title:
Emergence of nanoscale inhomogeneity in the superconducting state of a
  homogeneously disordered conventional superconductor, NbN

abstract:
  The notion of spontaneous formation of an inhomogeneous superconducting state
is at the heart of most theories attempting to understand the superconducting
state in the presence of strong disorder. Using scanning tunneling spectroscopy
and high resolution scanning transmission electron microscopy, we
experimentally demonstrate that under the competing effects of strong
homogeneous disorder and superconducting correlations, the superconducting
state of a conventional superconductor, NbN, spontaneously segregates into
domains. Tracking these domains as a function of temperature we observe that
the superconducting domains persist across the bulk superconducting transition,
Tc, and disappear close to the pseudogap temperature, T*, where signatures of
superconducting correlations disappear from the tunneling spectrum and the
superfluid response of the system.


title: Opacity of Memory Management in Software Transactional Memory

abstract:
  Opacity of Transactional Memory is proposed to be established by incremental
validation. Quiescence in terms of epoch-based memory reclamation is applied to
deal with doomed transactions causing memory access violations. This method
unfortunately involves increased memory consumption and does not cover
reclamations outside of transactions. This paper introduces a different method
which combines incremental validation with elements of sandboxing to solve
these issues.


title: Towards experimental tests and applications of Lieb-Robinson bounds

abstract:
  Spin-polarized scanning tunneling microscopy is identified as a suitable
experimental technique to investigate the quantitative quality of Lieb-Robinson
bounds on the signal velocity. The latest, most general bound is simplified and
it is shown that there is a discrepancy by a factor of approximately 4 between
the corresponding limit speed and some estimated exact velocities in atomic
spin chains. The observed discrepancy facilitates conclusions for a further
mathematical improvement of Lieb-Robinson bounds. The real signal propagation
can be modified with several experimental parameters from which the bounds are
independent. This enables the application of Lieb-Robinson bounds as upper
limits on the enhancement of the real signal speed for information transport in
spintronic devices.


title: Explicit Flock Solutions for Quasi-Morse potentials

abstract:
  We consider interacting particle systems and their mean-field limits, which
are frequently used to model collective aggregation and are known to
demonstrate a rich variety of pattern formations. The interaction is based on a
pairwise potential combining short-range repulsion and long-range attraction.
We study particular solutions, that are referred to as flocks in the
second-order models, for the specific choice of the Quasi-Morse interaction
potential. Our main result is a rigorous analysis of continuous, compactly
supported flock profiles for the biologically relevant parameter regime.
Existence and uniqueness is proven for three space dimension, whilst existence
is shown for the two-dimensional case. Furthermore, we numerically investigate
additional Morse-like interactions to complete the understanding of this class
of potentials.


title: On the computation of Casimir stresses in open media and Lifshitz theory

abstract:
  A classification of the electromagnetic modes on open and closed spatial
domains containing media with piecewise homogeneous permittivities is used to
facilitate the derivation of quantum induced Casimir stresses in dielectrics.
By directly exploiting the complex analytic properties of solutions of the
macroscopic Maxwell equations for open systems it is shown how regular
expressions for such stresses can be expressed in terms of double integrals
involving either real or pure imaginary frequencies associated with harmonic
modes in conformity with the Lifshitz theory for separated planar dielectric
half-spaces. The derivation is self-contained without recourse to the Krein
formula for a density of states or mode regularization and offers a more direct
approach to other open systems.


title:
Geometric approach to string analysis: deviation from linearity and its
  use for biosequence classification

abstract:
  Tools that effectively analyze and compare sequences are of great importance
in various areas of applied computational research, especially in the framework
of molecular biology. In the present paper, we introduce simple geometric
criteria based on the notion of string linearity and use them to compare DNA
sequences of various organisms, as well as to distinguish them from random
sequences. Our experiments reveal a significant difference between biosequences
and random sequences - the former having much higher deviation from linearity
than the latter - as well as a general trend of increasing deviation from
linearity between primitive and biologically complex organisms.


title:
Electron-Hole Pair Generation in SiC High-Temperature Alpha Particle
  Detectors

abstract:
  We demonstrate alpha-particle detection in an n-type 4H-SiC Schottky diode
detector up to an unprecedented temperature of 500 {\deg}C using an Am-241 disc
source. The measured spectra were used to calculate the electron-hole pair
creation energy in 4H-SiC and its non-bandgap contribution, which are both
found to decrease with increasing temperature. The full width at half maximum
(FWHM) of the measured alpha-energy peaks was found to increase exponentially
with temperature due to an exponential increase of leakage current. For our
measurement system, above 300 {\deg}C, where the leakage current was 10-6 A,
this increase exceeded the FWHM at room temperature.


title: Finite temperature correlations in the Lieb-Liniger 1D Bose gas

abstract:
  We address the problem of calculating finite-temperature response functions
of an experimentally relevant low-dimensional strongly-correlated system: the
integrable 1D Bose gas with repulsive \delta-function interaction (Lieb-Liniger
model). Focusing on the observable dynamical density-density function, we
present a Bethe Ansatz-based method allowing for its accurate evaluation over a
broad range of momenta, frequencies, temperatures and interaction parameters,
in finite but large systems. We show how thermal fluctuations smoothen the zero
temperature critical behavior and present explicit quantitative results in
experimentally accessible regimes.


title: The conjugacy problem in groups of orientable geometrizable 3-manifolds

abstract:
  We prove that fundamental groups of orientable (geometrizable) 3-manifolds
have a solvable conjugacy problem.


title:
Swarming, Schooling, Milling: Phase diagram of a data-driven fish school
  model

abstract:
  We determine the basic phase diagram of the fish school model derived from
data by Gautrais etal (PLoS Comp. Biol. 8, e1002678 (2012)), exploring its
parameter space beyond the parameter values determined experimentally on groups
of barred flagtails (Kuhlia mugil}) swimming in a shallow tank. A modified
model is studied alongside the original one, in which an additional frontal
preference is introduced in the stimulus/response function to account for the
angular weighting of interactions. Our study, mostly limited to groups of
moderate size (in the order of 100 individuals), focused not only on the
transition to schooling induced by increasing the swimming speed, but also on
the conditions under which a school can exhibit milling dynamics and the
corresponding behavioral transitions. We show the existence of a transition
region between milling and schooling, in which the school exhibits
multistability and intermittency between schooling and milling for the same
combination of individuals parameters. We also show that milling does not occur
for arbitrarily large groups, mainly due to a distance dependence interaction
of the model and information propagation delays in the school, which cause
conflicting reactions for large groups. We finally discuss the biological
significance of our findings, especially the dependence of behavioural
transitions on social interactions, which were reported by Gautrais etal to be
adaptive in the experimental conditions.


title: Heat Conduction by Phonons across a Film

abstract:
  Quasiparticle theory gives a local relation between heat current and
temperature gradient, provided the quasiparticle mean free path is smaller than
the scale of variation of temperature. When mean free paths are comparable to
sample size, the relation becomes non-local. This non-local relation is
formulated for phonon carriers; an explicit form is found in the approximation
where current relaxation rates are replaced by quasiparticle relaxation rates.
A quasiparticle definition of local temperature is offered. To extract the
spatial variation of the temperature gradient requires inverting the non-local
relation. A variational principle is constructed. The heat current is bounded
above when evaluated for a trial temperature gradient. The true temperature
gradient is the one which minimizes heat current. The simplest variational
approximation (a constant temperature gradient) gives an approximate formula
for the thickness dependence of the heat transport across a film whose
thickness is comparable to mean free paths of phonons. The formula interpolates
between ballistic and diffusive limits.


title: Deterministic Integer Factorization Algorithms

abstract:
  A new integer deterministic factorization algorithm, rated at arithmetic
operations to $O(N^{1/6+\varepsilon})$ arithmetic operations, is presented in
this note. Equivalently, given the least $(\log N)/6$ bits of a factor of the
balanced integer $N = pq$, where $p$ and $q$ are primes, the algorithm factors
the integer in polynomial time $O(\log(N)^c)$, with $c \geq 0$ constant, and
$\varepsilon > 0$ an arbitrarily small number. It improves the current
deterministic factorization algorithm, rated at arithmetic operations to
$O(N^{1/5+\varepsilon})$ arithmetic operations.


title: Completeness Results for Parameterized Space Classes

abstract:
  The parameterized complexity of a problem is considered "settled" once it has
been shown to lie in FPT or to be complete for a class in the W-hierarchy or a
similar parameterized hierarchy. Several natural parameterized problems have,
however, resisted such a classification. At least in some cases, the reason is
that upper and lower bounds for their parameterized space complexity have
recently been obtained that rule out completeness results for parameterized
time classes. In this paper, we make progress in this direction by proving that
the associative generability problem and the longest common subsequence problem
are complete for parameterized space classes. These classes are defined in
terms of different forms of bounded nondeterminism and in terms of simultaneous
time--space bounds. As a technical tool we introduce a "union operation" that
translates between problems complete for classical complexity classes and for
W-classes.


title: Multiclass learnability and the ERM principle

abstract:
  We study the sample complexity of multiclass prediction in several learning
settings. For the PAC setting our analysis reveals a surprising phenomenon: In
sharp contrast to binary classification, we show that there exist multiclass
hypothesis classes for which some Empirical Risk Minimizers (ERM learners) have
lower sample complexity than others. Furthermore, there are classes that are
learnable by some ERM learners, while other ERM learners will fail to learn
them. We propose a principle for designing good ERM learners, and use this
principle to prove tight bounds on the sample complexity of learning {\em
symmetric} multiclass hypothesis classes---classes that are invariant under
permutations of label names. We further provide a characterization of mistake
and regret bounds for multiclass learning in the online setting and the bandit
setting, using new generalizations of Littlestone's dimension.


title:
Low-Complexity Sphere Decoding of Polar Codes based on Optimum Path
  Metric

abstract:
  Sphere decoding (SD) of polar codes is an efficient method to achieve the
error performance of maximum likelihood (ML) decoding. But the complexity of
the conventional sphere decoder is still high, where the candidates in a target
sphere are enumerated and the radius is decreased gradually until no available
candidate is in the sphere. In order to reduce the complexity of SD, a stack SD
(SSD) algorithm with an efficient enumeration is proposed in this paper. Based
on a novel path metric, SSD can effectively narrow the search range when
enumerating the candidates within a sphere. The proposed metric follows an
exact ML rule and takes the full usage of the whole received sequence.
Furthermore, another very simple metric is provided as an approximation of the
ML metric in the high signal-to-noise ratio regime. For short polar codes,
simulation results over the additive white Gaussian noise channels show that
the complexity of SSD based on the proposed metrics is up to 100 times lower
than that of the conventional SD.


title: Deformation of Striped Patterns by Inhomogeneities

abstract:
  We study the effects of adding a local perturbation in a pattern forming
system, taking as an example the Ginzburg-Landau equation with a small
localized inhomogeneity in two dimensions. Measuring the response through the
linearization at a periodic pattern, one finds an unbounded linear operator
that is not Fredholm due to continuous spectrum in typical translation
invariant or weighted spaces. We show that Kondratiev spaces, which encode
algebraic localization that increases with each derivative, provide an
effective means to circumvent this difficulty. We establish Fredholm properties
in such spaces and use the result to construct deformed periodic patterns using
the Implicit Function Theorem. We find a logarithmic phase correction which
vanishes for a particular spatial shift only, which we interpret as a
phase-selection mechanism through the inhomogeneity.


title: Two-boson composites

abstract:
  Composite bosons made of two bosonic constituents exhibit deviations from
ideal bosonic behavior due to their substructure. This deviation is reflected
by the normalization ratio of the quantum state of N composites. We find a set
of saturable, efficiently evaluable bounds for this indicator, which quantifies
the bosonic behavior of composites via the entanglement of their constituents.
We predict an abrupt transition between ordinary and exaggerated bosonic
behavior in a condensate of two-boson composites.


title: Spectral Singularities in the Surface Modes of a Spherical Gain Medium

abstract:
  We study the surface modes of a homogeneous spherical gain medium and provide
a comprehensive analytic treatment of a special class of these modes that
support spectral singularities. Because the latter have a divergent quality
factor, we call them the singular gallery modes. We show that they can be
excited using arbitrarily small amounts of gain, and as a result, the system
lacks a lasing threshold, effectively. This shows that we can realize spectral
singularities in the surface modes of extremely small spherical samples with
modest amounts of gain. We also examine the possibility of exciting singular
gallery modes with different wavelengths using the same amount of gain. This
corresponds to the situation where the system undergoes simultaneous lasing at
different wavelengths.


title: Digital instability of a confined elastic meniscus

abstract:
  Thin soft elastic layers serving as joints between relatively rigid bodies
may function as sealants, thermal, electrical, or mechanical insulators,
bearings, or adhesives. When such a joint is stressed, even though perfect
adhesion is maintained, the exposed free meniscus in the thin elastic layer
becomes unstable, leading to the formation of spatially periodic digits of air
that invade the elastic layer, reminiscent of viscous fingering in a thin fluid
layer. How- ever, the elastic instability is reversible and rate-independent,
dis- appearing when the joint is unstressed. We use theory, experiments, and
numerical simulations to show that the transition to the digital state is
sudden (first-order), the wavelength and amplitude of the fingers are
proportional to the thickness of the elastic layer, and the required separation
to trigger the instability is inversely proportional to the in-plane dimension
of the layer. Our study reveals the energetic origin of this instability and
has implications for the strength of polymeric adhesives; it also suggests a
method for patterning thin films reversibly with any arrangement of localized
fingers in a digital elastic memory, which we confirm experimentally.


title: On non-isotopic spanning surfaces for a class of arborescent knots

abstract:
  We use the methods of Hedden, Juhasz, and Sarkar to exhibit a set of
arborescent knots that bound large numbers of non-isotopic minimal genus
spanning surfaces. In particular, we describe a sequence of prime knots K_{n}
which will bound at least 2^{2n-1} non-isotopic minimal spanning surfaces of
genus n.


title: On some determinants with Legendre symbol entries

abstract:
  In this paper we mainly focus on some determinants with Legendre symbol
entries. Let $p$ be an odd prime and let $(\frac{\cdot}p)$ be the Legendre
symbol. We show that $(\frac{-S(d,p)}p)=1$ for any $d\in\mathbb Z$ with $(\frac
dp)=1$, and that $$\left(\frac{W_p}p\right)=\begin{cases}(-1)^{|\{0<k<\frac
p4:\ (\frac kp)=-1\}|}&\text{if}\ p\equiv1\pmod4,
\\(-1)^{\lfloor(p+1)/8\rfloor}&\text{if}\ p\equiv3\pmod4,\end{cases}$$ where
$$S(d,p)=\det\left[\left(\frac{i^2+dj^2}p\right)\right]_{1\le i,j\le(p-1)/2}$$
and $$W_p=\det\left[\left(\frac{i^2-((p-1)/2)!j}p\right)\right]_{0\le
i,j\le(p-1)/2}.$$ We also pose some conjectures on determinants, one of which
states that $(-1)^{\lfloor(p+1)/8\rfloor}W_p$ is a square when $p\equiv
3\pmod4$.


title:
High energy photoelectron emission from gases using plasmonics enhanced
  near-fields

abstract:
  We study theoretically the photoelectron emission in noble gases using
plasmonic enhanced near-fields. We demonstrate that these fields have a great
potential to generate high energy electrons by direct mid-infrared laser pulses
of the current femtosecond oscillator. Typically, these fields appear in the
surroundings of plasmonic nanostructures, having different geometrical shape
such as bow-ties, metallic waveguides, metal nanoparticles and nanotips, when
illuminated by a short laser pulse. In here, we consider metal nanospheres, in
which the spatial decay of the near-field of the isolated nanoparticle can be
approximated by an exponential function according to recent attosecond
streaking measurements. We establish that the strong nonhomogeneous character
of the enhanced near-field plays an important role in the above threshold
ionization (ATI) process and leads to a significant extension in the
photoelectron spectra. In this work, we employ the time dependent Schr\"odinger
equation in reduced dimensions to calculate the photoelectron emission of xenon
atoms in such enhanced near-field. Our findings are supported by classical
calculations.


title: Enumeration of curves with one singular point

abstract:
  In this paper we obtain an explicit formula for the number of degree d curves
in two dimensional complex projective space, passing through (d(d+3)/2 -k)
generic points and having a codimension k singularity, where k is at most 7. In
the past, many of these numbers were computed using techniques from algebraic
geometry. In this paper we use purely topological methods to count curves. Our
main tool is a classical fact from differential topology: the number of zeros
of a generic smooth section of a vector bundle V over M, counted with a sign,
is the Euler class of V evaluated on the fundamental class of M.


title:
ConXsense - Automated Context Classification for Context-Aware Access
  Control

abstract:
  We present ConXsense, the first framework for context-aware access control on
mobile devices based on context classification. Previous context-aware access
control systems often require users to laboriously specify detailed policies or
they rely on pre-defined policies not adequately reflecting the true
preferences of users. We present the design and implementation of a
context-aware framework that uses a probabilistic approach to overcome these
deficiencies. The framework utilizes context sensing and machine learning to
automatically classify contexts according to their security and privacy-related
properties. We apply the framework to two important smartphone-related use
cases: protection against device misuse using a dynamic device lock and
protection against sensory malware. We ground our analysis on a sociological
survey examining the perceptions and concerns of users related to contextual
smartphone security and analyze the effectiveness of our approach with
real-world context data. We also demonstrate the integration of our framework
with the FlaskDroid architecture for fine-grained access control enforcement on
the Android platform.


title: Theoretical analysis for the optical deformation of emulsion droplets

abstract:
  We propose a theoretical framework to predict the three-dimensional shapes of
optically deformed micron-sized emulsion droplets with ultra-low interfacial
tension. The resulting shape and size of the droplet arises out of a balance
between the interfacial tension and optical forces. Using an approximation of
the laser field as a Gaussian beam, working within the Rayleigh-Gans regime and
assuming isotropic surface energy at the oil-water interface, we numerically
solve the resulting shape equations to elucidate the three-dimensional droplet
geometry. We obtain a plethora of shapes as a function of the number of optical
tweezers, their laser powers and positions, surface tension, initial droplet
size and geometry. Experimentally, two-dimensional droplet silhouettes have
been imaged from above, but their full side-on view has not been observed and
reported for current optical configurations. This experimental limitation
points to ambiguity in differentiating between droplets having the same
two-dimensional projection but with disparate three-dimensional shapes. Our
model elucidates and quantifies this difference for the first time. We also
provide a dimensionless number that indicates the shape transformation
(ellipsoidal to dumbbell) at a value $\approx 1.0$, obtained by balancing
interfacial tension and laser forces, substantiated using a data collapse.


title: On cycles for the doubling map which are disjoint from an interval

abstract:
  Let $T:[0,1]\to[0,1]$ be the doubling map and let $0<a<b<1$. We say that an
integer $n\ge3$ is bad for $(a,b)$ if all $n$-cycles for $T$ intersect $(a,b)$.
Let $B(a,b)$ denote the set of all $n$ which are bad for $(a,b)$. In this paper
we completely describe the sets: \[ D_2=\{(a,b) : B(a,b)\,\text{is finite}\} \]
and \[ D_3=\{(a,b) : B(a,b)=\varnothing\}. \] In particular, we show that if
$b-a<\frac16$, then $(a,b)\in D_2$, and if $b-a\le\frac2{15}$, then $(a,b)\in
D_3$, both constants being sharp.


title: Large-x connections of nuclear and high-energy physics

abstract:
  I discuss how global QCD fits of parton distribution functions can make the
somewhat separated fields of high-energy particle physics and lower energy
hadronic and nuclear physics interact to the benefit of both. I review specific
examples of this interplay from recent works of the CTEQ-Jefferson Lab
collaboration, including hadron structure at large parton momentum and gauge
boson production at colliders. I devote particular attention to quantifying
theoretical uncertainties arising in the treatment of large partonic momentum
contributions to deep inelastic scattering observables, and to discussing the
experimental progress needed to reduce these.


title:
A Survey of Protocols for Intermittently Connected Delay-Tolerant
  Wireless Sensor Networks

abstract:
  Intermittently Connected Delay-Tolerant Wireless Sensor Networks (ICDT-WSNs),
a branch of Wireless Sensor Networks (WSNs), have features of WSNs and the
intermittent connectivity of Delay-Tolerant Networks (DTNs). The applications
of ICDT-WSNs are increasing in recent years, however, the communication
protocols suitable for this category of networks often fall short. Most of the
existing communication protocols are designed for either WSNs or DTNs and tend
to be inadequate for direct use in ICDT-WSNs. This survey summarizes
characteristics of ICDT-WSNs and their communication protocol requirements, and
examines the communication protocols designed for WSNs and DTNs in recent years
from the perspective of ICDT-WSNs. Opportunities for future research in
ICDT-WSNs are also outlined.


title:
Doping influence of spin dynamics and magnetoelectric effect in
  hexagonal Y$_{0.7}$Lu$_{0.3}$MnO$_{3}$

abstract:
  We use inelastic neutron scattering to study spin waves and their correlation
with the magnetoelectric effect in Y$_{0.7}$Lu$_{0.3}$MnO$_3$. In the undoped
YMnO$_3$ and LuMnO$_3$, the Mn trimerization distortion has been suggested to
play a key role in determining the magnetic structure and the magnetoelectric
effect. In Y$_{0.7}$Lu$_{0.3}$MnO$_3$, we find a much smaller in-plane
(hexagonal $ab$-plane) single ion anisotropy gap that coincides with a weaker
in-plane dielectric anomaly at $T_N$. Since both the smaller in-plane
anisotropy gap and the weaker in-plane dielectric anomaly are coupled to a
weaker Mn trimerization distortion in Y$_{0.7}$Lu$_{0.3}$MnO$_3$ comparing to
YMnO$_3$ and LuMnO$_3$, we conclude that the Mn trimerization is responsible
for the magnetoelectric effect and multiferroic phenomenon in
Y$_{1-y}$Lu$_{y}$MnO$_{3}$.


title:
Anatomy of perpendicular magnetic anisotropy in Fe/MgO magnetic tunnel
  junctions: First principles insight

abstract:
  Using first-principles calculations, we elucidate microscopic mechanisms of
perpendicular magnetic anisotropy (PMA)in Fe/MgO magnetic tunnel junctions
through evaluation of orbital and layer resolved contributions into the total
anisotropy value. It is demonstrated that the origin of the large PMA values is
far beyond simply considering the hybridization between Fe-3d$ and O-2p
orbitals at the interface between the metal and the insulator. On-site
projected analysis show that the anisotropy energy is not localized at the
interface but it rather propagates into the bulk showing an attenuating
oscillatory behavior which depends on orbital character of contributing states
and interfacial conditions. Furthermore, it is found in most situations that
states with $d_{yz(xz)}$ and $d_{z^2}$ character tend always to maintain the
PMA while those with $d_{xy}$ and $d_{x^2-y^2}$ character tend to favor the
in-plane anisotropy. It is also found that while MgO thickness has no influence
on PMA, the calculated perpendicular magnetic anisotropy oscillates as a
function of Fe thickness with a period of 2ML and reaches a maximum value of
3.6 mJ/m$^2$.


title:
Nitsche's method method for mixed dimensional analysis: conforming and
  non-conforming continuum-beam and continuum-plate coupling

abstract:
  A Nitche's method is presented to couple different mechanical models. They
include coupling of a solid and a beam and of a solid and a plate. Both
conforming and non-conforming formulations are presented. In a non-conforming
for- mulation, the structure domain is overlapped by a refined solid model.
Applications can be found in multi-dimensional analyses in which parts of a
structure are modeled with solid elements and others are modeled using a
coarser model with beam and/or plate elements. Discretisations are performed
using both standard Lagrange elements and high order NURBS (Non Uniform
Rational Bsplines) based isogeometric elements. We present various examples to
demonstrate the performance of the method.


title: Test of consistency between Planck and WMAP

abstract:
  Within the context of the concordance model of cosmology we test the
consistency of the angular power spectrum data from WMAP and Planck looking for
possible systematics. The best fit concordance model to each observation is
used as a mean function along with a Crossing function with an orthogonal basis
to fit the data from the other observation searching for any possible
deviation. We report that allowing an overall amplitude shift in the observed
angular power spectra of the two observations, the best fit mean function from
Planck data is consistent with WMAP 9 year data but the best fit mean function
generated from WMAP-9 data is not consistent with Planck data at the $3\sigma$
level. This is an expected result when there is no clear systematic/tension
between two observations and one of them has a considerably higher precision.
We conclude that there is no clear tension between Planck and WMAP 9 year
angular power spectrum data from a statistical point of view (allowing the
overall amplitude shift). Our result highlights the fact that while the angular
power spectrum from cosmic microwave background observations is a function of
various cosmological parameters, comparing individual parameters might be
misleading in the presence of cosmographic degeneracies. Another main result of
our analysis is the importance of the overall amplitudes of the observed
spectra from Planck and WMAP observations. Fixing the amplitudes at their
reported values results in an unresolvable tension between the two observations
at more than $3\sigma$ level which can be a hint towards a serious systematic.


title: Service Discovery -- A Survey and Comparison

abstract:
  With the increasing number of services in the internet, companies intranets,
and home networks: service discovery becomes an integral part of modern
networked system. This paper provides a comprehensive survey of major solutions
for service discovery. We cover techniques and features used in existing
systems. Although a few survey articles have been published on this object, our
contribution focuses on comparing and analyzing surveyed solutions according
eight prime criteria, which we have defined before. This comparison will be
helpful to determine limits of existing discovery protocols and identify future
research opportunities in service discovery.


title: Variational Quantum Electrodynamics

abstract:
  A variational method is discussed, based on the principle of minimal
variance. The method seems to be suited for gauge interacting fermions, and the
simple case of quantum electrodynamics is discussed in detail. The issue of
renormalization is addressed, and the renormalized propagators are shown to be
the solution of a set of finite integral equations. The method is proven to be
viable and, by a spectral representation, the multi-dimensional integral
equations are recast in one-dimensional equations for the spectral weights. The
UV divergences are subtracted exactly, yielding a set of coupled Volterra
integral equations that can be solved iteratively, and are known to have a
unique solution.


title:
Grids of stellar models with rotation - III. Models from 0.8 to 120 Msun
  at a metallicity Z = 0.002

abstract:
  (shortened) We provide a grid of single star models covering a mass range
from 0.8 to 120 Msun with an initial metallicity Z = 0.002 with and without
rotation. We discuss the impact of a change in the metallicity by comparing the
current tracks with models computed with exactly the same physical ingredients
but with a metallicity Z = 0.014 (solar). We show that the width of the
main-sequence (MS) band in the upper part of the Hertzsprung-Russell diagram
(HRD), for luminosity above log(L/Lsun) > 5.5, is very sensitive to rotational
mixing. Strong mixing significantly reduces the MS width. We confirm, but here
for the first time on the whole mass range, that surface enrichments are
stronger at low metallicity provided that comparisons are made for equivalent
initial mass, rotation and evolutionary stage. We show that the enhancement
factor due to a lowering of the metallicity (all other factors kept constant)
increases when the initial mass decreases. Present models predict an upper
luminosity for the red supergiants (RSG) of log (L/Lsun) around 5.5 at Z =
0.002 in agreement with the observed upper limit of RSG in the Small Magellanic
Cloud. We show that models using shear diffusion coefficient calibrated to
reproduce the surface enrichments observed for MS B-type stars at Z = 0.014 can
also reproduce the stronger enrichments observed at low metallicity. In the
framework of the present models, we discuss the factors governing the timescale
of the first crossing of the Hertzsprung gap after the MS phase. We show that
any process favouring a deep localisation of the H-burning shell (steep
gradient at the border of the H-burning convective core, low CNO content)
and/or the low opacity of the H-rich envelope favour a blue position in the HRD
for the whole or at least a significant fraction of the core He-burning phase.


title: A Strange Family of Calabi-Yau 3-folds

abstract:
  We study the predictions of mirror symmetry for the 1-parameter family of
Calabi-Yau 3-folds $\tilde{X}$ with hodge numbers $h^{11}=31,h^{21}=1$
constructed in \cite{BN}. We calculate the Picard-Fuchs differential equation
associated to this family, and use it to predict the instanton numbers on the
hypothetical mirror. These exhibit a strange vanishing in odd degrees. We also
calculate the monodromy action on $H^3(\tilde{X},\QQ)$ and find that it
strangely predicts a positive Euler characteristic for its mirror. From a
degenerate fiber of our family we construct a new rigid Calabi-Yau 3-fold. In
an appendix we prove the expansion of the conifold period conjectured in
\cite{ES} to hold for all 1-parameter families.


title: Singlet Excited States of Anions with Higher Main Group Elements

abstract:
  Previous studies have shown that dipole-bound excited states exist for
certain small anions. However, valence excited states have been reported for
some closed-shell anions, but those with singlet valence excited states have,
thus far, contained a single silicon atom. This work utilizes high-level
coupled cluster theory previously shown to reproduce excited state energies to
better than 0.1 eV compared with experiment in order to examine the electronic
excited state properties of anions containing silicon and other higher main
group atoms as well as their first row analogues. Of the fourteen anions
involved in this study, nine possess bound excited states of some kind:
CH$_2$SN$^-$, C$_3$H$^-$, CCSiH$^-$, CCSH$^-$, CCNH$_2^-$, CCPH$_2^-$,
BH$_3$PH$_2^-$, AlH$_3$NH$_2^-$, and AlH$_3$PH$_2^-$. Two possess clear valence
states: CCSiH$^-$ and its first row analogue C$_3$H$^-$. Substantial mixing
appears to be present in the valence and dipole-bound characters for the first
excited state wavefunctions of many of the systems reporting excited states,
but the mixing is most pronounced with the ammonia borane-like AlH$_3$NH$_2^-$,
and AlH$_3$PH$_2^-$ anions. Inclusion of second row atoms in anions whose
corresponding radical is strongly dipolar increases the likelihood for the
existence of excited states of any kind, but among the systems considered to
date with this methodology, only the nature of group 14 atoms in small,
closed-shell anions has yet been shown to allow valence singlet excited states.


title: Hilbert regularity of ZZ-graded modules over polynomial rings

abstract:
  Let M be a finitely generated ZZ-graded module over the standard graded
polynomial ring R=K[X_1, ..., X_n] with K a field, and let
H_M(t)=Q_M(t)/(1-t)^d be the Hilbert series of M. We introduce the Hilbert
regularity of M as the lowest possible value of the Castelnuovo-Mumford
regularity for an R-module with Hilbert series H_M. Our main result is an
arithmetical description of this invariant which connects the Hilbert
regularity of M to the smallest k such that the power series Q_M(1-t)/(1-t)^k
has no negative coefficients. Finally we give an algorithm for the computation
of the Hilbert regularity and the Hilbert depth of an R-module.


title: Higher-order Fourier dimension and frequency decompositions

abstract:
  This paper continues work begun in \cite{M1}, in which we introduced a theory
of Gowers uniformity norms for singular measures on $\mathbb{R}^d$. There,
given a $d$-dimensional measure $\mu$, we introduced a $(k+1)d$-dimensional
measure $\triangle^k\mu$, and developed a Uniformity norm $\|\mu\|_{U^k}$ whose
$2^k$-th power is equivalent to $\triangle^k\mu([0,1]^{d(k+1)}$. In the present
work, we introduce a fractal dimension associated to measures $\mu$ which we
refer to as the $k$th-order Fourier dimension of $\mu$. This $k$-th order
Fourier dimension is a normalization of the asymptotic decay rate of the
Fourier transform of the measure $\int \triangle^k\mu(x;\cdot)\,dx$, and
coincides with the classic Fourier dimension in the case that $k=1$. It
provides quantitative control on the size of the $U^k$ norm. The main result of
the present paper is that this higher-order Fourier dimension controls the rate
at which $\|\mu-\mu_n\|_{U^k}\rightarrow 0$, where $\mu_n$ is an approximation
to the measure $\mu$. This allows us to extract delicate information from the
Fourier transform of a measure $\mu$ and the interactions of its frequency
components, which is not available from the $L^p$ norms- or the decay- of the
Fourier transform. In future work \cite{M4}, we apply this to obtain a
differentiation theorem for singular measures.


title: Long progressions in sets of fractional dimension

abstract:
  We demonstrate $k+1$-term arithmetic progressions in certain subsets of the
real line whose "higher-order Fourier dimension" is sufficiently close to 1.
This Fourier dimension, introduced in previous work, is a higher-order (in the
sense of Additive Combinatorics and uniformity norms) extension of the Fourier
dimension of Geometric Measure Theory, and can be understood as asking that the
uniformity norm of a measure, restricted to a given scale, decay as the scale
increases. We further obtain quantitative information about the size and $L^p$
regularity of the set of common distances of the artihmetic progressions
contained in the subsets of $\mathbb{R}$ under consideration.


title: As-puma ; anycast semantics in parking using metaheuristic approach

abstract:
  The number of vehicle used in the world are increasing day by day resulting
in the obvious problem of parking of these vehicles in residential and
vocational areas. We perceive the problem of vehicles parking in vocational
establishments / malls. Today majority of parking systems are manual parking
systems where in, on the spot, parking of the vehicle is done and a parking
slip is generated and handed over to customer. This is cumbersome technique
wherein various parking attendants in the parking areas manually keeps on
informing the Parking inspector on how many free parking slots available so
that only that many number of parking slips/tickets are generated as the number
of free parking slots. We address the problem of parking in Delay Tolerant
Network (DTN) by proposing metaheuristic driven approach of Ant Colony
optimization (ACO) technique with anycast semantics models . Here we propose
the parking architecture to solve the problem of parking especially in
commercial areas with their design diagrams . In this architecture we apply the
delivery model to deliver the packet correctly to the intended receiver. Using
this we can book various parkings through remote areas so that the customer can
get the information about availability of various parkings inside an area and
the parking fare for each category of the automobile. Using this architecture
the customer can get the prior knowledge about various vacant parking slots
inside a parking area and he can book the corresponding parking from his
location.


title:
Extended Capabilities for a Privacy-Enhanced Participatory Sensing
  Infrastructure (PEPSI)

abstract:
  Participatory sensing is emerging as an innovative computing paradigm that
targets the ubiquity of always-connected mobile phones and their sensing
capabilities. In this context, a multitude of pioneering applications
increasingly carry out pervasive collection and dissemination of information
and environmental data, such as, traffic conditions, pollution, temperature,
etc. Participants collect and report measurements from their mobile devices and
entrust them to the cloud to be made available to applications and users.
Naturally, due to the personal information associated to the reports (e.g.,
location, movements, etc.), a number of privacy concerns need to be taken into
account prior to a large-scale deployment of these applications. Motivated by
the need for privacy protection in Participatory Sensing, this work presents
PEPSI: a Privacy-Enhanced Participatory Sensing Infrastructure. We explore
realistic architectural assumptions and a minimal set of formal requirements
aiming at protecting privacy of both data producers and consumers. We propose
two instantiations that attain privacy guarantees with provable security at
very low additional computational cost and almost no extra communication
overhead.


title: RAMBO on diet

abstract:
  We describe a phase space generator which is flat for massless particles, and
approximately flat for massive particles of masses much smaller than the
typical mometum scales involved in the process. The same goal is achieved by
the RAMBO algorithm, contrary to which our approach does only require the
minimal number of degrees of freedom and is invertible in the sense that it
provides a unique mapping of random numbers to the physical phase space point
and vice versa. The very motivation to seek such an algorithm is explained in
detail.


title:
Robotic Message Ferrying for Wireless Networks using Coarse-Grained
  Backpressure Control

abstract:
  We formulate the problem of robots ferrying messages between
statically-placed source and sink pairs that they can communicate with
wirelessly. We first analyze the capacity region for this problem under both
ideal (arbitrarily high velocity, long scheduling periods) and realistic
conditions. We indicate how robots could be scheduled optimally to satisfy any
arrival rate in the capacity region, given prior knowledge about arrival rates.
We find that if the number of robots allocated grows proportionally with the
number of source-sink pairs, then the capacity of the network scales as
$\Theta(1)$, similar to what was shown previously by Grossglauser and Tse for
uncontrolled mobility; however, in contrast to that prior result, we also find
that with controlled mobility this constant capacity scaling can be obtained
while ensuring finite delay. We then consider the setting where the arrival
rates are unknown and present a coarse-grained backpressure message ferrying
algorithm (CBMF) for it. In CBMF, the robots are matched to sources and sinks
once every epoch to maximize a queue-differential-based weight. The matching
controls both motion and transmission for each robot: if a robot is matched to
a source, it moves towards that source and collects data from it; and if it is
matched to a sink, it moves towards that sink and transmits data to it. We show
through analysis and simulations the conditions under which CBMF can stabilize
the network. We show that the maximum achievable stable throughput with this
policy tends to the ideal capacity as the schedule duration and robot velocity
increase.


title:
An apparatus for studying spallation neutrons in the Aberdeen Tunnel
  laboratory

abstract:
  In this paper, we describe the design, construction and performance of an
apparatus installed in the Aberdeen Tunnel laboratory in Hong Kong for studying
spallation neutrons induced by cosmic-ray muons under a vertical rock
overburden of 611 meter water equivalent (m.w.e.). The apparatus comprises of
six horizontal layers of plastic-scintillator hodoscopes for determining the
direction and position of the incident cosmic-ray muons. Sandwiched between the
hodoscope planes is a neutron detector filled with 650 kg of liquid
scintillator doped with about 0.06% of Gadolinium by weight for improving the
efficiency of detecting the spallation neutrons. Performance of the apparatus
is also presented.


title: Glueball and meson spectrum in large-N massless QCD

abstract:
  We provide outstanding numerical evidence that in large-N massless QCD the
joint spectrum of the masses squared, for fixed integer spin s and unspecified
parity and charge conjugation, obeys exactly the following laws: m_k^2 =
(k+s/2) Lambda_QCD^2 for s even, m_k^2 = 2(k+s/2) Lambda_QCD^2 for s odd, k =
1,2,... for glueballs, and m_n^2 = 1/2 (n+s/2) Lambda_QCD^2, n = 0,1,... for
mesons. One of the striking features of these laws is that they imply that the
glueball and meson masses squared form exactly-linear Regge trajectories in the
large-N limit of massless QCD, all the way down to the low-lying states: A fact
unsuspected so far. The numerical evidence is based on lattice computations by
Meyer-Teper in SU(8) YM for glueballs, and by Bali et al. in SU(17) quenched
massless QCD for mesons, that we analyze systematically. The aforementioned
spectrum for spin-0 glueballs is implied by a Topological Field Theory
underlying the large-N limit of YM, whose glueball propagators satisfy as well
fundamental universal constraints arising from the asymptotic freedom and the
renormalization group. No other presently existing model meets both the
infrared spectrum and the ultraviolet constraints. We argue that some features
of the aforementioned spectrum of glueballs and mesons of any spin could be
explained by the existence of a Topological String Theory dual to the
Topological Field Theory.


title:
Topological Field Theory on a Lattice, Discrete Theta-Angles and
  Confinement

abstract:
  We study a topological field theory describing confining phases of gauge
theories in four dimensions. It can be formulated on a lattice using a discrete
2-form field talking values in a finite abelian group (the magnetic gauge
group). We show that possible theta-angles in such a theory are quantized and
labeled by quadratic functions on the magnetic gauge group. When the
theta-angles vanish, the theory is dual to an ordinary topological gauge
theory, but in general it is not isomorphic to it. We also explain how to
couple a lattice Yang-Mills theory to a TQFT of this kind so that the 't Hooft
flux is well-defined, and quantized values of the theta-angles are allowed. The
quantized theta-angles include the discrete theta-angles recently identified by
Aharony, Seiberg and Tachikawa.


title: Robust estimation on a parametric model via testing

abstract:
  We are interested in the problem of robust parametric estimation of a density
from $n$ i.i.d. observations. By using a practice-oriented procedure based on
robust tests, we build an estimator for which we establish non-asymptotic risk
bounds with respect to the Hellinger distance under mild assumptions on the
parametric model. We show that the estimator is robust even for models for
which the maximum likelihood method is bound to fail. A numerical simulation
illustrates its robustness properties. When the model is true and regular
enough, we prove that the estimator is very close to the maximum likelihood
one, at least when the number of observations $n$ is large. In particular, it
inherits its efficiency. Simulations show that these two estimators are almost
equal with large probability, even for small values of $n$ when the model is
regular enough and contains the true density.


title: Investigating the limits of randomized benchmarking protocols

abstract:
  In this paper, we analyze the performance of randomized benchmarking
protocols on gate sets under a variety of realistic error models that include
systematic rotations, amplitude damping, leakage to higher levels, and 1/f
noise. We find that, in almost all cases, benchmarking provides better than a
factor-of-two estimate of average error rate, suggesting that randomized
benchmarking protocols are a valuable tool for verification and validation of
quantum operations. In addition, we derive new models for fidelity decay curves
under certain types of non-Markovian noise models such as 1/f and leakage
errors. We also show that, provided the standard error of the fidelity
measurements is small, only a small number of trials are required for high
confidence estimation of gate errors.


title: Cosmologia e Representa\c{c}\~ao

abstract:
  This work presents a brief and non-technical description of the main results
and concepts of the modern scientific cosmology, viewing it from an
epistemological perspective which allows a dialog with other modes of thinking
like e.g. history, philosophy, sociology and religion. This epistemological
viewpoint is based on the philosophical theses advanced by Ludwig Boltzmann
(1844-1906) which states that scientific theories are nothing more than
representations, or images, of nature (arXiv:physics/0701308v1). By being
representations one cannot know how nature really is because the intrinsic and
indispensable properties that characterize nature are unreachable by science.
In other words, the true essences that constitute nature are unknowable.
Therefore, all answers proposed by science are partial, simplified and
replaceable. Another way of putting forward this viewpoint is to state that all
scientific truths are provisional, a result which naturally leads to the
conclusion that the same set of phenomena, or scientific questions, may have
various answers, or representations. This conclusion is generally known as
theoretical pluralism (arXiv:physics/9806011). It is exactly such a plurality
for conceiving, or representing, nature that opens the way for a possibly
fruitful dialog among the various forms of thinking, since this dialog can take
place in the realm of the representations. A few examples taken from cosmology,
sociology and theology are discussed in the context of this epistemological
framework.


title:
Semistability-Based Convergence Analysis for Paracontracting Multiagent
  Coordination Optimization

abstract:
  This sequential technical report extends some of the previous results we
posted at arXiv:1306.0225.


title: Graphene-Based Non-Boolean Logic Circuits

abstract:
  Graphene revealed a number of unique properties beneficial for electronics.
However, graphene does not have an energy band-gap, which presents a serious
hurdle for its applications in digital logic gates. The efforts to induce a
band-gap in graphene via quantum confinement or surface functionalization have
not resulted in a breakthrough. Here we show that the negative differential
resistance experimentally observed in graphene field-effect transistors of
"conventional" design allows for construction of viable non-Boolean
computational architectures with the gap-less graphene. The negative
differential resistance - observed under certain biasing schemes - is an
intrinsic property of graphene resulting from its symmetric band structure. Our
atomistic modeling shows that the negative differential resistance appears not
only in the drift-diffusion regime but also in the ballistic regime at the
nanometer-scale - although the physics changes. The obtained results present a
conceptual change in graphene research and indicate an alternative route for
graphene's applications in information processing.


title: Electroweak Higgs plus Three Jet Production at NLO QCD

abstract:
  We calculate next-to-leading order (NLO) QCD corrections to electroweak Higgs
plus three jet production. Both vector boson fusion (VBF) and Higgs-strahlung
type contributions are included along with all interferences. The calculation
is implemented within the Matchbox NLO framework of the Herwig++ event
generator.


title:
Strain effects on electronic structure of the iron selenide
  superconductor

abstract:
  The influence of various strains on crystal and electronic structures of
superconducting FeSe has been studied ab initio. We consider changes in the
Fermi surface nesting with a vector Q=(0.5,0.5)*(2\pi /a) as crucial for rising
superconductivity (SC) mediated by spin-fluctuations (SF). Our results indicate
that the c-axis strained FeSe exhibits the most imperfect nesting, which
enhances SF and, hence, also SC. In turn, the ab-plane compressive strain
slightly weakens this} nesting while the tensile strain destroys it completely.
These findings are consistent with reported earlier experimental dependencies
of superconducting transition temperatures on strain in FeSe thin films.


title:
The Fundamental Group of a Spatial Section Represented by a Topspin
  Network

abstract:
  We present an algorithm which determines the fundamental group of a spatial
section using topspin networks. Tracking the topology of the spatial section is
a unique feature of this approach, which is not possible in standard Loop
Quantum Gravity. This leads to an example of spatial topology change in a
smooth 4-manifold represented by a topspin foam.


title: Homology of polyhedra and quadrangulations of surfaces

abstract:
  A new formula is obtained in algebraic topology, in terms of Betti numbers,
and a new method, called the spinal method, is suggested and developed for
generating quadrangulations of closed orientable surfaces. Those surfaces arise
as the thickenings of 1- and 2-dimensional curvilinear polyhedra, called
spines, in Euclidean 3-space. By way of spinal manipulation, quadrangulations
with given properties are constructed.


title: Equivalence Principle and Bound Kinetic Energy

abstract:
  We consider the role of the internal kinetic energy of bound systems of
matter in tests of the Einstein equivalence principle. Using the gravitational
sector of the standard model extension, we show that stringent limits on
equivalence principle violations in antimatter can be indirectly obtained from
tests using bound systems of normal matter. We estimate the bound kinetic
energy of nucleons in a range of light atomic species using Green's function
Monte Carlo calculations, and for heavier species using a Woods-Saxon model. We
survey the sensitivities of existing and planned experimental tests of the
equivalence principle, and report new constraints at the level of between a few
parts in $10^{6}$ and parts in $10^{8}$ on violations of the equivalence
principle for matter and antimatter.

categories: gr-qc hep-ph nucl-th physics.atom-ph quant-ph


title:
HAT-P-44b, HAT-P-45b, and HAT-P-46b: Three Transiting Hot Jupiters in
  Possible Multi-Planet Systems

abstract:
  We report the discovery by the HATNet survey of three new transiting
extrasolar planets orbiting moderately bright (V=13.2, 12.8 and 11.9) stars.
The planets have orbital periods of 4.3012, 3.1290, and 4.4631 days, masses of
0.39, 0.89, and 0.49 Mjup, and radii of 1.28, 1.43, and 1.28 Rjup. The stellar
hosts have masses of 0.94, 1.26, and 1.28 Msun. Each system shows significant
systematic variations in its residual radial velocities indicating the possible
presence of additional components. Based on its Bayesian evidence, the
preferred model for HAT-P-44 consists of two planets, including the transiting
component, with the outer planet having a period of 220 d and a minimum mass of
1.6 Mjup. Due to aliasing we cannot rule out an alternative solution for the
outer planet having a period of 438 d and a minimum mass of 3.7 Mjup. For
HAT-P-45 at present there is not enough data to justify the additional free
parameters included in a multi-planet model, in this case a single-planet
solution is preferred, but the required jitter of 22.5 +- 6.3 m/s is relatively
high for a star of this type. For HAT-P-46 the preferred solution includes a
second planet having a period of 78 d and a minimum mass of 2.0 Mjup, however
the preference for this model over a single-planet model is not very strong.
While substantial uncertainties remain as to the presence and/or properties of
the outer planetary companions in these systems, the inner transiting planets
are well characterized with measured properties that are fairly robust against
changes in the assumed models for the outer planets. Continued RV monitoring is
necessary to fully characterize these three planetary systems, the properties
of which may have important implications for understanding the formation of hot
Jupiters.


title:
ERP projects Internal Stakeholder network and how it influences the
  projects outcome

abstract:
  So far little effort has been put into researching the importance of internal
ERP project stakeholders mutual interactions,realizing the projects
complexity,influence on the whole organization, and high risk for a useful
final outcome. This research analyzes the stakeholders interactions and
positions in the project network, their criticality, potential bottlenecks and
conflicts. The main methods used are Social Network Analysis, and the
elicitation of drivers for the individual players. Information was collected
from several stakeholders from three large ERP projects all in global companies
headquartered in Finland, together with representatives from two different ERP
vendors, and with two experienced ERP consultants. The analysis gives
quantitative as well as qualitative characterization of stakeholder criticality
(mostly the Project Manager(s), the Business Owner(s) and the Process
Owner(s)), degree of centrality, closeness, mediating or bottleneck roles,
relational ties and conflicts (individual, besides those between business and
project organizations), and clique formations. A generic internal stakeholder
network model is established as well as the criticality of the project phases.
The results are summarized in the form of a list of recommendations for future
ERP projects to address the internal stakeholder impacts .Project management
should utilize the latest technology to provide tools to increase the
interaction between the stakeholders and to monitor the strength of these
relations. Social network analysis tools could be used in the projects to
visualize the stakeholder relations in order to better understand the possible
risks related to the relations (or lack of them).


title: Relative entropy is an exact measure of non-Gaussianity

abstract:
  We prove that the closest Gaussian state to an arbitrary $N$-mode field state
through the relative entropy is built with the covariance matrix and the
average displacement of the given state. Consequently, the relative entropy of
an $N$-mode state to its associate Gaussian one is an exact distance-type
measure of non-Gaussianity. In order to illustrate this finding, we discuss the
general properties of the $N$-mode Fock-diagonal states and evaluate their
exact entropic amount of non-Gaussianity.


title:
Mobile operators as banks or vice-versa? and: regulators interest in the
  best efficiency for payments

abstract:
  This paper addresses the strategic challenges of deposit banks, and payment
clearinghouses, posed by the growing role of mobile operators as collectors and
payment agents for flows of cash for themselves and third parties. Through
analysis and data analysis from selected operators, it is shown that mobile
operators achieve as money flow handlers levels of efficiency,
profitability,and risk control comparable with deposit banks. Furthermore, the
payment infrastructures deployed by both are found to be quite similar, and are
analyzed in relation to financial profitability, strategic challenges and
opportunities. This paves the way to either mobile operators taking a bigger
role,or for banks to tie up such operators to them even more tightly,or for
alliances/mergers to take place,all these options being subject to regulatory
evolution which is analyzed as well . The consequences are mapped out in
operational and regulatory terms


title: Nuclear dimension and Z-stability of non-simple C*-algebras

abstract:
  We investigate the interplay of the following regularity properties for
non-simple C*-algebras: finite nuclear dimension, Z-stability, and algebraic
regularity in the Cuntz semigroup. We show that finite nuclear dimension
implies algebraic regularity in the Cuntz semigroup, provided that known type I
obstructions are avoided. We demonstrate how finite nuclear dimension can be
used to study the structure of the central sequence algebra, by factorizing the
identity map on the central sequence algebra, in a manner resembling the
factorization arising in the definition of nuclear dimension.
  Results about the central sequence algebra are used to attack the conjecture
that finite nuclear dimension implies Z-stability, for sufficiently non-type I,
separable C*-algebras. We prove this conjecture in the following cases: (i) the
C*-algebra has no purely infinite subquotients and its primitive ideal space
has a basis of compact open sets, (ii) the C*-algebra has no purely infinite
quotients and its primitive ideal space is Hausdorff. In particular, this
covers C*-algebras with finite decomposition rank and real rank zero. Our
results hold more generally for C*-algebras with locally finite nuclear
dimension which are (M,N)-pure (a regularity condition of the Cuntz semigroup).


title:
Characterization of highly anisotropic three-dimensionally
  nanostructured surfaces

abstract:
  Generalized ellipsometry, a non-destructive optical characterization
technique, is employed to determine geometrical structure parameters and
anisotropic dielectric properties of highly spatially coherent
three-dimensionally nanostructured thin films grown by glancing angle
deposition. The (piecewise) homogeneous biaxial layer model approach is
discussed, which can be universally applied to model the optical response of
sculptured thin films with different geometries and from diverse materials, and
structural parameters as well as effective optical properties of the
nanostructured thin films are obtained. Alternative model approaches for
slanted columnar thin films, anisotropic effective medium approximations based
on the Bruggeman formalism, are presented, which deliver results comparable to
the homogeneous biaxial layer approach and in addition provide film constituent
volume fraction parameters as well as depolarization or shape factors.
Advantages of these ellipsometry models are discussed on the example of metal
slanted columnar thin films, which have been conformally coated with a thin
passivating oxide layer by atomic layer deposition. Furthermore, the
application of an effective medium approximation approach to in-situ growth
monitoring of this anisotropic thin film functionalization process is
presented. It was found that structural parameters determined with the
presented optical model equivalents for slanted columnar thin films agree very
well with scanning electron microscope image estimates.


title: Entanglement Generation Using Discrete Solitons in Coulomb Crystals

abstract:
  Laser cooled and trapped ions can crystallize and feature discrete solitons,
that are nonlinear, topologically-protected configurations of the Coulomb
crystal. Such solitons, as their continuum counterparts, can move within the
crystal, while their discreteness leads to the existence of a gap-separated,
spatially-localized motional mode of oscillation above the spectrum. Suggesting
that these unique properties of discrete solitons can be used for generating
entanglement between different sites of the crystal, we study a detailed
proposal in the context of state-of-the-art experimental techniques. We analyze
the interaction of periodically-driven planar ion crystals with optical forces,
revealing the effects of micromotion in radio-frequency traps inherent to such
structures, as opposed to linear ion chains. The proposed method requires
Doppler cooling of the crystal and sideband cooling of the soliton's localized
modes alone. Since the gap separation of the latter is nearly independent of
the crystal size, this approach could be particularly useful for producing
entanglement and studying system-environment interactions in large, two- and
possibly three-dimensional systems.


title:
Smart business networks and business genetics with a high tech
  communications supplier selection industry case

abstract:
  Despite the emergence of event driven business process management, smart
business networks, social networks, etc. as important research areas in
management, for all the attractiveness of these concepts, two major challenges
remain around their design and the partner selection rules while learning from
interaction events.While smart business networks should provide advantages due
to the quick connect of business partners for selected functions in a process
common to several parties, literature does not provide constructive methods
whereby the selection of temporary partners and functions can be done. Most
discussions only rely solely on human judgment. This paper introduces both
computational geometry, and genetic programming, as systematic methods whereby
to identify, characterize, and then display on a continuing basis from event
monitoring such possible partnerships; such techniques also allow to plan for
their effect on the organizations and thus to carry out selection. The two
methods are being put in the context of emergence theory. Tessellations address
the identification and categorization issues; business maps address the display
and monitoring challenge with the use of Voronoii diagrams. Cellular automata
mimicking living bodies, with genetic algorithms of which parameters are
estimated by learning, address the selection and effect issues. To illustrate
the approach, some experimental results from the sourcing function in a high
tech industry, are discussed; they address the case of how to determine the
selection process for a systems integrator to set up joint ventures with
smaller technology suppliers.


title:
Negative Off-Diagonal Conductivities in a Weakly Coupled Quark Gluon
  Plasma

abstract:
  We calculate the conductivity matrix of a weakly coupled quark-gluon plasma
at the leading-log order. By setting all quark chemical potentials to be
identical, the diagonal conductivities become degenerate and positive, while
the off-diagonal ones become degenerate but negative (or zero when the chemical
potential vanishes). This means a potential gradient of a certain fermion
flavor can drive backward currents of other flavors. A simple explanation is
provided for this seemingly counter intuitive phenomenon. It is speculated that
this phenomenon is generic and most easily measured in cold atom experiments.

categories: hep-ph cond-mat.quant-gas cond-mat.stat-mech hep-lat nucl-th


title: Purely geometric path integral for spin foams

abstract:
  Spin-foams are a proposal for defining the dynamics of loop quantum gravity
via path integral. In order for a path integral to be at least formally
equivalent to the corresponding canonical quantization, at each point in the
space of histories it is important that the integrand have not only the correct
phase -- a topic of recent focus in spin-foams -- but also the correct modulus,
usually referred to as the measure factor. The correct measure factor descends
from the Liouville measure on the reduced phase space, and its calculation is a
task of canonical analysis.
  The covariant formulation of gravity from which spin-foams are derived is the
Plebanski-Holst formulation, in which the basic variables are a Lorentz
connection and a Lorentz-algebra valued two-form, called the Plebanski
two-form. However, in the final spin-foam sum, one sums over only spins and
intertwiners, which label eigenstates of the Plebanski two-form alone. The
spin-foam sum is therefore a discretized version of a Plebanski-Holst path
integral in which only the Plebanski two-form appears, and in which the
connection degrees of freedom have been integrated out. We call this a purely
geometric Plebanski-Holst path integral.
  In prior work in which one of the authors was involved, the measure factor
for the Plebanski-Holst path integral with both connection and two-form
variables was calculated. Before one discretizes this measure and incorporates
it into a spin-foam sum, however, one must integrate out the connection in
order to obtain the purely geometric version of the path integral. To calculate
this purely geometric path integral is the principal task of the present paper,
and it is done in two independent ways. Gauge-fixing and the background
independence of the resulting path integral are discussed in the appendices.


title:
How and why communications industry suppliers get squeezed out: now, and
  the next phase

abstract:
  The communications systems, terminals, software and deployment service,
industries, have undergone the past ten years a significant technological
internal evolution and external revolution at customer end (such as Internet,
Mobile networks and terminals, Broadband,..). Very little management research
has studied their financial survivability irrespective of changes in demand
volumes in the present technological /organizational cycle. This paper analyzes
the implications of genuine open mandated communications standards, of higher
product volumes, of very high R&D, of the larger use of sourced /purchased
technologies, and of contract manufacturing. The methodology used is
equilibrium analyses. Two specific areas will be mentioned as examples. The
paper also shows how eventually those industries in a later cycle will bounce
back.


title:
Some integral inequalities of Hermite-Hadamard type for functions whose
  derivatives of $n$-th order are $(\alpha,m)$-convex

abstract:
  In the paper, the authors find some new integral inequalities of
Hermite-Hadamard type for functions whose derivatives of the $n$-th order are
$(\alpha,m)$-convex and deduce some known results. As applications of the
newly-established results, the authors also derive some inequalities involving
special means of two positive real numbers.


title:
Strain effects on the electronic structure of the FeSe0.5Te0.5
  superconductor

abstract:
  The electronic structure of the strained FeSe0.5Te0.5 superconductor has been
investigated from first principles. Our calculation results indicate that the
influence of hydrostatic, biaxial or uniaxial compressive stress on the density
of states at the Fermi level is insignificant. The overall shape of the
Fermi-surface (FS) nesting function for FeSe0.5Te0.5 at ambient pressure
resembles that of its parent compound, FeSe, but under the ab-plane compressive
strain. In these two systems, changes of their FSs under various stress
conditions are qualitatively almost the same. However, in FeSe0.5Te0.5 the
intensity of the perfect Q=(0.5,0.5)*(2\pi/a) nesting vector is more
diminished. These findings are in good agreement with former experimental data
and support the idea of spin-fluctuation mediated superconductivity in iron
chalcogenides.


title:
BlueSky: Realizing Buried Potential of Bluetooth to Sustain a
  Large-scale Multi-hop Network

abstract:
  Traditionally, Bluetooth has been deemed unsuitable for sustaining a
large-scale multi-hop network. There are two main reasons: severe frequency
channel collisions under a large-scale network and high complexity of designing
an efficient formation protocol. In this work, we reconsider this viewpoint
from a practical usability perspective and aim to realize the buried potential
of Bluetooth. Firstly, we find that the collision probability under a
low-overhead network is fairly small, which is acceptable for practical
applications. Secondly, we propose BlueSky, a complete system solution to
provide necessary networking functionalities for Bluetooth. In BlueSky, we
develop a connection maintenance mechanism for mitigating the influence of
collisions and a network formation protocol for reliable packet transmissions.
We implement BlueSky on Windows Mobile using 100 commercial smartphones.
Comprehensive usability evaluations demonstrate the negligible overheads of
BlueSky and its good network performance. In particular, 90%-95% of the whole
100 nodes can participate in the communication smoothly.


title:
Comment on "Parametric amplification in Josephson junction embedded
  transmission lines"

abstract:
  Recently Yaakobi and co-workers [Phys. Rev. B 87, 144301 (2013)]
theoretically studied four-wave mixing and parametric amplification in a
nonlinear transmission line consisting of capacitively shunted Josephson
junctions. By deriving and solving the coupled-mode equations, they have
arrived at the conclusion that in a wide frequency range around the pump
frequency exponential parametric gain (in which the signal grows exponentially
with distance) can be achieved. However, we have found a mathematical error in
their derivation of the coupled-mode equations (Equation (A13)), which leads to
the wrong expression of the gain factor and invalidates their conclusions on
the gain and bandwidth. In this comment, we present the correct expression for
the parametric gain. We show that for a transmission line with weak dispersion
or positive dispersion ($\Delta k>0 $), as is the case discussed by Yaakobi et
al, while quadratic (power) gain can occur around the pump frequency,
exponential gain is impossible. Furthermore, for a transmission line with
proper intrinsic or engineered dispersion, exponential gain occurs at
frequencies where the phase matching condition is met, while around the pump
frequency the gain is still quadratic.


title: Subadditivity of Matrix phi-Entropy and Concentration of Random Matrices

abstract:
  Matrix concentration inequalities provide a direct way to bound the typical
spectral norm of a random matrix. The methods for establishing these results
often parallel classical arguments, such as the Laplace transform method. This
work develops a matrix extension of the entropy method, and it applies these
ideas to obtain some matrix concentration inequalities.


title: Protein folding tames chaos

abstract:
  Protein folding produces characteristic and functional three-dimensional
structures from unfolded polypeptides or disordered coils. The emergence of
extraordinary complexity in the protein folding process poses astonishing
challenges to theoretical modeling and computer simulations. The present work
introduces molecular nonlinear dynamics (MND), or molecular chaotic dynamics,
as a theoretical framework for describing and analyzing protein folding. We
unveil the existence of intrinsically low dimensional manifolds (ILDMs) in the
chaotic dynamics of folded proteins. Additionally, we reveal that the
transition from disordered to ordered conformations in protein folding
increases the transverse stability of the ILDM. Stated differently, protein
folding reduces the chaoticity of the nonlinear dynamical system, and a folded
protein has the best ability to tame chaos. Additionally, we bring to light the
connection between the ILDM stability and the thermodynamic stability, which
enables us to quantify the disorderliness and relative energies of folded,
misfolded and unfolded protein states. Finally, we exploit chaos for protein
flexibility analysis and develop a robust chaotic algorithm for the prediction
of Debye-Waller factors, or temperature factors, of protein structures.


title: Trace Complexity of Network Inference

abstract:
  The network inference problem consists of reconstructing the edge set of a
network given traces representing the chronology of infection times as
epidemics spread through the network. This problem is a paradigmatic
representative of prediction tasks in machine learning that require deducing a
latent structure from observed patterns of activity in a network, which often
require an unrealistically large number of resources (e.g., amount of available
data, or computational time). A fundamental question is to understand which
properties we can predict with a reasonable degree of accuracy with the
available resources, and which we cannot. We define the trace complexity as the
number of distinct traces required to achieve high fidelity in reconstructing
the topology of the unobserved network or, more generally, some of its
properties. We give algorithms that are competitive with, while being simpler
and more efficient than, existing network inference approaches. Moreover, we
prove that our algorithms are nearly optimal, by proving an
information-theoretic lower bound on the number of traces that an optimal
inference algorithm requires for performing this task in the general case.
Given these strong lower bounds, we turn our attention to special cases, such
as trees and bounded-degree graphs, and to property recovery tasks, such as
reconstructing the degree distribution without inferring the network. We show
that these problems require a much smaller (and more realistic) number of
traces, making them potentially solvable in practice.


title: Community Detection in Sparse Random Networks

abstract:
  We consider the problem of detecting a tight community in a sparse random
network. This is formalized as testing for the existence of a dense random
subgraph in a random graph. Under the null hypothesis, the graph is a
realization of an Erd\"os-R\'enyi graph on $N$ vertices and with connection
probability $p_0$; under the alternative, there is an unknown subgraph on $n$
vertices where the connection probability is p1 > p0. In Arias-Castro and
Verzelen (2012), we focused on the asymptotically dense regime where p0 is
large enough that np0>(n/N)^{o(1)}. We consider here the asymptotically sparse
regime where p0 is small enough that np0<(n/N)^{c0} for some c0>0. As before,
we derive information theoretic lower bounds, and also establish the
performance of various tests. Compared to our previous work, the arguments for
the lower bounds are based on the same technology, but are substantially more
technical in the details; also, the methods we study are different: besides a
variant of the scan statistic, we study other statistics such as the size of
the largest connected component, the number of triangles, the eigengap of the
adjacency matrix, etc. Our detection bounds are sharp, except in the Poisson
regime where we were not able to fully characterize the constant arising in the
bound.


title:
Wiener criteria for existence of large solutions of quasilinear elliptic
  equations with absorption

abstract:
  We obtain sufficient conditions expressed in terms of Wiener type tests
involving Hausdorff or Bessel capacities for the existence of large solutions
to equations (1) $-\Gd_pu+e^{\lambda u}+\beta=0$ or (2) $-\Gd_pu+\lambda
|u|^{q-1}u+\beta=0$ in a bounded domain $\Gw$ when $q>p-1>0, \lambda>0$ and
$\beta\in\mathbb{R}$. We apply our results to equations (3)
$-\Gd_pu+a\abs{\nabla u}^{q}+bu^{s}=0$, (4) $\Gd_p u+u^{-\gamma}=0$ with $10,
b\geq 0$ and $(q-p+1)+b(s-p+1)>0$, $\gamma>0$.


title: Over-the-counter market models with several assets

abstract:
  We study two classes of over-the-counter markets specified by systems of
ODE's, in the spirit of Duffie-Garleanu-Pedersen, Econometrica, 2005. We first
compute the steady states for many of these ODE's. Then we obtain the prices at
which investors trade with each other at these steady states. Finally, we study
the stability of the solutions of these ODE's.


title: Gas-phase CO depletion and N2H+ abundances in starless cores

abstract:
  Seven isolated, nearby low-mass starless molecular cloud cores have been
observed as part of the Herschel key program Earliest Phases of Star formation
(EPoS). By applying a ray-tracing technique to the obtained continuum emission
and complementary (sub)mm emission maps, we derive the physical structure
(density, dust temperature) of these cloud cores. We present observations of
the 12CO, 13CO, and C18O (2-1) and N2H+ (1-0) transitions towards the same
cores. Based on the density and temperature profiles, we apply time-dependent
chemical and line-radiative transfer modeling and compare the modeled to the
observed molecular emission profiles. CO is frozen onto the grains in the
center of all cores in our sample. The level of CO depletion increases with
hydrogen density and ranges from 46% up to more than 95% in the core centers in
the core centers in the three cores with the highest hydrogen density. The
average hydrogen density at which 50% of CO is frozen onto the grains is
1.1+-0.4 10^5 cm^-3. At about this density, the cores typically have the
highest relative abundance of N2H+. The cores with higher central densities
show depletion of N2H+ at levels of 13% to 55%. The chemical ages for the
individual species are on average 2+-1 10^5 yr for 13CO, 6+-3 10^4 yr for C18O,
and 9+-2 10^4 yr for N2H+. Chemical modeling indirectly suggests that the gas
and dust temperatures decouple in the envelopes and that the dust grains are
not yet significantly coagulated. We observationally confirm chemical models of
CO-freezeout and nitrogen chemistry. We find clear correlations between the
hydrogen density and CO depletion and the emergence of N2H+. The chemical ages
indicate a core lifetime of less than 1 Myr.


title: Modular Properties of 3D Higher Spin Theory

abstract:
  In the three-dimensional sl(N) Chern-Simons higher-spin theory, we prove that
the conical surplus and the black hole solution are related by the
S-transformation of the modulus of the boundary torus. Then applying the
modular group on a given conical surplus solution, we generate a 'SL(2,Z)'
family of smooth constant solutions. We then show how these solutions are
mapped into one another by coordinate transformations that act non-trivially on
the homology of the boundary torus. After deriving a thermodynamics that
applies to all the solutions in the 'SL(2,Z)' family, we compute their
entropies and free energies, and determine how the latter transform under the
modular transformations. Summing over all the modular images of the conical
surplus, we write down a (tree-level) modular invariant partition function.


title:
Low Dimensional Supersymmetries in SUSY Chern-Simons Systems and
  Geometrical Implications

abstract:
  We study in detail the underlying graded geometric structure of abelian N=2
supersymmetric Chern-Simons theory in $(2+1)$-dimensions. This structure is an
attribute of the hidden unbroken one dimensional N=2 supersymmetries that the
system also possesses. We establish the result that the geometric structures
corresponding to the bosonic and to the fermionic sectors are equivalent fibre
bundles over the $(2+1)$-dimensional manifold. Moreover, we find a geometrical
answer to the question why some and not all of the fermionic sections are
related to a N=2 supersymmetric algebra. Our findings are useful for the
quantum theory of Chern-Simons vortices.


title: The $q$-log-convexity of Domb's polynomials

abstract:
  In this paper, we prove the $q$-log-convexity of Domb's polynomials, which
was conjectured by Sun in the study of Ramanujan-Sato type series for powers of
$\pi$. As a result, we obtain the log-convexity of Domb's numbers. Our proof is
based on the $q$-log-convexity of Narayana polynomials of type $B$ and a
criterion for determining $q$-log-convexity of self-reciprocal polynomials.


title:
Locally Rotationally Symmetric Bianchi Type-I cosmological model in
  $f(T)$ gravity: from early to Dark Energy dominated universe

abstract:
  We study the locally rotational symmetry Bianchi type-I dark energy model in
the framework of $f(T)$ theory of gravity, where $T$ denotes the torsion
scalar. A viable cosmological model is undertaken and the isotropization of
this latter is checked, yielding a result that reflects the real evolution of
our universe. Moreover, still in the anisotropic optic, a more complicated
$f(T)$ model is obtained from the cosmological reconstruction scheme and the
analysis shows that the universe is more anisotropic at the beginning if the
terms of higher order in $T$ are not considered. This means that the non-linear
model should be favoured by observational data.


title:
Water Absorption from Gas Very Near the Massive Protostar AFGL 2136 IRS
  1

abstract:
  We present ground-based observations of the nu_1 and nu_3 fundamental bands
of H2O toward the massive protostar AFGL 2136 IRS 1, identifying absorption
features due to 47 different ro-vibrational transitions between 2.468 micron
and 2.561 micron. Analysis of these features indicates the absorption arises in
warm (T=506+-25 K), very dense (n(H2)>5*10^9 cm^-3) gas, suggesting an origin
close to the central protostar. The total column density of warm water is
estimated to be N(H2O)=(1.02+-0.02)*10^19 cm^-2, giving a relative abundance of
N(H2O)/N(H2)~10^-4. Our study represents the first extensive use of water vapor
absorption lines in the near infrared, and demonstrates the utility of such
observations in deriving physical parameters.


title:
The Formation of Eccentric Compact Binary Inspirals and the Role of
  Gravitational Wave Emission in Binary-Single Stellar Encounters

abstract:
  The inspiral and merger of eccentric binaries leads to gravitational
waveforms distinct from those generated by circularly merging binaries.
Dynamical environments can assemble binaries with high eccentricity and peak
frequencies within the {\it LIGO} band. In this paper, we study binary-single
stellar scatterings occurring in dense stellar systems as a source of
eccentrically-inspiraling binaries. Many interactions between compact binaries
and single objects are characterized by chaotic resonances in which the
binary-single system undergoes many exchanges before reaching a final state.
During these chaotic resonances, a pair of objects has a non-negligible
probability of experiencing a very close passage. Significant orbital energy
and angular momentum are carried away from the system by gravitational wave
(GW) radiation in these close passages and in some cases this implies an
inspiral time shorter than the orbital period of the bound third body. We
derive the cross section for such dynamical inspiral outcomes through
analytical arguments and through numerical scattering experiments including GW
losses. We show that the cross section for dynamical inspirals grows with
increasing target binary semi-major axis, $a$, and that for equal-mass binaries
it scales as $a^{2/7}$. Thus, we expect wide target binaries to predominantly
contribute to the production of these relativistic outcomes. We estimate that
eccentric inspirals account for approximately one percent of dynamically
assembled non-eccentric merging binaries. While these events are rare, we show
that binary-single scatterings are a more effective formation channel than
single-single captures for the production of eccentrically-inspiraling
binaries, even given modest binary fractions.


title:
GYRE: An open-source stellar oscillation code based on a new Magnus
  Multiple Shooting Scheme

abstract:
  We present a new oscillation code, GYRE, which solves the stellar pulsation
equations (both adiabatic and non-adiabatic) using a novel Magnus Multiple
Shooting numerical scheme devised to overcome certain weaknesses of the usual
relaxation and shooting schemes appearing in the literature. The code is
accurate (up to 6th order in the number of grid points), robust, efficiently
makes use of multiple processor cores and/or nodes, and is freely available in
source form for use and distribution. We verify the code against analytic
solutions and results from other oscillation codes, in all cases finding good
agreement. Then, we use the code to explore how the asteroseismic observables
of a 1.5 M_sun star change as it evolves through the red-giant bump.


title: Survival of molecular gas in cavities of transition disks (I. CO)

abstract:
  (Abridged) Planet formation is closely related to the structure and dispersal
of protoplanetary disks. A certain class of disks, called transition disks,
exhibit cavities in dust images at scales of up to a few 10s of AU. The
formation mechanism of the cavities is still unclear. The gas content of such
cavities can be spatially resolved for the first time using the Atacama Large
Millimeter/submillimeter Array (ALMA).
  We have developed a new series of models to simulate the physical conditions
and chemical abundances of the gas in cavities to address the question whether
the gas is primarily atomic or molecular inside the dust free cavities exposed
to intense UV radiation. Molecular/atomic line emission by carbon monoxide
(CO), its isotopologues (13CO, C18O, C17O, and 13C18O) and related species
([CI], [CII], and [OI]) is predicted for comparison with ALMA and the Herschel
Space Observatory.
  The gas can remain in molecular form down to very low amounts of gas in the
cavity. Shielding of the stellar radiation by a dusty inner disk
(pre-transition disk) allows CO to survive down to lower gas masses in the
cavity. The main parameter for the CO emission from cavity is the gas mass.
Other parameters such as the outer disk mass, bolometric luminosity, shape of
the stellar spectrum or PAH abundance are less important. Since the CO pure
rotational lines readily become optically thick, the CO isotopologues need to
be observed in order to quantitatively determine the amount of gas in the
cavity.
  A wide range of gas masses in the cavity of transition disks (~4 orders of
magnitude) can be probed using combined observations of CO isotopologue lines
with ALMA. Measuring the gas mass in the cavity will ultimately help to
distinguish between different cavity formation theories.


title:
New X-ray Selected Pre-Main Sequence Members of the Serpens Molecular
  Cloud

abstract:
  The study of young stars no longer surrounded by disks can greatly add to our
understanding of how protoplanetary disks evolve and planets form. We have used
VLT/FLAMES optical spectroscopy to confirm the youth and membership of 19 new
young diskless stars in the Serpens Molecular Cloud, identified at X-ray
wavelengths. Spectral types, effective temperatures and stellar luminosities
were determined using the optical spectra and optical/near-IR photometry.
Stellar masses and ages were derived based on PMS evolutionary tracks. The
results yield remarkable similarities for age and mass distribution between the
diskless and disk-bearing stellar populations in Serpens. We discuss the
important impli- cations these similarities may have on the standard picture of
disk evolution.


title:
High-Temperature Processing of Solids Through Solar Nebular Bow Shocks:
  3D Radiation Hydrodynamics Simulations with Particles

abstract:
  A fundamental, unsolved problem in Solar System formation is explaining the
melting and crystallization of chondrules found in chondritic meteorites.
Theoretical models of chondrule melting in nebular shocks has been shown to be
consistent with many aspects of thermal histories inferred for chondrules from
laboratory experiments; but, the mechanism driving these shocks is unknown.
Planetesimals and planetary embryos on eccentric orbits can produce bow shocks
as they move supersonically through the disk gas, and are one possible source
of chondrule-melting shocks. We investigate chondrule formation in bow shocks
around planetoids through 3D radiation hydrodynamics simulations. A new
radiation transport algorithm that combines elements of flux-limited diffusion
and Monte Carlo methods is used to capture the complexity of radiative
transport around bow shocks. An equation of state that includes the rotational,
vibrational, and dissociation modes of H$_2$ is also used. Solids are followed
directly in the simulations and their thermal histories are recorded. Adiabatic
expansion creates rapid cooling of the gas, and tail shocks behind the embryo
can cause secondary heating events. Radiative transport is efficient, and bow
shocks around planetoids can have luminosities $\sim$few$\times10^{-8}$
L$_{\odot}$. While barred and radial chondrule textures could be produced in
the radiative shocks explored here, porphyritic chondrules may only be possible
in the adiabatic limit. We present a series of predicted cooling curves that
merit investigation in laboratory experiments to determine whether the solids
produced by bow shocks are represented in the meteoritic record by chondrules
or other solids.


title: A phase transition between the niche and neutral regimes in ecology

abstract:
  An ongoing debate in ecology concerns the impacts of ecological drift and
selection on community assembly. Here, we show that there is a sharp phase
transition in diverse ecological communities between a selection dominated
regime (the niche phase) and a drift dominated regime (the neutral phase).
Simulations and analytic arguments show that the niche phase is favored in
communities with large population sizes and relatively constant environments,
whereas the neutral phase is favored in communities with small population sizes
and fluctuating environments. Our results demonstrate how apparently neutral
populations may arise even in communities inhabited by species with varying
traits.


title: Gap Theorems for the Delay of Circuits Simulating Finite Automata

abstract:
  We study the delay (also known as depth) of circuits that simulate finite
automata, showing that only certain growth rates (as a function of the number
$n$ of steps simulated) are possible. A classic result due to Ofman
(rediscovered and popularized by Ladner and Fischer) says that delay $O(\log
n)$ is always sufficient. We show that if the automaton is "generalized
definite", then delay O(1) is sufficient, but otherwise delay $\Omega(\log n)$
is necessary; there are no intermediate growth rates. We also consider
"physical" (rather than "logical") delay, whereby we consider the lengths of
wires when inputs and outputs are laid out along a line. In this case, delay
O(n) is clearly always sufficient. We show that if the automaton is "definite",
then delay O(1) is sufficient, but otherwise delay $\Omega(n)$ is necessary;
again there are no intermediate growth rates. Inspired by an observation of
Burks, Goldstein and von Neumann concerning the average delay due to carry
propagation in ripple-carry adders, we derive conditions for the average
physical delay to be reduced from O(n) to $O(\log n)$, or to O(1), when the
inputs are independent and uniformly distributed random variables; again there
are no intermediate growth rates. Finally we consider an extension of this last
result to a situation in which the inputs are not independent and uniformly
distributed, but rather are produced by a non-stationary Markov process, and in
which the computation is not performed by a single automaton, but rather by a
sequence of automata acting in alternating directions.


title: A Compact Spectrograph to Search for Extrasolar Planets

abstract:
  The most successful method used so far to search for extrasolar planets is
the radial velocity technique, where periodical shifts on the measured emission
from a star provide evidence for an orbiting planet. This method has been used
on large telescopes with large and expensive instrumentation, only enabling a
small amount of observing time per star. We have developed a compact
spectrograph fed by one or several single-mode fibres that avoids the need for
complex fibre scrambling or gas absorption cells for calibration. In principle,
this will enable planet searches around bright stars over the next few years.
We aim to pave the way for large networks of small telescopes searching for
Earth-like planets. At a resolving power of R~50000, I have characterized this
spectrograph, determined its stability and the fidelity required for a
simultaneous calibration source.


title: Quotient polynomials with positive coefficients

abstract:
  We give an optimal necessary and sufficient condition for the quotient
polynomial and remainder in the division algorithm to have positive
coefficients.


title: Heavy-flavour and quarkonia in heavy-ion collisions

abstract:
  The comparison of heavy-flavour hadron production in proton-proton, proton-Pb
and Pb-Pb collisions at the LHC offers the opportunity to investigate the
properties of the high-density colour-deconfined state of strongly-interacting
matter (Quark Gluon Plasma, QGP) that is expected to be formed in high-energy
collisions of heavy nuclei. A review of the main quarkonium and open
heavy-flavour results obtained by the ALICE, ATLAS and CMS experiments is
presented.


title:
Evolution of the Stellar-to-Dark Matter Relation: Separating
  Star-Forming and Passive Galaxies from z=1 to 0

abstract:
  We use measurements of the stellar mass function, galaxy clustering, and
galaxy-galaxy lensing within the COSMOS survey to constrain the stellar-to-halo
mass relation (SHMR) of star forming and quiescent galaxies over the redshift
range z=[0.2,1.0]. For massive galaxies, M*>~10^10.6 Msol, our results indicate
that star-forming galaxies grow proportionately as fast as their dark matter
halos while quiescent galaxies are outpaced by dark matter growth. At lower
masses, there is minimal difference in the SHMRs, implying that the majority
low-mass quiescent galaxies have only recently been quenched of their star
formation. Our analysis also affords a breakdown of all COSMOS galaxies into
the relative numbers of central and satellite galaxies for both populations. At
z=1, satellite galaxies dominate the red sequence below the knee in the stellar
mass function. But the number of quiescent satellites exhibits minimal redshift
evolution; all evolution in the red sequence is due to low-mass central
galaxies being quenched of their star formation. At M*~10^10 Msol, the fraction
of central galaxies on the red sequence increases by a factor of ten over our
redshift baseline, while the fraction of quenched satellite galaxies at that
mass is constant with redshift. We define a "migration rate" to the red
sequence as the time derivative of the passive galaxy abundances. We find that
the migration rate of central galaxies to the red sequence increases by nearly
an order of magnitude from z=1 to z=0. These results imply that the efficiency
of quenching star formation for centrals is increasing with cosmic time, while
the mechanisms that quench the star formation of satellite galaxies in groups
and clusters is losing efficiency.