title:
Effects of quantum zero-point spin fluctuations on the ground state of
  plutonium

abstract:
  The magnetic stability of {\delta}-plutonium is analyzed taking into account
zero-point spin fluctuations. Within the generalized theory of spin
fluctuations described within a simple phenomenological model neglecting its
spatial dispersion we show that zero-point local magnetic moments are giant
(at.Pu) and suppress the magnetic order predicted by ab initio calculations
resulting in the observed paramagnetic state of {\delta}-plutonium.


title: Higher form gauge fields and their nonassociative symmetry algebras

abstract:
  We show that geometric theories with $p$-form gauge fields have a
nonassociative symmetry structure, extending an underlying Lie algebra. This
nonassociativity is controlled by the same Chevalley-Eilenberg cohomology that
classifies free differential algebras, $p$-form generalizations of
Cartan-Maurer equations. A possible relation with flux backgrounds of closed
string theory is pointed out.


title: Orientation Parameters of the Cepheid System in the Galaxy

abstract:
  Based on the distribution of long-period Cepheids, we have redetermined the
orientation parameters of their principal plane in the Galaxy. Based on 299
Cepheids with heliocentric distances $r<20$ kpc and pulsation periods
$P\geq5^d$, we have found the directions of the three principal axes of the
position ellipsoid:
  $L_1=281.0\pm0.1^\circ,$ $B_1=-1.9\pm0.1^\circ,$
  $L_2= 11.0\pm0.7^\circ,$ $B_2=0.2\pm0.1^\circ$ and
  $L_3=275.9\pm0.7^\circ,$ $B_3=88.1\pm0.1^\circ$. Thus, the line of nodes
$l_\Omega=L_3+90^\circ=5.9^\circ$ is very close to the direction to the
Galactic center; the Cepheid symmetry plane is inclined to the Galactic plane
approximately by $-2^\circ$ in the direction of the first axis ($L_1$). The
direction of the line of nodes found from old Cepheids ($P<5^d$) differs
significantly and is $l_\Omega=298^\circ$. The elevation of the Sun above the
Galactic plane has been estimated from 365 closer stars ($r<4$ kpc) without any
constraint on the pulsation period to be $h_\odot=23\pm5$ pc.


title: Cepheid Kinematics and the Galactic Warp

abstract:
  The space velocities of 200 long-period ($P>5$ days) classical Cepheids with
known proper motions and line-of-sight velocities whose distances were
estimated from the period--luminosity relation have been analyzed. The linear
Ogorodnikov-Milne model has been applied, with the Galactic rotation having
been excluded from the observed velocities in advance. Two significant
gradients have been found in the Cepheid velocities,
  $\partial W/\partial Y=-2.1\pm0.7$ km s$^{-1}$ kpc$^{-1}$ and
  $\partial V/\partial Z= 27\pm10 $ km s$^{-1}$ kpc$^{-1}$.
  In such a case, the angular velocity of solid-body rotation around the
Galactic $X$ axis directed to the Galactic center is $-15\pm5$ km s$^{-1}$
kpc$^{-1}$.


title:
The power-law reaction rate coefficient for an elementary bimolecular
  reaction

abstract:
  The power-law TST reaction rate coefficient for an elementary bimolecular
reaction is studied when the reaction takes place in a nonequilibrium system
with power-law distributions. We derive a generalized TST rate coefficient,
which not only depends on a power-law parameter but also on the reaction
coordinate frequency of transition state. The numerical analyses show a very
strong dependence of TST rate coefficient on the power-law parameter, and
clearly indicate that a tiny deviation from unity in the parameter (thus from
the Boltzmann-Gibbs distribution) would result in significant changes in the
rate coefficient. We take an elementary F+H2 reaction as an application example
to calculate the reaction rate coefficient, and yield the rate values being
exactly agreement with the measurement values in all the experimental studies
in temperature range 190~765K.


title:
Galactic Rotation Curve and Spiral Density Wave Parameters from 73
  Masers

abstract:
  Based on kinematic data on masers with known trigonometric parallaxes and
measurements of the velocities of HI clouds at tangential points in the inner
Galaxy, we have refined the parameters of the Allen-Santillan model Galactic
potential and constructed the Galactic rotation curve in a wide range of
Galactocentric distances, from 0 to 20 kpc. The circular rotation velocity of
the Sun for the adopted Galactocentric distance $R_0=8$ kpc is $V_0=239\pm16$
km s$^{-1}$. We have obtained the series of residual tangential, $\Delta
V_{\theta}$, and radial, $\Delta V_R,$ velocities for 73 masers. Based on these
series, we have determined the parameters of the Galactic spiral density wave
satisfying the linear Lin.Shu model using the method of periodogram analysis
that we proposed previously. The tangential and radial perturbation amplitudes
are $f_\theta=7.0\pm1.2$ km s$^{-1}$ and $f_R=7.8\pm0.7$ km s$^{-1}$,
respectively, the perturbation wavelength is $\lambda=2.3\pm0.4$ kpc, and the
pitch angle of the spiral pattern in a two-armed model is
$i=-5.2^\circ\pm0.7^\circ$. The phase of the Sun $\chi_\odot$ in the spiral
density wave is $-50^\circ\pm15^\circ$ and $-160^\circ\pm15^\circ$ from the
residual tangential and radial velocities, respectively.


title: Beyond Expansion IV: Traces of Thin Semigroups

abstract:
  We continue our study of particular instances of the Affine Sieve, producing
levels of distribution beyond those attainable from expansion alone. Motivated
by McMullen's Arithmetic Chaos Conjecture regarding low-lying closed geodesics
on the modular surface defined over a given number field, we study the set of
traces for certain sub-semi-groups of SL2(Z) corresponding to absolutely
Diophantine numbers. In particular, we are concerned with the level of
distribution for this set. While the standard Affine Sieve procedure, combined
with Bourgain-Gamburd-Sarnak's resonance-free region for the resolvent of a
"congruence" transfer operator, produces some exponent of distribution alpha >
0, we are able to produce the exponent alpha < 1/3. This recovers
unconditionally the same exponent as what one would obtain under a
Ramanujan-type conjecture for thin groups. A key ingredient, of independent
interest, is a bound on the additive energy of SL2(Z).


title:
The mean first passage time in an energy-diffusion controlled regime
  with power-law distributions

abstract:
  Based on the mean first passage time (MFPT) theory, we derive the expression
of the MFPT in the energy-diffusion controlled regime with a power-law
distribution. We discuss the finite barrier effect (i.e. thermal energy is not
small with respect to the potential barrier) and compare it with the Kramers
infinite barrier result both in the power-law distribution and in a
Maxwell-Boltzmann distribution. It is shown that the MFPT with the power-law
distribution extends the Kramers' low damping result to the relatively low
barrier. We pay attention to the energy-diffusion controlled regime which is of
great interest in the context of Josephson junctions, and study how the
power-law parameter affects the current distribution function in the experiment
of Josephson junctions.


title:
Approximate next-to-next-to-leading order corrections to hadronic jet
  production

abstract:
  We determine dominant next-to-next-to-leading order QCD corrections to
single-inclusive jet production at the LHC and Tevatron, using the established
threshold resummation framework. In contrast to previous literature on this
topic, our study incorporates all of the following features: (1) It properly
accounts for the way a jet is defined in experiment and treated in available
full next-to-leading order calculations, (2) It includes the three leading
classes of logarithmic terms in the perturbative expansion, and (3) It is
adapted to the full kinematics in jet transverse momentum and rapidity relevant
for experiments. A recent full next-to-next-to-leading order calculation in the
purely gluonic channel allows us to assess the region where our approximate
corrections provide an accurate description. We expect our results to be
important on the way to precision jet phenomenology at the LHC and as benchmark
for further full next-to-next-to-leading order calculations.


title: Spectral correspondences for affine Hecke algebras

abstract:
  We introduce the notion of spectral transfer morphisms between normalized
affine Hecke algebras, and show that such morphisms induce spectral measure
preserving correspondences on the level of the tempered spectra of the affine
Hecke algebras involved. We define a partial ordering on the set of isomorphism
classes of normalized affine Hecke algebras, which plays an important role for
the Langlands parameters of Lusztig's unipotent representations.


title:
Reevaluation of the Prospect of Observing Neutrinos from Galactic
  Sources in the Light of Recent Results in Gamma Ray and Neutrino Astronomy

abstract:
  In light of the recent IceCube evidence for a flux of extraterrestrial
neutrinos, we revisit the prospect of observing the sources of the Galactic
cosmic rays. In particular, we update the predictions for the neutrino flux
expected from sources in the nearby star-forming region in Cygnus taking into
account recent TeV gamma ray measurements of their spectra. We consider the
three Milagro sources: MGRO J2019+37, MGRO J1908+06 and MGRO J2031+41 and
calculate the attainable confidence level limits and statistical significance
as a function of the exposure time. We also evaluate the prospects for a
kilometer-scale detector in the Mediterranean to observe and elucidate the
origin of the cosmic neutrino flux measured by IceCube.


title: On the values of the functions zeta and gamma

abstract:
  An analysis of the zeta and gamma function is presented, using elementary
functions like [] and {}, a general formula for the angle of zeta(1/2 + i*n) is
found and the same for the gamma function.


title:
A Simple Viscometer for High School and First Years Undergraduate
  Program Students: Theory and Experiment

abstract:
  A simple viscometer consists of mineral water bottle and trink straw is used
to predict vicosity of water. A model is derived from Bernoulli's principle and
Poiseulli's law. Value about 0.374 - 0.707 cP is obtained for observation in
room temperature. About 10 minutes of observation time is needed to get the
data.
  Keywords: equation of continuity, Bernoulli's equation, viscosity
coefficient, Poiseulli flow.


title:
Weak Visibility Queries of Line Segments in Simple Polygons and
  Polygonal Domains

abstract:
  In this paper we consider the problem of computing the weak visibility
polygon of any query line segment $pq$ (or $WVP(pq)$) inside a given polygon
$P$. Our first non-trivial algorithm runs in simple polygons and needs $O(n^3
\log n)$ time and $O(n^3)$ space in the preprocessing phase to report $WVP(pq)$
of any query line segment $pq$ in time $O(\log n + |WVP(pq)|)$. We also give an
algorithm to compute the weak visibility polygon of a query line segment in a
non-simple polygon with $h$ pairwise-disjoint polygonal obstacles with a total
of $n$ vertices. Our algorithm needs $O(n^2 \log n)$ time and $O(n^2)$ space in
the preprocessing phase and computes $WVP(pq)$ in query time of $O(n\hbar \log
n + k)$, in which $\hbar$ is an output sensitive parameter of at most
$\min(h,k)$, and $k = O(n^2h^2)$ is the output size. This is the best
query-time result on this problem so far.


title:
Anti-rumor dynamics and emergence of the timing threshold on complex
  network

abstract:
  Anti-rumor dynamics is proposed on the basis of rumor dynamics and the
characteristics of anti-rumor dynamics are explored by both mean-field
equations and numerical simulations on complex network. The main metrics we
study are the timing effect of combating rumor and the identification of
influential nodes, which are what an efficient strategy against rumor may
concern about. The results indicate that, there exists robust time dependence
of anti-rumor dynamics and the timing threshold emerges as a consequence of
launching the anti-rumor at different delay time after the beginning of rumor
spreading. The timing threshold as a critical feature is further verified on a
series of Barabasi-Albert scale-free networks (BA networks), where anti-rumor
dynamics arises explicitly. The timing threshold is a network-dependent
quantity and its value decreases as the average degree of the BA network
increases until close to zero. Meanwhile, coreness also constitutes a better
topological descriptor to identify hubs. Our results will hopefully be useful
for the understanding of spreading behaviors of rumor and anti-rumor and
suggest a possible avenue for further study of interplays of multiple pieces of
information on complex network.


title:
De coherence for a heavy particle interacting with a light one: new
  analysis and numerics

abstract:
  We study the dynamics of a quantum heavy particle undergoing a repulsive
interaction with a light one. The main motivation is the detailed description
of the loss of coherence induced on a quantum system (in our model, the heavy
particle) by the interaction with the environment (the light particle). The
content of the paper is analytical and numerical. Concerning the analytical
contribution, we show that an approximate description of the dynamics of the
heavy particle can be carried out in two steps: first comes the interaction,
then the free evolution. In particular, all effects of the interaction can be
embodied in the action of a collision operator that acts on the initial state
of the heavy particle. With respect to previous analytical results on the same
topics, we turn our focus from the M{\o}ller wave operator to the full
scattering operator, whose analysis proves to be simpler. Concerning the
numerical contribution, we exploit the previous analysis to construct an
efficient numerical scheme that turns the original, multiscale, two-body
problem in two one-body problems which can be solved separately. This leads to
a considerable gain in simulation time. We present and interpret some
simulations carried out on specific one-dimensional systems by using the new
scheme. Finally, we propose a new description of the mechanism of decoherence
induced by scattering: decoherence is produced by an interference-free bump
which arises from the initial state of the heavy particle immediately after the
collision. We support such a picture by numerical evidence as well as by an
approximation theorem.


title: Particle acceleration by Majumdar-Papapetrou di-hole

abstract:
  We explore the multi-black hole spacetimes from the perspective of the
ultra-high energy particle collisions. Such a discussion is limited to the
spacetimes containing a single black hole so far. We deal with the
Majumdar-Papapetrou solution representing a system consisting of two identical
black holes in the equilibrium. In order to identify the conditions suitable
for the process of high energy collisions, we consider particles confined to
move on the equatorial plane towards the axis of symmetry with the zero angular
momentum. We consider collision between the particles moving in opposite
directions at the location midway between the black holes on the axis. We show
that the center of mass energy of collision between the particles increases
with the decrease in the separation between the black holes and shows
divergence in the limit where the separation goes to zero. We estimate the size
of the region close to the central point on the equatorial plane where it would
be possible to have high energy collisions and show that this region has a
reasonably large spatial extent. We further explore the process of high energy
collisions with the general geodesics with arbitrary angular momentum on the
equatorial plane away from the central point. Although in this paper we deal
with theMajumdar-Papapetrou spacetime which serves as a toy example
representing multiple black holes, we speculate on the possibility that the
ultra-high energy collisions would also occur in the more general setting like
colliding black holes, when distance between the black holes is extremely
small, which can in principle be verified in the numerical relativity
simulations.


title:
Measurements of indirect CP asymmetries in $D^0\to K^-K^+$ and
  $D^0\to\pi^-\pi^+$ decays

abstract:
  A study of indirect CP violation in $D^0$ mesons through the determination of
the parameter $A_\Gamma$ is presented using a data sample of $pp$ collisions,
corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected with the
LHCb detector and recorded at the centre-of-mass energy of 7 TeV at the LHC.
The parameter $A_\Gamma$ is the asymmetry of the effective lifetimes measured
in decays of $D^0$ and $\bar{D}^0$ mesons to the CP eigenstates $K^-K^+$ and
$\pi^-\pi^+$. Fits to the data sample yield
$A_\Gamma(KK)=(-0.35\pm0.62\pm0.12)\times 10^{-3}$ and
$A_\Gamma(\pi\pi)=(0.33\pm1.06\pm0.14)\times 10^{-3}$, where the first
uncertainties are statistical and the second systematic. The results represent
the world's best measurements of these quantities. They show no difference in
$A_\Gamma$ between the two final states and no indication of CP violation.


title: Randomized LU Decomposition

abstract:
  We present a fast randomized algorithm that computes a low rank LU
decomposition. Our algorithm uses random projections type techniques to
efficiently compute a low rank approximation of large matrices. The randomized
LU algorithm can be parallelized and further accelerated by using sparse random
matrices in its projection step. Several different error bounds are proven for
the algorithm approximations. To prove these bounds, recent results from random
matrix theory related to subgaussian matrices are used. As an application, we
also show how the algorithm can be utilized to solve problems such as the
rank-deficient least squares problem. Numerical examples, which illustrate the
performance of the algorithm and compare it to other decomposition methods, are
presented.


title: Symmetry Energy from Holographic QCD

abstract:
  We review the symmetry energy in the context of AdS/CFT correspondence. After
constructing $D$ brane configurations corresponding to dense system in boundary
theory, we calculate the symmetry energy by solving DBI action of $D$ branes in
confining and deconfining phase. We conclude the density dependence of the
symmetry energy has scaling law whose power depends only on dimensionality of
the branes and space-time.


title: Semiarcs with long secants

abstract:
  In a projective plane $\Pi_q$ of order $q$, a non-empty point set ${\cal
S}_t$ is a $t$-semiarc if the number of tangent lines to ${\cal S}_t$ at each
of its points is $t$. If ${\cal S}_t$ is a $t$-semiarc in $\Pi_q$, $t<q$, then
each line intersects ${\cal S}_t$ in at most $q+1-t$ points. Dover proved that
semiovals (semiarcs with $t=1$) containing $q$ collinear points exist in
$\Pi_q$ only if $q<3$. We show that if $t>1$, then $t$-semiarcs with $q+1-t$
collinear points exist only if $t\geq \sqrt{q-1}$. In $\mathrm{PG}(2,q)$ we
prove the lower bound $t\geq(q-1)/2$, with equality only if ${\cal S}_t$ is a
blocking set of R\'edei type of size $3(q+1)/2$.
  We call the symmetric difference of two lines, with $t$ further points
removed from each line, a $V_t$-configuration. We give conditions ensuring a
$t$-semiarc to contain a $V_t$-configuration and give the complete
characterization of such $t$-semiarcs in $\mathrm{PG}(2,q)$.


title: Algorithms for Timed Consistency Models

abstract:
  One of the major challenges in distributed systems is establishing
consistency among replicated data in a timely fashion. While the consistent
ordering of events has been extensively researched, the time span to reach a
consistent state is mostly considered an effect of the chosen consistency
model, rather than being considered a parameter itself. This paper argues that
it is possible to give guarantees on the timely consistency of an operation.
Subsequent to an update the cloud and all connected clients will either be
consistent with the update within the defined upper bound of time or the update
will be returned. This paper suggests the respective algorithms and protocols
capable of producing such comprehensive Timed Consistency, as conceptually
proposed by Torres-Rojas et al. The solution offers business customers an
increasing level of predictability and adjustability. The temporal certainty
concerning the execution makes the cloud a more attractive tool for
time-critical or mission-critical applications fearing the poor availability of
Strong Consistency in cloud environments.


title:
Spatial anisotropy and heterogeneity in contractility and adhesion
  distribution may contribute to cell steering during migration

abstract:
  Transition from random to persistent cell motility requires spatiotemporal
organization of the cytoskeleton and focal adhesions. The influence of these
two structures on cell steering can also be gleaned from trypsin de-adhesion
experiments, wherein cells exposed to trypsin round up, exhibiting a
combination of rotation and translation. Here, we present a model to evaluate
the contributions of contractility and bond distribution to experimentally
observed de-adhesion. We show that while asymmetry in bond distribution causes
only cell translation, a combination of asymmetric bond distribution and
non-uniform contractility are required for translation and rotation, and may
guide cell migration.


title: Semiarcs with a long secant in $\mathrm{PG}(2,q)$

abstract:
  A $t$-semiarc is a pointset ${\cal S}_t$ with the property that the number of
tangent lines to ${\cal S}_t$ at each of its points is $t$. We show that if a
small $t$-semiarc ${\cal S}_t$ in $\mathrm{PG}(2,q)$ has a large collinear
subset ${\cal K}$, then the tangents to ${\cal S}_t$ at the points of ${\cal
K}$ can be blocked by $t$ points not in ${\cal K}$. We also show that small
$t$-semiarcs are related to certain small blocking sets. Some characterization
theorems for small semiarcs with large collinear subsets in $\mathrm{PG}(2,q)$
are given.


title: Ramsey numbers of ordered graphs

abstract:
  An ordered graph is a pair $\mathcal{G}=(G,\prec)$ where $G$ is a graph and
$\prec$ is a total ordering of its vertices. The ordered Ramsey number
$\overline{R}(\mathcal{G})$ is the minimum number $N$ such that every ordered
complete graph with $N$ vertices and with edges colored by two colors contains
a monochromatic copy of $\mathcal{G}$.
  In contrast with the case of unordered graphs, we show that there are
arbitrarily large ordered matchings $\mathcal{M}_n$ on $n$ vertices for which
$\overline{R}(\mathcal{M}_n)$ is superpolynomial in $n$. This implies that
ordered Ramsey numbers of the same graph can grow superpolynomially in the size
of the graph in one ordering and remain linear in another ordering.
  We also prove that the ordered Ramsey number $\overline{R}(\mathcal{G})$ is
polynomial in the number of vertices of $\mathcal{G}$ if the bandwidth of
$\mathcal{G}$ is constant or if $\mathcal{G}$ is an ordered graph of constant
degeneracy and constant interval chromatic number. The first result gives a
positive answer to a question of Conlon, Fox, Lee, and Sudakov.
  For a few special classes of ordered paths, stars or matchings, we give
asymptotically tight bounds on their ordered Ramsey numbers. For so-called
monotone cycles we compute their ordered Ramsey numbers exactly. This result
implies exact formulas for geometric Ramsey numbers of cycles introduced by
K\'arolyi, Pach, T\'oth, and Valtr.


title: Weakly Smooth Structures in Gromov-Witten Theory

abstract:
  In order to establish Fredholm theory on stratified topological Banach
manifolds in Gromov-Witten theory, we have introduced flat structures on such
manifolds in [L4]. Such a structure is obtained from local flat coordinate
charts. The transformations between these charts are only continuous in
general. The purpose of this paper is two-fold : firstly to show that on the
topological Banach manifolds and bundles appeared in Gromov-Witten and Floer
type theories, there are enough smooth functions and sections viewed in any
admissible charts and trivializations; secondly to demonstrate some finer
aspects about the weakly smooth sections.


title:
Transitions between patterned states in vegetation models for semi-arid
  ecosystems

abstract:
  A feature common to many models of vegetation pattern formation in semi-arid
ecosystems is a sequence of qualitatively different patterned states, "gaps ->
labyrinth -> spots", that occurs as a parameter representing precipitation
decreases. We explore the robustness of this "standard" sequence in the generic
setting of a bifurcation problem on a hexagonal lattice, as well as in a
particular reaction-diffusion model for vegetation pattern formation.
Specifically, we consider a degeneracy of the bifurcation equations that
creates a small bubble in parameter space in which stable small-amplitude
patterned states may exist near two Turing bifurcations. Pattern transitions
between these bifurcation points can then be analyzed in a weakly nonlinear
framework. We find that a number of transition scenarios besides the standard
sequence are generically possible, which calls into question the reliability of
any particular pattern or sequence as a precursor to vegetation collapse.
Additionally, we find that clues to the robustness of the standard sequence lie
in the nonlinear details of a particular model.


title:
Small Area Estimation via Multivariate Fay-Herriot Models with Latent
  Spatial Dependence

abstract:
  The Fay-Herriot model is a standard model for direct survey estimators in
which the true quantity of interest, the superpopulation mean, is latent and
its estimation is improved through the use of auxiliary covariates. In the
context of small area estimation, these estimates can be further improved by
borrowing strength across spatial region or by considering multiple outcomes
simultaneously. We provide here two formulations to perform small area
estimation with Fay-Herriot models that include both multivariate outcomes and
latent spatial dependence. We consider two model formulations, one in which the
outcome-by-space dependence structure is separable and one that accounts for
the cross dependence through the use of a generalized multivariate conditional
autoregressive (GMCAR) structure. The GMCAR model is shown in a state-level
example to produce smaller mean square prediction errors, relative to
equivalent census variables, than the separable model and the state-of-the-art
multivariate model with unstructured dependence between outcomes and no spatial
dependence. In addition, both the GMCAR and the separable models give smaller
mean squared prediction error than the state-of-the-art model when conducting
small area estimation on county level data from the American Community Survey.


title: A new estimate of the difference among quasi-arithmetic means

abstract:
  In the 1960s Cargo and Shisha proved some majorizations for the distance
among quasi-arithmetic means (defined as f^{-1}(\sum_{i=1}^{n} w_i f(a_i) for
any continuous, strictly monotone function f:I->R, where I is an interval, and
a=(a_1,...,a_n) is a vector with entries in I, w=(w_1,...,w_n) is a sequence of
corresponding weights w_i>0, w_1+...+w_n=1).
  Nearly thirty years later, in 1991, P\`ales presented an iff condition for a
sequence of quasi-arithmetic means to converge to another QA mean. It was
closely related with the three parameters' operator (f(x)-f(z))/(f(x)-f(y)).
  The author presented recently an estimate for the distance among such
quasi-arithmetic means whose underlying functions satisfy some smoothness
conditions. Used was the operator f -> f''/f' introduced in the 1940s by
Mikusi\'nski and \L{}ojasiewicz. It is natural to look for similar estimate(s)
in the case of the underlying functions not being smooth. For instance, by the
way of using P\`ales' operator. This is done in the present note. Moreover, the
result strengthens author's earlier estimates.


title: Tunable polarization in beam-splitter based on 2D topological insulators

abstract:
  The typical bulk model describing 2D topological insulators (TI) consists of
two types of spin-orbit terms, the so-called Dirac term which induces out-of
plane spin polarization and the Rashba term which induces in-plane spin
polarization. We show that for some parameters of the Fermi energy, the beam
splitter device built on 2D TIs can achieve higher in-plane spin polarization
than one built on materials described by the Rashba model itself. Further, due
to high tunability of the electron density and the asymmetry of the quantum
well, spin polarization in different directions can be obtained. While in the
normal (topologically trivial) regime the in-plane spin polarization would
dominate, in the inverted regime the out-of-plane polarization is more
significant not only in the band gap but also for small Fermi energies above
the gap. Further, we suggest a double beam splitter scheme, to measure in-plane
spin current all electrically. Although we consider here as an example
HgTe/CdTe quantum wells, this scheme could be also promising for InAs/GaSb QWs
where the in- and out-of-plane polarization could be achieved in a single
device.


title:
From the Poincar\'e Theorem to generators of the unit group of integral
  group rings of finite groups

abstract:
  We give an algorithm to determine finitely many generators for a subgroup of
finite index in the unit group of an integral group ring $\mathbb{Z} G$ of a
finite nilpotent group $G$, this provided the rational group algebra
$\mathbb{Q} G$ does not have simple components that are division classical
quaternion algebras or two-by-two matrices over a classical quaternion algebra
with centre $\mathbb{Q}$. The main difficulty is to deal with orders in
quaternion algebras over the rationals or a quadratic imaginary extension of
the rationals. In order to deal with these we give a finite and easy
implementable algorithm to compute a fundamental domain in the hyperbolic three
space $\mathbb{H}^3$ (respectively hyperbolic two space $\mathbb{H}^2$) for a
discrete subgroup of ${\rm PSL}_2(\mathbb{C})$ (respectively ${\rm
PSL}_2(\mathbb{R})$) of finite covolume. Our results on group rings are a
continuation of earlier work of Ritter and Sehgal, Jespers and Leal.


title:
Linear and synchrosqueezed time-frequency representations revisited.
  Part I: Overview, standards of use, related issues and algorithms

abstract:
  Time-frequency representations (TFRs) of signals, such as the windowed
Fourier transform (WFT), wavelet transform (WT) and their synchrosqueezed
variants (SWFT, SWT), provide powerful analysis tools. However, there are many
important issues related to the practical use of TFRs that need to be
clarified. Here we present a thorough review of these TFRs, summarizing all
theoretical, practical and numerical aspects of their use, reconsidering some
conventions and introducing new concepts and procedures. The purposes of this
work are: (i) to provide a consistent overview of the computation, properties,
and use of the (S)WFT/(S)WT methods; (ii) to establish general standards
related to their use, both theoretical and practical; and (iii) to provide
clean and optimized algorithms and MatLab codes, appropriate for any window or
wavelet.


title:
Measurement of 7p$_{1/2}$-state hyperfine structure and
  7s$_{1/2}$-7p$_{1/2}$ transition isotope shift in $^{203}$Tl and $^{205}$Tl

abstract:
  A two-step, two-color laser spectroscopy technique has been used to measure
the hyperfine splitting of the 7p$_{1/2}$ excited state in $^{203}$Tl and
$^{205}$Tl, as well as the isotope shift within the 7s$_{1/2}$ - 7p$_{1/2}$
transition. Our measured values for the hyperfine splittings, 2153.2(7) MHz (in
$^{203}$Tl) and 2173.3(8) MHz (in $^{205}$Tl), each differ by 20 MHz from
previously published values which quoted comparable precision. The transition
isotope shift of $^{203}$Tl relative to $^{205}$Tl was measured to be 534.4(9)
MHz. In our experiment, one laser was locked to the thallium ground-state
6p$_{1/2}$ - 7s$_{1/2}$ 378 nm transition, while the second, spatially
overlapping laser was scanned across the 7s$_{1/2}$(F=1) - 7p$_{1/2}$(F=0,1)
hyperfine transitions. To facilitate accurate frequency calibration,
radio-frequency modulation of the laser was used to create sidebands in the
absorption spectrum.


title: Compressed Sensing SAR Imaging with Multilook Processing

abstract:
  Multilook processing is a widely used speckle reduction approach in synthetic
aperture radar (SAR) imaging. Conventionally, it is achieved by incoherently
summing of some independent low-resolution images formulated from overlapping
subbands of the SAR signal. However, in the context of compressive sensing (CS)
SAR imaging, where the samples are collected at sub-Nyquist rate, the data
spectrum is highly aliased that hinders the direct application of the existing
multilook techniques. In this letter, we propose a new CS-SAR imaging method
that can realize multilook processing simultaneously during image
reconstruction. The main idea is to replace the SAR observation matrix by the
inverse of multilook procedures, which is then combined with random sampling
matrix to yield a multilook CS-SAR observation model. Then a joint sparse
regularization model, considering pixel dependency of subimages, is derived to
form multilook images. The suggested SAR imaging method can not only
reconstruct sparse scene efficiently below Nyquist rate, but is also able to
achieve a comparable reduction of speckles during reconstruction. Simulation
results are finally provided to demonstrate the effectiveness of the proposed
method.


title: A comparison of evolutionary tracks for single Galactic massive stars

abstract:
  In this paper, we compare the currently available evolutionary tracks for
Galactic massive stars. Our main goal is to highlight the uncertainties on the
predicted evolutionary paths. We compute stellar evolution models with the
codes MESA and STAREVOL. We compare our results with those of four published
grids of massive stellar evolution models (Geneva, STERN, Padova and FRANEC
codes). We first investigate the effects of overshooting, mass loss,
metallicity, chemical composition. We subsequently focus on rotation. Finally,
we compare the predictions of published evolutionary models with the observed
properties of a large sample of Galactic stars. We find that all models agree
well for the main sequence evolution. Large differences in luminosity and
temperatures appear for the post main sequence evolution, especially in the
cool part of the HR diagram. Depending on the physical ingredients, tracks of
different initial masses can overlap, rendering any mass estimate doubtful. For
masses between 7 and 20 Msun, we find that the main sequence width is slightly
too narrow in the Geneva models including rotation. It is (much) too wide for
the (STERN) FRANEC models. This conclusion is reached from the investigation of
the HR diagram and from the evolution of the surface velocity as a function of
surface gravity. An overshooting parameter alpha between 0.1 and 0.2 in models
with rotation is preferred to reproduce the main sequence width. Determinations
of surface abundances of carbon and nitrogen are partly inconsistent and cannot
be used at present to discriminate between the predictions of published tracks.
For stars with initial masses larger than about 60 Msun, the FRANEC models with
rotation can reproduce the observations of luminous O supergiants and WNh
stars, while the Geneva models remain too hot.


title: On the spectrum of shear flows and uniform ergodic theorems

abstract:
  The spectra of parallel flows (that is, flows governed by first-order
differential operators parallel to one direction) are investigated, on both
$L^2$ spaces and weighted-$L^2$ spaces. As a consequence, an example of a flow
admitting a purely singular continuous spectrum is provided. For flows
admitting more regular spectra the density of states is analyzed, and spaces on
which it is uniformly bounded are identified. As an application, an ergodic
theorem with uniform convergence is proved.


title:
On the Cauchy problem for the homogeneous Boltzmann-Nordheim equation
  for bosons: local existence, uniqueness and creation of moments

abstract:
  The Boltzmann-Nordheim equation is a modification of the Boltzmann equation,
based on physical considerations, that describes the dynamics of the
distribution of particles in a quantum gas composed of bosons or fermions. In
this work we investigate the Cauchy theory of the spatially homogeneous
Boltzmann-Nordheim equation for bosons, in dimension $d\geq 3$. We show
existence and uniqueness locally in time for any initial data in
$L^\infty\left(1+|v|^s\right)$ with finite mass and energy, for a suitable $s$,
as well as the instantaneous creation of moments of all order.


title:
Temporal Evolution of Sunspot Areas and Estimation of Related Plasma
  Flows

abstract:
  The increased amount of information provided by ongoing missions such as the
Solar Dynamics Observatory (SDO) represents a great challenge for the
understanding of basic questions such as the internal structure of sunspots and
how they evolve with time. Here, we contribute with the exploitation of new
data, to provide a better understanding of the separate growth and decay of
sunspots, umbra and penumbra. Using fuzzy sets to compute separately the areas
of sunspot umbra and penumbra, the growth and decay rates for active regions
NOAA 11117, NOAA 11428, NOAA 11429, and NOAA 11430 are computed, from the
analysis of intensitygrams obtained by the Helioseismic and Magnetic Imager
onboard SDO. A simplified numerical model is proposed for the decay phase,
whereby an empirical irrotational and uniformly convergent horizontal velocity
field interacting with an axially symmetric and height invariant magnetic
field, reproduces the large-scale features of the much more complex convection
observed inside sunspots.


title: A left topological monoid associated to a topological groupoid

abstract:
  This paper presents a fanctor $S$ from the category of groupoids to the
category of semigroups. Indeed, a monoid $S_G$ with a right zero element is
related to a topological groupoid $G$. The monoid $S_G$ is a subset of
$C(G,G)$, the set of all continuous functions from $G$ to $G$, and with the
compact- open topology inherited from C(G,G) is a left topological monoid. The
group of units of $S_G$, which is denoted by $H(1)$, is isomorphic to a
subgroup of the group of all bijection map from $G$ to $G$ under composition of
functions. Moreover, it is proved that $H(1)$ is embedded in the group of all
invertible linear operators on $C(G)$, the set of all complex continuous
function on $G$.


title: Rotating Boson Stars in Einstein-Gauss-Bonnet gravity

abstract:
  A self-interacting SU(2)-doublet of complex scalar fields, minimally coupled
to Einstein-Gauss-Bonnet gravity is considered in five space-time dimensions.
The classical equations admit two families of solitons corresponding to
spinning and non-spinning bosons stars. The generic solutions are constructed
numerically and agree with exact results that are available in special limits
of the parameters. The pattern of the boson stars is shown to be qualitatively
affected by the Gauss-Bonnet coupling constant.


title: Configuration space integrals and the topology of knot and link spaces

abstract:
  This article surveys the use of configuration space integrals in the study of
the topology of knot and link spaces. The main focus is the exposition of how
these integrals produce finite type invariants of classical knots and links.
More generally, we also explain the construction of a chain map, given by
configuration space integrals, between a certain diagram complex and the deRham
complex of the space of knots in dimension four or more. A generalization to
spaces of links, homotopy links, and braids is also treated, as are connections
to Milnor invariants, manifold calculus of functors, and the rational formality
of the little balls operads.


title:
Conditional solvation of isoleucine in model extended and helical
  peptides: context dependence of hydrophobic hydration and the failure of the
  group-transfer model

abstract:
  The hydration thermodynamics of the GXG tripeptide relative to the reference
GGG is often used to define the conditional hydration contribution of X. This
quantity or the hydration thermodynamics of a small molecule analog of the
side-chain or some combination of such estimates, have anchored the
interpretation of seminal experiments on protein stability and folding. We show
that such procedures to model protein hydration have significant limitations.
We study the conditional hydration thermodynamics of the isoleucine side-chain
in an extended pentapeptide and in helical deca-peptides, using as appropriate
an extended penta-glycine or appropriate helical deca-peptides as reference.
Hydration of butane in the gauche conformation provides a small molecule
reference for the side-chain. We use the quasichemical theory to parse the
hydration thermodynamics into chemical, packing, and long-range interaction
contributions. The chemical contribution reflects the contribution of solvent
clustering within the defined inner-shell of the solute; the chemical
contribution of g-butane is substantially more negative than the conditional
chemical contribution of isoleucine. The packing contribution gives the work
required to create a cavity in the solvent, a quantity of interest in
understanding hydrophobic hydration. The packing contribution for g-butane
substantially overestimates the conditional packing of isoleucine. The net of
such compensating contributions still disagrees with the conditional free
energy of isoleucine but by a lesser magnitude. The excess enthalpy and entropy
of hydration of g-butane model are also more negative than the corresponding
conditional quantities for the side-chain. The conditional solvation of
isoleucine in GGIGG also proves unsatisfactory in describing the conditional
solvation of isoleucine in the helical peptides.


title:
ProbMetab: an R package for Bayesian probabilistic annotation of LC-MS
  based metabolomics

abstract:
  We present ProbMetab, an R package which promotes substantial improvement in
automatic probabilistic LC-MS based metabolome annotation. The inference engine
core is based on a Bayesian model implemented to: (i) allow diverse source of
experimental data and metadata to be systematically incorporated into the model
with alternative ways to calculate the likelihood function and; (ii) allow
sensitive selection of biologically meaningful biochemical reactions databases
as Dirichlet-categorical prior distribution. Additionally, to ensure result
interpretation by system biologists, we display the annotation in a network
where observed mass peaks are connected if their candidate metabolites are
substrate/product of known biochemical reactions. This graph can be overlaid
with other graph-based analysis, such as partial correlation networks, in a
visualization scheme exported to Cytoscape, with web and stand alone versions.
ProbMetab was implemented in a modular fashion to fit together with established
upstream (xcms, CAMERA, AStream, mzMatch.R, etc) and downstream R package tools
(GeneNet, RCytoscape, DiffCorr, etc). ProbMetab, along with extensive
documentation and case studies, is freely available under GNU license at:
http://labpib.fmrp.usp.br/methods/probmetab/.


title: A New Look at Open Cluster NGC 6520

abstract:
  We use CCD and photoelectric photometry with Stromgren filters along with
medium resolution spectra to investigate NGC 6520, an open cluster very nearly
in the direction of the galactic center. We find an age of 60 Myr, a distance
of 2 kpc, and an average reddening E(b-y) = 0.295, but which increases toward
the south. The average heliocentric radial velocity of the B stars is -29
km/sec, while the velocity of the nearby Barnard 86 is about 0 (heliocentric,
-11 km/sec compared to the LSR). This velocity difference amounts to about 1.8
kpc since the cluster formed, implying that it is extremely doubtful NGC 6520
is related to Barnard 86.


title:
Intermodal Energy Transfer in a Tapered Optical Fiber: Optimizing
  Transmission

abstract:
  We present an experimental and theoretical study of the energy transfer
between modes during the tapering process of an optical nanofiber through
spectrogram analysis. The results allow optimization of the tapering process,
and we measure transmission in excess of 99.95% for the fundamental mode. We
quantify the adiabaticity condition through calculations and place an upper
bound on the amount of energy transferred to other modes at each step of the
tapering, giving practical limits to the tapering angle.


title: Loss of non-Gaussianity for damped photon-subtracted thermal states

abstract:
  We investigate non-Gaussianity properties for a set of classical one-mode
states obtained by subtracting photons from a thermal state. Three
distance-type degrees of non-Gaussianity used for these states are shown to
have a monotonic behaviour with respect to their mean photon number. Decaying
of their non-Gaussianity under damping is found to be consistently described by
the distance-type measures considered here. We also compare the dissipative
evolution of non-Gaussianity when starting from $M$-photon-subtracted and
$M$-photon-added thermal states


title:
The "Life Potential": a new complex algorithm to assess "Heart Rate
  Variability" from Holter records for cognitive and diagnostic aims.
  Preliminary experimental results showing its dependence on age, gender and
  health conditions

abstract:
  Although HRV (Heart Rate Variability) analyses have been carried out for
several decades, several limiting factors still make these analyses useless
from a clinical point of view. The present paper aims at overcoming some of
these limits by introducing the "Life Potential" (BMP), a new mathematical
algorithm which seems to exhibit surprising cognitive and predictive
capabilities. BMP is defined as a linear combination of five HRV Non-Linear
Variables, in turn derived from the thermodynamic formalism of chaotic dynamic
systems. The paper presents experimental measurements of BMP (Average Values
and Standard Deviations) derived from 1048 Holter tests, matched in age and
gender, including a control group of 356 healthy subjects. The main results
are: (a) BMP always decreases when the age increases, and its dependence on age
and gender is well established; (b) the shape of the age dependence within
"healthy people" is different from that found in the general group: this
behavior provides evidence of possible illness, and seems to justify the
attribute of "life potential". A simplified "standard" procedure is then
supplied to compute BMP values for a given subject, whereas BMP dependence on
clinical status is now under investigation to make BMP a useful clinical tool.


title: Redshift drift in varying speed of light cosmology

abstract:
  We derive a redshift drift formula within the framework of varying speed of
light (VSL) theory using the specific ansatz for the variability of $c(t) = c_0
a^n(t)$. We show that negative values of the parameter $n$, which correspond to
diminishing value of the speed of light during the evolution of the universe,
effectively rescales dust matter to become little negative pressure matter, and
the cosmological constant to became phantom. Positive values of $n$ (growing
$c(t)$) make VSL model to become more like Cold Dark Matter (CDM) model.
Observationally, there is a distinction between the VSL model and the
$\Lambda$CDM model for the admissible values of the parameter $n \sim -
10^{-5}$, though it will be rather difficult to detect by planned extremely
large telescopes (E-ELT, TMT, GMT) within their accuracy.


title: Maximizing Revenues for Online-Dial-a-Ride

abstract:
  In the classic Dial-a-Ride Problem, a server travels in some metric space to
serve requests for rides. Each request has a source, destination, and release
time. We study a variation of this problem where each request also has a
revenue that is earned if the request is satisfied. The goal is to serve
requests within a time limit such that the total revenue is maximized. We first
prove that the version of this problem where edges in the input graph have
varying weights is NP-complete. We also prove that no algorithm can be
competitive for this problem. We therefore consider the version where edges in
the graph have unit weight and develop a 2-competitive algorithm for this
problem.


title: Noncommutative Chern-Simons theory on the quantum 3-sphere $S^3_\theta$

abstract:
  We consider the $\theta$-deformed quantum three sphere $S^3_\theta$ and study
its Chern--Simons theory from a spectral point of view. We first construct a
spectral triple on $S^3_\theta$ as a generalization of the Dirac geometry on
$S^3 $. Since the choice of Dirac operator is not unique, we give two more
natural spectral triples on $S^3_\theta$ related to the standard round metric.
We then compute the Chern--Simons action with respect to the three spectral
triples, it turns out that it is not a topological invariant, that is, it
depends on the choice of Dirac operators.


title:
A Spectral Study of the Linearized Boltzmann Equation for Diffusively
  Excited Granular Media

abstract:
  In this work, we are interested in the spectrum of the diffusively excited
granular gases equation, in a space inhomogeneous setting, linearized around an
homogeneous equilibrium.
  We perform a study which generalizes to a non-hilbertian setting and to the
inelastic case the seminal work of Ellis and Pinsky about the spectrum of the
linearized Boltzmann operator. We first give a precise localization of the
spectrum, which consists in an essential part lying on the left of the
imaginary axis and a discrete spectrum, which is also of nonnegative real part
for small values of the inelasticity parameter. We then give the so-called
inelastic "dispersion relations", and compute an expansion of the branches of
eigenvalues of the linear operator, for small Fourier (in space) frequencies
and small inelasticity.
  One of the main novelty in this work, apart from the study of the inelastic
case, is that we consider an exponentially weighted $L^1(m^{-1})$ Banach
setting instead of the classical $L^2(\mathcal M_{1,0,1}^{-1})$ Hilbertian
case, endorsed with Gaussian weights. We prove in particular that the results
of Ellis and Pinsky holds also in this space.


title: Fusion rules for the vertex operator algebra $V_{L_{2}}^{A_{4}}$

abstract:
  The fusion rules for vertex operator algebra $V_{L_{2}}^{A_{4}}$ are
determined.


title: A characterization of the vertex operator algebra $V_{L_{2}}^{A_{4}}$

abstract:
  The rational vertex operator algebra $V_{L_{2}}^{A_{4}}$ is characterized in
terms of weights of primary vectors. This reduces the classification of
rational vertex operator algebras with $c=1$ to the characterizations of
$V_{L_{2}}^{S_{4}}$ and $V_{L_{2}}^{A_{5}}.$


title: The High Altitude Water Cherenkov Observatory

abstract:
  The High Altitude Water Cherenkov (HAWC) observatory is a large field of
view, continuously operated, TeV gamma-ray experiment under construction at
4,100 m a.s.l. in Mexico. The HAWC observatory will have an order of magnitude
better sensitivity, angular resolution, and background rejection than its
predecessor, the Milagro experiment. The improved performance will allow us to
detect both transient and steady emissions, to study the Galactic diffuse
emission at TeV energies, and to measure or constrain the TeV spectra of GeV
gamma-ray sources. In addition, HAWC will be the only ground-based instrument
capable of detecting prompt emission from gamma-ray bursts above 50 GeV. The
HAWC observatory will consist of an array of 300 water Cherenkov detectors
(WCDs), each with four photomultiplier tubes. This array is currently under
construction on the flanks of the Sierra Negra volcano near the city of Puebla,
Mexico. The first thirty WCDs (forming an array approximately the size of
Milagro) were deployed in Summer 2012, and 100 WCDs will be taking data by May,
2013. We present in this paper the motivation for constructing the HAWC
observatory, the status of the deployment, and the first results from the
constantly growing array.


title: Discovery of a new kind of explosive X-ray transient near M86

abstract:
  We present the discovery of a new type of explosive X-ray flash in Chandra
images of the old elliptical galaxy M86. This unique event is characterised by
the peak luminosity of 6x10^42 erg/s for the distance of M86, the presence of
precursor events, the timescale between the precursors and the main event
(~4,000 s), the absence of detectable hard X-ray and gamma-ray emission, the
total duration of the event and the detection of a faint associated optical
signal. The transient is located close to M86 in the Virgo cluster at the
location where gas and stars are seen protruding from the galaxy probably due
to an ongoing wet minor merger. We discuss the possible mechanisms for the
transient and we conclude that the X-ray flash could have been caused by the
disruption of a compact white dwarf star by a ~10^4 Msun black hole.
Alternative scenarios such that of a foreground neutron star accreting an
asteroid or the detection of an off-axis (short) gamma-ray burst cannot be
excluded at present.


title: Quantum simulation of decoherence in optical waveguide lattices

abstract:
  We suggest that propagation of nonclassical light in lattices of optical
waveguides can provide a laboratory tool to simulate quantum decoherence
phenomena with high non-Markovian features. As examples, we study decoherence
of optical Schr\"{o}dinger cats in a lattice that mimics a dissipative quantum
harmonic oscillator coupled to a quantum bath, showing fractional decoherence
in the strong coupling regime, and Bloch oscillations of optical
Schr\"{o}dinger cats, where damped revivals of the coherence can be observed.


title:
Another Christoffel--Darboux Formula for Multiple Orthogonal Polynomials
  of Mixed Type

abstract:
  An alternative expression for the Christoffel--Darboux formula for multiple
orthogonal polynomials of mixed type is derived from the $LU$ factorization of
the moment matrix of a given measure and two sets of weights. We use the action
of the generalized Jacobi matrix $J$, also responsible for the recurrence
relations, on the linear forms and their duals to obtain the result.


title: On Jacobians of curves with superelliptic components

abstract:
  We investigate the decomposition of Jacobians of superelliptic curves based
on their automorphisms. For curve with equation $y^n=f(x^m)$ we provide an
necessary and sufficient condition in terms of $m$ and $n$ for the
decomposition of the Jacobian induced by the automorphisms of the curve.
Moreover, we generalize a construction in \cite{Ya} of a family of
non-hyperelliptic curves $\mathcal X_{r,s} $ and determine arithmetic
conditions on $r$ and $s$ that the Jacobians $\mbox{Jac} (\mathcal X_{r, s})$
decomposes.


title: Additive spectra of the 1/4 Cantor measure

abstract:
  In this paper, we add to the characterization of the Fourier spectra for
Bernoulli convolution measures. These measures are supported on Cantor subsets
of the line. We prove that performing an odd additive translation to half the
canonical spectrum for the 1/4 Cantor measure always yields an alternate
spectrum. We call this set an additive spectrum. The proof works by connecting
the additive set to a spectrum formed by odd multiplicative scaling.


title:
Exponential decay of solutions for the plate equation with localized
  damping

abstract:
  In this paper, we give positive answer to the open question raised in [E.
Zuazua, Exponential decay for the semilinear wave equation with localized
damping in unbounded domains. J. Math. Pures Appl., 70 (1991) 513--529] on the
exponential decay of solutions for the semilinear plate equation with localized
damping.


title:
Characterizing the Turbulent Properties of the Starless Molecular Cloud
  MBM16

abstract:
  We investigate turbulent properties of the non-star-forming, translucent
molecular cloud, MBM16 by applying the statistical technique of a
two-dimensional spatial power spectrum (SPS) on the neutral hydrogen (HI)
observations obtained by the Galactic Arecibo L-Band Feed Array HI (GALFA-HI)
survey. The SPS, calculated over the range of spatial scales from 0.1 to 17 pc,
is well represented with a single power-law function, with a slope ranging from
-3.3 to -3.7 and being consistent over the velocity range of MBM16 for a fixed
velocity channel thickness. However, the slope varies significantly with the
velocity slice thickness, suggesting that both velocity and density contribute
to HI intensity fluctuations. By using this variation we estimate the slope of
3D density fluctuations in MBM16 to be -3.7\pm0.2. This is significantly
steeper than what has been found for HI in the Milky Way plane, the Small
Magellanic Cloud, or the Magellanic Bridge, suggesting that interstellar
turbulence in MBM16 is driven on scales >17 pc and that the lack of stellar
feedback could be responsible for the steep power spectrum.


title:
Exact transition probabilities in the three-state Landau-Zener-Coulomb
  model

abstract:
  We obtain the exact expression for the matrix of nonadiabatic transition
probabilities in the model of three interacting states with a time-dependent
Hamiltonian. Unlike other known solvable Landau-Zener-like problems, our
solution is generally expressed in terms of hypergeometric functions that have
relatively complex behavior, e.g. the obtained transition probabilities may
show multiple oscillations as functions of parameters of the model Hamiltonian.

categories: quant-ph cond-mat.mes-hall math-ph math.MP


title:
Blue-phase templated fabrication of three-dimensional nanostructures for
  photonic applications

abstract:
  A promising approach to the fabrication of materials with nanoscale features
is the transfer of liquid-crystalline structure to polymers. However, this has
not been achieved in systems with full three-dimensional periodicity. Here we
demonstrate the fabrication of self-assembled three-dimensional nanostructures
by polymer templating blue phase I, a chiral liquid crystal with cubic
symmetry. Blue phase I was photopolymerized and the remaining liquid crystal
removed to create a porous free-standing cast which retains the chiral
three-dimensional structure of the blue phase, yet contains no chiral additive
molecules. The cast may in turn be used as a hard template for the fabrication
of new materials. By refilling the cast with an achiral nematic liquid crystal,
we created templated blue phases which have unprecedented thermal stability in
the range -125 to 125 [degrees symbol]C, and that act both as mirrorless lasers
and switchable electro-optic devices. Blue-phase templated materials will
facilitate advances in device architectures for photonics applications in
particular.


title:
Optimizing scanning strategies: Selecting scanning bandwidth in
  adversarial RF environments

abstract:
  In this paper we investigate the problem of designing a spectrum scanning
strategy to detect an intelligent Invader who wants to utilize spectrum
undetected for his/her unapproved purposes. To deal with this problem we apply
game-theoretical tools. We model the situation as a game between a Scanner and
an Invader where the Invader faces a dilemma: the more bandwidth the Invader
attempts to use leads to a larger payoff if he is not detected, but at the same
time also increases the probability of being detected and thus fined.
Similarly, the Scanner faces a dilemma: the wider the bandwidth scanned, the
higher the probability of detecting the Invader, but at the expense of
increasing the cost of building the scanning system. The equilibrium strategies
are found explicitly and reveal interesting properties. In particular, we have
found a discontinuous dependence of the equilibrium strategies on the network
parameters, fine and the type of the Invader's award. This discontinuity on
fine means that the network provider has to take into account a human factor
since some threshold values of fine could be very sensible for the Invader,
while in other situations simply increasing the fine has minimal deterrence
impact. Also we show how different reward types for the Invader (e.g. motivated
by using different type of application, say, video-streaming or downloading
files) can be incorporated into scanning strategy to increase its efficiency.


title: Basis entropy in Banach spaces

abstract:
  We introduce and study two notions of entropy in a Banach space X with a
normalized Schauder basis . The geometric entropy E(A) of a subset A of X is
defined to be the infimum of radii of compact bricks containing A. We obtain
several compactness characterizations for bricks (Theorem 3.7) useful for main
results. We also obtain sufficient conditions on a set in a Hilbert space to
have finite unconditional entropy. For Banach spaces without a Schauder basis
we offer another entropy, called the Auerbach entropy. Finally, we pose some
open problems.


title:
A Spatial Simulation Approach to Account for Protein Structure When
  Identifying Non-Random Somatic Mutations

abstract:
  Background: Current research suggests that a small set of "driver" mutations
are responsible for tumorigenesis while a larger body of "passenger" mutations
occurs in the tumor but does not progress the disease. Due to recent
pharmacological successes in treating cancers caused by driver mutations, a
variety of of methodologies that attempt to identify such mutations have been
developed. Based on the hypothesis that driver mutations tend to cluster in key
regions of the protein, the development of cluster identification algorithms
has become critical.
  Results: We have developed a novel methodology, SpacePAC (Spatial Protein
Amino acid Clustering), that identifies mutational clustering by considering
the protein tertiary structure directly in 3D space. By combining the
mutational data in the Catalogue of Somatic Mutations in Cancer (COSMIC) and
the spatial information in the Protein Data Bank (PDB), SpacePAC is able to
identify novel mutation clusters in many proteins such as FGFR3 and CHRM2. In
addition, SpacePAC is better able to localize the most significant mutational
hotspots as demonstrated in the cases of BRAF and ALK. The R package is
available on Bioconductor at:
http://www.bioconductor.org/packages/release/bioc/html/SpacePAC.html
  Conclusion: SpacePAC adds a valuable tool to the identification of mutational
clusters while considering protein tertiary structure


title: Polytropic inspired inflation

abstract:
  We study the chaotic inflation in the context of a gravity theory where the
Friedman equation is modified, inspired by the polytropic gas equation of
state. It is seen that in the $n=1$ case for the polytropic index the inflaton
field at the end of inflation $\phi_e$, depends on the Planck mass, while for
$n\neq1$ it generally depends on the polytropic constant and mass of the
inflaton field.


title:
Fundamental groups of manifolds with positive sectional curvature and
  torus symmetry

abstract:
  In 1965, S.-S. Chern posed a question concerning the extent to which
fundamental groups of manifolds admitting positive sectional curvature look
like spherical space form groups. The original question was answered in the
negative by Shankar in 1998, but there are a number of positive results in the
presence of symmetry. These classifications fall into categories according to
the strength of their conclusions. We give an overview of these results in the
case of torus symmetry and prove new results in each of these categories.


title: Lorentzian CR structures

abstract:
  The mathematics of a 4-dimensional renormalizable generally covariant
lagrangian model (with first order derivatives) is reviewed. The lorentzian CR
manifolds are totally real submanifolds of 4(complex)-dimensional complex
manifolds determined by four special conditions. The defining tetrad permits
the definition of a class of lorentzian metrics which admit two geodetic and
shear free congruences. These metrics permit the classification of the
structures using the Weyl tensor and the Flaherty pseudo-complex structure. The
Cartan procedure permits the definition of three relative invariants. Viewed as
a pair of two hypersurface-type 3-dimensional CR structures, the lorentzian CR
structures may be osculated on the basis of SU(1,2) group. An osculation on the
basis of SU(2,2) group reveals the Poincare group which may be identified with
the observed group in nature. Examples of static axially symmetric lorentzian
CR structures are computed. For every lorentzian CR manifold, a class of
Kaehler metrics of the ambient complex manifold is found, which induce the
class of compatible lorentzian metrics on the submanifold. Then the lorentzian
CR manifold becomes a lagrangian submanifold in the corresponding ambient
(Kaehler) symplectic manifold. The lorentzian CR manifolds may be considered as
dynamical processes in the context of the Einstein-Infeld-Hofman derivation of
the equations of motion.


title:
Landau damping effects and evolutions of energy spread in small
  isochronous ring

abstract:
  This paper presents the Landau damping effects on the microwave instability
of a coasting long bunch in an isochronous ring due to finite energy spread and
emittance. Our two-dimensional (2D) dispersion relation gives more accurate
predictions of the microwave instability growth rates of short-wavelength
perturbations than the conventional 1D formula. The long-term evolution of
energy spread is also studied by measurements and simulations.


title: Painlev\'e analysis of the Bryant Soliton

abstract:
  We carry out a Painlev\'e analysis of the systems of differential equations
corresponding to the steady and the expanding, rotationally symmetric, gradient
Ricci solitons on $\mathbb{R}^n$. For the steady case, dimensions of the form
$n=k^2+1$ are singled out, with dimensions 2, 5, and 10 being particularly
distinguished. Only dimension 2 is singled out for the expanding soliton.


title: On groups with locally compact asymptotic cones

abstract:
  We show how a recent result of Hrushovsky implies that if an asymptotic cone
of a finitely generated group is locally compact, then the group is virtually
nilpotent.


title:
High Order Lagrangian ADER-WENO Schemes on Unstructured Meshes -
  Application of Several Node Solvers to Hydrodynamics and Magnetohydrodynamics

abstract:
  In this paper we present a class of high order accurate cell-centered
Arbitrary-Eulerian-Lagrangian (ALE) one-step ADER-WENO finite volume schemes
for the solution of nonlinear hyperbolic conservation laws on two-dimensional
unstructured triangular meshes. High order of accuracy in space is achieved by
a WENO reconstruction algorithm, while a local space-time Galerkin predictor
allows the schemes to be high order accurate also in time by using an
element-local weak formulation of the governing PDE on moving meshes. The mesh
motion can be computed by choosing among three different node solvers, which
are for the first time compared with each other in this article: the node
velocity may be obtained i) either as an arithmetic average among the states
surrounding the node, or, ii) as a solution of multiple one-dimensional
half-Riemann problems around a vertex, or, iii) by solving approximately a
multidimensional Riemann problem around each vertex of the mesh using the
genuinely multidimensional HLL Riemann. Once the vertex velocity and thus the
new node location has been determined by the node solver, the local mesh motion
is then constructed by straight edges connecting the vertex positions at the
old time level with the new ones at the next time level. If necessary, a
rezoning step can be introduced here to overcome mesh tangling or highly
deformed elements. We apply the high order algorithm presented in this paper to
the Euler equations of compressible gas dynamics as well as to the ideal
classical and relativistic MHD equations. We show numerical convergence results
up to fifth order of accuracy in space and time together with some classical
numerical test problems for each hyperbolic system under consideration.


title: A Remark on Wick Ordering of Random Variables

abstract:
  This paper is a small note on the notation $\,:\! q(X)\!:\,$, for the Wick
ordering of polynomials $q$ of random variables $X = (X_1,\dotsc,X_n)$, as
introduced by Segal in [6]. We argue that expressing $q(X)$ as another
polynomial $p$ of a different set of random variables $Y = (Y_1,\dotsc,Y_m)$,
does not give rise to a different Wick ordered random variable $\, : \! p(Y) \!
: \,$, provided the new random variables $Y_j$ are linear combinations of the
$X_i$'s.


title:
Pair creation by collision of intense laser pulse with high-frequency
  photon beam

abstract:
  We consider pair creation by collision of a couple of counterpropagating
electromagnetic pulses with arbitrary frequency ratio, mostly in the context of
setup with collision of optical and coherent hard X- (or gamma-) ray pulses.
This problem is non-perturbative and in general does not admit exact analytical
solutions. We discuss several known approaches according to the ratio of the
parameters. Certain regions of the parameter space are not covered by the
existing approximations or models. We present a new simplified exactly solvable
model with one of the pulses being a delta-pulse. This model partially fills
the yet unexplored gap in the space of parameters. The shape of the momentum
distribution of the created particles in such a model is discussed. Even though
the model may not have immediate implications for the forthcoming experiments,
it can still provide some hints for better understanding of the fully
non-perturbative regime and vacuum instability in QED interactions of extremely
strong and short laser pulses.


title:
Sur la cohomologie des compactifications de vari\'et\'es de
  Deligne-Lusztig

abstract:
  In this article, we study the \'etale cohomology of the compactification of
Deligne-Lusztig varieties associated to a Coxeter element. We prove a result
for the integral coefficients in the case of general linear group $GL_d$, and
we conjecture that the similar result holds for general reductive groups.


title: Limit Theorems for Empirical Density of Greatest Common Divisors

abstract:
  The law of large numbers for the empirical density for the pairs of uniformly
distributed integers with a given greatest common divisor is a classic result
in number theory. In this paper, we study the large deviations of the empirical
density. We will also obtain a rate of convergence to the normal distribution
for the central limit theorem. Some generalizations are provided.


title: Self-Motion Mechanism Of Chained Spherical Grains Cells

abstract:
  Cells are modeled with spherical grains connected each other. Each cell can
shrink and swell by transporting its fluid content to other connected neighbor
while still maintaining its density at constant value. As a spherical part of a
cell swells it gains more pressure from its surrounding, while shrink state
gains less pressure. Pressure difference between these two or more parts of
cell will create motion force for the cell. For simplicity, cell is considered
to have same density as its environment fluid and connections between parts of
cell are virtually accommodated by a spring force. This model is also limited
to 2-d case. Influence of parameters to cell motion will be presented. One
grain cell shows no motion, while two and more grains cell can perform a
motion.


title:
Input Design for Model Discrimination and Fault Detection via Convex
  Relaxation

abstract:
  This paper addresses the design of input signals for the purpose of
discriminating among a finite set of models dynamic systems within a given
finite time interval. A motivating application is fault detection and
isolation. We propose several specific optimization problems, with objectives
or constraints based on signal power, signal amplitude, and probability of
successful model discrimination. Since these optimization problems are
nonconvex, we suggest a suboptimal solution via a random search algorithm
guided by the semidefinite relaxation (SDR) and analyze the accuracy of the
suboptimal solution. We conclude with a simple example taken from a benchmark
problem on fault detection for wind turbines.


title: Modularity and integral points on moduli schemes

abstract:
  The purpose of this paper is to give some new Diophantine applications of
modularity results. We use the Shimura-Taniyama conjecture to prove effective
finiteness results for integral points on moduli schemes of elliptic curves.
For several fundamental Diophantine problems (e.g. $S$-unit and Mordell
equations), this gives an effective method which does not rely on Diophantine
approximation or transcendence techniques. We also combine Faltings' method
with Serre's modularity conjecture, isogeny estimates and results from Arakelov
theory, to establish the effective Shafarevich conjecture for abelian varieties
of (product) GL$_2$-type. In particular, we open the way for the effective
study of integral points on certain higher dimensional moduli schemes.


title:
Properties of the ground $^3$F$_2$ state and the excited $^3$P$_0$ state
  of atomic thorium in cold collisions with $^3$He

abstract:
  We measure inelastic collisional cross sections for the ground $^3$F$_2$
state and the excited $^3$P$_0$ state of atomic thorium in cold collisions with
$^3$He. We determine for Th ($^3$F$_2$) at 800 mK the ratio $\gamma \approx
500$ of the momentum-transfer to Zeeman relaxation cross sections for
collisions with $^3$He. For Th ($^3$P$_0$), we study electronic inelastic
processes and find no quenching even after $10^6$ collisions. We also determine
the radiative lifetime of Th ($^3$P$_0$) to be $\tau > 130$ ms. This great
stability of the metastable state opens up the possibility for further study,
including trapping.


title:
A Complete Method of Comparative Statics for Optimization Problems
  (Unabbreviated Version)

abstract:
  A new method of deriving comparative statics information using generalized
compensated derivatives is presented which yields constraint-free
semidefiniteness results for any differentiable, constrained optimization
problem. More generally, it applies to any differentiable system governed by an
extremum principle, be it a physical system subject to the minimum action
principle, the equilibrium point of a game theoretical problem expressible as
an extremum, or a problem of decision theory with incomplete information
treated by the maximum entropy principle. The method of generalized compensated
derivatives is natural and powerful, and its underlying structure has a simple
and intuitively appealing geometric interpretation. Several extensions of the
main theorem such as envelope relations, symmetry properties and invariance
conditions, transformations of decision variables and parameters, degrees of
arbitrariness in the choice of comparative statics results, and rank relations
and inequalities are developed. The relationship of the new method to existing
formulations is established, thereby providing a unification of the main
differential comparative statics methods currently in use. A second theorem is
also established which yields exhaustive, constraint-free comparative statics
results for a general, constrained optimization problem. This theorem subsumes
all other comparative statics formulations. The method is illustrated with a
variety of models, some well known, such as profit and utility maximization,
where several novel extensions and results are derived, and some new, such as
the principal-agent problem, the efficient portfolio problem, a model of a
consumer with market power, and a cost-constrained profit maximization model.


title: Korovkin-type properties for completely positive maps

abstract:
  We prove a noncommutative variant of Saskin's classical theorem -- on the
connection between Choquet boundaries for function spaces and Korovkin sets --
for operator systems generating separable Type I C*-algebras. The main result
implies an affirmative answer to a weaker version of Arveson's hyperrigidity
conjecture for such C*-algebras. It also yields information about the more
general version of Arveson's conjecture.


title:
Search for a dijet resonance in events with jets and missing transverse
  energy in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV

abstract:
  We report on a search for a dijet resonance in events with only two or three
jets and large imbalance in the total event transverse momentum. This search is
sensitive to the possible production of a new particle in association with a
$W$ or $Z$ boson, where the boson decays leptonically with one or more
neutrinos in the final state. We use the full data set collected by the CDF II
detector at the Tevatron collider at a proton-antiproton center-of-mass energy
of 1.96 TeV. These data correspond to an integrated luminosity of 9.1
fb$^{-1}$. We study the invariant mass distribution of the two jets with
highest transverse energy. We find good agreement between data and standard
model background expectations and measure the combined cross section for WW,
WZ, and ZZ production to be $13.8^{+3.0}_{-2.7}$ pb. No significant anomalies
are observed in the mass spectrum and 95% credibility level upper limits are
set on the production rates of a potential new particle in association with a
$W$ or $Z$ boson.


title: Parallel Weighings

abstract:
  I introduce, solve and generalize a new coin puzzle that involves parallel
weighings.


title: Degrees of freedom for combining regression with factor analysis

abstract:
  In the AGEMAP genomics study, researchers were interested in detecting genes
related to age in a variety of tissue types. After not finding many age-related
genes in some of the analyzed tissue types, the study was criticized for having
low power. It is possible that the low power is due to the presence of
important unmeasured variables, and indeed we find that a latent factor model
appears to explain substantial variability not captured by measured covariates.
We propose including the estimated latent factors in a multiple regression
model. The key difficulty in doing so is assigning appropriate degrees of
freedom to the estimated factors to obtain unbiased error variance estimators
and enable valid hypothesis testing. When the number of responses is large
relative to the sample size, treating the estimated factors like observed
covariates leads to a downward bias in the variance estimates. Many ad-hoc
solutions to this problem have been proposed in the literature without the
backup of a careful theoretical analysis. Using recent results from random
matrix theory, we derive a simple, easy to use expression for degrees of
freedom. Our estimate gives a principled alternative to ad-hoc approaches in
common use. Extensive simulation results show excellent agreement between the
proposed estimator and its theoretical value. Applying our methodology to the
AGEMAP genomics study, we found an order of magnitude increase in the number of
significant genes. Although we focus on the AGEMAP study, the methods developed
in this paper are widely applicable to other multivariate models, and thus are
of independent interest.


title: On the Mar\v{c}enko-Pastur law for linear time series

abstract:
  This paper is concerned with extensions of the classical Mar\v{c}enko-Pastur
law to time series. Specifically, $p$-dimensional linear processes are
considered which are built from innovation vectors with independent,
identically distributed (real- or complex-valued) entries possessing zero mean,
unit variance and finite fourth moments. The coefficient matrices of the linear
process are assumed to be simultaneously diagonalizable. In this setting, the
limiting behavior of the empirical spectral distribution of both sample
covariance and symmetrized sample autocovariance matrices is determined in the
high-dimensional setting $p/n\to c\in (0,\infty)$ for which dimension $p$ and
sample size $n$ diverge to infinity at the same rate. The results extend
existing contributions available in the literature for the covariance case and
are one of the first of their kind for the autocovariance case.


title: Polynomials for symmetric orbit closures in the flag variety

abstract:
  In [Wyser-Yong '13] we introduced polynomial representatives of cohomology
classes of orbit closures in the flag variety, for the symmetric pair
$(GL_{p+q}, GL_p \times GL_q)$. We present analogous results for the remaining
symmetric pairs of the form $(GL_n,K)$, i.e., $(GL_n,O_n)$ and
$(GL_{2n},Sp_{2n})$. We establish the well-definedness of certain
representatives from [Wyser '13]. It is also shown that the representatives
have the combinatorial properties of nonnegativity and stability. Moreover, we
give some extensions to equivariant $K$-theory.


title: Which stresses affect the glide of screw dislocations in bcc metals?

abstract:
  By direct application of stress in molecular statics calculations we identify
the stress components that affect the glide of 1/2<111> screw dislocations in
bcc tungsten. These results prove that the hydrostatic stress and the normal
stress parallel to the dislocation line do not play any role in the dislocation
glide. Therefore, the Peierls stress of the dislocation cannot depend directly
on the remaining two normal stresses that are perpendicular to the dislocation,
as proposed by Koester A, Ma A, Hartmaier A. Acta Mater 2012;60:3894 but,
instead, on their combination that causes an equibiaxial tension-compression
(and thus shear) in the plane perpendicular to the dislocation line. The
Peierls stress of 1/2<111> screw dislocations then depends only on the
orientation of the plane in which the shear stress parallel to the Burgers
vector is applied and on the magnitude and orientation of the shear stress
perpendicular to the slip direction.


title: Symmetry Groups of $A_n$ Hypergeometric Series

abstract:
  Structures of symmetries of transformations for Holman-Biedenharn-Louck $A_n$
hypergeometric series: $A_n$ terminating balanced ${}_4 F_3$ series and $A_n$
elliptic ${}_{10} E_9$ series are discussed. Namely the description of the
invariance groups and the classification all of possible transformations for
each types of $A_n$ hypergeometric series are given. Among them, a "periodic"
affine Coxeter group which seems to be new in the literature arises as an
invariance group for a class of $A_n$ ${}_4 F_3$ series.


title:
Linear and synchrosqueezed time-frequency representations revisited.
  Part II: Resolution, reconstruction and concentration

abstract:
  Having reviewed the aspects of the linear and synchrosqueezed time-frequency
representations (TFRs) needed for their understanding and correct use in Part I
of this review, we now consider three more subtle issues that are nonetheless
of crucial importance for effective application of these methods. (i) What
effect do the window/wavelet parameters have on the resultant TFR, and how can
they most appropriately be chosen? (ii) What are the errors inherent in the two
reconstruction methods (direct and ridge) and which of them is the better?
(iii) What are the advantages and drawbacks associated with synchrosqueezing?
To answer these questions, we perform a detailed numerical and theoretical
study of the TFRs under consideration. We consider the relevant estimates in
the presence of the complications that arise in practical applications
including interference between components, amplitude modulation, frequency
modulation, and noise. Taken together, the results provide an in-depth
understanding of the issues in question.


title: The coordination dynamics of social neuromarkers

abstract:
  Social behavior is a complex integrative function that entails many aspects
of the brain's sensory, cognitive, emotional and motor capacities. Neural
processes are seldom simultaneous but occur according to precise temporal and
coordinative choreographies within and between brains. Methods with good
temporal resolution such as EEG can help to identify so-called "neuromarkers"
of social function (Tognoli, et al., 2007) and aid in disentangling the
dynamical architecture of social brains. We have studied neuromarkers and their
dynamics during synchronic interactions in which pairs of subjects coordinate
behavior spontaneously and intentionally (social coordination) and during
diachronic transactions that required subjects to perceive or behave in turn
(action observation and delayed imitation). We examined commonalities and
differences in the neuromarkers that are recruited for both kinds of tasks. We
found that the neuromarker landscape was task-specific: synchronic paradigms of
social coordination revealed medial mu, alpha and the phi complex as
contributing neuromarkers. Diachronic tasks recruited alpha as well, in
addition to lateral mu rhythms and the newly discovered nu and kappa rhythms
whose functional significance is still unclear. Social coordination,
observation, and delayed imitation share commonality of context: in our
experiments, subjects exchanged information through visual perception and moved
in similar ways. Nonetheless, there was little overlap between the neuromarkers
recruited for synchronic and diachronic tasks, a result that hints strongly of
task-specific neural mechanisms for social behaviors. The only neuromarker that
transcended both synchronic and diachronic social behaviors was the ubiquitous
alpha rhythm, which appears to be a key signature of visually-mediated social
behaviors. The present paper is both an entry point and a challenge...


title:
On the extraction of instantaneous frequencies from ridges in
  time-frequency representations of signals

abstract:
  The extraction of oscillatory components and their properties from different
time-frequency representations, such as windowed Fourier transform and wavelet
transform, is an important topic in signal processing. The first step in this
procedure is to find an appropriate ridge curve: a sequence of amplitude peak
positions (ridge points), corresponding to the component of interest. This is
not a trivial issue, and the optimal method for extraction is still not settled
or agreed. We discuss and develop procedures that can be used for this task and
compare their performance on both simulated and real data. In particular, we
propose a method which, in contrast to many other approaches, is highly
adaptive so that it does not need any parameter adjustment for the signal to be
analysed. Being based on dynamic path optimization and fixed point iteration,
the method is very fast, and its superior accuracy is also demonstrated. In
addition, we investigate the advantages and drawbacks that synchrosqueezing
offers in relation to curve extraction. The codes used in this work are freely
available for download.


title: Enlarging the scope: grasping brain complexity

abstract:
  To further advance our understanding of the brain, new concepts and theories
are needed. In particular, the ability of the brain to create information flows
must be reconciled with its propensity for synchronization and mass action. The
framework of Coordination Dynamics and the theory of metastability are
presented as a starting point to study the interplay of integrative and
segregative tendencies that are expressed in space and time during the normal
course of brain function. Some recent shifts in perspective are emphasized,
that may ultimately lead to a better understanding of brain complexity.


title: Robust Hypothesis Testing via Lq-Likelihood

abstract:
  This article introduces a robust hypothesis testing procedure: the
Lq-likelihood-ratio-type test (LqRT). By deriving the asymptotic distribution
of this test statistic, the authors demonstrate its robustness both
analytically and numerically, and they investigate the properties of both its
influence function and its breakdown point. A proposed method to select the
tuning parameter q offers a good efficiency/robustness trade-off, compared with
the traditional likelihood ratio test (LRT) and other robust tests. A
simulation and real data analysis provides further evidence of the advantages
of the proposed LqRT method. In particular, for the special case of testing the
location parameter in the presence of gross error contamination, the LqRT
dominates the Wilcoxon-Mann-Whitney test and the sign test at various levels of
contamination.


title:
Vibrational quenching of the electronic ground state in ThO in cold
  collisions with $^3$He

abstract:
  We measure the ratio $\gamma$ of the momentum-transfer to the vibrational
quenching cross section for the X ($^1\Sigma^+$), $\nu=1$, $\mathrm{J=0}$ state
of molecular thorium monoxide (ThO) in collisions with atomic $^3$He between
800 mK and 2.4 K. We observe indirect evidence for ThO--He van der Waals'
complex formation, which has been predicted by theory. We determine the 3-body
recombination rate constant $\Gamma_3$ at 2.4 K, and establish that the binding
energy E$_b >$ 4 K.


title: The stochastic field of aggregate utilities and its saddle conjugate

abstract:
  We describe the sample paths of the stochastic field $F = F_t(v,x,q)$ of
aggregate utilities parameterized by Pareto weights $v$ and total cash amounts
$x$ and stocks' quantities $q$ in an economy. We also describe the sample paths
of the stochastic field $G = G_t(u,y,q)$, which is conjugate to $F$ with
respect to the saddle arguments $(v,x)$, and obtain various conjugacy relations
between these stochastic fields. The results of this paper play a key role in
our study of a continuous-time price impact model.


title:
Coupling of two conformal field theories and Nakajima-Yoshioka blow-up
  equations

abstract:
  We study the conformal vertex algebras which naturally arise in relation to
the Nakajima-Yoshioka blow-up equations.


title: Massive MIMO Systems: Signal Processing Challenges and Research Trends

abstract:
  This article presents a tutorial on multiuser multiple-antenna wireless
systems with a very large number of antennas, known as massive multi-input
multi-output (MIMO) systems. Signal processing challenges and future trends in
the area of massive MIMO systems are presented and key application scenarios
are detailed. A linear algebra approach is considered for the description of
the system and data models of massive MIMO architectures. The operational
requirements of massive MIMO systems are discussed along with their operation
in time-division duplexing mode, resource allocation and calibration
requirements. In particular, transmit and receiver processing algorithms are
examined in light of the specific needs of massive MIMO systems. Simulation
results illustrate the performance of transmit and receive processing
algorithms under scenarios of interest. Key problems are discussed and future
trends in the area of massive MIMO systems are pointed out.


title: Fragility of the fractional quantum spin Hall effect in quantum gases

abstract:
  We consider the effect of contact interaction in a prototypical quantum spin
Hall system of pseudo-spin-1/2 particles. A strong effective magnetic field
with opposite directions for the two spin states restricts two-dimensional
particle motion to the lowest Landau level. While interaction between same-spin
particles leads to incompressible correlated states at fractional filling
factors as known from the fractional quantum Hall effect, these states are
destabilized by interactions between opposite spin particles. Exact results for
two particles with opposite spin reveal a quasi-continuous spectrum of extended
states with a large density of states at low energy. This has implications for
the prospects of realizing the fractional quantum spin Hall effect in
electronic or ultra-cold atom systems. Numerical diagonalization is used to
extend the two-particle results to many bosonic particles and trapped systems.
The interplay between an external trapping potential and spin-dependent
interactions is shown to open up new possibilities for engineering exotic
correlated many-particle states with ultra-cold atoms.


title:
Pick-off annihilation of positronium in matter using full correlation
  single particle potentials: solid He

abstract:
  We investigate the modeling of positronium (Ps) states and their pick-off
annihilation trapped at open volumes pockets in condensed molecular matter. Our
starting point is the interacting many-body system of Ps and a He atom because
it is the smallest entity that can mimic the energy gap between the highest
occupied and lowest unoccupied molecular orbitals of molecules and yet the the
many-body structure of the HePs system can be calculated accurately enough. The
exact-diagonalization solution of the HePs system enables us to construct a
pair-wise full-correlation single-particle potential for the Ps-He interaction
and the total potential in solids is obtained as a superposition of the
pair-wise potentials. We study in detail Ps states and their pick-off
annihilation rates in voids inside solid He and analyse experimental results
for Ps-induced voids in liquid He obtaining the radii of the voids. More
importantly, we generalize our conclusions by testing the validity of the
Tao-Eldrup model, widely used to analyse ortho-Ps annihilation measurements for
voids in molecular matter, against our theoretical results for the solid He.
Moreover, we discuss the influence of the partial charges of polar molecules
and the strength of the van der Waals interaction on the pick-off annihilation
rate.


title:
Continuously tunable electronic structure of transition metal
  dichalcogenides superlattices

abstract:
  Two dimensional transition metal dichalcogenides (TMDC) have very interesting
properties for optoelectronic devices. In this work we theoretically
investigate and predict that superlattices comprised of MoS$_{2}$ and WSe$_{2}$
multilayers possess continuously tunable electronic structure having direct
band gap. The tunability is controlled by the thickness ratio of MoS$_{2}$
versus WSe$_{2}$ of the superlattice. When this ratio goes from 1:2 to 5:1, the
dominant K-K direct band gap is continuously tuned from 0.14 eV to 0.5 eV. The
gap stays direct against -0.6% to 2% in-layer strain and up to -4.3%
normal-layer compressive strain. The valance and conduction bands are spatially
separated. These robust properties suggest that MoS$_{2}$ and WSe$_{2}$
multilayer superlattice should be an exciting emerging material for infrared
optoelectronics.


title:
Single-photon router: Coherent Control of multi-channel scattering for
  single-photons with quantum interferences

abstract:
  We propose a single-photon router using a single atom with an inversion
center coupled to quantum multichannels made of coupled-resonator waveguides.
We show that the spontaneous emission of the atom can direct single photons
from one quantum channel into another. The on-demand classical field perfectly
switches-off the single-photon routing due to the quantum interference in the
atomic amplitudes of optical transitions. Total reflections in the incident
channel are due to the photonic bound state in the continuum. Two virtual
channels, named as scatter-free and controllable channels, are found, which are
coherent superpositions of quantum channels. Any incident photon in the
scatter-free channel is totally transmitted. The propagating states of the
controllable channel are orthogonal to those of the scatter-free channel.
Single photons in the controllable channel can be perfectly reflected or
transmitted by the atom.


title:
High-resolution gamma-ray spectroscopy with a microwave-multiplexed
  transition-edge sensor array

abstract:
  We demonstrate very high resolution photon spectroscopy with a
microwave-multiplexed two-pixel transition-edge sensor (TES) array. We measured
a $^{153}$Gd photon source and achieved an energy resolution of 63 eV
full-width-at-half-maximum at 97 keV and an equivalent readout system noise of
86 pA/$\sqrt{\text{Hz}}$ at the TES. The readout circuit consists of
superconducting microwave resonators coupled to radio-frequency
superconducting-quantum-interference-devices (SQUID) and transduces changes in
input current to changes in phase of a microwave signal. We use flux-ramp
modulation to linearize the response and evade low-frequency noise. This
demonstration establishes one path for the readout of cryogenic X-ray and
gamma-ray sensor arrays with more than $10^3$ elements and spectral resolving
powers $R=\lambda/\Delta\lambda > 10^3$.


title: The Number of Distinct Subsequences of a Random Binary String

abstract:
  We determine the average number of distinct subsequences in a random binary
string, and derive an estimate for the average number of distinct subsequences
of a particular length.


title: Some transcendence results from a harmless irrationality theorem

abstract:
  The arithmetic nature of values of some functions of a single variable,
particularly, $\sin{z}$, $\cos{z}$, $\sinh{z}$, $\cosh{z}$, $e^z$, and
$\ln{z}$, is a relevant topic in number theory. For instance, all those
functions return transcendental values for all non-zero algebraic values of $z$
($z \ne 1$ in the case of $\ln{z}$). On the other hand, not even an
irrationality proof is known for some numbers like $\,e^e$, $\,\pi^e$,
$\,\pi^\pi$, $\,\ln{\pi}$, $\,\pi + e\,$ and $\,\pi \, e$, though it is
well-known that at least one of the last two numbers is irrational. In this
note, I first derive a more general form of this last result, showing that at
least one of the sum and product of any two transcendental numbers is
transcendental. I then use this to show that, given any complex number $\,t \ne
0, 1/e$, at least two of the numbers $\,\ln{t}$, $\,t + e\,$ and $\,t \, e\,$
are transcendental. I also show that $\,\cosh{z}$, $\sinh{z}\,$ and
$\,\tanh{z}\,$ return transcendental values for all $\,z = r \, \ln{t}$, $\,r
\in \mathbb{Q}$, $r \ne 0$. Finally, I use a recent algebraic independence
result by Nesterenko to show that, for all integer $\,n > 0$, $\,\ln{\pi}\,$
and $\,\sqrt{n} \, \pi\,$ are linearly independent over $\mathbb{Q}$.