faint dwarf
  spheroidal galaxy Bo\"otes I

abstract:
  Ultra-faint dwarf galaxies recently discovered around the Milky Way (MW)
contain extremely metal-poor stars, and might represent the building blocks of
low-metallicity components of the MW. Among them, the Bo\"otes I dwarf
spheroidal galaxy is of particular interest because of its exclusively old
stellar population. We determine chemical compositions of six red giant stars
in Bo\"otes I, based on the high-resolution spectra obtained with the High
Dispersion Spectrograph mounted on the Subaru Telescope. Abundances of 12
elements, including C, Na, alpha, Fe-peak, and neutron capture elements, were
determined for the sample stars. The abundance results were compared to those
in field MW halo stars previously obtained using an abundance analysis
technique similar to the present study. We confirm the low metallicity of
Boo-094 ([Fe/H]=-3.4). Except for this star, the abundance ratios ([X/Fe]) of
elements lighter than zinc are generally homogeneous with small scatter around
the mean values in the metallicities spanned by the other five stars
(-2.7<[Fe/H]<-1.8). Specifically, all of the sample stars with [Fe/H]>-2.7 show
no significant enhancement of carbon. The [Mg/Fe] and [Ca/Fe] ratios are almost
constant with a modest decreasing trend with increasing [Fe/H] and are slightly
lower than the field halo stars. The [Sr/Fe] and [Sr/Ba] ratios also tend to be
lower in the Bo\"otes I stars than in the halo stars. Our results of small
scatter in the [X/Fe] ratios for elements lighter than zinc suggest that these
abundances were homogeneous among the ejecta of prior generation(s) of stars in
this galaxy.


title: $\mathcal{D}$-maximal sets

abstract:
  Soare proved that the maximal sets form an orbit in $\mathcal{E}$. We
consider here $\mathcal{D}$-maximal sets, generalizations of maximal sets
introduced by Herrmann and Kummer. Some orbits of $\mathcal{D}$-maximal sets
are well understood, e.g., hemimaximal sets, but many are not. The goal of this
paper is to define new invariants on computably enumerable sets and to use them
to give a complete nontrivial classification of the $\mathcal{D}$-maximal sets.
Although these invariants help us to better understand the
$\mathcal{D}$-maximal sets, we use them to show that several classes of
$\mathcal{D}$-maximal sets break into infinitely many orbits.


title: Three Occurrences of the Hyperbolic-Secant Distribution

abstract:
  Although it is the generator distribution of the sixth natural exponential
family with quadratic variance function, the Hyperbolic-Secant distribution is
much less known than other distributions in the exponential families. Its lack
of familiarity is due to its isolation from many widely-used statistical
models. We fill in the gap by showing three examples naturally generating the
Hyperbolic-Secant distribution, including Fisher's analysis of similarity
between twins, the Jeffreys' prior for contingency tables, and invalid
instrumental variables.


title: Chaotic dynamics of the planet in HD 196885 AB

abstract:
  Depending on the planetary orbit around the host star(s), a planet could
orbit either one or both stars in a binary system as S-type or P-type,
respectively. We have analysed the dynamics of the S-type planetary system in
HD 196885 AB with an emphasis on a planet with a higher orbital inclination
relative to the binary plane. The mean exponential growth factor of nearby
orbits (MEGNO) maps are used as an indicator to determine regions of
periodicity and chaos for the various choices of the planet's semimajor axis,
eccentricity and inclination with respect to the previously determined
observational uncertainties. We have quantitatively mapped out the chaotic and
quasi-periodic regions of the system's phase space which indicate a likely
regime of the planet's inclination. In addition, we inspect the resonant angle
to determine whether alternation between libration and circulation occurs as a
consequence of Kozai oscillations, a probable mechanism that can drive the
planetary orbit to a very large inclination. Also, we demonstrate the possible
higher mass limit of the planet and improve upon the current dynamical model
based on our analysis.


title: Bayesian Robust Inference of Sample Selection Using Selection-t Models

abstract:
  Heckman selection model is the most popular econometric model in analysis of
data with sample selection. However, selection models with Normal errors cannot
accommodate heavy tails in the error distribution. Recently, Marchenko and
Genton proposed a selection-t model to perform frequentist' robust analysis of
sample selection. Instead of using their maximum likelihood estimates, our
paper develops new Bayesian procedures for the selection-t models with either
continuous or binary outcomes. By exploiting the Normal mixture representation
of the t distribution, we can use data augmentation to impute the missing data,
and use parameter expansion to sample the restricted covariance matrices. The
Bayesian procedures only involve simple steps, without calculating analytical
or numerical derivatives of the complicated log likelihood functions.
Simulation studies show the vulnerability of the selection models with Normal
errors, as well as the robustness of the selection models with t errors.
Interestingly, we find evidence of heavy-tailedness in three real examples
analyzed by previous studies, and the conclusions about the existence of
selection effect are very sensitive to the distributional assumptions of the
error terms.


title: Spherical top-hat Collapse of a Viscous Unified Dark Fluid

abstract:
  In this paper, we test the spherical collapse of a viscous unified dark fluid
(VUDF) which has constant adiabatic sound speed and show the nonlinear collapse
for VUDF, baryons, and dark matter which are important to form the large scale
structure of our Universe. By varying the values of model parameters $\alpha$
and $\zeta_{0}$, we discuss their effects on the nonlinear collapse of the VUDF
model, and compare its result to $\Lambda CDM$ model. The analyzed results show
that, within the spherical top-hat collapse framework, larger values of
$\alpha$ and smaller values of $\zeta_{0}$ make the structure formation earlier
and faster, and the other collapse curves are almost distinguished with the
curve of $\Lambda
  CDM$ model if the bulk viscosity coefficient $\zeta_{0}$ is less than
$10^{-3}$.


title:
Suppression of gravitational instabilities by dominant dark matter halo
  in low surface brightness galaxies

abstract:
  The low surface brightness galaxies are gas-rich and yet have a low star
formation rate, this is a well-known puzzle. The spiral features in these
galaxies are weak and difficult to trace, although this aspect has not been
studied much. These galaxies are known to be dominated by the dark matter halo
from the innermost regions. Here we do a stability analysis for the galactic
disc of UGC 7321, a low surface brightness, superthin galaxy, for which the
various observational input parameters are available. We show that the disc is
stable against local, linear axisymmetric and non-axisymmetric perturbations.
The Toomre Q parameter values are found to be large (>> 1) mainly due to the
low disc surface density and the high rotation velocity resulting due to the
dominant dark matter halo, which could explain the observed low star formation
rate. For the stars-alone case, the disc shows finite swing amplification but
the addition of dark matter halo suppresses that amplification almost
completely. Even the inclusion of the low-dispersion gas which constitutes a
high disc mass fraction does not help in causing swing amplification. This can
explain why these galaxies do not show strong spiral features. Thus the
dynamical effect of a halo that is dominant from inner regions can naturally
explain why star formation and spiral features are largely suppressed in low
surface brightness galaxies, making these different from the high surface
brightness galaxies.


title: Asssociative algebras under multi-commutator

abstract:
  For an associative algebra $A$ a skew-symmetric sum of $n!$ products of $n$
elements of $A$ in all possible order is called $n$-commutator. We consider $A$
as $n$-ary algebra under $n$-commutator. We prove that it has an identity of
$\omega$-degree $2$ (namely, homotopical $n$-Lie identity) if $n$ is even and
an identity of $\omega$-degree $3$ if $n$ is odd.


title:
Discovery of H-alpha Emission from the Close Companion Inside the Gap of
  Transitional Disk HD142527

abstract:
  We utilized the new high-order 585 actuator Magellan Adaptive Optics system
(MagAO) to obtain very high-resolution visible light images of HD142527 with
MagAO's VisAO science camera. In the median seeing conditions of the 6.5m
Magellan telescope (0.5-0.7"), we find MagAO delivers 24-19% Strehl at H-alpha
(0.656 microns). We detect a faint companion (HD142527B) embedded in this young
transitional disk system at just 86.3+/-1.9 mas (~12 AU) from the star. The
companion is detected in both H-alpha and a continuum filter
(Delta_mag=6.33+/-0.20 mag at H-alpha and 7.50+/-0.25 mag in the continuum
filter). This provides confirmation of the tentative companion discovered by
Biller and co-workers with sparse aperture masking at the 8m VLT. The H-alpha
emission from the ~0.25 solar mass companion (EW=180 Angstroms) implies a mass
accretion rate of ~5.9x10^-10 Msun/yr, and a total accretion luminosity of 1.2%
Lsun. Assuming a similar accretion rate, we estimate that a 1 Jupiter mass gas
giant could have considerably better (50-1,000x) planet/star contrasts at
H-alpha than at H band (COND models) for a range of optical extinctions (3.4-0
mag). We suggest that ~0.5-5 Mjup extrasolar planets in their gas accretion
phase could be much more luminous at H-alpha than in the NIR. This is the
motivation for our new MagAO GAPplanetS survey for extrasolar planets.


title: Quantifying Information Flow During Emergencies

abstract:
  Recent advances on human dynamics have focused on the normal patterns of
human activities, with the quantitative understanding of human behavior under
extreme events remaining a crucial missing chapter. This has a wide array of
potential applications, ranging from emergency response and detection to
traffic control and management. Previous studies have shown that human
communications are both temporally and spatially localized following the onset
of emergencies, indicating that social propagation is a primary means to
propagate situational awareness. We study real anomalous events using
country-wide mobile phone data, finding that information flow during
emergencies is dominated by repeated communications. We further demonstrate
that the observed communication patterns cannot be explained by inherent
reciprocity in social networks, and are universal across different
demographics.


title: Particle current fluctuations in a variant of asymmetric Glauber model

abstract:
  We study the total particle current fluctuations in a one-dimensional
stochastic system of classical particles consisting of branching and death
processes which is a variant of asymmetric zero-temperature Glauber dynamics.
The full spectrum of a modified Hamiltonian, whose minimum eigenvalue generates
the large deviation function for the total particle current fluctuations
through a Legendre-Fenchel transformation, is obtained analytically. Three
examples are presented and numerically exact results are compared to our
analytical calculations.


title:
Topologically protected photonic transport in bi-anisotropic
  meta-waveguides

abstract:
  We propose a design of two-dimensional bi-anisotropic meta-waveguide
exhibiting topologically nontrivial photonic phase and robust photonic
transport. The structure proposed represents a waveguide formed by a periodic
array of metallic cylinders placed inside parallel metal plates and is designed
to support two pairs of Dirac cones thus allowing emulation of the spin of the
electrons in condensed matter systems. It is shown, that by making the
meta-waveguide bi-anisotropic one can mimic the spin-orbital interaction in
topological insulators and open a complete photonic topological band gap.
First-principle numerical simulations demonstrate that the domain walls between
two meta-waveguides with reversed bi-anisotropy support photonic edge states
robust against certain classes of structural imperfections, including sharp
bends and disorder.


title:
Exotic Quarkonium Spectroscopy: X(3872), Z_b(10610), and Z_b(10650) in
  Non-Relativistic Effective Theory

abstract:
  This talk summarizes recent developments in quarkonium spectroscopy. I
comment on the relation between the Z_b(10610) and Z_b(10650) and recently
observed Z_c(3900) and Z_c(4025) states. Then I discuss a number of
calculations using non-relativistic effective field theory for the X(3872),
Z_b(10610), and Z_b(10650), under the assumption that these are shallow
molecular bound states of charm or bottom mesons.


title: A quantum-walk-inspired adiabatic algorithm for graph isomorphism

abstract:
  We present a 2-local quantum algorithm for graph isomorphism GI based on an
adiabatic protocol. By exploiting continuous-time quantum-walks, we are able to
avoid a mere diffusion over all possible configurations and to significantly
reduce the dimensionality of the visited space. Within this restricted space,
the graph isomorphism problem can be translated into the search of a satisfying
assignment to a 2-SAT formula without resorting to perturbation gadgets or
projective techniques. We present an analysis of the execution time of the
algorithm on small instances of the graph isomorphism problem and discuss the
issue of an implementation of the proposed adiabatic scheme on current quantum
computing hardware.


title:
Local magnetoresistance in Fe/MgO/Si lateral spin valve at room
  temperature

abstract:
  Room temperature local magnetoresistance in two-terminal scheme is reported.
By employing 1.6 nm-thick MgO tunnel barrier, spin injection efficiency is
increased, resulting in large non-local magnetoresistance. The magnitude of the
non-local magnetoresistance is estimated to be 0.0057 ohm at room temperature.
As a result, a clear rectangle signal is observed in local magnetoresistance
measurement even at room temperature. We also investigate the origin of local
magnetoresistance by measuring the spin accumulation voltage of each contact
separately.


title: Vector inflation by kinetic coupled gravity

abstract:
  Vector inflation is a newly established model where inflation is driven by
non-minimally coupled massive vector fields with a potential term. This model
is similar to the model of chaotic inflation with scalar fields, except that
for vector fields the isotropy of expansion is achieved either by considering a
triplet of orthogonal vector fields or $N$ randomly oriented independent vector
fields. We introduce a new version of vector inflation where the vector field
has no potential term but is non-minimally coupled to gravity through the
kinetic term. The non-minimal coupling is established by introducing the
Einstein tensor besides the metric tensor within the kinetic term of the vector
field.


title: Anomalous magnetism of Pr in PrCoAsO

abstract:
  Detailed magnetization and magneto-transport measurements studies are carried
out to unearth the anomalous magnetism of Pr in PrCoAsO compound. The studied
PrCoAsO sample is single phase and crystallized in the tetragonal structure
with space group P4/nmm in analogy of ZrCuSiAs type compounds. Detailed
magnetization measurements showed that Co moments in PrCoAsO exhibit weakly
itinerant ferromagnetic Co spins ordering at below 80 K with a small magnetic
moments of 0.12 muB/f.u. High temperatures Curie-Weiss fit, resulted in
effective paramagnetic moment mueff (exp) of 5.91 muB/f.u., which can be
theoretically assigned to 3d Co (3.88 muB) and 4f Pr (3.58 muB). Further, a
positive Curie- Weiss temperature of 136 K is seen, indicating predominant
ferromagnetic interactions in PrCoAsO. Detailed transport measurements showed
that PrCoAsO exhibit metallic behavior and negative magneto-resistance below
ferro-magnetically (FM) ordered state. Surprisingly, the situation of PrCoAsO
is similar to non magnetic La containing LaCoAsO and strikingly different than
that as reported for magnetic Nd, Sm and Gd i.e., (Nd/Sm/Gd)CoAsO. The magnetic
behavior of PrCoAsO being closed to LaCoAsO and strikingly different to that of
(Nd/Sm/Gd)CoAsO is unusual.


title:
Testing the nature of the supermassive black hole candidate in SgrA*
  with light curves and images of hot spots

abstract:
  General relativity makes clear predictions about the spacetime geometry
around black holes. In the near future, new facilities will have the capability
to explore the metric around SgrA$^*$, the supermassive black hole candidate at
the Center of our Galaxy, and open a new window to test the Kerr black hole
hypothesis. In this paper, we compute light curves and images associated with
compact emission regions (hot spots) orbiting around Kerr and non-Kerr black
holes. We study how the analysis of the properties of the radiation emitted by
a hot spot can be used to test the Kerr nature of SgrA$^*$. We find that the
sole observation of the hot spot light curve can at most constrain a
combination of the black hole spin and of possible deviations from the Kerr
solution. This happens because the same orbital frequency around a Kerr black
hole can be found for a non-Kerr object with a different spin parameter. Second
order corrections in the light curve due to the background geometry are
typically too small to be identified. While the observation of the hot spot
centroid track can potentially bound possible deviations from the Kerr
solution, that is out of reach for the near future VLTI instrument GRAVITY. The
Kerr black hole hypothesis could really be tested in the case of the discovery
of a radio pulsar in a compact orbit around SgrA$^*$. Radio observations of
such a pulsar would provide precise estimates of the mass and the spin of
SgrA$^*$, and the combination of these measurements (probing the weak field)
with the hot spot light curve information (probing the strong field) may
constrain/find possible deviations from the Kerr solution with quite good
precision.


title: Classification of log del Pezzo surfaces of index three

abstract:
  A normal projective non-Gorenstein log-terminal surface $S$ is called a log
del Pezzo surface of index three if the three-times of the anti-canonical
divisor $-3K_S$ is an ample Cartier divisor. We classify all of the log del
Pezzo surfaces of index three. The technique for the classification based on
the argument of Nakayama.


title: Production of Stoponium at the LHC

abstract:
  Although the Large Hadron Collider (LHC) has not observed supersymmetric
(SUSY) partners of the Standard Model particles, their existence is not ruled
out yet. One recently explored scenario in which there are light SUSY partners
that have evaded current bounds from the LHC is that of a light long-lived stop
quark. In this paper we consider light stop pair production at the LHC when the
stop mass is between 200 and 400 GeV. If the stops are long-lived they can form
a bound state, stoponium, which then undergoes two-body decays to Standard
Model particles. By considering the near-threshold production of such a pair
through the gluon-gluon fusion process and taking into account the strong
Coulombic interactions responsible for the formation of this bound state, we
obtain factorization theorems for the stop pair inclusive and differential
production cross sections. We also perform a resummation of large threshold
logarithms up to next-to-next-to-leading logarithmic accuracy using
well-established renormalization group equations in an effective field theory
methodology. These results are used to calculate the invariant mass
distributions of two photons or two Z bosons coming from the decay of the
stoponium at the LHC. For our choices of SUSY model parameters, the stoponium
is not detectable above Standard Model backgrounds in \gamma \gamma or ZZ at 8
TeV, but will be visible with 400 fb^(-1) of accumulated data if its mass is
below 500 GeV when the LHC runs at 14 TeV.


title: Principal Solutions Revisited

abstract:
  The main objective of this paper is to identify principal solutions
associated with Sturm-Liouville operators on arbitrary open intervals $(a,b)
\subseteq \mathbb{R}$, as introduced by Leighton and Morse in the scalar
context in 1936 and by Hartman in the matrix-valued situation in 1957, with
Weyl-Titchmarsh solutions, as long as the underlying Sturm-Liouville
differential expression is nonoscillatory (resp., disconjugate or bounded from
below near an endpoint) and in the limit point case at the endpoint in
question. In addition, we derive an explicit formula for Weyl-Titchmarsh
functions in this case (the latter appears to be new in the matrix-valued
context).


title:
Cosmological constraints on interacting dark energy with redshift-space
  distortion after Planck data

abstract:
  The interacting dark energy model could propose a effective way to avoid the
coincidence problem. In this paper, dark energy is taken as a fluid with a
constant equation of state parameter $w_x$. In a general gauge, we could obtain
two sets of different perturbation equations when the momentum transfer
potential is vanished in the rest frame of dark matter or dark energy. There
are many kinds of interacting forms from the phenomenological considerations,
here, we choose $Q=3H\xi_x\rho_x$ which owns the stable perturbations in most
cases. Then, according to the Markov Chain Monte Carlo method, we constrain the
model by currently available cosmic observations which include cosmic microwave
background radiation, baryon acoustic oscillation, type Ia supernovae, and
$f\sigma_8(z)$ data points from redshift-space distortion. Jointing the
geometry tests with the large scale structure information, the results show a
tighter constraint on the interacting model than the case without
$f\sigma_8(z)$ data. We find the interaction rate in 3$\sigma$ regions:
$\xi_x=0.00372_{-0.00372- 0.00372-0.00372}^{+0.000768+0.00655+0.0102}$. It
means that the recently cosmic observations favor a small interaction rate
between the dark sectors, at the same time, the measurement of redshift-space
distortion could rule out a large interaction rate in the 1$\sigma$ region.


title:
The chart based approach to studying the global structure of a spacetime
  induces a coordinate invariant boundary

abstract:
  I demonstrate that the chart based approach to the study of the global
structure of Lorentzian manifolds induces a homeomorphism of the manifold into
a topological space as an open dense set. The topological boundary of this
homeomorphism is a chart independent boundary of ideal points equipped with a
topological structure and a physically motivated classification. I show that
this new boundary contains all other boundaries that can be presented as the
topological boundary of an envelopment. Hence, in particular, it is a
generalisation of Penrose's conformal boundary. I provide three detailed
examples: the conformal compactification of Minkowski spacetime, Scott and
Szekeres' analysis of the Curzon singularity and Beyer and Hennig's analysis of
smooth Gowdy symmetric generalised Taub-NUT spacetimes.


title:
Accelerating the Averaging Rate of Atomic Ensemble Clock Stability using
  Atomic Phase Lock

abstract:
  We experimentally demonstrated that the stability of an atomic clock improves
at fastest rate $\tau^{-1}$ (where $\tau$ is the averaging time) when the phase
of a local oscillator is genuinely compared to the continuous phase of many
atoms in a single trap (atomic phase lock). For this demonstration, we
developed a simple method that repeatedly monitors the atomic phase while
retaining its coherence by observing only a portion of the whole ion cloud.
Using this new method, we measured the continuous phase over 3 measurement
cycles, and thereby improved the stability scaling from $\tau^{-1/2}$ to
$\tau^{-1}$ during the 3 measurement cycles.
  %Compared with the standard method that initialize phase during each
measurement cycle, the long term stability was improved by a factor of
$\sqrt{n_{cp}}$ (where $n_{cp}$ is the number of continuous phase
measurements).
  This simple method provides a path by which atomic clocks can approach a
quantum projection noise limit, even when the measurement noise is dominated by
the technical noise.


title: Implementing Software Project Control Centers: An Architectural View

abstract:
  Setting up effective and efficient mechanisms for controlling software and
system development projects is still challenging in industrial practice. On the
one hand, necessary prerequisites such as established development processes,
understanding of cause-effect relationships on relevant indicators, and
sufficient sustainability of measurement programs are often missing. On the
other hand, there are more fundamental methodological deficits related to the
controlling process itself and to appropriate tool support. Additional
activities that would guarantee the usefulness, completeness, and precision of
the result- ing controlling data are widely missing. This article presents a
conceptual architecture for so-called Software Project Control Centers (SPCC)
that addresses these challenges. The architecture includes mechanisms for
getting sufficiently precise and complete data and supporting the information
needs of different stakeholders. In addition, an implementation of this
architecture, the so-called Specula Project Support Environment, is sketched,
and results from evaluating this implementation in industrial settings are
presented.


title: Program Verification of Numerical Computation

abstract:
  These notes outline a formal method for program verification of numerical
computation. It forms the basis of the software package VPC in its initial
phase of development. Much of the style of presentation is in the form of notes
that outline the definitions and rules upon which VPC is based. The initial
motivation of this project was to address some practical issues of computation,
especially of numerically intensive programs that are commonplace in computer
models. The project evolved into a wider area for program construction as
proofs leading to a model of inference in a more general sense. Some basic
results of machine arithmetic are derived as a demonstration of VPC.


title: The dual superconformal surface

abstract:
  It is shown that a superconformal surface with arbitrary codimension in flat
Euclidean space has a (necessarily unique) dual superconformal surface if and
only if the surface is S-Willmore, the latter a well-known necessary condition
to allow a dual as shown by Ma \cite{ma}. Duality means that both surfaces
envelope the same central sphere congruence and are conformal with the induced
metric. Our main result is that the dual surface to a superconformal surface
can easily be described in parametric form in terms of a parametrization of the
latter. Moreover, it is shown that the starting surface is conformally
equivalent, up to stereographic projection in the nonflat case, to a minimal
surface in a space form (hence, S-Willmore) if and only if either the dual
degenerates to a point (flat case) or the two surfaces are conformally
equivalent (nonflat case).


title:
An Empirical Method to Measure Stochasticity and Multifractality in
  Nonlinear Time Series

abstract:
  An empirical algorithm is used here to study the stochastic and multifractal
nature of nonlinear time series. A parameter can be defined to quantitatively
measure the deviation of the time series from a Wiener process so that the
stochasticity of different time series can be compared. The local volatility of
the time series under study can be constructed using this algorithm and the
multifractal structure of the time series can be analyzed by using this local
volatility. As an example, we employ this method to analyze financial time
series from different stock markets. The result shows that while developed
markets evolve very much like an Ito process, the emergent markets are far from
efficient. Differences about the multifractal structures and leverage effects
between developed and emergent markets are discussed. The algorithm used here
can be applied in a similar fashion to study time series of other complex
systems.


title: Special L-values of abelian t-modules

abstract:
  We prove a formula for the $\infty$-adic special $L$-value of abelian
$t$-modules. This gives function field analogues of the class number formula.
We also express it in terms of the extension groups of shtukas.


title:
Analysis and Optimization of Random Sensing Order in Cognitive Radio
  Networks

abstract:
  Developing an efficient spectrum access policy enables cognitive radios to
dramatically increase spectrum utilization while ensuring predetermined quality
of service levels for primary users. In this paper, modeling, performance
analysis, and optimization of a distributed secondary network with random
sensing order policy are studied. Specifically, the secondary users create a
random order of available channels upon primary users return, and then find
optimal transmission and handoff opportunities in a distributed manner. By a
Markov chain analysis, the average throughputs of the secondary users and
average interference level among the secondary and primary users are
investigated. A maximization of the secondary network performance in terms of
the throughput while keeping under control the average interference is
proposed. It is shown that despite of traditional view, non-zero false alarm in
the channel sensing can increase channel utilization, especially in a dense
secondary network where the contention is too high. Then, two simple and
practical adaptive algorithms are established to optimize the network. The
second algorithm follows the variations of the wireless channels in
non-stationary conditions and outperforms even static brute force optimization,
while demanding few computations. The convergence of the distributed algorithms
are theoretically investigated based on the analytical performance indicators
established by the Markov chain analysis. Finally, numerical results validate
the analytical derivations and demonstrate the efficiency of the proposed
schemes. It is concluded that fully distributed sensing order algorithms can
lead to substantial performance improvements in cognitive radio networks
without the need of centralized management or message passing among the users.


title: Transversity Distribution Functions in the Valon Model

abstract:
  By using the valon model, we calculate the Transverse Momentum Distribution
functions, TMDs, inside the Nucleon. TMDs indicate the probability to find
partons with spin aligned (anti- aligned) to the transversely polarized
nucleon. The results are in good agreements with all available experimental
data and also global fits.


title:
Asymptotics of the probability distributions of the first hitting times
  of Bessel processes

abstract:
  The asymptotic behavior of the tail probabilities for the first hitting times
of the Bessel process with arbitrary index is shown without using the explicit
expressions for the distribution function obtained in the authors' previous
works.


title:
Shell interactions for Dirac operators: on the point spectrum and the
  confinement

abstract:
  Spectral properties and the confinement phenomenon for the coupling $H+V$ are
studied, where $H=-i\alpha\cdot\nabla +m\beta$ is the free Dirac operator in
$\mathcal{R}^3$ and $V$ is a measure-valued potential. The potentials $V$ under
consideration are given in terms of surface measures on the boundary of bounded
regular domains in $\mathcal{R}^3$.
  A criterion for the existence of point spectrum is given, with applications
to electrostatic shell potentials. In the case of the sphere, an uncertainty
principle is developed and its relation with some eigenvectors of the coupling
is shown.
  Furthermore, a criterion for generating confinement is given. As an
application, some known results about confinement on the sphere for
electrostatic plus Lorentz scalar shell potentials are generalized to regular
surfaces.


title:
The study of the nonleptonic two body B decays involving a light tensor
  meson in final states

abstract:
  The nonleptonic two body $B_{u,d,s,c}$ decays involving a light tensor meson
in final states are studied in the perturbative QCD approach based on $k_T$
factorization. The decay modes with a tensor meson emitted, are prohibited in
naive factorization, since the emission diagram with a tensor meson produced
from vacuum is vanished. While contributions from the so-called hard scattering
emission diagrams and annihilation type diagrams are important and calculable
in the perturbative QCD approach.
  The branching rations of most decays are in the range of $10^{-4}$ to
$10^{-8}$, which are bigger by 1 or 2 orders of magnitude than the predictions
given by naive factorization, but consistent with the predictions from QCD
factorization and the recent experimental measurements. We also give the
predictions for the direct $CP$ asymmetries, some of which are large enough for
the future experiments to measure. We also find that, even with a small mixing
angle, the mixing between $f_2$ and $f_2^{\prime}$ can bring remarkable changes
to both branching ratios and the direct $CP$ asymmetries for some decays
involving $f_2^{(\prime)}$ mesons.
  For decays with a vector meson and a tensor meson in final states, we predict
a large percentage of transverse polarization contributions due to the
contributions of the orbital angular momentum of the tensor mesons.


title:
Wavelength Spacing Tunable, Multiwavelength Q-Switched Mode-Locked Laser
  Based on Graphene-Oxide-Deposited Tapered Fiber

abstract:
  A wavelength spacing tunable, multiwavelength Q-switched mode-locked (QML)
fiber laser in an erbium-doped fiber cavity based on graphene oxide deposited
on tapered fiber is proposed by choosing the diameter and length of the taper,
graphene oxide thickness and cavity dispersion, in which the wavelength spacing
could be tuned by pump power. The evolutions of temporal and spectral with
different pump strengths are investigated. Results show that the tunability of
the multiwavelength laser can be interpreted by the bound states of QML laser
resulting from a mutual interaction of dispersion, nonlinear effect, insertion
loss, and pump power. To the best of our knowledge, it is the first
experimental observation of bound states of QML, which provides a new mechanism
to fabricate tunable multiwavelength laser.


title: An Affirmative Answer to a Core Issue on Limit Operators

abstract:
  An operator on an $l^{p}$-space is called band-dominated if it can be
approximated, in the operator norm, by operators with a banded matrix
representation. It is known that a rich band-dominated operator is
$\mathcal{P}$-Fredholm (which is a generalization of the classical Fredholm
property) if and only if all of its so-called limit operators are invertible
and their inverses are uniformly bounded. We show that the condition on uniform
boundedness is redundant in this statement.


title:
Covariance pattern mixture models for the analysis of multivariate
  heterogeneous longitudinal data

abstract:
  We propose a novel approach for modeling multivariate longitudinal data in
the presence of unobserved heterogeneity for the analysis of the Health and
Retirement Study (HRS) data. Our proposal can be cast within the framework of
linear mixed models with discrete individual random intercepts; however,
differently from the standard formulation, the proposed Covariance Pattern
Mixture Model (CPMM) does not require the usual local independence assumption.
The model is thus able to simultaneously model the heterogeneity, the
association among the responses and the temporal dependence structure. We focus
on the investigation of temporal patterns related to the cognitive functioning
in retired American respondents. In particular, we aim to understand whether it
can be affected by some individual socio-economical characteristics and whether
it is possible to identify some homogenous groups of respondents that share a
similar cognitive profile. An accurate description of the detected groups
allows government policy interventions to be opportunely addressed. Results
identify three homogenous clusters of individuals with specific cognitive
functioning, consistent with the class conditional distribution of the
covariates. The flexibility of CPMM allows for a different contribution of each
regressor on the responses according to group membership. In so doing, the
identified groups receive a global and accurate phenomenological
characterization.


title: Optimization in Knowledge-Intensive Crowdsourcing

abstract:
  We present SmartCrowd, a framework for optimizing collaborative
knowledge-intensive crowdsourcing. SmartCrowd distinguishes itself by
accounting for human factors in the process of assigning tasks to workers.
Human factors designate workers' expertise in different skills, their expected
minimum wage, and their availability. In SmartCrowd, we formulate task
assignment as an optimization problem, and rely on pre-indexing workers and
maintaining the indexes adaptively, in such a way that the task assignment
process gets optimized both qualitatively, and computation time-wise. We
present rigorous theoretical analyses of the optimization problem and propose
optimal and approximation algorithms. We finally perform extensive performance
and quality experiments using real and synthetic data to demonstrate that
adaptive indexing in SmartCrowd is necessary to achieve efficient high quality
task assignment.


title: Primitive Monodromy Groups of Genus at most Two

abstract:
  We show that if the action of a classical group $G$ on a set $\Omega$ of
$1$-spaces of its natural module is of genus at most two, then $|\Omega| \leq
10,000$.


title:
Quantum critical dynamics of the boson system in the Ginsburg-Landau
  model

abstract:
  The quantum critical dynamics of the quantum phase transitions is considered.
In the framework of the unified theory, based on the Keldysh technique, we
consider the crossover from the classical to the quantum description of the
boson many-particle system dynamics close to the second order quantum phase
transition. It is shown that in this case the upper critical space dimension of
this model is $d_c^{+}=2$, therefore the quantum critical dynamics approach is
useful in case of $d<2$. In the one-dimension system the phase coherence time
does diverge at the quantum critical point, $g_c$, and has the form of $\tau
\propto -\ln |g-g_c|/(g-g_c) $, the correlation radius diverges as $r_c\propto
|g-g_c|^{-\nu} (\nu = 0.6)$.


title:
Delivering 10 Gb/s optical data with picosecond timing uncertainty over
  75 km distance

abstract:
  We report a method to determine propagation delays of optical 10 Gb/s data
traveling through a 75 km long amplified fiber link with an uncertainty of 4
ps. The one-way propagation delay is determined by two-way exchange and cross
correlation of short (< 1 ms) bursts of 10 Gb/s data, with a single-shot time
resolution better than 2.5 ps. We thus achieve a novel optical communications
link suited for both long-haul high-capacity data transfer and time transfer
with picosecond-range uncertainty. This opens up the perspective of
synchronized optical telecommunication networks allowing picosecond-range time
distribution and millimeter-range positioning.


title:
Gravity-driven enhancement of heavy particle clustering in turbulent
  flow

abstract:
  Heavy particles suspended in a turbulent flow settle faster than in a still
fluid. This effect stems from a preferential sampling of the regions where the
fluid flows downward and is quantified here as a function of the level of
turbulence, of particle inertia, and of the ratio between gravity and turbulent
accelerations. By using analytical methods and detailed, state-of-the-art
numerical simulations, settling is shown to induce an effective horizontal
two-dimensional dynamics that increases clustering and reduce relative
velocities between particles. These two competing effects can either increase
or decrease the geometrical collision rates between same-size particles and are
crucial for realistic modeling of coalescing particles.


title: 1-bit Compressive Data Gathering for Wireless Sensor Networks

abstract:
  Compressive sensing (CS) has been widely used for the data gathering in
wireless sensor networks for the purpose of reducing the communication overhead
recent years. In this paper, we first show that with simple modification, 1-bit
compressive sensing can also been used for the data gathering in wireless
sensor networks to further reduce the communication overhead. We also propose a
novel blind 1-bit CS reconstruction algorithm which outperforms other state of
the art blind 1-bit CS reconstruction algorithms. Experimental results on real
sensor datasets demonstrate the efficiency of our method.


title: Dynamic Assignment in Microsimulations of Pedestrians

abstract:
  A generic method for dynamic assignment used with microsimulation of
pedestrian dynamics is introduced. As pedestrians - unlike vehicles - do not
move on a network, but on areas they in principle can choose among an infinite
number of routes. To apply assignment algorithms one has to select for each OD
pair a finite (realistically a small) number of relevant representatives from
these routes. This geometric task is the main focus of this contribution. The
main task is to find for an OD pair the relevant routes to be used with common
assignment methods. The method is demonstrated for one single OD pair and
exemplified with an example.


title:
Surface Impedance and Bulk Band Geometric Phases in One-Dimensional
  Systems

abstract:
  Surface impedance is an important concept in classical wave systems such as
photonic crystals (PCs). For example, the condition of an interface state
formation in the interfacial region of two different one-dimensional PCs is
simply Z_SL +Z_SR=0, where Z_SL (Z_SR)is the surface impedance of the
semi-infinite PC on the left- (right-) hand side of the interface. Here, we
also show a rigorous relation between the surface impedance of a
one-dimensional PC and its bulk properties through the geometrical (Zak) phases
of the bulk bands, which can be used to determine the existence or
non-existence of interface states at the interface of the two PCs in a
particular band gap. Our results hold for any PCs with inversion symmetry,
independent of the frequency of the gap and the symmetry point where the gap
lies in the Brillouin Zone. Our results provide new insights on the
relationship between surface scattering properties, the bulk band properties
and the formation of interface states, which in turn can enable the design of
systems with interface states in a rational manner.


title: Bond order potential for FeSi

abstract:
  A new parameter set has been derived for FeSi using the Albe-Erhart-type bond
order potential (BOP) and the PONTIFIX code for fitting the parameters on a
large training set of various polymorphs. Ab initio calculations are also
carried out to study the relative stability of various polymorphs and to use
the obtained data in the training set. The original BOP formalism was unable to
account for the correct energetic relationship between the B20
($\epsilon$-FeSi) and B2 (CsCl) phases and notoriusly slightly favors
incorrectly the B2 polymorph. In order to correct this improper behavior the
BOP potential has been extended by a Columbic term (BOP+C) in order to account
for the partial ionic character of FeSi. Using this potential we are able to
account for the correct phase order between the most stable B20 and B2 (CsCl)
polymorphs when the net atomic charges are properly set. Although this brings
in a new somewhat uncertain parameter (the net charges) one can adjust properly
the BOP+C potential for specific problems. To demonstrate this we study under
high pressure the B2 phase which becomes more stable vs. B20 as it is found
experimentally and expected to be taken place in the Earth mantle. The obtained
BOP has also been tested for the metallic and semiconducting disilicides
($\alpha$-FeSi$_2$ and $\beta$-FeSi$_2$) and for the Si/$\beta$-FeSi$_2$
heterostructure. The obtained BOP, as many other BOP, overestimates the melting
point ($T_m$) of the B20 phase by $\sim 1000$ K if the parameters in the radial
part of the potential were obtained according to the Pauling relation (regular
way).


title: Global aspects of double geometry

abstract:
  We consider the concept of a generalised manifold in the O(d,d) setting,
i.e., in double geometry. The conjecture by Hohm and Zwiebach for the form of
finite generalised diffeomorphisms is shown to hold. Transition functions on
overlaps are defined. Triple overlaps are trivial concerning their action on
coordinates, but non-trivial on fields, including the generalised metric. A
generalised manifold is an ordinary manifold, but the generalised metric on the
manifold carries a gerbe structure. We show how the abelian behaviour of the
gerbe is embedded in the non-abelian T-duality group. We also comment on
possibilities and difficulties in the U-duality setting.


title: The radio morphology of a spatially resolved SSC model

abstract:
  One of the main, unresolved questions about the nature of quasars is the
position of the acceleration site responsible for the highest energies. The
attempt to investigate this question in the energy regime with the highest
resolution, the radio band, has the downside that no theoretical model exists
that can connect these two regimes. The model in this work tries to shrink this
gap by extending the general synchrotron self Compton (SSC) model up to length
scales in the order of the resolution of radio observations. The resulting
spectral energy distributions (SED) show a qualitative improvement in the
representation of the radio spectrum. Furthermore the obtained emission
morphology shows similar properties to the radio structures observed in jets of
quasars. A complete and quantitative connection will however need either much
higher numerical effort or an improved methodology.


title: Proving Abstractions of Dynamical Systems through Numerical Simulations

abstract:
  A key question that arises in rigorous analysis of cyberphysical systems
under attack involves establishing whether or not the attacked system deviates
significantly from the ideal allowed behavior. This is the problem of deciding
whether or not the ideal system is an abstraction of the attacked system. A
quantitative variation of this question can capture how much the attacked
system deviates from the ideal. Thus, algorithms for deciding abstraction
relations can help measure the effect of attacks on cyberphysical systems and
to develop attack detection strategies. In this paper, we present a decision
procedure for proving that one nonlinear dynamical system is a quantitative
abstraction of another. Directly computing the reach sets of these nonlinear
systems are undecidable in general and reach set over-approximations do not
give a direct way for proving abstraction. Our procedure uses (possibly
inaccurate) numerical simulations and a model annotation to compute tight
approximations of the observable behaviors of the system and then uses these
approximations to decide on abstraction. We show that the procedure is sound
and that it is guaranteed to terminate under reasonable robustness assumptions.


title:
Nonsteady dynamic properties of a domain wall for the creep state under
  an alternating driving field

abstract:
  With Monte Carlo simulations, the nonsteady dynamics properties of a domain
wall have been systematically investigated for the thermally activated creep
state under an alternating driving field. Taking the driven random-field Ising
model in two dimensions as an example, two distinct growth stages of the domain
interface are identified with both the correlation length and roughness
function. One stage belongs to the universality class of the random
depositions, and the other to that of the quenched Edwards-Wilkinson equation.
In the latter case, due to the dynamic effect of overhangs, the domain
interface may exhibit an intrinsic anomalous scaling behavior, different from
that of the quenched Edwards-Wilkinson equation.


title:
Emergent spatial structures in flocking models: a dynamical system
  insight

abstract:
  We show that hydrodynamic theories of polar active matter generically possess
inhomogeneous traveling solutions. We introduce a unifying dynamical-system
framework to establish the shape of these intrinsically nonlinear patterns, and
show that they correspond to those hitherto observed in experiments and
numerical simulations: periodic density waves, and solitonic bands, or
polar-liquid droplets both cruising in isotropic phases. We elucidate their
respective multiplicity and mutual relations, as well as their existence
domain.


title: Solar analogues and Solar twins in the HARPS archive

abstract:
  We present 63 Solar analogues and twins for which high S/N archival data are
available for the HARPS high resolution spectrograph at the ESO 3.6m telescope.
We perform a differential analysis of these stellar spectra relative to the
Solar spectrum, similar to previous work using ESO 2.2m/FEROS data, and expand
our analysis by introducing a new method to test the temperature and
metallicity calibration of Sun-like stars in the Geneva-Copenhagen-Survey
(GCS). The HARPS data are significantly better than the FEROS data, with
improvements in S/N, spectral resolution, and number of lines we can analyse.
We confirm the offsets to the photometric scale found in our FEROS study. We
confirm 3 Solar twins found in the FEROS data as Solar twins in the HARPS data,
as well as identify 6 new twins.


title: Magnetic fields and halos in spiral galaxies

abstract:
  Radio continuum observations allow to reveal the magnetic field structure in
the disk and halo of nearby spiral galaxies, their magnetic field strength and
vertical scale heights. The spiral galaxies studied so far show a similar
magnetic field pattern which is of spiral shape along the disk plane and
X-shaped in the halo, sometimes accompanied by strong vertical fields above and
below the central region of the disk. The strength of the halo field is
comparable to that of the disk. The total and turbulent magnetic field strength
is (weakly) increasing with the star formation. There are, however, indications
that stronger star formation reduces the magnetic field regularity globally.
The magnetic field in spiral galaxies is generally thought to be amplified and
maintained by dynamo action. During the galaxy's formation and evolution the
turbulent dynamo amplifies the field strength to energy equipartition with the
turbulent gas, while the large-scale (mean-field) dynamo mainly orders the
magnetic field. Hence, the large-scale magnetic field pattern evolves with
time. Supernova explosions causes a further continuous injection of turbulent
magnetic fields. Assuming that this small-scale field injection is situated
only within the spiral arm region where star formation mostly occurs lead to a
large-scale field structure in which the magnetic field regularity is stronger
in the interarm region as observed in several nearby spiral galaxies. The
detection of similar scale heights in several spiral galaxies of different
Hubble type star formation implies a relation between the galactic wind, the
total magnetic field strength and the star formation in the galaxy. A galactic
wind may be essential for an effective dynamo action. Strong tidal interaction,
however, seems to disturb the balance leading to deviating and locally
different scale heights as observed in M82 and NGC~4631.


title: A Robust Biometric-Based Three-factor Remote User Authentication Scheme

abstract:
  The rapid development of Internet of Things (IoT) technology, which is an
inter connection of networks through an insecure public channel i.e. Internet
demands for authenticating the remote user trying to access the secure network
resources. In 2013, Ankita et al. proposed an improved three factor remote user
authentication scheme. In this poster we will show that Ankita et al scheme is
vulnerable to known session specific temporary information attack, on
successfully performing the attack, the adversary can perform all other major
cryptographic attacks. As a part of our contribution, we will propose an
improved scheme which is resistance to all major cryptographic attacks and
overcomes the defects in Ankita et al. scheme.


title: Self-consistent description of single-particle levels of magic nuclei

abstract:
  Single-particle levels of seven magic nuclei are calculated within the Energy
Density Functional (EDF) method by Fayans et al. Three versions of the EDF are
used, the initial Fayans functional DF3 and its two variations, DF3-a and
DF3-b, with different values of spin-orbit parameters. Comparison is made with
predictions of the Skyrme-Hartree-Fock method with the HFB-17 functional. For
the DF3-a functional, phonon coupling (PC) corrections to single-particle
energies are found self-consistently with an approximate account for the
tadpole diagram. Account for the PC corrections improves agreement with the
data for heavy nuclei, e.g. for 208 Pb. On the other hand, for lighter nuclei,
e.g. 40,48 Ca, PC corrections make the agreement a little worse. As estimations
show, the main reason is that the approximation we use for the tadpole term is
less accurate for the light nuclei.


title: A Functional Model for SMP Matrices and the Jacobi Flow

abstract:
  This is the second part of the paper arXiv:1309.0959v2 on the theory of SMP
(Strong Moment Problem) matrices and their relation to the Killip-Simon problem
on two disjoint intervals. In this part we define and study the Jacobi flow on
SMP matrices.


title:
Utility Rate Equations of Group Population Dynamics in Biological and
  Social Systems

abstract:
  We present a novel system of equations to describe the evolution of
self-organized structured societies (biological or human) composed of several
trait groups. The suggested approach is based on the combination of ideas
employed in the theory of biological populations, system theory, and utility
theory. The evolution equations are defined as utility rate equations, whose
parameters are characterized by the utility of each group with respect to the
society as a whole and by the mutual utilities of groups with respect to each
other. We analyze in detail the cases of two groups (cooperators and defectors)
and of three groups (cooperators, defectors, and regulators) and find that, in
a self-organized society, neither defectors nor regulators can overpass the
maximal fractions of about 10% each. This is in agreement with the data for bee
and ant colonies. The classification of societies by their distance from
equilibrium is proposed. We apply the formalism to rank the countries according
to the introduced metric quantifying their relative stability, which depends on
the cost of defectors and regulators as well as their respective population
fractions. We find a remarkable concordance with more standard economic ranking
based, for instance, on GDP per capita.