title:
Relativistic Energy Analysis Of Five Dimensional q-Deformed Radial
  Rosen-Morse Potential Combined With q-Deformed Trigonometric Scarf
  Non-Central Potential Using Asymptotic Iteration Method (AIM)

abstract:
  In this work, we study the exact solution of Dirac equation in the
hyper-spherical coordinate under influence of separable q-Deformed quantum
potentials. The q-deformed hyperbolic Rosen-Morse potential is perturbed by
q-deformed non-central trigonometric Scarf potentials, where whole of them can
be solved by using Asymptotic Iteration Method (AIM). This work is limited to
spin symmetry case. The relativistic energy equation and orbital quantum number
equation lD-1 have been obtained using Asymptotic Iteration Method. The upper
radial wave function equations and angular wave function equations are also
obtained by using this method. The relativistic energy levels are numerically
calculated using Mat Lab, the increase of radial quantum number n causes the
increase of bound state relativistic energy level both in dimension D = 5 and D
= 3. The bound state relativistic energy level decreases with increasing of
both deformation parameter q and orbital quantum number nl.


title:
General scheme for stable single and multiatom nanomagnets according to
  symmetry selection rules

abstract:
  At low temperature, information can be stored in the orientation of the
localized magnetic moment of an adatom. However, scattering of electrons and
phonons with the nanomagnet leads its state to have incoherent classical
dynamics and might cause fast loss of the encoded information. Recently, it has
been understood that such scattering obeys certain selection rules due to the
symmetries of the system. By analyzing the point-group symmetry of the surface,
the time-reversal symmetry and the magnitude of the adatom effective spin, we
identify which nanomagnets configurations are to be avoided and which are
promising to encode a stable bit. A new tool of investigation is introduced and
exploited: the quasi-spin quantum number. By means of this tool, our results
are easily generalized to a broad class of bipartite cluster configurations
where adatoms are coupled through Heisenberg-like interactions. Finally, to
make contact with the experiments, numerical simulations have been performed to
show how such stable configurations respond to typical scanning tunneling
microscopy measurements.


title: Certain irreducible characters over a normal subgroup

abstract:
  We extend the Howlett-Isaacs theorem on the solvability of groups of central
type taking into account actions by automorphisms. Then we study certain
induced characters whose constituents have all the same degree.


title: On Robust Colorings of Hamming-Distance Graphs

abstract:
  $H_q(n,d)$ is defined as the graph with vertex set ${\mathbb Z}_q^n$ and
where two vertices are adjacent if their Hamming distance is at least $d$. The
chromatic number of these graphs is presented for various sets of parameters
$(q,n,d)$. For the $4$-colorings of the graphs $H_2(n,n-1)$ a notion of
robustness is introduced. It is based on the tolerance of swapping colors along
an edge without destroying properness of the coloring. An explicit description
of the maximally robust $4$-colorings of $H_2(n,n-1)$ is presented.


title: Local average height distribution of fluctuating interfaces

abstract:
  Height fluctuations of growing surfaces can be characterized by the
probability distribution of height in a spatial point at a finite time.
Recently there has been spectacular progress in the studies of this quantity
for the Kardar-Parisi-Zhang (KPZ) equation in $1+1$ dimensions. Here we notice
that, at or above a critical dimension, the finite-time one-point height
distribution is ill-defined in a broad class of linear surface growth models,
unless the model is regularized at small scales. The regularization via a
system-dependent small-scale cutoff leads to a partial loss of universality. As
a possible alternative, we introduce a \emph{local average height}. For the
linear models the probability density of this quantity is well-defined in any
dimension. The weak-noise theory (WNT) for these models yields the "optimal
path" of the interface conditioned on a non-equilibrium fluctuation of the
local average height. As an illustration, we consider the conserved
Edwards-Wilkinson (EW) equation, where, without regularization, the finite-time
one-point height distribution is ill-defined in all physical dimensions. We
also determine the optimal path of the interface in a closely related problem
of the finite-time \emph{height-difference} distribution for the non-conserved
EW equation in $1+1$ dimension. Finally, we discuss a UV catastrophe in the
finite-time one-point distribution of height in the (non-regularized) KPZ
equation in $2+1$ dimensions.


title: Testing $k$-Monotonicity

abstract:
  A Boolean $k$-monotone function defined over a finite poset domain ${\cal D}$
alternates between the values $0$ and $1$ at most $k$ times on any ascending
chain in ${\cal D}$. Therefore, $k$-monotone functions are natural
generalizations of the classical monotone functions, which are the $1$-monotone
functions. Motivated by the recent interest in $k$-monotone functions in the
context of circuit complexity and learning theory, and by the central role that
monotonicity testing plays in the context of property testing, we initiate a
systematic study of $k$-monotone functions, in the property testing model. In
this model, the goal is to distinguish functions that are $k$-monotone (or are
close to being $k$-monotone) from functions that are far from being
$k$-monotone. Our results include the following:
  - We demonstrate a separation between testing $k$-monotonicity and testing
monotonicity, on the hypercube domain $\{0,1\}^d$, for $k\geq 3$;
  - We demonstrate a separation between testing and learning on $\{0,1\}^d$,
for $k=\omega(\log d)$: testing $k$-monotonicity can be performed with
$2^{O(\sqrt d \cdot \log d\cdot \log{1/\varepsilon})}$ queries, while learning
$k$-monotone functions requires $2^{\Omega(k\cdot \sqrt
d\cdot{1/\varepsilon})}$ queries (Blais et al. (RANDOM 2015)).
  - We present a tolerant test for functions $f\colon[n]^d\to \{0,1\}$ with
complexity independent of $n$, which makes progress on a problem left open by
Berman et al. (STOC 2014).
  Our techniques exploit the testing-by-learning paradigm, use novel
applications of Fourier analysis on the grid $[n]^d$, and draw connections to
distribution testing techniques.


title: Retrofitting Applications with Provenance-Based Security Monitoring

abstract:
  Data provenance is a valuable tool for detecting and preventing cyber attack,
providing insight into the nature of suspicious events. For example, an
administrator can use provenance to identify the perpetrator of a data leak,
track an attacker's actions following an intrusion, or even control the flow of
outbound data within an organization. Unfortunately, providing relevant data
provenance for complex, heterogenous software deployments is challenging,
requiring both the tedious instrumentation of many application components as
well as a unified architecture for aggregating information between components.
  In this work, we present a composition of techniques for bringing affordable
and holistic provenance capabilities to complex application workflows, with
particular consideration for the exemplar domain of web services. We present
DAP, a transparent architecture for capturing detailed data provenance for web
service components. Our approach leverages a key insight that minimal knowledge
of open protocols can be leveraged to extract precise and efficient provenance
information by interposing on application components' communications, granting
DAP compatibility with existing web services without requiring instrumentation
or developer cooperation. We show how our system can be used in real time to
monitor system intrusions or detect data exfiltration attacks while imposing
less than 5.1 ms end-to-end overhead on web requests. Through the introduction
of a garbage collection optimization, DAP is able to monitor system activity
without suffering from excessive storage overhead. DAP thus serves not only as
a provenance-aware web framework, but as a case study in the non-invasive
deployment of provenance capabilities for complex applications workflows.


title: Micromachining structured optical fibers using focused ion beam milling

abstract:
  A focused ion beam is used to mill side holes in air-silica structured
fibres. By way of example, side holes are introduced in two types of
air-structured fibres (1) a photonic crystal four-ring fibre and (2) a 6-hole
single ring step index structured fibre.


title: Random graph approach to multifunctional molecular networks

abstract:
  Formation of a molecular network from multifunctional precursors is modelled
with a random graph process. The random graph model favours reactivity for
monomers that are positioned close in the network topology, and disfavours
reactivity for those that are obscured by the surrounding. The phenomena of
conversion-dependant reaction rates, gelation, and micro-gelation are thus
naturally predicted by the model and do not have to be imposed. Resulting
non-homogeneous network topologies are analysed to extract such descriptors as:
size distribution, crosslink distances, and gel-point conversion. Furthermore,
new to the molecular simulation community descriptors are invented. These
descriptors are especially useful for understanding evolution of pure gel,
amongst them: cluster coefficient, network modularity, cluster size
distribution.


title:
Analytic Evaluation of some 2-, 3- and 4- Electron Atomic Integrals
  Containing Exponentially Correlated Functions of $r_{ij}$

abstract:
  A simple method is outlined for analytic evaluation of the basic 2-electron
atomic integral with integrand containing products of atomic s-type Slater
orbitals and exponentially correlated function of the form $r_{ij}
exp(-\lambda_{ij}r_{ij})$, by employing the Fourier representation of
$exp(-\lambda_{ij}r_{ij})/r_{ij}$ without the use of either the spherical
harmonic addition theorem or the Feynman technique. This method is applied to
obtain closed-form expressions, in a simple manner, for certain other 2-,3- and
4-electron atomic integrals with integrands which are products of exponentially
correlated functions and atomic s-type Slater orbitals.


title:
On the effect of the cosmological expansion on the gravitational lensing
  by a point mass

abstract:
  We analyze the effect of the cosmological expansion on the deflection of
light caused by a point mass, adopting the McVittie metric as the geometrical
description of a pointlike lens embedded in an expanding universe. In the case
of a generic, non-constant Hubble parameter $H$ we derive and approximately
solve the null geodesic equations, finding an expression for the bending angle
$\delta$, which we expand in powers of the mass-to-closest approach distance
ratio and of the impact parameter-to-lens distance ratio. It turns out that the
leading order of the aforementioned expansion is the same as the one calculated
for the Schawarzschild metric and that cosmological corrections contribute to
$\delta$ only at sub-dominant orders. We explicitly calculate these
cosmological corrections for the case of $H$ constant and find that they
provide a correction of order $10^{-11}$ on the lens mass estimate.


title: On structure and TKK algebras for Jordan superalgebras

abstract:
  We compare a number of different definitions of structure algebras and TKK
constructions for Jordan (super)algebras appearing in the literature. We
demonstrate that, for unital superalgebras, all the definitions of the
structure algebra and the TKK constructions fall apart into two cases.
Moreover, one can be obtained as the Lie superalgebra of superderivations of
the other. We also show that, for non-unital superalgebras, more definitions
become non-equivalent. As an application, we obtain the corresponding Lie
superalgebras for all simple finite dimensional Jordan superalgebras over an
algebraically closed field of characteristic zero.


title:
Competing quantum effects in the free energy profiles and diffusion
  rates of hydrogen and deuterium molecules through clathrate hydrates

abstract:
  Clathrate hydrates hold considerable promise as safe and economical materials
for hydrogen storage. Here we present a quantum mechanical study of H$_2$ and
D$_2$ diffusion through a hexagonal face shared by two large cages of clathrate
hydrates over a wide range of temperatures. Path integral molecular dynamics
simulations are used to compute the free-energy profiles for the diffusion of
H$_2$ and D$_2$ as a function of temperature. Ring polymer molecular dynamics
rate theory, incorporating both exact quantum statistics and approximate
quantum dynamical effects, is utilized in the calculations of the H$_2$ and
D$_2$ diffusion rates in a broad temperature interval. We find that the shape
of the quantum free-energy profiles and their height relative to the classical
free energy barriers at a given temperature, as well as the rate of diffusion,
are profoundly affected by competing quantum effects: above 25 K, zero-point
energy (ZPE) perpendicular to the reaction path for diffusion between cavities
decreases the quantum rate compared to the classical rate, whereas at lower
temperatures tunneling outcompetes the ZPE and as result the quantum rate is
greater than the classical rate.


title:
The multipolar magnetic fields of accreting pre-main-sequence stars: B
  at the inner disk, B along the accretion flow, and B at the accretion shock

abstract:
  Zeeman-Doppler imaging studies have revealed the complexity of the
large-scale magnetic fields of accreting pre-main-sequence stars. All have
multipolar magnetic fields with the octupole component being the dominant field
mode for many of the stars studied thusfar. Young accreting stars with fully
convective interiors often feature simple axisymmetric magnetic fields with
dipole components of order a kilo-Gauss (at least those of mass
$\gtrsim0.5\,{\rm M}_\odot$), while those with substantially radiative
interiors host more complex non-axisymmetric magnetic fields with dipole
components of order a few 0.1 kilo-Gauss. Here, via several simple examples, we
demonstrate that i). in most cases, the dipole component alone can be used to
estimate the disk truncation radius (but little else); ii) due the presence of
higher order magnetic field components, the field strength in the accretion
spots is far in excess of that expected if a pure dipole magnetic field is
assumed. (Fields of $\sim$6$\,{\rm kG}$ have been measured in accretion
spots.); iii) if such high field strengths are taken to be representative of
the polar strength of a dipole magnetic field, the disk truncation radius would
be overestimated. The effects of multipolar magnetic fields must be considered
in both models of accretion flow and of accretion shocks.


title: Preduals of JBW$^*$-triples are 1-Plichko spaces

abstract:
  We prove that the predual, $M_*$, of a JBW$^*$-triple $M$ is a 1-Plichko
space (i.e. it admits a countably 1-norming Markushevich basis or,
equivalently, it has a commutative 1-projectional skeleton), and obtain a
natural description of the $\Sigma$-subspace of $M$. This generalizes and
improves similar results for von Neumann algebras and JBW$^*$-algebras.
Consequently, dual spaces of JB$^*$-triples also are 1-Plichko spaces. We also
show that $M_*$ is weakly Lindel\"{o}f determined if and only if $M$ is
$\sigma$-finite if and only if $M_*$ is weakly compactly generated. Moreover,
contrary to the proof for JBW$^*$-algebras, our proof dispenses with the use of
elementary submodels theory.


title:
Dusty tails of evaporating exoplanets. II. Physical modelling of the KIC
  12557548b light curve

abstract:
  Evaporating rocky exoplanets, such as KIC 12557548b, eject large amounts of
dust grains, which can trail the planet in a comet-like tail. When such objects
occult their host star, the resulting transit signal contains information about
the dust in the tail. We aim to use the detailed shape of the Kepler light
curve of KIC 12557548b to constrain the size and composition of the dust grains
that make up the tail, as well as the mass loss rate of the planet. Using a
self-consistent numerical model of the dust dynamics and sublimation, we
calculate the shape of the tail by following dust grains from their ejection
from the planet to their destruction due to sublimation. From this dust cloud
shape, we generate synthetic light curves (incorporating the effects of
extinction and angle-dependent scattering), which are then compared with the
phase-folded Kepler light curve. We explore the free-parameter space thoroughly
using a Markov chain Monte Carlo method. Our physics-based model is capable of
reproducing the observed light curve in detail. Good fits are found for initial
grain sizes between 0.2 and 5.6 micron and dust mass loss rates of 0.6 to 15.6
M_earth/Gyr (2-sigma ranges). We find that only certain combinations of
material parameters yield the correct tail length. These constraints are
consistent with dust made of corundum (Al2O3), but do not agree with a range of
carbonaceous, silicate, or iron compositions. Using a detailed, physically
motivated model, it is possible to constrain the composition of the dust in the
tails of evaporating rocky exoplanets. This provides a unique opportunity to
probe to interior composition of the smallest known exoplanets.


title: A simple assessment on inflation

abstract:
  We consider the torsional completion of gravity with spinor and scalar
fields: we show how in this environment conditions of extreme symmetry or
specific approximations imply the scalar field to be constant, so that
slow-roll takes place and inflation occurs.


title: Relationalism about mechanics based on a minimalist ontology of matter

abstract:
  This paper elaborates on relationalism about space and time as motivated by a
minimalist ontology of the physical world: there are only matter points that
are individuated by the distance relations among them, with these relations
changing. We assess two strategies to combine this ontology with physics, using
classical mechanics as example: the Humean strategy adopts the standard,
non-relationalist physical theories as they stand and interprets their formal
apparatus as the means of bookkeeping of the change of the distance relations
instead of committing us to additional elements of the ontology. The
alternative theory strategy seeks to combine the relationalist ontology with a
relationalist physical theory that reproduces the predictions of the standard
theory in the domain where these are empirically tested. We show that, as
things stand, this strategy cannot be accomplished without compromising a
minimalist relationalist ontology.


title: Semantic Image Based Geolocation Given a Map

abstract:
  The problem visual place recognition is commonly used strategy for
localization. Most successful appearance based methods typically rely on a
large database of views endowed with local or global image descriptors and
strive to retrieve the views of the same location. The quality of the results
is often affected by the density of the reference views and the robustness of
the image representation with respect to viewpoint variations, clutter and
seasonal changes. In this work we present an approach for geo-locating a novel
view and determining camera location and orientation using a map and a sparse
set of geo-tagged reference views. We propose a novel technique for detection
and identification of building facades from geo-tagged reference view using the
map and geometry of the building facades. We compute the likelihood of camera
location and orientation of the query images using the detected landmark
(building) identities from reference views, 2D map of the environment, and
geometry of building facades. We evaluate our approach for building
identification and geo-localization on a new challenging outdoors urban dataset
exhibiting large variations in appearance and viewpoint.


title:
A characterization of $n$-associative, monotone, idempotent functions on
  an interval that have neutral elements

abstract:
  We investigate monotone idempotent $n$-ary semigroups. One of the main result
of this article is the generalisation of Czogala-Drewniak Theorem, which
describes the idempotent monotone associative functions having neutral element.
Furthermore we present the full characterisation of idempotent, monotone,
$n$-associative functions on an interval which have neutral elements. %{\bl
defined}. Our description provides that monotone, idempotent, $n$-ary
semigroups are quasitrivial.


title: Emergent SO(3) Symmetry of the Frictionless Shear Jamming Transition

abstract:
  We study the shear jamming of athermal frictionless soft spheres, and find
that in the thermodynamic limit, a shear-jammed state exists with different
elastic properties from the isotropically-jammed state. For example,
shear-jammed states can have a non-zero residual shear stress in the
thermodynamic limit that arises from long-range stress-stress correlations. As
a result, the ratio of the shear and bulk moduli, which in isotropically-jammed
systems vanishes as the jamming transition is approached from above, instead
approaches a constant. Despite these striking differences, we argue that in a
deeper sense, the shear jamming and isotropic jamming transitions actually have
the same symmetry, and that the differences can be fully understood by rotating
the six-dimensional basis of the elastic modulus tensor.


title:
Observation of oscillatory radial electric field relaxation in a helical
  plasma

abstract:
  Measurements of the relaxation of a zonal electrostatic potential
perturbation in a non-axisymmetric magnetically confined plasma are presented.
A sudden perturbation of the plasma equilibrium is induced by the injection of
a cryogenic hydrogen pellet in the TJ-II stellarator, which is observed to be
followed by a damped oscillation in the electrostatic potential. The waveform
of the relaxation is consistent with theoretical calculations of zonal
potential relaxation in a non-axisymmetric magnetic geometry. The turbulent
transport properties of a magnetic confinement configuration are expected to
depend on the features of the collisionless damping of zonal flows, of which
the present letter is the first direct observation.


title: A 2D Stress Tensor for 4D Gravity

abstract:
  We use the subleading soft-graviton theorem to construct an operator $T_{zz}$
whose insertion in the four-dimensional tree-level quantum gravity
$\mathcal{S}$-matrix obeys the Virasoro-Ward identities of the energy momentum
tensor of a two-dimensional conformal field theory (CFT$_2$). The celestial
sphere at Minkowskian null infinity plays the role of the Euclidean sphere of
the CFT$_2$, with the Lorentz group acting as the unbroken $SL(2,\mathbb{C})$
subgroup.


title: Consensus over Weighted Directed Graphs: A Robustness Perspective

abstract:
  The present paper investigates the robustness of the consensus protocol over
weighted directed graphs using the Nyquist criterion. The limit to which a
single weight can vary, while consensus among the agents can be achieved, is
explicitly derived. It is shown that even with a negative weight on one of the
edges, consensus may be achieved. The result obtained in this paper is applied
to a directed acyclic graph and to the directed cycle graph. Graph theoretic
interpretations of the limits are provided for the two cases. Simulations
support the theoretical results.


title: Reconstruction from $k$-decks for graphs with maximum degree 2

abstract:
  The $k$-deck of a graph is its multiset of induced subgraphs on $k$ vertices.
We prove that $n$-vertex graphs with maximum degree $2$ have the same $k$-decks
if each cycle has at least $k+1$ vertices, each path component has at least
$k-1$ vertices, and the number of edges is the same. Using this for lower
bounds, we obtain for each graph with maximum degree at most $2$ the least $k$
such that it is determined by its $k$-deck. For the $n$-vertex cycle this value
is $\lfloor n/2 \rfloor$, and for the $n$-vertex path it is $\lfloor n/2
\rfloor+1$. Also, the least $k$ such that the $k$-deck of an $n$-vertex graph
always determines whether it is connected is at least $\lfloor n/2 \rfloor +1$.


title: Understanding Trainable Sparse Coding via Matrix Factorization

abstract:
  Sparse coding is a core building block in many data analysis and machine
learning pipelines. Typically it is solved by relying on generic optimization
techniques, that are optimal in the class of first-order methods for
non-smooth, convex functions, such as the Iterative Soft Thresholding Algorithm
and its accelerated version (ISTA, FISTA). However, these methods don't exploit
the particular structure of the problem at hand nor the input data
distribution. An acceleration using neural networks was proposed in
\cite{Gregor10}, coined LISTA, which showed empirically that one could achieve
high quality estimates with few iterations by modifying the parameters of the
proximal splitting appropriately.
  In this paper we study the reasons for such acceleration. Our mathematical
analysis reveals that it is related to a specific matrix factorization of the
Gram kernel of the dictionary, which attempts to nearly diagonalise the kernel
with a basis that produces a small perturbation of the $\ell_1$ ball. When this
factorization succeeds, we prove that the resulting splitting algorithm enjoys
an improved convergence bound with respect to the non-adaptive version.
Moreover, our analysis also shows that conditions for acceleration occur mostly
at the beginning of the iterative process, consistent with numerical
experiments. We further validate our analysis by showing that on dictionaries
where this factorization does not exist, adaptive acceleration fails.


title:
PCA-based estimation for functional linear regression with functional
  responses

abstract:
  This paper studies a regression model where both predictor and response
variables are random functions. We consider a functional linear model where the
conditional mean of the response variable at each time point is given by a
linear functional of the predictor variable. In this paper, we are interested
in estimation of the integral kernel $b(s,t)$ of the conditional expectation
operator, where $s$ is an output variable while $t$ is a variable that
interacts with the predictor variable. This problem is an ill-posed inverse
problem, and we consider two estimators based on the functional principal
component analysis (PCA). We show that under suitable regularity conditions, an
estimator based on the single truncation attains the convergence rate for the
integrated squared error that is characterized by smoothness of the function $b
(s,t)$ in $t$ together with the decay rate of the eigenvalues of the covariance
operator, but the rate does not depend on smoothness of $b(s,t)$ in $s$. This
rate is shown to be minimax optimal, and consequently smoothness of $b(s,t)$ in
$s$ does not affect difficulty of estimating $b$. We also consider an
alternative estimator based on the double truncation, and provide conditions
under which the alternative estimator attains the optimal rate. We conduct
simulations to verify the performance of PCA-based estimators in the finite
sample. Finally, we apply our estimators to investigate the relation between
the lifetime pattern of working hours and total income, and the relation
between the electricity spot price and the wind power infeed.


title:
The Impact of Surface Geometry, Cavitation, and Condensation on Wetting
  Transitions: Posts and Reentrant Structures

abstract:
  The fundamental impacts of surface geometry on the stability of wetting
states, and the transitions between them are elucidated for posts and reentrant
structures in both two and three dimensions. We identify three principal
outcomes of particular importance for future surface design of liquid-repellent
surfaces. Firstly, we demonstrate and quantify how capillary condensation and
vapour cavitation affect wetting state stabilities, and the roles condensates
play in wetting transitions. Crucially, this leads to a description of the
surface structures which exhibit a suspended state in the absence of a
collapsed state. Secondly, two distinct collapse mechanisms are observed for 3D
reentrant geometries, Base Contact and Pillar Contact, which are operative at
different pillar heights. As well as morphological differences in the
penetrating liquid, each mechanism is affected differently by changes in the
contact angle with the solid. Finally, symmetry breaking is shown to be
prevalent in 2D systems, but absent in the 3D equivalents. For the 2D reentrant
geometries, three pillar heigh-dependent collapse mechanisms are shown:
asymmetric Pillar Contact and Base Contact, and a third hybrid mode.


title: A Unified View of Multi-Label Performance Measures

abstract:
  Multi-label classification deals with the problem where each instance is
associated with multiple class labels. Because evaluation in multi-label
classification is more complicated than single-label setting, a number of
performance measures have been proposed. It is noticed that an algorithm
usually performs differently on different measures. Therefore, it is important
to understand which algorithms perform well on which measure(s) and why. In
this paper, we propose a unified margin view to revisit eleven performance
measures in multi-label classification. In particular, we define label-wise
margin and instance-wise margin, and prove that through maximizing these
margins, different corresponding performance measures will be optimized. Based
on the defined margins, a max-margin approach called LIMO is designed and
empirical results verify our theoretical findings.


title:
Characterization of Three-Dimensional Microstructures in Single Crystal
  Diamond

abstract:
  We report on the Raman and photoluminescence characterization of
three-dimensional microstructures created in single crystal diamond with a
Focused Ion Beam (FIB) assisted lift-off technique. The method is based on MeV
ion implantation to create a buried etchable layer, followed by FIB patterning
and selective etching. In the applications of such microstructures where the
properties of high quality single crystal diamond are most relevant, residual
damage after the fabrication process represents a critical technological issue.
The results of Raman and photoluminescence characterization indicate that the
partial distortion of the sp3-bonded lattice and the formation of isolated
point defects are effectively removed after thermal annealing, leaving low
amounts of residual damage in the final structures. Three-dimensional
microstructures in single-crystal diamond offer a large range of applications,
such as quantum optics devices and fully integrated opto mechanical assemblies.


title: Counting strongly connected $(k_1,k_2)$-directed cores

abstract:
  Consider the set of all digraphs on $[N]$ with $M$ edges, whose minimum
in-degree and minimum out-degree are at least $k_1$ and $k_2$ respectively. For
$k:=\min\{k_1,k_2\}\ge 2$ and $M/N>\max\{k_1,k_2\}$, $M=\Theta(N)$, we show
that, among those digraphs, the fraction of $k$-strongly connected digraphs is
$1-O\bigl(N^{-(k-1)})$. Earlier with Dan Poole we identified a sharp
edge-density threshold $c^*(k_1,k_2)$ for birth of a giant $(k_1,k_2)$-core in
the random digraph $D(n,m=[cn])$. Combining the claims, for $c>c^*(k_1,k_2)$
with probability $1-O\bigl(N^{-(k-1)})$ the giant $(k_1,k_2)$-core exists and
is $k$-strongly connected.


title: A Non-iterative Method for (Re)Construction of Phase from STFT Magnitude

abstract:
  A non-iterative method for the construction of the Short-Time Fourier
Transform (STFT) phase from the magnitude is presented. The method is based on
the direct relationship between the partial derivatives of the phase and the
logarithm of the magnitude of the un-sampled STFT with respect to the Gaussian
window. Although the theory holds in the continuous setting only, the
experiments show that the algorithm performs well even in the discretized
setting (Discrete Gabor transform) with low redundancy using the sampled
Gaussian window, the truncated Gaussian window and even other compactly
supported windows like the Hann window.
  Due to the non-iterative nature, the algorithm is very fast and it is
suitable for long audio signals. Moreover, solutions of iterative phase
reconstruction algorithms can be improved considerably by initializing them
with the phase estimate provided by the present algorithm.
  We present an extensive comparison with the state-of-the-art algorithms in a
reproducible manner.


title: Crowdsourcing with Unsure Option

abstract:
  One of the fundamental problems in crowdsourcing is the trade-off between the
number of the workers needed for high-accuracy aggregation and the budget to
pay. For saving budget, it is important to ensure high quality of the
crowd-sourced labels, hence the total cost on label collection will be reduced.
Since the self-confidence of the workers often has a close relationship with
their abilities, a possible way for quality control is to request the workers
to return the labels only when they feel confident, by means of providing
unsure option to them. On the other hand, allowing workers to choose unsure
option also leads to the potential danger of budget waste. In this work, we
propose the analysis towards understanding when providing the unsure option
indeed leads to significant cost reduction, as well as how the confidence
threshold is set. We also propose an online mechanism, which is alternative for
threshold selection when the estimation of the crowd ability distribution is
difficult.


title:
Narrowest-Over-Threshold Detection of Multiple Change-points and
  Change-point-like Features

abstract:
  We propose a new, generic and flexible methodology for nonparametric function
estimation, in which we first estimate the number and locations of any features
that may be present in the function, and then estimate the function
parametrically between each pair of neighbouring detected features. Examples of
features handled by our methodology include change-points in the
piecewise-constant signal model, kinks in the piecewise-linear signal model,
and other similar irregularities, which we also refer to as generalised
change-points.
  Our methodology works with only minor modifications across a range of
generalised change-point scenarios, and we achieve such a high degree of
generality by proposing and using a new multiple generalised change-point
detection device, termed Narrowest-Over-Threshold (NOT). The key ingredient of
NOT is its focus on the smallest local sections of the data on which the
existence of a feature is suspected. Crucially, this adaptive localisation
technique prevents NOT from considering subsamples containing two or more
features, a key factor that ensures the general applicability of NOT.
  For selected scenarios, we show the consistency and near-optimality of NOT in
detecting the number and locations of generalised change-points. Furthermore,
we propose to select NOT's threshold (automatically) via the strengthened
Schwarz Information Criterion (sSIC) and give theoretical justifications. The
NOT estimators are easy to implement and rapid to compute: the entire
threshold-indexed solution path can be computed in close-to-linear time.
Importantly, the NOT approach is easy to extend by the user to tailor to their
own needs. There is no single competitor, but we show that the performance of
NOT matches or surpasses the state of the art in the scenarios tested. Our
methodology is implemented in the R package \textbf{not}.


title: Single-particle and collective excitations in $^{62}$Ni

abstract:
  {\bf Background:} Level sequences of rotational character have been observed
in several nuclei in the $A=60$ mass region. The importance of the
deformation-driving $\pi f_{7/2}$ and $\nu g_{9/2}$ orbitals on the onset of
nuclear deformation is stressed.\\ {\bf Purpose:} A measurement was performed
in order to identify collective rotational structures in the relatively
neutron-rich $^{62}$Ni isotope. \\ {\bf Method:} The
$^{26}$Mg($^{48}$Ca,2$\alpha$4$n\gamma$)$^{62}$Ni complex reaction at beam
energies between 275 and 320~MeV was utilized. Reaction products were
identified in mass ($A$) and charge ($Z$) with the Fragment Mass Analyzer (FMA)
and $\gamma$ rays were detected with the Gammasphere array. \\ {\bf Results:}
Two collective bands, built upon states of single-particle character, were
identified and sizable deformation was assigned to both sequences based on the
measured transitional quadrupole moments, herewith quantifying the deformation
at high spin. \\ {\bf Conclusions:} Based on Cranked Nilsson-Strutinsky
calculations and comparisons with deformed bands in the $A=60$ mass region, the
two rotational bands are understood as being associated with configurations
involving multiple $f_{7/2}$ protons and $g_{9/2}$ neutrons, driving the
nucleus to sizable prolate deformation.


title: Some New Results on Integer Additive Set-Valued Signed Graphs

abstract:
  Let $X$ denotes a set of non-negative integers and $\mathscr{P}(X)$ be its
power set. An integer additive set-labeling (IASL) of a graph $G$ is an
injective set-valued function $f:V(G)\to \mathscr{P}(X)-\{\emptyset\}$ such
that the induced function $f^+:E(G) \to \mathscr{P}(X)-\{\emptyset\}$ is
defined by $f^+(uv)=f(u)+f(v);\ \forall\, uv\in E(G)$, where $f(u)+f(v)$ is the
sumset of $f(u)$ and $f(v)$. An IASL of a signed graph is an IASL of its
underlying graph $G$ together with the signature $\sigma$ defined by
$\sigma(uv)=(-1)^{|f^+(uv)|};\ \forall\, uv\in E(\Sigma)$. In this paper, we
discuss certain characteristics of the signed graphs which admits certain types
of integer additive set-labelings.


title:
Alpha clustering in $^{28}$Si probed through the identification of
  high-lying $0^+$ states

abstract:
  Aspects of nuclear structure in alpha-conjugate nuclei have long been
associated with alpha clustering, including the existence of superdeformed
bands. In this paper, an alpha-particle inelastic scattering experiment
investigating the location of $0^+$ states in $^{28}$Si is reported in an
attempt to locate possible cluster states. The results are compared to a
semi-microscopic model which shows good agreement with the data, and supports
the assignment of a newly discovered $0^+$ state as the band-head of a
previously observed superdeformed band in $^{28}$Si


title:
Gravitational waves and Higgs boson couplings for exploring first order
  phase transition in the model with a singlet scalar field

abstract:
  We calculate the spectrum of gravitational waves originated from strongly
first order electroweak phase transition in the extended Higgs model with a
real singlet field. In order to calculate the bubble nucleation rate, we
perform a two-field analysis to evaluate bounce solutions connecting the true
and the false vacua using the one-loop effective potential at finite
temperatures. Imposing the Sakharov condition of the departure from thermal
equilibrium for baryogenesis, we survey allowed regions of parameters of the
model. We then investigate the gravitational waves produced at electroweak
bubble collisions in the early Universe, such as the sound wave, the bubble
wall collision and the plasma turbulence. We find that the strength at the peak
frequency can be large enough to be detected at future space-based
gravitational interferometers such as eLISA, DECIGO and BBO. Predicted
deviations in the various Higgs boson couplings are also evaluated at the zero
temperature, and are shown to be large enough too. Therefore, in this model
strongly first order electroweak phase transition can be tested by the
combination of the precision study of various Higgs boson couplings at LHC, the
measurement of the triple Higgs boson coupling at future lepton colliders and
the shape of the spectrum of gravitational wave detectable at future
gravitational interferometers.


title:
Intermediate disorder limits for multi-layer semi-discrete directed
  polymers

abstract:
  We show that the partition function of the multi-layer semi-discrete directed
polymer converges in the intermediate disorder regime to the partition function
for the multi-layer continuum polymer introduced by O'Connell and Warren. This
verifies, modulo a previously hidden constant, an outstanding conjecture
proposed by Corwin and Hammond. A consequence is the identification of the KPZ
line ensemble as logarithms of ratios of consecutive layers of the continuum
partition function. Other properties of the continuum partition function, such
as continuity, strict positivity and contour integral formulas to compute mixed
moments, are also identified from this convergence result.


title: The valuative capacity of the set of sums of $d$-th powers

abstract:
  If $E$ is a subset of the integers then the $n$-th characteristic ideal of
$E$ is the fractional ideal of $\mathbb{Z} $ consisting of $0$ and the leading
coefficients of the polynomials in $\mathbb{Q}[x]$ of degree no more than $n$
which are integer valued on $E$. For $p$ a prime the characteristic sequence of
$Int(E,\mathbb{Z})$ is the sequence $\alpha_E (n)$ of negatives of the $p$-adic
valuations of these ideals. The asymptotic limit $\lim_{n\to
\infty}\frac{\alpha_{E,p}(n)}{n}$ of this sequence, called the valuative
capacity of $E$, gives information about the geometry of $E$. We compute these
valuative capacities for the sets $E$ of sums of $\ell \geq 2$ integers to the
power of $d$, by observing the $p$-adic closure of these sets.


title:
QoS Provisioning with Adaptive Backoff Algorithm for IEEE 802.11ac Under
  Multipacket Reception

abstract:
  Recent advances in physical layer communication techniques, enable receivers
to decode multiple simultaneous transmissions. This technique is known as the
multipacket reception (MPR). In this paper, we propose an enhancement to the
IEEE 802.11ac EDCA protocol for channels supporting MPR for QoS provisioning.
We show that in the case of MPR, in addition to CWmin, CWmax and AIFSN, we can
use two more parameters namely (i) threshold and (ii) counter decrement value,
that can offer service differentiation. The performance evaluation of the
different metrics of the proposed protocol (throughput, delay, and jitter) is
carried out using extensive simulations.


title:
The lensing and temperature imprints of voids on the Cosmic Microwave
  Background

abstract:
  We have searched for the signature of cosmic voids in the CMB, in both the
Planck temperature and lensing-convergence maps; voids should give decrements
in both. We use zobov voids from the DR12 SDSS CMASS galaxy sample. We base our
analysis on N-body simulations, to avoid a posteriori bias. For the first time,
we detect the signature of voids in CMB lensing: the significance is
$3.2\sigma$, close to $\Lambda$CDM in both amplitude and projected
density-profile shape. A temperature dip is also seen, at modest significance
($2.3\sigma$), with amplitude about 6 times the prediction. This temperature
signal is induced mostly by voids with radius between 100 and 150 Mpc/h, while
the lensing signal is mostly contributed by smaller voids -- as expected;
lensing relates directly to density, while ISW depends on gravitational
potential. The void abundance in observations and simulations agree, as well.
We also repeated the analysis excluding lower-significance voids: no lensing
signal is detected, with an upper limit of about twice the $\Lambda$CDM
prediction. But the mean temperature decrement now becomes non-zero at the
$3.7\sigma$ level (similar to that found by Granett et al.), with amplitude
about 20 times the prediction. However, the observed dependence of temperature
on void size is in poor agreement with simulations, whereas the lensing results
are consistent with $\Lambda$CDM theory. Thus, the overall tension between
theory and observations does not favour non-standard theories of gravity,
despite the hints of an enhanced amplitude for the ISW effect from voids.


title:
Sampling-based verification of Lyapunov's inequality for piecewise
  continuous nonlinear systems

abstract:
  This paper considers a sampling-based approach to stability verification for
piecewise continuous nonlinear systems via Lyapunov functions. Depending on the
system dynamics, the candidate Lyapunov function and the set of initial states
of interest, one generally needs to handle large, possibly non-convex or
non-feasible optimization problems. To avoid such problems, we propose a
constructive and systematically applicable sampling-based method to Lyapunov's
inequality verification. This approach proposes verification of the decrease
condition for a candidate Lyapunov function on a finite sampling of a bounded
set of initial conditions and then it extends the validity of the Lyapunov
function to an infinite set of initial conditions by automatically exploiting
continuity properties. This result is based on multi-resolution sampling, to
perform efficient state- space exploration. Using hyper-rectangles as basic
sampling blocks, to account for different constraint scales on different
states, further reduces the amount of samples to be verified. Moreover, the
verification is decentralized in the sampling points, which makes the method
scalable. The proposed methodology is illustrated through examples.


title: Group actions on dendrites and curves

abstract:
  We establish obstructions for groups to act by homeomorphisms on dendrites.
For instance, lattices in higher rank simple Lie groups will always fix a point
or a pair. The same holds for irreducible lattices in products of connected
groups. Further results include a Tits alternative and a description of the
topological dynamics.
  We briefly discuss to what extent our results hold for more general
topological curves.


title:
Advanced surface characterization of
  Ba(Fe$_{0.92}$Co$_{0.08}$)$_2$As$_2$ epitaxial thin films

abstract:
  We report on the systematic characterization of
Ba(Fe$_{0.92}$Co$_{0.08}$)$_2$As$_2$ epitaxial thin films on CaF$_2$ substrate
in view of their possible use for superconducting electronic applications. By
using different and complementary techniques we studied the morphological
characteristics of the surface, the structural properties, the magnetic
response, and the superconducting properties in terms of critical temperature,
critical current, and energy gaps. Particular attention was paid to the
homogeneity of the films and to the comparison of their superconducting
properties with those of single crystals of the same compound.


title: Quantum walking in curved spacetime: $(3+1)$ dimensions, and beyond

abstract:
  A discrete-time Quantum Walk (QW) is essentially an operator driving the
evolution of a single particle on the lattice, through local unitaries. Some
QWs admit a continuum limit, leading to familiar PDEs (e.g. the Dirac
equation). Recently it was discovered that prior grouping and encoding allows
for more general continuum limit equations (e.g. the Dirac equation in $(1+1)$
curved spacetime). In this paper, we extend these results to arbitrary space
dimension and internal degree of freedom. We recover an entire class of PDEs
encompassing the massive Dirac equation in $(3+1)$ curved spacetime. This means
that the metric field can be represented by a field of local unitaries over a
lattice.


title: On-Chip Mechanisms to Reduce Effective Memory Access Latency

abstract:
  This dissertation develops hardware that automatically reduces the effective
latency of accessing memory in both single-core and multi-core systems. To
accomplish this, the dissertation shows that all last level cache misses can be
separated into two categories: dependent cache misses and independent cache
misses. Independent cache misses have all of the source data that is required
to generate the address of the memory access available on-chip, while dependent
cache misses depend on data that is located off-chip. This dissertation
proposes that dependent cache misses are accelerated by migrating the
dependence chain that generates the address of the memory access to the memory
controller for execution. Independent cache misses are accelerated using a new
mode for runahead execution that only executes filtered dependence chains. With
these mechanisms, this dissertation demonstrates a 62% increase in performance
and a 19% decrease in effective memory access latency for a quad-core processor
on a set of high memory intensity workloads.


title:
Transmission-matrix-based point-spread-function engineering through a
  complex medium

abstract:
  We report a method to design at will the spatial profile of transmitted
coherent light after propagation through a scattering sample. We compute an
operator based on the experimentally measured transmission matrix, obtained by
numerically adding an arbitrary mask in the Fourier domain prior to focusing.
We demonstrate the strength of the technique through several examples:
propagating Bessel beams, thus generating foci smaller than the diffraction
limited speckle grain, donut beams, and helical beams. We characterize the 3D
profile of the achieved foci and analyze the fundamental limitations of the
technique. Our approach generalizes Fourier optics concepts for random media,
and opens in particular interesting perspectives for super-resolution imaging
through turbid media.


title:
Shedding light onto topological insulator beads: perspectives for
  optical tweezing application

abstract:
  The interaction of electromagnetic radiation with a spheric-type
three-dimensional topological insulator (TI) bead is described within classical
optics framework. By virtue of the topological magnetoelectric effect (TMEE)
experienced by reflected and transmitted rays at the TI surface, there appears
a net constant force on the spherical bead which is proportional to the fine
structure constant times the incident radiation power. Such an uniform dynamics
(constant acceleration) may be particularly useful for optical tweeezing
techniques, for instance, to investigate a DNA strip or a membrane piece under
stretching as well as to displace a tiny object by means of purely optical
control.


title: Quasi-Periodic Solutions For Nonlinear Klein-Gordon Equations

abstract:
  We present a set of time quasi-periodic solutions to a nonlinear Klein-Gordon
equation with a decaying nonlinear term on the torus in arbitrary dimensions.
This paper generalizes the bifurcation method developed in [W2].


title: On Exceptional Instanton Strings

abstract:
  According to a recent classification of 6d (1,0) theories within F-theory
there are only six "pure" 6d gauge theories which have a UV superconformal
fixed point. The corresponding gauge groups are $SU(3),SO(8),F_4,E_6,E_7$, and
$E_8$. These exceptional models have BPS strings which are also instantons for
the corresponding gauge groups. For $G$ simply-laced, we determine the 2d
$\mathcal{N}=(0,4)$ worldsheet theories of such BPS instanton strings by a
simple geometric engineering argument. These are given by a twisted $S^2$
compactification of the 4d $\mathcal{N}=2$ theories of type $H_2, D_4, E_6,
E_7$ and $E_8$ (and their higher rank generalizations), where the 6d instanton
number is mapped to the rank of the corresponding 4d SCFT. This determines
their anomaly polynomials and, via topological strings, establishes an
interesting relation among the corresponding $T^2 \times S^2$ partition
functions and the Hilbert series for moduli spaces of $G$ instantons. Such
relations allow to bootstrap the corresponding elliptic genera by modularity.
As an example of such procedure, the elliptic genera for a single instanton
string are determined. The same method also fixes the elliptic genus for case
of one $ F_4 $ instanton. These results unveil a rather surprising relation
with the Schur index of the corresponding 4d $\mathcal{N}=2$ models.


title: Cuba: the strategic choice of advanced scientific development, 1959-2014

abstract:
  Cuba is continuing attracting the attention of the international scientific
community for some important and unexpected achievements in applied science
such as health biotechnology. They represent outcomes of the 1959 decision of
Cuba to develop an advanced scientific system in order to address the most
urgent problems for the development of the country and to overcome the
condition of subalternity. This ambitious objective was tackled in a very
original way, making a broad and wide-ranging recourse to every effective
support and collaboration, with Soviet but also Western scientists and
institutions, in addition to a peculiar Cuban inventiveness. Indeed,
immediately after the revolution, Cuba developed an advanced and articulated
scientific system, and achieved a level of excellence in leading scientific
fields, like biotechnology, quite independently from the Soviet Union, which
was behind in this field. Even the collapse of the Soviet Union in the early
1990s, that could have put the achievements of the Revolution at risk, posing
again the threat of subalternity, under an intentionally worsened American
embargo, did not change this trend: once more Cuba addressed this challenge
reconfirming the strategic choice of supporting its most advanced and
profitable scientific sectors, especially the capital-intensive and typically
American field of health biotechnologies. This strategy proved to be once again
a well-chosen course of action.


title:
Quantum correlation enhanced super-resolution localization microscopy
  enabled by a fiber bundle camera

abstract:
  Despite advances in low-light level detection, single-photon methods such as
photon correlation have rarely been used in the context of imaging. The few
demonstrations, for example of sub-diffraction limited imaging utilizing
quantum statistics of photons, have remained in the realm of proof-of-principle
demonstrations. This is primarily due to a combination of low values of fill
factors, quantum efficiencies, frame rates and signal-to-noise characteristic
of most available single-photon sensitive imaging detectors. Here we describe
an imaging device based on a fiber bundle coupled to single-photon avalanche
detectors, which combines a large fill factor, a high quantum efficiency, a low
noise and scalable architecture. Our device enables localization based
super-resolution microscopy in a non-sparse non-stationary scene, utilizing
information on the number of active emitters, as gathered from non-classical
photon statistics.


title:
Criteria for the growth of fullerenes and single-walled carbon nanotubes
  in sooting environments

abstract:
  The spherical curvature induced by pentagons in corannulenes and hexagonal
sheets is shown to be the basic constituent that controls the growth of
fullerenes and single-walled carbon nanotubes (SWNTs) in soot forming and
carbon vapour environments. Formation of the initial ring of five or six atoms
is the essential step which with the addition of further pentagons and hexagons
determines whether a spinning fullerene is to be formed or the cap that lifts
up and leads to the formation of an SWNT. A continuum elastic model is
developed to determine the criteria for the growth of these structures. The
observed dominance of the growth of 14 {\AA} diameter armchair SWNTs in sooting
and carbonaceous environments is explained by using the nanoelastic model of C
shells.


title:
Induced subgraphs of graphs with large chromatic number. V. Chandeliers
  and strings

abstract:
  It is known that every graph of sufficiently large chromatic number and
bounded clique number contains, as an induced subgraph, a subdivision of any
fixed forest, and a subdivision of any fixed cycle. Equivalently, forests and
triangles are pervasive, where H is pervasive (in some class of graphs) if for
all s>0, every graph in the class with bounded clique number and sufficiently
large chromatic number contains an induced subdivision of H, with every edge
subdivided at least s times.
  Which other graphs are pervasive? Chalopin, Esperet, Li and Ossona de Mendez
proved that every such graph is a forest of lanterns: roughly, the blocks are
lanterns (graphs obtained from a tree by adding one extra vertex), and there
are rules about how blocks fit together. It is not known whether every forest
of lanterns is pervasive; but in another paper two of us prove that banana
trees (multigraphs obtained from a forest by adding parallel edges) are
pervasive, thus generalizing the two results above. This paper contains the
first half of the proof, which works for any forest of lanterns, not just for
banana trees.
  A class of graphs is r-controlled if for every graph in the class, its
chromatic number is at most some function (determined by the class) of the
largest chromatic number of an r-ball in the graph. In this paper we prove that
for all r>1, every forest of lanterns is pervasive in every r-controlled class
  These results turn out particularly nicely when applied to string graphs
(intersection graphs of sets of curves in the plane). A chandelier is a graph
obtained from a tree by adding a vertex adjacent to its leaves. We prove that
the class of string graphs is 2-controlled, and thus forests of lanterns are
pervasive in this class. Furthermore, string graphs of sufficiently large
chromatic number and bounded clique number contain any fixed chandelier as an
induced subgraph.


title: Relativistic Killingbeck Energy States Under an External Magnetic Fields

abstract:
  We address the behavior of the Dirac equation with the Killingbeck radial
potential including the external magnetic and Aharonov-Bohm (AB) flux fields.
The spin and pseudo-spin symmetries are considered. The correct bound state
spectra and their corresponding wave functions are obtained. We seek such a
solution using the biconfluent Heun differential equation method. Further, we
give some of our results at the end of this study. Our final results can be
reduced to their non-relativistic forms by simply using some appropriate
transformations. The spectra, in the spin and pseudo-spin symmetries, are very
similar with a slight difference in energy spacing between different states.


title:
Multi-critical absorbing phase transition in a class of exactly solvable
  models

abstract:
  We study diffusion of hardcore particles on a one dimensional periodic
lattice subjected to a constraint that the separation between any two
consecutive particles does not increase beyond a fixed value $(n+1);$ initial
separation larger than $(n+1)$ can however decrease. These models undergo an
absorbing state phase transition when the conserved particle density of the
system falls bellow a critical threshold $\rho_c= 1/(n+1).$ We find that
$\phi_k$s, the density of $0$-clusters ($0$ representing vacancies) of size
$0\le k<n,$ vanish at the transition point along with activity density
$\rho_a$. The steady state of these models can be written in matrix product
form to obtain analytically the static exponents $\beta_k= n-k,\nu=1=\eta$
corresponding to each $\phi_k$. We also show from numerical simulations that
starting from a natural condition, $\phi_k(t)$s decay as $t^{-\alpha_k}$ with
$\alpha_k= (n-k)/2$ even though other dynamic exponents $\nu_t=2=z$ are
independent of $k$; this ensures the validity of scaling laws $\beta= \alpha
\nu_t,$ $\nu_t = z \nu$.


title: The {\kappa}-{\mu} Shadowed Fading Model with Integer Fading Parameters

abstract:
  We show that the popular and general {\kappa}-{\mu} shad- owed fading model
with integer fading parameters {\mu} and m can be represented as a mixture of
squared Nakagami (or Gamma) distributions. Thus, its PDF and CDF can be
expressed in closed-form in terms of a finite number of elementary functions
(powers and exponentials). The main implications arising from such connection
are then discussed, which can be summarized as: (1) the performance evaluation
of communication systems operating in {\kappa}-{\mu} shadowed fading becomes as
simple as if a Nakagami fading channel was assumed; (2) the {\kappa}-{\mu}
shadowed distribution can be used to approximate the {\kappa}-{\mu}
distribution us- ing a closed-form representation in terms of elementary
functions, by choosing a sufficiently large value of m; and (3) restricting the
parameters {\mu} and m to take integer values has limited impact in practice
when fitting the {\kappa}-{\mu} shadowed fading model to field measurements. As
an application example, the average channel capacity of communication systems
operating under {\kappa}-{\mu} shadowed fading is obtained in closed-form.


title: Block BFGS Methods

abstract:
  We introduce a quasi-Newton method with block updates called Block BFGS. We
show that this method, performed with inexact Armijo-Wolfe line searches,
converges globally and superlinearly under the same convexity assumptions as
BFGS. We also show that Block BFGS is globally convergent to a stationary point
when applied to non-convex functions with bounded Hessian, and discuss other
modifications for non-convex minimization. Numerical experiments comparing
Block BFGS, BFGS and gradient descent are presented.


title:
Coupled orbital and spin evolution of the CoRoT-7 two-planet system
  using a Maxwell viscoelastic rheology

abstract:
  We investigate the orbital and rotational evolution of the CoRoT-7 two-planet
system, assuming that the innermost planet behaves like a Maxwell body. We
numerically resolve the coupled differential equations governing the
instantaneous deformation of the inner planet together with the orbital motion
of the system. We show that, depending on the relaxation time for the
deformation of the planet, the orbital evolution has two distinct behaviours:
for relaxation times shorter than the orbital period, we reproduce the results
from classic tidal theories, for which the eccentricity is always damped.
However, for longer relaxation times, the eccentricity of the inner orbit is
secularly excited and can grow to high values. This mechanism provides an
explanation for the present high eccentricity observed for CoRoT-7 b, as well
as for other close-in super-Earths in multiple planetary systems.


title: Le lemme d'Abhyankar perfectoide

abstract:
  We extend Faltings's "almost purity theorem" on finite etale extensions of
perfectoid algebras (as generalized by Scholze and Kedlaya-Liu) to the ramified
case, without restriction on the discriminant. The key point is a perfectoid
version of Riemann's extension theorem. Categorical aspects of uniform Banach
algebras and perfectoid algebras are revisited beforehand.


title: Block Crossings in Storyline Visualizations

abstract:
  Storyline visualizations help visualize encounters of the characters in a
story over time. Each character is represented by an x-monotone curve that goes
from left to right. A meeting is represented by having the characters that
participate in the meeting run close together for some time. In order to keep
the visual complexity low, rather than just minimizing pairwise crossings of
curves, we propose to count block crossings, that is, pairs of intersecting
bundles of lines.
  Our main results are as follows. We show that minimizing the number of block
crossings is NP-hard, and we develop, for meetings of bounded size, a
constant-factor approximation. We also present two fixed-parameter algorithms
and, for meetings of size 2, a greedy heuristic that we evaluate
experimentally.


title: Open Call-by-Value (Extended Version)

abstract:
  The elegant theory of the call-by-value lambda-calculus relies on weak
evaluation and closed terms, that are natural hypotheses in the study of
programming languages. To model proof assistants, however, strong evaluation
and open terms are required, and it is well known that the operational
semantics of call-by-value becomes problematic in this case. Here we study the
intermediate setting -- that we call Open Call-by-Value -- of weak evaluation
with open terms, on top of which Gr\'egoire and Leroy designed the abstract
machine of Coq. Various calculi for Open Call-by-Value already exist, each one
with its pros and cons. This paper presents a detailed comparative study of the
operational semantics of four of them, coming from different areas such as the
study of abstract machines, denotational semantics, linear logic proof nets,
and sequent calculus. We show that these calculi are all equivalent from a
termination point of view, justifying the slogan Open Call-by-Value.


title: Computing partial transposes and related entanglement functions

abstract:
  The partial transpose (PT) is an important function for entanglement testing
and quantification and also for the study of geometrical aspects of the quantum
state space. In this article, considering general bipartite and multipartite
discrete systems, explicit formulas ready for the numerical implementation of
the PT and of related entanglement functions are presented and the Fortran code
produced for that purpose is described. What is more, we obtain an analytical
expression for the Hilbert-Schmidt entanglement of two-qudit systems and for
the associated closest separable state. In contrast to previous works on this
matter, we only use the properties of the PT, not applying Lagrange
multipliers.


title: Uniform Penalty inversion of two-dimensional NMR Relaxation data

abstract:
  The inversion of two-dimensional NMR data is an ill-posed problem related to
the numerical computation of the inverse Laplace transform. In this paper we
present the 2DUPEN algorithm that extends the Uniform Penalty (UPEN) algorithm
[Borgia, Brown, Fantazzini, {\em Journal of Magnetic Resonance}, 1998] to
two-dimensional data. The UPEN algorithm, defined for the inversion of
one-dimensional NMR relaxation data, uses Tikhonov-like regularization and
optionally non-negativity constraints in order to implement locally adapted
regularization. In this paper, we analyze the regularization properties of this
approach. Moreover, we extend the one-dimensional UPEN algorithm to the
two-dimensional case and present an efficient implementation based on the
Newton Projection method. Without any a-priori information on the noise norm,
2DUPEN automatically computes the locally adapted regularization parameters and
the distribution of the unknown NMR parameters by using variable smoothing.
Results of numerical experiments on simulated and real data are presented in
order to illustrate the potential of the proposed method in reconstructing
peaks and flat regions with the same accuracy.


title: Conjugacy search problem and the Andrews-Curtis conjecture

abstract:
  We develop new computational methods for studying potential counterexamples
to the Andrews-Curtis conjecture, in particular, Akbulut-Kurby examples AK(n).
We devise a number of algorithms in an attempt to disprove the most interesting
counterexample AK(3). To improve metric properties of the search space (which
is a set of balanced presentations of the trivial group) we introduce a new
transformation (called an ACM-move here) that generalizes the original
Andrews-Curtis transformations and discuss details of a practical
implementation. To reduce growth of the search space we introduce a strong
equivalence relation on balanced presentations and study the space modulo
automorphisms of the underlying free group. Finally, we prove that
automorphism-moves can be applied to AK(n)-presentations. Unfortunately,
despite a lot of effort we were unable to trivialize any of
AK(n)-presentations, for n>2.


title:
A two-component generalization of the reduced Ostrovsky equation and its
  integrable semi-discrete analogue

abstract:
  In the present paper, we propose a two-component generalization of the
reduced Ostrovsky equation, whose differential form can be viewed as the
short-wave limit of a two-component Degasperis-Procesi (DP) equation. They are
integrable due to the existence of Lax pairs. Moreover, we have shown that
two-component reduced Ostrovsky equation can be reduced from an extended BKP
hierarchy with negative flow through a pseudo 3-reduction and a hodograph
(reciprocal) transform. As a by-product, its bilinear form and $N$-soliton
solution in terms of pfaffians are presented. One- and two-soliton solutions
are provided and analyzed. In the second part of the paper, we start with a
modified BKP hierarchy, which is a B\"acklund transformation of the above
extended BKP hierarchy, an integrable semi-discrete analogue of two-component
reduced Ostrovsky equation is constructed by defining an appropriate discrete
hodograph transform and dependent variable transformations. Especially, the
backward difference form of above semi-discrete two-component reduced Ostrovsky
equation gives rise to the integrable semi-discretization of the short wave
limit of a two-component DP equation. Their $N$-soliton solutions in terms of
pffafians are also provided.


title:
Experimental Evidence for a Structural-Dynamical Transition in
  Trajectory Space

abstract:
  Among the key insights into the glass transition has been the identification
of a non-equilibrium phase transition in trajectory space which reveals phase
coexistence between the normal supercooled liquid (active phase) and a glassy
state (inactive phase). Here we present evidence that such a transition occurs
in experiment. In colloidal hard spheres we find a non-Gaussian distribution of
trajectories leaning towards those rich in locally favoured structures (LFS),
associated with the emergence of slow dynamics. This we interpret as evidence
for an non-equilibrium transition to an inactive LFS-rich phase. Reweighting
trajectories reveals a first-order phase transition in trajectory space between
a normal liquid and a LFS-rich phase. We further find evidence of a purely
dynamical transition in trajectory space.


title: A comment on power-law inflation with a dark radiation component

abstract:
  Tram et al. 2016 recently pointed out that power-law inflation in presence of
a dark radiation component may relieve the 3.3 sigma tension which exists
within standard LCDM between the determination of the local value of the Hubble
constant by Riess et al. (2016) and the value derived from CMB anisotropy data
by the Planck collaboration. In this comment, we simply point out that this
interesting proposal does not help in solving the $\sigma_8$ tension between
the Planck data and, e.g., the weak lensing measurements. Moreover, when the
latest constraints on the reionization optical depth obtained from Planck HFI
data are included in the analysis, the $H_0$ tension reappears and this
scenario looses appeal.


title: Properties of Magnetic Tongues over a Solar Cycle

abstract:
  The photospheric spatial distribution of the main magnetic polarities of
bipolar active regions (ARs) presents during their emergence deformations are
known as magnetic tongues. They are attributed to the presence of twist in the
toroidal magnetic flux-tubes that form the ARs. The aim of this article is to
study the twist of newly emerged ARs from the evolution of magnetic tongues
observed in photospheric line-of-sight magnetograms. We apply the procedure
described by Poisson et al. (2015, Solar Phys. 290, 727) to ARs observed over
the full Solar Cycle 23 and the beginning of Cycle 24. Our results show that
the hemispherical rule obtained using the tongues as a proxy of the twist has a
weak sign-dominance (53 % in the southern hemisphere and 58 % in the northern
hemisphere). By defining the variation of the tongue angle, we characterize the
strength of the magnetic tongues during different phases of the AR emergence.
We find that there is a tendency of the tongues to be stronger during the
beginning of the emergence and to become weaker as the AR reaches its maximum
magnetic flux. We compare this evolution with the emergence of a toroidal
flux-rope model with non-uniform twist. The variety of evolution of the tongues
in the analyzed ARs can only be reproduced when using a broad range of twist
profiles, in particular having a large variety of twist gradient in the
direction vertical to the photosphere. Although the analytical model used is a
special case, selected to minimize the complexity of the problem, the results
obtained set new observational constraints to theoretical models of flux-rope
emergence that form bipolar ARs.


title:
SETI at X-ray Energies - Parasitic Searches from Astrophysical
  Observations

abstract:
  If a sufficiently advanced civilization can either modulate the emission from
an X-ray binary, or make use of the natural high luminosity to power an
artificial transmitter, these can serve as good beacons for interstellar
communication without involving excessive energy costs to the broadcasting
civilization. In addition, the small number of X-ray binaries in the Galaxy
considerably reduces the number of targets that must be investigated compared
to searches in other energy bands. Low mass X-ray binaries containing neutron
stars in particular are considered as prime potential natural and artificial
beacons and high time resolution (better than 1ms) observations are encouraged.
All sky monitors provide the capability of detecting brief powerful artificial
signals from isolated neutron stars. New capabilities of X-ray astronomy
satellites developed for astrophysical purposes are enabling SETI in new
parameter regimes. For example, the X-ray Timing Explorer satellite provides
the capability of exploring the sub-millisecond region. Other planned X-ray
astronomy satellites should provide significantly improved spectral resolution.
While SETI at X-ray energies is highly speculative (and rather unfashionable)
by using a parasitic approach little additional cost is involved. The inclusion
of X-ray binaries in target lists for SETI at radio and other wavebands is also
advocated.


title: Verifier Theory and Unverifiability

abstract:
  Despite significant developments in Proof Theory, surprisingly little
attention has been devoted to the concept of proof verifier. In particular, the
mathematical community may be interested in studying different types of proof
verifiers (people, programs, oracles, communities, superintelligences) as
mathematical objects. Such an effort could reveal their properties, their
powers and limitations (particularly in human mathematicians), minimum and
maximum complexity, as well as self-verification and self-reference issues. We
propose an initial classification system for verifiers and provide some
rudimentary analysis of solved and open problems in this important domain. Our
main contribution is a formal introduction of the notion of unverifiability,
for which the paper could serve as a general citation in domains of theorem
proving, as well as software and AI verification.


title:
Heterogeneous nucleation and heat flux avalanches in La(Fe,Si)$_{13}$
  magnetocaloric compounds near the critical point

abstract:
  The phase transformation kinetics of
LaFe$_{11.41}$Mn$_{0.30}$Si$_{1.29}$-H$_{1.65}$ magnetocaloric compound is
addressed by low rate calorimetry experiments. Scans at 1 mK/s show that its
first order phase transitions are made by multiple heat fllux avalanches.
Getting very close to the critical point, the step-like discontinuous behavior
associated with avalanches is smoothed out and thermal hysteresis disappears.
This result is confirmed by magneto-resistivity measurements and allows to
measure accurate values of the zero field hysteresis ($\Delta T_{hyst}$ = 0.37
K) and of the critical field (H$_c$ = 1.19 T). The number and magnitude of heat
flux avalanches change with magnetic field, showing the interplay between the
intrinsic energy barrier between phases and the microstructural disorder of the
sample.


title:
Microwave spectroscopy of spinful Andreev bound states in ballistic
  semiconductor Josephson junctions

abstract:
  The superconducting proximity effect in semiconductor nanowires has recently
enabled the study of new superconducting architectures, such as gate-tunable
superconducting qubits and multiterminal Josephson junctions. As opposed to
their metallic counterparts, the electron density in semiconductor nanosystems
is tunable by external electrostatic gates providing a highly scalable and
in-situ variation of the device properties. In addition, semiconductors with
large $g$-factor and spin-orbit coupling have been shown to give rise to exotic
phenomena in superconductivity, such as $\varphi_0$ Josephson junctions and the
emergence of Majorana bound states. Here, we report microwave spectroscopy
measurements that directly reveal the presence of Andreev bound states (ABS) in
ballistic semiconductor channels. We show that the measured ABS spectra are the
result of transport channels with gate-tunable, high transmission probabilities
up to $0.9$, which is required for gate-tunable Andreev qubits and beneficial
for braiding schemes of Majorana states. For the first time, we detect
excitations of a spin-split pair of ABS and observe symmetry-broken ABS, a
direct consequence of the spin-orbit coupling in the semiconductor.


title:
Stochastic Dynamics of Extended Objects in Driven Systems II: Current
  Quantization in the Low-Temperature Limit

abstract:
  Driven Langevin processes have appeared in a variety of fields due to the
relevance of natural phenomena having both deterministic and stochastic
effects. The stochastic currents and fluxes in these systems provide a
convenient set of observables to describe their non-equilibrium steady states.
Here we consider stochastic motion of a (k - 1)-dimensional object, which
sweeps out a k-dimensional trajectory, and gives rise to a higher k-dimensional
current. By employing the low-temperature (low-noise) limit, we reduce the
problem to a discrete Markov chain model on a CW complex, a topological
construction which generalizes the notion of a graph. This reduction allows the
mean fluxes and currents of the process to be expressed in terms of solutions
to the discrete Supersymmetric Fokker-Planck (SFP) equation. Taking the
adiabatic limit, we show that generic driving leads to rational quantization of
the generated higher dimensional current. The latter is achieved by
implementing the recently developed tools, coined the higher-dimensional
Kirchhoff tree and co-tree theorems. This extends the study of motion of
extended objects in the continuous setting performed in the prequel to this
manuscript.


title:
First-principles Predictions of Electronic Properties of GaAs1-x-yPyBix
  and GaAs1-x-yPyBix-based Heterojunctions

abstract:
  Significant efficiency droop is a major concern for light-emitting diodes and
laser diodes operating at high current density. Recent study has suggested that
heavily Bi-alloyed GaAs can decrease the non-radiative Auger recombination and
therefore alleviate the efficiency droop. Using density functional theory, we
studied a newly fabricated quaternary alloy, GaAs1-x-yPyBix, which can host
significant amounts of Bi, through calculations of its band gap, spin-orbit
splitting, and band offsets with GaAs. We found that the band gap changes of
GaAs1-x-yPyBix relative to GaAs are determined mainly by the local structural
changes around P and Bi atoms rather than their electronic structure
differences. To obtain alloy with lower Auger recombination than GaAs bulk, we
identified the necessary constraints on the compositions of P and Bi. Finally,
we demonstrated that GaAs/GaAs1-x-yPyBix heterojunctions with potentially low
Auger recombination can exhibit small lattice mismatch and large enough band
offsets for strong carrier confinement. This work shows that the electronic
properties of GaAs1-x-yPyBix are potentially suitable for high-energy infrared
light-emitting diodes and laser diodes with improved efficiency.


title:
Stochastic Dynamics of Extended Objects in Driven Systems: I.
  Higher-Dimensional Currents in the Continuous Setting

abstract:
  The probability distributions, as well as the mean values of stochastic
currents and fluxes, associated with a driven Langevin process, provide a good
and topologically protected measure of how far a stochastic system is driven
out of equilibrium. By viewing a Langevin process on a compact oriented
manifold of arbitrary dimension m as a theory of a random vector field
associated with the environment, we are able to consider stochastic motion of
higher-dimensional objects, which allow new observables, called
higher-dimensional currents, to be introduced. These higher dimensional
currents arise by counting intersections of a k-dimensional trajectory,
produced by a evolving (k-1)-dimensional cycle, with a reference cross section,
represented by a cycle of complimentary dimension (m - k). We further express
the mean fluxes in terms of the solutions of the Supersymmetric Fokker-Planck
(SFP), thus generalizing the corresponding well-known expressions for the
conventional currents.


title: Free and Non-free Multiplicities on the $A_3$ Arrangement

abstract:
  We give a complete classification of free and non-free multiplicities on the
$A_3$ braid arrangement. Namely, we show that all free multiplicities on $A_3$
fall into two families that have been identified by Abe-Terao-Wakefield (2007)
and Abe-Nuida-Numata (2009). The main tool is a new homological obstruction to
freeness derived via a connection to multivariate spline theory.


title: Extremes of $q$-Ornstein-Uhlenbeck processes

abstract:
  The $q$-Ornstein-Uhlenbeck processes, $q\in(-1,1)$, are a family of
stationary Markov processes that converge weakly to the standard
Ornstein-Uhlenbeck process as $q$ tends to 1. It has been noticed recently that
in terms of path properties, however, for each $q$ fixed the
$q$-Ornstein-Uhlenbeck process behaves qualitatively different from their
Gaussian counterpart in several aspects. Here, two limit theorems on the
extremes of $q$-Ornstein-Uhlenbeck processes are established. Both results are
based on the weak convergence of the tangent process at the lower boundary, a
positive self-similar Markov process little investigated so far in the
literature. The first result is the asymptotic excursion probability
established by the double-sum method, with an explicit formula for the Pickands
constant in this context. The second result is a Brown-Resnick-type limit
theorem on the minimum process of i.i.d. copies. With appropriate scalings in
both time and magnitude, a new semi-min-stable process arises in the limit.


title: Inference in a bimodal Birnbaum-Saunders model

abstract:
  We address the issue of performing inference on the parameters that index a
bimodal extension of the Birnbaum-Saunders distribution (BS). We show that
maximum likelihood point estimation can be problematic since the standard
nonlinear optimization algorithms may fail to converge. To deal with this
problem, we penalize the log-likelihood function. The numerical evidence we
present show that maximum likelihood estimation based on such penalized
function is made considerably more reliable. We also consider hypothesis
testing inference based on the penalized log-likelihood function. In
particular, we consider likelihood ratio, signed likelihood ratio, score and
Wald tests. Bootstrap-based testing inference is also considered. We use a
nonnested hypothesis test to distinguish between two bimodal BS laws. We derive
analytical corrections to some tests. Monte Carlo simulation results and
empirical applications are presented and discussed.


title:
Measuring nonlinear stresses generated by defects in 3D colloidal
  crystals

abstract:
  The mechanical, structural and functional properties of crystals are
determined by their defects and the distribution of stresses surrounding these
defects has broad implications for the understanding of transport phenomena.
When the defect density rises to levels routinely found in real-world
materials, transport is governed by local stresses that are predominantly
nonlinear. Such stress fields however, cannot be measured using conventional
bulk and local measurement techniques. Here, we report direct and spatially
resolved experimental measurements of the nonlinear stresses surrounding
colloidal crystalline defect cores, and show that the stresses at vacancy cores
generate attractive interactions between them. We also directly visualize the
softening of crystalline regions surrounding dislocation cores, and find that
stress fluctuations in quiescent polycrystals are uniformly distributed rather
than localized at grain boundaries, as is the case in strained atomic
polycrystals. Nonlinear stress measurements have important implications for
strain hardening, yield, and fatigue.

categories: cond-mat.mtrl-sci cond-mat.soft cond-mat.stat-mech physics.flu-dyn


title: Linear Convergence of Projection Algorithms

abstract:
  Projection algorithms are well known for their simplicity and flexibility in
solving feasibility problems. They are particularly important in practice due
to minimal requirements for software implementation and maintenance. In this
work, we study linear convergence of several projection algorithms for systems
of finitely many closed sets. The results complement contemporary research on
the same topic.


title:
The role of the internal demagnetizing field in a surface-modulated
  magnonic crystal

abstract:
  Magnonic crystals with locally alternating properties and specific
periodicities exhibit interesting effects, such as a multitude of different
spin-wave states and large band gaps. This work aims for demonstrating and
understanding the key role of local demagnetizing fields in such systems. To
achieve this, hybrid structures are investigated consisting of a continuous
thin film with a stripe modulation on top favorable due to the adjustability of
the magnonic effects with the modulation size. For a direct access to the spin
dynamics, a magnonic crystal was reconstructed from `bottom-up', i.e., the
structural shape as well as the internal field landscape of the structure were
experimentally obtained on the nanoscale using electron holography.
Subsequently, both properties were utilized to perform dynamic response
calculations. The simulations yield the frequency-field dependence as well as
the angular dependence of spin waves in a magnonic crystal and reveal the
governing role of the internal field landscape around the backward-volume
geometry. The complex angle-dependent spin-wave behavior is described for a 360
degree in-plane rotation of an external field by connecting the internal field
landscape with the individual spin-wave localization.


title:
On a completeness problem in a Fourier-based probability metrics in
  $\mathbb{R}^N$

abstract:
  We study completeness of the spaces $\mathcal{P}_s^=$ of probability measures
in $\mathbb{R}^N$ which have equal (prescribed) moments up to order $s \in
\mathbb{N}$, endowed with the metric $d_s(\mu,\nu)=\sup_{x \in
\mathbb{R}^N\setminus 0}\frac{|\hat \mu(x)-\hat \nu(x)|}{|x|^s}$, where $\hat
\mu$ is the characteristic function of $\mu$. We prove that the spaces
$(\mathcal{P}_s^=,d_s)$ are complete if $s$ is even and construct suitable
counterexamples to completeness for all odd $s$. This solves an open problem
formulated by J. Carrillo and G. Toscani in 2007.


title: Deep Learning Human Mind for Automated Visual Classification

abstract:
  What if we could effectively read the mind and transfer human visual
capabilities to computer vision methods? In this paper, we aim at addressing
this question by developing the first visual object classifier driven by human
brain signals. In particular, we employ EEG data evoked by visual object
stimuli combined with Recurrent Neural Networks (RNN) to learn a discriminative
brain activity manifold of visual categories. Afterwards, we train a
Convolutional Neural Network (CNN)-based regressor to project images onto the
learned manifold, thus effectively allowing machines to employ human
brain-based features for automated visual classification. We use a 32-channel
EEG to record brain activity of seven subjects while looking at images of 40
ImageNet object classes. The proposed RNN based approach for discriminating
object classes using brain signals reaches an average accuracy of about 40%,
which outperforms existing methods attempting to learn EEG visual object
representations. As for automated object categorization, our human brain-driven
approach obtains competitive performance, comparable to those achieved by
powerful CNN models, both on ImageNet and CalTech 101, thus demonstrating its
classification and generalization capabilities. This gives us a real hope that,
indeed, human mind can be read and transferred to machines.


title: La conjecture du facteur direct

abstract:
  Building on his reduction to the case of an unramified complete regular local
ring R of mixed characteristic, we propose a proof in the framework of P.
Scholze's perfectoid theory. The main ingredients are the perfectoid "Abhyankar
lemma" and an analysis of Kummer extensions of R by a thickening technique.


title: Characterizing Self-Heating Dynamics Using Cyclostationary Measurements

abstract:
  Self-heating in surrounding gate transistors can degrade its on-current
performance and reduce lifetime. If a transistor heats/cools with
time-constants less than the inverse of the operating frequency, a predictable,
frequency-independent performance is expected; if not, the signal pattern must
be optimized for highest performance. Typically, time-constants are measured by
expensive, ultra-fast instruments with high temporal resolution. Instead, here
we demonstrate an alternate, inexpensive, cyclostationary measurement technique
to characterize self-heating (and cooling) with sub-microsecond resolution. The
results are independently confirmed by direct imaging of the transient
heating/cooling of the channel temperature by the thermoreflectance (TR)
method. A routine use of the proposed technique will help improve the
surrounding gate transistor design and shorten the design cycle.


title:
Thermal Structure and Burning Velocity of Flames in Non-volatile Fuel
  Suspensions

abstract:
  Flame propagation through a non-volatile solid-fuel suspension is studied
using a simplified, time-dependent numerical model that considers the influence
of both diffusional and kinetic rates on the particle combustion process. It is
assumed that particles react via a single-step, first-order Arrhenius surface
reaction with an oxidizer delivered to the particle surface through gas
diffusion. Unlike the majority of models previously developed for flames in
suspensions, no external parameters are imposed, such as particle ignition
temperature, combustion time, or the assumption of either kinetic- or
diffusion-limited particle combustion regimes. Instead, it is demonstrated that
these parameters are characteristic values of the flame propagation problem
that must be solved together with the burning velocity, and that the a priori
imposition of these parameters from single-particle combustion data may result
in erroneous predictions. It is also shown that both diffusive and kinetic
reaction regimes can alternate within the same flame and that their interaction
may result in non-trivial flame behavior. In fuel-lean mixtures, it is
demonstrated that this interaction leads to certain particle size ranges where
burning velocity increases with increasing particle size, opposite to the
expected trend. For even leaner mixtures, the interplay between kinetic and
diffusive reaction rates leads to the appearance of a new type of flame
instability where kinetic and diffusive regimes alternate in time, resulting in
a pulsating regime of flame propagation.


title:
The Cold Neutron Chopper Spectrometer at the Spallation Neutron Source -
  A Review of the first 8 Years of Operation

abstract:
  The first eight years of operation of the Cold Neutron Chopper Spectrometer
(CNCS) at the Spallation Neutron Source in Oak Ridge is being reviewed. The
instrument has been part of the facility user program since 2009, and more than
250 individual user experiments have been performed to date. CNCS is an
extremely powerful and versatile instrument and offers leading edge performance
in terms of beam intensity, energy resolution, and flexibility to trade one for
another. Experiments are being routinely performed with the sample at extreme
conditions: T~0.05K, p>=2GPa and B=8T can be achieved individually or in
combination. In particular, CNCS is in a position to advance the state of the
art with inelastic neutron scattering under pressure, and some of the recent
accomplishments in this area will be presented in more detail.


title:
FFT-PT: Reducing the two-loop large-scale structure power spectrum to
  low-dimensional radial integrals

abstract:
  Modeling the large-scale structure of the universe on nonlinear scales has
the potential to substantially increase the science return of upcoming surveys
by increasing the number of modes available for model comparisons. One way to
achieve this is to model nonlinear scales perturbatively. Unfortunately, this
involves high-dimensional loop integrals that are cumbersome to evaluate.
Trying to simplify this, we show how two-loop (next-to-next-to-leading order)
corrections to the density power spectrum can be reduced to low-dimensional,
radial integrals. Many of those can be evaluated with a one-dimensional Fast
Fourier Transform, which is significantly faster than the five-dimensional
Monte-Carlo integrals that are needed otherwise. The general idea of this
FFT-PT method is to switch between Fourier and position space to avoid
convolutions and integrate over orientations, leaving only radial integrals.
This reformulation is independent of the underlying shape of the initial linear
density power spectrum and should easily accommodate features such as those
from baryonic acoustic oscillations. We also discuss how to account for halo
bias and redshift space distortions.


title:
Higgs potential from extended Brans-Dicke theory and the time-evolution
  of the fundamental constants

abstract:
  Despite the enormous significance of the Higgs potential in the context of
the Standard Model of electroweak interactions and in Grand Unified Theories,
its ultimate origin is fundamentally unknown and must be introduced by hand in
accordance with the underlying gauge symmetry and the requirement of
renormalizability. Here we propose a more physical motivation for the structure
of the Higgs potential, which we link to gravity, and more specifically to an
extended Brans-Dicke (BD) theory containing two interacting scalar fields. One
of these fields is coupled to curvature as in the BD formulation, whereas the
other is coupled to gravity both derivatively and non-derivatively through the
curvature scalar and the Ricci tensor. By requiring that the cosmological
solutions of the model are consistent with observations, we show that the
effective scalar field potential adopts the Higgs potential form with a mildly
time-evolving vacuum expectation value. Such residual vacuum dynamics could be
responsible for the possible time variation of the fundamental constants. The
approach is in part reminiscent of Bjorken's ideas on the cosmological constant
problem.


title:
Exact formulas for radiative heat transfer between planar bodies under
  arbitrary temperature profiles: modified asymptotics and sign-flip
  transitions

abstract:
  We derive exact analytical formulas for the radiative heat transfer between
parallel slabs separated by vacuum and subject to arbitrary temperature
profiles. We show that, depending on the derivatives of the temperature at
points close to the slab--vacuum interfaces, the flux can exhibit one of
several different asymptotic low-distance ($d$) behaviors, obeying either
$1/d^2$, $1/d$, or logarithmic power laws, or approaching a constant. Tailoring
the temperature profile within the slabs could enable unprecedented tunability
over heat exchange, leading for instance to sign-flip transitions (where the
flux reverses sign) at tunable distances. Our results are relevant to the
theoretical description of on-going experiments exploring near-field heat
transfer at nanometric distances, where the coupling between radiative and
conductive heat transfer could be at the origin of temperature gradients.


title: Observation of Weak Collapse in a Bose-Einstein Condensate

abstract:
  We study the collapse of an attractive atomic Bose-Einstein condensate
prepared in the uniform potential of an optical-box trap. We characterise the
critical point for collapse and the collapse dynamics, observing universal
behaviour in agreement with theoretical expectations. Most importantly, we
observe a clear experimental signature of the counterintuitive weak collapse,
namely that making the system more unstable can result in a smaller particle
loss. We experimentally determine the scaling laws that govern the
weak-collapse atom loss, providing a benchmark for the general theories of
nonlinear wave phenomena.

categories: cond-mat.quant-gas nlin.PS physics.optics physics.plasm-ph quant-ph


title:
Notes on Relevant, Irrelevant, Marginal and Extremal Double Trace
  Perturbations

abstract:
  Double trace deformations, that is products of two local operators, define
perturbations of conformal field theories that can be studied exactly in the
large-N limit. Even when the double trace deformation is irrelevant in the
infrared, it is believed to flow to an ultraviolet fixed point. In this note we
define the Kallen-Lehmann representation of the two-point function of a local
operator O in a theory perturbed by the square of such operator. We use such
representation to discover potential pathologies at intermediate points in the
flow that may prevent to reach the UV fixed point. We apply the method to an
"extremal" deformation that naively would flow to a UV fixed point where the
operator O would saturate the unitarity bound. We find that the UV fixed point
is not conformal and that the deformed two-point function propagates unphysical
modes. We interpret the result as showing that the flow to the UV fixed point
does not exist. This resolves a potential puzzle in the holographic
interpretation of the deformation.