title: Decay rates for approximation numbers of composition operators

abstract:
  A general method for estimating the approximation numbers of composition
operators on $\Ht$, using finite-dimensional model subspaces, is studied and
applied in the case when the symbol of the operator maps the unit disc to a
domain whose boundary meets the unit circle at just one point. The exact rate
of decay of the approximation numbers is identified when this map is
sufficiently smooth at the point of tangency; it follows that a composition
operator with any prescribed slow decay of its approximation numbers can be
explicitly constructed. Similarly, an asymptotic expression for the
approximation numbers is found when the mapping has a sharp cusp at the
distinguished boundary point. Precise asymptotic estimates in the intermediate
cases, including that of maps with a corner at the distinguished boundary
point, are also established.


title:
Approximation numbers of composition operators on the $H^2$ space of
  Dirichlet series

abstract:
  By a theorem of Gordon and Hedenmalm, $\varphi$ generates a bounded
composition operator on the Hilbert space $\mathscr{H}^2$ of Dirichlet series
$\sum_n b_n n^{-s}$ with square-summable coefficients $b_n$ if and only if
$\varphi(s)=c_0 s+\psi(s)$, where $c_0$ is a nonnegative integer and $\psi$ a
Dirichlet series with the following mapping properties: $\psi$ maps the right
half-plane into the half-plane $\operatorname{Re} s >1/2$ if $c_0=0$ and is
either identically zero or maps the right half-plane into itself if $c_0$ is
positive. It is shown that the $n$th approximation numbers of bounded
composition operators on $\mathscr{H}^2$ are bounded below by a constant times
$r^n$ for some $0<r<1$ when $c_0=0$ and bounded below by a constant times
$n^{-A}$ for some $A>0$ when $c_0$ is positive. Both results are best possible.
The case when $c_0=0$, $\psi$ is bounded and smooth up to the boundary of the
right half-plane, and $\sup \operatorname{Re} \psi=1/2$, is discussed in depth;
it includes examples of non-compact operators as well as operators belonging to
all Schatten classes $S_p$. For $\varphi(s)=c_1+\sum_{j=1}^d c_{q_j} q_j^{-s}$
with $q_j$ independent integers, it is shown that the $n$th approximation
number behaves as $n^{-(d-1)/2}$, possibly up to a factor $(\log n)^{(d-1)/2}$.
Estimates rely mainly on a general Hilbert space method involving finite linear
combinations of reproducing kernels. A key role is played by a recently
developed interpolation method for $\mathscr{H}^2$ using estimates of solutions
of the $\bar{\partial}$ equation. Finally, by a transference principle from
$H^2$ of the unit disc, explicit examples of compact composition operators with
approximation numbers decaying at essentially any sub-exponential rate can be
displayed.


title: Target Estimation in Colocated MIMO Radar via Matrix Completion

abstract:
  We consider a colocated MIMO radar scenario, in which the receive antennas
forward their measurements to a fusion center. Based on the received data, the
fusion center formulates a matrix which is then used for target parameter
estimation. When the receive antennas sample the target returns at Nyquist
rate, and assuming that there are more receive antennas than targets, the data
matrix at the fusion center is low-rank. When each receive antenna sends to the
fusion center only a small number of samples, along with the sample index, the
receive data matrix has missing elements, corresponding to the samples that
were not forwarded. Under certain conditions, matrix completion techniques can
be applied to recover the full receive data matrix, which can then be used in
conjunction with array processing techniques, e.g., MUSIC, to obtain target
information. Numerical results indicate that good target recovery can be
achieved with occupancy of the receive data matrix as low as 50%.


title: On $m$-Kropina Finsler Metrics of Scalar Flag Curvature

abstract:
  In this paper, we consider a special class of singular Finsler metrics:
$m$-Kropina metrics which are defined by a Riemannian metric and a $1$-form. We
show that an $m$-Kropina metric ($m\ne -1$) of scalar flag curvature must be
locally Minkowskian in dimension $n\ge 3$. We characterize by some PDEs a
Kropina metric ($m=-1$) which is respectively of scalar flag curvature and
locally projectively flat in dimension $n\ge 3$, and obtain some principles and
approaches of constructing non-trivial examples of Kropina metrics of scalar
flag curvature.


title:
On a Class of Two-Dimensional Singular Douglas and Projectively flat
  Finsler Metrics

abstract:
  Singular Finsler metrics, such as Kropina metrics and $m$-Kropina metrics,
have a lot of applications in the real world. In this paper, we study a class
of two-dimensional singular Finsler metrics defined by a Riemann metric
$\alpha$ and 1-form $\beta$, and we characterize those which are Douglasian or
locally projectively flat by some equations. It shows that the main class
induced is an $m$-Kropina metric plus a linear part on $\beta$. For this class,
the local structure of Douglasian or (in part) projectively flat case is
determined, and in particular we show that a Kropina metric is always
Douglasian and a Douglas $m$-Kropina metric with $m\ne -1$ is locally
Minkowskian. It indicates that the two-dimensional case is quite different from
the higher dimensional ones.


title:
Further Comment on 'Encoding many channels on the same frequency through
  radio vorticity: first experimental test'

abstract:
  We show that the reply by Tamburini et al (2012 New J. Phys. 14 118002) to
our previous comment (2012 New J. Phys. 14 118001) on the experiment reported
in (2012 New J. Phys. 14 033001) actually does not invalidate any of the issues
raised in our initial comment.


title: Protected gates for superconducting qubits

abstract:
  We analyze the accuracy of quantum phase gates acting on "0-$\pi$ qubits" in
superconducting circuits, where the gates are protected against thermal and
Hamiltonian noise by continuous-variable quantum error-correcting codes. The
gates are executed by turning on and off a tunable Josephson coupling between
an $LC$ oscillator and a qubit or pair of quits; assuming perfect qubits, we
show that the gate errors are exponentially small when the oscillator's
impedance $\sqrt{L/C}$ is large compared to $\hbar/4e^2 \approx 1\, k\Omega$.
The protected gates are not computationally universal by themselves, but a
scheme for universal fault-tolerant quantum computation can be constructed by
combining them with unprotected noisy operations. We validate our analytic
arguments with numerical simulations.


title: An analogue to the Witt identity

abstract:
  In this paper we solve combinatorial and algebraic problems associated with a
multivariate identity first considered by S. Sherman wich he called an analog
to the Witt identity. We extend previous results obtained for the univariante
case.


title:
On 2-dimensional nonaspherical cell-like Peano continua: A simplified
  approach

abstract:
  We construct a functor $AC(-,-)$ from the category of path connected spaces
$X$ with a base point $x$ to the category of simply connected spaces. The
following are the main results of the paper: (i) If $X$ is a Peano continuum
then $AC(X,x)$ is a cell-like Peano continuum; (ii) If $X$ is $n-$dimensional
then $AC(X, x)$ is $(n+1)-$dimensional; and (iii) For a path connected space
$X$, $\pi_1(X,x)$ is trivial if and only if $\pi_2(AC(X, x))$ is trivial. As a
corollary, $AC(S^1, x)$ is a 2-dimensional nonaspherical cell-like Peano
continuum.


title: Strain-induced topological insulator phase transition in HgSe

abstract:
  Using ab initio electronic structure calculations we investigate the change
of the band structure and the nu_0 topological invariant in HgSe
(non-centrosymmetric system) under two different type of uniaxial strain along
the [001] and [110] directions, respectively. Both compressive [001] and [110]
strain leads to the opening of a (crystal field) band gap (with a maximum value
of about 37 meV) in the vicinity of Gamma, and the concomitant formation of a
camel-back- (inverse camel-back-) shape valence (conduction) band along the
direction perpendicular to the strain with a minimum (maximum) at Gamma. We
find that the Z_2 invariant nu_0=1, which demonstrates conclusively that HgSe
is a strong topological insulator (TI). With further increase of the strain the
band gap decreases vanishing at a critical strain value (which depends on the
strain type) where HgSe undergoes a transition from a strong TI to a trivial
(normal) insulator. HgSe exhibits a similar behavior under a tensile [110]
uniaxial strain. On the other hand, HgSe remains a normal insulator by applying
a [001] tensile uniaxial strain. Complementary electronic structure
calculations of the non-polar (110) surface under compressive [110] tensile
strain show two Dirac cones at the Gamma point whose spin chiral states are
associated with the top and bottom slab surfaces.


title:
Manifestation of Strong Quadrupole Light-Molecule Interaction in the
  SEIRA Spectra of Some Symmetrical Molecules

abstract:
  It is demonstrated, that the forbidden lines, which were observed in the
SEIRA spectra of diprotonated BiPyH22+ and ethylene, adsorbed on Cu, as well as
on ethylene, adsorbed on mordenites can be explained on the base of the
Dipole-Quadrupole theory of SEIRA and is the consequence of the existence of
the strong quadrupole light-molecule interaction.


title:
Adaptive Set-Membership Reduced-Rank Least Squares Beamforming
  Algorithms

abstract:
  This paper presents a new adaptive algorithm for the linearly constrained
minimum variance (LCMV) beamformer design. We incorporate the set-membership
filtering (SMF) mechanism into the reduced-rank joint iterative optimization
(JIO) scheme to develop a constrained recursive least squares (RLS) based
algorithm called JIO-SM-RLS. The proposed algorithm inherits the positive
features of reduced-rank signal processing techniques to enhance the output
performance, and utilizes the data-selective updates (around 10-15%) of the SMF
methodology to save the computational cost significantly. An effective
time-varying bound is imposed on the array output as a constraint to circumvent
the risk of overbounding or underbounding, and to update the parameters for
beamforming. The updated parameters construct a set of solutions (a membership
set) that satisfy the constraints of the LCMV beamformer. Simulations are
performed to show the superior performance of the proposed algorithm in terms
of the convergence rate and the reduced computational complexity in comparison
with the existing methods.


title:
Low Delay MAC Scheduling for Frequency-agile Multi-radio Wireless
  Networks

abstract:
  Recent trends suggest that cognitive radio based wireless networks will be
frequency agile and the nodes will be equipped with multiple radios capable of
tuning across large swaths of spectrum. The MAC scheduling problem in such
networks refers to making intelligent decisions on which communication links to
activate at which time instant and over which frequency band. The challenge in
designing a low-complexity distributed MAC, that achieves low delay, is posed
by two additional dimensions of cognitive radio networks: interference graphs
and data rates that are frequency-band dependent, and explosion in number of
feasible schedules due to large number of available frequency-bands. In this
paper, we propose MAXIMALGAIN MAC, a distributed MAC scheduler for frequency
agile multi-band networks that simultaneously achieves the following: (i)
optimal network-delay scaling with respect to the number of communicating
pairs, (ii) low computational complexity of O(log2(maximum degree of the
interference graphs)) which is independent of the number of frequency bands,
number of radios per node, and overall size of the network, and (iii)
robustness, i.e., it can be adapted to a scenario where nodes are not
synchronized and control packets could be lost. Our proposed MAC also achieves
a throughput provably within a constant fraction (under isotropic propagation)
of the maximum throughput. Due to a recent impossibility result, optimal
delay-scaling could only be achieved with some amount of throughput loss [30].
Extensive simulations using OMNeT++ network simulator shows that, compared to a
multi-band extension of a state-of-art CSMA algorithm (namely, Q-CSMA), our
asynchronous algorithm achieves a 2.5x? reduction in delay while achieving at
least 85% of the maximum achievable throughput. Our MAC algorithms are derived
from a novel local search based technique.


title: Repair-Optimal MDS Array Codes over GF(2)

abstract:
  Maximum-distance separable (MDS) array codes with high rate and an optimal
repair property were introduced recently. These codes could be applied in
distributed storage systems, where they minimize the communication and disk
access required for the recovery of failed nodes. However, the encoding and
decoding algorithms of the proposed codes use arithmetic over finite fields of
order greater than 2, which could result in a complex implementation.
  In this work, we present a construction of 2-parity MDS array codes, that
allow for optimal repair of a failed information node using XOR operations
only. The reduction of the field order is achieved by allowing more parity bits
to be updated when a single information bit is being changed by the user.


title:
Adaptive Minimum BER Reduced-Rank Interference Suppression Algorithms
  Based on Joint and Iterative Optimization of Parameters

abstract:
  In this letter, we propose a novel adaptive reduced-rank strategy based on
joint iterative optimization (JIO) of filters according to the minimization of
the bit error rate (BER) cost function. The proposed optimization technique
adjusts the weights of a subspace projection matrix and a reduced-rank filter
jointly. We develop stochastic gradient (SG) algorithms for their adaptive
implementation and introduce a novel automatic rank selection method based on
the BER criterion. Simulation results for direct-sequence
code-division-multiple-access (DS-CDMA) systems show that the proposed adaptive
algorithms significantly outperform the existing schemes.


title:
Photon statistics in the dynamical Casimir effect modified by a harmonic
  oscillator detector

abstract:
  It was predicted some time ago that the cavity dynamical Casimir effect
(generation of photons from the initial vacuum state in a cavity with moving
walls) might be observed if a boundary vibrates at the double frequency of some
selected cavity mode. However, to register the created photons one has to
couple the cavity mode with some detector. Considering the harmonic oscillator
model of a detector, we analyze how different coupling regimes can affect the
statistics of the created quanta.


title:
A simple stochastic parameterization for reduced models of multiscale
  dynamics

abstract:
  Multiscale dynamics are frequently present in real-world processes, such as
the atmosphere-ocean and climate science. Because of time scale separation
between a small set of slowly evolving variables and much larger set of rapidly
changing variables, direct numerical simulations of such systems are difficult
to carry out due to many dynamical variables and the need for an extremely
small time discretization step to resolve fast dynamics. One of the common
remedies for that is to approximate a multiscale dynamical systems by a closed
approximate model for slow variables alone, which reduces the total effective
dimension of the phase space of dynamics, as well as allows for a longer time
discretization step. Recently we developed a new method for constructing a
deterministic reduced model of multiscale dynamics where coupling terms were
parameterized via the Fluctuation-Dissipation theorem. In this work we further
improve this previously developed method for deterministic reduced models of
multiscale dynamics by introducing a new method for parameterizing slow-fast
interactions through additive stochastic noise in a systematic fashion. For the
two-scale Lorenz 96 system with linear coupling, we demonstrate that the new
method is able to recover additional features of multiscale dynamics in a
stochastically forced reduced model, which the previously developed
deterministic method could not reproduce.


title:
The (Un)Reliability of NVD Vulnerable Versions Data: an Empirical
  Experiment on Google Chrome Vulnerabilities

abstract:
  NVD is one of the most popular databases used by researchers to conduct
empirical research on data sets of vulnerabilities. Our recent analysis on
Chrome vulnerability data reported by NVD has revealed an abnormally phenomenon
in the data where almost vulnerabilities were originated from the first
versions. This inspires our experiment to validate the reliability of the NVD
vulnerable version data. In this experiment, we verify for each version of
Chrome that NVD claims vulnerable is actually vulnerable. The experiment
revealed several errors in the vulnerability data of Chrome. Furthermore, we
have also analyzed how these errors might impact the conclusions of an
empirical study on foundational vulnerability. Our results show that different
conclusions could be obtained due to the data errors.


title: Invariants of moduli spaces of stable sheaves on ruled surfaces

abstract:
  We compute Betti numbers of the moduli spaces of arbitrary rank stable
sheaves on ruled surfaces. Our result generalizes the formula of Goettsche for
rank one sheaves and the formula of Yoshioka for rank two sheaves. It also
confirms the conjecture of Manschot for arbitrary rank sheaves on the
Hirzebruch surfaces.


title: The corona algebra of stablized Jiang-Su algebra

abstract:
  Let ${\cal Z}$ be the Jiang-Su algebra and ${\cal K}$ the C*-algebra of
compact operators on an infinite dimensional separable Hilbert space. We prove
that the corona algebra $M({\cal Z}\otimes {\cal K})/{\cal Z}\otimes {\cal K}$
has real rank zero. We actually prove a more general result.


title:
Post-buckling Solutions of Hyper-elastic Beam by Canonical Dual Finite
  Element Method

abstract:
  Post buckling problem of a large deformed beam is analyzed using canonical
dual finite element method (CD-FEM). The feature of this method is to choose
correctly the canonical dual stress so that the original non-convex potential
energy functional is reformulated in a mixed complementary energy form with
both displacement and stress fields, and a pure complementary energy is
explicitly formulated in finite dimensional space. Based on the canonical
duality theory and the associated triality theorem, a primal-dual algorithm is
proposed, which can be used to find all possible solutions of this nonconvex
post-buckling problem. Numerical results show that the global maximum of the
pure-complementary energy leads to a stable buckled configuration of the beam.
While the local extrema of the pure-complementary energy present unstable
deformation states, especially. We discovered that the unstable buckled state
is very sensitive to the number of total elements and the external loads.
Theoretical results are verified through numerical examples and some
interesting phenomena in post-bifurcation of this large deformed beam are
observed.


title:
On the dynamical stability of the proposed planetary system orbiting
  NSVS 14256825

abstract:
  We present a detailed dynamical analysis of the orbital stability of the two
circumbinary planets recently proposed to orbit the evolved eclipsing binary
star system NSVS 14256825. As is the case for other recently proposed
circumbinary planetary systems detected through the timing of mutual eclipses
between the central binary stars, the proposed planets do not stand up to
dynamical scrutiny. The proposed orbits for the two planets are extremely
unstable on timescales of less than a thousand years, regardless of the mutual
inclination between the planetary orbits.
  For the scenario where the planetary orbits are coplanar, a small region of
moderate stability was observed, featuring orbits that were somewhat protected
from destabilisation by the influence of mutual 2:1 mean-motion resonance
between the orbits of the planets. Even in this stable region, however, the
systems tested typically only survived on timescales of order 1 million years,
far shorter than the age of the system.
  Our results suggest that, if there are planets in the NSVS 14256825 system,
they must move on orbits dramatically different to those proposed in the
discovery work. More observations are clearly critically required in order to
constrain the nature of the suggested orbital bodies.


title: Multi-parameter Mechanisms with Implicit Payment Computation

abstract:
  In this paper we show that payment computation essentially does not present
any obstacle in designing truthful mechanisms, even for multi-parameter
domains, and even when we can only call the allocation rule once. We present a
general reduction that takes any allocation rule which satisfies "cyclic
monotonicity" (a known necessary and sufficient condition for truthfulness) and
converts it to a truthful mechanism using a single call to the allocation rule,
with arbitrarily small loss to the expected social welfare.
  A prominent example for a multi-parameter setting in which an allocation rule
can only be called once arises in sponsored search auctions. These are
multi-parameter domains when each advertiser has multiple possible ads he may
display, each with a different value per click. Moreover, the mechanism
typically does not have complete knowledge of the click-realization or the
click-through rates (CTRs); it can only call the allocation rule a single time
and observe the click information for ads that were presented. % are not known.
On the negative side, we show that an allocation that is truthful for any
realization essentially cannot depend on the bids, and hence cannot do better
than random selection for one agent. We then consider a relaxed requirement of
truthfulness, only in expectation over the CTRs. Even for that relaxed version,
making any progress is challenging as standard techniques for construction of
truthful mechanisms (as using VCG or an MIDR allocation rule) cannot be used in
this setting. We design an allocation rule with non-trivial performance and
directly prove it is cyclic-monotone, and thus it can be used to create a
truthful mechanism using our general reduction.


title:
Security analysis of the decoy method with the Bennett-Brassard 1984
  protocol for finite key lengths

abstract:
  This paper provides a formula for the sacrifice bit-length for privacy
amplification with the Bennett-Brassard 1984 protocol for finite key lengths
when we employ the decoy method. Using the formula, we can guarantee the
security parameter for realizable quantum key distribution system. The key
generation rates with finite key lengths are numerically evaluated. The
proposed method improves the existing key generation rate even in the
asymptotic setting.


title: Thermodynamics of the Coma Cluster Outskirts

abstract:
  We present results from a large mosaic of Suzaku observations of the Coma
Cluster, the nearest and X-ray brightest hot, dynamically active, non-cool core
system, focusing on the thermodynamic properties of the ICM on large scales.
For azimuths not aligned with an infalling subcluster towards the southwest,
our measured temperature and X-ray brightness profiles exhibit broadly
consistent radial trends, with the temperature decreasing from about 8.5 keV at
the cluster center to about 2 keV at a radius of 2 Mpc, which is the edge of
our detection limit. The SW merger significantly boosts the surface brightness,
allowing us to detect X-ray emission out to ~2.2 Mpc along this direction.
Apart from the southwestern infalling subcluster, the surface brightness
profiles show multiple edges around radii of 30-40 arcmin. The azimuthally
averaged temperature profile, as well as the deprojected density and pressure
profiles, all show a sharp drop consistent with an outward propagating shock
front located at 40 arcmin, corresponding to the outermost edge of the giant
radio halo observed at 352 MHz with the WSRT. The shock front may be powering
this radio emission. A clear entropy excess inside of r_500 reflects the
violent merging events linked with these morphological features. Beyond r_500,
the entropy profiles of the Coma Cluster along the relatively relaxed
directions are consistent with the power-law behavior expected from simple
models of gravitational large-scale structure formation. The pressure is also
in agreement at these radii with the expected values measured from SZ data from
the Planck satellite. However, due to the large uncertainties associated with
the Coma Cluster measurements, we cannot yet exclude an entropy flattening in
this system consistent with that seen in more relaxed cool core clusters.


title:
Canonical dual solutions to nonconvex radial basis neural network
  optimization problem

abstract:
  Radial Basis Functions Neural Networks (RBFNNs) are tools widely used in
regression problems. One of their principal drawbacks is that the formulation
corresponding to the training with the supervision of both the centers and the
weights is a highly non-convex optimization problem, which leads to some
fundamentally difficulties for traditional optimization theory and methods.
  This paper presents a generalized canonical duality theory for solving this
challenging problem. We demonstrate that by sequential canonical dual
transformations, the nonconvex optimization problem of the RBFNN can be
reformulated as a canonical dual problem (without duality gap). Both global
optimal solution and local extrema can be classified. Several applications to
one of the most used Radial Basis Functions, the Gaussian function, are
illustrated. Our results show that even for one-dimensional case, the global
minimizer of the nonconvex problem may not be the best solution to the RBFNNs,
and the canonical dual theory is a promising tool for solving general neural
networks training problems.


title: A constructive approach to stationary scattering theory

abstract:
  In this paper we give a new and constructive approach to stationary
scattering theory for pairs of self-adjoint operators $H_0$ and $H_1$ on a
Hilbert space $\mathcal H$ which satisfy the following conditions: (i) for any
open bounded subset $\Delta$ of $\mathbb R,$ the operators $F E_\Delta^{H_0}$
and $F E_\Delta^{H_1}$ are Hilbert-Schmidt and (ii) $V = H_1- H_0$ is bounded
and admits decomposition $V = F^*JF,$ where $F$ is a bounded operator with
trivial kernel from $\mathcal H$ to another Hilbert space $\mathcal K$ and $J$
is a bounded self-adjoint operator on $\mathcal K.$ An example of a pair of
operators which satisfy these conditions is the Schr\"odinger operator $H_0 =
-\Delta + V_0$ acting on $L^2(\mathbb R^\nu),$ where $V_0$ is a potential of
class $K_\nu$ (see B.\,Simon, {\it Schr\"odinger semigroups,} Bull. AMS 7,
1982, 447--526) and $H_1 = H_0 + V_1,$ where $V_1 \in L^\infty(\mathbb R^\nu)
\cap L^1(\mathbb R^\nu).$ Among results of this paper is a new proof of
existence and completeness of wave operators $W_\pm(H_1,H_0)$ and a new
constructive proof of stationary formula for the scattering matrix. This
approach to scattering theory is based on explicit diagonalization of a
self-adjoint operator $H$ on a sheaf of Hilbert spaces $\EuScript S(H,F)$
associated with the pair $(H,F)$ and with subsequent construction and study of
properties of wave matrices $w_\pm(\lambda; H_1,H_0)$ acting between fibers
$\mathfrak h_\lambda(H_0,F)$ and $\mathfrak h_\lambda(H_1,F)$ of sheaves
$\EuScript S(H_0,F)$ and $\EuScript S(H_1,F)$ respectively. The wave operators
$W_\pm(H_1,H_0)$ are then defined as direct integrals of wave matrices and are
proved to coincide with classical time-dependent definition of wave operators.


title: Properties of oscillation modes in subgiant stars observed by Kepler

abstract:
  Mixed modes seen in evolved stars carry information on their deeper layers
that can place stringent constraints on their physics and on their global
properties (mass, age, etc...). In this study, we present a method to identify
and measure all oscillatory mode characteristics (frequency, height, width).
Analyzing four subgiants stars, we present the first measure of the effect of
the degree of mixture on the l=1 mixed modes characteristics. We also show that
some stars have measurable l=2 mixed modes and discuss the interest of their
measure to constrain the deeper layers of stars.


title:
Temperature Dependence of the Magnetic Penetration Depth and Nodal Gap
  Structure of UPt$_3$ from Small Angle Neutron Scattering

abstract:
  Spanning a broad range of physical systems, complex symmetry breaking is
widely recognized as a hallmark of competing interactions. This is exemplified
in superfluid $^3$He which has multiple thermodynamic phases with spin and
orbital quantum numbers $S=1$ and $L=1$, that emerge on cooling from a nearly
ferromagnetic Fermi liquid. The heavy fermion compound UPt$_3$ exhibits similar
behavior clearly manifest in its multiple superconducting phases. However,
consensus as to its order parameter symmetry has remained elusive. Our small
angle neutron scattering measurements indicate a linear temperature dependence
of the London penetration depth characteristic of nodal structure of the order
parameter. Our theoretical analysis is consistent with assignment of its
symmetry $L=3$ odd parity state for which one of the three thermodynamic phases
in non-zero magnetic field is chiral.


title: Optical conductivity for the surface of a Topological Insulator

abstract:
  The optical conductivity for the surface excitations for a Topological
Insulator as a function of the chemical potential and disorder is considered.
Due to the time reversal symmetry the chiral metallic surface states are
protected against disorder. This allow to use the averaged single particle
Green's function to compute the optical conductivity. We compute the
conductivity in the limit of a finite disorder. We find that the conductivity
as a function of the chemical potential $\mu $ and frequency $\Omega$ is given
by the universal value $\sigma(\Omega>2\mu)= \frac{e^2 \pi}{8h}$. For
frequencies $\Omega< \mu$ and elastic mean free path $l_{el}=v\tau$ which obey
$k_{F}l>1$ we obtain the conductivity is given by
$\sigma(\Omega<2|\mu|)=\frac{e^2}{2h}\frac{k_{F}l_{el}}{(\Omega \tau)^2+1}$. In
the limit of zero disorder we find $\sigma(\mu\neq0,\Omega, k_{F}l\rightarrow
\infty)=\frac{e^2 \pi}{2h}|\mu|\delta(\Omega)$.


title: Linear Network Error Correction Multicast/Broadcast/Dispersion Codes

abstract:
  In this paper, for the purposes of information transmission and network error
correction simultaneously, three classes of important linear network codes in
network coding, linear multicast/broadcast/dispersion codes are generalized to
linear network error correction coding, i.e., linear network error correction
multicast/broadcast/dispersion codes. We further propose the (weakly, strongly)
extended Singleton bounds for these new classes of codes, and define the
optimal codes satisfying the corresponding Singleton bounds with equality,
which are called multicast/broadcast/dispersion MDS codes respectively. The
existence of such codes are proved by an algebraic method and one kind of
constructive algorithm is also proposed.


title: The Failure Probability of Random Linear Network Coding for Networks

abstract:
  In practice, since many communication networks are huge in scale, or
complicated in structure, or even dynamic, the predesigned linear network codes
based on the network topology is impossible even if the topological structure
is known. Therefore, random linear network coding has been proposed as an
acceptable coding technique for the case that the network topology cannot be
utilized completely. Motivated by the fact that different network topological
information can be obtained for different practical applications, we study the
performance analysis of random linear network coding by analyzing some failure
probabilities depending on these different topological information of networks.
We obtain some tight or asymptotically tight upper bounds on these failure
probabilities and indicate the worst cases for these bounds, i.e., the networks
meeting the upper bounds with equality. In addition, if the more topological
information of the network is utilized, the better upper bounds are obtained.
On the other hand, we also discuss the lower bounds on the failure
probabilities.


title: Partial regularity for elliptic systems with VMO-coefficients

abstract:
  We establish partial regularity for vector-valued solutions to inhomogeneous
elliptic systems in divergence form where the coefficients are possibly
discontinuous with respect to $x$. More precisely, we assume a VMO-condition
with respect to the $x$ and continuity with respect to $u$ and prove H\"older
continuity of the solutions outside of singular sets.


title:
Electromagnetic properties of polycrystalline diamond from 35K to room
  temperature and microwave to terahertz frequencies

abstract:
  Dielectric resonators are key components for many microwave and millimetre
wave applications, including high-Q filters and frequency-determining elements
for precision frequency synthesis. These often depend on the quality of the
dielectric material. The commonly used material for building the best cryogenic
microwave oscillators is sapphire. However sapphire is becoming a limiting
factor for higher frequencies design. It is then important to find new
candidates that can fulfil the requirements for millimetre wave low noise
oscillators at room and cryogenic temperatures. These clocks are used as a
reference in many fields, like modern telecommunication systems, radio
astronomy (VLBI), and precision measurements at the quantum limit.
High-resolution measurements were made of the temperature-dependence of the
electromagnetic properties of a polycrystalline diamond disk at temperatures
between 35 K and 330 K at microwave to sub-millimetre wave frequencies. The
cryogenic measurements were made using a TE01{\delta} dielectric mode resonator
placed inside a vacuum chamber connected to a single-stage pulse-tube
cryocooler. The high frequency characterization was performed at room
temperature using a combination of a quasi-optical two-lens transmission setup,
a Fabry-Perot cavity and a whispering gallery mode resonator excited with
waveguides. Our CVD diamond sample exhibits a decreasing loss tangent with
increasing frequencies. We compare the results with well known crystals. This
comparison makes clear that polycrystalline diamond could be an important
material to generate stable frequencies at millimetre waves.


title: Duality in Entanglement-Assisted Quantum Error Correction

abstract:
  The dual of an entanglement-assisted quantum error-correcting (EAQEC) code is
defined from the orthogonal group of a simplified stabilizer group. From the
Poisson summation formula, this duality leads to the MacWilliams identities and
linear programming bounds for EAQEC codes. We establish a table of upper and
lower bounds on the minimum distance of any maximal-entanglement EAQEC code
with length up to 15 channel qubits.


title: Ascent properties for derived functors

abstract:
  Given a flat local ring homomorphism R\to S, and two finitely generated
R-modules M and N, we describe conditions under which the modules Tor^i(M,N)
and Ext^i(M,N) have S-module structures that are compatible with their R-module
structures.


title: Parity-expanded variational analysis for non-zero momentum

abstract:
  In recent years, the use of variational analysis techniques in lattice QCD
has been demonstrated to be successful in the investigation of the rest-mass
spectrum of many hadrons. However, due to parity-mixing, more care must be
taken for investigations of boosted states to ensure that the projected
correlation functions provided by the variational analysis correspond to the
same states at zero momentum. In this paper we present the Parity-Expanded
Variational Analysis (PEVA) technique, a novel method for ensuring the
successful and consistent isolation of boosted baryons through a parity
expansion of the operator basis used to construct the correlation matrix.


title: First order deformations of the Fourier matrix

abstract:
  The $N\times N$ complex Hadamard matrices form a real algebraic manifold
$C_N$. The singularity at a point $H\in C_N$ is described by a filtration of
cones $T^\times_HC_N\subset T^\circ_HC_N\subset
T_HC_N\subset\widetilde{T}_HC_N$, coming from the trivial, affine, smooth and
first order deformations. We study here these cones in the case where $H=F_N$
is the Fourier matrix, $(w^{ij})$ with $w=e^{2\pi i/N}$, our main result being
a simple description of $\widetilde{T}_HC_N$. As a consequence, the rationality
conjecture $dim_\mathbb R(\widetilde{T}_HC_N)=dim_\mathbb
Q(\widetilde{T}_HC_N\cap M_N(\mathbb Q))$ holds at $H=F_N$.


title:
Star Formation and Gas Kinematics of Quasar Host Galaxies at z~6: New
  insights from ALMA

abstract:
  We present ALMA observations of the [C II] 158 micron fine structure line and
dust continuum emission from the host galaxies of five redshift 6 quasars. We
also report complementary observations of 250 GHz dust continuum and CO (6-5)
line emission from the z=6.00 quasar SDSS J231038.88+185519.7. The ALMA
observations were carried out in the extended array at 0.7" resolution. We have
detected the line and dust continuum in all five objects. The derived [C II]
line luminosities are 1.6x10^{9} to 8.8x10^{9} Lsun and the [C II]-to-FIR
luminosity ratios are 3.0-5.6x10^{-4}, which is comparable to the values found
in other high-redshift quasar-starburst systems and local ultra-luminous
infrared galaxies. The sources are marginally resolved and the intrinsic source
sizes (major axis FWHM) are constrained to be 0.3" to 0.6" (i.e., 1.7 to 3.5
kpc) for the [C II] line emission and 0.2" to 0.4" (i.e., 1.2 to 2.3 kpc) for
the continuum. These measurements indicate that there is vigorous star
formation over the central few kpc in the quasar host galaxies. The ALMA
observations also constrain the dynamical properties of the atomic gas in the
starburst nuclei. The intensity-weighted velocity maps of three sources show
clear velocity gradients. Such velocity gradients are consistent with a
rotating, gravitationally bound gas component, although they are not uniquely
interpreted as such. Under the simplifying assumption of rotation, the implied
dynamical masses within the [C II]-emitting regions are of order 10^{10} to
10^{11} Msun. Given these estimates, the mass ratios between the SMBHs and the
spheroidal bulge are an order of magnitude higher than the mean value found in
local spheroidal galaxies, which is in agreement with results from previous CO
observations of high redshift quasars.


title:
Local obstructions to projective surfaces admitting skew-symmetric Ricci
  tensor

abstract:
  The equation determining whether a projective structure admits a connection
in its given projective class that has skew-symmetric Ricci tensor is an
overdetermined system of semi-linear partial differential equations which we
call the projective Einstein-Weyl (pEW) equation. In 2-dimensions, we give
local obstructions for projective surfaces to admit such a connection in its
projective class. The obstructions are the resultants of polynomial equations
that have to be satisfied for there to admit any pEW solution.


title: Quantum Mechanics Without Observers

abstract:
  The measurement problem and the role of observers have plagued quantum
mechanics since its conception. Attempts to resolve these have introduced
anthropomorphic or non-realist notions into physics. A shift of perspective
based upon process theory and utilizing methods from combinatorial games,
interpolation theory and complex systems theory results in a novel realist
version of quantum mechanics incorporating quasi-local, nondeterministic hidden
variables that are compatible with the no-hidden variable theorems and
relativistic invariance, and reproduce the standard results of quantum
mechanics to a high degree of accuracy without invoking observers.


title: On extremisers to a bilinear Strichartz inequality

abstract:
  In this note, we show that a pair of Gaussian functions are extremisers to a
bilinear Strichartz inequality, and unique up to the symmetry group of the
inequality.


title: Radiative capture reactions in lattice effective field theory

abstract:
  We outline a general method for computing nuclear capture reactions on the
lattice. The method consists of two major parts. In this study we detail the
second part which consists of calculating an effective two-body capture
reaction on the lattice at finite volume. We solve this problem by calculating
the two-point Green's function using an infrared regulator and the capture
amplitude to a two-body bound state. We demonstrate the details of this method
by calculating on the lattice the leading M1 contribution to the radiative
neutron capture on proton at low energies using pionless effective field
theory. We find good agreement with exact continuum results.

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


title:
Reduced Dimensionality (4,3)D-hnCOCANH Experiment: An Efficient Backbone
  Assignment tool for NMR studies of Proteins

abstract:
  Sequence specific resonance assignment and secondary structure determination
of proteins form the basis for variety of structural and functional proteomics
studies by NMR. In this context, an efficient standalone method for rapid
assignment of backbone (1H, 15N, 13Ca and 13C') resonances and secondary
structure determination of proteins has been presented here. Compared to
currently available strategies used for the purpose, the method employs only a
single reduced dimensionality (RD) experiment -(4,3)D-hnCOCANH and exploits the
linear combinations of backbone (13Ca and 13C') chemical shifts to achieve a
dispersion relatively better compared to those of individual chemical shifts
(see the text) for efficient and rapid data analysis. Further, the experiment
leads to the spectrum with direct distinction of self (intra-residue) and
sequential (inter-residue) carbon correlation peaks; these appear opposite in
signs and therefore can easily be discriminated without using an additional
complementary experiment. On top of all this, the main strength of the method
is its efficient and robust assignment strategy based on: (a) multiple, but
unidirectional sequential 15N and 13C correlations (i-->i-1) and (b) the
distinctive peak patterns of self and sequential peaks in different
[(F1(13C)-F3(1H) and (F2(15N)-F3(1H)] planes of the 3D spectrum which enable
ready identification of certain specific triplet sequences (see the text) and
thus serve as check points for mapping the stretches of sequentially connected
HSQC cross peaks on to the primary sequence for assigning the resonances
sequence specifically. Overall, the standalone method presented here will be an
important backbone assignment tool for structural and functional proteomics,
protein folding, and drug discovery research programs by NMR.


title: Simple method of light-shift suppression in optical pumping systems

abstract:
  We report a simple method to suppress the light shift in optical pumping
systems. This method uses only frequency modulation of a radio frequency or
microwave source, which is used to excite an atomic resonance, to
simultaneously lock the source frequency to the atomic resonance and lock the
pumping light frequency to suppress the light shift. We experimentally validate
the method in a vapor-cell atomic clock and verify the results through
numerical simulation. This technique can be applied to many optical pumping
systems that experience light shifts. It is especially useful for atomic
frequency standards because it improves long-term performance, reduces the
influence of the laser, and requires less equipment than previous methods.


title: Renormalization group approach to Einstein-Rosen waves

abstract:
  We present a renormalization group analysis to Einstein-Rosen waves or vacuum
spacetimes with whole-cylinder symmetry. It is found that self-similar
solutions appear as fixed points in the renormalization group transformation.
These solutions correspond to the explosive gravitational waves and the
collapsing gravitational waves at late times and early times, respectively.
Based on the linear perturbation analysis of the self-similar solutions, we
conclude that the self-similar evolution is stable as explosive gravitational
waves under the condition of no incoming waves, while it is weakly unstable as
collapsing gravitational waves. The result implies that self-similar solutions
can describe the asymptotic behavior of more general solutions for exploding
gravitational waves and thus extends the similarity hypothesis in general
relativity from spherical symmetry to cylindrical symmetry.


title: Hyperfine frequencies of 87Rb and 133Cs atoms in Xe gas

abstract:
  The microwave resonant frequencies of ground-state 87Rb and 133Cs atoms in Xe
buffer gas are shown to have a relatively large nonlinear dependence on the Xe
pressure, presumably because of RbXe or CsXe van der Waals molecules. The
nonlinear shifts for Xe are opposite in sign to the previously measured shifts
for Ar and Kr, even though all three gases have negative linear shifts. The Xe
data show striking discrepancies with the previous theory for nonlinear shifts.
Most of this discrepancy is eliminated by accounting for the spin-rotation
interaction in addition to the hyperfine-shift interaction in the molecules. To
the limit of our experimental accuracy, the shifts of 87Rb and 133Cs in He, Ne,
and N2 were linear with pressure.


title: The order of principal congruences of a bounded lattice

abstract:
  We characterize the order of principal congruences of a bounded lattice (also
of a complete lattice and of a lattice of length 5) as a bounded ordered set.
We also state a number of open problems in this new field.


title:
A characterization of two weight trace inequalities for positive dyadic
  operators in the upper triangle case

abstract:
  Two weight trace inequalities for positive dyadic operators are characterized
in terms of discrete Wolff's potentials in the upper triangle case.


title:
Gap phenomena for a class of fourth-order geometric differential
  operators on surfaces with boundary

abstract:
  In this paper we establish a gap phenomenon for immersed surfaces with
arbitrary codimension, topology and boundaries that satisfy one of a family of
systems of fourth-order anisotropic geometric partial differential equations.
Examples include Willmore surfaces, stationary solitons for the surface
diffusion flow, and biharmonic immersed surfaces in the sense of Chen. On the
boundary we enforce either umbilic or flat boundary conditions: that the
tracefree second fundamental form and its derivative or the full second
fundamental form and its derivative vanish. For the umbilic boundary condition
we prove that any surface with small L^2-norm of the tracefree second
fundamental form or full second fundamental form must be totally umbilic; that
is, a union of pieces of round spheres and flat planes. We prove that the
stricter smallness condition allows consideration for a broader range of
differential operators. For the flat boundary condition we prove the same
result with weaker hypotheses, allowing more general operators, and a stronger
conclusion: only pieces of planes are allowed. The method used relies only on
the smallness assumption and thus holds without requiring the imposition of
additional symmetries. The result holds in the class of surfaces with any genus
and irrespective of the number or shape of the boundaries.


title: A versatile high resolution objective for imaging quantum gases

abstract:
  We present a high resolution objective lens made entirely from catalog
singlets that has a numerical aperture of 0.36. It corrects for aberrations
introduced by a glass window and has a long working distance of 35mm, making it
suitable for imaging objects within a vacuum system. This offers simple high
resolution imaging for many in the quantum gas community. The objective
achieves a resolution of 1.3{\mu}m at the design wavelength of 780nm, and a
diffraction-limited field of view of 360{\mu}m when imaging through a 5mm
window. Images of a resolution target and a pinhole show quantitative agreement
with the simulated lens performance. The objective is suitable for
diffraction-limited imaging on the D2 line of all the alkalis by changing only
the aperture diameter, retaining numerical apertures above 0.32. The design
corrects for window thicknesses of up to 15mm if the singlet spacings are
modified.


title:
Quadrupole moments of low lying baryons with spin 1/2^+, spin 3/2^+, and
  spin 3/2^+ \to 1/2^+ transitions

abstract:
  The chiral constituent quark model (\chiCQM) with general parameterization
(GP) method has been formulated to calculate the quadrupole moments of the spin
3/2^+ decuplet baryons and spin 3/2^+ \to 1/2^+ transitions. The implications
of such a model have been investigated in detail for the effects of symmetry
breaking and GP parameters pertaining to the two- and three-quark
contributions. It is found that the \chiCQM is successful in giving a
quantitative and qualitative description of the quadrupole moments.


title:
Data Placement and Replica Selection for Improving Co-location in
  Distributed Environments

abstract:
  Increasing need for large-scale data analytics in a number of application
domains has led to a dramatic rise in the number of distributed data management
systems, both parallel relational databases, and systems that support
alternative frameworks like MapReduce. There is thus an increasing contention
on scarce data center resources like network bandwidth; further, the energy
requirements for powering the computing equipment are also growing
dramatically. As we show empirically, increasing the execution parallelism by
spreading out data across a large number of machines may achieve the intended
goal of decreasing query latencies, but in most cases, may increase the total
resource and energy consumption significantly. For many analytical workloads,
however, minimizing query latencies is often not critical; in such scenarios,
we argue that we should instead focus on minimizing the average query span,
i.e., the average number of machines that are involved in processing of a
query, through colocation of data items that are frequently accessed together.
In this work, we exploit the fact that most distributed environments need to
use replication for fault tolerance, and we devise workload-driven replica
selection and placement algorithms that attempt to minimize the average query
span. We model a historical query workload trace as a hypergraph over a set of
data items, and formulate and analyze the problem of replica placement by
drawing connections to several well-studied graph theoretic concepts. We
develop a series of algorithms to decide which data items to replicate, and
where to place the replicas. We show effectiveness of our proposed approach by
presenting results on a collection of synthetic and real workloads. Our
experiments show that careful data placement and replication can dramatically
reduce the average query spans resulting in significant reductions in the
resource consumption.


title:
Microlensing Discovery of a Population of Very Tight, Very Low-mass
  Binary Brown Dwarfs

abstract:
  Although many models have been proposed, the physical mechanisms responsible
for the formation of low-mass brown dwarfs are poorly understood. The
multiplicity properties and minimum mass of the brown-dwarf mass function
provide critical empirical diagnostics of these mechanisms. We present the
discovery via gravitational microlensing of two very low-mass, very tight
binary systems. These binaries have directly and precisely measured total
system masses of 0.025 Msun and 0.034 Msun, and projected separations of 0.31
AU and 0.19 AU, making them the lowest-mass and tightest field brown-dwarf
binaries known. The discovery of a population of such binaries indicates that
brown dwarf binaries can robustly form at least down to masses of ~0.02 Msun.
Future microlensing surveys will measure a mass-selected sample of brown-dwarf
binary systems, which can then be directly compared to similar samples of
stellar binaries.


title: Incomplete exponential sums over exponential functions

abstract:
  We extend some methods of bounding exponential sums of the type
$\displaystyle\sum_{n\le N}e^{2\pi iag^n/p}$ to deal with the case when $g$ is
not necessarily a primitive root. We also show some recent results of Shkredov
concerning additive properties of multiplicative subgroups imply new bounds for
the sums under consideration.


title:
Ole Romer's method still on the stage. The study of two bound eclipsing
  binaries in quintuple system V994 Her

abstract:
  More than three hundred years ago, Ole Romer measured the speed of light only
by observing the periodic shifting of the observed eclipse arrival times of
Jupiter's moons arising from the varying Earth-Jupiter distance. The same
method of measuring the periodic modulation of delays is still used in
astrophysics. The ideal laboratories for this effect are eclipsing binaries.
The unique system V994 Her consists of two eclipsing binaries orbiting each
other. However, until now it was not certain whether these are gravitationally
bound and what their orbital period is. We show that the system is in fact
quintuple and the two eclipsing binaries are orbiting each other with period
about 6.3 years. This analysis was made only from studying the periodic
modulation of the two periods, when during the periastron passage one binary
has an apparently shorter period, while the other one longer, exactly as
required by a theory. Additionally, it was found that both inner eclipsing
pairs orbit with slightly eccentric orbits undergoing a slow apsidal motions
with a period of the order of centuries.


title:
Reduction in Packet Delay Through the use of Common Buffer over
  Distributed Buffer in the Routing Node of NOC Architecture

abstract:
  Performance evaluation of the routing node in terms of latency is the
characteristics of an efficient design of Buffer in input module. It is
intended to study and quantify the behavior of the single packet array design
in relation to the multiple packet array design. The utilization efficiency of
the packet buffer array improves when a common buffer is used instead of
individual buffers in each input port. First Poissons Queuing model was
prepared to manifest the differences in packet delays. The queuing model can be
classified as (M/M/1), (32/FIFO). Arrival rate has been assumed to be Poisson
distributed with a mean arrival rate of 10 x 1000000. The service rate is
assumed to be exponentially distributed with a mean service rate of 10.05 x
1000000. It has been observed that latency in Common Buffer improved by 46
percent over its distributed buffer. A Simulink model later simulated on MATLAB
to calculate the improvement in packet delay. It has been observed that the
delay improved by approximately 40 percent through the use of a common buffer.
A verilog RTL for both common and shared buffer has been prepared and later
synthesized using Design Compiler of SYNOPSYS. In distributed buffer, arrival
of data packet could be delayed by 2 or 4 clock cycles which lead to latency
improvement either by 17 percent or 34 percent in a common buffer


title:
Multi-input Schr\"odinger equation: controllability, tracking, and
  application to the quantum angular momentum

abstract:
  We present a sufficient condition for approximate controllability of the
bilinear discrete-spectrum Schr\"odinger equation exploiting the use of several
controls. The controllability result extends to simultaneous controllability,
approximate controllability in $H^s$, and tracking in modulus. The result is
more general than those present in the literature even in the case of one
control and permits to treat situations in which the spectrum of the
uncontrolled operator is very degenerate (e.g. it has multiple eigenvalues or
equal gaps among different pairs of eigenvalues). We apply the general result
to a rotating polar linear molecule, driven by three orthogonal external
fields. A remarkable property of this model is the presence of infinitely many
degeneracies and resonances in the spectrum preventing the application of the
results in the literature.


title: On some pro-p groups from infinite-dimensional Lie theory

abstract:
  We initiate the study of some pro-p-groups arising from infinite-dimensional
Lie theory. These groups are completions of some subgroups of incomplete
Kac-Moody groups over finite fields, with respect to various completions of
algebraic or geometric origin. We show topological finite generation for the
pro-p Sylow subgroups in many complete Kac-Moody groups. This implies abstract
simplicity of the latter groups. We also discuss with the question of
(non-)linearity of these pro-p groups.


title: A High Rate Tension Device for Characterizing Brain Tissue

abstract:
  The mechanical characterization of brain tissue at high loading velocities is
vital for understanding and modeling Traumatic Brain Injury (TBI). The most
severe form of TBI is diffuse axonal injury (DAI) which involves damage to
individual nerve cells (neurons). DAI in animals and humans occurs at strains >
10% and strain rates > 10/s. The mechanical properties of brain tissues at
these strains and strain rates are of particular significance, as they can be
used in finite element human head models to accurately predict brain injuries
under different impact conditions. Existing conventional tensile testing
machines can only achieve maximum loading velocities of 500 mm/min, whereas the
Kolsky bar apparatus is more suitable for strain rates > 100/s. In this study,
a custom-designed high rate tension device is developed and calibrated to
estimate the mechanical properties of brain tissue in tension at strain rates <
90/s, while maintaining a uniform velocity. The range of strain can also be
extended to 100% depending on the thickness of a sample. The same apparatus can
be used to characterize the dynamic behavior of skin and other soft biological
tissues by using appropriately sized load cells with a capacity of 10 N and
above.


title: Evolution of Protostellar Outflow around Low-mass Protostar

abstract:
  The evolution of protostellar outflow is investigated with resistive
magneto-hydrodynamic nested-grid simulations that cover a wide range of spatial
scales (\sim 1AU - 1pc). We follow cloud evolution from the pre-stellar core
stage until the infalling envelope dissipates long after the protostar
formation. We also calculate protostellar evolution to derive protostellar
luminosity with time-dependent mass accretion through a circumstellar disk. The
protostellar outflow is driven by the first core prior to protostar formation
and is directly driven by the circumstellar disk after protostar formation. The
opening angle of the outflow is large in the Class 0 stage. A large fraction of
the cloud mass is ejected in this stage, which reduces the star formation
efficiency to \sim 50%. After the outflow breaks out from the natal cloud, the
outflow collimation is gradually improved in the Class I stage. The head of the
outflow travels more than \sim 10^5AU in \sim 10^5 yr. The outflow momentum,
energy and mass derived in our calculations agree well with observations. In
addition, our simulations show the same correlations among outflow momentum
flux, protostellar luminosity and envelope mass as those in observations. These
correlations differ between Class 0 and I stages, which is explained by
different evolutionary stages of the outflow; in the Class 0 stage, the outflow
is powered by the accreting mass and acquires its momentum from the infalling
envelope; in the Class I stage, the outflow enters the momentum-driven
snow-plough phase. Our results suggest that protostellar outflow should
determine the final stellar mass and significantly affect the early evolution
of low-mass protostars.


title: Hot electron transport in a strongly correlated transition metal oxide

abstract:
  Oxide heterointerfaces are ideal for investigating strong correlation effects
to electron transport, relevant for oxide-electronics. Using hot-electrons, we
probe electron transport perpendicular to the La$_{0.7}$Sr$_{0.3}$MnO$_{3}$
(LSMO)- Nb-doped SrTiO$_3$ (Nb:STO) interface and find the characteristic
hot-electron attenuation length in LSMO to be 1.48 $\pm$ 0.10 unit cells (u.c.)
at -1.9 V, increasing to 2.02 $\pm$ 0.16 u.c. at -1.3 V at room temperature.
Theoretical analysis of this energy dispersion reveals the dominance of
electron-electron and polaron scattering. Direct visualization of the local
electron transport shows different transmission at the terraces and at the
step-edges.


title:
Dynamic Hubbard model: kinetic energy driven charge expulsion, charge
  inhomogeneity, hole superconductivity, and Meissner effect

abstract:
  Dynamic Hubbard models describe the fact that the wavefunction of an electron
in an atomic orbital expands when a second electron occupies the orbital. These
models give rise to superconductivity driven by lowering of kinetic energy when
the electronic energy band is almost full, with higher transition temperatures
resulting when the ions are negatively charged. We show that the charge
distribution in dynamic Hubbard models can be highly inhomogeneous in the
presence of disorder, and that a finite system will expel {\it negative charge}
from the interior to the surface, and that these tendencies are largest in the
parameter regime where the models give rise to highest superconducting
transition temperatures. High $T_c$ cuprate materials exhibit charge
inhomogeneity and they exhibit tunneling asymmetry, a larger tendency to emit
electrons rather than holes in NIS tunnel junctions. We propose that these
properties, as well as their high $T_c$'s, are evidence that they are governed
by the physics described by dynamic Hubbard models. Below the superconducting
transition temperature the models considered here describe a negatively charged
superfluid and positively charged quasiparticles, unlike the situation in
conventional BCS superconductors where quasiparticles are charge neutral on
average. We examine the temperature dependence of the superfluid and
quasiparticle charges and conclude that spontaneous electric fields should be
observable in the interior and in the vicinity of superconducting materials
described by these models at sufficiently low temperatures. We furthermore
suggest that the dynamics of the negatively charged superfluid and positively
charged quasiparticles in dynamic Hubbard models can provide an explanation for
the Meissner effect observed in superconducting materials.


title: p-process in SNIA

abstract:
  We explore SNIa as p-process sources in the framework of two-dimensional SNIa
models using enhanced s-seed distributions as directly obtained from a sequence
of thermal pulse instabilities. The SNIa WD precursor is assumed to have
reached the Chandrasekhar mass limit in a binary system by mass accretion from
a giant/main sequence companion. We apply the tracer-particle method to
reconstruct the nucleosynthesis from the thermal histories of Lagrangian
particles, passively advected in the hydrodynamic calculations. For each
particle we follow the explosive nucleosynthesis with a detailed nuclear
reaction network. We select tracers within the typical temperature range for
p-process production, 1.5-3.7 109K, and analyse in detail their behaviour,
exploring the influence of different s-process distributions on the p-process
nucleosynthesis. We find that SNIa contribute to a large fraction of p-nuclei,
both the light p-nuclei and the heavy-p nuclei at a quite flat average
production factor. For the first time, the very abundant Ru and Mo p-isotopes
are reproduced at the same level as the heavy p-nuclei. We investigate the
metallicity effect on the p-process production. Starting with a range of
s-seeds distributions obtained for different metallicities, running SNIa
two-dimensional models and using a simple chemical evolution code, we give
estimates of the SNIa contribution to the solar p-process composition. We find
that SNIa contribute for at least 50% at the solar p-nuclei composition, in a
primary way.


title: Review of Nelson's analysis of Bell's theorem

abstract:
  This article contains a review of Nelson's analysis of Bell's theorem. It
shows that Bell's inequalities can be violated with a theory of local random
variables if one accepts that the outcomes of these variables are not
predetermined prior to measurement. The article describes the relation between
Bell's theorem and the Strong Free Will theorem of Conway and Kochen. Then, the
original articles of Bell are analyzed in detail. Following an article of
Faris, it is explained that Bell's work on the hidden variable question in fact
describes two separate theorems. Bell's first theorem says that there can be no
model for the singlet state where an outcome does not depend locally on the
settings of the detector where the outcome was measured. Bell's second theorem
shows that Bell's inequalities can be violated by a theory that is either not
deterministic, or violates causality in the sense of relativity or the free
will assumption of the experimenters. It is shown in detail where Bell
implicitly makes the various locality assumptions that Nelson has shown to be
necessary for deriving Bell's inequality. The article closes by relating the
various assumptions needed to derive Bell's theorem with the reality criterion
of EPR


title:
A Class of Solvable Optimal Stopping Problems of Spectrally Negative
  Jump Diffusions

abstract:
  We consider the optimal stopping of a class of spectrally negative jump
diffusions. We state a set of conditions under which the value is shown to have
a representation in terms of an ordinary nonlinear programming problem. We
establish a connection between the considered problem and a stopping problem of
an associated continuous diffusion process and demonstrate how this connection
may be applied for characterizing the stopping policy and its value. We also
establish a set of typically satisfied conditions under which increased
volatility as well as higher jump-intensity decelerates rational exercise by
increasing the value and expanding the continuation region.


title:
Activation cross-sections of longer lived products of proton induced
  nuclear reactions on manganese up to 70 MeV

abstract:
  In the frame of a systematic study of the activation cross-sections of the
proton induced nuclear reactions, excitation functions of the
55Mn(p,x)154,152gMn,51Cr and 48V were measured up to 70 MeV. Cross-sections
were measured with the activation method using a stacked foil irradiation
technique and high resolution gamma-ray spectrometry. The experimental data are
analyzed and compared to the earlier results and to the prediction of the
EMPIRE-3 as well as the TALYS theoretical model code in the TENDL-2012 library.
From the measured cross-section data integral production yields were
calculated. Practical applications of the cross-sections are discussed.


title:
Time Variability of Emission Lines for Four Active T Tauri Stars (I):
  October--December in 2010

abstract:
  We present optical spectrophotometric monitoring of four active T Tauri stars
(DG Tau, RY Tau, XZ Tau, RW Aur A) at high spectral resolution ($R \ga 1 \times
10^4$), to investigate the correlation between time variable mass ejection seen
in the jet/wind structure of the driving source and time variable mass
accretion probed by optical emission lines. This may allow us to constrain the
understanding of the jet/wind launching mechanism, the location of the
launching region, and the physical link with magnetospheric mass accretion. In
2010, observations were made at six different epochs to investigate how daily
and monthly variability might affect such a study. We perform comparisons
between the line profiles we observed and those in the literature over a period
of decades and confirm the presence of time variability separate from the daily
and monthly variability during our observations. This is so far consistent with
the idea that these line profiles have a long term variability (3-20 years)
related to episodic mass ejection suggested by the structures in the extended
flow components. We also investigate the correlations between equivalent widths
and between luminosities for different lines. We find that these correlations
are consistent with the present paradigm of steady magnetospheric mass
accretion and emission line regions that are close to the star.


title: Molecular gas in high redshift galaxies

abstract:
  Recent observations with the IRAM instruments have allowed to explore the
star formation efficiency in galaxies as a function of redshift, in detecting
and mapping their molecular gas. Some galaxies stand on what is called the
"main sequence", forming stars with a rate that can be sustained over
time-scales of 1 Gyr, some are starbursts, with a much shorter depletion time.
Star formation was more active in the past, partly because galaxies contained a
larger gas fraction, and also because the star formation efficiency was higher.
The global Kennicutt-Schmidt relation was however similar until z \sim 2.5.
Magnification by gravitational lenses have been used to explore in details
galaxies at higher redshift up to 6. Herschel has discovered many of these
candidates, and their redshift has been determined through the CO lines. ALMA
is beginning to extend considerably these redshift searches, with its
broad-band receivers, for a large range of objects too obscured to be seen in
the optical.


title: Terahertz conductivity of twisted bilayer graphene

abstract:
  Using terahertz time-domain spectroscopy, the real part of optical
conductivity [$\sigma_{1}(\omega)$] of twisted bilayer graphene was obtained at
different temperatures (10 -- 300 K) in the frequency range 0.3 -- 3 THz. On
top of a Drude-like response, we see a strong peak in $\sigma_{1} (\omega)$ at
$\sim$2.7 THz. We analyze the overall Drude-like response using a
disorder-dependent (unitary scattering) model, then attribute the peak at 2.7
THz to an enhanced density of states at that energy, that is caused by the
presence of a van Hove singularity arising from a commensurate twisting of the
two graphene layers.


title: Conditioning of Gaussian processes and a zero area Brownian bridge

abstract:
  We generalize the notion of Gaussian bridges by conditioning Gaussian
processes given that certain linear functionals of the sample paths vanish. We
show the equivalence of the laws of the unconditioned and the conditioned
process and by an application of Girsanov's theorem, we show that the
conditioned process follows a stochastic differential equation (SDE) whenever
the unconditioned process does. In the Markovian case, we are able to determine
the coefficients in the SDE of the conditioned process explicitly. Our main
example is Brownian motion on $[0,1]$ pinned down in 0 at time 1 and
conditioned to have vanishing area spanned by the sample paths.


title:
The Relationship between Craig Interpolation and Recursion-Free Horn
  Clauses

abstract:
  Despite decades of research, there are still a number of concepts commonly
found in software programs that are considered challenging for verification:
among others, such concepts include concurrency, and the compositional analysis
of programs with procedures. As a promising direction to overcome such
difficulties, recently the use of Horn constraints as intermediate
representation of software programs has been proposed. Horn constraints are
related to Craig interpolation, which is one of the main techniques used to
construct and refine abstractions in verification, and to synthesise inductive
loop invariants. We give a survey of the different forms of Craig interpolation
found in literature, and show that all of them correspond to natural fragments
of (recursion-free) Horn constraints. We also discuss techniques for solving
systems of recursion-free Horn constraints.


title:
On the geometry and the deformation of shape represented by a piecewise
  continuous B\'ezier curve with application to shape optimization

abstract:
  In this work, we develop a framework based on piecewize B\'ezier curves to
plane shapes deformation and we apply it to shape optimization problems. We
describe a general setting and some general result to reduce the study of a
shape optimization problem to a finite dimensional problem of integration of a
special type of vector field. We show a practical problem where this approach
leads to efficient algorithms.


title: Generation of magnetic fields in Einstein-Aether gravity

abstract:
  Recently the lower bounds of the intergalactic magnetic fields $10^{-16} \sim
10^{-20}$ Gauss are set by gamma-ray observations while it is unlikely to
generate such large scale magnetic fields through astrophysical processes. It
is known that large scale magnetic fields could be generated if there exist
cosmological vector mode perturbations in the primordial plasma. The vector
mode, however, has only a decaying solution in General Relativity if the plasma
consists of perfect fluids. In order to investigate a possible mechanism of
magnetogenesis in the primordial plasma, here we consider cosmological
perturbations in the Einstein-Aether gravity model, in which the aether field
can act as a new source of vector metric perturbations and thus of magnetic
fields. We estimate the angular power spectra of temperature and B-mode
polarization of the Cosmic Microwave Background (CMB) Anisotropies in this
model and put a rough constraint on the aether field parameters from latest
observations. We then estimate the power spectrum of associated magnetic fields
around the recombination epoch within this limit. It is found that the spectrum
has a characteristic peak at $k=0.1 h{\rm Mpc^{-1}}$, and at that scale the
amplitude can be as large as $B\sim 10^{-22}$ Gauss where the upper bound comes
from CMB temperature anisotropies. The magnetic fields with this amplitude can
be seeds of large scale magnetic fields observed today if the sufficient dynamo
mechanism takes place. Analytic interpretation for the power spectra is also
given.


title: On paratopological groups

abstract:
  In this paper, we firstly construct a Hausdorff non-submetrizable
paratopological group $G$ in which every point is a $G_{\delta}$-set, which
gives a negative answer to Arhangel'ski\v{\i}\ and Tkachenko's question
[Topological Groups and Related Structures, Atlantis Press and World Sci.,
2008]. We prove that each first-countable Abelian paratopological group is
submetrizable. Moreover, we discuss developable paratopological groups and
construct a non-metrizable, Moore paratopological group. Further, we prove that
a regular, countable, locally $k_{\omega}$-paratopological group is a discrete
topological group or contains a closed copy of $S_{\omega}$. Finally, we
discuss some properties on non-H-closed paratopological groups, and show that
Sorgenfrey line is not H-closed, which gives a negative answer to
Arhangel'ski\v{\i}\ and Tkachenko's question [Topological Groups and Related
Structures, Atlantis Press and World Sci., 2008]. Some questions are posed.


title: Neutral meson tests of time-reversal symmetry invariance

abstract:
  The laws of quantum physics can be studied under the mathematical operation T
that inverts the direction of time. Strong and electromagnetic forces are known
to be invariant under temporal inversion, however the weak force is not. The
BaBar experiment recently exploited the quantum-correlated production of pairs
of B0 mesons to show that T is a broken symmetry. Here we show that it is
possible to perform a wide range of tests of quark flavour changing processes
under T in order to validate the Standard Model of particle physics covering b
to u, d, s, and c transitions as well as c to u, d and s transitions using
entangled B and D pairs created in Y(4S) and psi(3770) decays. We also note
that pseudoscalar decays to two spin one particle final states provide an
additional set of CP filter bases to use for T violation tests.


title: $\pi$-metrizable spaces and strongly $\pi$-metrizable spaces

abstract:
  A space $X$ is said to be $\pi$-metrizable if it has a $\sigma$-discrete
$\pi$-base. In this paper, we mainly give affirmative answers for two questions
about $\pi$-metrizable spaces. The main results are that: (1) A space $X$ is
$\pi$-metrizable if and only if $X$ has a $\sigma$-hereditarily
closure-preserving $\pi$-base; (2) $X$ is $\pi$-metrizable if and only if $X$
is almost $\sigma$-paracompact and locally $\pi$-metrizable; (3) Open and
closed maps preserve $\pi$-metrizability; (4) $\pi$-metrizability satisfies
hereditarily closure-preserving regular closed sum theorems. Moreover, we
define the notions of second-countable $\pi$-metrizable and strongly
$\pi$-metrizable spaces, and study some related questions. Some questions about
strongly $\pi$-metrizability are posed.


title: A note on free paratopological groups

abstract:
  In this paper, we mainly discuss some generalized metric properties and the
character of the free paratopological groups, and extend several results valid
for free topological groups to free paratopological groups.


title: Herschel observations of INTEGRAL supergiant High Mass X-ray Binaries

abstract:
  We present preliminary results on Herschel/PACS mid/far-infrared photometric
observations of INTEGRAL supergiant High Mass X-ray Binaries (HMXBs), with the
aim of detecting the presence and characterizing the nature of absorbing
material (dust and/or cold gas), either enshrouding the whole binary systems,
or surrounding the sources within their close environment. These unique
observations allow us to better characterize the nature of these HMXBs, to
constrain the link with their environment (impact and feedback), and finally to
get a better understanding of the formation and evolution of such rare and
short-living supergiant HMXBs in our Galaxy.


title:
An INTEGRAL view of High Mass X-ray Binaries : their nature, formation
  and evolution

abstract:
  We describe here the nature, formation and evolution of the supergiant high
mass X-ray binary (HMXB) population, i.e. systems accreting the stellar wind of
supergiant stars. There are now many new observations, from the high-energy
side (mainly from the INTEGRAL satellite), complemented by multi-wavelength
observations (mainly in the optical, near and mid-infrared from ESO
facilities), showing that a new population of supergiant HMXBs has been
recently revealed. We report here on the observational facts about the
different categories of HMXBs, allowing to build a consistent scenario
explaining the various characteristics of these sources, based on models of
accretion in these sources (e.g. transitory accretion disc versus clumpy
winds). We also mention new observations suggesting the existence of
evolutionary links between Be and stellar wind accreting supergiant X-ray
binaries.


title: Asymptotic periodicity of flows in time-depending networks

abstract:
  We consider a linear transport equation on the edges of a network with
time-varying coefficients. Using methods for non-autonomous abstract Cauchy
problems, we obtain well-posedness of the problem and describe the asymptotic
profile of the solutions under certain natural conditions on the network. We
further apply our theory to a model used for air traffic flow management.


title:
Spin-charge-orbital ordering in hollandite-type manganites studied by
  model Hartree-Fock calculation

abstract:
  We investigate spin-charge-orbital ordering in a Mn$^{3+}$/Mn$^{4+}$ mixed
valence state on a hollandite-type lattice using unrestricted Hartree-Fock
calculation on a multi-band Mn 3$d$-O 2$p$ lattice model. The calculations show
that the Mn$^{3+}$-Mn$^{4+}$ double exchange interaction, the
Mn$^{3+}$-Mn$^{3+}$ and Mn$^{4+}$-Mn$^{4+}$ superexchange interactions are
ferromagnetic and play important roles to stabilize the charge and orbital
ordering pattern. The most stable charge and orbital ordering pattern is
consistent with the $1\times1\times1$ orthorhombic or monoclinic structure of
K$_{1.6}$Mn$_8$O$_{16}$.


title: Nonparametric regression for locally stationary time series

abstract:
  In this paper, we study nonparametric models allowing for locally stationary
regressors and a regression function that changes smoothly over time. These
models are a natural extension of time series models with time-varying
coefficients. We introduce a kernel-based method to estimate the time-varying
regression function and provide asymptotic theory for our estimates. Moreover,
we show that the main conditions of the theory are satisfied for a large class
of nonlinear autoregressive processes with a time-varying regression function.
Finally, we examine structured models where the regression function splits up
into time-varying additive components. As will be seen, estimation in these
models does not suffer from the curse of dimensionality.


title: Analysis of the heat kernel of the Dirichlet-to-Neumann operator

abstract:
  We prove Poisson upper bounds for the kernel $K$ of the semigroup generated
by the Dirichlet-to-Neumann operator if the underlying domain is bounded and
has a $C^\infty$-boundary. We also prove Poisson bounds for $K_z$ for all $z$
in the right half-plane and for all its derivatives.


title: Some weak versions of the $M_{1}$-spaces

abstract:
  We mainly introduce some weak versions of the $M_{1}$-spaces, and study some
properties about these spaces. The mainly results are that: (1) If $X$ is a
compact scattered space and $i(X)\leq 3$, then $X$ is an $s$-$m_{1}$-space; (2)
If $X$ is a strongly monotonically normal space, then $X$ is an
$s$-$m_{2}$-space; (3) If $X$ is a $\sigma$-$m_{3}$ space, then $t(X)\leq
c(X)$, which extends a result of P.M. Gartside in \cite{CP}. Moreover, some
questions are posed in the paper.


title: The Future of Mobile Security

abstract:
  Mobile devices are more than just phones, they are a lifeline to the outdoor
world, entertainment platform, GPS system, a little black book and a shopping
and banking tool. What is not well known is that these devices are also
gateways. Mobile devices can be used by a hacker as an access point into many
other aspects of your digital life as well the lives of others in your network,
making mobile security about more than just protecting your phone. This is an
overview of technologies supporting mobile data cryptography and two-step
protection mechanisms that may be used to secure online transactions and user
authentication.


title:
On the relationship between the size and surface coverage of starspots
  on magnetically active low-mass stars

abstract:
  We present a model that predicts the light curve amplitude distribution for
an ensemble of low-mass magnetically active stars, under the assumptions that
stellar spin axes are randomly orientated and that cool starspots have a
characteristic scale length and are randomly distributed across the stellar
surfaces. The model is compared with observational data for highly magnetically
active M-dwarfs in the young cluster NGC 2516. We find that the best fitting
starspot scale length is not constrained by these data alone, but requires
assumptions about the overall starspot filling factor and starspot temperature.
Assuming a spot coverage fraction of 0.4+/-0.1 and a starspot to unspotted
photosphere temperature ratio of 0.7+/-0.05, as suggested by the inflated radii
of these stars compared to evolutionary model predictions and by TiO band
measurements on other active cool stars of earlier spectral type, the
best-fitting starspot angular scale length is 3.5(+2)(-1) degrees, or a linear
scale length of \sim 25000 km. This linear scale length is similar to large
sunspot groups, but 2--5 times smaller than the starspots recently deduced on
an active G-dwarf using eclipse mapping by a transiting exoplanet. However, the
best-fitting spot scale length in the NGC 2516 M-dwarfs increases with the
assumed spot temperature ratio and with the inverse square root of the assumed
spot filling factor. Hence the light curve amplitude distribution might equally
well be described by these larger spot scale lengths if the spot filling
factors are <0.1 or the spot temperature ratio is >0.9.


title:
Double Vogan superdiagrams of Lie superalgebras and symmetric
  superspaces

abstract:
  A Vogan superdiagram is a set of involution and painting on a Dynkin diagram.
It selects a real form, or equivalently an involution, from a complex simple
Lie superalgebra. We introduce the double Vogan superdiagram, which is two sets
of Vogan superdiagrams superimposed on an affine Dynkin diagram. They
correspond to pairs of commuting involutions on complex simple Lie
superalgebras, and therefore provide an independent classification of the
simple locally symmetric or symmetric superpairs.


title:
$\pi^+ \pi^-$ and $\pi^0 \pi^0$ pair production in photon-photon and in
  ultraperipheral ultrarelativistic heavy ion collisions

abstract:
  We discuss ${\gamma}{\gamma}\to {\pi}{\pi}$ reactions, starting from the
two-pion threshold up to about $\sqrt{s_{{\gamma}{\gamma}}}$ = 6 GeV. We
include the dipion continuum due to pion exchange (for ${\pi}^+{\pi}^-$) and
${\rho}^\pm$ exchange (for ${\pi}^0{\pi}^0$) as well as the dipion
${\sigma}(600)$, $f_0(980)$ and $f_2(1270)$ s-channel resonances. We discuss
also a possible contribution of less pronounced scalar resonances $f_0(1500)$
and $f_0(1710)$ as well as the tensor resonances $f'_2(1525)$, $f_2(1565)$ and
$f_2(1950)$. We find that the inclusion of the spin-four $f_4(2050)$ resonant
state improves the situation at $\sqrt{s_{{\gamma}{\gamma}}} \approx$ 2 GeV. We
estimate the relevant diphoton partial decay width to be ${\Gamma}_{f_4 \to
{\gamma}{\gamma}} \approx$ 0.7 keV. At higher energies, Brodsky-Lepage and
hand-bag mechanisms are included in addition. We nicely describe the world data
for ${\gamma}{\gamma}\to {\pi}{\pi}$ for the first time both for the total
cross section and angular distributions.
  The cross section for the production of two-pions in ultraperipheral
ultrarelativistic heavy ion collisions is calculated in the impact parameter
space Equivalent Photon Approximation (EPA). We obtain the nuclear cross
section of 46.7 mb for ${\pi}^+{\pi}^-$ and 8.7 mb for ${\pi}^0{\pi}^0$ at the
LHC energy $\sqrt{s_{NN}} =$ 3.5 TeV and minimal cut on pion transverse
momentum $p_t>$ 0.2 GeV. Differential distributions in impact parameter, dipion
invariant mass, single pion and dipion rapidity, pion transverse momentum as
well as pion pseudorapidity are shown. The ${\gamma}{\gamma}\to {\pi}^+
{\pi}^-$ subprocess constitutes a background to $A A \to A {\rho}^0 (\to
{\pi}^+ {\pi}^-) A$ process.


title: Fresh-Variable Automata for Service Composition

abstract:
  To model Web services handling data from an infinite domain, or with multiple
sessions, we introduce fresh-variable automata, a simple extension of
finite-state automata in which some transitions are labeled with variables that
can be refreshed in some specified states. We prove several closure properties
for this class of automata and study their decision problems. We then introduce
a notion of simulation that enables us to reduce the Web service composition
problem to the construction of a simulation of a target service by the
asynchronous product of existing services, and prove that this construction is
computable.


title:
Andreev bound states and current-phase relations in three-dimensional
  topological insulators

abstract:
  To guide the search for the Majorana fermion, we theoretically study
superconductor/topological/superconductor (S/TI/S) junctions in an
experimentally relevant regime. We find that the striking features present in
these systems, including the doubled periodicity of the Andreev bound states
(ABSs) due to tunneling via Majorana states, can still be present at high
electron densities. We show that via the inclusion of magnetic layers, this 4pi
periodic ABS can still be observed in three-dimensional topological insulators,
where finite angle incidence usually results in the opening of a gap at zero
energy and hence results in a 2pi periodic ABS. Furthermore, we study the
Josephson junction characteristics and find that the gap size can be controlled
and decreased by tuning the magnetization direction and amplitude. These
findings pave the way for designing experiments on S/3DTI/S junctions.


title: A composition theorem for decision tree complexity

abstract:
  We completely characterise the complexity in the decision tree model of
computing composite relations of the form h = g(f^1,...,f^n), where each
relation f^i is boolean-valued. Immediate corollaries include a direct sum
theorem for decision tree complexity and a tight characterisation of the
decision tree complexity of iterated boolean functions.


title: Charm mixing in the Standard Model: the inclusive approach

abstract:
  The talk reviews the status of Standard Model predictions for lifetimes and
mixing rates of charmed mesons. I discuss sources of SU(3) breaking in the
hadron state affecting the Delta C = 2 Hamiltonian and argue that they are the
dominant effect generating a D0 decay width splitting.


title: On The b-Chromatic Number of Regular Bounded Graphs

abstract:
  A $b$-coloring of a graph is a proper coloring such that every color class
contains a vertex adjacent to at least one vertex in each of the other color
classes. The $b$-chromatic number of a graph $G$, denoted by $b(G)$, is the
maximum integer $k$ such that $G$ admits a $b$-coloring with $k$ colors. El
Sahili and Kouider conjectured that $b(G)=d+1$ for $d$-regular graph with girth
5, $d\geq4$. In this paper, we prove that this conjecture holds for $d$-regular
graph with at least $d^3+d$ vertices. More precisely we show that $b(G)=d+$1
for $d$-regular graph with at least $d^3+d$ vertices and containing no cycle of
order 4. We also prove that $b(G)=d+1$ for $d$-regular graphs with at least
$2d^3+2d-2d^2$ vertices improving Cabello and Jakovac bound.


title: Exponential Sums over Points of Elliptic Curves

abstract:
  We derive a new bound for some bilinear sums over points of an elliptic curve
over a finite field. We use this bound to improve a series of previous results
on various exponential sums and some arithmetic problems involving points on
elliptic curves.


title: Multivariate varying coefficient model for functional responses

abstract:
  Motivated by recent work studying massive imaging data in the neuroimaging
literature, we propose multivariate varying coefficient models (MVCM) for
modeling the relation between multiple functional responses and a set of
covariates. We develop several statistical inference procedures for MVCM and
systematically study their theoretical properties. We first establish the weak
convergence of the local linear estimate of coefficient functions, as well as
its asymptotic bias and variance, and then we derive asymptotic bias and mean
integrated squared error of smoothed individual functions and their uniform
convergence rate. We establish the uniform convergence rate of the estimated
covariance function of the individual functions and its associated eigenvalue
and eigenfunctions. We propose a global test for linear hypotheses of varying
coefficient functions, and derive its asymptotic distribution under the null
hypothesis. We also propose a simultaneous confidence band for each individual
effect curve. We conduct Monte Carlo simulation to examine the finite-sample
performance of the proposed procedures. We apply MVCM to investigate the
development of white matter diffusivities along the genu tract of the corpus
callosum in a clinical study of neurodevelopment.


title:
Bosonic Part of 4d N=1 Supersymmetric Gauge Theory with General
  Couplings: Local Existence

abstract:
  In this paper, we prove the local existence of the bosonic part of N=1
supersymmetric gauge theory in four dimensions with general couplings. We start
with the Lagrangian of the vector and chiral multiplets with general couplings
and scalar potential turned on. Then, for the sake of simplicity, we set all
fermions vanish at the level of equations of motions, so we only have the
bosonic parts of the theory. We apply Segal's general theory to show the local
existence of solutions of equations of motions by taking Kahler potential to be
bounded above by U(n) symmetric Kahler potential and the first derivative of
gauge couplings to be at most linear growth functions.


title: A Robust AFPTAS for Online Bin Packing with Polynomial Migration

abstract:
  In this paper we develop general LP and ILP techniques to find an approximate
solution with improved objective value close to an existing solution. The task
of improving an approximate solution is closely related to a classical theorem
of Cook et al. in the sensitivity analysis for LPs and ILPs. This result is
often applied in designing robust algorithms for online problems. We apply our
new techniques to the online bin packing problem, where it is allowed to
reassign a certain number of items, measured by the migration factor. The
migration factor is defined by the total size of reassigned items divided by
the size of the arriving item. We obtain a robust asymptotic fully polynomial
time approximation scheme (AFPTAS) for the online bin packing problem with
migration factor bounded by a polynomial in $\frac{1}{\epsilon}$. This answers
an open question stated by Epstein and Levin in the affirmative. As a byproduct
we prove an approximate variant of the sensitivity theorem by Cook at el. for
linear programs.


title:
The $b$-Chromatic Number and $f$-Chromatic Vertex Number of Regular
  Graphs

abstract:
  The $b$-chromatic number of a graph $G$, denoted by $b(G)$, is the largest
positive integer $k$ such that there exists a proper coloring for G with $k$
colors in which every color class contains at least one vertex adjacent to some
vertex in each of the other color classes, such a vertex is called a dominant
vertex. The $f$-chromatic vertex number of a $d$-regular graph $G$, denoted by
$f(G)$, is the maximum number of dominant vertices of distinct colors in a
proper coloring with $d+1$ colors. El Sahili and Kouider conjectured that
$b(G)=d+1$ for any $d$-regular graph $G$ of girth 5. We study this conjecture
by giving some partial answers under supplementary conditions.


title: Description of the \psi(3770) resonance interfering with the background

abstract:
  The parameters of the interfering $\psi(3770)$ resonance should be determined
from the data on the reactions $e^+e^-$\,$\to$\,$D\bar D$ with the use of the
models satisfying the elastic unitarity requirement. The selection of such
models can be realized by comparing their predictions with the relevant data on
the shape of the $\psi(3770)$ peak in the non-$D\bar D$ decay channels. Here,
we illustrate this unitarity approach by the example of the most simple variant
of the model of the mixed $\psi(3770)$ and $\psi(2S)$ resonances. When new
high-statistics data become available, it will be interesting to test this
clarity variant.


title: Online Checkpointing with Improved Worst-Case Guarantees

abstract:
  In the online checkpointing problem, the task is to continuously maintain a
set of k checkpoints that allow to rewind an ongoing computation faster than by
a full restart. The only operation allowed is to replace an old checkpoint by
the current state. Our aim are checkpoint placement strategies that minimize
rewinding cost, i.e., such that at all times T when requested to rewind to some
time t <= T the number of computation steps that need to be redone to get to t
from a checkpoint before t is as small as possible. In particular, we want that
the closest checkpoint earlier than t is not further away from t than q_k times
the ideal distance T / (k+1), where q_k is a small constant.
  Improving over earlier work showing 1 + 1/k <= q_k <= 2, we show that q_k can
be chosen asymptotically less than 2. We present algorithms with asymptotic
discrepancy q_k <= 1.59 + o(1) valid for all k and q_k <= ln(4) + o(1) <= 1.39
+ o(1) valid for k being a power of two. Experiments indicate the uniform bound
p_k <= 1.7 for all k. For small k, we show how to use a linear programming
approach to compute good checkpointing algorithms. This gives discrepancies of
less than 1.55 for all k < 60.
  We prove the first lower bound that is asymptotically more than one, namely
q_k >= 1.30 - o(1). We also show that optimal algorithms (yielding the infimum
discrepancy) exist for all k.


title:
Revisiting interferences for measuring and optimizing optical
  nonlinearities

abstract:
  A method based on optical interferences for measuring optical nonlinearities
is presented. In a proof-of-principle experiment, the technique is applied to
the experimental determination of the intensity dependence of the
photoionization process. It is shown that it can also be used to control and
optimize the nonlinear process itself at constant input energy. The presented
strategy leads to enhancements that can reach several orders of magnitude for
highly nonlinear processes.


title: Recent progress in the Calderon problem with partial data

abstract:
  We survey recent results on Calderon's inverse problem with partial data,
focusing on three and higher dimensions.


title: Labeled Packing of Non Star Tree into its Fifth Power and Sixth Power

abstract:
  In this paper we prove that we can find a labeled packing of a non star tree
$T$ into $T^6$ with $m_T+\lceil\frac{n-m_T}{5}\rceil$ labels, where $n$ is the
number of vertices of $T$ and $m_T$ is the maximum number of leaves that can be
removed from $T$ in such a way that the obtained graph is a non star tree.
Also, we prove that we can find a labeled packing of a non star tree $T$ into
$T^5$ with $m_T+1$ labels and a labeled packing of a path $P_n$, $n\geq 4$,
into $P_n^4$ with $\lceil \frac{n}{4}\rceil$ labels.